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I. Introduction: Start the Journey of Exploring Roots Blowers
On the grand stage of industry, Roots blowers are like a low-key but indispensable behind-the-scenes hero. Although they rarely become the focus of the spotlight, they silently play an irreplaceable key role in many key areas. From providing indispensable aeration power for sewage purification in sewage treatment plants, to helping food drying and transportation in food processing workshops, to participating in various complex chemical reactions in chemical production processes, Roots blowers are everywhere. It is like an "invisible bridge" in the industrial field, closely connecting the production links to ensure that all processes run in an orderly manner. Although we may rarely come into direct contact with Roots blowers in daily life, they are closely related to our lives and affect all aspects of our lives, from the quality of our daily drinking water to the processing and preservation of food on the table. However, for such a device that frequently appears in industry and life, many people know very little about its working principle, unique functions and wide application. It seems to be shrouded in a mysterious veil, full of unknowns and mysteries. Next, let us unveil this veil and explore the wonderful world of Roots blowers to understand how they perform "magic" in various fields and contribute to our lives and industrial development.
II. Understanding Roots blowers: basic information revealed
(I) Definition and concept
Roots blowers, full name Roots blowers, are a typical positive displacement blower from a professional definition perspective. The core feature of a positive displacement blower is that it achieves gas suction, compression and discharge by periodically changing the volume of the studio. Roots blowers use two or more blade-shaped rotors to move relative to each other in the cylinder to achieve this series of gas processing operations.
In industrial production, gas transportation and compression are extremely critical links. Roots blowers are like a precise "gas carrier" that can stably transport gas from one place to another and compress the gas according to process requirements. Taking the sewage treatment plant as an example, the Roots blower is responsible for delivering air to the aeration tank to provide sufficient oxygen for microorganisms to promote the decomposition of organic matter in the sewage. Here, the gas delivery and compression functions of the Roots blower have become the key support for the effective operation of the sewage treatment process. For example, in the pneumatic conveying system, the high-pressure gas generated by the Roots blower can transport materials such as grain and cement through pipelines over long distances, realize the efficient transfer of materials, and greatly improve production efficiency. Its existence enables many industrial processes that rely on gas transmission and compression to operate stably and efficiently, and has become an indispensable and important equipment in industrial production.
(II) Review of the development process
The development history of the Roots blower is like a magnificent industrial epic, and its origin can be traced back to the mid-19th century. In 1854, the American brothers Francis and Philander Roots accidentally invented this unique blower while designing a water wheel, opening up a new development path for the blower field. Initially, Roots blowers were mainly used in the field of mine ventilation, delivering fresh air to underground workers and ensuring the safety of mining operations. In 1877, a Roots blower installed in a British mine had a rotor diameter of 7.65 meters, a rotor length of 4 meters, a speed of 18 rpm, a flow rate of 2870m³/min, and a pressure of 127 mm water column. This was considered a large-scale ventilation equipment at the time, demonstrating the important role of Roots blowers in mine ventilation.
In the 1930s, with the continuous advancement of industrial technology and the gradual expansion of industrial production scale, the application field of Roots blowers began to gradually expand. It is no longer limited to mine ventilation, but has gradually emerged in many industrial sectors such as steel, mining, food, fiber, papermaking, and chemicals, taking on the important task of conveying various gases. In the process of steel smelting, Roots blowers provide sufficient oxygen for blast furnaces, promote the reduction of iron ore and the smelting of molten iron; in chemical production, they participate in various chemical reactions, provide the required gas raw materials for the reaction or transport the gas products produced by the reaction.
In the 1960s, Sulzer Company in Switzerland conducted a systematic and in-depth study on Roots blowers and achieved major technological breakthroughs. This study successfully increased the positive pressure of Roots blowers to 10,000 mm water column and the negative pressure to -6,000 mm water column, and the speed reached 1,000 - 4,000 rpm without water cooling. This technological innovation has greatly expanded the performance range and application scenarios of Roots blowers, enabling them to adapt to more complex and harsh industrial production environments. Since then, the United States, the United Kingdom, Japan and other countries have increased their investment in the research of the performance and structure of Roots blowers, and continuously promoted their technological progress and innovative development.
In China, the development of Roots blowers began in 1951. From the initial imitation and digestion and absorption to the later independent design and manufacturing, we have gradually established our own Roots blower industry system. In the 1960s and 1970s, Changsha Blower Factory developed the D series air-cooled blowers and SD series water-cooled blowers, marking the beginning of the formation of a formal series of domestic Roots blowers. In the early 1980s, several blower factories jointly designed the L series Roots blowers, further enriching the product types of domestic Roots blowers. In 1987, Changsha Blower Factory introduced the design and manufacturing technology of Roots blowers (vacuum pumps) from Japan, injecting new vitality into the improvement of domestic Roots blower technology. Since then, domestic Roots blower technology development activities have become increasingly active, and new product series and technological innovations have been continuously launched, such as the SR series three-leaf blowers, R-CT series single-stage high-pressure blowers, etc., which have filled the domestic gaps and enabled my country's Roots blower manufacturing industry to gradually enter the track of synchronous development with international counterparts.
(III) In-depth analysis of the working principle
1. Analysis of structural composition
Although the structure of the Roots blower is not complicated, it is very delicate. Each component performs its own duties and cooperates with each other to realize the core function of the blower. It is mainly composed of casing, impeller, motor, transmission device, wall panel, oil tank and muffler.
The casing is the main supporting structure of the Roots blower. It is usually made of cast iron or steel plate. It has sufficient strength and rigidity to not only withstand the gas pressure inside the blower, but also resist possible external impact and load. It is like a solid fortress, providing a stable working space for key components such as the internal impeller and wall panel, while also ensuring the sealing of the inside of the blower, preventing gas leakage and ensuring the normal operation of the blower.
The impeller is the core component of the Roots blower, like the "heart" of the blower, usually made of aluminum alloy or cast iron. Impellers are divided into two types: two-blade and three-blade. At present, three-blade impellers have gradually become the mainstream choice in the market due to their significant advantages such as smaller air pulsation, lower noise, and smoother operation. There is a tiny gap between the blades of the impeller. This design is crucial to ensure that the impellers will not collide with each other during high-speed rotation and to achieve smooth gas transportation. The impellers maintain the correct phase through synchronous gears. Driven by the motor, the two impellers rotate synchronously at the same speed and in opposite directions, thereby achieving gas suction, compression and discharge.
As the power source of the Roots blower, the motor provides a strong driving force for the operation of the blower. The performance and parameters of the motor directly affect the operating efficiency and stability of the blower. Roots blowers of different specifications and models need to be matched with motors of corresponding power and characteristics to ensure that the blower can meet the use requirements under various working conditions. For example, in some industrial applications with high requirements for air volume and pressure, it is necessary to equip high-power, high-performance motors to ensure that the Roots blower can operate stably and provide sufficient gas flow and pressure.
The transmission device plays the role of a bridge between the motor and the impeller, responsible for transmitting the power of the motor to the impeller so that the impeller can rotate at high speed. Common transmission devices include belt drive and direct drive. Belt drive has the advantages of simple structure, low cost, easy installation and maintenance, etc. It can effectively buffer the impact during the start-up and operation of the motor and protect the motor and other parts of the fan; direct drive has the characteristics of high transmission efficiency and good stability, which can ensure that the power of the motor is directly and efficiently transmitted to the impeller, and is suitable for some occasions with high requirements for transmission accuracy and efficiency.
The wall panel is used to connect the casing and the impeller and provide stable support for the rotation of the impeller. At the same time, the wall panel also bears the important responsibility of end face sealing, which can effectively prevent gas leakage inside the fan, ensure that the gas is compressed and transported inside the fan according to the predetermined path, and improve the working efficiency and performance of the fan.
The oil tank is mainly used to store lubricating oil, which shoulders the important mission of lubricating gears and bearings. During the operation of the fan, the gears and bearings need to move relative to each other constantly. The lubricating oil can form a thin oil film between them, reduce friction and wear, reduce energy loss, improve the operating efficiency of the fan, and extend the service life of the fan.
The muffler is an indispensable component of the Roots blower. Its main function is to reduce the noise generated by the pulsation of air flow during the intake and exhaust process of the fan. When the Roots blower is working, the rapid flow of gas and pressure changes will generate a lot of noise, which will not only cause noise pollution to the surrounding environment, but also may affect the health and work efficiency of the operator. The muffler can effectively absorb and reduce these noises through special structural design and sound-absorbing materials, making the operation of the fan quieter and more environmentally friendly.
2. Detailed explanation of the operating mechanism
The operating mechanism of the Roots blower is based on the relative movement of the two blade-shaped rotors in the cylinder. When the motor is started, the driving shaft is driven to rotate through the transmission device, and the active impeller on the driving shaft rotates accordingly. At the same time, the driving shaft drives the driven shaft through a pair of synchronous gears, so that the driven impeller rotates synchronously at the same speed and in the opposite direction as the active impeller.
During the rotation of the impeller, due to the tiny gaps between the impeller and the impeller, the impeller and the casing, and the impeller and the wallboard, when the impeller starts to rotate, a vacuum state will be formed at the air inlet. At this time, under the action of atmospheric pressure, air is sucked into the air inlet cavity. As the impeller continues to rotate, two blades of each impeller form a sealed cavity with the wallboard and the casing, and the air in the air inlet cavity is continuously brought to the exhaust cavity by the sealed cavity formed by the two blades. In the exhaust cavity, the impellers mesh with each other, squeezing out the air between the two blades and discharging it from the exhaust port. In this way, the Roots blower realizes the continuous intake, compression and discharge of gas, and continuously provides the required gas for industrial production.
In order to understand this process more intuitively, we can compare the working process of the Roots blower to two gear pumps that cooperate with each other. In the gear pump, the rotation of the gear sucks the liquid from the inlet, and then squeezes the liquid to the outlet through the meshing of the gear. The impeller of the Roots blower is like the gear in the gear pump, which realizes the gas transportation through relative motion. However, the gaps between the impellers of the Roots blower, and between the impeller and the casing and wall panels need to be strictly controlled to ensure the sealing and transmission efficiency of the gas. If the gap is too large, it will cause gas leakage and reduce the pressure and flow of the blower; if the gap is too small, the impeller may rub and collide during rotation, damaging the blower components.
III. Roots blower performance parameters: quantitative embodiment of functions
The performance parameters of Roots blowers, like their "capability labels", are the specific quantitative embodiment of their functions. These parameters not only reflect the performance level of the blowers, but are also an indispensable basis for selection, use and maintenance. Different application scenarios have different requirements for the performance parameters of Roots blowers. Only by deeply understanding the meaning and relationship of these parameters can we accurately select and use Roots blowers so that they can give full play to their best performance in various industrial production. Next, let's analyze the key performance parameters of Roots blowers one by one.
(I) Air volume: measurement of gas delivery volume
Air volume, as one of the key performance parameters of Roots blowers, refers to the volume of gas passing through the blower per unit time. In the industrial field, the unit of air volume is usually expressed in cubic meters per hour (m³/h) or cubic meters per minute (m³/min), and in some specific application scenarios, cubic feet per minute (CFM) is also used to measure. For example, in a sewage treatment plant, in order to meet the oxygen demand of microorganisms in the aeration tank, the Roots blower needs to provide sufficient air volume to continuously transport air to the aeration tank. At this time, the unit of air volume may be cubic meters per hour; in some small pneumatic conveying systems, due to the relatively small amount of material transported, the air volume requirement is relatively low, and the air volume unit may be cubic meters per minute.
Air volume plays a pivotal role in the functional realization of the Roots blower, which is directly related to the gas conveying capacity of the blower. In the sewage treatment process, the appropriate air volume can ensure that the microorganisms in the aeration tank obtain sufficient oxygen, thereby effectively decomposing the organic matter in the sewage and improving the sewage treatment efficiency. If the air volume is insufficient, the microorganisms will not be able to work normally due to lack of oxygen, resulting in the inability to fully decompose the organic matter in the sewage, affecting the purification effect of the water quality; on the contrary, if the air volume is too large, it will not only cause energy waste, but also may have an adverse effect on the microbial community in the aeration tank, destroying the ecological balance of sewage treatment.
In the pneumatic conveying system, the size of the air volume determines the material conveying volume and conveying speed. Taking grain transportation as an example, it is necessary to reasonably select the air volume of the Roots blower according to factors such as the type of grain being transported, the transportation distance and the transportation volume. If the air volume is too small, the grain cannot be transported smoothly in the pipeline, which may cause pipeline blockage and affect production efficiency; if the air volume is too large, although it can increase the transportation speed, it may cause damage to the grain and reduce the quality of the grain. Therefore, in different application scenarios, accurately determining and controlling the air volume of the Roots blower is the key to ensuring that its function can be effectively realized.
(II) Wind pressure: the key to overcoming resistance
Wind pressure refers to the gas pressure generated by the Roots blower, and its unit is usually expressed in Pascal (Pa). In some specific occasions, millimeters of water column (mmH₂O) are also used to measure. The pressure of the blower is divided into three forms: static pressure, dynamic pressure and total pressure. Static pressure refers to the pressure that overcomes the resistance of the pipeline, which can ensure that the gas flows steadily in the pipeline; dynamic pressure refers to the form in which the kinetic energy required in the gas flow is converted into pressure, which is closely related to the flow rate of the gas; total pressure refers to the mechanical energy obtained by the air after passing through the Roots blower, which is equal to the outlet total pressure of the blower (the sum of the outlet static pressure and the outlet dynamic pressure) minus the inlet total pressure of the blower (the sum of the inlet static pressure and the inlet dynamic pressure).
Wind pressure plays a vital role in the working process of the Roots blower. It is the key factor for the blower to overcome the system resistance and realize gas transportation. In industrial production, when the gas flows in the pipeline, it will encounter various resistances, such as the friction resistance of the pipeline, the local resistance of the elbow and the valve, etc. The Roots blower needs to provide sufficient wind pressure to overcome these resistances and transport the gas to the designated location. For example, in chemical production, the Roots blower needs to transport the reaction gas to the high-pressure reactor. At this time, the blower needs to have a higher wind pressure to overcome the high pressure in the reactor and the resistance of the pipeline, so as to ensure that the reaction gas can smoothly enter the reactor and participate in the chemical reaction.
Different application scenarios have different requirements for wind pressure. In the aeration system of sewage treatment, due to the large water depth in the aeration tank, the gas needs to overcome the static pressure of the water to reach the water surface, so the Roots blower is required to provide a certain wind pressure. Generally speaking, the wind pressure required for the aeration system is between 40 and 80 kPa, and the specific value depends on factors such as the depth of the aeration tank, the type and layout of the aerator. In the pneumatic conveying system, the wind pressure requirements vary according to factors such as the nature of the conveyed material, the conveying distance and the layout of the pipeline. For some light and fluid materials, such as grain and plastic particles, the required wind pressure is relatively low; while for some heavy and viscous materials, such as cement and coal powder, the required wind pressure is relatively high. In long-distance pneumatic conveying, due to the large pipeline resistance, the Roots blower is also required to provide a higher wind pressure to ensure that the material can be smoothly transported to the destination.
(III) Speed: Factors affecting functional efficiency
Speed refers to the rotation speed of the Roots blower impeller, usually measured in revolutions per minute (rpm). Speed is one of the core parameters that affect the performance of Roots blowers, and it is closely related to air volume and air pressure. Within a certain range, the higher the speed of the Roots blower, the greater the air volume, because the increase in speed allows the impeller to inhale and exhaust more gas per unit time. For example, when the speed of the Roots blower increases from 1000rpm to 1500rpm, its air volume may increase by about 50% accordingly. The specific increase will be affected by factors such as the structure and size of the blower and the properties of the gas.
At the same time, changes in speed will also affect the wind pressure. Generally speaking, as the speed increases, the wind pressure of the fan will also increase, because higher speeds increase the force of the impeller on the gas, thereby generating higher pressure. However, this relationship is not a simple linear relationship. When the speed exceeds a certain range, the growth rate of wind pressure may gradually slow down, and may even decrease due to the mechanical performance limitations of the blower. In addition, too high a speed will also lead to problems such as increased energy consumption, increased noise, and increased equipment wear of the blower, thereby affecting the service life and operating stability of the blower.
The speed has a profound impact on the overall function of the Roots blower. During the aeration process of sewage treatment, if the aeration volume needs to be increased to improve the sewage treatment efficiency, a feasible method is to appropriately increase the speed of the Roots blower, thereby increasing the air volume and providing more oxygen for the microorganisms in the aeration tank. However, when adjusting the speed, the various performance indicators and operating conditions of the blower must be fully considered to ensure that the increase in speed will not cause excessive burden on the blower and avoid equipment failure or performance degradation. In the pneumatic conveying system, the selection of speed also needs to be comprehensively considered based on factors such as the characteristics of the material, the conveying distance and the resistance of the pipeline to ensure that the blower can operate in an efficient and stable state and achieve smooth material transportation.
(IV) Motor power: source of power indicator
Motor power refers to the power of the motor required to drive the Roots blower, usually in kilowatts (kW) or horsepower (HP). As the power source of the Roots blower, the size of the motor power directly determines the driving force that the blower can obtain, which in turn affects the operating performance of the blower. The motor power is closely related to the parameters of the blower, such as air volume, air pressure and speed. Under the same working conditions, the larger the air volume and the higher the air pressure of the fan, the greater the motor power required. This is because a larger air volume and higher air pressure mean that the fan needs to overcome greater resistance and transport more gas, which requires stronger power support. For example, a Roots blower used in a large sewage treatment plant may be equipped with a motor power of several hundred kilowatts because it needs to provide a large amount of air volume and high air pressure to meet the needs of the aeration tank; while a small Roots blower used for ventilation in a small workshop may only have a motor power of a few kilowatts due to the lower air volume and air pressure requirements.
The change in speed will also have a significant impact on the motor power. When the speed of the fan increases, the motor needs to output a larger torque to drive the impeller to rotate, resulting in an increase in the motor power. According to the relationship between power and speed: P = T × n / 9550 (where P is power, T is torque, and n is speed), it can be seen that when the torque remains unchanged, the increase in speed will cause the power to increase linearly. Therefore, when adjusting the speed of the Roots blower, it is necessary to consider whether the power of the motor can meet the requirements to avoid motor overload. If the motor power is insufficient, forcibly increasing the speed of the blower may cause the motor to heat up, burn, or even damage other parts of the blower.
In the selection and use of Roots blowers, motor power is a crucial indicator. Correctly selecting a motor with the right power can not only ensure that the blower can operate stably and efficiently under various working conditions, but also avoid energy waste and equipment damage. If the motor power is too small, the blower may not meet the expected air volume and air pressure requirements, affecting production efficiency; if the motor power is too large, although it can meet the operating requirements of the blower, it will cause energy waste and increase operating costs. Therefore, when selecting, it is necessary to accurately calculate the required motor power and select the appropriate motor model and specifications based on the specific application scenario of the blower, air volume and pressure requirements, and speed and other parameters. During use, it is also necessary to pay close attention to the operating status of the motor to ensure that its power output matches the actual needs of the blower, and to promptly discover and solve possible power abnormalities.
(V) Other parameters supplement
Efficiency: The efficiency of Roots blower refers to its energy conversion efficiency in actual operation, usually expressed in percentage. The efficiency directly reflects the ability of the blower to convert the input electrical energy into gas mechanical energy, which has an important impact on the energy consumption and operating cost of the blower. A high-efficiency Roots blower can achieve the same gas delivery task while consuming less electrical energy, thereby reducing the energy consumption and production costs of the enterprise. In industrial production, improving the efficiency of the blower not only helps to save energy and reduce emissions, but also improves the economic benefits and competitiveness of the enterprise. For example, by optimizing the impeller design of the blower, improving the manufacturing process accuracy, and reasonably selecting lubrication and sealing materials, the efficiency of the blower can be effectively improved and energy loss can be reduced.
Noise: Noise is the sound intensity generated by the Roots blower during operation, measured in decibels (dB). In practical applications, the noise level is a parameter that cannot be ignored, which directly affects the comfort of the working environment and the health of the operator. When the Roots blower is working, it will generate a certain amount of noise due to the high-speed rotation of the impeller, the compression and flow of gas, and the friction of mechanical parts. If the noise is too loud, it will not only cause noise pollution to the surrounding environment and interfere with the normal communication and work of the staff, but long-term exposure to high-noise environments may also lead to health problems such as hearing loss. In order to reduce the noise of the Roots blower, a series of measures are usually taken, such as installing mufflers at the inlet and outlet of the blower, optimizing the structural design of the blower to reduce airflow pulsation, and using sound insulation materials to encapsulate the blower. These measures can effectively reduce the noise level, make the operation of the blower quieter and more environmentally friendly, and create a good working environment for the staff.
Casing type: The casing of the Roots blower usually adopts a horizontal split type, which is convenient for the installation and maintenance of the blower. In actual industrial production, the blower may have various faults after long-term operation, which requires inspection and maintenance. The horizontally split casing type allows maintenance personnel to easily open the casing to inspect, repair and replace the internal impeller, gears, bearings and other components, greatly improving maintenance efficiency, reducing downtime and reducing equipment maintenance costs. The casing is usually made of cast iron or welded steel plates. Cast iron has good casting and shock absorption properties, which can effectively reduce vibration and noise during the operation of the fan; the casing welded by steel plates has high strength and sealing, can withstand large gas pressure, and is suitable for some occasions with high pressure requirements.
Impeller type: As the core component of the Roots blower, the impeller type has a vital impact on the performance of the blower. At present, the common impeller types on the market are mainly three-leaf and two-leaf. Due to its special structural design, the three-leaf impeller can make the gas more evenly compressed and transported during operation. Compared with the two-leaf impeller, it has the advantages of smaller gas pulsation, lower noise and smoother operation. Therefore, the three-leaf impeller has gradually become the mainstream choice of Roots blowers. The material of the impeller is usually cast iron or cast steel. Cast iron has the advantages of low cost and good casting performance, but is relatively weak in strength and wear resistance. Cast steel has higher strength and wear resistance, can withstand greater impact and friction, and is suitable for some occasions with higher requirements on impeller performance, such as conveying high-hardness granular materials or Roots blowers operating under harsh working conditions.
Bearing type: The bearing is an important component that supports the rotation of the impeller in the Roots blower. The choice of its type is directly related to the smooth operation and service life of the blower. The bearings of Roots blowers usually use rolling bearings or sliding bearings. Rolling bearings have the advantages of low friction coefficient, low starting resistance, high efficiency, easy installation and maintenance, etc. They can maintain good performance under high-speed rotation and are suitable for most Roots blowers. Sliding bearings have the advantages of large load capacity, smooth operation, and low noise. They can play a good role under heavy load and low speed conditions, but the manufacturing and installation precision requirements of sliding bearings are high, and the maintenance cost is relatively high. They are generally used in some large Roots blowers with extremely high requirements for running stability. The bearings are usually lubricated by grease or oil bath. Grease lubrication has the advantages of easy use, good sealing performance, and low leakage. It is suitable for some small Roots blowers or blowers running in dusty environments. Oil bath lubrication can provide better lubrication effect to ensure the normal operation of bearings under high speed and heavy load. However, oil bath lubrication requires a special oil tank and lubrication system, and the structure is relatively complex. It is suitable for large Roots blowers or occasions with high lubrication requirements.
Sealing type: The inlet and outlet and bearings of Roots blowers are usually sealed by labyrinth seals or packing seals to improve the sealing performance and service life of the blower. Labyrinth seal is a way to achieve sealing by using the resistance generated by the flow of fluid in a tortuous channel. It has the advantages of simple structure, good sealing performance, long service life, etc. It can effectively prevent gas leakage and is suitable for most Roots blowers. The packing seal achieves the purpose of sealing by filling the sealing part with soft sealing materials, such as asbestos, graphite, etc. It has the advantages of reliable sealing performance, easy installation and replacement, etc. However, the packing seal may wear and age after long-term use and needs to be replaced regularly. It is generally used in some occasions where the sealing requirements are not particularly high. Good sealing performance can ensure the working efficiency of the fan, reduce energy waste, and prevent gas leakage from polluting the environment and harming the health of operators.
IV. The core functions of Roots blowers: gas delivery and pressurization
In the industrial field, Roots blowers play an extremely critical role. Their core functions - gas delivery and pressurization, like a powerful "engine" for industrial operation, provide indispensable support for many production processes. These two functions are closely related, but each has its own unique principles and application characteristics. Next, let us deeply analyze the two core functions of Roots blowers and explore their mysteries and values in industrial production.
(I) Detailed description of gas delivery function
1. In-depth explanation of the delivery principle
The gas delivery principle of Roots blowers is based on its unique working mechanism, which is closely related to the precise structural design inside the blower. As mentioned above, Roots blowers are mainly composed of key components such as casing, impeller, motor, and transmission device. When the blower is running, the motor, as a power source, drives the driving shaft to rotate at high speed through the transmission device, and then drives the driving impeller to rotate synchronously. At the same time, the driving shaft uses a pair of synchronous gears to make the driven impeller rotate at the same speed and in the opposite direction as the driving impeller.
During the rotation of the impeller, the gas delivery process begins quietly. Due to the carefully designed small gaps between the impellers, the impellers and the casing, and the impellers and the wall panels, when the impellers start to rotate, a vacuum state will quickly form at the air inlet. Under the strong effect of atmospheric pressure, air or other gases are smoothly sucked into the air inlet cavity. With the continuous and stable rotation of the impeller, two blades of each impeller, the wall panel and the casing cleverly form a sealed cavity, and the gas in the air inlet cavity is steadily brought to the exhaust cavity by the sealed cavity formed by the two blades. In the exhaust cavity, the impellers mesh with each other, like a tacitly coordinated "porter", accurately squeezing out the gas between the two blades so that it can be discharged smoothly from the exhaust port. In this way, the Roots blower realizes the continuous and efficient intake, compression and discharge of gas, and continuously delivers the required gas for industrial production.
In order to understand this process more vividly, we can compare the gas delivery process of the Roots blower to a chain drive. In chain transmission, the links on the chain are like the sealed chambers between the impellers of the Roots blower, which transfer items from one position to another in turn during the movement. The impeller of the Roots blower makes the sealed chamber circulate continuously between the air inlet and the exhaust port through relative movement, thereby realizing the continuous delivery of gas. However, unlike the chain transmission, the gap between the impellers of the Roots blower needs to be strictly controlled during the gas delivery process to ensure the sealing and delivery efficiency of the gas. If the gap is too large, the gas will leak during the delivery process, resulting in insufficient air volume and affecting the normal operation of the blower; if the gap is too small, the impeller may rub and collide when rotating at high speed, damaging the blower components and reducing the service life of the blower.
2. Analysis of the characteristics of different gas delivery
In actual applications, Roots blowers need to deliver a variety of gases. The physical and chemical properties of different gases are different, which leads to different functional performances and precautions when Roots blowers deliver different gases.
When delivering clean air, Roots blowers can operate stably and efficiently, giving full play to their design performance. The composition of clean air is relatively simple, with fewer impurities, and will not cause corrosion and wear to the impeller, casing and other parts inside the fan. In general ventilation occasions, such as the ventilation system of buildings and air conditioning in workshops, Roots blowers can easily deliver clean air to designated locations, creating a comfortable and healthy working and living environment for people.
However, when it comes to the transportation of flammable and explosive gases, the situation becomes much more complicated. Flammable and explosive gases, such as coal gas and biogas, are extremely dangerous. Once a leak occurs and encounters a fire source, it may cause an explosion accident, causing serious casualties and property losses. Therefore, when using Roots blowers to transport flammable and explosive gases, a series of strict safety measures must be taken. The motor of the fan must be an explosion-proof motor to prevent the motor from generating electric sparks during operation and causing gas explosions. The sealing performance of the fan must meet extremely high standards, and special sealing structures and materials, such as labyrinth seals and mechanical seals, are used to ensure that the gas does not leak. Safety devices such as flame arresters need to be installed on the inlet and outlet pipes of the fan to prevent the spread of flames and prevent the expansion of explosion accidents. Before using the fan, operators must receive professional safety training, be familiar with the characteristics and safe operating procedures of flammable and explosive gases, and operate strictly in accordance with the regulations to avoid safety accidents caused by improper operation.
For some corrosive gases, such as sulfur dioxide and chlorine, the internal parts of the Roots blower will be strongly corroded during the transportation process. In order to meet this challenge, the flow-through part of the fan, that is, the parts that are in direct contact with the gas, such as impellers, casings, wall panels, etc., need to be made of corrosion-resistant materials, such as stainless steel and titanium alloys. These materials have good corrosion resistance and can work stably for a long time in a corrosive gas environment to ensure the normal operation of the fan. It is also necessary to regularly maintain and service the fan, check the corrosion of the parts, and replace the damaged parts in time to extend the service life of the fan.
When conveying high-temperature gas, the Roots blower faces the problem of thermal expansion and the influence of high temperature on material properties. High-temperature gas may cause thermal expansion of fan components, resulting in a smaller gap between the impeller and the casing and wallboard, which may cause friction and collision between components. High temperature may also reduce the strength and hardness of the material, affecting the normal operation of the fan. Therefore, when conveying high-temperature gas, the fan needs to be specially designed and modified. Use high-temperature resistant materials to manufacture fan components, and reasonably design the fan's cooling system, such as adding heat sinks, using water cooling or air cooling, to dissipate heat in time and ensure that the fan can operate stably in a high-temperature environment.
(II) Analysis of gas boosting function
1. Boosting principle and process display
The gas boosting function of Roots blower is another core capability of Roots blower, which plays a vital role in many industrial fields. The boosting principle of Roots blower is also based on its unique structure and working mode. When the blower is running, the motor drives the impeller to rotate at high speed through the transmission device. During the rotation of the impeller, the gas is sucked in from the air inlet. As the impeller rotates, the gas is gradually compressed and pushed to the exhaust port. In this process, due to the extremely small gaps between the impeller and the impeller, the impeller and the casing, and the impeller and the wallboard, the gas gradually decreases in volume and increases in pressure during the squeezing process, thereby achieving gas boosting.
Specifically, when the gas enters the air inlet chamber of the Roots blower, it will be surrounded by the blades of the impeller to form sealed air chambers. As the impeller rotates, the gas in these air chambers is gradually pushed to the exhaust chamber. At the exhaust chamber, the meshing action of the impeller causes the gas in the air chamber to be further compressed, the pressure is further increased, and finally discharged from the exhaust port. In this process, factors such as the fan speed, the shape and size of the impeller, and the gas flow rate will have a significant impact on the supercharging effect. A higher speed can enable the impeller to compress the gas more times per unit time, thereby improving the supercharging effect; a reasonably designed impeller shape and size can better guide the gas flow, reduce energy loss, and improve supercharging efficiency; a stable gas flow rate can ensure that the fan works in a continuous and stable state, ensuring the consistency of the supercharging effect.
In order to more intuitively understand the supercharging process of the Roots blower, we can compare it to the working process of a piston compressor. In a piston compressor, the piston reciprocates in the cylinder, and the gas pressure in the cylinder is increased through the compression of the piston. The impeller of the Roots blower is equivalent to the piston in the piston compressor. Through the rotation of the impeller, the gas is compressed to achieve gas supercharging. However, the supercharging process of the Roots blower is continuous, while the supercharging process of the piston compressor is intermittent. During the boosting process of the Roots blower, the pressure change of the gas is relatively stable, while during the boosting process of the piston compressor, the pressure of the gas will fluctuate periodically.
2. List of application scenarios of the boosting function
The gas boosting function of the Roots blower has a wide range of application scenarios in industry and life, and it provides necessary support for many production processes and life needs.
In the industrial field, sewage treatment plants are one of the important application places for the boosting function of the Roots blower. During the sewage treatment process, a large amount of air needs to be introduced into the aeration tank to meet the demand of microorganisms for oxygen and promote the decomposition of organic matter in sewage. Through its boosting function, the Roots blower compresses the air and transports it to the aeration tank to provide sufficient oxygen for the microorganisms. Due to the large water depth in the aeration tank, the gas needs to overcome a certain water pressure to reach the water surface, so the Roots blower needs to provide sufficient pressure to ensure that the air can be smoothly transported to the aeration tank and improve the sewage treatment efficiency.
In the pneumatic conveying system, the boosting function of the Roots blower also plays a key role. Pneumatic conveying is a way of transporting materials through pipelines using the energy of gas. It is widely used in the transportation of materials such as grain, cement, and chemical raw materials. Roots blowers pressurize the gas so that the gas has enough energy to drive the material to flow in the pipeline, thereby achieving efficient material transportation. In long-distance pneumatic transportation, due to the large pipeline resistance, Roots blowers are required to provide higher pressure to ensure that the material can be smoothly transported to the destination. In some large cement plants, Roots blowers transport compressed air to cement silos and use high-pressure gas to transport cement to a distant place through pipelines, thereby achieving efficient transportation of cement, greatly improving production efficiency and reducing transportation costs.
In chemical production, many chemical reactions need to be carried out under certain pressure conditions. The boosting function of Roots blowers can provide the required gas pressure for these reactions. In the process of synthetic ammonia production, hydrogen and nitrogen need to be compressed to a certain pressure and then sent into the synthesis tower to synthesize ammonia under the action of a catalyst. Roots blowers pressurize hydrogen and nitrogen and transport them to the synthesis tower, providing the necessary conditions for the synthetic ammonia reaction. In the production process of some chemical products, high-pressure gas is also needed for stirring, mixing and separation of materials. The boosting function of Roots blowers can meet these process requirements and ensure the smooth progress of chemical production.
In the field of life, the boosting function of Roots blowers also has important applications. In the water supply systems of some high-rise buildings, due to the high floors and insufficient water pressure, boosting equipment is needed to increase the water pressure to ensure that residents can use water normally. Roots blowers can pressurize the air, inject compressed air into the water supply system, and use the pressure of the air to transport water to high-rise residents, solving the problem of difficult water supply in high-rise buildings. In some fire protection systems, Roots blowers are also needed to pressurize the air to provide high-pressure gas for fire hoses, enhance the fire extinguishing effect, and protect people's lives and property.
V. Functional display in various fields: multiple applications
(I) Sewage treatment field
In the field of sewage treatment, Roots blowers are well-deserved "behind-the-scenes heroes" and play an extremely critical and indispensable role. Sewage treatment is a complex and systematic project. Its core goal is to decompose and remove harmful substances in sewage to meet emission standards, thereby protecting water resources and the ecological environment. In this process, Roots blowers mainly undertake the important tasks of providing oxygen to microorganisms and stirring sewage. These functions play a decisive role in improving the sewage treatment effect.
Providing oxygen to microorganisms is one of the core functions of Roots blowers in sewage treatment. In the aeration tank of the sewage treatment plant, there are a large number of microorganisms. They are like hardworking "cleaners". Through their own metabolic activities, they decompose organic matter in sewage into harmless substances such as carbon dioxide and water. However, the survival and work of these microorganisms cannot be separated from the support of oxygen, just as humans need to breathe air. Roots blowers provide sufficient oxygen for microorganisms by compressing air and transporting it to the aeration tank, ensuring that they can efficiently decompose organic matter in sewage in an aerobic environment. For example, in the activated sludge sewage treatment process, Roots blowers continuously inject air into the aeration tank, so that the aerobic microorganisms in the activated sludge can fully contact oxygen, thereby accelerating the degradation of organic matter in the sewage. Studies have shown that under appropriate aeration conditions, the efficiency of microbial decomposition of organic matter can be increased by 30% - 50%, which fully demonstrates the importance of Roots blowers in providing oxygen to microorganisms.
In addition to providing oxygen, Roots blowers can also stir sewage, and this function should not be underestimated. In the aeration tank, sewage needs to maintain a certain fluidity to ensure that microorganisms can be evenly distributed in the sewage and fully contact the organic matter and oxygen in the sewage. The airflow generated by the Roots blower can stir the sewage, so that various substances in the sewage are fully mixed to avoid sedimentation and stratification. In some large sewage treatment plants, the aeration tank area is large. If there is no effective stirring measure, the suspended matter in the sewage may settle at the bottom, resulting in a decrease in treatment effect. The Roots blower can keep the suspended matter in the sewage in a suspended state through the powerful airflow stirring effect, increase the contact opportunity between microorganisms and pollutants, and thus enhance the sewage treatment effect. Stirring can also promote the uniform distribution of dissolved oxygen in sewage, avoid local hypoxia, and further ensure the normal metabolic activities of microorganisms.
Roots blowers improve the sewage treatment effect in an all-round way. By providing sufficient oxygen for microorganisms and effectively stirring sewage, Roots blowers can significantly improve the decomposition efficiency of organic matter in sewage, reduce the chemical oxygen demand (COD) and biochemical oxygen demand (BOD) in sewage, and purify sewage. In some urban sewage treatment plants, after aeration and stirring with Roots blowers, the COD removal rate of sewage can reach more than 80%, the BOD removal rate can reach more than 90%, and the effluent water quality can stably meet the national emission standards. Roots blowers can also promote the removal of nutrients such as nitrogen and phosphorus in sewage and reduce the risk of eutrophication of water bodies. In some sewage treatment plants that use biological denitrification and phosphorus removal processes, Roots blowers can provide a suitable living environment for denitrifying bacteria and polyphosphate bacteria by reasonably controlling the aeration time and intensity, thereby achieving effective removal of nitrogen and phosphorus in sewage.
(II) Pneumatic conveying field
In the field of pneumatic conveying, Roots blowers have become ideal equipment for conveying powdered and granular materials with their unique performance advantages. They are widely used in industries such as grain, cement, and chemical raw materials, providing strong support for the efficient production of these industries.
Roots blowers have many significant functional advantages when conveying powdered and granular materials. They can generate stable airflow and provide strong power for the conveying of materials. In the pneumatic conveying system, Roots blowers compress the air and inject it into the pipeline to form a high-speed airflow. The materials are carried by the airflow and transported to the designated location along the pipeline. This conveying method has the characteristics of high conveying efficiency and long conveying distance, which can meet the needs of different production scenarios. In the grain processing industry, Roots blowers can transport grain from the warehouse to the processing workshop. The conveying distance can reach hundreds of meters and the conveying volume can reach tens of tons per hour, which greatly improves the conveying efficiency of grain and reduces the workload of manual handling.
The conveying process of Roots blowers is relatively gentle, which can effectively reduce the damage of materials. For some fragile materials, such as food and medicine, traditional mechanical conveying methods may cause the materials to be squeezed, rubbed and damaged during the conveying process, affecting the product quality. Roots blowers convey materials through airflow, and the materials are suspended in the pipeline, with less contact with the inner wall of the pipeline, thereby reducing the breakage rate of the materials. In the food processing industry, when using Roots blowers to convey powdered materials such as flour, the flour particles can be ensured to be intact, and the phenomenon of crushing and agglomeration can be avoided, thus ensuring the processing quality of the food.
Roots blowers also have good sealing properties, which can prevent material leakage and the mixing of external impurities. During the pneumatic conveying process, if the material leaks, it will not only cause material waste, but also may cause environmental pollution. Roots blowers use special sealing structures, such as labyrinth seals and mechanical seals, which can effectively prevent material leakage and ensure the safety and environmental protection of the conveying process. The air inlet of the Roots blower is usually equipped with a filter, which can filter out impurities in the air, prevent impurities from mixing into the material, and ensure the purity of the material.
In order to more intuitively understand the application effect of Roots blowers in the field of pneumatic conveying, let's look at some actual application cases. In a large cement plant, Roots blowers are used as pneumatic conveying equipment to transport cement from the production workshop to the storage warehouse. The cement plant has a large production scale and needs to transport a large amount of cement every day. After using Roots blowers, the cement conveying efficiency has been significantly improved, and the daily conveying volume has increased from hundreds of tons to thousands of tons. The stable operation of Roots blowers also ensures the continuity of cement conveying and reduces production interruptions caused by equipment failure. Due to the good sealing of Roots blowers, cement leakage during transportation is avoided, environmental pollution is reduced, and the labor intensity of workers is also reduced.
In a grain reserve warehouse, in order to achieve efficient grain transportation, a Roots blower pneumatic conveying system was installed. The system can directly transport grain from train carriages or cars to warehouses, realizing the automatic loading and unloading of grain. In the actual operation process, the Roots blower can automatically adjust the air volume and pressure according to the demand for conveying volume to ensure the conveying speed and quality of grain. By using the Roots blower pneumatic conveying system, the grain loading and unloading efficiency of the grain reserve warehouse has been increased several times, greatly shortening the grain loading and unloading time and reducing transportation costs. Moreover, due to the extremely low damage rate of grain during the conveying process of the Roots blower, the quality of grain is guaranteed, providing a strong guarantee for the storage and sale of grain.
(III) Cement Industry
In the cement industry, Roots blowers play a pivotal role. They provide power for cement production equipment and are an indispensable key equipment in the cement production process, which has a profound impact on cement production efficiency.
Cement production is a complex process involving multiple links such as raw material grinding, raw material preparation, clinker calcination, and cement grinding and packaging. In these links, many equipment require Roots blowers to provide power support to ensure the smooth progress of the production process. During the calcination process of the cement kiln, a large amount of air is required to provide the oxygen required for fuel combustion and to discharge the exhaust gas generated by combustion. Roots blowers provide sufficient oxygen for the full combustion of fuel by compressing air and delivering it to cement kilns, so that the temperature in the cement kiln can reach about 1450℃, ensuring the calcination quality of clinker. Roots blowers can also adjust the air flow distribution in the cement kiln, making the temperature and atmosphere in the kiln more uniform, which is conducive to improving the output and quality of clinker.
In cement grinding systems, Roots blowers also play an important role. Cement grinding is the process of grinding raw materials such as clinker and gypsum into cement, and qualified cement products need to be separated by air separation equipment. Roots blowers provide power for air separation equipment, so that the air flow circulates in the grinding system, blows up the ground cement particles and delivers them to the powder separator for separation. By adjusting the air volume and air pressure of the Roots blower, the powder separation efficiency of the powder separator and the particle grading of cement can be controlled, thereby producing cement products of different grades. In some large cement plants, by optimizing the operating parameters of Roots blowers, the output of cement grinding systems has increased by 10% - 20%, while reducing power consumption, improving production efficiency and economic benefits.
Roots blowers are also indispensable equipment in the pneumatic conveying link of cement production. In cement plants, various raw materials, semi-finished products and finished products need to be transported through pipelines, such as transporting raw materials such as limestone and clay from the yard to the raw material mill, transporting cement clinker from the cement kiln to the clinker warehouse, and transporting finished cement from the cement mill to the packaging workshop. Roots blowers generate stable airflows to transport materials in pipelines, realize the automatic transportation of materials, reduce the workload of manual handling, and improve production efficiency. Moreover, due to the good sealing of the conveying process of Roots blowers, it can avoid leakage and flying of materials during the conveying process, reducing pollution to the environment.
Roots blowers have many effects on cement production efficiency. It provides stable power for cement production equipment, ensures the normal operation of each production link, and avoids production interruptions caused by equipment failure. By adjusting the air volume and air pressure of the Roots blower, the production process parameters can be optimized, the operating efficiency of the equipment can be improved, and thus the output and quality of cement can be increased. In the calcination process of the cement kiln, the reasonable adjustment of the air volume of the Roots blower can make the fuel fully burn, increase the temperature in the kiln, and speed up the calcination of the clinker, thereby increasing the output of the cement kiln. In the cement grinding system, by adjusting the air volume and air pressure of the Roots blower, the powder selection efficiency of the powder classifier can be higher, the cement particles produced can be more uniform, and the quality of cement can be improved. The use of Roots blowers can also reduce production costs and improve the competitiveness of enterprises. Since Roots blowers can realize the automatic transportation of materials, the workload of manual handling is reduced, and the labor cost is reduced; at the same time, by optimizing the production process, the operating efficiency of the equipment is improved, the energy consumption is reduced, and the production cost is further reduced.
(IV) Aquaculture Field
In the field of aquaculture, Roots blowers, as a highly efficient oxygenation equipment, have made important contributions to the development of aquaculture. It provides good conditions for the growth and reproduction of aquatic organisms by increasing the dissolved oxygen content in the water and improving the breeding environment, and plays a key role in increasing aquaculture production.
The dissolved oxygen content in the water is a crucial indicator in aquaculture, which directly affects the survival and growth of aquatic organisms. When the dissolved oxygen content in the water is insufficient, aquatic organisms will have breathing difficulties, slow growth, decreased immunity, and even death. Roots blowers compress and transport air into the water to form tiny bubbles, which increases the contact area between the water and the air, allowing the oxygen in the air to dissolve into the water faster, thereby increasing the dissolved oxygen content in the water. In some high-density fish ponds, due to the high breeding density, the respiration of aquatic organisms and the decomposition of organic matter will consume a lot of oxygen, which can easily lead to hypoxia in the water. After using Roots blowers to increase oxygen, the dissolved oxygen content in the water can be effectively increased to ensure the normal growth of aquatic organisms. Studies have shown that when the dissolved oxygen content of water increases from 4mg/L to 6mg/L, the growth rate of fish can be increased by 20% - 30%, and the feed utilization rate can also be increased by 10% - 20%.
In addition to increasing the dissolved oxygen content of water, Roots blowers can also improve the breeding environment. In breeding water, due to the accumulation of organic matter such as metabolites of aquatic organisms and residual bait, the content of harmful substances in the water will increase, such as ammonia nitrogen, nitrite, etc. These substances are toxic to aquatic organisms. During the oxygenation process of Roots blowers, the flow and circulation of water can be promoted, so that harmful substances in the water can be decomposed and transformed faster, the concentration of harmful substances can be reduced, and the breeding environment can be improved. Oxygenation can also inhibit the growth and reproduction of harmful microorganisms, reduce the occurrence of diseases, and improve the survival rate of aquatic organisms. In some shrimp ponds, after using Roots blowers for oxygenation, the ammonia nitrogen content in the water was significantly reduced, the incidence of shrimp was reduced by 30% - 50%, and the survival rate was increased by 20% - 30%.
The help of Roots blowers to aquaculture production is obvious. By increasing the dissolved oxygen content in the water and improving the aquaculture environment, Roots blowers provide more suitable living and growth conditions for aquatic organisms, promote the growth and reproduction of aquatic organisms, and thus increase aquaculture production. In some farms that use Roots blowers for oxygenation, the aquaculture production of fish can be increased by 30% - 50%, and the aquaculture production of shrimp can be increased by 50% - 100%. Moreover, because aquatic organisms grow in a good environment, their quality has also been improved, and the market price is higher, which further improves the economic benefits of farmers. For example, in a large perch farm, after using Roots blowers to increase oxygen, the growth rate of perch has been significantly accelerated, the breeding cycle has been shortened by 1-2 months, the output has increased by about 40%, and the meat of perch is more delicious. The market price is 20%-30% higher than that of ordinary perch, and the income of farmers has increased significantly.
(V) Food Industry
In the food industry, Roots blowers, with their unique functions, play an important role in food raw material transportation, packaging gas protection, etc., providing a strong guarantee for the safe production and preservation of food.
In the food raw material transportation link, Roots blowers show the advantages of efficient and hygienic transportation. There are many kinds of food raw materials, including powdered materials such as grains, flour, milk powder, and powdered sugar, as well as block or granular materials such as fruits, vegetables, and meat. Roots blowers can transport these raw materials in pipelines by generating stable airflow, realizing the automated transportation of raw materials and improving production efficiency. Since the conveying process of Roots blowers is relatively gentle, it can reduce the damage and contamination of raw materials during the conveying process, thus ensuring the quality of raw materials. In flour production enterprises, Roots blowers transport wheat from warehouses to milling workshops. During the conveying process, flour will not be subjected to excessive extrusion and friction, thus avoiding the breakage and heating of flour particles and ensuring the quality of flour. Roots blowers have good sealing properties, which can prevent external impurities from mixing into raw materials, thus ensuring the sanitation and safety of food raw materials.
In the process of food packaging, Roots blowers provide key support for packaging gas protection. In order to extend the shelf life of food, many foods need to be filled with protective gases, such as nitrogen and carbon dioxide, during packaging. These gases can remove oxygen from the package, inhibit the growth and reproduction of microorganisms, and prevent food from oxidizing and deteriorating. Roots blowers compress and convey the gas, fill the protective gas into the food packaging, forming an oxygen-free environment, which effectively extends the shelf life of the food. Nitrogen is usually filled into the packaging of snack foods such as potato chips and biscuits. After using Roots blowers to fill nitrogen into the packaging, potato chips and biscuits can be prevented from getting damp, softening and oxidizing, and their crisp taste and good color can be maintained. Roots blowers can also accurately control the amount of gas filled, ensure the stability of the pressure and composition of the gas in the package, and improve the quality and stability of food packaging.
The application of Roots blowers in the food industry not only improves the efficiency and quality of food production, but also ensures the safety and preservation of food. In the process of conveying food raw materials, the efficient conveying and hygienic protection functions of Roots blowers ensure that the raw materials can reach the production link in a timely and safe manner, providing sufficient raw material supply for food production. In the food packaging link, the gas protection function of Roots blowers effectively extends the shelf life of food, reduces food loss, and improves the market competitiveness of food. In some large food companies, by using Roots blowers for raw material conveying and packaging gas protection, the production efficiency of food has increased by 30% - 50%, and the shelf life of food has been extended by 1 - 2 times, greatly improving the economic and social benefits of the company.
(VI) Chemical and petrochemical fields
In the chemical and petrochemical fields, Roots blowers are like a shining star, playing an irreplaceable and important role in key links such as raw gas preparation and gas transportation, and becoming an important guarantee for the smooth progress of chemical production.
In the raw gas preparation link, Roots blowers bear the heavy responsibility of providing suitable gas raw materials for chemical reactions. In the chemical production process, many chemical reactions require specific gases as raw materials, such as hydrogen, nitrogen, oxygen, etc. Roots blowers compress and transport the gases, and transport these raw gases to the reaction device according to the pressure and flow required by the process, providing the necessary conditions for the smooth progress of chemical reactions. In the process of synthetic ammonia production, hydrogen and nitrogen need to be mixed in a certain proportion and sent to the synthesis tower to synthesize ammonia under high temperature, high pressure and catalyst. Roots blowers are responsible for compressing hydrogen and nitrogen to the required pressure and accurately controlling their flow and proportion to ensure that the synthetic ammonia reaction can be carried out efficiently and stably. If the pressure, flow or proportion of the raw gas deviates, it will affect the rate and yield of the chemical reaction, and even make the reaction impossible.
Roots blowers also play a key role in gas transportation. In chemical production, gases need to be transported between different equipment and processes, such as from raw material storage tanks to reaction devices, from reaction devices to separation equipment, and from separation equipment to storage tanks. With its stable performance and strong transportation capacity, Roots blowers can efficiently transport various gases in pipelines to meet the strict requirements of chemical production for gas transportation. In petrochemical production, various gases generated during crude oil processing, such as petroleum gas and natural gas, need to be transported to subsequent processing devices for further processing. Roots blowers can compress these gases to a suitable pressure, overcome pipeline resistance, and ensure that the gases can be smoothly transported to the destination. Moreover, since the gases transported in chemical production often have the characteristics of being flammable, explosive, toxic and harmful, the sealing performance and safety performance of Roots blowers are crucial. Roots blowers adopt special sealing structures and explosion-proof designs, which can effectively prevent gas leakage, avoid safety accidents, and ensure the safe progress of chemical production.
The importance of Roots blowers to chemical production is self-evident. Its stable operation in the raw gas preparation and gas transportation links is directly related to the continuity and stability of chemical production. If the Roots blower fails, it will cause the interruption of raw gas supply or poor gas transportation, making the chemical reaction unable to proceed normally and even causing production accidents. The performance of the Roots blower will also affect the efficiency and cost of chemical production. Efficient Roots blowers can improve the gas transportation efficiency and reduce energy consumption, thereby improving the efficiency of chemical production and reducing production costs. In some large chemical companies, by optimizing the selection and operation parameters of Roots blowers, the energy consumption of chemical production has been reduced by 10% - 20%, and the production efficiency has been increased by 15% - 30%, greatly improving the economic benefits and competitiveness of the company.
(VII) Power field
In the power field, Roots blowers play an indispensable role, playing an important role in key links such as coal powder combustion and pneumatic ash conveying, providing strong support for the stable operation of power production.
In the process of coal powder combustion, Roots blowers play a vital role. Thermal power generation is one of the main power generation methods at present. Its principle is to release heat energy by burning coal powder, heat water into high-temperature and high-pressure steam, drive the turbine to rotate, and then drive the generator to generate electricity. The full combustion of coal powder is inseparable from sufficient oxygen supply. Roots blower is the key equipment to provide oxygen for coal powder combustion. Roots blower compresses air and transports it to the burner of the boiler, fully mixing it with coal powder, so that the coal powder can be
VI. Advantages and limitations of Roots blower functions
(I) Advantages
Simple structure and convenient maintenance: The structure of Roots blower is relatively simple, mainly composed of basic components such as casing, impeller, motor, transmission device, etc. This simple structural design gives the blower significant advantages in installation, commissioning and daily maintenance. During the installation process, due to the relatively small number of components and the relatively direct connection method, the installation time can be greatly shortened, the installation difficulty can be reduced, and the hidden dangers of failure caused by improper installation can be reduced. During daily maintenance, maintenance personnel can easily inspect, clean and maintain each component, and quickly discover and solve potential problems. For example, when it is necessary to replace the impeller or bearing, due to the simple structure and large operating space, maintenance personnel can quickly complete the replacement work, effectively reducing the downtime of the equipment and improving production efficiency. Moreover, the simple structure also means less wear and failure points of parts, reducing maintenance costs and maintenance difficulties, making the Roots blower more reliable and longer in service life.
Stable delivery and constant flow: Roots blower has the characteristics of forced air delivery, which enables it to provide stable flow output when working. No matter how the system pressure changes, as long as it is within the design pressure range of the Roots blower, its output flow rate can remain relatively stable and is almost unaffected by exhaust pressure fluctuations. In the aeration system of the sewage treatment plant, a stable flow of air needs to be continuously delivered to the aeration tank to meet the oxygen needs of microorganisms. The Roots blower can accurately control the air flow rate, ensure the stability of the oxygen concentration in the aeration tank, provide a good living environment for microorganisms, and thus improve the sewage treatment effect. In the pneumatic conveying system, a stable flow rate is essential for the transportation of materials. The Roots blower can transport materials evenly and stably in the pipeline, avoid material accumulation or blockage, and ensure the continuity and stability of the production process.
Widely applicable and highly compatible: The Roots blower has a very wide range of applications and can adapt to the transportation needs of various gases of different properties. Whether it is clean air, flammable and explosive gases, or corrosive gases, as long as appropriate protective measures are taken, the Roots blower can do it. In the chemical industry, it is often necessary to transport gases of various properties such as hydrogen, nitrogen, and chlorine. Roots blowers can safely and stably transport these gases by using special sealing materials, explosion-proof motors, and corrosion-resistant impellers to meet the process requirements of chemical production. In many industries such as sewage treatment, aquaculture, electricity, and food, Roots blowers also play an important role with their wide applicability, providing reliable gas transportation guarantees for the production of various industries.
Efficient and energy-saving, economical and practical: With the continuous advancement of technology, modern Roots blowers pay more and more attention to the improvement of energy-saving performance in the design and manufacturing process. By optimizing the impeller design, improving the transmission device, and adopting efficient motors, Roots blowers can achieve a large amount of gas transportation with lower energy consumption, effectively reducing the operating costs of enterprises. Some new Roots blowers use advanced energy-saving technologies, such as variable frequency speed regulation technology, which can automatically adjust the speed of the blower according to the actual working conditions, thereby achieving more accurate flow control and energy consumption optimization. In some industries with high energy consumption requirements, such as electricity and chemical industry, this high-efficiency and energy-saving Roots blower can save a lot of energy costs for enterprises and improve the economic benefits of enterprises. Moreover, the price of Roots blower is relatively reasonable, achieving a good balance between performance and cost, and has a high cost performance, making it one of the preferred choices for many companies when selecting gas conveying equipment.
Smooth operation and low noise: During the operation of Roots blower, due to the reasonable design of the gap between the impeller and the impeller and the casing and wallboard, and the use of advanced dynamic balancing technology and noise reduction measures, the operation of the blower is very stable and the noise generated is low. In some occasions with high requirements for the working environment, such as food processing workshops and hospitals, low-noise Roots blowers can create a relatively quiet and comfortable working environment for staff, reducing the impact of noise on the physical and mental health of staff. Smooth operation also helps to extend the service life of the blower and reduce the wear and tear of the equipment and the probability of failure. For example, some Roots blowers with three-blade impeller design have smaller air pulsation, smoother operation and lower noise than traditional two-blade impeller blowers, which can better meet various application scenarios with high requirements for running stability and noise.
Long life and high reliability: The structural design of Roots blowers is reasonable, the matching precision between parts is high, and high-quality materials are used for manufacturing, which makes the blowers have a long service life and high reliability. Under normal use and maintenance conditions, Roots blowers can operate stably for a long time, reduce equipment failures and downtime, and provide reliable protection for the production of enterprises. In some large industrial production enterprises, Roots blowers are key gas conveying equipment, and their reliability directly affects the continuity of the entire production process. Because Roots blowers have high reliability and can operate stably under harsh working conditions, they have been widely used. Moreover, the maintenance of Roots blowers is relatively simple. Only regular inspection, cleaning and replacement of wearing parts and other routine maintenance work can ensure the normal operation of the blower, further improving its service life and reliability.
(II) Limitation Analysis
Pressure is limited, high pressure is insufficient: The working principle and impeller structure of Roots blower determine that it has certain limitations in output pressure. Usually, its outlet pressure is relatively low. This is because as the pressure increases, the amount of gas leakage inside the blower will gradually increase, resulting in a decrease in the efficiency of the blower, and may even fail to work properly. In some industrial application scenarios with high pressure requirements, such as high-pressure gas transportation and high-pressure chemical reactions, Roots blowers may not be able to meet the needs. In the petrochemical industry, some processes require the gas to be compressed to extremely high pressure to achieve specific chemical reactions or material transportation. At this time, Roots blowers are unable to cope with it, and other types of high-pressure blowers, such as screw compressors and reciprocating compressors, need to be selected. In order to break through the pressure limit to a certain extent, some Roots blowers adopt a two-stage series design, which increases the output pressure of the gas by sequentially compressing the two-stage impeller, but this method will also increase the cost and complexity of the equipment, and the pressure increase is still limited.
Energy consumption is high and efficiency needs to be improved: Although modern Roots blowers have made some progress in energy saving, their energy consumption is still relatively high compared with some new high-efficiency blowers. This is mainly because during the operation of the Roots blower, the gas compression is achieved through the mechanical squeezing of the impeller. This compression method has a large energy loss, resulting in a relatively low efficiency of the blower. With the increasing energy costs today, higher energy consumption will undoubtedly increase the operating costs of enterprises and reduce their competitiveness. In some large-scale industrial production, such as cement production and steel smelting, a large amount of gas transportation requires a lot of electricity. If Roots blowers with high energy consumption are used, the electricity bill of the enterprise will increase significantly. In order to reduce energy consumption and improve efficiency, enterprises can take some measures, such as frequency conversion transformation of Roots blowers, adjusting the speed of the blowers in real time according to actual working conditions, and avoiding the operation of the blowers under unnecessary high loads; they can also regularly maintain the blowers to ensure that all parts of the blowers are in good working condition and reduce energy losses.
Noise troubles, environmental impact: Although Roots blowers have made great improvements in running smoothness and noise control, under certain working conditions, the noise they generate may still have a certain impact on the surrounding environment. The noise of Roots blowers mainly comes from the high-speed rotation of the impeller, the compression and flow of gas, and the friction of mechanical parts. In some occasions with strict noise requirements, such as factories near residential areas, schools, hospitals, etc., excessive noise may cause complaints from residents and affect the normal production of enterprises. In order to reduce the impact of noise on the environment, a series of noise reduction measures are usually taken, such as installing mufflers at the inlet and outlet of the fan, using the sound-absorbing materials and special structures inside the muffler to absorb and attenuate the noise generated by the gas flow; setting up a soundproof cover for the fan, enclosing the fan in a soundproof space, and reducing the spread of noise; optimizing the structural design of the fan, using advanced dynamic balancing technology to reduce the vibration and noise when the impeller rotates.
Volume and weight, installation challenges: Compared with some small and compact fans, Roots blowers are larger in size and heavier in weight, which to a certain extent increases the difficulty of their installation and transportation. During the installation process, it is necessary to provide sufficient installation space and a solid foundation for the Roots blower to ensure that the blower can operate stably. If the installation space is limited or the foundation is not solid, it may cause difficulty in installing the blower and even affect the normal operation of the blower. In some workshops or construction sites with narrow space, large Roots blowers may not be installed smoothly, and the site needs to be modified or a special installation method is required. The weight of the Roots blower is large, and professional transportation equipment is required during transportation, which increases transportation costs and transportation risks. In order to solve the problems caused by volume and weight, some manufacturers have introduced compact Roots blower designs. Under the premise of ensuring the performance of the blower, the volume and weight of the blower are minimized to improve its installation and transportation convenience.
Media sensitive, protection necessary: Roots blowers are sensitive to the properties of the conveying medium. If the conveyed gas contains a large amount of dust, particulate matter or is corrosive, it may cause wear and corrosion to the internal components of the blower, thereby affecting the performance and service life of the blower. In the cement industry, pneumatically conveyed cement powder often contains a certain amount of dust and particles. When these substances pass through the Roots blower, they will rub against the impeller, casing and other parts of the blower, causing increased wear of the parts and shortening the service life of the blower. In the chemical industry, when conveying corrosive gases, if the protection measures of the blower are not in place, the metal parts of the blower will be corroded, reducing the strength and sealing of the blower, causing safety accidents. In order to deal with these problems, it is necessary to pre-treat the conveyed medium, such as installing filters to remove dust and particles in the gas; the internal parts of the blower are made of corrosion-resistant materials or undergo special anti-corrosion treatment; the blower is regularly inspected and maintained, and damaged parts are replaced in time to ensure the normal operation of the blower.
Starting characteristics, current shock: When the Roots blower is started, the motor needs to overcome the inertia of the blower impeller and the resistance of the system, so the starting current is usually large, which can reach 5-7 times the rated current. This large starting current will cause a certain impact on the power grid and may affect the normal operation of other equipment in the power grid. In some areas where electricity supply is tight or grid stability is required to be high, excessive starting current may cause grid voltage fluctuations and affect the normal operation of other electrical equipment. In order to reduce the impact of starting current on the grid, some starting methods are usually adopted, such as star-delta starting, auto-coupling step-down starting, and variable frequency starting. Star-delta starting reduces the starting current by connecting the motor windings into a star shape at startup, and then switches to a triangle connection after the motor speed increases to enable the motor to operate normally; auto-coupling step-down starting uses an autotransformer to reduce the starting voltage of the motor, thereby reducing the starting current; variable frequency starting adjusts the power supply frequency of the motor through the inverter to achieve smooth starting of the motor, effectively reducing the starting current, and can also accurately control the motor speed according to the actual working conditions, thereby improving the operating efficiency and energy saving effect of the fan.
VII. Maintenance and care: ensuring stable functions
(I) Key points of daily maintenance
Lubricating oil inspection: Lubricating oil is as important to Roots blowers as blood is to the human body. It is responsible for lubricating the key components such as gears and bearings inside the blower, and can effectively reduce the friction and wear of these components during operation, thereby reducing energy loss and improving the operating efficiency of the blower. Regularly checking the oil level and quality of the lubricating oil is a key link in daily maintenance work. Generally speaking, the main and auxiliary oil tanks of Roots blowers are equipped with oil level mirrors on the outside. By observing the oil level mirror, we can clearly understand the oil level of the lubricating oil. The right amount of lubricating oil should be located above the red dot on the oil level mirror or between the two red straight lines. The ideal state is to keep it slightly higher than the middle of the two lines by 3-5mm. If the oil level is found to drop, the lubricating oil should be added in time to ensure that there is enough lubricating oil in the tank. In addition to checking the oil level, the inspection of oil quality should not be ignored. We can take some oil samples from the bottom of the tank, rub them between our fingers, and carefully observe their adhesion and impurities. If the oil sample is not very sticky, it means that the oxidation degree of the lubricating oil is not serious, and it may be necessary to filter out the impurities in it and continue to use it; but if the oil sample is very sticky and contains a lot of colloid, it means that the lubricating oil has seriously deteriorated and must be replaced in time. Observing the color of the lubricating oil is also an effective way to judge the oil quality. If the color is black and the color does not become significantly lighter after filtering, it means that there are too many impurities in the lubricating oil and it can no longer meet the lubrication needs and needs to be replaced. When detecting the moisture in the lubricating oil, we can use dry cotton yarn to dip a small amount of lubricating oil in the oil tank and then ignite the cotton yarn. If you hear an explosion or see a flash, it means that there is water in the oil, and the moisture in the oil is easy to form bubbles, causing the oil to lose its lubricating function. At this time, the lubricating oil must be replaced immediately. It is usually recommended to check the lubricating oil once every three months and replenish or replace it according to the actual situation. The first oil change should be carried out after the new fan has been running for about 500 hours.
Filter cleaning: During the operation of the Roots blower, a large amount of air needs to be inhaled, and the air often contains pollutants such as dust and impurities. The air inlet filter is like a "guardian" of the fan, which can effectively filter these impurities and prevent them from entering the fan, thereby reducing the wear of internal components and the occurrence of failures. Regular cleaning of the filter is an important measure to ensure its normal operation. The frequency of cleaning varies according to the use environment and working conditions. In general, it is recommended to clean the filter once a month; if the use environment is dusty, the cleaning frequency needs to be increased appropriately. When cleaning, for filters with dirty surfaces, clean compressed air can be used to blow on both sides until no dust particles can be seen under light. It should be noted that if a water-washable filter is used, the filter cotton needs to be replaced, because the filter cotton after water washing often can no longer achieve the ideal filtering effect. When the filter mesh is found to be damaged after cleaning, or the filter is deformed or damaged, a new filter should be replaced in time. The main component of the filter element at the air inlet is the filter cotton. During daily maintenance, if the air intake effect is found to be unsatisfactory, the filter element should also be replaced in time. During the process of cleaning impurities, special attention should be paid to the protection of the filter to avoid deformation, damage, etc., otherwise the reinstalled filter will not be able to play its due filtering role.
Operation status monitoring: Closely monitoring the operation status of the Roots blower every day is an important means to promptly detect potential problems and ensure the stable operation of the blower. Temperature monitoring is one of the important contents of operation status monitoring. We need to check the inlet and outlet temperatures of the blower every day to ensure that it is within the normal range. High temperature is often a signal of poor lubrication or increased mechanical friction. Once the temperature is abnormally high, it must be stopped immediately for inspection to find out the cause and solve it in time to avoid damage to the equipment due to overheating. Vibration detection should not be ignored either. Regularly detecting the vibration of the blower can help us detect problems such as bearing damage or impeller imbalance in time. Abnormal vibration may cause loosening of blower components, increased wear, and even cause serious equipment failure. By using professional vibration detection instruments, we can accurately measure the vibration amplitude and frequency of the blower, compare it with the normal operating data, and determine whether the blower is abnormal. Noise observation is also a key link in operating status monitoring. Pay attention to noise changes during fan operation. Abnormal noise may indicate loose, worn or other faults of internal parts. The noise of a normally operating Roots blower is relatively stable and within a reasonable range. If sharp, harsh or other abnormal noises occur, it must be checked immediately to determine the source of the noise and take appropriate measures to repair it. Pressure and flow monitoring are essential to ensure that the fan operates under optimal conditions. We need to record the pressure and flow data of the fan and compare them with the standard values. If the pressure or flow fluctuates abnormally, it may be caused by damage to the internal components of the fan, pipe blockage or other reasons. It is necessary to troubleshoot the problem in time and adjust the operating parameters of the fan to ensure the normal operation of the fan.
(II) Regular maintenance items
Impeller clearance inspection and adjustment: As the core component of the Roots blower, the size of the gap between the impeller and the casing and wall panel has a crucial impact on the performance and service life of the blower. When the gap between the impeller and the casing is too small, the impeller is prone to friction with the casing during high-speed rotation, which will not only cause physical damage to the impeller and the casing, but may also cause equipment failure and affect the normal operation of the blower; when the gap is too large, the efficiency of the Roots blower will be significantly reduced, the degree of compression will be reduced, and the air cannot be effectively pushed out, thus failing to meet the production process requirements for air volume and air pressure. In order to ensure the efficient and stable operation of the Roots blower and extend its service life, regular inspection and adjustment of the impeller clearance is an essential maintenance item. Generally speaking, an appropriate gap between the impeller and the casing can reduce friction, reduce energy loss, and improve the operating efficiency of the blower. The method of adjusting the impeller clearance is relatively complicated and requires professional techniques and tools. Before adjustment, first stop the operation of the Roots blower and cut off the power supply to ensure safe operation. Then open the cover of the Roots blower, and be careful not to damage the impeller during the process of opening the cover. Use tools to adjust the position of the impeller, which can usually be achieved by increasing or decreasing the number of gaskets. Increasing the number of gaskets can increase the gap between the impeller and the casing, and vice versa. After the adjustment is completed, the Roots blower needs to be started again for testing to ensure that its performance is normal, including indicators such as air volume, air pressure, vibration and noise are within the normal range. When adjusting the impeller gap, it is necessary to strictly follow the technical requirements and operating procedures of the equipment to ensure the accuracy and reliability of the adjustment.
Equipment calibration and precision adjustment: Regular calibration and precision adjustment of the Roots blower is an important measure to ensure its normal operation and maintain good performance. Calibration involves many aspects, including key components and systems such as mechanical seals, frequency converters, pressure sensors, and flow sensors. Mechanical seals are important devices to prevent gas leakage inside the blower. Regular inspection and calibration of mechanical seals can ensure their good sealing performance and avoid energy loss and environmental pollution caused by gas leakage. If signs of wear or aging are found in the mechanical seal, the seal should be replaced in time to ensure the normal operation of the blower. The frequency converter is a key device for adjusting the speed of the Roots blower. By calibrating the frequency converter, the speed of the blower can be accurately controlled, so that the air volume and air pressure of the blower can be flexibly adjusted according to the actual working conditions to achieve the purpose of energy saving and consumption reduction. When calibrating the frequency converter, it is necessary to use professional calibration instruments and adjust them according to the technical parameters and operation manual of the equipment to ensure that the output frequency and voltage of the frequency converter are stable and match the operating requirements of the blower. Pressure sensors and flow sensors are important tools for monitoring the operating status of Roots blowers. Regular calibration of these sensors can ensure the accuracy of their measurement data and provide reliable operating information for operators. If the sensor measurement is inaccurate, it may cause the operator to misjudge the operating status of the blower, thereby affecting the normal progress of the production process. When calibrating the sensor, it is necessary to use a standard pressure source and flow source to calibrate and adjust the sensor to ensure that its measurement accuracy meets the requirements. In addition to calibrating these key components and systems, it is also necessary to test and adjust the overall performance of the blower, including indicators such as air volume, air pressure, power, and efficiency. By comparing with the design parameters of the equipment, find out the reasons for performance deviation and take corresponding measures to make adjustments, such as adjusting the impeller gap, cleaning the filter, checking the sealing of the pipeline, etc., to ensure that the Roots blower is always in the best operating state.
Inspection and replacement of key components: During the long-term operation of the Roots blower, some key components will inevitably have problems such as wear and aging. If these problems are not handled in time, they will affect the normal operation of the blower and even cause serious equipment failures. Therefore, regular inspection and replacement of these key components are important maintenance measures to ensure the stable operation of the Roots blower. Bearings are important components that support the rotation of the impeller in the Roots blower. During the operation of the blower, the bearings bear huge loads and friction, and are prone to wear, pitting, peeling and other problems. Check the wear of the bearings regularly. If obvious wear, pitting or peeling is found on the inner and outer rings and rolling elements of the bearings, the bearings should be replaced in time. When replacing bearings, high-precision bearings that match the original models should be selected, such as products from well-known brands such as SKF and NSK, to ensure the quality and performance of the bearings. Pay attention to the control of bearing clearance during installation. Generally, the clearance should be controlled within the range of 0.05-0.10mm. Use special tools to press the bearings and avoid direct knocking to avoid damaging the bearings. Gears are key components of the Roots blower transmission system. Their function is to transmit power and ensure the synchronous rotation of the impeller. During the operation of the blower, the gears will be subjected to large torque and impact force, and are prone to wear, tooth surface fatigue, broken teeth and other problems. Check the wear of the gears regularly. If the gear side clearance exceeds 0.18mm, the tooth surface is severely worn or broken teeth appear, the gears should be replaced in time. When replacing the gears, ensure that the modulus, number of teeth, tooth shape and other parameters of the new gears are consistent with the original gears. After installation, check the meshing of the gears to ensure that the gear meshing contact area is ≥75%, the leaf gap is ≥0.15mm, and the hinge gap is ≥0.30mm. Seals are important components to prevent gas leakage inside the blower, including oil seals, gas seals, etc. During the operation of the fan, the seals will be affected by factors such as high temperature, high pressure, and wear, and are prone to aging, deformation, and damage. Check the wear of the seals regularly. If the seals show signs of aging, deformation, and damage, they should be replaced in time. When replacing seals, choose products of reliable quality and apply an appropriate amount of grease during installation to avoid dry friction of the seals during installation and operation, which affects the sealing performance.
(III) Troubleshooting and Solutions
Common faults and their impact on functions: Various faults may occur during the operation of the Roots blower, which will have different degrees of impact on its function. Insufficient air volume is one of the more common faults, and the reasons for its occurrence may be multifaceted. The blockage of the inlet filter is one of the common reasons for insufficient air volume. When the filter is blocked by dust, impurities, etc., the resistance of air entering the blower increases, resulting in a decrease in air volume. Impeller wear causes excessive gaps in various parts, which will also increase the amount of gas leakage inside the blower, resulting in insufficient air volume. Too long pipes and air leakage will also affect the air volume. Too long pipes will increase the flow resistance of the gas, and air leakage will cause part of the gas to leak out during the transportation process and fail to reach the destination. Belt slippage is also one of the reasons for insufficient air volume. When the belt is loose, worn or aged, the friction between the belt and the pulley decreases, and it is easy to slip, causing the speed of the blower to decrease, thereby affecting the air volume. Insufficient air volume will make the Roots blower unable to meet the gas flow requirements of the production process. In sewage treatment plants, insufficient air volume will lead to insufficient oxygen supply in the aeration tank, affecting the normal metabolism of microorganisms and reducing the sewage treatment effect; in pneumatic conveying systems, insufficient air volume will lead to poor material conveying and affect production efficiency.
Motor overload is also one of the common faults of Roots blowers. The reason may be that the filter is blocked, resulting in increased air intake resistance of the blower. The motor needs to overcome greater resistance to drive the blower to operate, resulting in motor overload. The actual operating pressure of the blower exceeds the rated working pressure marked on the factory nameplate, which will also increase the load of the motor and cause the motor to overload. Abnormal friction between the impeller and the cylinder will increase the load of the motor and also cause the motor to overload. Motor overload will increase the current of the motor and increase the temperature. If it is in an overloaded state for a long time, it may cause the motor to burn out and make the Roots blower unable to work normally.
Fan overheating is also a common fault. The cause may be overload operation. When the fan runs for a long time at a load exceeding its rated load, the motor and internal components of the fan will generate too much heat, causing the fan to overheat. If the fan inlet filter is blocked, the air intake will be reduced, and the heat inside the fan cannot be dissipated in time, causing the fan to overheat. The larger the gap between the various parts of the shell, the more gas will leak inside the fan, thereby increasing the power consumption of the fan and causing the fan to overheat. The lack of lubricating oil or poor quality will not provide good lubrication for the internal components of the fan, which will increase the friction between the components and generate too much heat, causing the fan to overheat. Fan overheating will affect the normal operation of the fan, reduce the service life of the fan, and may even cause equipment failure.
Troubleshooting methods and techniques: When a Roots blower fails, accurately and quickly troubleshooting the cause of the failure is the key to solving the problem. Troubleshooting requires the comprehensive use of multiple methods and techniques to analyze and judge from multiple aspects. Observing the operating status of the fan is the first step in troubleshooting. Carefully observe whether there are abnormal sounds, vibrations, smoke, etc. during the operation of the fan. Abnormal sounds may be caused by loose, worn, and collided internal parts of the fan. For example, the friction between the impeller and the casing will produce sharp friction sounds, and bearing damage will produce abnormal noise. Excessive vibration may be caused by unbalanced impellers, worn bearings, and unstable foundations. By observing the amplitude and frequency of vibration, the cause of the fault can be preliminarily determined. Smoke may be caused by motor overheating, electrical short circuit, etc. Once smoking is found, it must be stopped immediately for inspection to avoid serious accidents such as fire.
Checking the various parameters of the fan is also an important method for troubleshooting, including temperature, pressure, flow, current, etc. By comparing the actual parameters with the rated parameters and normal operating parameters of the equipment, it is determined whether there is an abnormality. If the temperature is too high, it may be caused by fan overload, poor lubrication, poor heat dissipation, etc.; if the pressure is abnormal, it may be caused by pipeline blockage, valve failure, damage to internal parts of the fan, etc.; if the flow is insufficient, it may be caused by reasons such as inlet filter blockage, impeller wear, pipeline leakage, etc.; if the current is too large, it may be caused by motor overload, electrical failure, etc.
Inspecting the various components of the fan is also a key link in troubleshooting. Check whether the inlet filter is blocked, whether the impeller is worn or deformed, whether the bearing is damaged, whether the seal is aging or damaged, whether the pipeline is leaking, etc. When checking the inlet filter, the filter can be disassembled to observe whether there is a large amount of dust and impurities accumulated on its surface. If the filter is seriously blocked, it needs to be cleaned or replaced. When checking the impeller, carefully observe whether the impeller blades are worn, deformed, broken, etc., and whether the gap between the impeller and the casing and wallboard is normal. When checking the bearing, check whether the inner and outer rings and rolling elements of the bearing are worn, pitted, peeled off, etc., and whether the bearing clearance is normal. When checking the seal, check whether the seal is aging, deformed, damaged, etc., and whether the seal between the seal and the sealing surface is good. When checking the pipeline, check whether the pipeline has cracks, damage, loose connections, etc., and whether the support of the pipeline is firm.
Fault solution measures and case analysis: According to different fault causes, corresponding solutions need to be taken. When the air volume is insufficient, if it is caused by the blockage of the inlet filter, the filter should be cleaned in time to remove the dust, impurities and other blockages, and the filter should be replaced if necessary; if the gap between each part is too large due to impeller wear, the gap needs to be repaired to ensure that the gap between the impellers is within the specified range, such as by adjusting the thickness of the gasket or replacing the worn impeller to restore the gap; if the pipeline is too long and leaking, the joints should be tightened and the leaking parts should be repaired. For pipelines that are too long, consider optimizing the pipeline layout to reduce the gas flow resistance; if it is caused by belt slippage, the belt should be tightened to increase the friction of the belt, and a new belt should be replaced if necessary.
In a sewage treatment plant, a Roots blower had a problem with insufficient air volume. After investigation, it was found that the imported filter was seriously clogged. The maintenance personnel cleaned the filter in time and replaced the filter cotton. The air volume of the blower returned to normal, the oxygen supply in the aeration tank was sufficient, and the sewage treatment effect was significantly improved.
When the motor overload failure occurs, if it is caused by the filter blockage, the filter should be cleaned, the blockage should be removed, and the air intake resistance of the blower should be reduced; if the actual operating pressure of the blower exceeds the rated working pressure, it is necessary to check the exhaust system, adjust the valve opening, and reduce the actual operating pressure of the blower; if the friction between the impeller and the cylinder is abnormal, it is necessary to adjust the gap between the impeller and the cylinder, repair the worn parts, and ensure the normal cooperation between the impeller and the cylinder.
In the pneumatic conveying system of a cement plant, a Roots blower had a motor overload failure. After inspection, it was found that the actual operating pressure of the blower exceeded the rated working pressure and there was slight friction between the impeller and the cylinder. The maintenance personnel adjusted the opening of the exhaust valve to reduce the actual operating pressure of the fan. At the same time, they adjusted the gap between the impeller and the cylinder, repaired the worn parts, solved the motor overload problem, and restored the pneumatic conveying system to normal operation.
When the fan overheats, if it is caused by overload operation, the fan load should be adjusted to avoid overload operation, and the production tasks should be arranged reasonably to ensure that the fan operates within the rated load range; if the fan inlet filter is blocked, the blockage of the inlet filter should be cleared to ensure smooth air intake so that the heat inside the fan can be dissipated in time; if the gaps in various parts of the shell become larger, it is necessary to check and repair the gaps in various parts of the shell to reduce gas leakage and reduce the power consumption of the fan; if the lubricant is missing or the quality is too poor, the new lubricant should be replaced to ensure the good quality of the oil, provide good lubrication for the internal parts of the fan, and reduce friction and heat generation.
In a chemical enterprise, a Roots blower overheated. After inspection, it was found that the lubricant was missing and the quality was too poor. The maintenance personnel promptly replaced the lubricating oil that met the requirements, and the temperature of the blower gradually returned to normal. The equipment operated stably, ensuring the smooth progress of chemical production. Through these cases, we can see that accurately troubleshooting the cause of the fault and taking effective solutions can solve the fault of the Roots blower in a timely manner, ensure its normal operation, and provide reliable protection for industrial production.
VIII. Future Outlook: Possibility of Functional Expansion
(I) Impact of Technology Development Trends on Functions
Intelligent Control Technology: With the rapid development of science and technology, the application prospects of intelligent control technology in the field of Roots blowers are extremely broad, and it is expected to bring revolutionary improvements to the functions of blowers. Intelligent control technology mainly includes advanced algorithms such as adaptive control, predictive control, and fuzzy control. By introducing adaptive control algorithms into Roots blowers, the blowers can sense their own operating status and changes in external working conditions in real time, such as fluctuations in parameters such as gas flow, pressure, and temperature, and then automatically and accurately adjust their own operating parameters, such as speed and blade angle, to ensure that they always operate under the best working conditions. This can not only significantly improve the operating efficiency of the blower and reduce energy consumption, but also enhance the adaptability of the blower to complex working conditions, so that it can work stably and efficiently in different working environments.
In some industrial production processes that have strict requirements on gas flow and pressure, such as chemical production and pharmaceutical industries, adaptive control technology can enable Roots blowers to quickly and accurately adjust output according to the real-time needs of the production process to ensure the continuity and stability of the production process. The predictive control algorithm can use advanced data analysis and prediction models to predict possible faults and changing trends of the fan's operating status in advance based on the fan's historical operating data and real-time monitored parameters. In this way, the operation and maintenance personnel can take corresponding measures in advance, such as preventive maintenance and adjustment of operation strategies, to effectively avoid the occurrence of faults, reduce downtime, and improve the reliability and availability of the fan.
Fuzzy control technology provides an effective solution for Roots blowers when dealing with some complex systems that are difficult to accurately model. In actual operation, the performance of the fan is affected by a variety of factors, and there are often complex nonlinear relationships between these factors, which are difficult to accurately describe using traditional mathematical models. Fuzzy control technology can simulate human thinking, convert the operator's experience and knowledge into fuzzy rules, and realize intelligent control of the fan through fuzzy reasoning and decision-making. When faced with working conditions where factors such as gas composition, temperature, and humidity change frequently, fuzzy control technology can enable Roots blowers to respond quickly and accurately, maintain a stable operating state, and improve the control accuracy and stability of the fan.
Application of new materials: The continuous emergence and application of new materials have opened up new ways for the improvement of Roots blower performance and the expansion of functions. In terms of impeller materials, although traditional cast iron and cast steel materials have certain strength and wear resistance, they have certain limitations in weight and corrosion resistance. New composite materials, such as carbon fiber reinforced composite materials (CFRP) and glass fiber reinforced composite materials (GFRP), have many advantages such as light weight, high strength, corrosion resistance and wear resistance. The use of these new composite materials to manufacture impellers can significantly reduce the weight of the impeller and reduce the rotational inertia of the fan, thereby increasing the starting and braking speed of the fan and reducing energy consumption. These composite materials also have excellent corrosion resistance, can effectively resist the erosion of various corrosive gases and media, extend the service life of the impeller, and enable the Roots blower to operate stably under more severe working conditions.
In terms of casing materials, traditional metal casings have problems such as heavy weight, high cost and easy corrosion. In recent years, with the continuous advancement of plastic material technology, high-performance engineering plastics have gradually become a new choice for casing materials. These engineering plastics have the advantages of light weight, low cost, corrosion resistance, and good insulation. They can effectively reduce the weight and cost of the fan and improve the corrosion resistance and safety of the fan. Some casings made of high-performance engineering plastics such as polyetheretherketone (PEEK) not only have excellent mechanical properties and chemical stability, but also effectively reduce the noise during the operation of the fan, providing users with a quieter and more comfortable working environment.
In terms of sealing materials, new fluororubber materials and polytetrafluoroethylene (PTFE) materials have excellent temperature resistance, corrosion resistance and wear resistance, which can effectively improve the sealing performance of the fan, reduce gas leakage, and improve the efficiency and reliability of the fan. In some occasions with strict requirements on gas leakage, such as conveying flammable and explosive gases or high-purity gases, the use of these new sealing materials can ensure the safe operation of the fan and avoid safety accidents and quality problems caused by gas leakage.
(II) Prediction of potential new application areas
New energy field: In the field of new energy, Roots blowers have broad application prospects, especially in wind power generation and hydrogen energy industries. In wind farms, Roots blowers can be used in the cooling system of wind turbines. With the continuous increase in the capacity of wind turbines, a large amount of heat will be generated during the operation of the unit. If it cannot be dissipated in a timely and effective manner, it will affect the performance and service life of the unit. Roots blowers cool the unit by introducing external cold air into the unit, exchanging heat with the heat-generating components, and then discharging the hot air. Because Roots blowers have the characteristics of stable delivery and constant flow, they can provide stable cooling air volume for wind turbines, ensure that the unit can maintain a good operating temperature under various working conditions, and improve the power generation efficiency and reliability of the unit.
In the hydrogen energy industry, Roots blowers can be used in the transportation and compression of hydrogen. As a clean and efficient new energy source, the production, storage and transportation of hydrogen are key links to achieve large-scale application. Roots blowers can compress and transport the produced hydrogen to meet the requirements of different users for hydrogen pressure and flow. In hydrogen refueling stations, Roots blowers can compress hydrogen to a certain pressure and store it to provide hydrogen refueling services for fuel cell vehicles, etc. Due to the flammable and explosive characteristics of hydrogen, the safety and sealing of the transportation equipment are extremely high. By adopting a special sealing structure and explosion-proof design, Roots blowers can ensure the safety and reliability of hydrogen during transportation, providing strong support for the development of the hydrogen energy industry.
Environmental protection field: In the field of environmental protection, Roots blowers will also play an increasingly important role, especially in the treatment of volatile organic compounds (VOCs) and landfill gas treatment. In VOCs treatment, Roots blowers can be used for the collection and transportation of waste gas. Many industrial production processes, such as chemical, coating, printing, etc., will produce a large amount of waste gas containing VOCs. If these waste gases are directly discharged into the atmosphere, they will cause serious harm to the environment and human health. Roots blowers collect waste gas containing VOCs by generating negative pressure, and then transport it to subsequent treatment equipment, such as adsorption devices, combustion devices, etc., for purification. Because Roots blowers have the characteristics of wide applicability and strong compatibility, they can adapt to the transportation needs of VOCs waste gas of different components and concentrations, providing reliable equipment guarantee for VOCs treatment.
In landfill gas treatment, Roots blowers can be used to collect, compress and transport the biogas generated in the landfill. Under the decomposition of microorganisms, organic matter in the landfill will produce a large amount of biogas, the main components of which are methane and carbon dioxide. If biogas is not effectively collected and treated, it will not only cause energy waste, but also pollute the environment. After collecting biogas, Roots blowers can compress and transport it, and use it in power generation, heating and other fields to achieve energy recycling. Roots blowers can also provide gas transportation and stirring functions for purification equipment during biogas purification, improve the purification efficiency of biogas, and ensure that the quality of biogas meets the use requirements.
IX. Conclusion: Summary of the value of Roots blower functions
As an indispensable and important equipment in the industrial field, Roots blower plays a key role in many fields such as sewage treatment, pneumatic conveying, cement, aquaculture, food, chemical and petrochemical industries, and electricity with its unique gas conveying and pressurization functions, providing stable and reliable support for the production activities of various industries, and has a profound impact on economic development and social progress.
In the field of sewage treatment, Roots blower provides oxygen for microorganisms and stirs sewage, which greatly improves the sewage treatment effect and effectively protects water resources and the ecological environment; in the field of pneumatic conveying, it realizes the efficient conveying of powdered and granular materials with stable airflow and efficient conveying capacity, and is widely used in grain, cement, chemical raw materials and other industries, which effectively promotes the efficient production of these industries; in the cement industry, Roots blower provides power for cement production equipment, is a key equipment to ensure the smooth progress of cement production, and plays a decisive role in improving cement production efficiency; in the field of aquaculture, Roots blower Increasing the dissolved oxygen content in water and improving the breeding environment have created good conditions for the growth and reproduction of aquatic organisms, significantly increasing the breeding output; in the food industry, Roots blowers play an important role in food raw material transportation and packaging gas protection, providing a solid guarantee for the safe production and preservation of food; in the chemical and petrochemical fields, Roots blowers are indispensable in key links such as raw gas preparation and gas transportation, and are an important guarantee for the smooth progress of chemical production; in the power field, Roots blowers play an important role in coal powder combustion, pneumatic ash conveying and other links, providing strong support for the stable operation of power production.
Roots blowers have many advantages such as simple structure, convenient maintenance, stable transportation, constant flow, wide application, strong compatibility, high efficiency and energy saving, economical and practical, stable operation, low noise, long life and high reliability. These advantages make it have extremely high application value and competitiveness in the industrial field. However, Roots blowers also have limitations such as limited pressure, insufficient high pressure, high energy consumption, efficiency to be improved, noise troubles, environmental impact, volume and weight, installation challenges, medium sensitivity, necessary protection, starting characteristics, and current shock. In practical applications, we need to fully realize these advantages and limitations, and reasonably select and use Roots blowers according to specific working conditions to give full play to their advantages, while taking corresponding measures to overcome their limitations.
In order to ensure the stable function of Roots blowers, daily maintenance and regular maintenance are essential. Through daily maintenance measures such as regular inspection of lubricating oil, cleaning of filters, monitoring of operating status, and regular maintenance items such as inspection and adjustment of impeller clearance, calibration of equipment accuracy, and replacement of key components, potential problems can be discovered and solved in a timely manner to ensure the normal operation of the blower and extend its service life. When a Roots blower fails, we need to accurately identify the cause of the failure and take effective solutions to restore the normal function of the blower and ensure the smooth progress of production activities.
Looking to the future, with the continuous development of technologies such as intelligent control technology and new material applications, Roots blowers are expected to achieve further breakthroughs and improvements in performance and function. Intelligent control technology will enable Roots blowers to more intelligently sense and adapt to changes in working conditions, achieve more precise control and efficient operation; the application of new materials will provide new ways to improve the performance of Roots blowers, such as lightweight, corrosion resistance, and high strength, so that they can operate stably under more severe working conditions. Roots blowers have broad application prospects in the fields of new energy and environmental protection, and are expected to provide new equipment support and technical guarantees for the development of these fields. In wind farms, Roots blowers can be used in the cooling system of wind turbines; in the hydrogen energy industry, Roots blowers can be used in the transportation and compression of hydrogen; in the field of environmental protection, Roots blowers can be used in the treatment of volatile organic compounds (VOCs) and landfill gas treatment.
As an important equipment in the industrial field, Roots blowers play an irreplaceable role in various industries. In future development, we should continue to pay attention to the technological innovation and application expansion of Roots blowers, give full play to their advantages, overcome their limitations, and make greater contributions to industrial production and social development. I believe that driven by both technological progress and market demand, Roots blowers will usher in a brighter development prospect and demonstrate their unique value and charm in more fields.
