BlowerIt mainly consists of the following six parts:electric machinery、Air filterBlower bodyAir chamberBase (also used as oil tank) and oil drip nozzle.Blower leancylinderInternally biasedrotorEccentric operation, and the volume change between the blades in the rotor slot will suck, compress and spit out air.Using the blower'sPressure differenceAutomatically send lubrication to the oil drip nozzle and drip into the cylinder to reduce friction andNoiseAt the same time, it can keep the gas in the cylinder from returning. This kind of blower is also called sliding vane blower.[1]
Chinese name
Blower[1]
Foreign name
Blower[1]
Alias
Sliding vane blower[1]
Application
Ventilation, coal, power, oil and other industrial fields[1]
Impeller machinery is a device that transmits energy to the continuous flow fluid by the dynamic action of the blades on the rotating impeller or pushes the blades to rotate by the energy transmitted from the fluid.In turbomachinery, rotating blades do positive or negative work on the fluid to increase or decrease the pressure of the fluid.Impeller machinery is divided into two categories: one is working machine, from which fluid absorbs power to increase head or water head, such as vane pump and fan;The other is prime mover, in which fluid expands, reduces pressure or water head to generate power, such as steam turbine and water turbine.The prime mover is called a turbine, and the working machine is called a blade type fluid machine.[1]
According to the different working principles of fans, they can be divided into two categories: blade type and volumetric type. The blade type can also be divided into axial flow type, centrifugal type and mixed flow type.According to the pressure generated by the fan, it can be divided into blower, compressor and ventilator.According to the current mechanical industry standard JB/T2977-92, the fan refers to the fan whose outlet pressure (gauge pressure) is less than 0.015MPa when the inlet is standard air;The blower is called when the outlet pressure (gauge pressure) is between 0.015MPa and 0.2MPa;The outlet pressure (gauge pressure) greater than 0.2MPa is calledcompressor。[1]
The collector can guide the gas to the impeller, and the flow condition at the inlet of the impeller is guaranteed by the geometry of the collector.There are many kinds of collector shapes, mainly: cylindrical, conical, conical, arc, cylindrical arc, arc conical, etc.[1]
The impeller is generally composed of four parts: wheel cover, wheel disk, blade and shaft disk. The connection mode of its structure is mainlyweldingandriveting。according toimpellerThe outlet of the valve can be divided into three types: radial, forward and backward.Impeller isCentrifugal fanThe most important part, driven by the prime mover, isCentrifugal impellerThe heart of the machine is responsible for the energy transmission process described by the Euler equation. The flow inside the centrifugal impeller is affected by the rotation and surface curvature of the impeller, and is accompanied by the phenomena of flow separation, backflow and secondary flow, which makes the flow inside the impeller very complex.The flow condition inside the impeller directly affects the aerodynamic performance and efficiency of the whole stage and the whole machine.[1]
The volute is mainly used to collect the gas from the impeller. At the same time, it can convert the kinetic energy of the gas into the static pressure energy of the gas by moderately reducing the gas speed, and guide the gas to leave the volute outlet.As a fluid impeller machine, it is a very effective method to improve the performance and efficiency of the blower by studying its internal flow field.In order to understandCentrifugal blowerThe actual flow conditions inside the impeller and volute were improved to improve the performance and efficiency. A lot of basic theoretical analysis, experimental research and numerical simulation were done for the centrifugal impeller and volute.[1]
Bearing: 3000 double row centripetal spherical roller bearing is selected as the locating end near the coupling end.As the free end, the near gear end selects 32000 single row radial short cylindrical roller bearing to adapt to the axial displacement of the rotor during thermal expansion.[1]
Synchronous gear: composed of gear ring and hub, which is convenient for adjusting the impeller clearance.[1]
Engine body: it is composed of the casing and left and right wallboards.The left and right wallboards and the bearing seats and sealing parts installed in the left and right wallboards can be mutually used.[1]
Base: small and medium-sized fans are equipped with a common base, while large fans are only equipped with a fan base, which is convenient for installation and commissioning.[1]
Lubrication: gears are immersed and bearings are splash lubricated.Good lubrication effect, safe and reliable.[1]
Transmission mode: direct coupling is the main mode.If required by performance specifications, V-belt pulley speed change mode can also be selected.Elastic coupling is selected as the coupling, which can mitigate impact and compensate a small amount of axis deviation.The large flow fan can also use steam turbine or other drivers, except that the motor is used as the driver.[1]
Product History
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Metallurgy appeared in China 5000~6000 years ago.After entering the Iron Age in the 5th century BC, iron became an important factor in promoting historical progress and once became a symbol of the level of productivity development.Iron smelting is a combination of various technologies, and blast technology is an indispensable part of it.In ancient China, the blast technology of metallurgical machinery experienced the development from intermittent blast to continuous blast, and the blast equipment developed from leather Ligularia to wooden fan and piston type wooden bellows, during which horse row and water row also appeared.The development of blast equipment is not only an important part of iron smelting technology progress, but also affected by the overall level of mechanical technology as a kind of mechanical technology.China's iron smelting machinery shows a unique development thread under the combined force of social, political, economic, technical and other factors.[2]
The blast technology is to blow the air flow under certain pressure into the furnace to fully burn the fuel, improve the furnace temperature and smelting efficiency.The blast equipment is the material basis for the implementation of blast technology.Natural wind may be used in early metallurgy, and then forced blast is developed with the demand for high temperature.The earliest instruments used for forced air blowing were fans and blowpipes (Ligularia).The remains of a copper smelting crucible furnace found in Niuheliang, Lingyuan County, Liaoning Province, are typical archaeological evidence of pipe blowing. A pottery animal head blast pipe was also found in the Dajing ancient copper mine site (Xiajiadian upper culture, about 2700~2900 years ago) in Linxi County, Chifeng City, Inner Mongolia.These findings indicate that primitive blast equipment had appeared in the early Bronze Age.According to the existing archaeological excavation materials, as early as the Western Zhou Dynasty, China had used smelting equipment with one furnace and four blowers.In addition, it can be inferred from a large number of bronze wares unearthed in the Shang and Zhou Dynasties and their technological level that there should have been a relatively primitive air blowing device at that time, but whether this air blowing device belongs to a mechanical device remains to be further verified.The real iron smelting blast mechanism should be developed with the progress of iron smelting. The concept of machinery appeared in the Spring and Autumn Period and the Warring States Period.Zhuangzi · Waipian · Heaven and Earth records Zigong's words: "There are weapons (" weapons "are a kind of water collecting tools).In this way, I can soak hundreds of beds in one day, and I can do a lot of good with little effort. "《Han Feizi, Naner》He said: "If we consider the terrain, we can benefit from the boat and machinery. If we use less force and do more work, we will get more".That is to say, the ancients believed that machinery was a kind of instrument that "uses less force to achieve more results".Now it is generally believed that machinery should include three parts: power device, transmission device and working machine.If the blower machinery is measured in this way, the earliest one is Ligularia virgaurea, followed by water drainage, wooden fan, piston type wooden bellows, etc.It is not difficult to see that the mechanical structure and mechanical driving force of Ligularia virgaurea from the initial stage to the subsequent horse row, water row, and then to the wooden fan and wooden bellows show a development vein from simple to complex, then to miniaturization and simplification.The reason for such characteristics was determined by the social background at that time, especially the national system and economic development.[2]
Product classification
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Roots blower
Roots blowerIt is a positive displacement blowerRotary blowerIt is a kind of pneumatic conveying system that uses two blade rotors or three blade rotors to make relative movement in the cylinder.Due to the continuous rotation of the rotor, the extracted gas is sucked into the air between the rotor and the pump casing from the air inlet, and then discharged through the exhaust portRoots Blower There is no internal compression process.[3]
Roots blower is commonly used in small and medium-sized sulfuric acid plants.When the required air volume is small, the centrifugal blower is often not applicable because the impeller diameter is small and it is difficult to reach the pressure head required for sulfuric acid production under the speed of 2950 revolutions per minute.Roots blower has the advantages of both reciprocating compressor and centrifugal blower. It has the advantages that the air pressure of the reciprocating compressor changes slightly when the rotating speed is fixed, and the air supply volume can remain unchanged, that is, it maintains the proportional relationship between the rotating speed and the air volume. It also has the advantages of high rotating speed of centrifugal blower, no air valve and crankshaft, light weight, convenient application, etc.The disadvantage is that when the outlet is blocked, it is easy to increase the pressure and even cause damage to the machine itself.After a long time of use, the air supply volume decreases due to the expansion of the gap between the two rotors and the gap between the rotor and the casing.[4]
Blast furnace blower
currentBlast furnace blowerBlade fans are adopted, mainly including centrifugal and axial flow fans.The centrifugal blower has the advantages of simple structure, reliable operation, high efficiency at the design point and low noise.The centrifugal blast furnace blower has relatively mature manufacturing and use experience in China, 400mthreeThe following blast furnaces are widely used in underdeveloped regions and countries.However, with the increase of the blast furnace, the adjustment loss, overall dimensions and fan weight of the centrifugal blower have increased significantly, which has brought great difficulties to manufacturing, transportation, installation and maintenance. At the same time, it is also limited by rotating parts - impeller material strength, spindle stiffness, motor startup and other factors,It also reduces the reliability and economy of the fan operation.The axial flow blower has the characteristics of compact structure, small volume, light weight, good load regulation, wide application range, small fan moment of inertia, easy motor startup, etc., so it is widely used in large-scale and modern blast furnaces.500m in ChinathreeAxial flow blowers are widely used in the above blast furnaces, and certain experience has been accumulated in manufacturing and operation.[5]
Magnetic suspension blower
Magnetic suspension blowerIt is a kind of turbine with magnetic bearing.Its main structure is that the blower impeller is directly installed on the extension end of the motor shaft, while the rotor is vertically suspended on the active magnetic bearing controller, which does not need the speed increaser and coupling, and is directly driven by the high-speed motor.The core of single-stage high-speed centrifugal blower regulated by frequency converter ismagnetic bearing andPermanent magnet motorTechnology.Main technical features of magnetic suspension blower include:[6]
(1) High efficiency impeller:The high efficiency impeller is designed with three-dimensional flow, and the five axis machining technology ensures the manufacturing accuracy of the impeller.[6]
(2) Magnetic bearing:No mechanical wear, low energy, semi permanent life.[6]
(3) Integration of structural design:The fan impeller is directly installed on the motor shaft end, integrated with the control system, and assembled in the box, with simple and simple structure.[6]
(4) Convenient installation and maintenance:There is no need for lifting equipment and large space, no need for special foundation, convenient maintenance, and saving the infrastructure cost of the machine room.[6]
(5) System modular design: According to different user flow, multiple blowers are allowed to work in parallel, with wide adjustment range and strong flexibility.[6]
Advantages of magnetic suspension blower:[6]
(1) Energy efficient:The magnetic suspension bearing is adopted, without contact loss and mechanical loss, to realize the stepless speed change regulation of high speed.[6]
(2) High system integration:haveInlet filter, cooling system, fully automatic anti surge system, power failure and fault protection system, etc., bring the safety, convenience and reliability of operation.[6]
(3) High cooling efficiency:The cooling system adopts an external condenser, which can effectively protect the fan system and enable the fan to start and stop at any time.[6]
Single pole high-speed centrifugal blower
The monopole high-speed centrifugal blower has entered the 1990sCentrifugal compressorAnd blower design.The design of the monopole high-speed centrifugal blower adopts the three-dimensional flow design theory, which makes the efficiency of the monopole centrifugal blower reach more than 82%, far better than that of the multipole centrifugal blower. The structure adopts the axial inlet guide vane adjustment device. Under constant pressure, the flow is adjusted to 65%~105% of the rated current, and the flow adjustment range of a single set is 45%~100%,It makes the operation under low load conditions have higher efficiency, which is an advantage that low speed multipole blower and roots blower do not have.Because the monopole high-speed centrifugal blower has the characteristics of small size, light weight, high efficiency, energy saving, wide performance range adjustment and high automation level, it is now a sewage treatment industryAeration blowerMainstream products.[7]
Multistage centrifugal blower
Centrifugal blower is also calledTurbine blowerUnder the action of the rotating impeller, the pressure and flow rate of the gas increase, which can realize continuous air supply.Its working principle is that when the motor rotates to drive the fan impeller to rotate, the gas is thrown out and changes the flow direction under the action of centrifugal force, the kinetic energy is converted into static pressure energy, and the gas is discharged from the exhaust port. At the same time, a certain negative pressure is formed between the impellers, so that the external gas can be fed under the action of atmospheric pressure to achieve the purpose of continuous blowing.Centrifugal blowers are divided intoMultistage centrifugal blowerAnd single-stage centrifugal blower.The normal operation of multi-stage low-speed centrifugal blower refers to the centrifugal blower with two or more rotors connected in series on the same main shaft, at most eight stages of blades, and a rotor speed of 3000~3600r/min.Centrifugal blowers generally use inlet throttling to regulate the flow and pressure, so that the fan can operate at a lower power without exhaust regulation, and can maintain basically the same efficiency as the rated working condition, which is used for working conditions with unstable pressure and flow.[3]
The air supply volume of multistage centrifugal blower is generally large, but the air pressure generated is not high, the outlet gauge pressure is generally ≤ 110kPa, and the flow is generally 130mthree/Min.Compared with Roots blower, low-speed multistage centrifugal blower has gradually replaced Roots blower in foreign sewage treatment plants since the 1980s due to its advantages of low noise, stable and reliable fan operation, and high efficiency. However, it still has disadvantages such as large volume, heavy weight, poor flow regulation performance, low efficiency, and large energy consumption.[3]
Air suspension centrifugal blower
The air suspension centrifugal blower is a new concept centrifugal blowerturbogenerator, advanced air suspension technology and two high-end core technologies, "high-speed direct coupled motor" and "air suspension bearing", have been applied to improve the speed of traditional single-stage high-speed turbine blowerGear coupling, cooling system and oil lubrication system, greatly improving the technical performance and operational reliability of the product.[3]
Air suspension single-stage centrifugal blower adopts SVStitanium alloyThe material and impeller have strong deformation resistance, and the best efficiency angle is selected for design, with the efficiency up to 88%;BLDCM permanent magnet brushless ultraHigh speed motorWith the development of permanent magnet material technology, semiconductor technology and control technology, it is a new type of motor, which is more efficient and energy-saving;Frequency conversion adjustment mode is adopted to make the adjustable range of suspension centrifugal blower wider;The use of air self cooling technology can ensure that the blower can still maintain reliable working performance in hot summer. Due to the use of high-speed direct coupled motor, air suspension bearing and three-dimensional simulation turbine wheel, the energy consumption caused by mechanical transmission and mechanical friction is greatly reduced, so the efficiency is extremely high;Air bearing has longer service life than magnetic bearing, and the replacement price is relatively low;Start and stop do not depend on the power supply, and the operation is more stable and reliable than the magnetic suspension centrifugal blower;It can save 25%~35% energy compared with Roots blower, 15%~20% energy compared with traditional multi-stage centrifugal blower, and 10%~15% energy compared with traditional single-stage high-speed centrifugal blower.Air volume: 35~160 mthree/Min, the maximum outlet air pressure reaches 100kPa.[3]
working principle
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Working principle of centrifugal blower[8]
Centrifugal blowerWorking principle andCentrifugal fanSimilar, except that the air compression process usually passes through several working impellers (or stages)centrifugal forceUnder the action of.The blower has a high-speedrotorThe blades on the rotor drive the air to move at a high speed. The centrifugal force makes the air flow to the fan outlet along the involute in the involute casing. The high-speed air flow has a certain air pressure.The fresh air enters and replenishes from the center of the casing.[8]
The working principle of the single-stage high-speed centrifugal fan is that the prime mover drives the impeller to rotate at a high speed through the shaft. The air flow enters the high-speed rotating impeller from the inlet axial direction and becomes radial flow, which is accelerated, then enters the diffuser chamber, changes the flow direction and decelerates. This deceleration effect converts the kinetic energy in the high-speed rotating air flow into pressure energy（potential energy）Keep the fan outlet at a stable pressure.[8]
Theoretically, the pressure flow characteristic curve of centrifugal blower is a straight lineFrictional resistanceThe actual pressure and flow characteristic curve decreases gently with the increase of flow, and the corresponding power flow curve of the centrifugal fan increases with the increase of flow.When the fan operates at a constant speed, the operating point of the fan will move along the pressure flow characteristic curve.The operating point of the fan depends not only on its own performance, but also on the characteristics of the systemresistanceAs it increases, the pipeline performance curve will become steeper.The basic principle of fan regulation is to obtain the required working conditions by changing the performance curve of the fan itself or the characteristic curve of the external pipe network.[8]
With the continuous development of science and technology, AC motor speed control technology is widely used.Through a new generation of fully controlled electronic componentsFrequency converterchangealternating current dynamoTo control the flow of the fan by means of rotating speed of, can greatly reduce the energy loss caused by the previous mechanical way of regulating the flow.Energy saving principle of frequency conversion regulation:[8]
It can be seen that when its speed decreases to the originalRated speedAt half of, the flow, pressureShaft powerThey are reduced to 1/2, 1/4 and 1/8 respectively, which is why the frequency conversion adjustment mode can greatly save power.According to the characteristics of frequency conversion regulation, forSewage treatment processMedium, aeration tank always keeps 5m normallevelThe blower is required to conduct a wide range of flow adjustment under the condition of constant outlet pressure. When the adjustment depth is large, the air pressure will drop too much, which cannot meet the process requirements.When the adjustment depth is small, it does not show the advantages of energy saving, but makes the device complex and one-time investment increased.[8]
Regulating principle and characteristics of inlet guide vane[8]
The inlet guide vane regulating device means that a group of guide vanes with adjustable angle - inlet guide vanes are installed near the suction inlet of the blower. Its function is to rotate the air flow before entering the impeller, causing twisting speed.Guide vaneIt can rotate around its own axis. Each rotation angle of the blade means changing a guide vane installation angle, so that the direction of the air flow entering the fan impeller changes accordingly.[8]
Principle of inlet guide vane regulating air volume[8]
When the guide vane installation angle θ=0 °, the guide vane basically has no effect on the inlet air flow, and the air flow will flow into the impeller blade in a radial direction.When θ>0 °, the inlet guide vane will deflect the absolute velocity of the air flow inlet along the circumferential velocity direction by θ angle, and at the same time, it has a certain throttling effect on the velocity of the air flow inlet. This pre rotation and throttling effect will lead to the decline of the fan performance curve, thus changing the operating conditions and realizing the flow regulation of the fan.Energy saving principle of inlet guide vane regulation.[8]
When the installation angle of inlet guide vane increases from θ 1=0 ° to θ 2 or θ 3, the operating condition point moves from M1 to M2 or M3;The flow decreases from Q1 to Q2 or Q3;The shaft power is reduced from P ′ 1 to P ′ 2 or P ′ 3.The area represented by the section line is the power saved by the inlet guide vane compared with the throttling regulation.The depth of aeration tank is fixed, and the blower adjusts the flow under the condition of keeping the outlet pressure constant, that is, H=constant,When Q=variable, the characteristic curve of the pipe network is approximate to a horizontal straight line. The blower adopts inlet guide vane for adjustment. It is not necessary to change the characteristic curve of the pipe network. The pressure flow performance curve of the fan can be changed by changing the opening and closing angle of the guide vane. The flow change is achieved by moving the operating point to the new changed characteristic curve of the fan.[8]
The centrifugal fan adopts the inlet guide vane adjustment mode, which can achieve high efficiency and a wide performance range when operating under partial load. Under the condition of keeping the outlet pressure constant, the working flow can vary from 50% to 100% of the rated flow.The greater the adjustment depth, the more work saved.If the flow is reduced to 60% of the rated flow, the inlet guide vane mode ratioInlet throttling modePower savings of up to 17%.In addition, it has a relatively simple structure, reliable operation, convenient maintenance and management, and low initial investment.Therefore, the blower adopts inlet guide vane to regulate the flow, which is obviously the best regulation mode.[8]
Operation
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The operator must be familiar with this procedure before starting the machine and operate the blower in strict accordance with this procedure.[9]
(1) Check the lubricating oil level of the oil tank, which should be between the upper and lower limits of the oil dipstick.[9]
(2) Inform the substation to supply power to the machine.[9]
(3) Check the on-board control cabinet for alarm display. If there is an alarm, find out the cause and eliminate it[9]
(4) Select the "Manual" status.(Touch the "Manual" key with your finger).[9]
(5) Check whether the pressure relief valve is in the open position (the green light of the pressure relief valve is on).Check that the diffuser should be at the minimum opening (the minimum green light of the diffuser is on).[9]
After the above inspection and confirmation that the fan can be started, press the start button, and the blower will enter the start procedure:[9]
(1) Prelube the auxiliary oil pump for one minute (the green light of the auxiliary oil pump is on).
(2) The blower can start to run (the green light of the blower is on).[9]
(3) The pressure relief valve is slowly closed (the green light is off when the pressure relief valve is opened, and the green light is on when the pressure relief valve is closed two minutes later).[9]
(4) The auxiliary oil pump stops running (the green light for auxiliary oil pump running is off, and the red light for stop is on).So far, the blower has been successfully started and can be put into formal operation.[9]
(5) If the blower fails to start as scheduled after pressing the start key, the low oil pressure alarm red light will light up one minute later, and the whole starting process will stop.After finding out the cause and solving it, eliminate the alarm and restart.[9]
After the fan is started, the opening of the diffuser can be adjusted slowly according to the production needs. The diffuser can be controlled with the "ON" key and the "OFF" key to ensure the necessary air volume.[9]
When the fan is running, the fan must be monitored frequently, and attention must be paid to the fan's current, oil temperature, oil pressure, air inlet vacuum, sound, fan, temperature, vibration, etc.Make records on time. In case of any abnormality, find out the cause and eliminate it in time, and report to the production department. If necessary, take emergency shutdown measures (use cautiously).[9]
When a fan is stopped due to production, maintenance or repair needs:[9]
(1) Reduce the diffuser opening to the minimum (the diffuser minimum indicator green light is on).[9]
(2) Touch the "Stop" button of the fan with your finger to start the shutdown procedure.[9]
Product use
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The blower is mainly composed of the following six parts: motorAir filterBlower bodyAir chamberBase (also used as oil tank) and oil drip nozzle.The blower operates eccentrically by the rotor offset in the cylinder, and allows the volume change between the blades in the rotor slot to suck in, compress and discharge air.Using the blower'sPressure differenceAutomatically send lubrication to the oil drip nozzle and drip into the cylinder to reduce friction andNoiseAt the same time, it can keep the gas in the cylinder from returning. This kind of blower is also called sliding vane blower.The blower conveys medium to clean air, clean gassulfur dioxideAnd othersinert gasMainly.It can also produce and transport other flammable, explosive, corrosive, toxic and special gases as required.[10]
Energy saving transformation
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At present, among all kinds of mechanical and electrical equipment in all walks of life in China, the motors matched with fans account for about 60% of the installed capacity of national motors, and the power consumption accounts for about one-third of the total power generation in China.It is particularly worth mentioning that most fans have the phenomenon of pulling a cart from a horse during use. In addition, due to changes in production and process, it is necessary to frequently adjust the gas flow, pressure, temperature, etc;At present, many units still adopt the backward way of adjusting the opening of the air baffle or valve to adjust the flow, pressure, temperature, etc. of the gas.In fact, this is to meet the requirements of process and working conditions for gas flow regulation by artificially increasing resistance at the cost of wasting electric energy and money.This backward regulation mode not only wastes valuable energy, but also has poor regulation accuracy, which is difficult to meet the requirements of modern industrial production and services, and has serious negative effects.[11]
In recent years, with the rapid development of power electronics technology, computer technology and automatic control technology, electric drive technology is facing a historical revolution, that is, AC speed regulation replaces DC speed regulation and computer digital control technology replaces analog control technology has become a development trend.The AC variable frequency speed regulation technology of motor is a main means to save electricity and improve the process flow to improve product quality and environment and promote technological progress.[11]
