major Axial flow centrifugal fan The fan is a kind of driven fluid machinery, which relies on the input mechanical energy to increase the gas pressure and discharge gas. Fan is the abbreviation of Chinese custom for gas compression and gas transmission machinery. Generally speaking, fans include fans, blowers, and wind turbines. Wuhan Axial flow centrifugal fan company Fans are widely used for ventilation, dust discharge and cooling of factories, mines, tunnels, cooling towers, vehicles, ships and buildings, as well as ventilation and induced draft of boilers and industrial furnaces; Cooling and ventilation in air conditioning equipment and household appliances; Drying and delivery of grain, wind source of wind tunnel and inflation and propulsion of hovercraft

Wuhan major Axial flow centrifugal fan Fan performance parameters. The performance parameters of fan mainly include flow, pressure, power, efficiency and speed. In addition, the size of noise and vibration is also the main fan design index. Flow, also known as air volume, is expressed by the volume of gas flowing through the fan in unit time; Pressure, also known as wind pressure, refers to the pressure rise value of gas in the fan, including static pressure, dynamic pressure and total pressure; Power refers to the input power of the fan, namely shaft power. The ratio of effective power of fan to shaft power is called efficiency. Axial flow centrifugal fan company The total pressure efficiency of fan can reach 90%. Fans are widely used for ventilation, dust discharge and cooling of factories, mines, tunnels, cooling towers, vehicles, ships and buildings; Ventilation and induced draft of boiler and industrial furnace; Cooling and ventilation in air conditioning equipment and household appliances; Drying and selection of grain; Wind source of wind tunnel and inflation and propulsion of hovercraft. The working principle of the fan is basically the same as that of the turbine compressor, but because the gas flow rate is low and the pressure changes little, it is generally unnecessary to consider the change of gas specific volume, that is, treat the gas as an incompressible fluid

Wuhan major Axial flow centrifugal fan Forecasts from foreign markets. The member units of China General Machinery Fan Industry Association exported 7969 fans in 2000, with the export delivery value of 81.157 million yuan. From 1991 to 2000, the total number of exported fans was 72876, and the total value of export delivery was 747.26 million yuan. Axial flow centrifugal fan company The trend of global economic integration is becoming more and more obvious. The economies of all countries will further depend on each other. International economic cooperation and exchanges will become closer and closer. The international market is at a stage of significant intersection and integration. At the same time, the pace of global industrial restructuring is accelerating, and significant progress has been made in the scale and depth of international division of labor. Developed countries continue to shift industrial production to capital intensive and technology intensive industries, and labor-intensive products are transferred to developing countries and regions. This provides a good development opportunity for China to play its own advantages and enter the international market. Since the 1970s, China has introduced foreign advanced technology of centrifugal compressor, which has improved the product grade through digestion, absorption and innovation. As long as the quality and delivery time are guaranteed and the price advantage is used, it is competitive internationally. Especially after China's entry into WTO, it is entirely possible to increase the fan export. From the historical analysis, the main export varieties are small and medium-sized fans and fan accessories. The main gap between domestic enterprises producing such fans is that the surface quality cannot meet the export requirements. If the appearance quality is improved and the price is favorable, the prospect in the foreign market is broad. From 1991 to 2000, the fan exports of small and medium-sized fans were not stable enough, and there was no obvious growth trend. However, with the continuous progress of technology, it is expected that the export volume of such fans will continue to increase, and it is predicted that the annual average growth rate will be about 5% on the basis of 2000. major Axial flow centrifugal fan The export of centrifugal compressors and blowers increased significantly from 1991 to 2000, reaching 870000 sets in 2000. The main exporting countries are India, Pakistan, Iran, Vietnam and other developing countries. It is expected that this trend will continue to develop, reaching 1 million units per year.

Before installation, first prepare the materials and tools for installation, and check the parts of the fan, especially the impeller, main shaft, bearing and other parts. If any damage is found, repair it, and then clean the inside of the bearing box with kerosene. In the process of installation, the following points must be paid attention to: 1. In order to prevent rust and reduce the difficulty of disassembly, some grease or machine oil should be coated on some joint surfaces. 2. When installing the bolts on the joint surface, if there are positioning pins, install the pins and tighten them before tightening the bolts. 3. Check that there should be no tools and sundries falling or left in the casing and other casings. Installed and used by CHANG factory bridge QIAO ISO9001 quality management system certification enterprise of Beijing No. 2 Blower Works 1. When installing the fan, the inlet and outlet must be provided with soft connection, and the weight of the gas transmission pipeline should not be added to the casing. Correct the gap size between the air inlet and the impeller according to the drawing, and keep the shaft in a horizontal position. 2. When installing the soft connection of the air inlet, the bolts of the air inlet itself can be directly used for connection. At this time, the air inlet is fixed by three countersunk screws.

（3） The main faults and causes of the fan may occur during the operation of the fan. For the faults generated, the causes must be quickly identified and solved in time to prevent accidents. Faults in the Operation of 4-72-12 Centrifugal Fan and the Causes Table Fault Name Causes Severe Vibration of Bearing Box 1. The fan shaft is different from the motor shaft, and the coupling is installed askew. 2. The casing or air inlet rubs with the impeller. 3. The foundation stiffness is not enough or firm. 4. Impeller rivet is loose or wheel disc is deformed. 5. The impeller shaft disk and shaft are loose, and the coupling bolt is movable. 6. The connection between casing and bracket, bearing box and bracket, bearing box and seat is loose. 7. The air inlet and outlet pipes of the fan are poorly installed, causing vibration. 8. The rotor is unbalanced. Bearing temperature rise is too high 1. The bearing box vibrates violently. 2. The lubricating grease is poor in quality, deteriorated or overfilled, or contains dust, sand, dirt and other impurities. 3. The tightening force of connecting bolts of bearing cover seat is too large or too small. 4. The shaft and rolling bearing are installed askew, and the front and rear bearings are not concentric. 5. The rolling bearing is damaged. The motor current is too high and the temperature rise is too high. 1. The throttle valve in the air inlet pipe is not closed tightly when driving. 2. The flow exceeds the specified value, or the air duct leaks. 3. The gas density conveyed by the fan is too high. 4. The input voltage of the motor is too low or the power supply is cut off individually. 5. The coupling is improperly connected, the leather ring is too tight or the gap is uneven. 6. Affected by the violent vibration of the bearing box. 7. Affected by deterioration or failure of parallel fans. When the belt slides down, the two pulleys are not in the same plane with each other. Belt runout The distance between two pulleys is too close or the belt is too long.