2. The influence of the total pressure deviation Δ H of the fan itself was not considered during selection. When the actual total pressure of the fan was positive deviation, the flow increased; When the actual total pressure of the fan is negative deviation, the flow decreases. See (a) below. The relationship between the deviation of the pipe network characteristic curve and the total pressure and the flow can be eliminated by one of the following methods when the fan starts to officially operate after new installation, or when the flow is too large or too small during use. 1. Use the opening and closing of throttling device to adjust the flow. 2. Increase or decrease the flow by increasing or decreasing the fan speed. 3. Use a new fan with higher or lower pressure to increase or decrease the flow. 4. Change the pipe network to reduce the resistance coefficient of the pipe network to increase the flow. It must be pointed out that throttling devices are generally used to regulate the flow. However, when the actual flow is much larger than the required flow, this method wastes too much power and is very uneconomical. If conditions permit, the fan speed is usually reduced or the fan with lower pressure is replaced. When the throttling device is fully open, the flow is still too small. At this time, the throttling device has lost its function, so try to reduce the resistance coefficient of the pipe network to increase the flow, or increase the fan speed and replace the fan with higher pressure. However, the speed of the fans directly connected to the motor and the coupling cannot be changed generally. Only the fan driven by the pulley can increase or decrease the speed by changing the diameter of the pulley, but the speed of the fan cannot exceed the speed max in the performance and selection table.

customized Centrifugal fan The wet electrostatic precipitator mainly has two structural forms. One is to use corrosion-resistant conductive materials (which can be non-metallic materials with excellent conductivity or metal materials with corrosion-resistant characteristics) as the dust collector, and the other is to use non-conductive non-metallic materials as the dust collector by forming a conductive water film through water spray or overflow. Wet electrostatic precipitators can also be divided into cross flow type (horizontal) and vertical flow type (vertical) according to the flow direction of waste gas. The cross flow type is mostly plate structure, Tongling Centrifugal fan The gas flows in and out in the horizontal direction, and the structure is similar to the dry electrostatic precipitator; The vertical flow type is mostly tubular structure, and the gas flow direction is vertical. Generally speaking, the efficiency of vertical flow wet electrostatic precipitator is twice as high as that of cross flow wet electrostatic precipitator under the condition of the same ventilation cross-sectional area. The dust deposited on the electrode plate can be washed down by water. Wet dust removal can avoid the re flying of captured dust and achieve high dust removal efficiency. Since there is no rapping device, the operation is also more reliable. The device that forms conductive film on the surface of the dust collector by means of water spray or overflow water has problems of corrosion, sludge and sewage treatment. It is only used when the dust concentration of the gas is low and the dust removal efficiency is required to be high; The wet electrostatic precipitator using corrosion-resistant conductive materials as dust collector does not need long-term water spraying or overflow water, Centrifugal fan manufactor Regular flushing is only carried out according to the operating conditions of the system, and only a small amount of water is consumed. This part of water can be recycled, and the dust collection system is basically free of secondary pollution.

The wet electrostatic precipitator is a new kind of dust removal equipment used to treat micro dust and micro particles, customized Centrifugal fan It is mainly used to remove dust, acid mist, water droplets, aerosols, odor, PM2.5 and other harmful substances in humid gases, and is an ideal equipment for controlling atmospheric dust pollution. The wet electrostatic precipitator is usually referred to as WESP, which has the same basic principle as the dry electrostatic precipitator. It goes through three stages: charging, collection and dust removal. The principle of wet electrostatic precipitator is the same as that of dry electrostatic precipitator, Tongling Centrifugal fan The dust is charged by high-voltage corona discharge, and the charged dust reaches the dust collecting plate/tube under the action of electric field force. The dry electrostatic precipitator mainly deals with dry gas with very low water content, while the wet electrostatic precipitator mainly deals with wet gas with high water content or even saturation. There is a big difference between WESP and DESP in the way of removing the dust collected on the dust collecting plate/pipe. The dry electrostatic precipitator generally uses mechanical rapping or acoustic cleaning to remove the dust on the electrode, while the wet electrostatic precipitator uses regular flushing to remove the dust along with the flow of flushing fluid

（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.

Tongling customized 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. Centrifugal fan manufactor 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 can not 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. customized 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.

Forecast the demand structure from the main fields. customized Centrifugal fan General ventilation fans (generally small and medium-sized centrifugal and axial fans) are the most widely used, with the largest demand and the largest number of manufacturers. In general, the supply of such products exceeds the demand. Although the demand for special purpose fans (including anti-corrosion fans, high-temperature fans, wear-resistant fans, fire smoke exhaust fans, etc.) is not large, due to the special operating environment, they need to be treated differently, because the main material requirements are special. The biggest feature of Roots blower is that when the pressure is adjusted within the allowable range, the flow changes little, the pressure selection range is wide, and it has the characteristics of forced gas transmission. The main disadvantage is that the noise is large. Centrifugal fan manufactor Through technology introduction, joint venture and self-development, China has launched a three blade roots blower with low noise, which is very popular with users and has a good market prospect. Turbine compressor (including centrifugal compressor, axial compressor and axial centrifugal compound compressor) is an important equipment of major engineering complete equipment, which plays an important role in the national economy. The performance of turbine compressor requires high pressure and large flow. With the large-scale of the complete set of equipment, the turbine compressor parameters are required to be higher and higher. Such as blast furnace smelting plant, large coal chemical plant, large fertilizer plant, large ethylene plant, large air separation plant, natural gas pipeline transportation plant and oil field gas injection plant. The demand for such products accounts for a small proportion of the total fan volume, but because of their importance, complex structure, long manufacturing cycle and high technical content, they have relatively good economic and social benefits. Turbine compressor manufacturing level represents the overall level of the fan industry