Selection and application of fan performance (I) Description of fan performance: 1. № 10, 12, 16, 20 are converted according to dimensionless performance of № 10 model. 2. № 5, 6, 8 are converted according to dimensionless performance of № 5 model. 3. № 5 and below shall be determined according to the performance of the measured prototype. Note: According to the dimensionless performance curve conversion formula, total pressure H=ρ u2 H (Pa) flow Q=900 π D22 uQ (m3/h) shaft power N=N × D22u3 ρ/4000 (kw), where D2 - impeller outer diameter (m) u - impeller outer edge linear speed (m/s) ρ - gas density (Kg/m3), the required power rate shall be based on shaft power plus mechanical loss and motor reserve. 4. The solid line is № 5 model, and the dotted line is № 10 model. The performance of the fan is expressed by the flow, total pressure, main shaft speed, shaft power, efficiency and other parameters of the fan, and there are certain relationships between the parameters, which are listed in the following table. The relationship of fan performance parameters changes density ρ, speed n changes speed n, atmospheric pressure P, gas temperature t Q1/Q2=n1/n2 H1/H2=(n1/n2) 2 ρ 1/ρ 2 N1/N2=(n1/n2) 3 ρ 1/ρ 2 η 1=η 2 Q1/Q2=n1/n2 H1/H2=(n1/n2) 2 (P1/P2) (273+t2/273+t1) N1/N2=(n1/n2) 3 (P1/P2) (273+t2/273+t1) η 1=η 2 Note: 1. In the middle, Q represents flow (m3/h), H represents total pressure (Pa), N represents shaft power (kw), η represents full pressure efficiency, ρ represents density (kg/m3), t represents temperature (℃), n represents speed (r/min), and P represents atmospheric pressure (Pa). 2. The footnote symbol 2 indicates the known performance and related parameters, and the footnote symbol 1 indicates the required performance and related parameters. （

Ezhou major 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 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 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. major 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.

Centrifugal fan company The work starts before the fan is used. one Ezhou Centrifugal fan company Carefully read the fan operation instructions and product samples, and be familiar with and understand the fan specifications, forms, impeller rotation direction and air flow in and out direction; Check whether all parts of the fan are in good condition again, or they can be installed and used only after being repaired. 2. The fan must be installed with safety devices to prevent accidents, and installed and wired by professionals familiar with relevant safety requirements. 3. The air duct connecting the inlet and outlet of the fan has separate support, and it is not allowed to add the overlapping weight of the duct to the components of the fan; When installing the fan, pay attention to the horizontal position of the fan, and adjust the connection between the joint surface of the fan and the foundation and the air outlet pipe to make it coincide naturally. Forced connection is not allowed. four major Centrifugal fan After the fan is installed, move the impeller by hand or lever to check whether it is too tight or rubbed, and whether there is any object that hinders the rotation. The test run can be carried out only when there is no abnormal phenomenon. The exposed part of the fan transmission device should be equipped with a protective cover (provided by the user). If the fan inlet is not connected, a protective screen or other installation device (provided by the user) should also be added. 5. The power distribution control box of the fan must match the corresponding fan (power, voltage, pneumatic mode, control mode, etc.). 6. The fan wiring should be made by a professional electrician, and the wiring must be correct and reliable. Especially, the wiring number at the electric control box should be consistent with the number on the fan terminal. The fan shell should be reliably grounded. The grounding must be reliable, and zero connection cannot be used instead of grounding. 7. After all fans are installed, check whether there are any left tool box sundries inside the fan

The wet electrostatic precipitator is a new kind of dust removal equipment used to treat micro dust and micro particles, major 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, Ezhou 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