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 total 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. （

Wet dust remover is a device that uses the action of water or other liquids and dusty gases to remove dust particles. When dust particles meet with sprayed water droplets, water films or wetted walls and devices The process of wetting, condensation, diffusion and sedimentation takes place, so it is separated from the gas to purify the gas. Dazhou Boiler fan Price It is characterized by purifying dust at the same time It can also purify gas, customized Boiler fan When the flue gas contains combustible components, the use of wet dust collectors can avoid equipment explosion, and the dust removal effect can generally meet the environmental protection requirements. The equipment is small and the investment is relatively low. Therefore, there are three wet dust collectors used in dust removal projects in mining, metallurgy, machinery, light industry, building materials and other industries. Sludge containing sewage must be treated, otherwise secondary pollution may occur, Therefore, it is not widely used as dry dust collector. There are many types of wet dust collectors. According to their structures, there are the following types: ① gravity spray wet dust collectors - spray scrubbing towers; ② Cyclone wet dust collector - cyclone water film dust collector, water film dust collector; ③ Self excited wet dust collector - impulse dust collector, water bath dust collector; ④ Packed wet dust collector - packed tower, turbulent ball tower; ⑤ Foam wet dust collector - foam dust collector Cyclone dust collector, leaky plate tower; ⑥ Venturi wet dust collector - Venturi tube dust collector; ⑦ Mechanical induction wet dust collector - water wheel dust collector.

Boiler fan Price Forecast from the characteristics of fan demand. customized Boiler fan For small and medium-sized fans with large usage and wide range, the product structure and manufacturing process are relatively simple, and the cost is also low. Users mainly pursue high efficiency, low noise, long life, and low price. The other is capital and technology intensive. The product structure is complex, the manufacturing cycle is long, and the completeness and systematicness are also strong. Moreover, it operates under high pressure, high temperature and high speed conditions, and some even operate under severe conditions. Users have different requirements for this type of fan. For turbine blowers, compressors and large ventilators, users mainly pursue high quality, high reliability, smooth operation and long cycle

The selection of fans Product performance and fan performance listed in the selection table are based on the performance of delivering air under standard conditions. Therefore, when the use condition is non-standard, the H4-72-12 centrifugal fan must convert the use performance into the performance under standard conditions according to the relationship in the table above, and then select according to the performance and selection table. （3） Treatment of excessive or insufficient flow During use, excessive or insufficient flow often occurs. There are many reasons for this phenomenon. If the flow is high and low during use, it is mainly because the resistance in the pipe network is high and low, or the fan works in a non working area. If it is gradually reduced after a long time during use, it is mainly due to pipe network blockage. After the fan is newly installed, the flow is too large or insufficient during the formal operation. The main reasons for this phenomenon are as follows: 1. The actual value of pipe network resistance is too different from the calculated value. In the general pipe network characteristic equation, H=KQ2, if the actual value K of K-resistance coefficient is less than the calculated value K, the flow will increase; If the actual value K is greater than the calculated value K, the flow decreases. See (b) below.

Forecast from domestic market capacity. Dazhou Boiler fan Price Fans vary greatly according to different pressure and flow requirements. Therefore, the fan demand should be differentiated according to its type and size, and predicted according to the demand of different industries. According to incomplete statistics, the annual average growth rate of national fan output was 13.8% from 1980 to 1996. customized Boiler fan It is estimated that the total output of wind turbines in China will be 2.6 million to 2.9 million in 2005 and 3.1 million to 3.25 million in 2010. According to the statistics of fan industry over the years, it is predicted that the output of centrifugal compressors will be 1.6 million to 1.8 million in 2005 and 2 million to 2.1 million in 2010; The output of axial compressor is 260000 in 2005, and is expected to reach 360000 in 2010; The market share of turbine compressor and blower will reach about 70% in 2005