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. （

The selection basis of wet dust collector is as follows. ① large Centrifugal fan Dust removal efficiency. Whether the efficiency of wet dust collector is high or not is one of the most important performance indicators to be selected. Under certain conditions, the gas flow, specific dust pollutants, and the gas state have a direct impact on the collection efficiency. ② Operational flexibility. Centrifugal fan manufactor Any operating equipment shall consider its negative flow, and the impact on the capture efficiency when the air flow exceeds or is lower than the design value; Similarly, it is necessary to know how to operate when the dust concentration is unstable or continuously higher than the design value. ③ Hydrophobicity. The purification efficiency of wet dust collector for hydrophobic dust is not high, and generally it is not suitable for the operation at the design value. ④ Adhesion. Wet dust collector can purify cohesive dust, but flushing and cleaning shall be considered to prevent blockage, ⑤ corrosiveness. Anticorrosion measures shall be considered when purifying corrosive gas, ⑥ water consumption. How much water is consumed by the dust remover, sewage treatment and anti freezing measures for water in winter. ⑦ Mud treatment. Mud treatment is an inevitable problem for wet dust collectors, and efforts should be made to reduce the harm of pollution. ⑧ Operation and maintenance. Guigang Centrifugal fan manufactor Generally, moving or rotating parts inside the dust remover shall be avoided, and it shall be noted that if the gas passes through the channel section too small, it will cause blockage.

Centrifugal fan manufactor Forecast from the characteristics of fan demand. large Centrifugal 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

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. In particular, Centrifugal fan manufactor Most fans have the phenomenon of pulling a cart from a horse during use. In addition, due to changes in production and technology, it is necessary to frequently adjust the gas flow, pressure, temperature, etc; Many units still adopt the backward way of adjusting the opening degree of the wind shield or valve to adjust the gas flow, pressure, temperature, etc. 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. With the continuous improvement and development of frequency conversion technology in recent ten years. The performance of variable frequency speed regulation is becoming increasingly perfect, large Centrifugal fan It has been widely used in AC speed regulation in different fields. It has brought considerable economic benefits to enterprises and promoted the automation process of industrial production.