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. （
The key points of factors to be considered in the technical approach to the transformation of wet electrostatic precipitators: the wet electrostatic precipitators built before the mid-1970s could not meet the requirements of the new emission standards because of the low requirements for boiler smoke and dust emissions, the small selection of equipment capacity, the outdated structure of electrostatic precipitators, aging of dust removal equipment, low dust removal efficiency and other reasons, These electrostatic precipitators have a problem of transformation to further improve efficiency. major FRP fan Price The improvement measures for the original equipment should be considered from both technical and economic aspects, and the following technical approaches are generally adopted: 1. Discover the potential of electrostatic precipitator equipment. For example, adjust the rapping cycle and rapping force of the electrode to improve the corona power and reduce the re flying of dust; Improve the uneven distribution of flue gas velocity and readjust the technical parameters of the airflow distribution device; Adjust the control mode or power supply mode of the power supply equipment. 2、 major FRP fan Combination with other dedusting equipment. That is, a primary precipitator is added before or after the electrostatic precipitator. 3. Increase the capacity (or dust collection area) of the electrostatic precipitator. That is, add an electric field, or increase or widen the electric field of the electrostatic precipitator.
（2） Precautions for normal operation of fan 1. If the flow is found to be too large, which does not meet the operating requirements, or less flow is required in a short time, the throttling device can be used to adjust to meet the operating requirements. 2. The sensitivity of thermometer and oil pointer shall be checked regularly. 3. In case of any abnormal phenomenon during the start-up, shutdown or operation of the fan, it shall be checked in time. 4. For minor faults found in the inspection, find out the causes in time and try to eliminate or deal with them. If minor faults cannot be eliminated or major faults are found, repair them immediately. 5. In addition to replacing the lubricating oil during each maintenance, the lubricating oil shall also be replaced regularly. Observe the oil level at ordinary times and replenish lubricating oil in time.
Jinan major FRP 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. FRP fan Price 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 FRP 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.
The selection basis of wet dust collector is as follows. ① major FRP 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. FRP fan Price Any operating equipment It is necessary to take into account its negative circulation and the impact on the capture efficiency when the air flow rate 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. Jinan FRP fan Price 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.
