9. Since the flow, total pressure, main shaft speed and shaft power of the fan have a fixed relationship, the main shaft speed should not be changed when the motor capacity does not change. If the main shaft speed increases, the motor may be burned due to overload. The motor power used by the fan refers to the power not required when the air inlet and outlet are fully open in terms of mechanical losses and due reserves under a specific mine. If the outlet or inlet of the fan is not connected to the pipeline or is idle without external resistance, the motor may also be burned out. For safety, a valve shall be added to the outlet or inlet pipeline of the fan, and it shall be closed when starting the motor. After turning, the valve shall be slowly opened until the specified working condition is reached, and attention shall be paid to whether the current of the motor exceeds the specified value. High power motors must be started in proper ways, such as voltage reduction, frequency conversion, etc.

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 Wet dust collector manufactor 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 Wet dust collector 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.

Yueyang Wet dust collector Classified by layers. There are many classification methods for fans, which can be roughly classified according to the following levels: (1) According to the level of pressure generated, they can be divided into: volumetric: reciprocating and rotary; Turbine type: centrifugal, axial flow, mixed flow and cross flow, jet type. Fan generally refers to turbine type, namely centrifugal, axial, mixed flow, cross flow and other forms. Its main characteristics are: centrifugal fan: higher pressure, but smaller air volume. Axial flow fan: higher air volume, but lower pressure. Mixed flow fan: the air volume and pressure are between centrifugal fan and axial fan. Horizontal fan: with high dynamic pressure, it can obtain flat airflow. (2) major Wet dust collector According to the different materials used, it can be divided into:; Iron shell fan (ordinary fan), glass fiber reinforced plastic fan, plastic fan, aluminum fan, stainless steel fan, etc. (3) According to the direction of gas flow, it can be divided into centrifugal type, axial flow type, diagonal flow type (mixed flow type) and cross flow type. (4) According to the flow direction of the airflow entering the impeller, it can be divided into axial flow fan, centrifugal fan and diagonal flow (mixed flow) fan. (5) Wet dust collector manufactor It can be divided into: press in local fans and flame-proof motors placed outside or inside the flow channel, and flame-proof motors placed inside the explosion-proof sealing chamber of the extraction type local fans. (6) According to the form of pressurization, it can also be divided into single-stage, two-stage or multi-stage pressurization fans

（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.