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. （

Centrifugal fan Price Different types of dust remover equipment have their own precautions. When we usually use the dust remover equipment, we should tell my customer friends some application matters. What matters should we consider when using wet electrostatic precipitator? Matters needing attention on the application of wet electrostatic precipitator. 1. The wet electrostatic precipitator shall be put into the insulator chamber electric heating and hot air purging system at least 8 hours in advance to ensure that the temperature of the insulator chamber is more than 60 ℃. 2. The wet desulfurization system of the wet electrostatic precipitator is put into operation early to prevent dry and high-temperature smoke from entering the wet electrostatic precipitator, which will lead to scaling of internal parts and damage of internal anti-corrosion coating. three customized Centrifugal fan The wet dust collector can be opened when the following three conditions are met together: 3.1 The wet electrostatic precipitator is operated with 25% of the oil gun remaining and 35% of the powder feeding is normal and stable or the oil gun is completely withdrawn. 3.2 The temperature of flue gas entering the wet electrostatic precipitator is lower than 70 ℃. 3.3 Desulfurization equipment has been opened. 4. The process of opening the wet electrostatic precipitator: first open the low-pressure water supply system and then the high-pressure power supply system.

In order to avoid man-made faults and accidents caused by improper maintenance, prevent the occurrence of natural faults and accidents of fans and motors in all aspects, so as to give full play to the efficiency of equipment and extend the service life of equipment, therefore, the maintenance of fans must be strengthened. （1） Working system of fan maintenance The fan maintenance personnel must pay attention to the following points: 1. The fan can only be operated when the fan equipment is completely normal. 2. If the fan equipment starts after maintenance, pay attention to whether all parts of the fan are normal. 3. Regularly clean the dust, dirt, water and other impurities inside the fan and gas transmission pipeline, and check whether the impeller is worn and rusted, if any, repair and replace it in time. 4. Regularly replace the lubricating oil (recommended 3-6 months). It is recommended to add N46 (ISO VG46, 30) in summer and N32 (ISO VG32, 20) in winter. The oil level should be at 1/2 of the oil window. 5. Regularly check (3-6 months is recommended) couplings, pulleys, etc. If parts are found to be worn or rusted, they should be repaired and replaced immediately. 6. The equipment shall not be repaired during operation.

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.

When the bearing temperature of the fan is normal, it is ≤ 70 ℃. If it rises to 70 ℃, an alarm should (will) be given if there is an electric control. At this time, the reason should be found out. First, check whether the cooling water is normal? Is the bearing oil level normal? If the cause cannot be found for a while, the bearing temperature rises rapidly to 90 ℃, and if there is an electric control, the alarm and shutdown signal shall be sent again. Henan Centrifugal fan In the process of fan startup, shutdown or operation, if any abnormal phenomenon is found, it shall be checked immediately. If any small fault is found during the check, it shall be timely found out the cause and eliminated. In case of major fault (such as severe vibration, impact of fan, sharp rise of bearing temperature, etc.), stop the machine immediately for inspection. customized Centrifugal fan The lubricating oil (or grease) shall be renewed and replaced one month after the first operation of the fan. In addition to replacement after each overhaul, the lubricating oil (or grease) can be replaced once every 1~2 months under normal conditions, or according to the actual situation. Fans include fans, turbine blowers, roots blowers and turbine compressors, which are divided into seven categories in detail, including centrifugal compressors, axial compressors, centrifugal blowers, roots blowers, centrifugal fans, axial fans and Ye's blowers