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.
Boiler centrifugal fan company The work starts before the fan is used. one Xiangxiang Boiler centrifugal fan company Carefully read the fan operation instructions and product samples, and be familiar with and understand the fan specifications, forms, impeller rotation direction and air flow in and out direction; Check whether all parts of the fan are in good condition again, or they can be installed and used only after being repaired. 2. The fan must be installed with safety devices to prevent accidents, and installed and wired by professionals familiar with relevant safety requirements. 3. The air duct connecting the inlet and outlet of the fan has separate support, and it is not allowed to add the overlapping weight of the duct to the components of the fan; When installing the fan, pay attention to the horizontal position of the fan, and adjust the connection between the joint surface of the fan and the foundation and the air outlet pipe to make it coincide naturally. Forced connection is not allowed. four customized Boiler centrifugal fan After the fan is installed, move the impeller by hand or lever to check whether it is too tight or rubbed, and whether there is any object that hinders the rotation. The test run can be carried out only when there is no abnormal phenomenon. The exposed part of the fan transmission device should be equipped with a protective cover (provided by the user). If the fan inlet is not connected, a protective screen or other installation device (provided by the user) should also be added. 5. The power distribution control box of the fan must match the corresponding fan (power, voltage, pneumatic mode, control mode, etc.). 6. The fan wiring should be made by a professional electrician, and the wiring must be correct and reliable. Especially, the wiring number at the electric control box should be consistent with the number on the fan terminal. The fan shell should be reliably grounded. The grounding must be reliable, and zero connection cannot be used instead of grounding. 7. After all fans are installed, check whether there are any left tool box sundries inside the fan
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: The dimensionless performance curve is converted to the dimensioned calculation 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 - outer diameter of impeller (m) u - linear speed of outer edge of impeller (m/s) ρ— The power required for gas density (Kg/m3) 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 the 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 two 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 table, Q represents flow (m3/h), H represents total pressure (Pa), N represents shaft power (kw), η Is the total pressure efficiency, ρ Is density (kg/m3), t is temperature (℃), n is speed (r/min), P is 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. （
（1） Boiler centrifugal fan company The operating environment should always be kept clean, the fan surface should be kept clean, and the air inlet and outlet should be free of sundries. Regularly remove dust and other sundries in the fan and pipe. （2） customized Boiler centrifugal fan It can only be operated when the fan is completely normal. At the same time, it is necessary to maintain sufficient capacity of power supply facilities and stable voltage. Open phase operation is strictly prohibited. The power supply lines must be dedicated lines, and temporary lines should not be used for long-term power supply. (3) In case of abnormal sound, serious heating of motor, electrification of shell, tripping of switch, failure to start and other phenomena of fan during operation, the fan shall be stopped immediately for inspection. To ensure safety, maintenance is not allowed during the operation of the fan. After the maintenance, the test run shall be carried out for about five minutes, and the machine shall be restarted after confirming that there is no abnormal phenomenon. （4） Xiangxiang Boiler centrifugal fan company Replenish or replace lubricating grease for bearings irregularly according to the service environmental conditions (it is not necessary to replace lubricating grease for motor enclosed bearings within the service life). To ensure good lubrication of the fan during operation, the number of times of oiling shall not be less than 1000 hours/time. For enclosed bearings and motor bearings, fill 2/3 of the inner and outer rings of bearings with ZL-3 lithium based lubricating grease. It is strictly prohibited to run without oil. (5) The fan shall be stored in a dry environment to prevent the motor from moisture. Rain proof measures shall be taken when the fan is stored in the open air. The fan shall be prevented from collision during storage and handling to avoid damage to the fan.
customized Boiler centrifugal fan Fans can be divided into axial flow fans, centrifugal fans and diagonal flow (mixed flow) fans according to the flow direction after the airflow enters the impeller. Fans are divided into press in local fans (hereinafter referred to as press in 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 (hereinafter referred to as extraction fans) according to their purposes. Boiler centrifugal fan company Fans can also be divided into single-stage, two-stage or multi-stage pressurization fans according to the form of pressurization. For example, 4-72 is single-stage pressurization, and high-end fan is multi-stage pressurization fan. Fans can be divided into axial flow fans, mixed flow fans, roof fans, air conditioning fans, etc. Fan can be divided into negative pressure fan, low pressure fan, medium pressure fan and high pressure fan according to pressure. According to the outlet pressure (pressure rise), it can be divided into: ventilator (≤ 15000 Pa), blower (15-350000 Pa), compressor (≥ 350000 Pa)
Boiler centrifugal fan company Forecast from fan demand characteristics. customized Boiler 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
