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. （

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. Hunan Wet dedusting equipment 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. large Wet dedusting equipment 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 7 categories in detail, including centrifugal compressors, axial compressors, centrifugal blowers, roots blowers, centrifugal fans, axial fans and Ye's blowers

（1） Wet dedusting equipment Price 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） large Wet dedusting equipment 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） Hunan Wet dedusting equipment Price 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.

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.