（3） The main faults and causes of the fan may occur during the operation of the fan. For the faults generated, the causes must be quickly identified and solved in time to prevent accidents. Faults in the Operation of 4-72-12 Centrifugal Fan and the Causes Table Fault Name Causes Severe Vibration of Bearing Box 1. The fan shaft is different from the motor shaft, and the coupling is installed askew. 2. The casing or air inlet rubs with the impeller. 3. The foundation stiffness is not enough or firm. 4. Impeller rivet is loose or wheel disc is deformed. 5. The impeller shaft disk and shaft are loose, and the coupling bolt is movable. 6. The connection between casing and bracket, bearing box and bracket, bearing box and seat is loose. 7. The air inlet and outlet pipes of the fan are poorly installed, causing vibration. 8. The rotor is unbalanced. Bearing temperature rise is too high 1. The bearing box vibrates violently. 2. The lubricating grease is poor in quality, deteriorated or overfilled, or contains dust, sand, dirt and other impurities. 3. The tightening force of connecting bolts of bearing cover seat is too large or too small. 4. The shaft and rolling bearing are installed askew, and the front and rear bearings are not concentric. 5. The rolling bearing is damaged. The motor current is too high and the temperature rise is too high. 1. The throttle valve in the air inlet pipe is not closed tightly when driving. 2. The flow exceeds the specified value, or the air duct leaks. 3. The gas density conveyed by the fan is too high. 4. The input voltage of the motor is too low or the power supply is cut off individually. 5. The coupling is improperly connected, the leather ring is too tight or the gap is uneven. 6. Affected by the violent vibration of the bearing box. 7. Affected by deterioration or failure of parallel fans. When the belt slides down, the two pulleys are not in the same plane with each other. Belt runout The distance between two pulleys is too close or the belt is too long.

3. When installing Type C and Type B, ensure that the two pulley positions are on the same plane, and the flatness tolerance is 0.5mm. 4. When installing Type D, use a dial indicator and feeler gauge to measure the coaxiality of the fan spindle and motor spindle and the parallelism of both ends of the coupling. The coaxiality tolerance of two shafts is 0.2mm, the parallelism tolerance of both ends of the coupling is 0.2mm, and the spacing between two planes of the coupling is 5 to 8mm. 5. After the fan is installed, move the rotor with hand or lever to check whether it is too tight or collided. The test run can be carried out without overtightening or collision. 6. After the motor is installed, the belt pulley or coupling guard shall be installed. If the air inlet is not connected to the air inlet pipe, the guard net or other safety devices (provided by the user) shall also be provided. 7. Other parts shall be installed according to the corresponding positions in the drawing. 8. 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.

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.

（1） Wet dust collector 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 dust collector 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） Zibo Wet dust collector 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.

Wet dust remover is an equipment that uses the action of water or other liquids and dusty gas to remove dust particles. When dust particles meet with sprayed water droplets, water films or wetted walls and devices, wetting, condensation, diffusion and sedimentation will occur, thus separating them from the gas to purify the gas. Zibo Wet dust collector Price It is characterized by both dust purification and gas purification, large Wet dust collector When the flue gas contains combustible components, the use of wet dust collectors can avoid equipment explosion, and the dust removal effect can generally meet the environmental protection requirements. The equipment is small and the investment is relatively low. Therefore, there are three wet dust collectors used in dust removal projects in mining, metallurgy, machinery, light industry, building materials and other industries. Sludge containing sewage must be treated, otherwise secondary pollution may occur, Therefore, it is not widely used as dry dust collector. There are many types of wet dust collectors. According to their structures, there are the following types: ① gravity spray wet dust collectors - spray scrubbing towers; ② Cyclone wet dust collector - cyclone water film dust collector, water film dust collector; ③ Self excited wet dust collector - impulse dust collector, water bath dust collector; ④ Packed wet dust collector - packed tower, turbulent ball tower; ⑤ Foam wet dust collector - foam dust collector, cyclone dust collector, leaky plate tower; ⑥ Venturi wet dust collector - Venturi tube dust collector; ⑦ Mechanical induction wet dust collector - water wheel dust collector.