The fan is allowed to start at full voltage or at reduced voltage, but it should be noted that the current at full voltage starting is about 5~7 times the rated current, and the reduced voltage starting torque is proportional to the square of the current. When the grid capacity is insufficient, the reduced voltage starting should be used. (When the power is greater than 11KW, it is advisable to adopt the step-down starting.) When the fan is in test run, FRP fan company Carefully read the product manual and check whether the wiring method is consistent with the wiring diagram; Carefully check whether the working voltage of the power supply to the fan meets the requirements, whether the power supply is out of phase or in phase, and whether the capacity of the electrical components provided meets the requirements. During commissioning, the number of people shall not be less than two. One person shall control the power supply and the other person shall observe the operation of the fan. If any abnormality is found, stop the machine immediately for inspection; First, check whether the rotation direction is correct; After the fan starts to run, immediately check whether the running current is balanced and whether the current exceeds the rated current; major FRP fan If there is no normal phenomenon, stop the machine for inspection. After five minutes of operation, stop the machine to check whether the fan is abnormal, and start the machine again after confirming that there is no abnormal phenomenon. When the two speed fan is tested, start the low speed fan first and check whether the rotation direction is correct; When starting the high-speed train, the fan must be stopped before starting to prevent the switch tripping and motor damage caused by high-speed reverse rotation. When the fan reaches the normal speed, check whether the input current of the fan is normal, and the operating current of the fan cannot exceed its rated current. If the operating current exceeds its rated current, check whether the voltage supplied to the fan is normal. The motor power required by the fan refers to the higher power required for centrifugal fan and fan box when the air inlet is fully open under certain working conditions. If the air inlet is fully opened for operation, the motor may be damaged. During fan commissioning, it is better to close the valve on the inlet or outlet pipeline of the fan, open the valve gradually after operation until the required working condition is reached, and pay attention to whether the operating current of the fan exceeds the rated current

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.

Correct maintenance is an important guarantee for the safe and reliable operation of the fan and the improvement of its service life. Therefore, FRP fan company When using fans, full attention must be paid. Impeller maintenance: at the initial stage of impeller operation and during all regular inspections, whenever there is an opportunity, the impeller must be checked for cracks, wear, dust and other defects. The impeller must be kept clean whenever possible, major FRP fan The steel wire brush shall be used regularly to remove the dust and rust on the impeller. As the travel time increases, the dust can not be evenly attached to the impeller, which will cause damage to the balance of the impeller and even cause rotor vibration. As long as the impeller is repaired, it needs to be dynamically balanced again. If possible, the portable trial dynamic balancing instrument can be used for on-site balancing. Before dynamic balancing, check whether all fastening bolts are tightened. Since the impeller has been operating in an unbalanced state for a period of time, these bolts may have become loose. Bearing maintenance: frequently check the oil supply of bearing lubricating oil. If the box leaks oil, tighten the bolts of the end cover a little. If this is not enough, you may have to use new sealing packing. When the bearing lubricating oil is in normal use, it should be replaced at least once every six months. When it is used for the first time, it should be done after 200 hours of operation. The second oil change should be done in 1 to 2 months. After that, the lubricating oil should be checked once a week. If the lubricating oil does not deteriorate, the oil change can be extended to 2 to 4 months. The specified brand of lubricating oil (specified on the general drawing) must be used when replacing, The old oil in the oil tank shall be completely drained and cleaned before new oil can be filled. If the fan bearing needs to be replaced, pay attention to the following matters: before installing the new bearing, the bearing and bearing box must be very clean. Place the bearing in the oil with a temperature of about 70~80 ℃ and heat it before installing it on the shaft. Do not force assembly to avoid damaging the shaft. Maintenance of other supporting equipment: see the respective user manual for the maintenance of various supporting equipment, including motors, electric actuators, instruments, meters, etc. These operating instructions are provided by each supporting manufacturer. The manufacturer will pack these instructions together and provide them to the user

Preparations for fan installation. major FRP fan Before unpacking the fan, check whether the package is intact, whether the nameplate parameters of the fan meet the requirements, and whether all accompanying accessories are complete. Carefully check whether the fan is deformed or damaged during transportation, whether the fasteners are loose or fall off, and whether the impeller is scratched, and check all parts of the fan. Qingdao FRP fan company If any abnormality is found, it shall be repaired before use. Use a 500V megger to measure the insulation resistance between the fan housing and the motor winding. The value should be greater than 0.5 megohm. Otherwise, the motor winding should be dried. The temperature during drying should not exceed 120 ℃. Prepare various materials, tools and sites required for fan installation.

Forecast the demand structure from the main fields. major FRP fan General ventilation fans (generally small and medium-sized centrifugal and axial fans) are the most widely used, with the largest demand and the largest number of manufacturers. In general, the supply of such products exceeds the demand. Although the demand for special purpose fans (including anti-corrosion fans, high-temperature fans, wear-resistant fans, fire smoke exhaust fans, etc.) is not large, due to the special operating environment, they need to be treated differently, because the main material requirements are special. The biggest feature of Roots blower is that when the pressure is adjusted within the allowable range, the flow changes little, the pressure selection range is wide, and it has the characteristics of forced gas transmission. The main disadvantage is that the noise is large. FRP fan company Through technology introduction, joint venture and self-development, China has launched a three blade roots blower with low noise, which is very popular with users and has a good market prospect. Turbine compressor (including centrifugal compressor, axial compressor and axial centrifugal compound compressor) is an important equipment of major engineering complete equipment, which plays an important role in the national economy. The performance of turbine compressor requires high pressure and large flow. With the large-scale of the complete set of equipment, the turbine compressor parameters are required to be higher and higher. Such as blast furnace smelting plant, large coal chemical plant, large fertilizer plant, large ethylene plant, large air separation plant, natural gas pipeline transportation plant and oil field gas injection plant. The demand for such products accounts for a small proportion of the total fan volume, but because of their importance, complex structure, long manufacturing cycle and high technical content, they have relatively good economic and social benefits. Turbine compressor manufacturing level represents the overall level of the fan industry

（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.