A centrifugal fan is a mechanical device that relies on input mechanical energy to increase air pressure and send air in parallel. This is a driven power machine. Centrifugal fans are widely used for ventilation, dust removal and cooling in factories, coal mines, tunnel construction, fiberglass cooling towers, vehicles, ships and buildings; ventilation and induced draft fans of heating furnaces and kilns; air conditioning purification equipment and home appliances Refrigeration and exhaust in equipment; drying and sorting of grains; inflating and promoting wind tunnel banquets and motorboats, etc.

The centrifugal fan is essentially a variable flow and voltage stabilizing device. When the speed ratio is constant, the theoretical pressure-flow curve of the centrifugal fan should be a straight line. The specific characteristic curve is kinked to take into account internal structural damage. The pressure often generated in centrifugal fans is greatly affected by changes in inlet temperature or density. For a known air intake volume, the working pressure generated when the air inlet temperature is large (the density of the air is low) is small. For a known load versus total flow characteristic curve, there will be an output power versus total flow characteristic curve. When the blower is operating at steady speed, for a known total flow rate, the required efficiency increases as the inlet temperature decreases.

The centrifugal fan is a piece of equipment with a complex structure, which mainly consists of an air inlet, an electric damper, an impeller, a motor, and a vent. In different situations, the functions of centrifugal fans are also different. Therefore, some operating conditions are inconsistent and the efficiency of the centrifugal fan will be affected. To adjust the centrifugal fan to the best condition, you can start from several levels.

1. The centrifugal fan allows the motor to be started with rated power or the blood pressure lowering electric type, but it should be noted that the current when the motor is started with rated power is about 5-7 times the rated voltage. The torque of the blood pressure lowering motor is positively related to the current square meter. When the power When volume is insufficient, hypotensive initiation should be used.

2. During the trial operation of the centrifugal fan, you should carefully read the product manual and check whether the wire connection method is consistent with the wiring method; carefully check whether the voltage of the fan switching power supply meets the standards, and whether the switching power supply is out of phase or out of phase. , whether the volume of the distributed electrical components meets the regulations.

3. There should be no less than two people during the trial operation. One person controls the power supply and the other observes the operating status of the fan. If any abnormality is found, immediately shut down the machine for inspection. First check whether the direction of rotation is correct. After the centrifugal fan gradually runs, the operating voltage of each phase should be checked immediately. Check whether the flow is balanced and whether the current exceeds the rated voltage; if there is any abnormality, shut down the machine and check. After running for five minutes, shut down the fan and check if there are any abnormalities. Make sure there are no abnormalities before starting the operation.

4. During the trial operation of the single-speed centrifugal fan, first start the low-speed gear and check whether the direction of rotation is correct; when starting quickly, you need to wait for the fan to come to a standstill before restarting to prevent rapid reverse rotation, which may trigger switch tripping and motor damage.

5. When the centrifugal fan reaches a normal speed ratio, the input current of the fan should be accurately measured to see if it is normal. The operating current of the centrifugal fan should not exceed its rated voltage. If the operating current exceeds its rated voltage, check whether the provided operating voltage is normal.

6. The motor power required by the centrifugal fan means that under certain circumstances, for the centrifugal fan and the fan box, the output power required to fully open the air inlet is relatively large. If the air inlet is fully opened and operated, the motor is at risk of damage. During the trial operation of the fan, try to close the gate valve at the fan inlet or inlet and outlet pipeline. After operation, gradually open the gate valve until it reaches the required working condition, and pay attention to whether the operating current of the fan exceeds the rated voltage.