Due to low airflow velocity and small pressure variation, axial flow fans usually do not need to consider the change of gas specific capacity, that is, gas is regarded as unable to transmit fluid, widely used in factories, mines, dust removal, ventilation and other related fields. The design of flow rate is based on the requirement of large air volume, and its regulation mode is controlled by baffle, air valve, reflux, start and stop motor, etc., which can neither produce closed loop control nor consider the concept of energy. If the fan is to be adopted for a long time, the usual maintenance work is essential. Only periodic guarantees can prevent major problems. Basically, the environment should always be kept clean, the surface of the fan should be kept clean, and the inlet and outlet should be free of sundries. Regular cleaning of fan and pipe dust and other debris. Power-saving principle where the use of AC detection motor as an electric transmission mode of production machinery, in operation can not be full load operation, motor power according to the high load period kilowatt load selection. Motor full voltage, full speed work, but the load is very small, there will be a lot of time no load operation.