I. SOURCE analysis:
Fan is divided into axial flow type, centrifugal type, mixed flow type and other models. Widely used in industrial and mining enterprises, civil building wall ventilation, job supply wind, pipe ventilation, roof ventilated, in the chemical industry, light industry, food, medicine, metallurgy, power plants and other industries and civil buildings in a large number of use.
Its noise is mainly aerodynamic noise, in which the noise of centrifugal blower is mainly low frequency, and it decreases with the increase of frequency.
Noise control is divided into sound source governance and transmission path governance. The former mainly on the fan impeller, Blade, shell, supporting structure and materials used to improve, in order to reduce the fan's own noise, the latter mainly using muffler, sound insulation cover, sound-absorbing wall and other noise control products from the fan noise transmission path to control the blower noise.
Second, noise control measures:
1. Installing the muffler on the inlet and outlet pipe of blower
2, in the fan unit plus the sound insulation cover
3. Adopt the comprehensive control measures of the fan room.
If there is a special fan room, it can be combined with the scene of the fan housing reform caused by sound insulation between the noise reduction method, that is, the wind machine unit closed in the room to make its noises, so the noise in the room is large, but the outside noise is much smaller. Seal the room to set into, exhaust air system, while equipped with muffler devices, for the ventilator suction and motor, casing and other cooling needs.
When the noise control requirements are high, the mechanical noise, vibration and electromagnetic noise of the unit can be comprehensively integrated with the measures of vibration reduction, base vibration isolation, sound absorption and sound insulation, in order to obtain satisfactory noise reduction effect.