Air compressor noise mainly comes from four parts: air inlet, exhaust port, mechanical port and electromagnetic port. Therefore, we can reduce the noise of the air compressor as long as the noise management of these four parts is carried out.
- 1. Reduce the noise of air compressor inlet and outlet
Fixed air compressors are usually installed indoors on the ground, but the air inlet of the compressor is either indoors or outdoors. When the air inlet of an air compressor is indoors, the noise of the air inlet should be reduced to a level slightly lower than that of the machine body, and the muffling volume of the air inlet muffler should be around 15 dB (A); when the air inlet of an air compressor is outdoors, the noise of the air inlet of the air compressor should be reduced to the requirements of environmental noise standards according to the environmental conditions around the machine room, and the muffling volume of the muffler should generally be above 20 dB (A). In order to ensure the muffling effect of the muffler, the inlet muffler should generally adopt resistant muffler without fiber, foam and other loose materials, resistant micro-perforated plate composite muffler or micro-perforated plate muffler, etc.
- 2. Reduce the noise treatment of the exhaust port of air compressor
Air compressors with high exhaust pressure and high flow rate produce high exhaust noise, so special mufflers need to be installed in the exhaust system for control. The muffler at the exhaust port should have a large muffling volume and a wide muffling frequency band, and has the function of pressure reduction and expansion, reducing the pressure difference between exhaust and emptying, so as to reduce the noise of exhaust and emptying.
For air compressors with a flow rate less than 20 m3/min, the noise is not high and mainly high frequency, generally resistive mufflers can be used. The advantage of muffler resistance muffler is that it can muffle sound in a wide range of medium and high frequencies, especially for high frequency sound waves.
- 3.Reduce the body noise of air compressor
To control the body noise and motor noise of air compressors, the control technology of sound insulation and sound absorption is often considered. The measure is to install a sound insulation cover or a sound insulation room for the compressor to stop the spread of noise.
In order to improve the sound insulation effect of the enclosure, an acoustic layer is usually attached to it.
- 4.Reduce the vibration noise of the air compressor body
To control air compressor noise, vibration must be controlled. The vibration of an air compressor is mainly transmitted outwards through the foundation and piping system. Vibration control is mainly through vibration isolation. The main measures are as follows.
① Use of vibration isolators. Vibration isolators form an elastic link between the air compressor and the foundation, reducing the amplitude to achieve vibration isolation, which is the most critical link for vibration isolation.
②The use of vibration isolation joints suspended foundation. The vibration isolation joints suspend the foundation and cut off the path of vibration transfer from the air compressor to the soil. The vibration isolation joints are 150-200 mm wide, filled with dry sand, and paved with dry sand and industrial felt underneath the foundation, with a felt thickness of 20-40 mm.
③Use of vibration isolation trenches. In some cases, trenches can be dug in the ground to cut off the surface wave-based vibrations that travel along the ground.
