The pump noise is mainly the aerodynamic noise generated by the gas/liquid during the transportation process, the structural noise excited by the vibration of the motor casing, the noise generated by the vibration of the machine base, and the noise of the motor. Such noise level peaks are mainly concentrated in the low octave band, which is in the range of approximately 100-450 Hz. The sound source is a steady-state noise when the pump room is operating normally. Pipeline noise is the noise generated when water flows through a pipe. In addition, the cavitation phenomenon of the pump and the water hammer phenomenon of the pump can also generate instantaneous noise. The noise generated by the water supply pipe is affected by the flow rate and pressure.

 

 The noise generated by the whole set of pumping facilities is mainly mechanical noise. At present, the method of controlling noise in acoustic principle is more commonly used to control the transmission of noise, mainly including sound insulation, sound absorption and noise reduction. Sound insulation is to separate the sound source from the sound receiving point by using sound insulation structure; sound absorption is to use noise absorption structure or sound absorption material to reduce noise; noise reduction is to use impedance, resistance, porous diffusion and other principles to reduce the noise value.

Noise control measures should make full use of the site environment and conditions based on acoustic principles. Such as: 

1. According to the pump room environment, the pump room with the sound source is not tightly sealed shall be soundproofed, and the room where the pump room generates noise shall be treated with sound absorption/sound insulation, and the doors and windows shall be soundproofed.

2. Control the noise generated by machine equipment and equipment parts. The pump base of the new pump house should be of heavy weight to prevent vibration from generating noise. Moreover, a rubber vibration isolating pad should be provided for vibration isolation to reduce vibration noise; each pump unit is separately provided with a foundation to prevent resonance. Use “soft” coupling as much as possible on the pump suction and pressure water pipes. Regular maintenance, problems such as water leakage, loose parts, equipment parts, mechanical vibration, etc. should be repaired in time to reduce noise.

Because different manufacturers and types of pumps, the working principle and structure will be different, so the site survey and analysis of the noise source is very important for the pump room noise reduction scheme design and material selection.