Study On The Control Of Noise And Vibration Inminitype Seawater Pumping System

Pumps and valves in seawater piping system can cause flow pulsation and generate serious noises.Hence,it is necessary to install the muffler in the piping system to effectively restrain the transmission of the vibration and noise.The subject is the vibration and noise of small caliber pipes full of liquid.And the following works are detailed in this paper.The structural strength and the acoustic performance of the expansion chamber muffler and the resonance muffler are accomplished.Considering the sealing factor of the pipeline and the muffler's application,this paper sets up a testing system for small caliber muffler,and carries out the experiments.Based on the results and experience got from previous works,the structure design and experimental study of the bladder type muffler are accomplished.Afterwards,bladder type muffler was redesign,and the corresponding noise and vibration characteristics of the bladder type muffler with bellows were carried out.From the theoretical analysis,structural design and analysis of acoustic simulation of the silencer with expansion chambers it can concluded that the resonant silencer do not performance well on controlling the pressure pulsation due to narrow-band resonance.After designing the bladder type muffler,finite element simulation was utilized to calculate structural strength,and experimental study was carried out to test the performance of the muffler under different pressure.By changing the pump motor frequency,the muffler's performance at specific frequency was explored.It is found out that the bladder type muffler has a satisfying effect on controlling the piping pressure fluctuation in rather wide frequency range.Pressure pulsation attenuation effect achieving its peak at the bladder pressure is close to the piping one.This paper designed a special muffler which installed bellows into the shell side.By the expansion and compression of bellows,it could isolate the vibration.Experimental results shows that such a muffler could achieve well sound attenuation effect on piping vibration and corresponding noise.