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标题：Minimization of Cavitation in Centrifugal Pump by Using N.P.S.H
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作者：Taruranjan ; Shashank Mishra ; Arjun Kundu 等
期刊名称：International Journal of Innovative Research in Science, Engineering and Technology
印刷版ISSN：2347-6710
电子版ISSN：2319-8753
出版年度：2016
卷号：5
期号：6
页码：10274
DOI：10.15680/IJIRSET.2015.0506144
出版社：S&S Publications
摘要：Cavitation represents one of the most common faults in pumps and could potentially lead to a series offailures in mechanical seal, impeller, bearing, shaft, motor, etc. In this work, an experimental rig was setup toinvestigate cavitation detection using NPSH method, and measured parameters including sound, pressure and flow ratefor feasibility of cavitation detection. The cause of cavitation in pumps is usually due to insufficient NPSH (NetPositive Suction Head) energy on the suction side of the pump. NPSH is the energy required to push the liquid into thepump. Always calculate the NPSHa (Net Positive Suction Head available) from the system, and compare it with theNPSHr (Net Positive Suction Head required) by the pump. The NPSHa should always be one to two feet above theNPSHr of the pump to prevent cavitation. The NPSHr is a function of the pump design and cannot be changed. TheNPSHa is a function of the system parameters and can be changed. Included in the NPSHa is the atmospheric pressure,vapor pressure of the liquid being pumped, static height from the water level to the pump, and friction losses. Theatmospheric pressure is related to the altitude. At higher altitudes, the atmospheric pressure is less and subsequentlythere is not as much energy available to push the liquid into the pump. The vapor pressure varies by the type of liquidand the temperature of the liquid. If the liquid is allowed to cool before the pump, it can often be pumped easier.Regarding the static height from the fluid level to the pump, it is often possible to move the pump closer to the fluid toincrease the NPSHa. To reduce the friction losses, larger diameter pipes can often be employed to increase the NPSHaand thus prevent pump cavitation. If it is not possible to increase the NPSHa as described above, then the pump usershould search for a larger pump or pump that runs at a lower speed with lower NPSHr.
关键词：NPSH; Cavitation; Centrifugal Pump; Vapour presuure etc.