Pump Cavitation

Feedwater is supplied into steam boiler by boiler feed pump. In the operation of boiler feed pump, there is possibility some event may occur which cause damage pump parts. One of these cases is pump cavitation.

Pump cavitation is the formation events of steam or vapor bubbles within the liquid caused by the drop in fluid pressure to below the saturated vapor pressure of liquid at the operating temperature of the pump.

Vapor bubbles are formed in this process has a very short cycle. Knapp (Karassik et al, 1976) found that the starting formation of the bubble until the bubble burst only takes about 0.003 seconds. These bubbles will be carried by the flow of fluid until and finally these bubbles are in the region that has a greater pressure than the saturated vapor pressure of liquids.

In that area, the bubble will burst and will cause the shock to wall nearby of pump. The liquid will enter suddenly into the room which are formed due to the rupture of vapor bubbles was causing the collision. This event is called as pump cavitation and will cause mechanical damage to the pump.
Figure 1: Pump Cavitation

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