What is the cavitation of a centrifugal pump?

What is the cavitation of the centrifugal pump? Liquid at the impeller inlet flow rate increases, the pressure is lower than the working temperature of the corresponding saturation pressure, will cause a part of the liquid evaporation (ie vaporization). Evaporation of the bubble into the higher pressure areas, the pressure suddenly condensed, so the liquid around to add here, resulting in hydraulic shock. This phenomenon is called cavitation.

The so-called cavitation refers to: centrifugal pump starts, if the pump in the presence of air, because the density of air is very low, the centrifugal force generated after rotation is very small, so the impeller center area formed by low pressure is not enough to level below the pump inlet Of the liquid suction pump, can not transport the phenomenon of fluid.

Due to continuous local impact, the surface of the material will gradually fatigue damage, causing the metal surface erosion, and then the size of the cellular cavities, in addition to damage caused by metal parts, but also produce chemical corrosion phenomena, oxidation equipment. Cavitation process is unstable, the pump will produce vibration and noise, while the bubble will block the impeller channel, resulting in head, flow rate decreased efficiency. Before the start of the centrifugal pump must be filled with liquid after the pump shell, before starting, otherwise it will cause the pump heat, vibration, a liquid reduction, damage to the pump (referred to as "cavitation") caused by equipment accidents!