What is cavitation, centrifugal pump cavitation phenomenon how to solve?
Centrifugal pump cavitation phenomenon how to solve?:Measures to improve cavitation resistance of centrifugal pumps(1) improve the design of the suction port of the centrifugal pump to the impeller. Increase flow area; the radius of curvature increases the impeller cover inlet section, reduce the flow accelerated sharply with pressure; reduce the thickness of the blade, and the blade inlet rounded, close to the streamline, can also reduce the acceleration and pressure flow around the blade head portion of the impeller and the blade inlet part; improve surface finish in order to reduce the resistance loss; the blade inlet edge extends to the impeller inlet, the liquid flow in advance to accept work pressure, improve.
The pump is in operation, if the over-current part of the local area (usually the impeller blade inlet somewhere later) for some reason, the absolute pressure of pumping the liquid was reduced to liquid vapor pressure temperature, liquid vaporization began in the area, produce a lot of steam, forming bubbles, when the liquid contains a lot of bubbles forward by high pressure impeller zone, high pressure liquid around the bubbles in the bubble decreases drastically and rupture. Condensation in the bubble burst at the same time, the liquid particle filled hole at a high speed, this moment has a very strong effect of water hammer, and with a high impact frequency against the metal surface, the impact stress of hundreds to thousands of atmospheric pressure, impact frequency can be up to tens of thousands of times per second, serious breakdown when the wall thickness will be.The process of cavitation in a pump is caused by the bursting of bubbles and bubbles in the water pump and the destruction of the over-current components. Water pump cavitation, in addition to the over-current components will have a destructive effect, but also noise and vibration, and lead to the performance of the pump down, seriously when the pump will be interrupted liquid, can not work properly.
In order to make the pump full of liquid, usually in the valve installed at the bottom of the filter screen along the suction pipe, the valve until the end against the valve, strainer prevents the solid material into the normal operation of the pump impeller damage or hinder the pump.
First, what is cavitation?:When the centrifugal pump shell has air, it produces less centrifugal force because the density of the air is much smaller than the density of the liquid. Thus, suction pressure at the entrance to the top of the tank liquid level and pump is bad enough to the liquid storage tank into the pump, the centrifugal pump self suction capability, the centrifugal pump can not transport liquid, this phenomenon is called "cavitation".When a liquid drops at a certain temperature to the vapor pressure at that temperature, the liquid produces a bubble. The phenomenon of producing bubbles is called cavitation. When the cavitation bubbles, flow to the high pressure, the volume of reduced, so as to burst. This due to the pressure of rising bubbles disappear in the liquid in the phenomenon called cavitation bubble collapse.
