Cavitation phenomenon of pump: cavitation corrosion occurs on the metal surface in contact with fluid under the condition of high speed flow and pressure change.Often occurs in such as centrifugal pump blade tip high speed pressure reduction area, where the formation of holes, holes in the high pressure area is broken and impact pressure, damage the protective film on the metal surface, and accelerate the corrosion speed.Cavitation is characterized by the formation of many small pitting points on the metal surface and then gradually expanding into caves.
When the pump is in operation, a part of the impeller inlet blade head is at a lower position of the pressure of the liquid flow. When the local pressure of the liquid at this part is reduced to equal to or lower than the pressure of vaporization at the time temperature, the liquid flow will always be vaporized and bubbles will be born there.From inside the bubble is full of steam and liquid precipitation and scattered into the air bubbles some active gases (oxygen), when these bubbles with liquid in the pump pressure to high pressure parts, high pressure fluid flow around the bubble under the influence, bubbles were shrinkage and deformation and breaking, born great belongs to the introverted explosive qualitative condensation.
What problems will occur when cavitation occurs:
1.Slurry pump cavitation caused by insufficient pump output
Pump output is insufficient refers to the head and flow are to achieve the pump should achieve the index, there will be the following phenomenon:
When designing the conveying system, cavitation characteristics are not fully considered. If the critical cavitation flow rate is less than the required flow rate, cavitation will occur at the critical cavitation flow rate when the slurry pump is in operation, resulting in a large drop in the head of the slurry pump and insufficient output.
Solution: it is to change the pipeline device system, or replace the pump with better cavitation performance, so that the pipeline device cavitation residual at the required flow rate is greater than the 2.Pump required cavitation residual.
Suction pipe blockage causes cavitation of slurry pump
Slurry pump suction pipe blockage is easy to cause cavitation pump, will also make the pump output is insufficient.
Reason: large particles or long fiber material blocked pipeline inlet, impeller inlet, filter inlet and pump inlet valve damage can not be fully opened.
Solution: remove blockage and repair pump inlet valve.
3.Cavitation operation
Slurry pump running in cavitation state, will make the pump vibration and noise, but also make the life of the pump significantly reduced, slurry pump cavitation is serious when the pump can not work.