China slurry pump - analysis of slurry pump cavitation
China Do Pump is a manufacturer of slurry pump, sand pump. dredge pump, electric submersible sand pump and hydraulic submersible dredge pump with relative dredging equipment.Slurry Pump solutions-analysis of slurry pump cavitation, China Do Pump is a slurry pump solution provider.
Slurry pumps should be guaranteed to operate without cavitation. If the pump is operated under cavitation, the pump's overcurrent parts will be prematurely damaged under the combined action of cavitation and corrosion.
1. Conditions for pump operation without cavitation
The condition that the pump does not cause cavitation is that the effective cavitation surplus is greater than the necessary cavitation surplus of the pump. Generally, for safety reasons, a 0.3m cavitation surplus should be added, as shown in Equation 5-1,
NPSHa≥NPSHr + 0.3 5-1
Where NPSHa--effective cavitation allowance
NPSHr--required cavitation allowance
The effective cavitation margin refers to the part of the energy per unit weight of the pump inlet that is higher than the vaporization pressure energy head, and is determined by the parameters of the suction piping system and the flow rate in the piping.
The necessary cavitation margin is determined by experiment, which depends on the structure and parameters of the pump.
2. Effective cavitation allowance
There are many factors that affect the effective cavitation margin, such as the installation height of the pump, the head loss of the inlet pipeline, the local atmospheric pressure, and the temperature of the pump body. Figure 5-2 shows the relationship between the effective cavitation margin and other factors during the installation of backfill.
Note: When the slurry is composed of water and other solids, Cw≤40% Cv≤20% d50≤300um, the NPSHr of the slurry is approximately equal to the NPSHr of clean water given by the manufacturer.
Hatm --- Atmospheric pressure at the pump installation site is checked by 5-3.
When the feed box is a closed container, it should be the absolute pressure of the container page (m)
Hvap --- the slurry pump pumps the vaporization pressure of the slurry (m). When the slurry vaporization pressure is approximately equal to water, check from Figure 5-4
Hfl1 ----- The head of the clean water in the suction pipe is lost along the way. Since the suction pipe is generally short, the slurry head loss of the suction pipe can be calculated as clean water.
When the pump manufacturer gives the pump cavitation performance in the form of allowing the vacuum height (HS) to be sucked, the necessary cavitation margin of the pump can be calculated by Equation 5-3.
(M) 5-3
--- Allow suction vacuum height (m)
--- Speed at pump inlet flange (m / s)
China Do Pump is a manufacturer of slurry pump, sand pump. dredge pump, electric submersible sand pump and hydraulic submersible dredge pump with relative dredging equipment.For more sand dredge pump solutions analysis of slurry pump cavitation, contact Sand Pump Manufacturer China Do Pump at info@dopumpgroup.com or call us at +8615031104888.
