What kind of pump is suitable for pumping liquefied gas? The centrifugal pump we use works fine in winter, but it easily runs out of pressure in summer?
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What kind of pump is suitable for pumping liquefied gas? The centrifugal pump we use works fine in winter, but it easily runs out of pressure in summer? The pump parameters are: 0.81 cubic liters, inlet pressure of 9 kilograms, outlet pressure of 14 kilograms, and designed operating temperature of 40 degrees. The current operating conditions are as follows: the pressure in the tank at the pump inlet is 8 kilograms, and the flow rate when the outlet valve is fully open is around 2 kilograms. The pump starts to heat up after running for a while, and intermittent pumping losses occur. The pump’s impeller is of the open-type design, with a gap of 0.8–1.2 mm between the impeller and the front and rear cover plates. We suspect that the issue lies in the pump’s selection – the excessive gap between the impeller and the front cover plate causes the liquid to flow back inside the pump, resulting in heating. When the temperature rises, the liquefied gas vaporizes, leading to pumping losses. Could anyone please analyze this situation?
The parameters provided by the poster are a bit confusing. The pump parameters are: 0.81 cubic units (is the unit per minute or per hour?) Hours, right? ) 9 kilograms imported, 14 kilograms exported, designed temperature 40 degrees. The current operating conditions are that the pressure in the tank at the pump inlet is 8 kilograms, and the flow rate when the outlet valve is fully open is around 2 kilograms. (Is the pressure at full opening of the outlet valve 2 kilograms?) Why not hold the pressure at 13 kilograms? ) In any case, the person operating the pump must first ensure that it is functioning within its designed range or within the limits specified by the pump manufacturer; only then can the causes of any problems be analyzed.
A sliding vane pump is more suitable for liquefied gas.
0.81 cubic liters per hour; the flow rate will be lower when the pressure is increased to 13 kilograms
Do you have any information on vane pumps? Please share it. All I knew before was that vane pumps have better precision
Personally, I think the main issue with your question is the heating of the pump body. First, you need to analyze why this happens and under what conditions heating and vaporization occur. The reason is pressure buildup in the pump! When the suction volume of the pump is greater than its discharge volume, some liquid remains in the pump chamber; it is repeatedly subjected to the force exerted by the impeller but cannot be discharged, and thus is converted into heat. The reason for this phenomenon is the pump design, with a large inlet and a small outlet; as for operational factors, the pressure buildup results in a discharge volume that is less than the pump’s minimum flow rate. It would be easy to solve if it were a closed impeller; I’ve dealt with that before. But for open impellers, I’ve racked my brains for a long time without coming up with a good solution! Have a chance to send a picture of the impeller! Why use an open impeller? ? ? I need expert advice!
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The conditions are insufficient; if pressure buildup is to be detected, the issue must be identified in the operating current.
For the pumps used to handle liquefied gas, we choose shielded pumps; the specific reasons for this are not well understood by those who are not experts in this field
Rated current 10.7, operating current 6.7A