Help! What kind of pump can feed material under negative pressure at the inlet? Can a reciprocating pump be used?
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Since it is a negative-pressure system at around -90 kPa, the material in the system enters two receivers from which it is then discharged in turn; this makes automation difficult. We tried using a centrifugal pump with direct inlet under negative pressure to feed the material, but this caused the pump to run idle. Could anyone tell me if a reciprocating pump would work?
It is recommended to include a schematic diagram showing the properties of the materials and the pressure at each point, to facilitate discussion and as a reference.
This post was last edited by bfdlwolf on 2021-8-16 08:37. Rotary piston pump: The rotor consists of a pair of conjugate cams; as the cams rotate, the suction port becomes vacuum, and the liquid fills the entire pump chamber. The cam continues to rotate, sending the enclosed liquid to the outlet; there are no suction valve or discharge valve. It is called a rotary piston pump in China, while abroad it is known as a cam rotor pump or rotary cam pump
A centrifugal pump can be used; reference can be made to the heat well pump used for transporting condensate from the heat well of a condensing steam turbine.
Diaphragm pump: Before starting the pump, it is necessary to break the vacuum and fill the pump
For similar operating conditions here, the vacuum level needs to reach -98 kPa. Initially, centrifugal pumps were used for this purpose, but they kept running out of liquid; switching to pneumatic diaphragm pumps resolved the issue. However, since the flow rate required here is low, it’s safer to use diaphragm pumps with a higher flow rate – they provide greater suction power and are also cheaper. For applications with high flow rates and long-term use, it is recommended to use motor-driven systems; it’s also best to opt for imported ones