The operating principle of centrifugal cryogenic liquid pump is the same as that of centrifugal pump. The centrifugal pump depends on the rotating impeller to perform work on the liquid, and the mechanical energy of the original motive can be transferred to the liquid. When pump is filled with liquid inside job, because of the high speed rotating impeller, liquid in the impeller under the action of centrifugal force, driving the liquid in the process of imports to exports from the impeller flow, pressure and speed can be increased, and then in the divergent indoor and output after the speed can be further converted into pressure. Briefly generalizing: the working principle of centrifugal pump is: when the centrifugal pump works, it depends on the pressure difference between the pump and the pump, and the liquid is continuously pumped into the pump, and the liquid is obtained by the high-speed rotation of the impeller. The kinetic energy of the liquid is converted into pressure by the diffuser or the guide blade.
Reciprocating cryogenic pump is similar to the working principle of reciprocating compressor, which is a kind of volumetric compression machine. It is reciprocated by piston (plunger) in the working chamber of the liquid cylinder, so that the volume of the working chamber can be changed periodically to realize the whole process of the suction and compression.
When the piston (plunger) moves to the right, the volume of the pump cylinder increases, and the pressure decreases. When the liquid pressure in the inlet pipe is greater than the pressure in the pump cylinder, the suction valve opens and the liquid flows into the pump cylinder. When crank around 180 ° piston (piston) moves to the left, the volume of pump cylinder is reduced, because the liquid is incompressible fluid, so the pressure will rise rapidly, when the pressure rose to can open the discharge by high pressure liquid discharge valve to discharge, this is a working cycle reciprocating liquid pump.
Thus, the flow of reciprocating pump is pulsed and discontinuous. The number of pulses is determined by the speed of rotation. The discharge pressure of reciprocating pump is determined by the characteristics of the pipeline, which is because the discharge valve can be opened only when the pressure of the liquid in the pump cylinder is higher than that of the discharge pipe. Because of this, as long as the motor power adequate pump is well sealed, reciprocating pump discharge pressure, can meet the low, medium and high pressure of various pipe network pressure requirements.