Small three screw pump head

Screw pump is a rotary pump that transports liquid or pressurizes it by relying on the volume change and movement of the meshing space formed by the pump body and screw. Screw pump is divided into single screw pump, twin screw pump and three screw pump according to the number of screws. When the driving screw rotates, it drives the driven screw engaged with it to rotate together, the screw meshing space volume at one end of the suction chamber gradually increases and the pressure decreases. The volume of liquid entering the meshing space under the action of differential pressure. When the volume increases to the maximum to form a sealing cavity, the liquid moves continuously along the axial direction in one sealing cavity until one end of the discharge cavity. At this time, the volume of the screw engagement space at one end of the discharge chamber is gradually reduced to discharge the liquid. The working principle of screw pump is similar to that of gear pump, but screw replaces gear in structure. The table shows the characteristics and application scope of various screw pumps. Screw pump has small flow and pressure pulse, low noise and vibration, and has self-priming capacity, but screw processing is difficult. The pump has two structures: single suction and double suction, but the single screw pump has only single suction. The pump must be equipped with a safety valve (not necessary for single screw pump) to prevent the pump or prime mover from being damaged due to some reason, such as the outlet pressure of the pump exceeding the allowable value due to the blockage of the discharge pipe.