Screw pumps are positive displacement rotor pumps, which rely on the volume change of the sealed cavity formed by the screw and bushing to suck and discharge liquid. Screw pumps are divided into single screw pumps, double, triple and five screw pumps according to the number of screws. The characteristics of screw pump are stable flow, small pressure pulsation, self-priming ability, low noise, high efficiency, long life, and reliable work. Its outstanding advantages are that no eddy current is formed when the medium is transported, and the viscosity of the medium is not sensitive. Handling high viscosity media.


Basic working principle
    1. Screw pump uses the rotation of the screw to suck and discharge liquid.
    Due to the mutual engagement of the screws and the close cooperation of the screws with the inner wall of the liner, between the suction inlet and the outlet of the pump, it will be divided into one or more sealed spaces. With the rotation and meshing of the screw, these sealed spaces are continuously formed on the suction side of the pump. The liquid in the suction chamber is enclosed therein, and it is continuously moved from the suction chamber along the screw axis to the discharge end. The liquid is continuously discharged, as if a nut is continuously pushed forward when the thread is turning. This is the basic working principle of the screw pump.
    2. The working principle of the screw pump is: When the screw pump is in operation, the liquid is sucked into the sealed space surrounded by the screw and the pump casing. When the active screw rotates, the screw pump's sealing volume is increased by the screw squeeze. Pressure and move in the axial direction. Because the screw rotates at a constant speed, the liquid outflow is also uniform.
    The characteristics of screw pump are: small loss of screw pump and good economic performance. The pressure is high and uniform, the flow is uniform, and the speed is high, which can be directly connected to the prime mover.
    Screw pumps can transport lubricating oil, fuel oil, various oils and polymers, and are used to transport viscous liquids.
    Conveying high-viscosity media: Depending on the size of the pump, it can convey media with a viscosity from centipoise.
    Media containing particles or fibers: the diameter of the particles can be 30mm (not exceeding the eccentricity of the rotor). The fiber length can be 350mm (equivalent to the pitch of a 0.4-position rotor). Its content can generally reach 40% of the media cellar. If the solid matter in the medium is a fine powder, the maximum content can reach 60% or higher.
    When the conveying pressure is required to be stable and the inherent structure of the medium is not damaged, a single screw pump is the most ideal.