Principle of screw pump

- May 22, 2018-

Single screw pump is a new type of internal meshing rotary displacement pump. The main working parts are eccentric screw (rotor) and fixed bushing (stator). 2. Compared with other pumps, single screw pump has no need to install valve compared with centrifugal pump, and flow is a steady linear flow. Compared with plunger pump, single screw pump has better self-priming capability. Compared with the diaphragm pump, single screw pump can carry various kinds of mixed impurities, including gas and solid particles or fiber medium, also can transport various corrosive substances. Compared with gear pump, single screw pump can deliver high viscosity material. Unlike plunger pump, diaphragm pump and gear pump, single screw pump can be used for filling and measuring. The basic operating principle of the screw pump is to use the screw rotation to suck the liquid.

The screws on both sides are driven by the moving screw, and rotate with the active screw. The thread of the main and slave screw is double thread. Due to the meshing of each screw and the close coordination between the screw and the inner wall of the liner, it will be separated into one or more sealing space between the suction inlet and the discharge outlet of the pump. With the rotation of the screw and meshing, the sealed space in pump suction side form unceasingly, will seal in the suction chamber in the liquid, and the suction chamber along the screw axial continuously goes on to the discharge end, will be closed in the space of the liquid discharge, like a nut in screw rotation being constantly move forward, this is the basic work principle of screw pump. The sealing surface between the screw and the shell is a space surface. On this surface there are non-sealing areas such as ab or DE, and the grooves of the screw are formed in many triangular gaps ABC, def. The gap of these triangles forms the channel of the liquid, so that the active screw groove A is connected with the groove B and C on the moving screw. And the grooves B and C go around the back of their spiral, and they connect to the groove D and E on the back. Due to the sealing surface of slot D, E and slot F(which belongs to the other spiral), there is also a kind of positive triangle-shaped notch a 'b' c ', so D, F and E will also be connected. In this way, the groove ABCDEA also forms an "infinity" type of sealing space (if single thread is used, then the groove will be aligned to the disk and the screw will be cut through, unable to form a seal). It's not hard to imagine.