What are the types of screw pumps and what are the differences between them

Screw pumps are divided into single screw pumps, twin screw pumps, and three screw pumps. This article elaborates on the differences between the four aspects of their structure, characteristics, performance parameters, and applications, as well as their respective advantages and disadvantages. For example, the structure of the single screw pump is that the single-head male screw rotor rotates eccentrically in the special double-head female screw stator (the stator is soft), which can swing back and forth along the center line of the pump, and always keeps meshing with the stator. The structure of the twin screw pump In order to have two screw shafts of the same size, one is the driving shaft and the other is the driven shaft, which is driven by gears to achieve synchronous rotation, and so on. Single screw pump structure: Single-head male screw rotor eccentrically rotates in a special double-head female screw stator (the stator is soft), can swing back and forth along the center line of the pump, and always keep meshing with the stator. Features:
1. It can transport liquids containing solid particles. 2. It can be used for almost any viscosity fluid, especially suitable for high viscosity and non-Newtonian fluids. 3. The working temperature is limited by the stator material. Performance parameters: flow rate up to 150m³/h, pressure up to 20MPa Application: Used in molasses, pulp, starch paste, chocolate paste, paint, tar, paraffin, grease, mud, clay, pottery clay, etc.
Twin screw pump: Structure: There are two screw shafts of the same size, one is the driving shaft and the other is the driven shaft. The synchronous rotation is achieved through gear transmission. Features: 1. The screw and the pump body, as well as the screw, maintain 0.05~ 0.15mm gap, small wear, long life 2. Stuffing box is only affected by suction pressure and less leakage 3. Compared with three-screw pump, it is not sensitive to impurities. Performance parameters:
The pressure is generally about 1.4MPa, for viscous liquids, the maximum is 7 MPa, and the viscosity is up to 3 MPa. The flow rate is generally 6~600m³/h, and the maximum liquid viscosity of 1600 m³/h should not be greater than 1500mm²/s. Application: Use Used in lubricating oil, grease, crude oil, asphalt, fuel oil and other high-viscosity oils
Three-screw pump structure: It is composed of a driving screw and two driven screws that mesh with it. Features: 1. The driving screw directly drives the driven screw without gear transmission. The structure is simple. 2. The pump body itself is used as a screw. Bearings, no need to install radial bearings 3, the screw does not bear bending load, can be made very long, so high pressure can be obtained 4, not suitable for transporting liquids containing solid impurities above 600μm 5, can run at high speed, is a small and large Flow pump, high volumetric efficiency 6. The stuffing box is only connected to the suction pressure, and the leakage is small. Performance parameters: the pressure can reach 70 MPa, and the flow rate can reach 2000m³/h. Suitable for medium applications with a viscosity of 5~250 mm²/s: suitable for transporting lubricating oil, heavy oil, light oil and crude oil. It can also be used for the delivery of high-viscosity liquids such as glycerin and viscose.