Rotor pump and screw pump both belong to positive displacement pump, and their performance is basically similar - they can stably transport high viscosity materials, have high delivery pressure. So, what are the differences between rotor pump and screw pump?
1. Internal structure is different. The rotor pump uses two rotors to rotate reversely in the pump cavity, and the volume from the feed port to the delivery port changes from large to small, so as to achieve the purpose of delivering materials. The screw pump uses a spiral screw to rotate in the rubber stator, so as to make the materials rotate from the front to the back and finally send them out from the delivery port.
2. Different life of accessories. Because there is no friction between the rotor pump parts, the service life of the wear parts of the rotor pump is very long, and the wear of the flow passage parts mainly comes from the abrasive and corrosive components in the medium; while the friction between the rotor and the stator of the screw pump, the particles in the medium and so on simultaneously affect the service life of the wear parts. All the stresses produced by the eccentric rotating rotor are borne by the stator, which aggravates the wear between the components. The stator of the pump will be gradually worn even if the medium without any particles is transported.
3. Different levels of hygiene. Because of the non streamline curved surface and many defects in the chamber of screw pump, it is impossible to be a sanitary pump. The damage of Teflon or rubber on the cavity wall is more likely to cause pollution to the conveying medium. The rotor pump has no dead point or non-metallic parts due to the streamline structure of the rotor and the rotor chamber. Therefore, the high viscosity positive displacement pump is more suitable for application in the industries with higher health requirements, such as food and beverage, medicine and so on, especially the production line automation is getting higher and higher, at the same time, more and more online cleaning is used, which shows the importance of selecting cam rotor pump 。 Therefore, the sanitary level of rotor pump is higher than that of screw pump.
4. The conveying direction is different. The delivery direction of the rotor pump can be reversed, and the pump is a completely symmetrical structure; the screw pump can not be reversed, and its seal is in the pressure state when it is in reverse delivery.
5. The self-priming ability is different. The screw pump has a good self-priming capacity, but to avoid the pump body idling, and not more than 30 seconds; the rotor pump can produce a good self-priming capacity when the speed is greater than 200 rpm.