Different types of screw pumps can be selected according to the medium

The rotor pump and the screw pump belong to the positive displacement pump. The performance is similar – it also can smoothly transport high-viscosity substances and have high delivery pressure. So, what are the differences between rotary lobe pumps and screw pumps?

The internal structure is different. The rotor pump rotates in the opposite direction in the pump cavity through two rotors. The volume from the feeding port to the conveying port is changed from large to small to achieve the purpose of conveying materials. In contrast, the screw pump rotates in the rubber stator through a helical screw. The spiral rotation of the material from front to back is finally sent out from the discharge port.


The life of accessories is different. Since there is no friction between the rotor pump components, the worn parts have a long service life. The wear of the overcurrent components mainly comes from the abrasive and corrosive elements in the medium. In contrast, the friction between the rotor and the stator of the screw pump, The particles in the medium also affect the service life of the worn parts. The stress generated by the eccentrically rotating rotor is all absorbed by the stator, which increases the wear between the components. Even when conveying media without any particulate matter, the stator of the pump will gradually wear out.

Different hygiene levels. Due to the bluff surface of the screw pump and the many defects in the chamber, it is impossible to become a sanitary pump. Damage to the cavity wall PTFE or rubber is more likely to contaminate the conveyed medium. However, due to the streamlined structure of the rotor and the absence of dead spots and non-metallic parts in the rotor chamber, the high-viscosity positive displacement pump is more suitable for applications in industries with high hygiene requirements, such as food and beverage, medicine, etc., especially now The automation of the production line is getting higher and higher. More and more online cleaning is used, which shows the importance of choosing a rotary lobe pump. Therefore, the hygienic level of the rotor pump is higher than that of the screw pump.

Rotor pump

The conveying direction is different. The delivery direction of the rotor pump can be reversed, and the pump is a completely symmetrical structure, while the screw pump cannot be changed. The seal is under pressure during reverse delivery.

Different self-priming abilities. The screw pump has an excellent self-priming ability, but the idling of the pump body should be avoided, and it should not exceed 30 seconds; the rotor pump can produce a superior self-priming power when the speed is more significant than 200rpm.

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