In terms of structure, the twin-screw pump is also very complete, with various types such as horizontal, vertical, heating jacket, etc., which can transport low-viscosity or high-viscosity media with particles, adjust the screw spacing according to the particle size, and select the correct material. Even much corrosive media can be transported.
Twin-screw pumps can be divided into two forms: built-in bearings and external bearings.
In the design of the built-in bearing, the bearing is lubricated by the conveying material. The twin-screw pump with the external bearing structure has the working chamber separated from the bearing. There is a side clearance between the structure of this pump and the screw, and the independently lubricated outboard bearings allow it to transport a variety of non-lubricating media. In addition, the synchro gear is adjusted so that the screws do not touch, and at the same time, half of the output torque is transmitted to the driven screw. Like all screw pumps, the external bearing type twin screw pump also has the self-priming ability, and most pump conveying elements themselves are symmetrically arranged with a double suction, which can eliminate axial force and also have a large suction height.
The advantages of the twin-screw pump structure with external bearings greatly broaden the scope of use of the twin-screw pump, that is, in addition to transporting good lubricating media, it can also transport a large amount of non-lubricating media with various viscosities (the highest viscosity can reach 3. *106mm/s) medium and corrosive (acid, alkali and other properties), abrasive liquid;
In addition, the twin-screw pump is a non-sealed positive displacement pump due to the existence of its constant gap and the characteristics of the molding line. Therefore, in addition to transporting pure liquid, it can also transport a mixture of gas and liquid, that is, gas-liquid mixed transport, which is also a double-screw pump. One of the very unique advantages of the screw pump;
The twin-screw pump can also run dry: because the moving parts do not contact each other during operation, the short-term dry running will not damage the pump components. This feature provides great convenience for the automatic control process, but the dry running time is limited. A variety of factors limit, generally very short. In addition, the twin-screw pump has no shearing and emulsification during the conveying process, so it will not destroy the molecular chain structure and the specific fluid properties formed in the working condition process, and because the transmission relies on synchronous gears, the pump operates with low noise and vibration. , work smoothly.
What are the advantages of a twin screw pump?
1) The conveying liquid is stable, with no pulsation, no stirring, small vibration, and low noise.
2) It has a strong self-priming performance. When multiphase is mixed, the gas content is not higher than 80%, and the sand content is not higher than 500g/m3.
3) The external bearing structure adopts independent lubrication, which can transport various non-lubricating media.
4) Driven by synchronous gears, there is no contact between the two rotors, even if it is idling for a short time.
5) The pump body is equipped with a heating jacket, which can transport various clean or low-viscosity or high-viscosity media containing small solid particles (generally, the particle diameter is less than 0.12-0.2mm)
6) With the correct selection of materials, it can even transport many corrosive media.
7) Double suction structure, there is no axial force on the rotor.
8) The shaft end adopts a mechanical seal or bellows mechanical seal, which has the characteristics of long service life, less leakage, and wide application range.
