The twin screw pump is an externally meshed screw pump, which uses two screws that mesh with each other and do not touch each other to pump liquid. The twin-screw pump is a double-suction non-hermetic twin-screw pump. The driving screw with one end extending out of the pump is driven by the prime mover. The driving screw and the driven screw have threads with different directions of rotation (if the former is right-handed, the latter is left-handed). The screw is tightly fitted with the pump body. The driven screw is driven by the driving screw through the synchronous gear. The twin-screw pump is a positive displacement pump, and the suction chamber in the pump should be tightly separated from the discharge chamber. Therefore, the outer surface of the pump body and the screw and the clearance between the screw and the screw should be as small as possible. At the same time, the screw and the pump body, and the screw and screw form a sealed cavity with each other to ensure airtightness, otherwise, the liquid may flow back from the gap.
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 working chamber of the twin-screw pump with the external bearing structure is separated from the bearing. Due to the structure of this pump and the side clearances that exist between the screws, it can transport 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, external bearing-type twin screw pumps also have self-priming capabilities, and most pump conveying elements themselves are symmetrically arranged with a double suction, which can eliminate axial forces and have a large suction height.
These characteristics of the twin-screw pump make it widely used in the oilfield chemical industry and shipbuilding industry. The external bearing type twin-screw pump can be made of different materials such as ordinary cast iron and stainless steel according to various usage conditions. Delivery temperature up to 250oC. The pump has different heating structures, and the theoretical flow can reach 2000 cubic meters per hour.
Features of twin screw pump:
No stirring, no pulsation, and smooth conveying of various media. Due to the structure of the pump body, there is always pumped liquid as a sealing liquid in the working elements of the pump. All pumps have strong self-priming ability and can be mixed with vapor and liquid. .
The special design of the pump ensures that the pump has a high suction performance that is a small NPSHr value.
The use of independently lubricated outboard bearings allows the delivery of various non-lubricating media.
Horizontal, vertical, with heating jacket and other various structural types are complete, can transport all kinds of clean low-viscosity or high-viscosity medium without solid particles, select the correct material, and even transport many corrosive media.