1. Twin screw pump structure features Twin screw pump is an external meshing screw pump, which uses mutual engagement, do not touch two screws to pump liquid. Twin screw pump as a positive displacement pump, pump suction chamber should be closely spaced with the discharge chamber. Therefore, the pump body and the outer surface of the screw and screw and screw clearance should be as small as possible. At the same time, the screw and the pump body, the screw and the screw also form a sealed chamber with each other to ensure airtightness, otherwise liquid may flow backwards from the gap. Twin Screw Pump Twin Screw Pump can be divided into built-in bearings and external bearings in two forms. In the built-in bearing structure of the bearing lubrication by the transport. The external bearing structure of the twin-screw pump cavity with the bearing is separate. Due to the structure of this pump and the side clearance existing between the screws, it can deliver non-lubricative media. In addition, adjusting the synchronizing gear makes the screw non-contact while transmitting half of the output torque to the driven screw. As with all screw pumps, the external bearing twin screw pump also has a self-priming capability and most pump delivery elements themselves are double-suction symmetrically arranged to eliminate axial forces and also have a large suction height. These characteristics of the pump make it in the oil field chemical and shipbuilding industry has been widely used. External bearing-type twin-screw pump can be used according to various conditions, ordinary cast iron, stainless steel and other different materials. Delivery temperature up to 250ºC. The pump has a different heating structure, the theoretical flow rate up to 2000 cubic meters / hour. The characteristics of twin-screw pump: no stirring, no pulsation, smooth delivery of a variety of media, as the pump structure to ensure that there is always pump working fluid pumping liquid as a sealing liquid, all pumps have a strong self-absorption capacity, And can be liquid-vapor mixed. The special design of the pump ensures that the pump has a high suction performance, ie a very small NPSHr value. The use of independent lubrication of the external bearings, allowing delivery of a variety of non-lubricating media. Horizontal, vertical, with heating jacket, and other structures complete, can transport a variety of clean solid particles without low viscosity or high viscosity medium, the choice of the right material, and even can transport many corrosive media. 2. The use of twin-screw pump known by the principle of twin-screw pump, twin-screw pump for external bearings, positioning by the bearing, the two screws in the bushing do not touch each other, to maintain a constant gap between the flanks (the gap The value is determined by the working conditions and the pump itself), the constant clearance between the screw outer circle and the bushing inner surface remains unchanged. Two screw drive by the synchronous gear to complete. There is a separate lubrication in the gearbox, separated from the pump working chamber. The advantages of this structure greatly broaden the use of dual-screw pump, that is: In addition to conveying a good lubrication medium, but also transport a large number of non-lubricative media, a variety of viscosity (the highest viscosity up to 3 * 106mm / s) Of the medium and corrosive (acid, alkali and other properties), abrasive liquid. Due to their constant clearance and profile features, twin-screw pumps are non-hermetic positive displacement pumps and therefore deliver a mixture of gas and liquid, that is, a mixture of gas and liquid, in addition to the pure liquid, which is also twin screw One of the advantages of pumps is very unique. Twin screw pump structure Twin screw pump due to the unique structure of the design, can be self-priming without the need for special self-priming device, but also due to the axial transport axial flow rate is small and has a strong suction capacity that is small NPSHr value. Twin screw pump can also dry rotation. Because the moving parts do not touch each other during work, short-term dry rotation will not damage the pump components. This feature greatly facilitates the automatic control flow, but the dry running time is limited by many factors and is generally short . In addition the twin-screw pump in the transport process without shear, no emulsification, it will not undermine the molecular chain structure and working conditions in the process of the formation of a specific fluid properties, and because the transmission relies on synchronous gear, pump low noise, low vibration Work steadily.
