3G three screw pump

3G three screw pump is used to transport media with temperature ≤ 150 ℃, viscosity 3-760cst, no solid particles, no corrosion and lubricating performance. 3G three screw pump is mainly used in fuel oil transportation, hydraulic engineering machinery industry and heavy machinery industry, shipbuilding and offshore engineering, oil tank and printing and dyeing industry, chemical industry, petrochemical and other industries.

3G three screw pump generally adopts mechanical seal (special requirements, magnetic drive and zero leakage structure can be selected). The pump is driven by a motor through a claw coupling. Viewed from the extended end of the main shaft to the pump, it rotates clockwise.

3G three screw pump includes 3gr three screw pump, 3gc marine type and special type. This type of 3G screw pump is a rotor positive displacement pump. Due to the mutual meshing of the spiral grooves on the driving screw and the driven screw and their cooperation with the inner surface of the three holes of the bushing, several stages of dynamic sealing chambers can be formed between the inlets of 3G screw pump, These dynamic sealing chambers will continuously move the liquid axially from the inlet of 3G screw pump to the pump outlet, and boost the transmitted liquid step by step, so as to form a continuous, stable and axially moving pressure liquid in 3G screw pump.

Features of 3G three screw pump:

1. 3G screw pump has high suction capacity.

2. Long service life: the driving screw of 3G screw pump is driven by motor. There is no mechanical contact between the master and slave rods, but driven by the transmitted pressure liquid, the slave rotates around the axis. There is a layer of oil film protection between the master and slave rods and between the screw and the bushing. Therefore, the mechanical friction of 3G screw pump is very small, and the service life can be called semi permanent.

3. The transmitted liquid moves axially at a uniform speed in a straight line in the 3G screw pump, so the pressure pulsation is small, the flow is stable and the noise is low. Due to the small inertia of the rotating part of the 3G screw pump, the starting torque and vibration are very small.

4. Simple structure: 3G screw pump has a variety of structural forms, generally with a small flow of 0.2-6.5m/h. The pump body and bushing of 3G screw pump are combined into one (collectively referred to as the pump body) and the shaft seal is the end face mechanical seal. The pump bushing of 3G screw pump with medium flow above is a separate part fixed in the pump body. The large flow 3G screw pump is mostly made into double suction structure and installed horizontally. The shaft seal has two kinds of end face mechanical seal and packing seal according to the different transmission medium. The installation forms of marine 3G screw pump are horizontal and vertical, and the prime mover is AC and DC marine motor.

5. In order to ensure the safety of 3G screw pump, motor and pipeline system, screw pumps with medium flow above are equipped with safety valves when the pressure exceeds the set pressure of the safety valve. High pressure oil will return to the oil inlet of 3G screw pump.

As a conventional artificial lift mining method, mechanical oil production plays an important role in oil field production all over the world because of its mature technology, easy to master, reliable performance and strong adaptability. Especially in the middle and late stage of oilfield development, mechanical oil recovery has become the main artificial lift production mode in the oilfield. At present, pumping units and electric submersible pumps are mainly used as the main lifting equipment for mechanical oil production in the world, and screw pump oil production is a new mechanical production mode developed in recent ten years, which has gradually expanded application fields and broad application prospects, and is expected to replace artificial lifting methods such as pumping units and electric submersible pumps.

Screw pump is a rotary positive displacement pump, which has the advantages of both positive displacement pump and centrifugal pump. Screw pump has few moving parts, no valves and complex flow channels, good suction performance, small hydraulic loss, continuous and uniform suction and discharge of lifting medium, so that solid particles are not easy to deposit, pump jamming and air lock are not easy to occur.

At present, there are two kinds of screw pump oil production systems applied at home and abroad. One is the ground driven single screw pump oil production system, and the other is the submersible motor driven single screw pump oil production system.

The surface driven screw pump production system is a mechanical production equipment in which the ground power drives the sucker rod string to rotate and makes the screw pump rotor rotate at low speed to realize lifting. The submersible motor drives the screw pump oil production system, which is a mechanical oil production equipment in which the downhole submersible motor directly drives the screw pump rotor to rotate at high speed to lift.

As a new artificial lifting method, screw pump oil production has attracted much attention from oil fields at home and abroad because of its incomparable advantages, such as low investment, simple equipment structure, convenient operation, obvious energy-saving effect and strong adaptability, which can effectively reduce oil production cost and improve oil production efficiency, such as pumping unit plunger pump, submersible electric pump and hydraulic piston pump, It is expected to become one of the main mechanical production methods in the oilfield.

Performance parameters of 3G three screw pump: