Universal three-screw pump with wide application
1.The screw units is rotating along with the external prime mover.
2.The spiral groove of the screw opens periodically,and the volume of suction cavity increases,resulting into a vacuum.
3.The medium is absorbed into the spiral groove and sealed in the spiral groove.
4.Along with the rotation of screw,the medium moves toward the outlet along the axial line of the screw.
5.The medium is pumped out.This is the operating principle of screw pump.
Performance Viscosity:3.0 ~ 1500 mm2/s
Flow:5 ~ 5300 L/min
Maximum Pressure:4.0 Mpa
Maximum Temperature:150 ℃
The three-screw pump closes the conveyed medium in the meshing chamber and pushes it to the outlet continuously and uniformly along the screw axis to provide stable pressure for the system. When working, the two ends act on the suction and drainage pressure of the liquid separately, which produces the axial thrust on the screw.
In addition, the high-pressure oil is introduced into the bottom of each screw sleeve through the central oil hole of the active screw, thus generating a balanced thrust opposite to the axial thrust direction at the lower end of the screw. Therefore, thrust bearings can be used for small pumps with pressure difference less than 10 kg/cm2.
Because of the symmetrical engagement of two driven screw and active screw, the radial force acting on the active screw is completely balanced, and the active screw does not bear bending load. The radial force acting on the driven screw is supported by the pump cylinder liner along its whole length, without additional bearings at the outer end and basically without bending load.
In operation, a layer of oil film formed between the outer surface of screw and the inner wall of pump cylinder can prevent the direct contact between metals and greatly reduce the wear of screw tooth surface.
Like other volumetric pumps, when the outlet of the pump is completely closed, the pressure in the pump will rise to the danger of damaging the pump or overloading the motor. Therefore, safety valves must be installed at the suction and discharge ports of pumps. Shaft seals are usually mechanical seals and can take different forms according to the working pressure.