A Brief Introduction to Three-Screw Pump
A three-screw pump is a positive displacement fixed-flow pump with certain self-priming capacity. It features a compact structure. Inside the precisely fitted pump body are one driving screw and two symmetrically arranged driven screws. The screws mesh with one another to deliver fluid axially in a stable and efficient manner.
Before the first startup, the pump body must be fully filled with fluid. This forms a complete oil film between the precisely meshed screw pairs, spiral grooves and bushings, providing effective oil film support and protection for the screws, spiral grooves and bushing inner bores during startup. It prevents metal-to-metal contact between the screws and the bushings. During operation, atmospheric pressure difference forces fluid into the pump cavity. Driven by the rotating screws, the pump core assembly does not compress the fluid. The fluid flows steadily along the axial direction of the screws toward the pump outlet and is then delivered to supporting equipment.
Three-screw pumps have a wide range of applications. They are suitable for conveying clean, non-corrosive fluids with lubricity and appropriate viscosity and free of abrasive particles, including lubricating oil, mineral oil, fuel oil, hydraulic oil, coolant, turbine oil, seal oil, aromatic oil, crude oil and asphalt. Accordingly, three-screw pumps are widely used in power plants, iron and steel metallurgy, marine shipping, machine tool processing, oil and gas, petrochemical refining and other industrial fields.
Main Advantages of Three-Screw Pumps
- Low Pulsation: It delivers fluid stably and continuously without acceleration or extrusion of the conveyed medium.
- Self-Priming Capacity: It is applicable to working scenarios such as low liquid levels and underground oil tanks.
- Quiet and Low-Noise Operation: The continuous and stable fluid delivery with low pulsation enables the pump to operate with low noise.
- Long Service Life: Adopting the hydrodynamic support working principle, the pump minimizes operational wear between screws and bushings, featuring a long service life and low maintenance workload.
- High Efficiency: The three-screw pump converts most driving power into effective hydraulic energy. Stable delivery, precise tolerances between screws and the pump body, and low axial acceleration of fluid greatly reduce internal backflow, achieving optimal operating efficiency.
