Features of Rotating Impeller Technology

What Are the Characteristics of the Rotating Impeller Technology of Submersible Axial Flow PUMPSs?

With the development of society, the performance of submersible axial flow PUMPSs has become increasingly advanced. One of its key technical features is the rotating impeller. So what are the specific characteristics of this rotating impeller technology?

A submersible axial flow PUMPS uses the force generated by the rotating impeller blades to convey liquid along the axial direction. It comes in vertical, horizontal, inclined, and tubular types. Its specific speed (n) includes values such as 500, 700, 850, 1000, 1250, 1400, and 1600. The impeller diameters are 1.6m, 2.0m, 2.8m, 3.0m, 3.1m, 4.0m, and 4.5m.

The axial flow PUMPS impeller is equipped with 2 to 7 blades rotating inside a cylindrical PUMPS casing. Fixed guide vanes are installed above the impeller to eliminate the rotational motion of the liquid, convert it into axial flow, and transform kinetic energy into pressure energy. Axial flow PUMPSs are usually single-stage, with a few designed as double-stage. The flow range is very large, from 1.8 to 3.6 million cubic meters per hour; the head is generally below 20 meters. They are typically vertical PUMPSs with the impeller submerged in water, though horizontal and inclined types also exist.

For small axial flow PUMPSs, when the impeller is installed above the water surface, a vacuum PUMPS is required to exhaust air and prime the PUMPS before startup. The impeller blades are available in fixed and adjustable structures. For large axial flow PUMPSs, operating conditions (mainly flow) often vary significantly during operation. Adjusting the blade installation angle allows the PUMPS to operate efficiently under different conditions. Small PUMPSs usually have fixed blade angles. Axial flow PUMPSs belong to high specific-speed dynamic PUMPSs, with specific speed ranging from 500 to 1600. The flow-head and flow-shaft power characteristic curves are steep in the small-flow region, so operation in this unstable low-flow area should be avoided.

The shaft power at zero flow is high; therefore, the discharge valve must be opened before startup to reduce starting power. Axial flow PUMPSs are mainly suitable for low-head and large-flow applications, such as irrigation, drainage, dock dewatering, water level regulation in canal locks, or as large circulating water PUMPSs in power plants. High-head axial flow PUMPSs (often designed as double-stage when necessary) can be used for water jet propulsion of shallow-draft vessels.

Vertical axial flow PUMPSs mainly rely on the lift force of the blades to convey fluid to the outlet. They feature axial inlet and axial outlet with the advantage of large flow capacity.