Submersible axial flow pump type, working principle and features

Submersible axial flow pump is a kind of vane pump. It is not the same as the centrifugal pump liquid flow along the radial, but along the pump axis direction of flow, so called axial pump. And because its blades are spiral, much like the aircraft and ships on the propeller, so some, also known as the propeller pump.
    1, the type of axial flow pump
    Axial flow pump according to the installation location can be divided into vertical shaft, inclined and horizontal three. Between them only the pump body form is different.The internal structure is basically same. China's production is more vertical axial flow pump.
    Vertical axial flow pump internal structure, which is mainly by the pump, impeller, different leaf devices and the composition of the import and export of tubes. The shape of the pump body is cylindrical, the impeller is fixed on the pump shaft, the pump shaft has two bearing supports in the pump body, and the pump shaft is connected with the motor shaft through the top coupling.
    Impeller is generally composed of curved blades, the shape and the fan blades are similar, there is distortion. The structure of the blade has two fixed and spiral angle can be adjusted. Adjustable blade and semi-adjustable and fully adjustable two. Semi-adjustable blade is removable, change the angle of the blade to be released by manual adjustment; full regulation is through a special set of automatic follow-up mechanism to change the angle of the blade. Large-scale axial flow pump blades are mostly full "Regulating" powered by.

    Guide vane device shape is conical or cylindrical, generally equipped with a guide vane. The guide vanes function to increase the efficiency of the pump by increasing the pressure from the liquid flowing out of the impeller through the flow path formed by the guide vanes.
    The inlet pipe is flared and the outlet pipe is typically a 60 ° or 90 ° elbow, which serves to change the flow of liquid
Out of the direction.

    2, the working principle of axial flow pump
    Axial flow pump does not rely on the centrifugal force of the impeller on the liquid, but the use of rotating impeller blades to be transported by the thrust of the liquid along the pump axis direction of flow. When the pump shaft driven by the motor rotation, due to the blade and pump shaft axis has a certain helix angle, so the liquid produce thrust (or called lift), the liquid pushed out along the discharge pipe. This is similar to the reason the fans run, close to the front of the fan blades are pushed to the front of the air, the air flow. When the liquid is pushed out, the original position will form a partial vacuum, the outside of the liquid under the action of atmospheric pressure will be sucked into the impeller along the inlet tube. As long as the impeller continuously rotating, the pump will be able to continue to inhale and discharge liquid.
    3, the characteristics of axial flow pump
          (1) the advantages of axial flow pump
        1) flow, simple structure, light weight, small size, its shape is tubular, so the area.
        2) Vertical axial flow pump impeller all immersed in the water, starting without priming pump, easy to operate.
        3) For the axial flow pump, when the working conditions change, as long as the change of blade angle, can still maintain
Working at higher efficiency.
          (2) the main drawback of axial flow pump head is too low, so the scope of application is limited.
 
   As the submersible axial flow axial flow pump is a low head and large flow pump, it is usually used for agricultural large area irrigation and drainage, urban drainage, transportation needs a large amount of cooling water thermal power station circulating water, and the dock lift water level.