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Application of submersible sewage pump
- Mar 05, 2018 -

The application of the one, auxiliary impeller fluid dynamic seal technology

The so-called hydrodynamic impeller seal Deputy refers to the installation of an open impeller in the opposite direction near the back of the coaxial pump impeller hub. When the pump works, the auxiliary impeller rotates along with the main shaft of the pump. The liquid in the auxiliary impeller will rotate together. The rotating liquid will generate an outward centrifugal force. On the one hand, the centrifugal force will stop the liquid flowing to the mechanical seal and reduce the pressure at the mechanical seal. On the other hand, the solid particles in the medium are prevented from entering the friction pair in the mechanical seal, reducing the wear of the mechanical seal grinding block and prolonging its service life.

Vice impeller play a role in addition to sealing, but also can reduce the axial force in the submersible sewage pump is mainly in the axial force acting on the impeller on the liquid pressure force and the rotating part of the gravity of the composition, the direction of the two force is the same, efforts are made by the two forces add a. It can be seen that in the case of the same performance parameters, the axial force of the submersible pump is larger than that of the ordinary horizontal pump, and the balance is harder than the vertical pump. So in the submersible pump, the reason that the bearing is easy to damage is also closely related to the axial force.

If the auxiliary impeller is installed, the direction of the pressure difference acting on the auxiliary impeller is opposite to the above two forces, which can cancel part of the axial force and prolong the bearing life. But the use of the auxiliary impeller seal system also has one drawback. That is to consume a part of the energy on the auxiliary impeller, which is usually around 3%. However, as long as the design is reasonable, the partial loss can be reduced to a minimum.

Two, the application of the non overload design technology of the pump

In general centrifugal pump, the power is always increased with increasing flow, that is to say, the power curve is an increase with the rising flow curve, the use of the pump will bring about a problem: when the pump is in operation at the operating point for design, in general, less than the motor rated power power pump the use of this pump is safe; but when the pump head decreases, the flow will increase (from the pump performance curve can be seen), power is also increased.