The working principle and advantages and disadvantages of the filter lift pump!

With the development of the chemical industry and the improvement of people's awareness of the environment and safety, the requirements for chemical pumps are getting higher and higher. In some cases, some pumps are required to have no leakage. This demand promotes the development of filter lift pump technology. Since there is no shaft seal, the filter lift pump can achieve the effect of no leakage, so the use of chemical plants has become more and more common.
1. The working principle and structural characteristics of the filter lift pump

The drive of an ordinary centrifugal pump is to connect the impeller shaft of the pump with the electric shaft through a coupling, so that the impeller and the electric motor rotate together to work. The filter lift pump is a sealless pump. The pump and the drive motor are sealed in a pressure vessel filled with pumping medium. The pressure vessel has only a static seal, and a wire group provides a rotating magnetic field and drives the rotor. This structure cancels the rotating shaft sealing device of the traditional centrifugal pump, so that no leakage can be achieved.

The filter lift pump connects the pump and the motor together. The rotor of the motor and the impeller of the pump are fixed on the same shaft. The rotor of the motor is separated from the stator by a shielding sleeve. The rotor runs in the medium to be transported, and its power passes through the stator. The magnetic field is transmitted to the rotor.

In addition, the manufacture of the filter lift pump is not complicated, and its hydraulic end can be designed and manufactured according to the structural type and relevant standard specifications commonly used in centrifugal pumps.

2. The advantages and disadvantages of filter lift pump

Advantages of 2.1 filtration lift pump

(1) Completely closed. There is no dynamic seal on the structure, only in the pump shell has a static seal, so it can be done without leakage, especially suitable for conveying flammable, explosive, valuable liquids and toxic, corrosive and radioactive liquids.

(2) High security. The rotor and stator each have a shielding sleeve so that the motor rotor and stator do not contact with the material, even if the shielding sleeve is broken, there will be no danger of external leakage.

(3) The structure is compact and the area is small. The pump and the motor are integrated, and there is no need to locate the center for disassembly and assembly. The requirements for the base and foundation are low, and the daily maintenance workload is small, and the maintenance cost is low.

(4) smooth operation, low noise, no need to add lubricating oil. Because there is no rolling bearing and motor fan, it does not need to add lubricating oil, and the noise is low.

(5) a wide range of use. High temperature, high pressure, low temperature, high melting point and other conditions can meet the requirements.

Disadvantages of 2.2 filter lift pump

(1) Since the filter lift pump uses sliding bearings and is lubricated with the medium to be transported, the medium with poor lubricity should not be transported by the filter lift pump. Generally suitable for filtration lift pump media viscosity of 0.1-20mPa.s.

(2) The efficiency of the filter lift pump is usually lower than that of the single-end mechanical seal centrifugal pump, and is roughly equivalent to the double-end mechanical seal centrifugal pump.

(3) for a long time in the case of small flow operation, filter lift pump efficiency is low, will lead to heat, so that the liquid evaporation, and cause the pump dry, thereby damaging the sliding bearing.