When the centrifugal pump is blocked by waste, it will be necessary to pull the pump up to sort it out, which is very inconvenient, so it is rarely used in practical activities. Therefore, the underwater pump is used to carry out low-level transportation, which solves the problem of low-level transportation.

However, due to the selection of short shaft, the unbalanced axial force of centrifugal impeller and the suspended wall structure of all shafts, great stiffness is caused at the end of centrifugal impeller during turnover. The longer the shaft, the greater the stiffness. In order to solve this problem, bearings are installed on the shaft. However, because the whole shaft is a flexible shaft, the bearing is continuously damaged on one side, with a high wear rate, strong bearing shaking and accelerated damage rate. Therefore, the damage frequency of the submerged pump is high. And the shaft is not suitable to be too long, generally within 2 meters. The bearing of the submerged pump is water-cooled and smooth with the help of the medium transported by the pump. If the medium of underwater concrete does not freeze and clean the bearing (such a thing will happen when the pump is empty and the inlet is blocked by dirt), it will burn the tile or even the motor.

The repair equipment of submerged pump is very laborious. When transporting corrosive media, it is impossible to complete without lifting items. When the centrifugal water pump is transporting liquid, when the liquid level gauge is less than, it is required to fill the pump to produce water. Therefore, the pump bottom valve shall be installed at the pump inlet. As time goes on, the bottom valve of the water pump is corroded or stuck, so it is required to exchange or repair, so the application is very inconvenient. Submersible pumps are generally used to transport cold water and rivers, but when they are used to transport corrosive liquids such as strong acid and alkali, they are prone to motor erosion and power failure, which is very unsafe. After all, the submerged pump solves the problem of low-level transportation, but it also produces a lot of difficulties in application. The column type self suction pump is specially designed for low-level liquid transportation for the defects of the submerged pump. It can replace the long axis underwater pump on the road, and the height width ratio of natural suction reaches 8m. It can be used as the bottom pump and cabin cleaning pump in the ship.
oil diffusion pump of heater and heating power