When a centrifugal water pump is blocked by waste, it is necessary to pull the pump up in order to sort it, which is very inconvenient and therefore rarely used in practical activities. Therefore, using a submerged pump to carry out low-level transportation solves the problem of low-level transportation.
However, due to the use of a short shaft and the uneven axial force of the centrifugal impeller, all shafts are of a suspended wall structure, resulting in significant stiffness at the end of the centrifugal impeller during flipping. The longer the axis, the greater the stiffness. In order to solve this problem, the equipment on the shaft has bearings. However, because the whole shaft is a Flexible shaft, the bearing continues to suffer from unilateral damage, with a high wear rate, strong bearing shaking, and accelerated damage rate. Therefore, the underwater pump has a high frequency of damage. And the shaft is not suitable for making too long, usually within 2 meters. The bearings of the submerged pump are cooled and polished by water using the medium transported by the pump. If the medium of underwater concrete does not freeze and clean the bearings (such incidents can occur when the pump is empty and the inlet is blocked by dirt), it will cause burning of the tiles or even the motor.
The repair equipment of the submerged pump is very laborious. When transporting corrosive media, it is impossible to complete without lifting items. When a centrifugal water pump is transporting liquid, when the liquid level gauge is less than, it is required to fill the pump in order to produce water. Therefore, it is necessary to install a water pump bottom valve at the pump inlet. Over time, if the bottom valve of the water pump is corroded or stuck, exchange or repair is required, making the application inconvenient. Submersible pumps are generally used to transport cold water and rivers, but when used to transport corrosive liquids such as strong acids and alkalis, they are prone to motor erosion and power loss, making them very unsafe. After all, the submerged pump solves the problem of low level transportation, but it also incurs many difficulties in applications. The column type self priming pump is designed specifically for the transportation of low level liquids due to the aforementioned defects of the submerged pump. It can replace a long axis underwater pump on the road, with a naturally aspirated aspect ratio of up to 8 meters. It can be used as a bottom pump and a cabin cleaning pump in ships.