Feb 17, 2020
The key parts of the submerged pump are as follows. Now, the details are as follows:
(1) Impeller is the core part of submerged pump.
According to its mechanical structure, it can be divided into three types: closed type, semi closed type and open type. Closed impeller is suitable for cleaning liquid of conveyor; semi closed impeller and open impeller are suitable for mixing liquid with solid particles of conveyor, and the high efficiency of this pump is low.
According to different suction methods, impeller can be divided into single suction and double suction. The single suction impeller is simple in structure, and the liquid can only be sucked in from one side. The double suction impeller can absorb the liquid symmetrically from both sides of the impeller. It not only has a great capacity of suction, but also mostly removes the radial thrust.
According to the geometry shape of the blade on the impeller, the blade can be divided into three types: backward bending, axial bending and forward bending. Because the mechanical energy of the backward curved blade is beneficial to the transformation of the liquid into the negative pressure energy, it is widely used; the axial blade is used in a part of the flow pump and the non blocking pump; the forward curved blade is rarely used in the submerged pump.
(2) The guide vane and pump casing can reduce the kinetic energy damage caused by the impact of the liquid leaving the impeller entering the pump casing immediately. Sometimes, the equipment has a fixed guide vane between the impeller and pump casing. The vane in the guide wheel makes the liquid entering the pump shell slowly turn into and continuously expand through the flow passage, so that part of the mechanical energy can be reasonably transformed into negative pressure energy. The guide wheel is generally installed for multi-stage submerged pump.
The small tortoise shaped pump shell, the backward curved blade on the impeller and the guide wheel can improve the conversion rate of mechanical energy to negative pressure energy, so they can be regarded as energy conversion equipment.
(3) The shaft seal equipment is fixed because of the rotation of the pump shaft, so there must be a certain gap between the shaft and the pump shell. In order to prevent the high pressure liquid in the pump from exposing along the gap, or to prevent the external gas from entering the pump in the opposite direction, it is necessary to set the shaft seal equipment. The shaft seal equipment of submerged pump has the sealing property of stuffing box and mechanical equipment (inner hole). The stuffing box is a sealing ring made by passing the pump shaft through the ring gap of the pump housing, in which soft packing (such as oil immersion or asbestos rope coated with high-purity graphite, etc.) is installed. The mechanical seal is composed of a moving ring installed on the transmission shaft and another static ring fixed on the pump housing. The inner holes of the two rings rotate relative to each other closely by elastic yellow force, which has the sealing effect. Machine seal is applicable to places with high sealing requirements, such as conveyor acid, alkali, inflammable, flammable, explosive and harmful liquid.