Submerged pump is a vertical pump in which the impeller, pump body and other flow components are immersed in the conveyed material and connected to the motor shaft. The submersible pump is made according to different requirements for the length of insertion into the container. The components of the submersible pump that come into contact with the material are generally selected according to the requirements of the material, including metal and non-metal materials. The key components of the submersible pump are as follows:

1. Impeller

The impeller is the core component of the submersible pump.

According to its mechanical structure, it can be divided into three types: closed, semi closed, and open. Closed impeller suitable for conveyor cleaning liquid; Semi closed and open impellers are suitable for mixed liquids with solid particles in conveyors, but their high efficiency is low.

According to different suction methods, impellers can be divided into single suction and double suction types. The single suction impeller has a simple structure, and the liquid can only be sucked in from one side. The double suction impeller can also symmetrically suck in liquid from both sides of the impeller. It not only has a great suction capacity, but also largely removes radial thrust.

According to the geometric shape of the blades on the impeller, the blades can be divided into three types: backward bending, axial bending, and forward bending. Because backward curved blades are beneficial for converting the mechanical energy of liquids into negative pressure energy, they are widely used; Axial blades are key applications in some flow pumps and unobstructed pumps; Forward curved blades are rarely used in submersible pumps.

2. Guide vanes and pump casing

In order to reduce the kinetic energy damage caused by the impact of the liquid leaving the impeller immediately entering the pump casing, a fixed guide wheel containing blades is sometimes installed between the impeller and the pump casing. The blades in the guide wheel gradually convert the liquid entering the pump casing into and continuously expand the flow channel, allowing a portion of the mechanical energy to be reasonably converted into negative pressure energy. Multi stage submersible pumps are generally equipped with guide wheels.

The small turtle shaped pump casing, the rear curved blades on the impeller, and the guide wheel can all improve the conversion rate of mechanical energy to negative pressure energy, so they can all be regarded as energy conversion devices.

3. Shaft sealing equipment

Because the pump shaft rotates while the pump casing remains fixed, there will inevitably be a certain gap at the contact between the shaft and the pump casing. To prevent high-pressure liquid from being exposed along the gap in the pump or to prevent external gas from entering the pump from the opposite direction, it is necessary to set up a shaft seal device. The shaft sealing equipment of the submersible pump includes a packing box and mechanical equipment (inner hole) for sealing. Packing box is a sealing ring made by passing the pump shaft over the annular gap of the pump casing, and then inserting soft packing (such as asbestos rope soaked in oil or coated with high-purity graphite) into it. A mechanical seal is composed of a moving ring mounted on the transmission shaft and another stationary ring fixed on the pump casing. The inner holes of the two rings tightly adhere to each other and rotate relative to each other by the force of elasticity, providing a sealing effect. Machine seals are suitable for places with high sealing requirements, such as conveyor acid, alkali, flammable, explosive, and harmful liquids.