What Are The Types Of Impellers For Coal Slurry Pumps?

Oct 29, 2024

The concept of impeller: The impeller refers to both the disc with moving blades, which is a component of the impulse turbine rotor, and the general term for the disc and the rotating blades installed on it. The impellers are commonly cast or welded, and the material is selected according to the working medium.

impeller

Main function: The impeller converts the mechanical energy of the prime mover into static and dynamic pressure energy of the working fluid. It is to directly transfer the mechanical energy of the prime mover to the liquid, in order to increase the static pressure energy and kinetic energy of the liquid, mainly to increase the static pressure energy. The impeller generally has 6-12 trailing blades. The impeller of the water pump is driven to rotate by an electric motor, creating a vacuum in the middle of the impeller. Water flows into the vacuum area (on the surface, the impeller continuously sucks in water), and then the water is discharged through the high-speed rotating impeller, playing a role in pushing water.

Type of impeller for coal slurry pump

1. Impeller structure type: The impeller structure is divided into four categories: blade type (open, closed), swirl type, channel type, (including single channel and double channel) spiral centrifugal type. The open semi open impeller is easy to manufacture and can be easily cleaned and repaired when blockage occurs inside the impeller.

The semi open and open impellers in blade type impellers are easy to cast and maintain, as well as clean impurities that may clog during transportation. However, its drawbacks lie in the increased gap between the inner wall of the pressurized water chamber and the blades due to the erosion of solid particles during transportation, which reduces the operating efficiency of the water pump. Moreover, the increased gap disrupts the stability of the liquid flow in the channel, causing the pump to vibrate. This type of impeller is not easy to transport media containing large particles and long fibers. The enclosed impeller has high operating efficiency and can run smoothly for a long time. The axial thrust of the pump is small, but the enclosed impeller is prone to entanglement and difficult to transport sewage media containing large particles or long fibers.

2. Swirl impeller: Pumps using this type of impeller have some or all of the impeller retracted from the pressure chamber flow channel. So the non clogging performance is good, and the particles flow in the water pressure chamber driven by the vortex generated by the rotation of the impeller. The movement of suspended particles itself does not generate energy, and energy is exchanged between the flow channel and the liquid. During the flow process, suspended particles or long fibers do not come into contact with the worn blades. The situation of excessive blade wear is relatively mild, and there is no increase in gaps due to abrasion. It is suitable for pumping media containing large particles and long fibers.

3. Closed impeller: This type of impeller has a higher normal efficiency. And in long-term operation, the situation is relatively stable. Pumps using this type of impeller have smaller axial forces and can be equipped with auxiliary blades on the front and rear cover plates.

4. Flow channel impeller: This type of impeller belongs to bladeless impellers, and the impeller flow channel is a curved flow channel from the inlet to the outlet. Good anti blocking performance, in terms of performance, this type of impeller has high efficiency and is not much different from ordinary closed impellers. The power curve is relatively stable, and it is not easy to produce high-power problems. This type of impeller is suitable for conveying liquids containing large particle impurities or long fibers. Because this type of impeller has excellent anti clogging performance. But its drawback is that its anti cavitation performance is weaker than other forms.

5. Spiral centrifugal impeller: The blades of this type of impeller are twisted spiral blades that extend axially from the suction port on a conical hub body. This type of impeller pump has both the functions of a positive displacement pump and a centrifugal pump. When suspended particles flow through the blades, they do not hit any part of the pump, so it has good non-destructive properties. When the liquid being transported flows through the blades, it does not collide with any part of the pump, so there is no damage to the water pump. At the same time, there is no destructive effect on the liquid being transported. Due to the propulsion effect of the spiral, the passage of suspended particles is strong. Therefore, pumps using this type of impeller are suitable for pumping media containing large particles and long fibers.