Introduction To The Main Functions And Forms Of The Self-priming Device Of Centrifugal Pumps

Nov 07, 2024

There are many types of pumps such as centrifugal pumps, magnetic pumps, pipeline pumps, pumps, liquid pumps, etc. The common function of a self-priming centrifugal pump is that it does not have self-priming. In low-level use, self-priming is required. How can a self-priming centrifugal pump achieve this without any function? What are the functions and effects of self-priming devices, and what form do they take?
1, Why does the water pump require a self-priming device for operation?
From the above explanation, it can be seen that when the impeller rotates, only "textured" things can be thrown out from the center, forming a clear vacuum in the center. It is obvious that if the pump chamber is filled with air, no matter how fast it rotates, no vacuum can be formed. Therefore, before the centrifugal pump starts working, the pump chamber must be filled with liquid in advance, which is the origin of self-priming devices.
2,Basic principles of centrifugal pumps
The work of a pump is to utilize centrifugal force. When the pump chamber is filled with water, the impeller driven by the motor rotates at a fast speed, and the centrifugal force of the water scatters from the center to the surroundings. When the impeller hub forms a vacuum, the low-pressure impeller will flow outside the pressure of the liquid, so it will continuously pump the liquid to the outside world. The accumulation of liquid at the outlet under high pressure can be discharged from the inside of the high bypass valve at the bottom of the ship.
3, What are the teaching methods for self-priming devices?
Two common self-priming devices:
1. Using compressed air data to evacuate the pump casing and divert water
Before starting the pump, during the learning period of self-priming device design work, the valve on the outlet side should be kept closed by the enterprise, or a back pressure valve with spring action should be installed. When the outlet pressure can reach about 60% of the normal management working environment pressure, it should be automatically controlled to open. Vacuum suction must be connected to the highest point on the suction side of the pump and placed in the suction pipe to form an air chamber. Usually, a compressed air with reduced pressure is connected to the pump casing, and the Venturi tube effect is utilized to create a vacuum inside the pump casing and fill it with water. This technical device system allows the centrifugal pump to run dry for a short period of time.
2. The self-priming device is a self-contained vacuum pump
The disadvantage of using an emergency fire pump self-priming device is that the pump structure becomes more complex and the volume increases. Every time it is started, it ensures that the upper water tank is filled with water.