Difference between Self-priming pump and centrifugal pump

Ordinary centrifugal pump, if the water surface is under the impeller, it should be pre-filled when starting. In order to pump the water in the pump, the inlet of the suction pipe needs to be installed with the bottom valve. When the pump is working, the bottom valve causes a large hydraulic loss. The self priming trash pump is open. No need to fill the water before (the first time after installation, still need to be watered), after a short period of operation, the pump itself can suck up the water and put it into normal work. The working principle of the self priming sewage pump : 1. Gas-liquid mixing (including Internal mixing and external mixing): Due to the special structure of the self priming pump, after the pump stops, there is a certain amount of water in the pump body. After the pump is started again, the air in the suction pipe is fully mixed with water due to the rotation of the impeller. It is discharged into the gas-water separation chamber, the gas in the upper part of the gas-water separation chamber overflows, and the lower water returns to the impeller, and is re-mixed with the remaining air of the suction pipe until the gas of the pump and the suction pipe is completely discharged to complete self-priming, and the water is pumped normally. 2. Water ring wheel type self-priming pump: The water ring wheel and the pump impeller are combined in one casing, and the gas is discharged by the water ring wheel to realize self-priming. When the pump works normally, the water ring wheel can be cut through the valve. And the passage of the pump impeller, and let off the liquid in the water ring wheel. Flow self-priming pump: It is a combination of centrifugal pump and jet pump (or ejector). It relies on the spraying device to create vacuum at the nozzle to achieve suction.

Stainless steel self priming pump flow regulation 3 methods

If you want to adjust the flow rate of the stainless steel self-priming wet prime pump, you must follow a certain method, and you should not adjust it arbitrarily. Otherwise, it will affect the performance of the pump and have a great negative impact on the service life of the pump.

When we want to adjust the pump flow, we can adjust the flow of the centrifugal pump from the following three points:

(1) Install a regulating valve on the 6 inch trash pump outlet line to change the valve opening degree, that is, change the B value in the pipeline characteristic curve He=A+BQe2, the valve is opened, the working point is away from the vertical axis; the valve is closed, the following three The point can adjust the flow of the centrifugal pump, and the working point is close to the vertical axis.

Adjusting the flow rate of the stainless steel self priming pump, the advantage of this adjustment method is that it is easy and flexible to operate. The disadvantage is that when the valve is closed, the resistance in the pipeline is increased, and the energy loss is increased, so that the pump cannot work in the highest efficiency region, which is uneconomical. The method of changing the valve opening degree to adjust the flow rate is often used when the flow adjustment range is not large and the adjustment is often required.

(2) Change the speed of the engine driven trash pump, that is, change the characteristic curve of the pump.

(3) The outer diameter of the turning impeller also changes the characteristic curve of the pump.

The flow rate of the centrifugal pump can be changed by the above two methods. Using these methods to adjust the flow rate within a certain range can ensure that the pump works in a high efficiency zone. The energy utilization is economical, but inconvenient, and the flow regulation range is not large, so the application is not extensive.