Characteristics and differences between self priming pump and centrifugal pump
Click:9854 Date:2013-07-16 15:41:00 Information Source:
The main difference between self-priming pump and centrifugal pump is that the inlet pipe of self-priming pump can suck up the water without filling the bottom valve for the first time, and no further water is needed later. The pump body is much larger than the centrifugal pump with its own water storage function, and has the function of one-time water diversion and lifelong self-priming, while the centrifugal pump is pressurized. If the liquid level is lower than that of a centrifugal pump, it can only be self-primed by installing a bottom valve at the inlet pipe suction port to fill the pump and pipe with liquid, or by installing a water intake cylinder at the inlet, such as a centrifugal pump that does not work for a long time, and by importing the pipe at the second start-up. And the water inside the pump body is basically no longer, and have to be filled again to water, the operation is more troublesome, because a long time does not use the centrifugal pump inlet bottom valve seal can not achieve the effect of complete sealing liquid will slowly leak back to the pool, so in the need for self-priming function of the working conditions of self-priming pump than centrifugal pump, and in the swimming pool better effect. Self priming pumps are widely used in water treatment equipment.
Self suction pumps and centrifugal pumps all use axial return pump body structure. The centrifugal pump body is composed of suction chamber, storage chamber, scroll chamber, return hole, gas-liquid separation chamber, etc. After the normal start-up of the centrifugal pump, the impeller will suck the liquid in the suction chamber and the air in the suction pipe together, and mix completely in the impeller. Under the action of centrifugal force, the liquid entrains the gas to the outer edge of the scroll chamber. A white foam belt and a high speed rotating liquid ring are formed on the outer edge of the impeller. The gas-liquid mixture enters the gas separation chamber through the diffusion tube. At this point, due to a sudden decrease in the flow rate, the lighter gas is separated from the mixed liquid, and the gas continues to rise and discharge through the pump outlet. After degassing, the liquid returns to the reservoir, and enters the impeller again by the return hole, mixes again with the gas inhaled from the suction pipe inside the impeller, and flows to the outer edge of the impeller under the action of the high-speed rotating impeller. As the process continues, the air in the suction pipe decreases until the air is sucked out, the self-priming pump completes the self-priming process and the centrifugal pump is put into normal operation. Because the centrifugal pump has this unique exhaust capacity, so this self-priming pump can transport liquid containing gas, without the installation of bottom valves, used on cruise ships with good sweeping function.
A cooling chamber is provided at the bottom of the bearing body of some centrifugal pumps. When the bearing heating causes the temperature of the bearing to rise more than 70 degrees Celsius, a coolant pipe joint can be passed in the cooling chamber and injected as coolant for circulating cooling. The sealing mechanism of centrifugal pump to prevent liquid leakage from high pressure area to low pressure area is front and back sealing ring. The front sealing ring is mounted on the pump body and the rear sealing ring is mounted on the bearing body. When the pump runs for a long time, the sealing ring is worn to a certain extent and affects the pump efficiency and self-priming performance, it should be replaced.
The centrifugal pump is usually driven by an electric motor. Before starting the pump, the pump body and suction line are filled with liquid. When the impeller rotates at high speed, the impeller drives the liquid between the blades to rotate together. Due to the centrifugal force, the liquid is thrown from the center of the impeller to the outer edge of the impeller (the flow rate can be increased to 15-25m/s), and the kinetic energy increases accordingly. When the liquid enters the pump shell, the flow path in the volute pump shell expands gradually, the liquid velocity decreases gradually, and part of the kinetic energy changes into static pressure energy, so the liquid flows out along the outlet at a higher pressure. At the same time, a certain vacuum is formed at the center of the impeller due to the liquid being thrown out, and the pressure Pa at the surface is higher than that at the center of the impeller. Therefore, the liquid in the suction pipeline enters the pump under the action of pressure difference. The impeller keeps spinning, and the liquid is continuously inhaled and pressed. Because centrifugal pumps can transport liquids, they are mainly centrifugal pumps, so they are called centrifugal pumps.
Self suction pumps and centrifugal pumps all use axial return pump body structure. The centrifugal pump body is composed of suction chamber, storage chamber, scroll chamber, return hole, gas-liquid separation chamber, etc. After the normal start-up of the centrifugal pump, the impeller will suck the liquid in the suction chamber and the air in the suction pipe together, and mix completely in the impeller. Under the action of centrifugal force, the liquid entrains the gas to the outer edge of the scroll chamber. A white foam belt and a high speed rotating liquid ring are formed on the outer edge of the impeller. The gas-liquid mixture enters the gas separation chamber through the diffusion tube. At this point, due to a sudden decrease in the flow rate, the lighter gas is separated from the mixed liquid, and the gas continues to rise and discharge through the pump outlet. After degassing, the liquid returns to the reservoir, and enters the impeller again by the return hole, mixes again with the gas inhaled from the suction pipe inside the impeller, and flows to the outer edge of the impeller under the action of the high-speed rotating impeller. As the process continues, the air in the suction pipe decreases until the air is sucked out, the self-priming pump completes the self-priming process and the centrifugal pump is put into normal operation. Because the centrifugal pump has this unique exhaust capacity, so this self-priming pump can transport liquid containing gas, without the installation of bottom valves, used on cruise ships with good sweeping function.
A cooling chamber is provided at the bottom of the bearing body of some centrifugal pumps. When the bearing heating causes the temperature of the bearing to rise more than 70 degrees Celsius, a coolant pipe joint can be passed in the cooling chamber and injected as coolant for circulating cooling. The sealing mechanism of centrifugal pump to prevent liquid leakage from high pressure area to low pressure area is front and back sealing ring. The front sealing ring is mounted on the pump body and the rear sealing ring is mounted on the bearing body. When the pump runs for a long time, the sealing ring is worn to a certain extent and affects the pump efficiency and self-priming performance, it should be replaced.
The centrifugal pump is usually driven by an electric motor. Before starting the pump, the pump body and suction line are filled with liquid. When the impeller rotates at high speed, the impeller drives the liquid between the blades to rotate together. Due to the centrifugal force, the liquid is thrown from the center of the impeller to the outer edge of the impeller (the flow rate can be increased to 15-25m/s), and the kinetic energy increases accordingly. When the liquid enters the pump shell, the flow path in the volute pump shell expands gradually, the liquid velocity decreases gradually, and part of the kinetic energy changes into static pressure energy, so the liquid flows out along the outlet at a higher pressure. At the same time, a certain vacuum is formed at the center of the impeller due to the liquid being thrown out, and the pressure Pa at the surface is higher than that at the center of the impeller. Therefore, the liquid in the suction pipeline enters the pump under the action of pressure difference. The impeller keeps spinning, and the liquid is continuously inhaled and pressed. Because centrifugal pumps can transport liquids, they are mainly centrifugal pumps, so they are called centrifugal pumps.
