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What is the self-priming principle of diesel engine self-pri

Article provenance:Hai Rui ZhonglianPopularity:Publication time:2020-03-25 10:38

What is the self-priming principle of diesel engine self-priming pump?

The self-priming pump of diesel engine adopts the structure of axial return pump body, which is composed of suction chamber, liquid storage chamber, vortex chamber, return hole, gas-liquid separation chamber, etc. after the normal start of the pump, the impeller will inhale the liquid stored in the suction chamber together with the air in the suction pipeline, and completely mix in the impeller. Under the action of centrifugal force, the liquid conveyed the gas to the outer edge of the vortex chamber, and formed a thick white foam belt and a high-speed rotating liquid ring at the outer edge of the impeller. The gas-liquid mixture enters the gas-liquid separation chamber through the diffusion tube. At this time, due to the sudden decrease of the flow, the light gas and the mixed gas-liquid are separated, and the gas continues to rise, and is discharged through the ejection of the pump body. After degassing, the liquid returns to the liquid storage chamber, enters the impeller from the return hole, mixes with the gas drawn in from the suction pipe in the impeller, and flows into the outer edge of the impeller under the action of the high-speed rotating impeller. As this process is carried out again and again, the air on the suction line continues to reduce until the gas is absorbed and the self suction process is completed, then the pump can operate normally.

There is also a cooling chamber at the bottom of the bearing body of some pumps. When the bearing heat rises and the bearing body temperature rises more than 70 degrees, it can be cooled by circulating any coolant pipe joint in the cooling chamber. The sealing mechanism inside the pump is a front and rear sealing ring to prevent liquid leakage from the high pressure area to the low pressure area. The front seal ring is installed on the pump body, and the rear seal ring is installed on the bearing body. When the pump is worn for a long time, the seal ring will be worn to a certain extent, and it should be replaced when the pump efficiency and self-priming performance are affected.

The self-priming pump can be divided into the following categories according to its working principle:

1. Gas liquid mixing (including internal mixing and external mixing);

2. Water ring wheel type;

3. Injection type (including liquid injection and gas injection). Working process of gas-liquid mixed self-priming pump: due to the special structure of the pump body, when the pump stops running, there is a certain amount of water in the pump body. After the pump is started again, due to the rotation of impeller, the air and water in the suction pipeline are fully mixed and then discharged into the air-water separation chamber. The air in the upper part of the air-water separation chamber overflows, and the water in the lower part returns to the impeller. The residual air in the suction pipeline is re-s. Fry until all the gas in the pump and suction pipe is discharged, self suction is completed, and normal pumping is carried out. Water ring wheel self-priming pump is a shell composed of water ring wheel and pump impeller. With the help of water ring wheel, gas is discharged and self-priming is realized. When the water pump works normally, the passage between the water ring wheel and the water pump impeller can be cut off through the valve to discharge the liquid in the water ring wheel. The jet self-priming pump is composed of centrifugal pump and diesel self-priming pump (or injector), which is realized by the vacuum generated by the injection device at the nozzle.

According to the type of auxiliary power engine of the pump, it can be divided into motor auxiliary pump and diesel engine auxiliary pump.

According to the structure and working characteristics of self-priming function, it can be divided into internal sliding type, external sliding type, water ring wheel type and other types. The transmission mode includes direct connection transmission (including inner shaft) and belt transmission. The inlet diameter is 25-200 mm.