【Abstract】：
1. Working principle of positive displacement pump (rotary type)
The power is transmitted to the gears through the shaft, and a pair of synchronous gears drive the pump blades to perform synchronous reverse rotation movement, so that the inlet area produces a real mouth, and the medium is sucked down. With the rotation of the pump blades, the medium is sent to the outlet and continues to rotate, leaving the mouth volume It becomes smaller and generates pressure (outlet high pressure area) to output the medium. Because the high-viscosity medium with a low rotation speed of the positive displacement pump, strong self-priming ability and poor flow performance has sufficient time and speed to fill the cavity, this type of pump is suitable for high-viscosity medium. Sealing surface inside the pump. The diarrhea is small, so the efficiency of the pump is high, which can reach more than 70%. At the same time, it can achieve high-pressure delivery of media, and it has good adaptability to media with lower viscosity.
1. Working principle of positive displacement pump (rotary type)
The power is transmitted to the gears through the shaft, and a pair of synchronous gears drive the pump blades to perform synchronous reverse rotation movement, so that the inlet area produces a real mouth, and the medium is sucked down. With the rotation of the pump blades, the medium is sent to the outlet and continues to rotate, leaving the mouth volume It becomes smaller and generates pressure (outlet high pressure area) to output the medium. Because the high-viscosity medium with a low rotation speed of the positive displacement pump, strong self-priming ability and poor flow performance has sufficient time and speed to fill the cavity, this type of pump is suitable for high-viscosity medium. Sealing surface inside the pump. The diarrhea is small, so the efficiency of the pump is high, which can reach more than 70%. At the same time, it can achieve high-pressure delivery of media, and it has good adaptability to media with lower viscosity.
2. Classification and characteristics of positive displacement pump
Positive displacement pumps are divided into two types: reciprocating and rotary. Compared with reciprocating positive displacement pumps, rotary positive displacement pumps have no suction and discharge valves, and they will not be like reciprocating pumps. Normal work has an effect, and the pump efficiency decreases rapidly as the viscosity increases. In addition, when the viscosity of the conveyed liquid is increased, the decrease of the pump speed is smaller than that of the reciprocating pump. Therefore, when conveying a high-viscosity liquid or when the viscosity of the liquid changes greatly, the rotary solvent pump is more suitable than the reciprocating positive displacement pump. Rotary displacement pumps are divided into gear pumps, rotary piston pumps, screw pumps, and sliding vane pumps. It has the characteristics of low rotation speed, high efficiency, strong self-priming ability, stable operation, and some pumps can be preheated. It is widely used in the transportation of highly viscous media. Disadvantages: large area, large investment in construction, large volume and heavy weight.
