A reciprocating vacuum pump (also known as a piston vacuum pump) is one of the low vacuum acquisition equipment. Its ultimate pressure is generally between 1330 and 2660Pa, and its pumping speed range is relatively large, from 50L/S to 200L/S. It is suitable for vacuum impregnation, steel vacuum treatment, vacuum distillation, vacuum evaporation, vacuum concentration, vacuum crystallization, vacuum drying, vacuum filtration, and vacuum operation of concrete in industries such as petroleum, chemical, pharmaceutical, food, light industry, metallurgy, and electrical engineering.
Reciprocating vacuum pumps are not suitable for extracting gases with high oxygen content, explosive properties, corrosion to metals, chemical reactions with pump oil, or gases containing particulate dust. They are also not suitable for transporting gases from one container to another as pumps.
The main components of a reciprocating vacuum pump are the cylinder and the piston that moves back and forth in a straight line. The drive of the piston is achieved through a crank connecting rod mechanism. In addition to the main components mentioned above, there are also important components such as exhaust valves and suction valves, as well as auxiliary components such as the engine base, crankcase, dynamic seals, and static seals.
During operation, driven by an electric motor, the piston in the cylinder undergoes reciprocating motion through the action of the crank connecting rod mechanism (rotating motion is converted into linear motion). When the piston moves from the left end to the right end in the cylinder, due to the continuous increase in the volume of the left chamber of the cylinder, the pressure in the left chamber space decreases. When the pressure in the left chamber space is lower than that in the container being drawn, according to the principle of gas pressure balance, the gas in the container being drawn is continuously drawn into the left chamber through the suction valve 5, and at this time, it is in the process of suction. When the piston reaches its rightmost position, the left chamber of the cylinder is filled with gas. Then the piston moves from the right end to the left end, and the suction valve automatically closes. The gas is gradually compressed as the piston moves from right to left. When the gas in the cylinder reaches the exhaust pressure, the exhaust valve is opened and the gas is discharged, completing a working cycle. When the piston moves from the left end to the right end, repeat the above cycle until the container being pumped reaches a certain equilibrium pressure.
In reciprocating pumps, the suction valve and exhaust valve are very important and vulnerable components, and their performance directly affects the ultimate pressure, pumping rate, power consumption, and reliability of operation of the reciprocating pump.
