Detailed Explanation of 20 Different Pump Types(9)

                                Detailed Explanation of 20 Different Pump Types(9)

9、 Water ring vacuum pump

The impeller is eccentric to the pump casing, and a certain amount of water is filled inside the pump casing. The rotation of the impeller forms a water ring. When adjacent blades (as shown in the red blade in the figure) rotate, the space (air chamber) formed with the water ring becomes larger, indicating air intake, while the air (air chamber) gradually becomes smaller, indicating that the air is compressed. Multiple sets of adjacent blades, i.e. multiple sets of reciprocating compression. Due to its compact structure, reliable working balance, and uniform flow rate, it is commonly used in chemical production to transport or extract flammable, explosive, and corrosive gases. The water ring vacuum pump has low efficiency due to the large energy loss caused by the impeller stirring the liquid.

Performance characteristics:

Advantages: Simple structure, low manufacturing accuracy requirements, easy processing. Compact structure, high rotation speed of the pump, generally can be directly connected to the electric motor without the need for a deceleration device. Therefore, using a small structural size can achieve a large exhaust volume and a small footprint. Compressed gas is essentially isothermal, meaning that the temperature change during the compression process is minimal. Due to the absence of metal friction surfaces in the pump chamber, there is no need for lubrication inside the pump, and the wear is minimal. The sealing between the rotating and fixed parts can be directly achieved by a water seal. Uniform inhalation, stable and reliable operation, simple operation, and convenient maintenance.

Disadvantages: Low efficiency, usually around 30%, with better ones reaching up to 50%. The low vacuum degree is not only due to structural limitations, but more importantly, it is limited by the saturated vapor pressure of the working fluid. Using water as the working fluid can only achieve a maximum pressure of 2000-4000 Pa. Using oil as the working fluid can reach up to 130 Pa. In short, due to the isothermal compression of gas in the water ring pump, flammable and explosive gases can be extracted. Due to the absence of exhaust valves and friction surfaces, dust laden gases, condensable gases, and gas water mixtures can be extracted. With these outstanding features, despite its low efficiency, it has still been widely applied.