Four suggestions for liquid ring vacuum pump selection

1, liquid ring vacuum pump should try to choose a lower speed of the specification
At present, the application of liquid ring vacuum pump is at most 2 bv series, belongs to the axial suction exhaust single-acting pumps, for the same specifications have multiple speed to choose, when the inlet pressure 200 hPa and 600 hPa, exhaust pressure of 800 hPa and 1013 hPa, the impeller blades of cylindrical linear velocity for 14 ~ 17 m/s, so because of the large impeller diameter of pump speed of large size is low, so under the premise of same swept volume, should choose as far as possible speed lower pump, large pump than smaller power consumption, high efficiency.
In addition, the larger size of the liquid ring vacuum pump is due to the blade length is the flow channel length, the curvature of the fluid is small, the flow line is approximately straight, the flow of the fluid is close to the slow variable flow, the flow of the secondary eddy and boundary layer caused by the fluid flow energy loss is also small.
2, liquid ring vacuum pump should consider the influence of water temperature
At home and abroad because of the liquid ring vacuum pump performance curve on the technical documents and technical data are based on the premise of inlet water temperature of 15 ℃, the front has also introduced the water temperature below 15 ℃ or higher than the temperature influence coefficient calculation formula of gas.
Therefore, the influence of actual water temperature on gas volume should be fully considered when selecting liquid ring vacuum pump. Because our country most users added water temperature is between 25 ℃ and 35 ℃. Therefore, the selection of pump than the technical documents on the appropriate increase in gas volume.
3. Influence of suction resistance of liquid ring vacuum pump
Because of gas suction location often below the bleak look-out, liquid ring vacuum pump is far away, thousands of meters) of (some coal mines in suction pipe line is too long, therefore, inspiratory resistance loss should be considered, and the coal mine system by using the formula for calculating the suction resistance is calculated, the coarser should be adopted when arranging pipeline suction pipe, reducing the loss of resistance, and try to reduce the right-angle bend, in order to achieve the purpose of improving the efficiency of inspiratory.
4, liquid ring vacuum pump exhaust with micro positive pressure when the selection
At present, some coal mines need to discharge the extracted gas to a distant place or compress it into the gas storage tank, and the exhaust pressure is generally between 0.02-0.05mpa ·G. Since the performance curves and technical data in the technical documents of the liquid ring vacuum pump are all obtained under the exhaust pressure of 1 standard atmosphere, the influence of the rising exhaust pressure and the increase of the backflow inside the pump chamber on the amount of exhaust gas should be considered in the selection of the model.
In addition, as the exhaust pressure increases, the shaft power of the pump increases, the power of the matching driver should also increase, in this case, the manufacturer should provide the test performance curve and corresponding technical data in the selection, in order to fully meet the requirements of the user.
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