vacuum unit for the reduction of pumping capacity of reasons

The vacuum unit retains the advantages of rapid operation of Roots pump and relatively large pumping rate. What is the reason for the reduced air extraction capacity of this equipment? The following is the arrangement of the minor editor:

There are many reasons for vacuum units to reduce air extraction, such as failing to reach the rated speed, excessive end clearance, stuffing box leakage, insufficient water supply, liquid ring heating, excessive radial clearance of single acting pump, scale, etc.

Among the above reasons, excessive end clearance is an important and common reason for insufficient air flow. If the position of the impeller on the pump body is not inclined, that is, the excessive end clearance is not caused by the wear between the impeller and the side cover, then the excessive gasket should be removed.

The radial clearance between the impeller load and the water ring of the single acting pump is the place where the gas leakage is large. If the gap is too large, the gas volume will decrease too much. Therefore, the make-up water can be injected into the pump body or side cover corresponding to the radial clearance to fill the excessive radial clearance. At this time, the pressure of make-up water should be more than 1.2kg/cm2, otherwise it cannot enter. These should be considered in the design.

When the vacuum unit uses hard water with high hardness, scaling is very serious. The incrustation on the blade is thickened, which will inevitably reduce the effective space and partially block the suction and discharge holes, resulting in the reduction of gas volume. The way to eliminate scale is to soften the hard water before use. For parts with oxide scale, mechanical method or acid solution washing method can be used to reduce the influence of oxide scale.

When the vacuum unit is dry, use the water ring pump for pre pumping until its water vapor is greatly reduced, then start the pneumatic mechanical manual dry oil pump to cut off the water ring pump. I hope the above content is helpful to you.