How to Control Liquid Ring Vacuum Pumps （如何控制液环真空泵）.PDF

How to Control Liquid Ring Vacuum Pumps BY JOE ALIASSO iquid ring vacuum pumps are versatile machines because they flammable or hazardous, then a reflex gauge should be used over a Lcan handle “wet” loads and can operate down to around 1” tubular glass type. This will provide better protection from break- HgA. They require proper operation and monitoring, however. age, which would result in fluid in the tank leaking out. This article will address several monitoring and troubleshooting situations involving liquid ring vacuum pumps (Figure 1). The liquid ring pump usually handles a “wet” or condensable load. Vapors will condense in the pump and be discharged into A check valve will prevent a backflow of gases at start-up or shut- the separator. This will produce excess fluid in the separator. The down of the system. When choosing a check valve, a low pressure simplest way to maintain a constant level in the separator is to drop type should be considered to minimize pressure loss in the have an overflow connection on the separator tank. This will system. A butterfly style check valve normally has the lowest pres- drain excess fluid. If make-up is needed, then usually a manual sure drop. valve is installed. If automatic make-up is required, a float operat- ed valve can be used. This, along with the overflow connection, Typically for pressures of 100 mmHgA and less, some sort of will maintain a constant level in the separator. If remote monitor- anti-cavitation or suction pressure control is needed. The simplest ing and automatic control is required, then level switches and type is a manual bleed valve such as