Liquid ring vacuum pumps have been used for many years to remove air from steam surface condensers and industrial processes. It is one of the simplest and most reliable methods of pumping.
A typical vacuum pump exhaust system for a steam condenser consists of two identical 100% capacity vacuum pumps. It is common practice to use two vacuum pumps simultaneously to empty or “hold” the condenser to a position where steam can be introduced into the turbine, then turn off one vacuum pump while the other enters “hold mode” to continuously remove the condenser from the condenser during operation of the air turbine.
In exhaust applications, liquid ring vacuum pumps are used to remove air and any other non condensable gases from the steam space serving the main condenser of the steam turbine. The purpose of this kind of gas removal is to eliminate the insulation effect of non condensable gas on heat transfer from steam through pipe to cooling medium. If there is no vacuum system, air will seriously reduce the heat transfer efficiency, resulting in the condenser surface area increased many times under a given steam load.
Vacuum pump exhauster is usually a two-stage vacuum pump. For operation, the first stage is used to vent high absolute pressure air and the second stage is bypassed to optimize efficiency and reduce peak horsepower demand. Both systems operate automatically to empty the condenser to the required pressure of the turbine. At this point, the system pressure switch sends a signal to turn off the “lag” pump, while the “pilot” pump continues to operate in hold mode. At a pressure of about 20 inches of HGV, the second stage of the vacuum pump starts to operate effectively, and the interstage bypass check valve is closed to allow the two-stage pump to operate.
The single-stage high performance liquid ring vacuum pump can withstand a vacuum of up to 29 inches of mercury. These API vacuum pumps have a variable discharge design that automatically adjusts to the internal compression ratio of the vacuum pump to achieve maximum efficiency over the entire vacuum range. Advanced fluid dynamics enables high volumetric efficiency with a 50% reduction in sealing fluid requirements.
We have developed a series of liquid ring condenser exhaust devices and vacuum pump systems to meet the needs of various industries.