Vacuum Catalogue - Edwards

Liquid Ring Pump Applications in Power MarketLiquid ring pumps are ideally suited for use in a number of vacuum applications in power generation, all of which benefit from the performancecharacteristics of liquid ring vacuum pumps.• Condenser Air Extraction• Waterbox Priming• Flue Gas Desulphurisation• Fly Ash HandlingCondenser air extraction and waterbox priming both contribute to increased efficiency of the power plant, whilst flue gas desulphurisation and flyash handling are both to do with treatment of the boiler exhaust gas.Typical coal fired power plantEdwards have developed a range of standard pump packages to meet the vacuum pumping requirements for each of these applications.Condenser Air ExtractionIn order to increase the availability, operational performance and reliability of turbine condenser vacuum plants, the dynamic relationship betweenthe vacuum pumping system, condenser performance and turbine back pressure is an important factor in the design requirements and needscareful appraisal when considering overall plant performance.Selection of the vacuum equipment is usually based upon a theoretical condition, with performance requirements taken from HEI (or VGB)recommendations. Client specifications require further analysis of pump performance at actual operating temperatures and pressures, includingpart load and operation with alternate fuels.Edwards condenser air extraction packages, based on two-stage liquid ring vacuum pumps, are designed to remove system air leakage fromsteam turbine generator surface condensers systems, helping the turbine efficiency to be maintained. This is achieved by reducing the pressurein the turbine, enabling more heat from the steam to be converted to mechanical energy, thereby increasing the output of the power plant.The air load from the turbine condenser system is saturated with vapour: liquid ring pumps are ideal for handling high vapour loads as much ofthe vapour will be condensed at the pump suction (by the direct condensing action of the inlet water spray or contact with the pump seal water).This condensing reduces the total volume to be handled by the pump, which is a significant advantage when compared to other pumpingtechnologies.Edwards have developed a range of standard packages based upon the SHR series of two stage liquid ring pumps. The packages are designedto meet air leakage rates in the HEI Standards for Steam Surface Condensers.10Page399Shop online at www.edwardsvacuum.com