Apparatus for supplying feedwater to a steam generator

Claim 1

In an apparatus for supplying feedwater to a steam generator, such as a waste-heat boiler, degassing means for degassing water by heating the same to boiling temperature, supply conduict means communicating with said degassing means for supplying feedwater thereto to be degassed therein, discharge conduit means communicating with said degassing means for discharging degassed water therefrom, heat-exchanger means communicating with both of said conduit means for extracting heat from the degassed water and delivering the latter heat to the water which is to be degassed, said discharge conduit means communicating downstream of said heat-exchanger means with a steam generator for delivering degassed water thereto at a temperature less than the temperature of the water at the degassing means, supply bypass conduit means communicating with said degassing means for supplying feedwater thereto while bypassing said heat-exchanger means and discharging bypass conduit means communicating with said degassing means and said steam generator for delivering degassed water to the steam generator while bypassing said heat-exchanger means, both of said bypass conduit means carrying valve means for normally closing both bypass conduit means while said heat-exchanger means is used, said heat-exchanger means having a pair of inlets respectively connected with said discharge conduit means and supply conduit means for respectively receiving degassed water and water to be degassed, and said heat-exchanger means also having a pair of outlets respectively communicating with said discharge conduit means and supply conduit means for discharging cooled degassed water from said heat exchanger means and for discharging heated feedwater to be supplied to the degassing means, and valved means situated at each of said inlets and outlets for connecting said heat-exchanger means into and disconnecting the same from the supply and discharge conduit means.