Abstract: In a once-through steam generator, a separating bottle (25) is inserted between the evaporator (22) and the superheater (23). To purify the water/steam circuit, a greater quantity of water than is necessary is conveyed through the evaporator (22) via a feed pump (20). The water quantity is measured in such a way that wet steam enters the separating bottle (25). This water fraction, together with all the impurities contained therein, is separated in said bottle and is drawn off via a blowdown line (29). On the occasion of overfeeding, a conditioning agent is metered to the water, in order to reduce the volatility of the substances to be separated.

Abstract: In a combined gas/steam power plant with a once-through forced-flow steam generator, a separation bottle (25) is connected between the evaporator (22) and the superheater (23). To clean the water/steam circuit, in the full-load or the part-load mode, a larger quantity of water than necessary is conveyed through the economizer (21) and the evaporator (22) via a feed pump (20). The quantity of water is selected such that wet steam passes into the separation bottle (25). This water fraction, together with all the impurities contained therein, is separated in the separation bottle and is drawn off via a clarifying line (29). Overfeeding can be regulated in such a way that the fresh steam temperature corresponds to the nominal value of the respective load point. When cleaning of the water/steam circuit is intended in the full-load mode, and without overfeeding the system, steam from a stage of incomplete evaporation can be extracted out of the evaporator and led into the separation bottle.

Abstract: A multi-pressure waste-heat boiler (7) comprises at least one circulation steam generator, having a low-pressure economizer (15), a low-pressure drum (17) and a low-pressure evaporator (16), and at least one once-through steam generator having a high-pressure economizer (21), a high-pressure evaporator (22) and a high-pressure superheater (23). An oxygen addition (32) is arranged between the steam drum (17) of the circulation steam generator and the high-pressure economizer (21) of the once-through steam generator. An ammonia addition (31) is arranged in the feed line (33) leading to the circulation steam generator.

Abstract: A mixed-pressure waste-heat boiler (7) has a forced-flow steam generator, essentially composed of a low-pressure economizer (15), of a low-pressure drum (17) and of a low-pressure evaporator (16), and a once-through forced-flow steam generator, essentially composed of a high-pressure economizer (21), of a high-pressure evaporator (22) and of a high-pressure superheater (23). The high-pressure economizer (21) is fed from the steam drum (17) of the forced-circulation steam generator via a high-pressure feed pump (20). Arranged between the high-pressure evaporator (22) and high-pressure superheater (23) is a separation bottle (25) which is connected to the steam drum (17) via a recirculation line (26). During startup, until superheated conditions are reached at the outlet of the high-pressure evaporator (22), high-pressure saturated water is recirculated into the drum (17) of the forced-circulation steam generator via the separation bottle (25).