A forced circulation steam boiler with heating tube installed in the boiler flue for generating steam for de-aeration of the boiler feedwater

摘要

1,010,336. Forced flow steam boilers; feedwater supply systems. TAKUMA KIKAN SEIZO KABUSHIKI KAISHA. Aug. 8, 1962 [Dec. 1, 1961], No. 30452/62. Heading F4A. A forced circulation steam boiler has a heating tube 19 located in the boiler flue and wet steam generated therein is conveyed through a line 21 to a deaerator 3 to be used as the heat source in the deaeration of the boiler feedwater. A deaerator pump 1 delivers feedwater through a heat exchanger 2 heated by the blow down from the boiler, through a further heat exchanger 4 disposed in the deaerator and through a level control valve 6 the deaerator. Deaerated feedwater is delivered by a feedwater pump 8 into an annular compartment 10 within a steam and water separator 9, an outlet in the lower end of this compartment allowing feedwater to mix with the recirculated water in a mixing chamber 11 of the separator. A circulating pump 15 circulates water drawn from the mixing chamber 11 through evaporating tubes 16 located in a combustion chamber and steam is taken off through a line 18. Feedwater is supplied to the heating tube 19 from the chamber 10 through an overflow control device 20, e.g. a steam trap.