Improvements in or relating to forced-flow, once-through steam boilers

摘要

919,980. Feedwater supply systems for steam boilers. PRVNI BRNENSKA STROJIRNA ZAVODY KLEMENTA GOTTWALDA NARODNI PODNIK. Jan. 1, 1960, No. 103/60. Class 123 (2). The tube system of a once-through boiler 1 supplied with feed-water through a pipe 5 by a pump 4 drawing water from a container 2 maintained under pressure is protected from being dried out and overheated by the residual heat in the boiler setting in the event of failure of the main pump 4 by a throughflow of water coming direct from the pressure container 2 through a pump by-pass pipe 8 to the boiler inlet. Non- return clapper valves 7, 9 in the pipes 5, 8 serve automatically to close the pump delivery and open the by-pass on pump failure. In a modification an auxiliary pump operates to increase the flow to the boiler in the event of main pump failure. In a further modification the by-pass pipe is omitted and an independent supply of feedwater stored under pressure flows into the main feed supply pipe 5 on pump failure.