GB587174A - Boiler feed system - Google Patents

Abstract

587,174. Feedwater supply systems. WATERMAN, R. R. July 19, 1944, No. 13851. [Class 123 (ii)] [Also in Group XXIX] Feedwater is supplied to a steam boiler 1, particularly of the flash type, by a pump 6 which has an inlet 7 and outlet 8 and is coupled to a steam-operated driving member 5 which is located in a bye-pass 18, 20 of the steam outlet pipe 12 of the boiler in such a manner that it will operate the pump only when the throttle valve 16 in the main outlet pipe of the boiler is open. An adjustable pressure relief valve 17 is interposed in the steam pipe 12 between the supply and exhaust pipes 18, 20 of the driver 5 to reduce the steam pressure in said pipe 12 down to that in the exhaust pipe 20, and the supply pipe 18 is fitted with orifice 19 of restricted size so that the speed of the pump will vary in accordance with the wetness of the steam generated. The boiler may be heated by a gas burner 3, the supply of gas to which is controlled by a valve 9 in the outlet pipe 8 of the pump 6. Fig. 3 shows a construction of relief valve 17 comprising a vertical tubular body 21 which is finned at 22 for heat radiation and houses a piston valve 23 normally pressed by a spring 25 against a seat 24 on the lower end of the high pressure inlet portion of the pipe 12, the low pressure outlet portion of the latter opening into the body 21 at the normal position of the central portion of the valve. The spring 25 is adjustable by meansof a backing plug 26 screwed into the lower end of the body 21, and the valve is ported at 27 so that steam may flow into the part of the body locating the spring where it will condense to maintain the spring relatively cool.