GB624722A - Improvement in waste heat steam boilers - Google Patents

Abstract

624,722. Heating steam boilers by waste gases. TRIGGS. W. W. (Maxim Silencer Co.). Nov. 6, 1946, No. 33009. [Class 123(ii)] A waste heat steam boiler, e.g. in the form of a jacket 21 surrounding an internal combustion engine exhaust silencer 11, adapted to run dry when there is no steam demand, has feed-water supply and return or drain pipes 40, 41 which lead through a common pipe 42 to a spring pressed valve 34 which is actuated by the boiler steam pressure to control the pipe 42 and also pipes 43 and 46 leading from and to a feedwater supply tank 29. The pipes 40, 41 are provided with check valves 38, 39 respectively which permit flow therethrough in the direction of the arrows, and a feed pump 27 is located in the pipe 43, said pump being coupled to an electric motor 26 the switch 25 of which is controlled by a float disposed in a chamber communicating with the boiler. As shown, the pipe 40 opens into the upper part of the boiler and terminates in a circumferentiallyextending spray pipe 47, or a simple spray head, and the boiler has a steam outlet 28 leading to a heating system &c. from which condensate may be returned to the tank 29 through a pipe 30. The arrangement is such that when the steam demand falls the pressure increases, and this pressure is communicated by a pipe 35 to the valve 34 which moves to the position shown in Fig. 4 to mate the pipes 42, 46 so that water from the boiler is returned to the tank 29. An increase in steam demand, however, causes the pressure to decrease and the valve 34 to move to mate the pipes 42, 43, whereupon water will be pumped back into the boiler until the switch 25 is opened. The pipe 43 is connected to the Lank 29 through a relief valve 44, and the tank 29 is provided with a make-up water pipe 31, controlled by a float valve 32, and a vent 33.