GB234727A - Improvements relating to injectors for locomotive boilers - Google Patents

Abstract

234,727. Friedmann, A., [Firm of]. Dec. 17, 1924. Giffard injectors; regulating or controlling action.-An exhaust steam boiler feed injector device for locomotive boilers is provided with a valve with two seating surfaces which is lifted to allow the passage of an auxiliary supply of live steam of reduced pressure to the injector whenever the engine is stopped or there is not sufficient pressure in the valve chest to keep seated a non-return valve. The valve 6 which is thus lifted allows live steam that passes into the chamber 14 from the inlet pipe 10 through the passage 13 to pass under the valve seating 7 and down through the pipe 4 to a. nozzle surrounding the inner live steam nozzle 3. The valve 6 has an upper and larger seating 8 which, when the valve is lifted, shuts off the chamber 9<a> from the chamber 14, and the chamber 9<a> is cut off from the passage by a non-return valve 12 when the engine is running. The seatings 8, 12 are roughened to allow leakage of steam even when the valves 6, 12 are closed. The pipe 11 is connected with the valve chest, and when the engine is running under steam the valve 6 is seated at 7 so long as the pressure difference in the chambers 9, 14 does not exceed a certain value; the passage 4 is then closed and the injector is operated by live steam flowing through the passage 2 from the boiler and exhaust steam flowing through the pipe 1. When the throttle valve of the engine is closed and the exhaust steam supply ceases, the valve 6 is lifted to supply steam at reduced pressure through the pipe 4 to the injector.