GB223983A - Improvements relating to exhaust steam injectors - Google Patents

Abstract

223,983. Metcalfe, R. D., and Metcalfe, J. C. July 31, 1923. Giffard injectors; regulating or controlling action.-Comprises the provision of a single operating lever for the remote control of steamoperated valves in the water and exhaust steam supply passages of a Giffard injector. The same lever also controls the flow of live steam at boiler pressure through the injector and, in one construction, also controls the flow of live steam throttled to atmospheric pressure. In another construction, however, the supply of throttled live. steam is controlled by an independently-operated throttle valve. A valve c, Fig. 8. in the water supply passage is held to its seat by a spring u and is opened by live steam pressure on the underside of piston w, the steam entering by a passages z. Figs. and 16. The exhaust steam valve b is held to its seat by live steam pressure, supplied through a passage m, acting on a piston k, Fig. 16, and is opened when the supply of live steam is cut off. Drain valves x, r, Figs. 8 and 16, are provided in the piston cylinders of the water and exhaust steam valves respectively. The valve r may he formed in the piston k, and in a modified construction the valve b may be closed by a spring and opened by live. steam pressure. The live steam and throttled live steam for the injector are supplied through tubes f, g, respectively. In the construction shown in Figs. 2 and 16, a separately operable throttle valve 25 is fitted in the tube g, but actuation of such throttle valve, in a modified construction, may be obtained from the common actuating handle a. The tubes f, z, m, communicate with the main steam supply passage h through a valve d and pilot e and ports 7, 9, Fig. 6, forming a hit-andmiss arrangement with a disc valve p, Figs. 3 and 7. The operating member 14, Fig. 3, of the valves d, e is secured to a crank 13 secured to a spindle 11 on which are mounted the disc valve p and the operating handle a. A ball valve 10 places the tubes z, n in communication with the atmosphere through orifice 8, recess 6 in the disc p, Figs. 6 and 7, a tube 3, Figs. 3 and 16, at the proper times during the cycle, which is deter. mined by the movement of the actuating handle a from the position shown in Fig. 2 to the position 24 through the successive stages 20 - - 23. Specifications 142,539 and 180,628 are referred to.