Patent GB-234645-A (GB)
Title: Improvements in exhaust steam injectors
IPC: F04F5/46
Filed: 1924-06-11
Abstract: 234,645. Metcalfe, B. D., and Metcalfe, J. C., (Hard, M., and Buckbee, IV.). June 11, 1924. Giffard injectors; nozzles; overflow arrangements; regulating or controlling action. - In injectors using exhaust steam for supplying feed water to locomotive boilers, the valves that are located in the, supplementary live steam and auxiliary live steam conduits are arranged to be closed by the pressure of the steam flowing thereto, and fluid pressure means are provided to open the valves against the steam pressure. More particularly, the control devices are for use with an exhaust steam injector of the kind described in Specification 142,539, and as shown in Fig. 17. The installation is represented in Fig. 1 as applied to a steam locomotive, and comprises the injector A, exhaust steam valve-operating means B, water admission valve C, a duplex valve E containing the valves for controlling the supply of live steam to the injector, an automatic valve F, and a main valve D for controlling the operation of these members. The injector comprises main exhaust steam nozzle 25 that is longitudinally adjustable by adjustment of the shaft 41 from the cab, water cone 26, delivery nozzle 28, supplementary live steam nozzle 30, and a one-way check valve 43 in the delivery pipe 43a, the part 27a of the combining nozzle 27 being pivoted, as shown. The operating means B for the exhaust steam valve 33 comprises a rod 48, Figs. 17 and 20, connected to the valve and to a piston 47 mounted to slide in a cylinder 46. This piston is operable by pressure fluid that is admitted to the cylinder through a pipe 49, 50 when the main control is suitably operated. The water-admission valve casing C contains a valve 54 that is opened against the action of a spring 62 to supply water to the nozzle 26 when pressure fluid is admitted to the pipe 61. The duplex valve E, Fig. 14, contains valves 101, 102 which, when opened by steam pressure acting against pistons 111, 117, are opened to supply live steam admitted from the engine turret through the pipe 105 to the pipes 40<a>, 39a respectively leading to the member B. Steam is supplied to actuate the pistons 111, 117 through the pipes 115, 96 respectively connected with the members F, D. Each of these valves is provided with a stop 123 that is adjustable through a rod 128 with a handle 129 positioned near the driver. The main control D and the automatic control F are bolted together and communicate through passages 97, 98, Figs. 5 and 6. The control D is manually operated and contains a valve 79 rotatably mounted in a chamber 80. Live steam is admitted to the chamber 80 through a pipe 84 connected with the steam dome or turret of the locomotive, and the valve is provided with a number of ports which, according to the setting of the valve, establish communication with the members A, B, C, and E in the following manner :-In the first or off " position of the handle 73, live steam passes through the ports 81, 86 to the passage 91 and from thence through the pipe 50 to the cylinder 46. The piston 47 is then moved to close the valve 33 and prevent the entrance of exhaust steam through the pipe 32 to the injector. Further movement of the handle to the "water on " position, shown in Fig. 6, admits steam through the passage 92 of the valve to the pipe 61 to open the valve 54, admitting water to the nozzle 26 to start the injector. After the escape of water at the overflow pipe is noticed, the handle is moved to the " primary " position in which the opening 88 is uncovered to admit live steam to the pipe 96 connected to the cylinder 118 of the member E. The valve 102 is thereby opened and live steam from the pipe 105 passes through the pipe 39<a> to nozzle 30 of the injector. This raises the pressure in the injector and causes the flap 27<a> to open to discharge steam and water from the overflow pipe 45<a>. The driver then turns the handle into the " running " position, when the ports of the valve D are set to permit the escape of steam into the ashpan from the pipes 91, 50 49 and cylinder 46. By the release of pressure behind the piston-rod 48, the pressure of the exhaust steam raises the valve 33 and flows into the injector. The opening of the port 89 in the valve chamber 80 permits also live steam to flow through the pipe 94 to the passage 97 of the device F, when the valve 139 is raised for steam to pass to the pipe 115 and to the cylinder 112 of the control E. This opens the valve 101, admitting live steam from the pipe 105 to the pipe 40a connected with the exhaust steam chamber 31 and causing the jet to be established. When the throttle of the engine is opened, steam flows from the engine steam chest through the pipe 160 to depress the pistons 154. 139 to shut off the supply of live steam to the injector cases. In an " emergency" position of the handle, the injector is arranged to operate with a supply of live steam even when exhaust steam is available. Specification 223,983 is referred to.