GB591407A - Apparatus for controlling draft, particularly in the smoke boxes of locomotives - Google Patents

Abstract

591,407. Regulating draught. McINTOSH, R. R. Oct. 11, 1944, No. 19583. Convention date, Sept. 21, 1943. [Class 51 (i)] [Also in Group XXIX] In a locomotive smoke box the suction pressure is controlled by regulating the pressure in the exhaust pipe from the cylinders of the locomotive to a prescribed upper level below that to which it would normally rise and by admitting a suction reducing gaseous fluid such as air in controlled amount to the smoke box when the suction pressure therein exceeds a predetermined level. As shown in Fig. 3, the exhaust from the engine cylinders enters an expansion chamber 24 leading to the blast pipe 15 provided with an auxiliary steam jet blower pipe at 18 and surrounded by chambers 6, 7 provided with gravity actuated valves 11 which open when the pressure in the expansion chamber reaches a predetermined level to pass steam directly to the atmosphere through pipes 22, Fig. 2. Steam may also pass from the expansion chamber 24 through a pipe 52 and open a gravity valve in a chamber 68 when the pressure reaches a predetermined level and escape to the atmosphere by way of the pipes 80, 22. Air is admitted to the smoke box through a transverse conduit 3, provided with end closure doors and a disc valve 33 which opens to admit air to the smoke box to reduce the suction pressure, the top of the valve being loaded by steam pressure led from the expansion chamber 24 to the top of the piston 41, Fig. 6, in the cylinder 38, the piston being connected by a rod 32 to the disc valve 33. Specifications 555,737, 575,412 and 578,378 are referred to.