Improvements in and relating to Valves for Controlling the Supply of Motive-fluid to Prime Movers.

摘要

2699. British Thomson - Houston Co., and Samuelson, F. Feb. 6. Piston valves.-Relates to a valve through which a low-pressure turbine or other prime mover may be supplied with low-pressure steam, and through which, when the low-pressure source of supply becomes insufficient, high-pressure steam may be admitted and expanded down to the proper pressure before entering the engine. Intets a, b are provided for the low and high pressure supplies respectively, a suitable low-pressure source being the exhaust of a high-pressure turbine or reciprocating engine. Valves d, e, mounted on the same spindle A, control the admission to a conduit c supplying the low-pressure turbine. Ducts l in the piston heads e of the high-pressure valve connect the space L with the space K and serve to equalize the pressure on opposite ends. An hydraulic operating-cylinder f fitted with a piston and provided with any suitable fluid supply controlling-mechanism actuates the valve stem A. If the low-pressure supply from the inlet a and valve d is insufficient, and the speed falls, the stem A moves downwards, and the lower piston head e uncovers ports m which admit the highpressure steam at the desired reduced pressure to the main valve casing whence it passes through the valve d into the turbine with the low-pressure supply. The high-pressure valve is also used at starting-up when, with a self-contained plant, no power is available for the air and circulating pump motors until the turbine is running.