Patent GB-275824-A (GB)
Title: Improvements in and relating to method of obtaining work from a vapour motor
IPC: F01K7/14
Filed: 1926-10-25
Abstract: 275,824. Prosser, J. G. Oct. 25, 1926. Compound &c. engines.-The heat supplied by jackets, receivers, &c. to the steam or other fluid in its passage through the various stages of a fluidpressure engine is controlled by hand or automatically in accordance with the desired quality of the fluid passing away at exhaust. The principle of correlation between the initial heat and volume of the steam supplied, the heat imparted to the working fluid during its passage through the motor, the structural characteristics of the motor and its speed as described in Specification 17441/15 are embodied in the invention. In a quadruple-expansion engine, Figs. 3 and 8, the cylinders have jackets 25 also extending around the valve chests 19. The heads 23 are also jacketed. Pipes 28, 29, 30, Fig. 7, supply the steam to the cylinder jackets, heads, and the interior of the pistons, the spaces being drained by pipes 31 - - 34 which provide a circulation of steam. The piston tail rod is jacketed by the chamber 39. As the piston reciprocates, drainage from its interior is discharged by pipe 40, recess 41, pipe 42, into chamber 43. The steam enters the engine by a pipe 52 passing through a separator 67, past valve 53, and in its' course through receivers 54, 55, 62 between the cylinders. Each receiver 54, Fig. 4, is formed as a tubular superheater wherein the steam passing from cylinder to cylinder passes by pipes 59, 60 and the heating-steam through spaces 65 coaxial with pipes 59, 60 and pipes 58. Branch pipes 66 extend from pipe 61 to the spaces 65. A main 78 supplies heating-steam for each unit of the engine. Branches 79 extend from the main 78 to the cylinders and have branches leading to the jackets, heads, pistons, and receivers each controlled by a manually-operated valve. An automatic control is provided at one or more points, e.g. valves 85 are arranged in each branch 79 and are controlled by a thermostat 86 located in the exhaust. The valve 85 has a double-lift valve 88, Fig. 11, connected to a bellows 91 containing a fluid subjected to heat changes in a thermostat arranged in the exhaust. A weighted lever 93 is connected to the valve stem. A thermometer 97 and a pressure gauge 98 are located adjacent the thermostat which with the aid of tables enables the quality of the exhaust to be determined. Preferably the heating is so arranged that the steam leaves the highpressure cylinder in a superheated condition, and .enters the last stage in a superheated condition and leaves it in a saturated condition. The method of controlling the heating in the last two stages, Fig. 3, may be applied to all stages. The quality of the vapour at the end of any stage of expansion may be obtained by the use of thermometer and pressure gauges arranged in the valve .chest, Fig. 8. One or more thermostats may be arranged between any of the stages in the motor and control the jacketing in any or all the stages. An arrangement of a quadruple expansion engine is described wherein thermostats in the low pressure exhaust control the receivers and jackets of the third and fourth cylinders, and thermostats in the third cylinder exhaust similarly control the receiver and jacket of the second and third cylinders, and a thermostat in the second cylinder exhaust controls the receiver and jacket of the second cylinder. Similarly an arrangement is described wherein thermostats between the various stages control all the jackets of the preceding stages. Manual control valves are also provided in each case. The thermostaticallycontrolled valves mav be constructed to facilitate disconnection as shown in Fig. 14. The valve stem is provided with a socket 890 in which the bellows stem 891 slides and is secured thereto by a set screw 892. When unsecured the valve is held open by a weighted lever. Means for effecting the control when the exhaust is against a variable back-pressure are described. Thermostats are arranged in the engine exhaust near the cylinder and in the condenser for example. These independently control electric contacts which when there is a change in the difference of temperature between the exhaust and condenser affect a solenoid-actuated valve provided in the steammain which has also a hand-controlled bye-pass.