Patent GB-191517441-A (GB)
Title: Improvements in and relating to Method and Apparatus for Obtaining Work from Vapour.
Inventor: PROSSER JOSEPH GEORGE
IPC: F01B17/04
Filed: 1915-12-13
Abstract: 17,441. Prosser, J. G. Dec. 13. Working-fluid supply; cooling and heating parts.-Comprises means for admitting vapour to a motor having a stationary element and a movable element, and means for supplying to the vapour admitted to the motor (without reducing the quality of the vapour at any time) some or all of the heat required to secure a predetermined quality of vapour at a predetermined point in the passage of the vapour through the motor. The heat is supplied by varying one or more or all of the following elements:-the volume of vapour admitted, the quality of vapour admitted, the amount of heat supplied to the vapour, the structural characteristics of the motor affecting thermal conditions, the other thermal conditions such as the heat supplied in jackets &c., and the speed of the movable element. The principles upon which the invention is based are described, the basic principle being that of affecting and maintaining such a correlation between the enumerated elements as to secure the desired result. The maximum efficiency is secured by supplying only vapour of the highest quality, and heating the walls to an extent sufficient to cause the pressure acting on the piston to follow the saturation curve whenever, after cut-off, vapour has reached a saturated condition. The cumulative effect of cooling in the cylinder is prevented or controlled by superheating air, eliminating moisture from the admitted vapour. The material, shape, and finish of the walls are such as to secure the transmission of a maximum amount of heat from outside sources to the interior surfaces, and to transmit from the wall surfaces to the working vapour a maximum amount of heat, except to the working vapour at the exhaust surfaces where the converse is necessary. The temperature should be high, and the number of expansions as many, and the range of temperature as large, as possible. No cooling of the working vapour takes place except that due to work performance. The invention is illustrated by reference to a reciprocating engine shown diagrammetically. The supply steam passes through a pipe 50 into a separator 49 and thence into the steam-chest 6 through a flared pipe with a scroll at its upper end to catch moisture rising by capillary action. The steamchest is connected with the cylinder by ports 7, 8 controlled by oscillating valves 9, 10 the seats of which are elevated slightly above the bottom of the steam-chest, so that no moisture can drain from the chest into the cylinder. The cylinder and valve-chest are surrounded by jackets 23, 24, and steam is circulated through the piston in the manner indicated. The steam, after passing through the piston, may pass through the cylinder jacket, or steam at different temperatures may be supplied to the piston and cylinder jacket as desired. The surface of the exhaust valve 15, 16 exposed to the workdngvapour is reduced to a minimum area not greater than the exhaust port. The jacket space 23 is arranged partly to surround the exhaust passage way and valve, and the exterior of the cylinder is grooved at 25. The walls of the exhaust passage are finished as smooth as possible and provided with a non-conducting material. The ends of the cylinders and the interior and exterior surfaces 28, 27 of the piston are grooved, and the working faces of the piston are made of copper or brass.