GB219041A - Improvements in or relating to injectors - Google Patents

Abstract

219,041. Brooke, R. G. Feb. 19, 1923. Giffard injectors; overflow arrangements.-The water valve is opened in advance of the supply of steam by means of a valve through which steam passes solely to the injector, a portion of the steam passing to a piston or diaphragm operatively connected to the water valve. The steam valve y, operated by a lever 16, Fig. 3, comprises a hollow head 12, Fig. 7. sliding in a member 13 and provided with a lateral port 14, and an enlarged solid portion y<1> normally seating against the valve seat w. An annular chamber w<1> formed in the member 13 communicates, through a. pipe v, Figs. 1 and 7, with a chamber u in which slides a piston t in a spindle s on which is mounted the spring-closed water valve o, Fig. 1. On the steam valve y being first opened, steam passes through the annular chamber w<1> and pipe c to open the water valve, steam not being admitted to the chamber 13<1>, feeding the injector nozzle until after the left-hand end of the valve head, Fig. 7, has cleared the annular passage. When the valve is closed the port 14 provides a pressure leakage passage from the chamber u to the injector nozzle through the hollow valve 12. In the modified form shown in Fig. 8, the hollow portion 12 is loosely mounted on the valve spindle 48, so that on the first movement of the spindle to the right, such movement being controlled by the lever 16, steam is admitted only to the annular passage w<1> and pipe v, the portion 46 in this instance being drawn to the seat 49. Further movement of the spindle moves the portion 12 to admit steam as before to the injector nozzle. In modified forms the piston t may be replaced by a diaphragm subjected on one side to the steam pressure. In a further modification, Fig. 11, the first movement of the valve-spindle 54a in an upward direction unseats the valve 53 to admit steam to the tube 58 communicating with the water valve, subsequent movement admitting the steam to the nozzle 52 in the manner described in Specification 169,743. The steam and water valves may be used in an injector having the overflow arrangements described in Specification 219,045. The invention is applicable to live and exhaust-steam injectors and to exhaust-steam injectors having a supplementary live steam supply.