GB615434A - Improvements in and relating to steam generators - Google Patents

Abstract

615,434. Forced-flow steam boilers; feed-water supply systems; thermostats. JOOSTEN, J. Oct. 18, 1945, No. 27339. Convention date, March 10, 1945. [A Specification was laid open to inspection under Sect. 91 of the Acts, Oct. 18, 1945] [Classes 64(ii) and 123(ii)] A steam boiler comprises a liquid fuel and primary air supply conduit 43 and also a concentric secondary air conduit 44 which open into a combustion chamber 4, defined by a dome 3, and are surrounded by concentric passages 45, 46, 47 which house steam-generating coils 48b, 48c and a pair of superheating coils 48a and are traversed in succession by the hot gases flowing from said chamber 4 to an outlet 65. The coils 48b, 48c are connected together at 50 and the outlet end of the coil 48b is coupled to the superheating coils 48a by a tube 52 in the form of a collar concentric with the conduits 43, 44 and having a diameter substantially greater than that of these coils, the coils 48a themselves being coupled by pipes 9 to a spherical steam receiving chamber 5 which is mounted in the base of the dome 3 and is provided with an outlet pipe 10 leading to an engine, &c. The passages 45, 46, 47 are defined by cylindrical plates 23, 24, 25 and a main casing 1, the said plates being secured to the casing by a hollow conical chamber 20 constituted by plates 14, 18, and the casing 1 is extended at 17 over the dome 3 to provide a chamber 19, the two chambers 19, 20, and also that formed by the plates 23, 25, having a common inlet 21 and an outlet 22 for cold and preheated feedwater respectively with the outlet 22 connected to the inlet of the initial steam-generating coil 48c. Liquid fuel from a pipe 59 is fed into the conduit 44 through an injector 56 which opens into a venturi tube 57 in this conduit, primary air is supplied to said conduit, preferably after passage through a heater 39 surrounding the boiler casing 1, through a flexible conduit 55, and secondary air to the conduit 44 through an inlet 61, initial ignition of the combustible mixture being effected by a sparking plug. The water, fuel and air supplies to the boiler, also the temperature of the superheated steam, are controlled by a thermostat 103, Fig. 4, which is fitted in the steam outlet pipe 10 and comprises a cylindrical casing 201 provided with steam inlet and outlet branches 202 and 203 respectively. Located within the casing 201 are a number of concentric tubes 212 having alternately a high and low coefficient of expansion and connected, one to another, at their ends by ferrules 214, 216. The outermost tube 209 is anchored to the bottom 205 of the casing, and the innermost one 218 is connected at its upper end to a rod 219 which projects through a stuffing-box 220 in the casing cover 204 and is itself connected to a pivoted lever 223, the latter actuating, through suitable mechanism, not shown, valves in the several supply pipes.