Patent GB-606208-A (GB)
Title: Improvements in and relating to tubular hot-water boilers or steam generators
IPC: F24H1/43
Filed: 1946-01-09
Abstract: 606,208. Hot-water and steam boilers; feedwater regulators. WEBB, H. W. B. Jan, 9, 1946, No. 845. [Class 123(ii)] In a tubular hot-water or steam boiler, a part PHC, Fig. 7, of the tubing is arranged in the form of a continous helical baffle or baffles each of which latter is composed of a plurality of convolutions disposed in side-by-side relationship and in contact with one another so as to form, with a surrounding casing 7 and an inner wall FC of closely-wound helical tubing, a helical flue or flues 12a for the passage of combustion gases from a furnace chamber 3, access to the baffle or baffles being had upon removal of said casing Feed-water is supplied to the lower end of the tubing PHC through which it circulates up and down to the lower end of the coil F.C., hot water or steam being withdrawn from the upper end of the latter. A sheet metal fuel hopper 2 and flue 26 are provided. In a modification, Fig. 2, the tubes are located within a casing 7 between an upper fuel hopper 2 and a lower furnace chamber 3 and consist of inner and outer closely-wound helical coils 1C, 2C with surrounding tubing PHC, the latter being arranged in the form of a helical baffle composed of a series of, say, six convolutions to provide a helical flue 12a for the combustion gases after their passage between the coils 1C, 2C. The flue 12a leads to a smoke box 24 and stack 26 provided with a damper 27, controlled automatically or by hand, and an upwardly-directed jet 28 supplied with steam from a coiled tube JC disposed below the coil 1C. Feed-water is supplied to the bottom of the outermost convolution of the tubing PHC by a pump, &c., preferably through an automatic control device including a water chamber 51a, Figs. 5 and 6, from whence it passes upwardly through the convolution, down the next two convolutions in parallel, and then up the three inner convolutions to the upper ends of the coils 1C, 2C down which the generated superheated steam flows to a chamber 51b, associated with the chamber 51a, and outlet pipe 52. The automatic feed control includes also a pipe 31 which extends through the chambers 51a, 51b and is charged with water, &c., being closed at one end by a plug 32 and connected at the other end to the bottom of a valve casing 33 below a flexible closure or diaphragm 34. The upper end of the casing 33 is also closed by a diaphragm 37, and the two diaphragms are mounted on an assembly which comprises a rod 38, flanged sleeve 39 and clamping nut 40, and is subjected to the pressure of an adjustable spring 41. The casing is further provided with a feedwater inlet, having a valve 43 adapted to be actuated by the sleeve 39 through a lever 42, and an outlet 46, and an extension of the rod 38 is preferably coupled to the stack damper 27. The arrangement is such that expansion of water in the pipe 31, due to high temperatures in the chambers 51a, 51b, will force the diaphragm assembly upwardly to open the valve 43 so that feed-water will be supplied to the boiler if the feedwater pressure is greater than that in the latter; if not, then the temperatures in the said chambers will increase and further upward movement of the diaphragm assembly will be effected, resulting in a closing movement of the damper 27 followed by a reduction in pressure in the boiler and the control casing 33. As the feedwater flows through the chamber 51a, however, it will cool the leg 31a of the pipe 31 and the latter will operate to permit descent of the diaphragm assembly with consequent opening of the damper 27 and closing of the valve 43, whereupon the temperature and pressure in the boiler will again rise to reopen said valve. A third construction of boiler is also described.