Patent GB-795020-A (GB)
Title: Improvements in or relating to fluid heating apparatus
IPC: G05D23/00
Filed: 1956-03-06
Abstract: 795,020. Liquid and gaseous fuel-fired boilers. CLAYTON MANUFACTURING CO. March 6, 1956 [June 23, 1955], No. 7045/56. Class 51 (1). [Also in Groups XIII and XXIX] The oil-fuel supply to the boiler shown is controlled, through suitable means, by the expansion and contraction of a tube ring R, Fig. 1, which is anchored to the boilure structure at one point by a spacer 46 such that it may freely move to actuate a rod 55 which directly operates a fuel by-pass valve 63. The boiler comprises a steel-lined combustion chamber 7 surmounted by a tubular system 3 arranged in " pancake " fashion, the system forming, with the helically arranged tube 4 surrounding the chamber 7, the boiler tube system. Metal sleeves 9, 10, surround the system 3, 4, and the boiler walls are completed by refractory 12, air spacing 14 and metal casing 13. Fuel is supplied to a burner nozzle 33 through a pipe 35 and a valve 35a from a fuel tank 100 by a pump P which is also connected to the tank through a pipe 107, the valve 63 and a pipe 112. Combustion air is blown into a box 23 and caused to emerge whirling into the chamber 7. Some air flows to the spacing 14 through holes 24 and annular space 22 to eventually be passed into the boiler gas outlet 29 through holes 30. An observation window and tube 37, 36 are provided. Two adjacent turns of the tube 4 welded together form the ring R which is bolted at one point to an annular channel iron member 49 surrounding the refractory 12 through the spacer 46 secured to the ring. Diametrically opposite the said point the rod 55 is secured to the ring such that it may slidably move outwards through the refractory 12, member 49, space 14 and casing 13 to actuate the valve 63. The valve casing, comprising associated parts 75, 77, 78, Fig. 4, is rigidly secured to the member 49 through an open-topped box 64, the latter allowing adjustability of the initial setting of the rod 55 through rotation of a threaded sleeve 116. The rod 55 is biased inwardly by a spring 92 such biasing closing, through a rod 85 and conical portion 94, the communicating passage between valve inlet and outlet chambers 95, 96. In such rod position no fuel oil is returned to the tank 100, the nozzle 33 accordingly receiving its maximum supply. On a diameter BB, Fig. 3, additional spacer connections 46a are provided, a horizontal slot 46d being formed in the member 49 for each spacer and a washer associated with a bolt 51a being not engageable with the member so that the latter is relatively free to move with respect to the spacers 46a and the ring R. On expansion of the ring R the rod 55 is moved outwardly and the valve 63 inwardly, the latter movement occurring due to the elongation of the member 49 along the diameter BB by the spacers 46a. Depending upon the degree of relative movement between rod 55 and valve 63 more or less fuel will be diverted back to the fuel tank. An optimum fuel oil pressure is needed in the pipe 35 to keep the spring-loaded valve 35a open. The spacers 46a may be eliminated. In such a construction the valve 63 would remain stationary, effecting thereby a less heat-sensitive fuel supply control. In a further construction greater control sensitivity is effected by using long spacers 46a to pre-elongate the member 49. In the construction shown in Fig. 7 the rod 55 actuates an electric switch 120 which controls a solenoid actuating the fuel supply valve 121. This construction may utilize either liquid or gaseous fuel.