Patent GB-430625-A (GB)
Title: Improvements in or relating to liquid fuel burners for use in heating plants
IPC: F23K5/00
Filed: 1934-09-29
Abstract: 430,625. Thermally - actuated valves. CASTIAUX, R., 106, Cours Victor-Hugo, Bordeaux, France. Sept. 29, 1934, No. 27923. [Class 135] [See also Group XI] The burner heating a boiler 1 for central heating &c., is supplied with fuel oil by allowing water to pass from the town mains past a pressureregulating valve 5 and a safety device 6 to the bottom of the fuel tank 3 the quantity of fuel supplied being regulated by a device 7 responsive to the temperature at some part of the boiler and the quantity of air being regulated by a valve 45 operated by a device 8 responsive to the fuel pressure. The fuel-regulating device 7 comprises a casing 91 fitted at one end with a tube 85 projecting into the water space of the boiler and containing an expansible liquid acting on a bellows 88. The bellows 88 carries a rod 89 operating through an adjustable push-piece 90 a valve rod 92 controlling the fuel flowing through a bellows 97 from a pipe 99 connected to the tank 3 to a pipe 101 leading to the burner. Normally the parts are in the positions shown in Fig. 8 with the apertured bottom of the bellows 97 abutting against the perforated end of a rod 100. If the water temperature rises excessively the valve 92 is moved to throttle the aperture 96 and the diminished pressure on the outside of the bellows causes a sudden closure. On the water temperature falling the valve 92 is withdrawn from the aperture 96 the movement of the bellows 97 being limited by a partition 93 and the consequent rise in the external pressure on the bellows causes the parts to resume their initial position. A bellows 95 connecting the valve 92 to the partition 93 prevents the escape of fuel from the bellows chamber 102. The burner may be maintained alight when the aperture 96 is closed by allowing a small amount of fuel to be delivered to the burner through an adjustable byepass 103. The safety device 6 which stops the admission of water to the tank 3 in the event of accidental extinction of the flame or obstruction in the stack comprises a valve box 45, Fig. 3, provided with a water inlet 46 and outlet 47, communicating respectively with two chambers 48, 49 separated by a valve seating 50 which may be closed by either of two surfaces 51, 52 on a valve rod 53 carried by the wall 54 of a bellows 55 forming the chamber 48. A vessel 74 arranged in the boiler fire box and a vessel 75 arranged in the air inlet 11 to the burner casing 2 contain a volatile expansible liquid and are connected to a bellows 67 carried by a socket 69 secured to the valve box 45. The bellows 67 carries a rod 71 projecting through a partition 84 in the socket 69 into engagement with the rod 53. A cam 77 freely mounted on the rod 71 is provided on one face with a helical projection 82 engaging a boss 83 on the partition 84 and on the other face with inclines 80 engaging inclines 81 on the wall 54. At starting the cam is turned till its handle 78 points nearly vertically upwards to operate the rod 53 to allow water to flow to the tank 3 and supply fuel to the burner. On ignition being effected the expansion of the liquid in the vessel 74 displaces the rod 53 to the right and the cam 77 is returned by the weight of the handle to its initial horizontal position. If subsequently the burner is extinguished the vessel 74 cools, the consequent contraction of the bellows 67 allowing the water pressure to expand the bellows 55 to cause the valve surface 51 to engage the seating 50 and prevent water from passing to the tank 3. A valve 62 in the chamber 49 is simultaneously withdrawn from engagement with a valve 59 and allows any pressure in the tank 3 to be relieved by the water escaping through a drain pipe 58. If the stack becomes obstructed the burning gases flow back to the air inlet 11 and by heating the vessel 75 cause the bellows 67 to be extended to such an extent that the valve surface 52 engages the seating 50 and prevents water from passing to the tank 3. The valve 62 is also moved to the right and opens the valve 59 against the resistance of a spring 60 to put the chamber 49 in communication with the drain pipe 58 and the cam 77 turns under the weight of the handle till the handle hangs vertically downwards so that on the extinction of the flame the fuel and water supplies will not be reestablished.