Patent GB-827963-A (GB)
Title: Improvements relating to fuel burners
IPC: F23D99/00
Filed: 1955-12-28
Abstract: 827,963. Oil burners; blow lamps. HUNTER, R. H. Dec. 28, 1955 [Dec. 31, 1954], No. 37153/55. Classes 75(1) and 75(4) An oil fuel burner, particularly a blow lamp burner, has at a place upstream of the nozzle, a thermostat arranged in response to the temperature of the pre-heated fuel, automatically to alter the ratio of the heat absorbed by the fuel during preheating of the latter by the flame to the total heat of the flame so as to regulate the partial vaporization of the fuel on its way to the nozzle in maintaining the temperature of the discharged fuel within predetermined temperature limits, so that resins, gums and other solids are carried by the non-vaporized portion of the liquid fuel to the burner and burned with the rest of the fuel. To this end the fuel is passed through a tortuous passage leading to the burner and is provided in an element disposed to be heated by the flame some of the heat from which may be directed to the tortuous passage by heat reflectors or directors, the conduits leading to this passage being in heat exchange relationship with a bimetallic element which is arranged when heated to move the element away from the flame. Additional means for manually so moving the element for adjustment purposes may be provided. As shown in a blow lamp burner, fuel from the reservoir 1, Fig. 1, passes under air pressure to a chamber, where for starting purposes only, it is mixed with air, thence through a conduit 60 through a bellows tube 82, Fig. 7, containing filling material 96, e.g. of steel wool, to force the fuel to flow around the helical passage formed by the bellows tube 82, through the conduit 84, Fig. 1, to the tortuous path in the form of a helical coil of tubing 80 located immediately in front of the opening 78 in the flame tube 11, through the conduit 85 to a second bellows-like tube 95, Fig. 5, containing within it an elongated bi-metallic element constructed of four bimetallic strips 91-94 shaped with arcuate sides to fill the central portion of the interior of the bellows tube 83 so that some of the fuel flows axially along the top and bottom surfaces of the element quite slowly and enables the unit to act as a sensitive quick-acting thermostat, the fuel then passing out of the bellows tube 83 through the conduit 61, Figs. 1 and 5, to the burner nozzle 64. As the temperature of the fuel rises the bimetallic element 91- 94 will deflect away from the flame as shown by the chain lines in Fig. 1 to move the coil 80 away from the flame until a position of equilibrium is reached when the heat supplied to the coil from the flame is sufficient to supply the losses of heat from the heater unit and the element 91- 94 remains constantly deflected and this equilibrium position of the coil 80 can be adjusted by mechanism 102 comprising a collar 103, Fig. 7, positioned' between a step 104 and a flame 105 and threaded on to a screwed stud 109 held in the bottom of the block 7, the tubes 82, 83 being held on either side of the collar 103 so as to be moved up or down by rotation of the handle 110 on which the items 103, 104 and 105 are formed. Reflectors 81, Fig. 1, on the coil 80 direct some of the heat from the flame on to the coil 80. Both tubes 82, 83 are surrounded by heat insulating sleeves 98, 97. To initiate operation of the lamp air is fed to the mixing chamber under control of a conical valve operated by a handle 51, Fig. 1. to mix with fuel oil fed under pressure from the reservoir 1 under the control of a conical valve operated by a handle 17 to provide an ignitable mixture feed to the nozzle, the flame from which heats the mixture in the coil 80 to partly vaporize the fuel whereupon the air feed can be cut off, the partly vaporized fuel alone then flowing to the nozzle and ignition is maintained. Protection for the lamp heater unit is provided by a shroud 115 secured to the front of the flame tube with clearances below the lowest position of the heater unit and above the flame tube and a hole 122 in front for the passage of the flame. The shroud has a flange 119 on either side of the rear part and overlapping flaps 124 welded together at the front below the hole 122. A hole 126 in the bottom and the arcuate openings 127, 128 allow cooling air into the interior of the shroud. Specification 812,921 is referred to.