GB631204A - Improvements in or relating to a liquid fuel burner - Google Patents

Abstract

631,204. Liquid-fuel burners. BREAULT, D. C. March 31, 1947, No. 8684. [Class 75 (i)] [Also in Group XXIX] A liquid - fuel burner for use with a combustion chamber comprises an outer housing enclosing a rarefaction chamber having a liquid fuel entry and an entry disposed opposite said liquid fuel entry for delivering atdmizing gas or steam to said rarefaction chamber, and an exit passage disposed in the wall of said rarefaction chamber adjacent said gas or steam entry and communicating with an expansion chamber having exit orifices disposed in the wall thereof and constituting the nozzle of said burner, said exit passage being so disposed as to ensure that fluids entering therein from said rarefaction chamber pass through the stream of gas or steam incoming through said gas or steam entry. A liquid-fuel burner adapted to be mounted in an opening 12, Fig. 4, of a furnace wall 10, has a fuel supply inlet 42 through which the fuel passes into a chamber 80 and through apertures 82 into a correspondingly apertured hollow member 98 where it is impinged upon by oppositely directed air from apertures 88 supplied through an inlet 43. The mixture of fuel and air passes through a reduced passage 100 to an expansion chamber 106 and is projected through apertures 104, 96 into the combustion zone. The member 98 together with the member 102, secured thereto to form the chamber 104, are connected to a rod 44 the rotation of which provides a simultaneous adjustment of the flow of fuel and of both the primary and secondary air. A rod 56, Fig. 2, projecting radially from the rod 44 co-operates at its outer end with a slotted member 52 secured to a frame 50 slidable on a plate 36 and connected by a rod 48 to a baffle 46 controlling the flow of secondary air through the opening 12. The frame 50 is adjusted by a reversible electric motor 58 with a cam follower connected to the which rotates a cam plate 60 co-operating frame, the cam plate 60 being preferably shaped so as to provide a slow initial increase of the air and fuel flows and then an accelerated increase. Baffle rings 72 may be provided in the opening 12 for further controlling the direction of flow of the secondary air. The burner structure is carried by a pair of hinges on a plate 18 on the furnace wall, the said hinges incorporating valves so that when the structure is swung out the liquid fuel and gas supplies are cut off. The hinge 22 incorporating the valve controlling the flow of liquid fuel is shown in Fig. 5 and comprises a bearing 110 fixed to a supporting plate and rotatably mounting the main valve body 112 to which is fixed the rod 28 supporting the furnace door, so that when the burner assembly is swung out from the furnace the housing 112 rotates in the bearing 110. Liquid fuel is supplied through inlet pipe 180 leading into a conduit 176 in a fixed member 166, and through an aperture 158 in a conical valve member 156. For starting the burner the member 156 is set so that the liquid fuel may flow through the aperture 158 and a metering valve 122 into a chamber 114 in the body 112 and through a pipe 42 to the burner. During the warming up period fuel returns through a pipe 154, a passage 152, an aperture 160 in the member 156, and a pipe 182 to the supply tank. As soon as ignition takes place the handle 164 is turned to close the passage 152 whilst the aperture 160 is moved to the position occupied by the aperture 158 to maintain the fuel flow to the burner. When the furnace door is swung open the body 112 rotates relatively to the fixed member 156 to cut off the fuel flow through the apertures 158, 160. The metering valve 122 is pressed downwardly by a spring 118, and upwardly by a spring 132 which acts upon a piston 126 engaging the valve stem 124, the setting of the valve being adjusted by the rotation of a screw 140 which presses against a stud 138 screwed into the piston 126, a spring 144 tending to maintain the setting.