Patent GB-772271-A (GB)
Title: Fuel burner
IPC: F23C5/02
Filed: 1954-12-28
Abstract: 772,271. Liquid fuel burners. PEABODY. Ltd. Dec. 28, 1954 [Dec. 28, 1953], No. 37471/54. Class 75(1) A burner comprises either (1) an atomizer barrel 10 slidably supported within a tube 12, a reversible motor 100 arranged  to retract the barrel within the tube or to advance the barrel so that the tip 11 is beyond the tube for firing, first and second reducing gear stages connecting the motor and the barrel, a releasable clutch between the two gear stages and manual means operable through the second reducing stage to retract or advance the barrel when the clutch is released or (2) an atomizer barrel 10 disposed within a slidably mounted tube 12 with the barrel tip normally projecting beyond the tube, a rack 50 and pinion 51 for advancing and retracting the tube and atomizer barrel as a unit with respect to an opening in the wall of a combustion chamber, a control shaft 52 disposed across the burner and coupled to the pinion 51 by a releasable coupling operable to re-connect the pinion and shaft only when the pinion is in a'predetermined position with respect to the shaft. The motor 100 and reducing gear are housed in a housing 101 secured to a housing 92, Fig. 4, slidably mounted on the tube 12 and having an extension 88 to which the end of the atomizer barrel 10 is connected by a connector 85. A shaft 93 carried by the slidable housing 92 is driven by the motor and reducing gear and has a gear 94 meshing with a rack 95 secured to the top of the tube 12. The first reducing gear stage comprises a worm 104, Fig. 8, and a worm gear 105 on a vertical shaft 106 and the second reducing gear stage comprises a worm 110 and a worm. gear 112, the second worm 110 being attached to a sleeve 111 rotatable on a second vertical shaft 109 carrying a gear 108 meshing with a pinion 107 on the first shaft 106. A handwheel 115 is keyed to slide on the upper end of the sleeve 111 and in its upper position, engages a pin 118 on a disc 119 attached to the end of the vertical shaft 109 on which the sleeve is rotatable, thus coupling the sleeve to the shaft. The handwheel is retained in its upper position by a spring urged ball 117. To retract or advance the atomizer barrel manually the handwheel is depressed and rotated. The slidable housing 92 also carries a pair of limit switches 120, 121 which are actuated by cam surfaces 122, 123 at the ends of the rack 95. The motor 100 and a fuel supply valve 153 are controlled by the circuit shown in Fig. 6 which includes power supply lines 130, 140, a manual two way switch 132, the cam operated switches 120, 121, a relay coil 144 operating a switch 145 and a fuel switch 147. The cam operated switches 120, 121 are shown in the positions corresponding to the atomizer barrel being fully advanced and with the two way switch 131 as shown and the fuel switch 147 closed the relay coil 144 is energized to close switch 145 to open the fuel valve 153. Neither winding 125 or 126 of the motor is energized so that the atomizer barrel remains in the advanced position. If the two way switch 132 is changed over the relay coil 144 is de-energized to close the fuel valve 153 and the motor winding 126 is energized to retract the barrel. The initial movement of the barrel causes the cam operated switch 121 to open contact 142 and close contact 141 and when the barrel reaches the end of its travel the cam operated switch 120 opens to stop the motor. The tube 12 carries a diffuser 13 at its inner end and is slidably mounted on rollers 16 in a hub 17 carried by a front .plate 18 hingedly mounted on the front wall 19 of the furnace. The rack 50 is secured to the tube 12 and the pinion 51 engaging therewith is mounted on a sleeve 58, Fig. 3, which is slidable on the shaft 52 and is latched in forward and retracted positions by the engagement of a spring pressed ball 59 in two annular grooves 61, 62 on the shaft. In its forward position the sleeve is connected by a key 63 to the shaft 52. In its retracted position the sleeve disengages from the key but the pinion still remains engaged with the rack so that when the sleeve is again, advanced to engage the key the tube 12 and the shaft are in the same relative positions as before uncoupling. The shaft is mounted on bearings 53 on the front plate 18 and is coupled by members 54 to a master shaft 55 extending across the front wall 19 of the furnace to control the diffuser tubes of other burners. The master shaft 55 carries a pinion 65, Fig. 5, engaged with a'rack 66 attached to a bell crank lever 67 rocked by a spring urged piston 72 in a cylinder 73 supplied with a fluid under pressure through a metering valve 76 controlling the pressure of the fluid in the cylinder and operated by a diaphragm 78 connected to the fuel return line 49 from the burner. The arrangement is such that increased 'fuel pressure in the return line reduces the fluid pressure in the cylinder and the piston moves downwardly to retract the tube 12. The metering valve may be operated by the pressure in the fuel delivery line. 44, or by the rate of fuel supply or by the steam pressure in a boiler heated by the burner. The master control shaft 55 may be actuated by a reversible motor controlled by the return fuel pressure. The fuel supply to the burner is controlled automatically by a valve 36 actuated by a diaphragm 40 responsive to the steam pressure in the boiler. In the positions of. minimum and maximum burner loading the flame cone is tangential to the burner throat 15. The burner includes an air register 21 having adjustable doors 22 and a gas ring 24 disposed within the burner throat. U.S.A. Specifications 1,824,952 and 2,290,350 are referred to.