GB910505A - Burner apparatus for liquid fuel - Google Patents

Abstract

910,505. Rotary atomizing burners. RICARDO & CO. ENGINEERS (1927) Ltd. Nov. 16, 1960 [Nov. 23, 1959], No. 39707/59. Class 75 (1). A combustion apparatus comprises a tubular combustion chamber containing an annular wall 14 defining a primary combustion zone 18 inside the annular wall and a secondary combustion zone 11 between the annular wall and the wall 3 of the combustion chamber, a centrifugal rotary device 20 distributing fuel in the primary zone 18 and a rotary impeller rotated with the fuel device 20 and adapted to cause a portion of the combustion products to flow from the outlet end of the secondary zone 11 through the primary zone 18 to the inlet end of the secondary zone 11. The wall 3 of the combustion chamber is supported on a bed-plate 6 and the annular wall 14 is secured to tangential supports 15 secured to an annular baffle ring 8 connected to the lower end of a frusto-conical baffle 7 connected at its wider upper end to the wall 3. The centrifugal fuel device 20 comprises a rotatable pipe 24 extending upwardly from a fuel reservoir 26 in which a constant level is maintained by a float valve 22. The upper end of the fuel pipe is secured to a rotary casing 32 which extends downwardly to rest against a thrust race 56 supported on a plate 57. A hollow stanchion 34 supported by a spider 35 secured to the bed-plate 6 extends between the fuel pipe 24 and the casing 32 and a bearing 26 is provided between the upper end of the stanchion and the casing 32 and a further bearing 27 between the lower end of the stanchion and the fuel pipe 24. The fuel device 20 is rotated by an electric motor (not shown) driving a belt 37 acting on a pulley 38 on the outside of the casing 32. A vertical overflow pipe 40 extends through the fuel pipe 24 and is located therein by a helical member 50 secured to the outer surface of the overflow pipe 40, a small clearance being provided between the helical member and the inner surface of the fuel pipe. (The Provisional Specification states that the helical member 50 is secured to the fuel pipe 24.) The lower end of the overflow pipe is secured to a rigid link 42 projecting from a vertical control rod 43 pivoted to a lever 44 pivoted to a support 46 on the bed-plate 6. The plate 57 supporting the thrust race 56 of the fuel device 20 is connected by a member 58 to a second vertical control rod 60 pivoted to a lever 62 pivoted to a support 64 on the bed plate 6. The two pivoted levers 44, 62 are both connected to the same point of an operating lever 47 which is operated manually or thermostatically to raise or lower simultaneously the overflow pipe 40 and the fuel device 20 but the positions of the pivot points 45, 63 are chosen so that the vertical movement of the overflow pipe 40 is greater than that of the fuel device 20. The drawing shows the overflow pipe and the fuel device in their uppermost positions with the overflow pipe projecting a maximum distance into the fuel pipe to determine the maximum burning rate of the apparatus. The rotary impeller comprises two spaced discs 65, 66 connected to the casing 32 of the fuel device, the lower disc 66 having a flange 67 connected to the upper disc 65 so that an annular chamber 68 is formed. Blades 70 are secured to the upper surface of the upper disc 65 and blades 71 are secured to the lower surface of the lower disc 66, an annular plate 72 being secured to the lower blades 71 to define an annular air intake orifice 73. When the fuel device is in its highest position (as shown) the annular plate 72 is in line with an air inlet 2 at the base of the wall 3 and air is directed by the lower blades 71 into a passage formed between an annular deflector 13 and the wall 3, part of this air passing directly into the secondary zone 11 and part passing along the tapering annular space 10 between the wall 3 and the frustoconical baffle 7 and then through holes 12 in the baffle 7 to the secondary zone 11. The upper blades 70 are then located immediately below an inturned flange 16 of the annular wall 14 and consequently combustion gases are sucked downwardly out of the primary zone 18 into the inlet of the secondary zone 11. When the fuel device and impeller is lowered less fuel is burned and the impeller produces a reduced flow of combustion gas through the primary zone 18 and delivers less air to the combustion chamber. Cooling air enters the space 75 between the fuel pipe 24 and the casing 32 through holes 74 in the casing 32 and passes through holes 76 to the annular chamber 68 in the impeller and then outwardly through holes 77. The upper end of the fuel pipe 24 is covered by a perforated disc 78 but fuel is prevented from passing through the centre part of the disc 78 by a disc 80. Fuel bleeds through two openings 51 in the fuel pipe 24 to lubricate the two bearings 26, 27 and to pass through apertures 52 in the casing 32 to a chamber 39 in the pulley 38. This fuel then flows through openings 53 in the casing 32 to the thrust race 56. Specifications 764,596 and 910,504 are referred to.