GB1135411A - Improvements in or relating to fuel burners - Google Patents

Abstract

1,135,411. Fuel burners. BABCOCK & WILCOX Ltd. 14 March, 1966 [12 March, 1965], No. 10633/65. Heading F4T. A burner with an atomizing nozzle 21 has flow passages defined by the interior of an inner tube assembly 2 and the annular space between the tube assembly 2 and an outer tube 3, the tube assembly 2 being formed by rigid inlet and outlet tubes 7 and 6 connected by a stainless steel bellows 9 by means of connecting pieces 11 and 10 sealed to the bellows by bands 13 and 12. An extension 15 of connecting piece 11 limits the compression of the bellows by abutting connecting piece 10. The tube assembly 2 is located within tube 3 by a collar 5 and by a spacer 18, the latter being welded to tube 6, slidable in tube 3 and provided with eight fluid passages 19. The nozzle 21 is screwed at 38, 39 to an inner tube assembly extension 22 and a seal provided by an aluminium washer 41. A sleeve 24 is screwed at 42, 43 to an outer tube extension 23 and clamps the nozzle between an inwardly directed flange of the sleeve 24 and the extension 23, sealing being provided by an aluminium washer 45. The wall thickness of outer tube extension 23 is increased at 29 to locate inner tube extension 22 and is provided with eleven fluid passages 32. A feather key 34 secured in a slot 35 in inner tube extension 22 and slidable in a slot in wall section 29 of outer tube extension 23 prevents relative rotation between the inner tube assembly 2 and outer tube 3. A collar 31 on inner tube extension 22 limits the extent to which the latter may slide in the outer tube extension, thus preventing the bellows from being over-stretched. The fluids flowing through the burner are conveyed to twelve divergent outlet passages 48 via conical recess 49 and convergent passages 50 formed in the nozzle. A fluid inlet 20 is welded to outer tube 3 either upstream or downstream of the bellows 9. In a modification, Fig. 3 (not shown), the bellows 9 is welded to a connection piece 56 which extends into a bush 51 replacing the collar 5 of the first embodiment, and is welded at its other end to a connection piece 55 formed integrally with a slidable spacer 54 which locates the inner tube assembly. Fluid inlet 20 is located downstream of the bellows and the annular space between the inner tube assembly and the outer tube in the region of the bellows is partially filled by a sleeve 58. A feather key 59 is welded in a slot in outer tube 3 and extends into a slot 61 in spacer 54. An abutment 62 on the feather key 59 prevents over-stretching of the bellows by limiting the movement of spacer 54. An air space is formed between outlet tube 6 and a further tube 64 which surrounds it. Three radial fins 66 on the tube 64 locate it in the outer tube 3, and fins 75 on the outer tube locate it in a furnace wall entry tube 67. In this modification the increased thickness wall portion 29 is omitted.