GB801739A - Improvements in or relating to combustion equipment of gas-turbine engines - Google Patents

Abstract

801,739. Generating combustion products under pressure. ROLLS-ROYCE, Ltd. Oct. 20, 1955 [Nov. 12, 1954], No. 32925/54. Class 51 (1). Combustion equipment of a gas turbine engine comprises a number of flame tubes 16 disposed side-by-side in the annular space between air casings 11, 13, each flame tube being located axially of the air casing by means of a pin 19 engaging a strengthening ring 17 at the upstream end of the flame tube. The ring 17 makes spigot engagement with a cylindrical seat 18a of air inlet structure 18 mounted in the compressor discharge duct 10. The downstream end of each flame tube is slidingly engaged within an individual support ring 21 which is mounted by at least three locating pins projecting from adjacent structure into engagement with the support ring. The support ring 21 is formed with peripheral flanges 21a, 21b and with three bosses 21c which are bored radially of the support ring. A polygonal, angle-section ring member 30 is secured by set-screws 31 to the inner wall 12 of the nozzle box assembly and to each of its sides is attached by means of a strip 29 a bulkhead 23 in the form of a segment of an annulus having a central circular aperture. The edges of the bulkhead are flanged at 23e, the flange 23e on the radially inner side 23c being secured to the strip 29, and the circular aperture is flanged at 23d. Three pins 22 are mounted on the bulkhead 23 and engage the bores in the three bosses 21c, the radially inner fin 22 being riveted to a bracket 24 welded to the bulkhead, while the two outer pins 22 are formed with heads 22a which are secured by set screws 26 to bosses 25 welded in the bulkhead 23. The heads 22a are formed with lands 22b which engage in channels 25a formed in the bosses 25, the pins 22 being accurately located thereby. To remove a flame tube, the outer air casing 13 is first removed, and the locating peg 19 of the flame tube is then removed whereby the flame tube may be moved forwardly to disengage from the support ring 21. The two outer pins 22 are then removed thus permitting the support ring 21 to be withdrawn radially outwardly, and the flame tube may then be removed from the engine. In a second embodiment, the head 22a of each of the two outer pins 22 is formed of part-cylindrical section, the part-cylindrical portion engaging a correspondingly-shaped recess in the boss 25 ; upon removal of the set-screw 26, the head 22a may be turned to disengage from the recess in the boss and the pin 22 may then be removed radially. The upstream circular portion of a flame tube discharge nozzle 15 is secured within the circular flange 23d of the bulkhead 23.