GB686131A - Improvements in or relating to ignition arrangements for gas-turbine engines - Google Patents

Abstract

686.131. Igniting burner apparatus. ROLLS-ROYCE, Ltd. June 29, 1951 [June 29, 1950], No. 16331/50. Classes 75(i) and 75(iii) [Also in Group XII] In ignition apparatus for a gas turbine engine comprising a fuel injector 18, Fig. 1, discharging into a side chamber 16 opening into a main combustion chamber 11 and supplied with air for combustion and containing spark ignition electrodes 25, 27, a baffle 29 is disposed in the side chamber 16' in such a position as to prevent fuel flowing from the injector 18 directly across the spark gap. The electrode 25 is mounted in a ceramic insulator 26 and has its tip located substantially on the centre line of the chamber 16, whilst the earthed electrode 27 is welded to a bolt 28 passing through the wall 13 of the chamber 16 and' secured by a nut 28a, the gap between the electrodes being determined by the thickness of a washer 31 located between the head of the bolt 28 and a flat or conical surface provided on the wall 13. The unthreaded part of the shank of the bolt 28 and the hole in the wall 13 receiving the same are both so shaped as to locate the baffle 29 in its operative position. Air is supplied to the side chamber 16 through apertures 20 in a frusto-conical flange 13d at the upper end of the chamber 16 from an annular space 21 provided between the flange 13d and a cap 17, which space is fed with combustion air through passages 22 (not shown) in the wall 13 and communicating with the annular air space 12 between the combustion chamber 11 and the air casing 10. Additional air enters the chamber 16 from the space 12 through ports 24. In an alternative construction air is supplied to the annular space 21 through a pipe communicating with an apertured hollow lug disposed in the space 12 and locating the flame tube 11 within the casing 10. Specification 616,481 is referred to.