GB1179023A - Gas Combustion Apparatus - Google Patents

Abstract

1,179,023. Gas turbine and like combustion chambers. WINGAERSHEEK TURBINE CO. INC. March 6, 1967 [March 17, 1966], No.10414/67. Heading F1L. [Also in Division F4] A gas combustion apparatus has a vortex generator at the inlet to a combustion chamber to set up a swirl and an eddying wake in the combustible gaseous mixture entering the chamber, the vortex generator being arranged so that combustion of the gases immediately adjacent the wall of the combustion chamber is delayed until near the outlet of the chamber. The combustion apparatus in one form comprises, Fig.1 a cylindrical mixing chamber 3 to which air is supplied by a compressor 1 via a valve 5 and fuel gas via a duct 7 and valve 9. The air/fuel mixture passes from the chamber 3 through a flame-holder 11 into a combustion chamber 13 where it is ignited by a spark plug 15 energized from a spark generator 17, the combustion gases flowing, for example, to a turbine or furnace. The flame-holder 11 comprises a hub portion 21 carrying at least two helical swirl vanes 23, 25 which set up a vortex in the combustion chamber 13 so that the cooler, denser particles of the mixture are centrifuged outwards to tend to cool the chamber wall, combustion of the gases adjacent the wall not taking place until near the chamber outlet. The vanes 23, 25 may be hollow or solid and have blunt trailing edges, Fig. 5, which cause eddies in the mixture to improve combustion stability. A fuel nozzle may be mounted on the hub 21. The dimensions A and B are substantially equal. In a modification, Fig.7, the combustion chamber is of rectangular cross-section and is supplied with air/fuel gas mixture from a mixing chamber through two rectangular section inlet ducts defined respectively by curved walls 41, 45 and 43, 51. The curvature of the inlet ducts sets up a vortex in the combustion chamber and the upstream wall 39 induces an eddying wake adjacent thereto. A similar arrangement is illustrated in Figs.9, 10 (not shown). In a further modification, the flameholder comprises a set of passages defined by helically wound tubes with the spaces between the tubes blocked to provide stabilizing regions.