GB690632A - Improvements in or relating to combustion apparatus - Google Patents

Abstract

690,632. Generating combustion products under pressure. POWER JETS (RESEARCH & DEVELOPMENT), Ltd. July 25, 1951 [July 27. 1950]. No. 18835/50. Class 51(i) [Also in Group XI] Apparatus for burning liquid fuel droplets carried in a stream of gas, e.g. air, comprises a vaporizing duct 7 disposed within a combustion chamber 11 and a mixing duct 3 disposed within the vaporizing duct, the fuel-carrying stream entering one end of the mixing duct to flow therealong, reversing direction at the other end to pass along the vaporizing duct outside the mixing duct and then reversing again to pass along the combustion chamber outside the vaporizing duct. The vaporizing duct and the mixing duct are of substantially the same length and the outlet of the vaporizing duct is disposed around the inlet to the mixing duct. The cross-sectional area of the mixing duct increases from its open upstream end and the crosssectional area at all sections of the space 6 between the vaporizing duct and the mixing duct is less than the cross-sectional area of the outlet of the mixing duct and is less than the cross-sectional area of the entrance end 10 of the combustion chamber. The inlet end of the vaporizing duct has a curved wall 5 and the inlet end of the combustion chamber has a curved wall 9 joining the combustion chamber to the inlet end of the mixing duct, the curved walls 5, 9 effecting a smooth reversal of the gas flow. Swirl vanes 8 are mounted in the annular space.6. The apparatus is mounted concentrically in a main cylindrical duct 1 through which passes air at. high velocity, the mixing duct receiving part of the air stream and the combustion chamber discharging into the rest of the air stream flowing between the combustion chamber and the main duct. A swirl atomizing nozzle 4 mounted on the main duct directs a conical jet of fuel into the mixing duct. A sparking plug igniter 14 is mounted in the entrance end 10 of the combustion chamber. The apparatus serves as a pilot burner for a main burner 15 mounted downstream in the main duct 1 and comprising an annular fuel tube having at most three sets of nozzles 15a, b, c directing fuel across stream, upstream and downstream. The combustion apparatus may be of annular form having the same axial section as that shown in the Figure for use in a main duct of annular form. The apparatus may be used in a gas turbine power 'plant to supply combustion products to the turbine or it may be connected to the turbine exhaust as part of a jet pipe with reheating by after burning.