US2777291A - Combustion chamber with removable flame tubes - Google Patents

Description

Jan. 15, 1957 R. F. DARLING 2,777,291

COMBUSTION CHAMBER WITH REMOVABLE FLAME TUBES Filed May l0, 1952 2 Sheets-Sheet l ATTORNEYS Jan. 15, 1957 R. F. DARLING COMBUSTION CHAMBER WITH REMOVABLE FLAME TUBES 2 Sheets-Sheet 2 Filed May 10, 1952 United States Patent O COMBUSTION CHAMBER WITH REMOVABLE FLAlVIE TUBES Robert Francis Darling, Monkseaton, England, assigner to The Parsons and Marine Engineering Turbine Research and Development Association, Wallsend, England Application May 10, 1952, Serial No. 287,211

Claims priority, application Great Britain .Iuue 12, 1951 This invention relates to combustion chambers particularly, though not exclusively, for gas turbines.

In designing the combustion system for a gas turbine one of the rst questions that has to be decided is whether to have a single large combustion chamber or a number of small ones working in parallel, each arrangment having its own disadvantages. In a single chamber the parts may be too heavy to be handled conveniently, and in addition, a fuel sprayer of large output gives coarser atomization than a smaller one Working at the same fuel supply pressure. This latter difculty can sometimes be overcome by using a cluster of small sprayers in a single combustion chamber, but such a cluster is not easy to install satisfactorily, and there is sometimes a tendency for the sprays to interfere with one another.

If, on the other hand, several small combustion charnbers are employed in parallel, it becomes diieult to maintain a uniform temperature at the turbine entry, as the quantities of air and/ or fuel supplied to the individual chambers may not be identical, and in particular, considerable labor and expense is involved in ensuring that the sprayers all give exactly the same fuel iiow at all pressures.

The object of the present invention is to provide a combustion chamber embodying a plurality of removable flame tubes and in which a substantially uniform temperature can be attained.

The present invention consists in a combustion chamber for a gas turbine or the like having features as set forth in the claims appended hereto.

Referring to the accompanying diagrammatic drawings:

Figure 1 is a vertical longitudinal sectional view of one convenient form of combustion chamber embodying the present invention.

Figure 2 is a sectional plan view of the arrangement shown in Figure 1.

Figure 3 is a cross sectional view on the line III- III of Figure 2.

Figure 4 is a cross-sectional view of a possible alternative form of that shown in Figures 1-3.

In carrying the invention into effect according to one convenient form illustrated in Figures 1-3 as applied to a combustion chamber for a gas turbine, a large circular outer casing a is furnished with two pairs of radial holes d in walls, a detachable domed cover c being fitted to each hole. Flame tubes e are inserted one through each of the holes d with their longitudinal axis at right angles to the longitudinal axis of the casing, and their inner ends register with holes in a perforated inner member within the chamber. Each cover cis fitted with a fuel sprayer k. The air is introduced at the inlet of the chambers and outlet j is the hot gas outlet.

The detachable covers c may be removed in order to insert or extract the ilame tubes e in relation to the hoies in the outer casing a and inner member s.

The air enters the outer casing of the combustion chamber through an opening Thereafter it can follow a number of alternative paths. Most of it distributes itself between the ilame tubes and passes through the various air ports therein to the combustion spaces contained within the llame tubes. From here the combustion gases issue into the common mixing zone h, and thence through the combustion chamber outlet. A portion of the air, however, may pass from the outer casing through the adjustable valve n direct into the mixing space h where it mixes with the combustion gases and passes with them to a combustion chamber outlet j. Opening of the adjustable valve n allows more air to pass through it and thereby reduces the amount of air passing through the llame tubes. In this way the operation of the valve n enables the air flow through the arne tubes and hence the air/ fuel ratio in the flame zone to be controlled.

By this means the gas issuing from any one llame tube outlet is caused to mix with gases from the other ame tubes and also with any air which may have been allowed to pass the damper n. This results in a substantially uniform temperature distribution at the outlet of the chamber, even when fuel is supplied to some of the flame tubes but not others.

I claim:

l. A combustion chamber comprising an outer cylindrical member, an inner member co-axial with the outer one, both inner and outer members being perforated in such a way that flame tubes can be inserted through the perforations in the outer member and lit into the perforations in the inner member, arne tubes tting into the said perforations in the inner member and extending so that the longitudinal axes of these tubes lie at right angles to the longitudinal axis of the outer member, removable apertured covers fitting the perforations in the outer member and sprayers inserted through the apertures in the said covers.

2. A combustion chamber as claimed in claim 1, the said inner member having also a further perforation providing for air flow from the space within the outer tube into the inner member, and comprising also an adjustable valve member in the last said perforation for regulating flow therethrough.

References Cited in the le of this patent UNITED STATES PATENTS 520,481 Davis May 29, 1894 1,380,997 Metcalfe June 7, 1921 1,568,479 Sownitza Jan. 5, 1926 2,119,580 Hardgrove June 7, 1938 2,140,785 Cone Dec. 20, 1938 2,332,866 Mller Oct. 26, 1943 2,430,344 Kemp Nov. 4, 1947 2,565,843 Dennison Aug. 28, 1951 2,604,797 Peregrine July 29, 1952 2,609,040 Aronson Sept. 2, 1952 2,654,219 Zaba Oct. 6, 1953 2,715,816 Thorn et al Aug. 23, 1955 FOREIGN PATENTS 449,129 Great Britain June 22, 1936

Images