US2575889A - Burner assembly for the combustion chambers of internal-combustion turbines - Google Patents

Description

1951 G. OULIANOFF BURNER ASSEMBLY FOR THE COMBUSTION CHAMBERS OF INTERNAL-COMBUSTION TURBINES 2 SHEETS-SHEET 1 Filed March 5. 1947 Nov. 20, 1951 G. OULIANOFF 2,575,389

BURNER ASSEMBLY FOR THE COMBUSTION CHAMBERS OF INTERNAL-COB/[BUSTIQN TURBINES 2 SHEETSSHEET 2 Filed March 3. 1947 .zga fnzz'nir Patented Nov. 20, 1951 BURNER ASSEMBLY FOR THE COMBUSTION CHALIBERS OF IN TERNAL-COMBUSTION TURBINES George Onlianoll', ltiminggn,

England, assignor to Derby, England, a British company Application March 3, 1947, Serial No. 732,075 In Great Britain March 26, 1946 4 Claims. (Cl. BIL-39.65)

This invention relates to burner assemblies for internal combustion turbines of the kind having a tubular combustion chamber with the burner jet mounted on the axis of the combustion chamber within its inlet end.

According to the present invention there is provided for use with a combustion chamber of an internal combustion turbine, a spiderlike burner structure comprising an annular rim by which the spider-like burner structure is located within the combustion chamber, a central hub, a plurality of spokes connecting the central hub with the annular rim to support the central hub from the rim, said central hub having an axial extension from the outlet face of the spider-like burner structure. there being an axial bore in said central hub extension communicating with a fuel supply duct in one at least of said spokes, a fuel filter element accommodated in said axial bore, a jet element carried by said extension and communicating with the axial bore to receive filtered fuel therefrom, a cylindrical shroud secured on the central hub to surround said extension and extending axially from the central hub to adjacent the downstream end of said extension in radially-spaced relation to said extension thereby to afford therebetween an annular air space, air duct means in said central hub to convey air from the inlet face of the spider-like burner structure to said annular air space, and outlet means from the downstream end of said annular air space to direct air flowing in said space inwardly over the downstream end of said extension towards said jet element.

By arranging that the air leaving said annular air space is directed over the downstream end of said central hub extension, the formation of carbon deposits on the hub extension is substantially reduced.

when the burner structure is to be employed with a combustion chamber of the class comprising a tubular outer casing and a flame tube located coaxially within the tubular outer casing, the inlet end of the flame tube may be arranged to be supported by the central hub by providing on the central hub a vane-like structure to engage with the inlet end of the flame tube.

A specific embodiment of the invention will now be described, by way of example, with reference to the accompanying drawings whereof:

Figure l is a longitudinal sectional view of a combustion chamber in accordance with this invention,

Figure 2 is a view in the direction of arrow 2 of Figure 1,

near Clithcroe. ill-Royce Limited,

Figure 3 is a fragmentary view of -a part of Figure 1 to an enlarged scale and showing the burner assembly in section, and

Figure 4 is a section on th line 4-4 of Figure 3.

The combustion chamber, as shown in Figure 1. comprises an elongated outer casing 5 having an air inlet 8 at one end and a flame tube I mounted coaxially within the casing 5. The inlet 5 to the combustion chamber communicates with a compressor of the internal combustion turbine in known manner. The discharge end of the combustion chamber is supported as hereinafter more fully described, from a nozzle box casing 8 which also serves to support the nozzle box 9 by which the combustion products are conveyed from the chamber to the turbine.

A burner assembly generally indicated by the reference numeral i0 is mounted in the inlet end of the casing 5. Fuel is supplied to this burner from which it emerges as an atomised spray directed towards the discharge end of the combustion chamber. The air entering theinlet 6 is divided into various streams, the primary air stream passing between vanes II to within the flame tube whilst the secondary air passes between the casing 5 and the flame tube and enters the latter through the holes 12. Tertiary air flowing between the casing and the flame tube enters the latter through openings ill.

The burner assembly l0 comprises a circular rim 2|, three spider arms or spokes 22 and a hub 23. The casing 5 at its inlet end is constituted as a casting 24 having a cylindrical recess 25 on its inner surface to receive the rim 2| of the burner assembly.

The rim is provided with three equi-spaced studs 26 which pass through the end wall of the casting 24--the latter being formed with bosses 21 at these points to accommodate the studs. Nuts 28 are screwed on to the studs so that the burner assembly is rigidly secured to the outer casing 5.

The spokes 22 are, as shown in Figure 4, of streamline form in cross-section. One of the spokes 22 (namely spoke 22a) is drilled lengthwise to form a passage 29 which communicates with a hole 30 formed in the associated stud 28. This stud is arranged for connection to the fuel supply pipe.

The hub 23 projects axially away from the inlet 6 and the projecting portion I4 is cylindrical and formed with an open ended axial bore of which the inner end communicates with the passages 29 of the spoke 22a. In this way fuel 3 supplied to the burner assembly through this spoke will pass to the bore 3|.

A cylindrical gauze filter 32 is mounted in the bore 3| with one end abuttingthe shoulder piece 33 and the other end abutting the jet 34. The gauze 32 is open internally to the bore 3! but is closed by the jet 34. The Jet has a radial flange 35 which is clamped against the hub 23 by a cap nut 36. -The portion of the jet 34 within the bore 3| is of smaller diameter than the bore and is formed with inlet holes 31 for the fuel.

The portion of the hub 23 containing the filter 32 and the jet 34 with cap nut 36 is of reduced diameter and is enclosed within a cylindrical shroud 38 screwed on to the hub. Spaced passages 39 extend through the hub from its inlet face to the annular air space within the shroud 38 so that air can flow through the annular space and out from said annular space through an outlet provided between an inwardly-directed frustoconical flange 38a and the front face of the cap nut 36 thereby to travel inwardly over the downstream face of the burner structure towards the jet 34 and to prevent formation of carbon on the jet 34.

The portion I4 projects into the inlet end of the flame tube 1 which carries the vanes il. The vanes which impart a swirling motion to the primary air carry an inner shroud 15 which fits on the cylindrical portion 14 of the burner assembly, being slid axially thereon. In this way the flame tube is supported on the burner.

The outlet end of the flame tube 1 is mounted in the outer casing 5 by means of a sheet metal band l6 which surrounds the outer surface of the flame tube and is secured thereto at one end. The other end of the band It is bent outwardly to be clear of the flame tube and is provided with a number of slots l1 so as to form resilient fingers which bear againstthe interior of a ring secured to the end of the outer casing 5. In this way the flame tube I is located radially at its outlet end in the outer casing with freedom for axial movement relatively thereto. This mounting also permits of the flame tube expanding radially at its outlet end within the outer casing.

A dowel pin I8 is screwed into a collar l9 which is secured to the outer casing 5 towards the front end of it. The pin extends across the space between the casing 5 and the flame tube 1 and fits as a spigot in a socket 20 secured to the flame tube 1. The dowel pin i8 restrains the flame tube from both axial and rotary movements relatively to the casing 5 but imposes no restraint on expansion of the flame tube either radially or axially to each side of the pin.

With other constructions of burners, for example, those having separate fuel supplies and separate fuel restrictions in the burner assembly (e. g. those known as Duplex" burners) one or more spokes 22 additional to spoke 22a may be drilled to provide for the additional supply. Likewise, where burners are of the type involving eithera by-pass fuel return, for example, in the case of spill control burners, or where bypass spill takes place past an orifice controlling element in the burner, it is convenient to convey such by-pass flow through a drilled spoke additional to spoke 22a. A further requirement for an additional spoke drilling may arise where the fuel atomisation is assisted by supply of air to the burner assembly.

I claim:

i.- in me com us n sq pm nt fo n in 1mm WM wi h m inlet ternal combustion turbine or the like of the class comprising a combustion chamber having an outer casing and a flame tube located coaxially within the outer casing, the combination with said outer casing and flame tube, of a spider-like burner structure comprising an annular rim to engage with the outer casing adjacent its inlet end to locate the burner structure in the outer casing, a central hub, a plurality of spokes connecting the central hub with the annular rim to support the central hub from the rim, said central hub having an axial extension from the outlet face of the spider-like burner structure, there being an axial :bore in said central hub extension communicating with a fuel supply duct in one at least of said spokes, a fuel filter element accommodated in said axial bore, a jet element carried by said extension and communicating with the axial bore to receive filtered fuel therefrom, a cylindrical shroud secured on the central hub to surround said extension and extending axially from the central hub to adjacent the downstream end of said extension in radially-spaced relation to said extension thereby to afford therebetween an annular air space, air duct means in said central hub to convey air from the inlet face of the spider-like burner structure to said annular air space, outlet means from the downstream end of said annular air space formed by a flange on said shroud which flange extends inwardly from the shroud partway over the downstream end of said central hub extension in spaced relationship thereto, thereby to direct air flowing in said annular air space inwardly over the downstream end of said central hub extension towards said jet element, and means supported on said shroud and connected with the inlet end of said flame tube to support the flame tube from the central hub of the spiderlike burner structure.

. 2. In combustion equipment for an internal combustion turbine or the like of the class comprising a combustion chamber having an outer casing and a flame tube located coaxially within the outer casing. the combination with said outer casing and flame tube, of a spider-like burner structure comprising an annular rim to engage withthe outer casing adjacent its inlet end to locate the burner structure in the outer casing, a central hub, a plurality of spokes connecting the central hub with the annular rim to support the central hub from the rim, said central hub having an axial extension from the outlet face of the spider-like burner structure, there being an axial bore in said central hub extension communicating with a fuel supply duct in one at least of said spokes, a fuel filter element accommodated in said axial bore, a jet element carried by said extension and communicating with the axial bore to receive filtered fuel therefrom, a cylindrical shroud secured on the central hub to surround said extension and extending axially from the central hub to adjacent the downstream end of said extension in radiallyspaced relation to said extension thereby to at ford therebetween an annular air space, air duct, means in said central hub to convey air from the inlet face of the spider-like burner structure to said annular air space, outlet means from the downstream end of said annular air space to direct air flowing in said space inwardly over the downstream end of said extension towards said jet element, and means supported on said shroud end of said flame tube to support the flame tube from the central hub of the spider-like burner structure.

3. The combination according to claim 2, wherein said means to support the inlet end of the flame tube from said shroud comprises a plurality of vane members extending outwardly from said shroud to be engaged at their outer end with the inlet of said flame tube.

4. For use with a combustion chamber of an internal combustion turbine or the like which combustion chamber is of the class comprising an outer tubular casing and a flame tube supported coaxially within said tubular outer casing, a spider-like burner structure comprising an annular rim by which the spider-like burner structure is located within the combustion chamber, a central hub, a plurality of spokes connecting the central hub with the annular rim to support the central hub from the rim, said central hub having an axial extension from the outlet face of the spider-like burner structure, there being an axial bore in said central hub extension communicating with a fuel supply duct in one at least of said spokes, a fuel filter element accommodated in said axial bore, a jet element carried by said extension and communicating with the axial bore to receive filtered fuel therefrom, a cylindrical shroud secured on the central hub to surround said extension and extending axially from the central hub to adjacent the downstream end of said extension in radially-spaced relation to said extension thereby to afford therebetween an annular air space, air duct means in said central hub to convey air from the inlet face of the spider-like burner structure to said annular air space, outlet means from the downstream end of said annular air space to direct air flowing in said space inwardly over the downstream end of said extension towards said jet element, and a vane structure carried on said shroud and arranged to engage with the inlet end of said flame tube to support it from said central hub.

GEORGE OULIANOFF.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Mock et al Aug. 1, 1950

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