US2748567A

US2748567A - Gas turbine combustion chamber with telescoping casing and liner sections

Info

Publication number: US2748567A
Application number: US121105A
Authority: US
Inventors: Floyd G Dougherty
Original assignee: Motors Liquidation Co
Current assignee: Motors Liquidation Co
Priority date: 1949-10-13
Filing date: 1949-10-13
Publication date: 1956-06-05
Anticipated expiration: 1973-06-05

Description

DOU GH ERTY June 5, 1956 F, G, 2,748,567

GAS TUREINE coMBUsToN CHAMBERS WITH TELEscoPING CASING AND LINEE SECTIONS 2 Sheets-Sheet l Filed Oct. l5, 1949 s@ NNN, .T \e\ .Q KANN. f f mzknk ok 954000, mlv l, l xm@ W nu MN' k n .l N\ ammmmm mm N i@ www TN i@ M E 1 uw w1 Q f NQ \N\\\ \\..\.n mwN, E EN w "1T E n@ EN. NNN

Bnwcntor FLOYD G. DOUGHERTY June 5, 1956 F. G. DOUGHERTY 2,748,567

GAS TUEEINE coMEUsTloN cHAp/.EEES WITH TEEESCOPING CASING AND LINEE SECTIONS Filed oct. 15, 1949 2 sheets-shewL 2 Snucntor F LOYD G. DOUGHERTY United States Patent O GAS TURBINE COMBUSTION CHAMBER WITH 'TELESCOPING CASING AND LINER SECTIONS Floyd G. Dougherty, Indianapolis, Ind., assigner to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application October 13, 1949, Serial No. 121,105

8 Claims. (Cl. 6039.32)

This invention relates to impulse or jet engine construction and more particularly to specific combustion chamber or burner construction therefor so that the same may be easily serviced and parts replaced. lt is, of course, common knowledge that jet engines operate at extremely high temperatures which reduce the life of various parts to a relatively short period. Special alloys and metals for withstanding heat are used whenever feasible but even then it frequently becomes necessary to replace parts which have been deteriorated by the heat beyond further utility. One of the regions subjected toA the highest temperatures is, of course, the combustion chamber or burner unit itself, where the combustion of the fuel takes place, and it is particularly with the burner construction that the present invention deals.

Jet engines are commonly built with a number of burner units mounted in circular relation around a central shaft upon which is mounted a turbine at one end to drive the shaft and an impeller on the opposite end to compress the air for the burners. Each one of the burners is a complete combustion unit in itself, which feeds a common output chamber for the engine. Into the burner there are introduced a flow of fuel and at the same time a suicient amount of air to properly burn the fuel introduced. Inasmuch as this is one of the points in the jet engine at which extremely high temperatures are developed, the burner is apt to deteriorate rapidly, due to said intense heat. In order to provide longerlife for the burner units, liners have been mounted within the burner inside which the actual combustion takes place, and the liners, therefore, are subjected to the maximum heat, and after a period of operation can be replaced. The extreme temperatures to which the burners are subjected, however, cause rapid corrosion and warpage of the parts which in turn cause ditiiculty in removal and rebuilding.

It is, therefore, an object of my invention to provide lining means for a burner which may be simply and easily installed and removed.

It is a further object of my invention to provide lining means for a burner which is sectional and can be tele- 2,748,567 Patented June 5, 1956 Figure 4 is a sectional view taken on line 4 4 of Figure l in the direction of the arrows.I

Figure 5 shows a sectional View of two sections of the liner in telescoped relation.

Figure 6 is a vertical section through the rear portion of the partially disassembled burner showing in dotted lines the movement of the rear section for removal.

Figure 7 is a sectional view taken on line 7-7 of Figure 6 in the direction of the arrows.

Referring now more specifically to Figure 1, there isI shown therein one complete burner unit identified generally at 2 which, as mentioned before, is only one of a plurality of units mounted around a central shaft to form a complete jet engine. The burner per se is formed ofa central outer shell 4 having a telescopic similar circu lar member 6 which fits within the left-hand end and cart move with respect to the main outer cylinder 4 for purposes of taking up the expansion and contraction of the-y unit due to heat changes. A bellows element 8 is mounted outside both units and in juxtaposition to the cylinder 6 and has one end connected at 10 to the mounting means for the cylinder 6 and the other end rigidly connected as at 12 to the left-hand end of the cylindrical housing 4. Thus, as the temperature is raised and lowered, the two cylindrical parts 4 and 6 may move with respect to each other but stillV maintain a substantially closed cylindrical housing.

The mounting means for the cylinder 6 is a ring member 14 which has a notched face surface 16 fitting into a mating notched member 13 carried by a tapered front assembly 20 rigidly secured to a main frame. When the two ring members 14 and 13 are placed in juxtaposition, an outer clamping and restraining band 22 is placed around the assembly and tightly clamped thereto by tightening means not shown. This secures the nose assembly 20 to the main cylindrical housing, The nose section 26 also carries a fuel jet 23 which is mounted on the end ofv an inwardly extending member 24, the latter terminating in a coupling 26 to the fuel line. Mounted inside the nose section is a substantially conical liner section 28, the fuel tube 24 extending through an opening 30 in said liner 2S to reach the center of the enclosure. A bafe 32' is mounted in the outer end of the section 28 to divert the incoming air.

Within the main body of the burner is a cylindrical liner 34 which isl connected to and is supported by the inner end of the section 2S, said connection being through a plurality of peripherally spaced cap screws 35. Section 34 extends'approximately half way back through the main combustion chamber and terminates within a second cylin-V drical lining shield 36, the two being of different diamscoped together to assist in the removal of the same from f the burner.

With these and other objects in view which will become apparent as the specication proceeds, my invention will be best understood by reference to the following specification and claims and the illustrations in the accompanying drawings, in which:

Figure 1 is a vertical longitudinal sectional view taken through a burner of my invention.

Figure 2 is an enlarged vertical sectional view showing a portion of the forward section of the burner including the expansion adjustment means for the engine and the burner.

Figure 3 is a sectional view taken on line 3--3 of Figure 1, in the direction of the arrows.

etersV andrcapable of assuming a telescopic relation, the

liner' 34 being of less diameter than liner 36. On the outerv surface at the left end of the liner 36 as `shownin Figures; 1 and 3 there are located Vspaced series of loop members.; 38 which are secured tofsaid outer surface of the member- 36 and extend out to engage the inner surface of the combustionV chamber 4. rThese members act as spacers tolocate the liner properly with respect to the member 4- and also to provide engageable means for the securing threaded means 40. Threaded members 40 are screw` a supporting ring 52 (similar to ring 14 at the front) which mates with a second supporting ring 54, the latter being carried directly by a transition cover plate 55 of irregular shape having a central hanged opening 59 therein in which said ring 54 is secured. There are a plurality of these transition plates which are secured to an annular spider frame 83 by bolts 57, said spider frame having a circular outside periphery in which a number of spaced teeth 81 are provided. Its inner periphery also is provided with a series of spaced teeth 82. The teeth S1 on the outer periphery engage splines 84 carried by the frame 56, and the inner periphery teeth 82 engage in like manner splines 86, also secured to a portion of the frame. This provides for longitudinal relative motion between the spider member and the main frame for accommodating thermal expansion and contraction of the engine and burner assemblies. Gaskets 55a are provided between the transition cover plates 55 and the spider frame 83. The two mating rings 52 and 54 are maintained in juxtaposition in exactly the same manner as the front pair through an outer ring clamp 58, which is pulled tightly around the same when assembled. The rear outer section 60 of the burner is secured to frame 83 by welding and is tapered upwardly on one surface 62, but the upper surface projects substantially horizontally to the rear to form an inside pocket 64 at the top, the purpose of which will later be described. This member terminates in a housing 66 directly connected to the end of burner section 60, which housing is a part of an annular chamber 68 into which all of the burners discharge. The rear section of the liner member is formed of a hollow tapered section 70, the forward end of which is circular and flared outwardly as at 72 to accommodate the rear portion of section 36 and which is mounted and spaced from the casing by loops 71. Section 70 then becomes of smaller dimension on one diameter and greater on the other as it proceeds to the rear until it becomes of what might be termed a slightly arced rectangular section as at 74 to extend within the member 66 and then slightly outwardly as at 80 to form a joint with the outer surface of a collar 76. At this point the section 70 is not only of reduced vertical section but is of considerable expanded horizontal section, the general outline being best shown in Figure 7, where the forward portion appears as a circle which tapers back to an arcuate section at the rear. This rear arcuate section, therefore, forms one portion of a complete annular discharge member, each of the burners providing a similar section and, acting as an assembly, form a complete burner discharge.

Air for the burner, therefore, enters at the front or lefthand portion of Figure l, some of which passes past the bale 32 into the nose section 28 sweeping around the fuel jet 23 to cause combustion of the fuel being fed in that section within sections 34 and 36. Additional air also passes through that area outside the nose section 28, but inside the housing sweeping along the outer surface of the liner 34 to cool the same and to prevent heat from radiating to the outer housing member 4 and then into any one of the series of openings 50 to join with the gases being burned within the chamber, and lastly discharged into the rear arcuate opening provided in member 76. Some of the air which sweeps along the outer surface of the liner 34 also enters the forward portion of the liner 36 inasmuch as the two are designed in telescopic relation and, therefore, the larger rear section 36 will have some air introduced at its forward end. It will be seen, therefore, that the air insulation between the liner and the housing 4 will help to prevent the outer housing from becoming too heated, and also will provide the proper air for combustion at a distance from the fuel injection.

If it is desired to remove and replace the lining sections after a certain predetermined operation, collar 22 is rst removed, which permits movement of cylindrical member 6 by physically pushing it to the right as shown in Fig. 2 and collapsing the bellows 8. This gives access to bolts and they may be removed around the periphery. The

juncture between the lining sections and the main burner casing is now completely open at this point. Liner 34 is now forced to the right to partially telescope within section 36, as shown in Figure 5. Due to both cylindrical member 6 and liner 34 being moved to the right space is now provided to move the assembly as soon as the right end is disconnected. Collar 58 is then removed thus allowing the burner assembly 2 to be physically shifted to the left until liner 36 is disengaged with liner 70. This permits the burner assembly to be removed on a radial line outward from the engine center line. Bolts 57 are now accessible and may be removed, which permits removal of the transition cover plates 55. The rearmost liner section 70 may then be pulled forward to free its inner end from the member 76 and tilted up as shown in the dash and dot lines of Fig. 6 after which it may be removed with ease. This will permit the replacement of the liner or other parts of the burner structure as desired without sacrificing the engine structural strength or requiring major engine disassembly. The assembly is conducted in exactly the reverse order to the disassembly.

l claim:

l. A gas turbine combustion apparatus comprising, in combination, outer and inner shells, each shell comprising lixed entrance and exit portions and a removable intermediate portion connecting the entrance and exit portions of the same shell, the inner shell being contained in the outer shell and the two intermediate portions terminating approximately in the same planes, each intermediate portion comprising two relatively slidable parts adapted to be telescoped together to shorten the intermediate portions for removal from the entrance and exit portions.

2. A gas turbine combustion apparatus comprising, in combination, outer and inner shells, each shell comprising fixed entrance and exit portions and a removable intermediate portion connecting the entrance and exit portions of the same shell, the inner shell being contained in the outer shell and the two intermediate portions terminating approximately in the same planes, each intermediate portion comprising two relatively slidable parts adapted to be telescoped together to shorten the intermediate portions for removal from the entrance and exit portions, and means within the outer shell exposed by telescoping the outer shell for securing one part of the intermediate portion of the inner shell to one ofthe other portions thereof.

3. A gas turbine combustion chamber comprising, in combination, an outer casing adapted for mounting at each end thereof on fixed mounts in an engine, the outer casing comprising two parts relatively slidable so that they may be telescoped together for removal from the mounts; a liner adapted for mounting at each end thereof on fixed supports in an engine and disposed within the outer casing, the liner comprising two parts relatively slidable so that they may be telescoped together for removal from the supports; and means for securing one of the liner parts to one of the supports located within the casing at a region made accessible by telescoping the casing while in place.

4. A gas turbine engine comprising, in combination, an outer combustion casing adapted for mounting at each end thereof on xed mounts in an engine, the outer casing comprising two parts relatively slidable so that they may be telescoped for removal from the mounts, a combustion liner adapted for mounting at each end there of on xed supports in an engine and disposed within the outer casing, the liner comprising two parts relatively slidable so that they may be telescoped for removal from the supports, a turbine nozzle, a transition casing connecting one end of the outer casing to the nozzle, a transition liner for conducting combustion products to the nozzle connecting the corresponding end of the liner to the nozzle and flaring circumferentially of the nozzle, the transition casing being bulged outwardly to provide for lateral displacement of the transition liner at right angles to the direction of flow therethrough for removal thereof.

5. A gas turbine engine comprising, in combination, a turbine nozzle, a combustion chamber, a support spaced from the nozzle and extendingr transversely of the chamber for supporting the combustion chamber, the support including diverging members extending beside the chamber, and a transition combustion section extending from the support to the nozzle for conducting combustion products to the nozzle, the transition section comprising outer and inner shells, the inner shell widening in the direction from the support to the nozzle, and the outer transition shell being bulged outwardly from the inner shell to permit displacement of the inner shell laterally with respect to the support in the direction of divergence of the members during removal or assembly thereof to clear the radially extending members of the support.

6. A gas turbine engine comprising, in combination, an annular turbine nozzle, a plurality of combustion chambers, a spider spaced from the nozzle for supporting the combustion chambers including members extending radially of the nozzle between the chambers, and a transition combustion section extending from the spider to the nozzle for conducting combustion products to the nozzle, the transition section comprising an outer shell and a plurality of inner shells, the inner shells diverging circumferentially of the nozzle from the spider to the nozzle, and the radially outer surface of the outer transition shell being bulged outwardly from the inner shells to permit radially outward displacement of the inner shells relative to the axis of the nozzle during removal or assembly thereof to clear the radially extending members of the spider.

7. A gas turbine combustion apparatus comprising, in combination, outer and inner shells, each shell comprising fixed entrance and exit portions and an intermediate portion connecting the entrance and exit portions of the same shell, the intermediate portions being longer than the distance between the entrance and exit portions of the outer shell, the inner shell being contained in the outer shell, each intermediate portion comprising two relatively slidable parts capable of being telescoped together to shorten the intermediate portions to a length less than said distance for removal from the entrance and exit portions.

8. A gas turbine combustion chamber comprising, in combination, outer and inner shells, the outer shell comprising fixed entrance and exit sections and a removable intermediate section connecting the entrance and exit sections, the inner shell being mounted within the outer shell and comprising an upstream portion and a downstream portion both supported from the outer shell and an intermediate portion connecting and supported by the upstream and downstream portions, the intermediate portion being connected to the outer shell only through the upstream and downstream portions, the intermediate portion being slidably connected to the other portions of the inner shell, and readily detachable means securing the intermediate portion to one of other portions and locating the intermediate portion with respect to the said other portion.

References Cited in the tile of this patent UNITED STATES PATENTS 2,268,464 Seippel Dec. 30, 1941 2,337,038 Fentress Dec. 21, 1943 2,432,359 Streid Dec. 9, 1947 2,445,114 Halford July 13, 1948 2,479,573 Howard Aug. 23, 1949 2,493,641 Putz lan. 3, 1950 2,547,619 Buckland Apr. 3, 1951 2,548,886 Howard Apr. 17, 1951 2,610,467 Miller Sept. 16, 1952 2,650,753 Howard et al. Sept. l, 1953 FOREIGN PATENTS 576,545 Great Britain Apr. 9, 1946 0 tion Week.