Abstract: A transition member between a combustion section and a turbine section in a gas turbine engine. The transition member includes a casing inner wall and a plurality of spanning members. The spanning members extend radially outwardly from a radially outer surface of the casing inner wall. Each of the spanning members included a slot formed therein. Each slot is in communication with a first aperture formed in the radially inner surface of the casing inner wall and a plurality of second apertures formed in an aft side of the spanning member for effecting a passage of the cooling fluid from a first cooling fluid channel to an inner volume defined within the radially inner surface of the casing inner wall. The slots include a component in the radial direction and a component in the axial direction such that the first aperture is not radially aligned with the second apertures.

Abstract: An aft liner seal for a combustor for a gas turbine includes an inner shell having an inner and outer surface and central axis. The aft liner seal has an outer shell positioned over the inner shell that has an inner and outer surface and central axis coaxial with the inner shell. One of the outer surface of the inner shell or the inner surface of the outer shell has grooves angled relative to the central axis. The angled grooves and adjacent portions of the inner surface of the outer shell or the outer surface of the inner shell form cooling passages. The cooling air exits the cooling passages at an exit angle that is matched to a swirl angle of the combustor flow. Matching of the exit angle and the swirl angle minimizes shear of cooling air with respect to flow exiting the combustor liner.

Abstract: A gas turbine combustor including: a primary combustion chamber; a secondary combustion chamber downstream of the primary combustion chamber; a venturi having a venturi throat; a transition piece; a cap assembly attached to the primary combustion chamber, and an external turbulator member in operable communication with the cap assembly, wherein the primary combustion chamber includes a mixing hole arrangement for improving homogeneity of an air and fuel mixture in the combustor; the venturi throat is disposed within a predetermined distance upstream from the downstream end of the primary combustion chamber; the transition piece is composed of a duct body, with a plurality of dilution holes formed in the duct body; and the external turbulator member includes a step positioned at the second end of the centerbody, the step defining a radial distance about the second end of the centerbody.

Abstract: A combustor assembly includes a convergent segment followed by a divergent segment to advantageously improve combustion. The combustor assembly includes a first segment beginning at a forward end that transitions to a second segment past a transition segment in a direction along a combustor axis toward an aft end. The reduction in cross-sectional area within the first segment provides desirable fuel and air mixing properties. The convergent first segment in combination with the divergent second segment decreases residence time of fuel-air mixture within the combustor chamber that decreases production of undesirable emissions from the combustor assembly.

Abstract: An apparatus and method for protecting an inner radial surface of a housing of a turbomachine from corrosion. The method includes tapering the inner radial surface of the housing and a corresponding outer radial surface of a corrosion-resistant liner, and heating the housing to increase a diameter of the inner radial surface of the housing. The method also includes inserting the corrosion-resistant liner at least partially into the housing, and attaching the corrosion-resistant liner to the inner radial surface of the housing a solid-state bonding process.

Abstract: The invention relates to a wall element for a wall structure of a gas turbine engine combustor. The wall element has an inner, in use, hot surface, and an outer, in use, cooler surface. A plurality of projections is provided on the outer surface to facilitate heat transfer to a coolant flow. The wall element comprises a means to direct more coolant flow at a hot-spot on an adjacent tile than the remainder of the adjacent tile and thereby reducing the thermal gradient across the adjacent tile.

Abstract: A combustor assembly of a turbine engine is provided with a mechanical air regulation unit which selectively varies the amount of air being delivered into a combustion zone of the combustor based upon a pressure of a fuel being supplied to the combustor. A first type of air regulation unit would act to increase the amount of air entering the combustion zone when greater amounts of a high heat value fuel are being delivered to the fuel nozzles of the combustor. A second type of air regulation unit could act to decrease the amount of air entering the combustion zone when greater amounts of a low heat value fuel are being delivered into the combustor through fuel nozzles.

Abstract: A combustor includes a first combustion chamber, a pre-mixing primary fuel-nozzle assembly associated with the first combustion chamber, a second combustion chamber, and a secondary fuel-nozzle assembly associated with the second combustion chamber. The pre-mixing primary fuel-nozzle assembly includes a number of vanes configured to swirl airflow, each vane comprising a number of fuel injection holes configured to inject fuel into the airflow.

Abstract: A turbomachine includes a combustor assembly, a cap assembly attached to the combustor assembly, a centerbody within the cap assembly, a wall of the centerbody having a first end, a second end and an intermediate portion, and an external turbulator member in operable communication with the cap assembly. The external turbulator member is spaced from the wall to form a passage defined by a gap between the wall of the centerbody and the external turbulator. The external turbulator member includes a step positioned at the second end of the centerbody. The step defines a radial distance about the second end of the centerbody. The external turbulator member is formed having a step-to-gap ratio relative to the centerbody in a range of about 0.8 to about 1.2.

Abstract: A combustion system for a gas turbine engine is provided. The system includes a forward liner; an aft liner; a combustion chamber formed by the forward liner and the aft liner, the combustion chamber defining a lean combustion zone and a pilot combustion zone; a premixing zone coupled to the combustion chamber; a pilot fuel injector coupled to the combustion chamber and configured to deliver a first flow of fuel to the pilot combustion zone; and a slinger unit configured to deliver a second flow of fuel to the premixing zone such that the second flow of fuel is mixed with air in the premixing zone and directed into the lean combustion zone of the combustion chamber.

Abstract: A combustor for a turbine engine is provided. The combustor includes a first liner; a second liner positioned relative to the first liner to form a combustion chamber therebetween, the combustion chamber configured to receive a fuel-air mixture; an igniter positioned relative to the combustion chamber and configured to ignite the fuel-air mixture; a first group of air admission holes positioned in the first liner and forming a regular circumferential pattern around the first liner; and a second group of air admission holes positioned in the first liner at a first circumferential position corresponding to the igniter, the second group of air admission holes departing from the regular circumferential pattern.

Abstract: A transition duct for conveying hot combustion gas from a combustor to a turbine in a gas turbine engine. The transition duct includes a panel including a middle subpanel, an inner subpanel spaced from an inner side of the middle subpanel to form an inner plenum, and an outer subpanel spaced from an outer side of the middle subpanel to form an outer plenum. The outer subpanel includes a plurality of outer diffusion holes to meter cooling air into the outer plenum. The middle subpanel includes a plurality of effusion holes to allow cooling air to flow from the outer plenum to the inner plenum. The inner subpanel includes a plurality of film holes for passing a flow of cooling air from the inner plenum through the film holes into an axial gas flow path adjacent to the inner side of the inner subpanel.

Abstract: A transition duct (30) for a gas turbine engine (2) having improved cooling and reduced stress levels. The transition duct may be formed of two panels ((36, 38) joined together with welds (40) disposed remote from the bent corner regions (34) of the panels. Cooling channels (32) extending longitudinally in the direction of flow of the hot combustion gas carried by the duct are formed within each panel, including the corner regions. Because the entire annular width (W) of the transition duct is cooled, the gap (G) separating adjacent ducts around the inlet to the turbine (4) may be reduced when compared to prior art designs. Two-panel construction with welds remote from the corner regions is facilitated by maintaining the minimum bend radius in the corners (R2) and in the direction of flow (R4) to be greater than in prior art designs.

Abstract: A combustion chamber of a combustion system comprises a combustion space, a support structure, a heat shield, and at least one through-opening. The heat shield has at least two segments, and each segment has an edge region, a gap communicating with the combustion space being formed between edge regions of adjacent segments, and a retaining device. The adjacent segments include a support element disposed in a bottom region of the gap. The retaining device fixes the respective liner element on the support structure via the respective support element. The at least one through-opening communicates with the gap so as to enable a cooling gas to flow through the through-opening. The at least one through-opening is disposed in at least one of the respective edge region and the support element at the bottom region of the gap.

Abstract: A combustor liner with an input end and an output end includes an annular inner wall and an annular outer wall. At least one of the inner wall and outer wall is three-dimensionally contoured. The inner wall and the outer wall form a combustion chamber with the contours creating alternating expanding and constricting regions inside the chamber causing combustion gases to flow in the circumferential and axial directions.

Abstract: A gas turbine engine reverse-flow sheet metal combustor for an aero gas turbine engine has a louverless single-piece liner design which includes a plurality of effusion patches, containing multiple rows of effusion cooling holes, bounded by cooled effusionless bands to aid in repairability of the combustor. The cooling of the bands improves the durability of the combustor and provides a method of repair for the combustor.

Abstract: A transition duct support system for a transition duct that channels hot gases from a combustor exit to a gas turbine inlet of a turbine engine. The transition duct support system includes a transition support frame formed from a body positioned around a transition duct body at an outlet transition section. The transition support frame may include a first inner surface aligned with and positioned proximate to portion of the outlet transition section that is positioned at an oblique angle relative to the outer wall of the transition duct body to limit linear movement of the transition duct body in a first direction. The transition support frame may also include a second inner surface positioned at an oblique angle to limit linear movement of the transition duct body in a second direction opposite the first direction.

Abstract: A burner insert for a gas turbine combustion chamber is provided. The burner insert includes a burner insert wall including a cold side and a hot side, an edge delimiting the burner insert wall. The edge includes an edge bar extending at least partially circumferentially and projecting beyond the cold side. A burner opening for inserting a burner is formed in the burner insert wall.

Abstract: The combustion device (1) of a gas turbine includes burners (2) connected to a front plate (5) of a combustion chamber (3). The front plate (5) has, spaced apart from one another, a front sheet (8) and an impingement sheet (7) with aligned holes (11, 12) housing the burners (2). A piston ring (15) is provided between the front sheet (8) and impingement sheet (7) to seal the holes (11, 12). The axial length of the border of the hole (11, 12) of the front sheet (8) and/or impingement sheet (7) is longer than the thickness of the corresponding front sheet (8) and/or impingement sheet (7).

Abstract: An annular combustor for a gas turbine engine is provided that facilitates staged combustion in a lean direct ignition (LDI) mode over an extended range of operating fuel air ratios. A method is also provided for operating a gas turbine engine over a power demand range that facilitates staged combustion in a lean direct ignition (LDI) mode over an extended range of operating fuel air ratios.

Abstract: A combustor for a turbine engine includes a hot wall and a cold wall forming a dual walled liner and a liner cavity with the hot wall. The cold wall defines a plurality of impingement cooling holes configured to deliver an impingement cooling flow. A first downstream end terminates the hot wall and is configured to receive the impingement cooling flow from the plurality of impingement cooling holes, and a second downstream end terminates the cold wall and is longer in a generally downstream direction than the first downstream end. A combustion chamber is formed with the dual walled liner and the liner and faces an opposite side of the hot wall relative to the combustion chamber. The combustion chamber has a longitudinal axis and is configured to receive an air-fuel mixture in the generally downstream direction along the longitudinal axis.

Abstract: An annular combustor and a method for operating a gas turbine engine over a power demand range facilitate combustion in a lean direct ignition (LDI) mode over an extended range of operating fuel air ratios. The flow primary combustion air admitted into the primary combustion zone is varied in response to power demand from a maximum air flow rate of high power demand to a minimum flow air rate of low power demand, while the flow of dilution air into a quench zone downstream of the primary combustion zone is increased from a minimum air flow rate at high power demand to a maximum air flow rate at low power demand.

Abstract: A combustor for a gas turbine engine is provided that includes a support shell, a forward liner segment, an aft liner segment, and a seal member. The support shell has an interior surface, and exterior surface, and a plurality of impingement apertures disposed within the shell. The forward liner segment and aft liner segment are attached to the inner surface of the shell. The forward liner segment has an edge surface extending between a face surface and a back surface, and a seal shoulder. The aft liner segment has an edge surface extending between a face surface and a back surface, and a seal shoulder. The forward liner segment and the aft liner segment are separated from one another by a gap. The seal member is disposed within the gap. At least some of the plurality of impingement apertures disposed within the shell are aligned with the seal member and oriented to direct cooling air to impinge on the seal member.

Abstract: A combustor liner segment seal member is provided that includes a center section, a forward flange, and an aft flange. The center section includes a base surface, a gas path surface, a forward side surface, and an aft side surface. The forward flange extends outwardly from the forward side surface, and includes a width, a height, a shell side surface, and a liner side surface. The aft flange extends outwardly from the aft side surface, and includes a width, a height, a shell side surface, and a liner side surface.

Abstract: The present invention provides a gas turbine capable of reducing energy consumption while suppressing a so-called cat back phenomenon. The gas turbine includes a combustor-accommodating chamber casing for accommodating therein a combustor which burns fuel and air compressed by a compressor to generate combustion gas and which injects the combustion gas to a turbine. The gas turbine also includes a first air supply passage and a second air supply passage on an upper portion of the combustor-accommodating chamber casing in the vertical direction. The first air supply passage discharges air toward the compressor in the combustor-accommodating chamber casing. The second air supply passage discharges air in a direction different from that of the first air supply passage.

Abstract: A turbomachine including an annular combustion chamber, a sectorized turbine nozzle arranged at an outlet from the chamber, and a sealing mechanism interposed axially between the chamber and the nozzle, the sealing mechanism including an annular gasket that is axially resilient. The gasket includes a first axial bearing mechanism for bearing against a downstream end of the chamber and a downstream annular lip that is sectorized, each sector of the downstream lip being in alignment with a sector of the nozzle and including a second axial bearing mechanism for bearing against an upstream end of the nozzle sector.

Abstract: An air bypass band assembly includes a transition piece of a gas turbine, the transition piece having at least one opening therein to allow a flow of air to pass through the at least one opening. The air bypass band assembly also includes a band that is movable between at least two positions, a first one of the at least two positions being a closed position where the at least one opening is closed to prevent the flow of air from flowing through the at least one opening, a second one of the at least two positions being an open where the at least one opening is opened to allow the flow of air to flow through the at least one opening. The air bypass band assembly further includes a mechanism that moves the band between the at least two positions.

Abstract: A combustor liner assembly includes a liner assembly, including a hot dome, a hot wall, and an impingement shield. The liner assembly further includes a convector assembly. The combustor liner assembly further includes an impingement dome assembly, including a ring-shaped portion defining a plurality of apertures configured to receive a plurality of fuel injectors, and a face. The ring-shaped portion and the face define an annular passage, and the face defines a plurality of apertures and a plurality of orifices. The convector assembly and the impingement dome assembly are operably coupled to one another, and the plurality of orifices of the face are configured such that the hot dome is exposed to air flowing in the annular passage of the impingement dome assembly. The combustor liner assembly is configured to provide flow communication between the annular passage of the impingement dome assembly and the plurality of fuel injectors.

Abstract: An article, such as a bucket, a blade, a nozzle, a vane, a strut, a fuel nozzle, a combustion casing, and a transition piece, the article having a damping coating comprising approximately 8 wt % to approximately 15 wt % Y2O3 and approximately 19 wt % to approximately 28 wt % Ta2O5 with the balanced weight of ZrO2 is presented.

Abstract: A tunable transition piece aft-frame is disclosed for tuning the exit profile of combustion products as such products flow from a transition piece to a combustion product receiving apparatus. The aft-frame includes a generally rectilinear shaped body which has a laterally extending flange. Dilution holes are formed in the flange and are configured to allow dilution air to penetrate into the flow of the combustion products to shape the exit temperature profile of the combustion products.

Abstract: An annular turbomachine combustion chamber comprising an inner wall, an outer wall, and a chamber end wall disposed between said inner and outer walls in the upstream region of said chamber, the chamber end wall presenting a central portion and an outer assembly flange, and the outer wall presenting an upstream assembly flange, the chamber end wall and the outer wall being assembled together by their assembly flanges, in which the free edge of said outer assembly flange is curved inwards. In addition, the outer face of the outer assembly flange presents a shoulder.

Abstract: A combustion chamber which includes a chamber endwall which takes the form of a substantially frustoconical component including a succession of adjacent planar portions is disclosed. The invention can be applied to a combustion chamber of a turbine engine.

Abstract: A gas turbine engine has a combustor module including an annular combustor having a liner assembly that defines an annular combustion chamber having a length, L. The liner assembly includes a radially inner liner, a radially outer liner that circumscribes the inner liner, and a bulkhead, having a height, H1, which extends between the respective forward ends of the inner liner and the outer liner. The combustor has an exit height, H3, at the respective aft ends of the inner liner and the outer liner interior. The annular combustor has a ratio H1/H3 having a value less than or equal to 1.7. The annular combustor may also have a ration L/H3 having a value less than or equal to 6.0.

Abstract: A gas turbine engine assembly includes a combustor configured to combust an air-fuel mixture to produce combustion gases in a first direction; a transition liner coupled to the combustor and adapted to receive the combustion gases from the combustor and to redirect the combustion gases in a second direction; and a turbine coupled to the transition liner and adapted to receive the combustion gases from the transition liner. The transition liner has a plurality of effusion holes that include a first group that extend at least partially in a tangential direction.

Abstract: A liner is provided for an air flow passage of a gas turbine engine. The liner comprises an acoustic attenuation layer which forms an air-washed surface of the flow passage, and a heat exchanger layer which extends as a backing to the acoustic attenuation layer. The heat exchanger layer is configured to carry a heated fluid flow and to transport heat from the fluid flow to the acoustic attenuation layer from where the heat is transferred to air flowing through the air flow passage.

Abstract: A combustor is provided having one or more apertures adapted to asymmetrically introduce air adjacent the fuel nozzles to reduce smoke resulting from unburned hydrocarbons in a gas turbine engine combustion system by impeding escape of unburned hydrocarbons.

Abstract: A turbine includes a transition portion where a combustor section joins a transition piece. The combustor section includes a combustor liner having an aft end that joins a transition piece body of the transition piece. A reduced thickness portion at the aft end of the combustor liner is covered by a cover sleeve to form an air flow passage on the aft end of the combustor liner. Apertures in the forward portion of the cover sleeve allow cooling air to flow into air flow passage. A plurality of turbulators project radially outward from the reduced thickness portion of the combustor sleeve towards said cover sleeve. An arch shaped resilient seal structure is positioned between the cover sleeve and the transition piece body. Supports formed on the reduced thickness portion of the combustor liner bear against the inside of the cover sleeve to prevent the cover sleeve from deforming inward due to a force applied by the seal, thereby ensuring that the air flow passage remains open.

Abstract: A combustor for a gas turbine engine includes an inner liner and an outer liner circumscribing the inner liner and forming a combustion chamber therewith. The outer liner is a dual walled liner with a first wall and a second wall. A fuel igniter includes a tip portion configured to ignite an air and fuel mixture in the combustion chamber. An igniter support assembly positions the fuel igniter relative to the combustion chamber. The igniter support assembly defines a plurality of holes configured to direct cooling air toward the tip portion of the fuel igniter. The igniter support assembly includes first and second floating seals that are configured to accommodate radial and axial relative movements.

Abstract: A combustor for a turbine engine is provided. The combustor includes a first liner and a second liner forming a combustion chamber. The combustion chamber is configured to receive an air-fuel mixture for combustion therein and having a longitudinal axis that defines axial and radial directions. The first liner is a first dual walled liner having a first hot wall facing the combustion chamber and a first cold wall that forms a first liner cavity with the first hot wall, the first liner cavity having first and second ends. A first liner seal is configured to seal the second end of the first liner cavity and to accommodate relative movement of the first hot wall and first cold wall generally in the axial and radial directions.

Abstract: An arrangement for sealing an opening formed in a wall for receiving a member. The arrangement comprises a sealing member with a passage, and the sealing member is moveably mounted on the wall adjacent to the opening such that the sealing member passage is substantially co-axial with the opening in the wall. Biasing means for biasing the sealing member towards the wall are also provided.

Abstract: A thermal machine is provided, in particular a gas turbine, which includes an annular combustion chamber which is bounded on the outside by an outer shell and an inner shell. The outer shell and the inner shell are each split on a separating plane into an upper half and a lower half, which are mechanically interlocked by welding one to the other on the separating plane. Increased mechanical robustness and a longer life of the combustion chamber are achieved in that an additional mechanical interlock is provided on the separating planes in order to absorb tensile and shear forces acting on the separating planes.

Abstract: A fuel injector system for injecting fuel into a turbomachine combustion chamber, the system comprising first and second fuel injectors wherein the first injector (22) is positioned in the center of the injector system (20) so as to inject a first fuel spray (42), and wherein the second injector (28) surrounds the first injector in such a manner as to inject a second fuel spray (48) of generally annular shape around the first fuel spray. The injector system further comprises an air admission duct (22) with outlet orifices (62) opening out between the first and second injectors so as to create a separator air film (f1) between the respective combustion zones of the first and second fuel sprays.

Abstract: A turbomachine combustion chamber has primary and dilution air inlet orifices formed by die stamping to have edges that project into the inside of the combustion chamber, and stress relaxation and/or reduction means in the edges or in the vicinity of the edges of said orifices, said means comprising, for each orifice, one, two, or three slots formed in the edge or around a fraction of the edge of said orifice.

Abstract: It is known to assist cooling of a combustion chamber in a gas turbine by fixing an exo-skeleton tile structure to an inner annular combustion liner shell. To improve structural integrity of the exo-skeleton tile structure, each tile is formed with at least one rib extending circumferentially across the outer surface of the tile. An end of each rib projects beyond one edge of the tile, like tiles being linked at overlapping edges by the inter-engagement of a projecting rib of one tile with the rib of an adjacent tile. The inter-engaging ends of the ribs are relatively slideable circumferentially to allow thermal expansion and contraction of the exo-skeleton structure, but sockets are provided where the ribs engage so as to resist relative bending of the adjacent tiles about their linked edges and impart rigidity to the structure.

Abstract: The invention relates to a heat shield element for lining a combustion chamber wall, to a combustion chamber and to a gas turbine. The heat shield element comprises a hot side that can be exposed to a hot medium, a wall side opposite said hot side, and a peripheral side adjoining the hot side and the wall side and having a peripheral side surface. Relief slots are introduced into the material in an area of the heat shield element that is susceptible to material cracks induced by thermal stress, thereby limiting crack propagation.

Abstract: A combustion liner cap assembly includes a cylindrical sleeve with a cantilevered fuel nozzle mounted therewithin; and a plurality of support rods. Each support rod has a first end supported by the cylindrical sleeve and a second end configured to contact the cantilevered fuel nozzle. Each support rod is adjustable in effective length to provide an adjustable compression force against the cantilevered fuel nozzle. A method for adjusting a resonant frequency of a cantilevered fuel nozzle mounted in a cylindrical sleeve is provided. A plurality of support rods extend between the cylindrical sleeve and the cantilevered fuel nozzle. An associated gas turbine has at least some combustion and rotor tones of interest. The method includes adjusting an effective length of the support rods to adjust compressive forces exerted against the cantilevered fuel nozzle to increase a resonant frequency of the fuel nozzle to be greater than the combustion and rotor tones of interest.

Abstract: A combustor assembly for a turbine engine includes an aft open end that communicates gas flow to a turbine assembly. The combustor assembly includes a liner assembly that terminates at a first fixed vane. A portion of the liner assembly extends an axial distance into the first fixed vane portion. An inner surface of the liner assembly corresponds with inner surfaces of the fixed vane portion to provide a smooth transition from the inner surfaces of the combustor assembly to the turbine assembly.

Abstract: A transition duct used in a gas turbine engine to direct the hot gas flow from the combustor into the turbine section of the gas turbine engine. The transition duct includes a plurality of guide vane integral with the duct. The transition duct includes a circular shaped inlet end for connection to a can combustor and a rectangular and arched shaped outlet end for connection to a first stage turbine section. the guide vanes extend within the flow path between inner and outer projections each having a curved opening in the shape of the airfoil each airfoil includes inner and outer airfoil ends with retainer slots formed between the airfoil ends and the duct projections that form shear pin retainer slots. Shear pin retainers are secured within the slots to secure the guide vanes to the duct in a thermally uncoupled manner to reduce thermal stresses. The guide vanes can be made from a single crystal material for higher gas flow temperatures.

Abstract: Cooling is provided for a gas turbine combustion system that includes a first member, such as a liner, having exterior and interior surfaces that define a wall therebetween and a central area. A second member, such as a cap, is located adjacent that interior surface. A source of cooling gas is in fluid communication with the exterior surface of the first member. An open space, in which is located a hula seal, is located between the interior surface of the first member and the second member. At least one opening in the wall of the first member provides a passageway for the cooling gas from the exterior surface of the first member to the open space. The passageway has a directional axis along which the cooling gas flows and is discharged into the open space. The directional axis is substantially oriented in a direction other than a direction towards the central area of the first member.

Abstract: The present invention provides a gas turbine capable of reducing energy consumption while suppressing a so-called cat back phenomenon. The gas turbine includes a combustor-accommodating chamber casing for accommodating therein a combustor which burns fuel and air compressed by a compressor to generate combustion gas and which injects the combustion gas to a turbine. The gas turbine also includes a first air supply passage and a second air supply passage on an upper portion of the combustor-accommodating chamber casing in the vertical direction. The first air supply passage discharges air toward the compressor in the combustor-accommodating chamber casing. The second air supply passage discharges air in a direction different from that of the first air supply passage.