Gas separator for a combustion chamber

A gas separation assembly for a gas turbine engine combustion chamber is disclosed having spaced apart partition walls which extend through an end of the combustion chamber so as to define an oxidizer chamber which communicates with a source of oxidizer. Downstream ends of the spaced apart partition walls within the combustion chamber are interconnected to a plurality of generally "V" shaped spacers oriented such that the apex of the "V" configuration faces toward the end of the combustion chamber. Downstream edges of the partition walls are notched, also in a "V" shaped configuration such that the notches extend between opposite legs of the spacers. The spacers are circumferentially spaced apart so as to define passageways which communicate with the oxidizer chamber to enable oxidizer to pass through the gas separation assembly into the combustion chamber. The notches in the downstream edges of the partition walls form a series of generally radially extending flues to facilitate heat transfer between the combustion zones by convection. The design also eliminates the hot spots of the known prior art separation assemblies.

BACKGROUND OF THE INVENTION 
The present invention relates to a gas separator assembly for a gas turbine 
engine combustion chamber, more particularly such an assembly which 
improves the heat exchange between combustion zones within the combustion 
chamber and eliminates high temperature concentrations on the assembly. 
Combustion chambers having a generally annular configuration extending 
about an axis of symmetry and defined by opposite sidewalls and an end 
wall are known in the art. It is also known to utilize two distinct arrays 
of fuel injector nozzles to inject fuel into two combustion zones within 
the combustion chamber. Typically, one of the arrays of the fuel injectors 
are utilized to supply fuel to the combustion chamber in a first 
operational mode of the gas turbine engine, such as under low power 
conditions, while the other array of fuel injector nozzles inject fuel 
into the combustion chamber under second operational conditions, such as 
full power. It is also known to have oxidizer intake passageways through 
the end of the combustion chamber in order to supply oxidizer to support 
the combustion of the fuel/oxidizer mixture, as well as to provide a gas 
separating assembly attached to the end of the combustion chamber and 
inserted between the respective fuel injector arrays. A typical example of 
such structure can be found in U.K. patent application 2 010 408. 
The design of the gas separator assembly is critical to the combustion 
chamber design in order to provide the proper heat exchange between the 
combustion zones in the chamber. The known gas separation assemblies, 
however, do not provide the optimum heat exchange due to the presence of 
"dead" zones wherein such heat exchange is nonexistent or inadequate. In 
particular, the known separation assemblies do not provide any heat 
exchange by convection. Also, the known gas separation assemblies comprise 
large projections inside the combustion chamber and tend to form hot spots 
thereon which interfere with the combustion process. 
SUMMARY OF THE INVENTION 
A gas separation assembly for a gas turbine engine combustion chamber is 
disclosed having spaced apart partition walls which extend through an end 
of the combustion chamber so as to define an oxidizer chamber which 
communicates with a source of oxidizer. Downstream ends of the spaced 
apart partition walls within the combustion chamber are interconnected to 
a plurality of generally "V" shaped spacers oriented such that the apex of 
the "V" configuration faces toward the end of the combustion chamber. 
Downstream edges of the partition walls are notched, also in a "V" shaped 
configuration such that the notches extend between opposite legs of the 
spacers. The spacers are circumferentially spaced apart so as to define 
passageways which communicate with the oxidizer chamber to enable oxidizer 
to pass through the gas separation assembly into the combustion chamber. 
The notches in the downstream edges of the partition walls form a series of 
generally radially extending flues to facilitate heat transfer between the 
combustion zones by convection. The design also eliminates the hot spots 
of the known prior art separation assemblies. 
The partition walls of the gas separation assembly extend through the end 
of the combustion chamber such that the separation assembly is located 
generally between the two combustion zones. Fuel injectors for injecting 
fuel into the respective combustion zones are located on either side of 
the gas separation assembly. 
In an alternative embodiment, additional, generally triangular spacers are 
located circumferentially between adjacent first spacers and are oriented 
such that a base of the triangle faces generally towards the end of the 
combustion chamber. In this particular embodiment, the oxidizer 
passageways are defined between sides of adjacent first and second spacers 
and are oriented such that the oxidizer passes into the combustion chamber 
obliquely to a longitudinal axis of the combustion chamber.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The combustion chamber, as illustrated in FIG. 1, comprises an inner wall 1 
having a generally annular configuration about axis of symmetry 2, an 
outer annular wall 3, also concentric about axis of symmetry 2, the inner 
and outer annular walls being interconnected at an upstream end by end 
wall 4. Together, the walls 1, 3 and 4 define a combustion chamber 5. The 
combustion chamber may be enclosed by an inner casing 6 and an outer 
casing 7, both symmetrical about axis 2 and which define between them a 
space 8 which is fed a pressurized oxidizer from a source (not shown) in 
the direction of arrow G. As is well known in the art, the oxidizer may be 
provided from a compressor stage of the gas turbine engine. 
Fuel injection nozzles 9 and 10 are connected to fuel supply manifold 11 
and extend through the end wall 4 of the combustion chamber so that they 
may inject fuel into the combustion zones 17 and 18, respectively. In 
order to provide the proper fuel/air mixture to support combustion within 
the combustion zones, inner and outer walls 1 and 3 define primary 
oxidizer intake orifices 14 which communicate with the space 8 to enable 
oxidizer to pass into the combustion zones of the combustion chamber. 
Walls 1 and 3 also define dilution oxidizer intake orifices 15, which also 
communicate with the oxidizer space 8 and enable the combustion gases to 
be diluted, in known fashion. 
The gas separation assembly according to the present invention is 
illustrated at 16 and, as can be seen, extends through the end wall 4 and 
into the combustion chamber 5 generally between the combustion zones 17 
and 18. The gas separation assembly 16 extends into the combustion chamber 
5 approximately to the axial location of the axes 14a of the primary 
oxidizer intake orifices 14. The gas separation assembly 16 may be affixed 
to the end wall 4 by known means, such as welds 19. 
A first embodiment of the gas separation assembly according to the present 
invention is illustrated in FIGS. 2-4. As can be seen, the gas separation 
assembly 16 comprises first and second spaced apart partition walls 20 and 
21, each concentric about the axis of symmetry 2 and which extend 
generally parallel to upstream portions of the inner and outer walls 1 and 
3 of the combustion chamber. The spaced apart partition walls 20 and 21 
define therebetween an oxidizer chamber 22 and both are affixed to and 
extend through the end wall 4 of the combustion chamber. The oxidizer 
chamber 22 communicates with the oxidizer space 8 via chamber 23 such that 
oxidizer is supplied to the oxidizer chamber 22. 
A plurality of first spacers 24 extend between the first and second 
partition walls adjacent to their downstream end portions (those portions 
which extend furthermost into the combustion chamber) and are oriented 
substantially radially with respect to the axis of symmetry 2. As can be 
seen, the first spacers 24 have a generally "V"-shaped cross-sectional 
configuration and are oriented such that the apex 25 of the "V" shape 
faces upstream, towards the end wall 4 of the combustion chamber. Each 
spacer 24 comprises a pair of opposite legs 24a, 24b, having downstream 
edges 26 which are generally coplanar with the downstream edges 27, 28 of 
the partition walls 20 and 21, respectively. Adjacent downstream edges of 
adjacent sides of the first spacers are circumferentially separated by a 
distance D, which is greater than zero. 
The downstream edge portions of the partition walls 20 and 21 define a 
plurality of notches 29 which are also generally "V" shaped and which 
extend between the legs of each first spacer. The notches 29 and the 
spacer legs 24a, 24b form a plurality of flues 29a which are oriented 
generally radially with respect to the axis of symmetry 2. An oxidizer 
passageway 30 is defined between adjacent first spacers such that the 
passageways 30 allow oxidizer from the oxidizer chamber 22 to pass into 
the combustion chamber in the direction of arrows H, best illustrated in 
FIG. 3. As can be seen, in this embodiment, the oxidizer enters the 
combustion chamber generally parallel to the longitudinal axis A of the 
combustion chamber. 
The embodiment illustrated in FIGS. 5 and 6 includes all of the structure 
of the embodiment illustrated in FIGS. 2 through 4 plus the addition of a 
plurality of second spacers 31 having a generally triangular configuration 
and located between adjacent first spacers 24. The second spacers 31 
extend between the first and second partition walls 20 and 21 adjacent 
their downstream end portions and, as can be seen, have a generally 
triangular-shaped cross-sectional configuration. The spacers 31 may be 
fixedly attached to the first and second partition walls by any known 
means, such as by welding. Again, the second spacers 31 extend generally 
radially with respect to the axis of symmetry 2 and are oriented such that 
a base of the triangular cross-section faces upstream, towards the end 
wall 4 of the combustion chamber. Two sides 31a, 31b, of the second 
spacers 31 are adjacent to two of the first spacers 24 so as to define 
therebetween oxidizer passageways which communicate with the oxidizer 
space 22. In this embodiment, the oxidizer passageways permit oxidizer to 
pass from the oxidizer chamber 22 into the combustion chamber 5 in the 
directions of arrows J. The directions of arrows J are oblique to the axis 
A of the combustion chamber. 
A downstream edge 32 of each of the second spacers 31 is located adjacent 
to the downstream edges 27 and 28 of the partition walls 20 and 21, 
respectively. This embodiment, as in the first embodiment, defines a 
plurality of generally radial flues 29 to facilitate heat exchange between 
the combustion zones by convection. 
Although FIG. 1 illustrates only two fuel injection nozzles, 9 and 10, it 
is to be understood that the fuel injection nozzles are arranged in 
annular arrays which arrays are generally concentric about the axis of 
symmetry 2. 
The plurality of flues 29 defined by the gas separation assembly according 
go the present invention allows gas circulation, in particular by 
convection, between the combustion zones 17 and 18, thus avoiding the 
presence of "dead" zones in which no circulation takes place (particularly 
adjacent the downstream edges 27 and 28) and, as a result, the invention 
eliminates the dangers caused by hot points forming on the known gas 
separation assemblies. Also, the intake of the primary oxidizer directly 
through the end wall 4 of the combustion chamber in the directions of 
arrows H or J, allows the combustion chamber structure to be axially 
shortened even when a portion of the primary oxidizer is supplied from 
orifices formed in the sidewalls of the combustion chamber. 
The foregoing description is provided for illustrative purposes only and 
should not be construed as in any way limiting this invention, the scope 
of which is defined solely by the appended claims.