Figure 1-27.-Double-annular combustion chambers.
The spark igniter plugs of the annular
Figure 1-26 shows a cross section of the parts of
combustion chamber are the same basic type used in
the double-annular combustion section quite clearly.
the can combustion chambers. There are usually two
Also included in the figure is the flow of air from the
plugs mounted on the boss provided on each of the
axial-flow compressor discharge through the liner on
chamber housings. The plugs must be long enough to
the turbine section. Primary air and secondary air
protrude from the housing into the outer annulus of
are indicated by arrows.
the double-annular combustion chamber.
The rotor shaft housing, shown in figure 1-28,
provides the inner wall for the axial path of the air.
Can-Annular Type
This housing unit is attached to the rear face of the
inner ring of the diffuser section. The housing is
The can-annular type combustion chamber is a
supported in the rear by components of the turbine
development by Pratt and Whitney for use in
section, not shown in figure 1-28.
1-21
