Abstract: A combustion system for a gas turbine engine provides a reaction limiting means for preventing the combustion process within the combustion chamber of the engine from proceeding towards completion by limiting the reaction rate or duration of the reaction process sufficiently such that a clean combustion gas is produced having substantially less carbon particles than for a combustor effective for essentially complete combustion. The invention also provides an efficient method of removing carbon deposits which do form by controlling the combustor shutdown technique in such a way as to cause the carbon to be oxidized. The preferred embodiment provides an aircraft emergency power unit having a high pressure air storage tank, an aviation fuel storage tank, and a combustor with a reaction limiting means which combusts pressurized air and aviation fuel in a fuel rich ratio to produce a motive combustion gas in a reaction limiting means.

Abstract: A combustion system for a gas turbine engine provides a reaction limiting means for preventing the combustion process within the combustion chamber of the engine from proceeding towards completion by limiting the reaction rate or duration of the reaction process sufficiently such that a clean combustion gas is produced having substantially less carbon particles than for a combustor effective for essentially complete combustion. The invention also provides an efficient method of removing carbon deposits which do form by controlling the combustor shutdown technique in such a way as to cause the carbon to be oxidized. The preferred embodiment provides an aircraft emergency power unit having a high pressure air storage tank, an aviation fuel storage tank, and a combustor with a reaction limiting means which combusts pressurized air and aviation fuel in a fuel rich ratio to produce a motive combustion gas in a reaction limiting means.