Torch igniter for a combustor having U.V. flame detection

In a torch igniter for producing a torch flame for igniting a combustor flame in a gas turbine combustor operating at above atmospheric pressure and for detecting the existence of the torch flame and of the combustion flame in the ignited combustor by a single detector:

• a torch ignition chamber for containing a mixture of torch fuel and torch air;
• ignition means for igniting a mixture of torch fuel and torch air in the ignition chamber means;
• torch air supply means for supplying a stream of air to said ignition chamber means;
• exhaust means for exhausting the combustion products and torch flame from said ignition chamber means through the wall of a refractory insulated combustion chamber and into a combustion zone of the combustion chamber;
• and
• a single ultraviolet radiation detector means operatively associated with the torch igniter for detecting ultraviolet radiation emanating from the torch flame and the ignited combustion flame in the combustion chamber, whereby the existence of the torch and combustion flames are detectable by said single ultraviolet radiation detector means.

In a torch igniter for igniting a flame in the combustion chamber of a gas turbine combustor operating at above atmospheric pressure:

• a torch ignition chamber for containing a mixture of fuel and air;
• said ignition chamber including an exhaust port for exhausting flame and combustion products from said ignition chamber into the combustion chamber of the combustor for igniting a flame in the combustion chamber;
• said ignition chamber including an air inlet port for inducting a flow of air into said ignition chamber;
• a swirler for swirling the flow of air inducted into said ignition chamber through said air inlet port;
• a fuel atomizer for inducting an atomized stream of fuel into said ignition chamber for mixing therein with the swirled air stream inducted through said air inlet port;
• a spark plug having an electrical spark gap disposed within said ignition chamber for igniting a flame within said swirled mixture of air and fuel within said ignition chamber;
• a single U.V. detector mechanically and optically operatively associated with the torch igniter for detecting ultraviolet radiation emanating from the igniter flame and the ignited flame in the combustion chamber.

In a method for torch igniting a gas turbine combuster operating at above atmospheric pressure and for detecting the existence of flame in a torch igniter and of flame in the ignited combustor, the steps of:

• flowing a swirling stream of torch air through a fluid passageway and inducting and expanding the swirling stream into an ignition chamber;
• mixing torch fuel into the swirling stream of torch air in said ignition chamber;
• selectively igniting the mixed stream of torch air and torch fuel to provide a torch flame, and exhausting the combustion products and torch flame from said ignition chamber through the wall of a combustion chamber into a combustion zone within the combustion chamber to ignite a combustion flame;
• passing U.V. radiation emanating from the torch and combustor flames back through said fluid passageway and a gas tight U.V. radiation transmissive window to a U.V. detector;
• scrubbing the combustion side of said window with the swirling flow of torch air;
• shutting off the torch flame in the ignition chamber;
• and
• detecting U.V. radiation from said combustion flame, if any, at said detector.