Gas turbine engine fuel injectors

A gas fuel injector for a gas turbine engine having a casing and a flame tube therein, said gas fuel injector being for use with gaseous fuels having a range of calorific values and comprising:

• a fuel nozzle positioned upstream of said flame tube for discharging gaseous fuel in a downstream direction toward said flame tube, said fuel nozzle extending through an opening in and being attached to said casing of said engine;
• and
• fuel and air inlet means downstream of said fuel nozzle, said fuel and air inlet means being fixedly attached to the upstream end of said flame tube and separately mounted with respect to said fuel nozzle, said fuel and air inlet means including an outer substantially annular passage containing air swirling means and arranged to receive a flow of compressed air and discharge the same downstream into said flame tube as a flow of swirling air in a direction generally parallel to the longitudinal axis of the flame tube, and an inner substantially annular passage for receiving gaseous fuel from the fuel nozzle and a flow of compressed air, said inner annular passage decreasing in cross-sectional area in a downstream direction and terminating in a downstream outlet aligned to direct the flow of gaseous fuel and compressed air discharged therefrom outwardly at an angle to the longitudinal axis of the flame tube into the flow of swirling air discharging from the outer annular passage.