Fuel injector and methods of use

A fuel-injection head comprising:

• a premix tube extending downstream from an injection body, the premix tube including at least one engagement member configured to engage with at least one corresponding engagement member of the injection body to removably couple the premix tube to the injection body;
• a plurality of vanes extending downstream from the injection body, wherein the plurality of vanes are arranged annularly around an upstream end of the premix tube;
• a barrel extending downstream from the plurality of vanes, wherein the barrel is annular around a downstream end of the premix tube, so as to define an annular passage that comprises a radial portion that extends radially through the plurality of vanes, an axial portion that extends axially between the barrel and the downstream end of the premix tube, and a transitional portion that transitions between the radial portion and the axial portion;
• and
• a splitter that splits the annular passage into a first annular passage and a second annular passage,
• wherein the premix tube is removable from the injection body, and wherein the fuel-injection head further comprises the injection body,
• wherein the injection body comprises a threaded aperture, and wherein an upstream end of the premix tube comprises the at least one engagement member, the at least one engagement member including a threaded radially outward facing surface that is configured to mate with the threaded aperture,
• wherein the injection body further comprises at least one radial aperture that radially extends through a radially outward facing surface of the injection body, through the injection body, and into the threaded aperture, and
• wherein the fuel-injection head further comprises a radial pin that engages with the threaded radially outward facing surface of the premix tube, through the at least one radial aperture, to thereby prevent rotation of the premix tube with respect to the injection body.