Dual fuel lance with cooling microchannels

A lance for a burner comprising:

• an innermost conduit defining a first fluid passage and a plurality of first fuel injection channels, each first fuel injection channel terminating at a first outlet;
• an intermediate conduit circumferentially surrounding the innermost conduit, the intermediate conduit defining a second fluid passage and a plurality of second fuel injection channels, each second fuel injection channel terminating at a second outlet;
• an outermost conduit circumferentially surrounding the intermediate conduit, the outermost conduit defining a third fluid passage, a plurality of third air outlets through the outermost conduit and surrounding the first outlets, a plurality of fourth air outlets through the outermost conduit and surrounding the second outlets, and a plurality of cooling microchannels disposed in areas prone to high temperatures during operation;
• wherein the innermost conduit, the intermediate conduit, and the outermost conduit have respective conduit inlets co-axial with a longitudinal axis of the lance;
• wherein each of the innermost conduit, the intermediate conduit, and the outermost conduit comprises an upstream arcuate portion fluidly connected to the respective conduit inlet;
• a vertically oriented portion fluidly connected to the upstream arcuate portion and parallel to the longitudinal axis;
• and a downstream portion fluidly connected to the vertically oriented portion and transverse to the longitudinal axis, wherein the respective downstream portions of each of the innermost conduit, the intermediate conduit, and the outermost conduit comprise an upper curved surface and a lower curved surface;
• wherein the innermost conduit, the intermediate conduit, and the outermost conduit terminate in a tip portion that is perpendicular to the longitudinal axis of the lance;
• wherein each cooling microchannel includes and extends between a microchannel inlet defined through the outermost conduit and in fluid communication with the third fluid passage of the outermost conduit and a microchannel outlet on an outer surface of the outermost conduit to produce a cooling film along the outer surface;
• and
• wherein the plurality of cooling microchannels comprises a first set of cooling microchannels extending in a direction generally parallel to the longitudinal axis;
• and wherein the respective microchannel inlets of the first set of cooling microchannels are disposed in a common plane within the vertically oriented portion.

A lance for a burner comprising:

• an innermost conduit defining a first fluid passage and a plurality of first fuel injection channels, each first fuel injection channel terminating at a first outlet;
• an intermediate conduit circumferentially surrounding the innermost conduit, the intermediate conduit defining a second fluid passage and a plurality of second fuel injection channels, each second fuel injection channel terminating at a second outlet;
• an outermost conduit circumferentially surrounding the intermediate conduit, the outermost conduit defining a third fluid passage, a plurality of third air outlets through the outermost conduit and surrounding the first outlets, a plurality of fourth air outlets through the outermost conduit and surrounding the second outlets, and a plurality of cooling microchannels disposed in areas prone to high temperatures during operation;
• wherein the innermost conduit, the intermediate conduit, and the outermost conduit have respective conduit inlets co-axial with a longitudinal axis of the lance;
• wherein each of the innermost conduit, the intermediate conduit, and the outermost conduit comprises an upstream arcuate portion fluidly connected to the respective conduit inlet;
• a vertically oriented portion fluidly connected to the upstream arcuate portion and parallel to the longitudinal axis;
• and a downstream portion fluidly connected to the vertically oriented portion and transverse to the longitudinal axis and having a fixation system disposed within the downstream portion between the outermost conduit and the intermediate conduit, wherein the respective downstream portions of each of the innermost conduit, the intermediate conduit, and the outermost conduit comprise an upper curved surface and a lower curved surface;
• wherein the innermost conduit, the intermediate conduit, and the outermost conduit terminate in a tip portion that is perpendicular to the longitudinal axis of the lance;
• wherein each cooling microchannel includes and extends between a microchannel inlet defined through the outermost conduit and in fluid communication with the third fluid passage of the outermost conduit and a microchannel outlet on an outer surface of the outermost conduit to produce a cooling film along the outer surface;
• and
• wherein the fixation system comprises circumferentially spaced sets of hook-shaped elements extending radially inward from the outermost conduit and corresponding T-shaped pegs extending radially outward from the intermediate conduit, each T-shaped peg being disposed within a respective set of hook-shaped elements.