Pulverized solid fuel nozzle tip with ceramic component

A solid fuel nozzle tip for use in cooperative association with a pulverized solid fuel nozzle of a firing system of a pulverized solid fuel-fired furnace comprising:

• a. fuel air shroud means mountable in supported relation thereto at one end of the pulverized solid fuel nozzle, said fuel air shroud means having an inlet end and an outlet end, said fuel air shroud being comprised of at least one of the group of ceramics including silicon nitride, siliconized silicon carbide having a silicon content of between about thirty percent (30%) to sixty percent (60%) by weight, mullite bonded silicon carbide alumina composite, and alumina zirconia composites;
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• b. primary air shroud means mounted in supported relation within said fuel air shroud means;
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• c. fuel air shroud support means interposed between said fuel air shroud means and said primary air shroud means so as to be operative for effectuating the support of said fuel air shroud means relative to said primary air shroud means, said fuel air shroud support means being recessed from said trailing edge of said primary air shroud means by a predetermined amount sufficient to keep the recirculation region and vertical deposition surface created by said fuel air shroud support means away from said outlet end of said fuel air shroud means so as to thereby reduce the possible influence of said fuel air shroud support means on the deposition process and also sufficient to allow said outlet end of said fuel air shroud means and said trailing edge of said primary air shroud means to independently expand relative to one another thereby reducing thermally induced stress therein.

A solid fuel nozzle tip for use in cooperative association with a pulverized solid fuel nozzle of a firing system of a pulverized solid fuel-fired furnace comprising:

• primary air shroud means mounted in supported relation within said fuel air shroud means, said primary air shroud means having a leading edge and a trailing edge;
• fuel air shroud means mountable in supported relation thereto at one end of the pulverized solid fuel nozzle, said fuel air shroud means having an inlet end and an outlet end, said fuel air shroud being comprised of at least one of the group of ceramics including silicon nitride, siliconized silicon carbide having a silicon content of between about thirty percent (30%) to sixty percent (60%) by weight, mullite bonded silicon carbide alumina composite, and alumina zirconia composites and said fuel air shroud means includes at the inlet end thereof a bulbous configuration, said bulbous configuration being operative for the purpose of minimizing the bypassing of fuel air around said fuel air shroud means particularly when said fuel air shroud means is in a tilt condition and for the purpose of enhancing the cooling effect produced by the flow of fuel air through said fuel air shroud means, said fuel air shroud means also including rounded corners, said rounded corners being operative for the purpose of producing higher velocities in said rounded corners of said fuel air shroud means and thereby minimizing low velocity regions on said fuel air shroud means whereat solid fuel deposition could occur;
• fuel air shroud support means interposed between said fuel air shroud means and said primary air shroud means so as to be operative for effectuating the support of said fuel air shroud means relative to said primary air shroud means, said fuel air shroud support means being recessed from said trailing edge of said primary air shroud means by a predetermined amount sufficient to keep the recirculation region and vertical deposition surface created by said fuel air shroud support means away from said outlet end of said fuel air shroud means so as to thereby reduce the possible influence of said fuel air shroud support means on the deposition process and also sufficient to allow said outlet end of said fuel air shroud means and said trailing edge of said primary air shroud means to independently expand relative to one another thereby reducing thermally induced stress therein;
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• splitter plate means supported in mounted relation thereto within said primary air shroud means, said splitter plate means being recessed from said outlet end of said fuel air shroud means by a predetermined amount sufficient to remove said splitter plate means as a site susceptible to potential deposition thereon of solid fuel particles and sufficient to provide some cooling of said splitter plate means by virtue of the shielding provided thereto by said fuel air shroud means and said trailing edge of said primary air shroud means being recessed from said outlet end by a predetermined amount sufficient to remove said trailing edge of said primary air shroud means as a potential surface for solid fuel particles.