Abstract: Disclosed is an apparatus for introducing slurry fuels into the combustion zone of high power density combustors, boilers, industrial furnaces or steam generators. Having the general form of an elongate cylinder, the apparatus comprises a central conduit for a flow of particulate carbonaceous fuel suspended in a carrier liquid, and separate annular passageways for an atomizing fluid and a coolant. The slurry flows longitudinally to about the position where it is to be dispersed into the combustion zone, is there divided into a plurality of streams that are deflected to flow individually through a corresponding plurality of radially extending passages and slurry portholes spaced apart around the periphery of the cylindrical structure. Just before these streams leave the injector they are each impinged by a higher-velocity longitudinal flow of atomizing fluid which breaks the filaments of viscous slurry into minute droplets.

Abstract: In a combustion zone a fuel injector is immersed in a mixture of oxidant and products of combustion having a temperature of about 2000 degrees F. or higher. In order to maintain rapid and stable combustion, it is desirable to avoid excessive absorption of thermal energy from this mixture. To that end, the present invention provides means for impeding transfer of heat to the fuel injector from the adjacent mixture, such that portions of the mixture immediately adjacent the fuel injector may be kept at a temperature of approximately the ash-fusion temperature of the fuel, or higher, while the interior of the fuel injector is kept at a temperature substantially below the ash-fusion temperature. This means for impeding heat transfer preferably comprises at least one material having a thermal conductivity substantially lower than that of the fuel injector and, in a preferred embodiment, consists essentially of slag formed from noncombustible-mineral constituents of the fuel.