Method and apparatus for the recovery of hydrocarbons
A steam generator for burning a normally-solid fuel which produces non-combustible solid residues, including, an elongated combustion chamber, a fuel introduction means to introduce fuel adjacent the axis of the combustion chamber as a centrally-disposed stream moving in a downstream direction, a combustion-supporting gas introduction means for introducing the gas as an annular, rotating stream about the fuel stream and which, together with the fuel introduction means forms a rotating, toroidal vortex of the fuel and the combustion-supporting gas moving in a downstream direction. The combustion chamber has a volume sufficient to burn all of the fuel and, together with the fuel introduction means and the combustion-supporting gas introduction means, cause the vortex to collapse and form plug flow thereafter. Water introduction means introduces water into the flue gas at the downstream end of the combustion chamber as a plurality of peripherally-arranged jets. Preferably the water is introduced from the vena contracta of a nozzle-type orifice. A vaporization chamber, coupled to the combustion chamber, has a volume sufficient to vaporize a major portion of the water to steam and a separator separates solid residues from the flue gas-steam mixture.