Apparatus for combustion of diverse materials and heat utilization

A combustion apparatus for particulate solids having a combustible component comprising

• a single cylindrical rotatable elongated combustion chamber consisting of a single tube having an unobstructed interior for a mechanical fluidization of said particulate solids by entraining said solids in a combustion gas and for rotation about a substantially horizontal axis, said tube having an ignition section at an upstream end with an inlet for receiving said particulate solids and a combustion section at a downstream end with an outlet for spent solids, said sections in horizontal series with one another for combusting said particulate solids,
• means for rotating said chamber about its horizontal axis,
• means for introducing said particulate solids having a combustible component into said chamber inlet,
• means for introducing an oxidizing gas into said chamber for combustion of said combustible component,
• a plurality of lifters on the internal surface of said chamber for lifting and cascading said particulate solids in said chamber for said mechanical fluidization of solids,
• means for passing a stream of said combustion gas through said chamber whereby combustion is achieved within said chamber with said mechanical fluidization of said particulate solids in said combustion gas during combustion, and
• means externally of the combustion chamber for recycling hot spent solids for mixing with said particulate solids after introduction into said chamber inlet, wherein said chamber and said lifters function as mechanical fluidization means responsive to a speed of said chamber rotation defined by the following empirical relationship:
• ##EQU2## in which A has a value between about 10 and 40 such that gas is entrained by the cascading solids resulting in said mechanical fluidization of said particulate solids in said combustion gas.