Patent ID: 7585481

Claim:
A method of making an ash from a feed material, the method including the steps: creating inner and outer vortices about an axis, the vortices defining a gas stream containing sufficient oxygen for exothermic combustion of the feed material and being arranged to flow in opposite axial directions and in the same angular direction, the vortices being arranged so that gas from the outer vortex meets the inner vortex to form a mixing zone; providing at least one ash outlet spaced axially from the mixing zone for collecting ash created from the feed material; feeding the feed material into the mixing zone where the feed material enters the inner vortex to create a centrifugal force component in the feed material thereby tending to cause the feed material to move outwardly into the outer vortex as the feed material travels axially in the inner vortex; carrying feed material received from the inner vortex into the outer vortex and into the mixing zone where this material from the outer vortex meets fresh feed material entering the mixing zone with resulting impact and thermal stresses in the feed material before the feed material is transported by the inner vortex for eventual entry from the outer vortex into the mixing zone, the feed material continuing to pass through the mixing zone until the feed material is converted predominantly to ash having escape criteria needed to travel to the ash outlet so that such ash will exit through the ash outlet leaving behind feed material that has not yet taken on the required escape criteria; monitoring temperatures in the gas stream; comparing the temperatures in the gas stream with known information to provide an output signal; and using the output signal to control the rate of flow of the feed material into the apparatus so that the feed material in the gas stream is subjected to temperatures selected to result in an ash having a desired content.