From the patent:
http://www.freshpatents.com/Stagnation-point-reverse-flow-combustor-for-a-combustion-system-dt20060209ptan20060029894.php?type=description
" ...When the liquid fuel is burned in a non premixed mode, the fuel is injected separately into the combustor through an orifice aligned with the axis of the combustion chamber and the combustion oxidant is injected in through an annular orifice surrounding the fuel orifice in the manner similar to that used to burn gaseous fuel in a non premixed mode, as described above. As in the non premixed gaseous fuel combustion case, the oxidant stream is confined within two shear layer at its inside and outside boundaries. In the inside shear layer, the oxidant mixes with the injected liquid fuel stream. In the process, liquid fuel is entrained into the shear layer where it is heated by the air stream. This heating evaporates the liquid fuel and generates fuel vapor that mixes with the oxidant to form a combustible mixture. In the outer shear layer, the oxidant mixes with the counter flowing stream of hot combustion products and reacting gas pockets. The resulting fuel-oxidant mixture that is formed in the inner shear layer is ignited and burned in essentially premixed mode of combustion when it comes into contact with the mixture of oxidant-hot combustion products-reacting gas pockets mixture that formed in the outer shear layer."
The exhaust is remixed with the combustion air. Sounds cool.
Years ago, a friend of mine took the "blow by" on his '61 Falcon and routed it back into the the air intake by using an old bike inner-tube. His blue cloud disappeared for about a week, and then the whole thing just croaked from carbon build-up.
Thanks for the memory.
not knocking anything here but - the device is meant to run cool to avoid high temperatures and NOX emissions, it burns fully by having good mixing.
Oh by the way, virtually every new car and truck is already circulating post - combustion gases to keep down peak reaction temperatures.