Pre-heating the Charcoal/feedstock with exhaust gasses

I am still in the first experimenting phase here, i will need to find out the best way to “use” the exhaust gasses heat in the process.
I want to make a “simple” build and do the “tweaking” step by step in de sub sequential learning process.

I need to ad / mix the extra heat needed and learn how to do that the most efficient way.
The pulse effect from the exhaust might be helpful to keep the charcoal “stirred up” either with positive or negative results.

So my first approach is, to make a “mixer” for the exhaust / HHO and connect that with the reactor.
The HHO will reach 2900°C, need to bring it down to 1300°C or below ashmelting temperature at all times