Burned coal here for years, I'm just outside pa hard coal country. Coal burns from underneath, you can blow air on top of burning coal and shut the bottom draft and it will die out. A grate of some sort, or a few 1/2 or 3/4 pipes with many drilled holes like a manifold in the bottom of your stove connected to a ball valve on the outside or some sort of damper will work. Gotta get air underneath. Now putting a little coal on top of wood, with I burnt wood and coals to act as a grate and allowing air flow will work.
