A quick rundown on how bituminous will burn in your stokermatic.. Berlin, if I'm way off in any of my descriptions, please feel free to edit my text.
First, there must be a hopper to store the coal to be burned,, there will be an auger, a big screw in the bottom of the hopper that will convey the coal to the bottom of that tube in the middle of your firechamber.. in the tube, which I call a burnpot or firepot, there will be air slots or holes, somewhere there is a fan that forces air through these holes or slots..
The coal is pushed into the bottom of the firepot, where the fire burns, air is forced into the fire, creating a very hot fire. As the coal is heated, but not yet ignited, Bituminous coal 'boils off' volitiles, these are trapped gasses in the coal,, these gasses need a lot of air to burn fully.. that curved tube that ends over the burnpot blows extra air into the coal flames and smoke to burn the volitiles completely. You should have very little black smoke once you get the fire going,, and it can burn for weeks, months or the whole season.
As the coal is pushed up from the bottom through the firepot, it boils off it's volitiles, which are burnt above, and the coal ignites, burning redhot, just like Anthracite coal.. Bituminous coal often has a high 'swelling index'. This means that as it gets hot and burns, it gets soft, and tends to 'glue' itself together into one big piece.. the burnpot usually gets larger as the coal rises in the pot, this allows the air and additional coal to not get 'stuck' behind a big piece of stuck together coal. The burnpot is shaped roughly like a flowpot, smaller diameter at the bottom than at the top.
As the coal is pushed higher in the burnpot it is more completely burnt,, and the heat fuses the ash together into clinkers.. In this type of coal burning and coal stove, clinkers are a good thing, the clinker is pushed out of the burn pot, and it stays in one piece on the flat refractory surface that surrounds the burnpot. The coal finishes burning on the refractory leaving behind large clinkers or hunks of ash.
These stoves do not have an ashpan, the stove operator has to open the door, and using a pair of 'clinker tongs', or a small hoe and shovel, scoop up and remove the clinkers and accumulated ash. Leaving room for the next batch of clinkers and ash. The fire keeps burning while the clean up is conducted..
I think I've covered the general operation of a Bituminous stoker stove.