This looks fantastic!!! You're doing a great job IMO. Heat exchangers set up much like Portage and Main. You're secondary combustion chamber looks a lot like my Wood Doctor. That uses all 8" square tubes, for the combustion chamber and for heat exchange to the water.. If this helps, my WD's nozzle is set up completely with refractory brick. They've lined it up crossways over the combustion chamber with 4 slots open to the combustion chamber of approximately 1" wide and 6" accross. Personally, I think the nozzle openings might be a little on the big side as I get a rather large amount of coals falling down through. Also the fire is not as intense as it could be (not the same torch effect that I get from my central Boiler) and I get a lot of ash to clean out every few days. Also the nozzle openings are favoring the front end of the firebox putting the hottest fire at the front causing the wood the burn more quickly at the front so I end up raking coals to the front at the end of the burn cycle.
For air supply, the Wood Doctor uses an easy option. First off it's a negative draft, a fan installed in the chimney sucking the air/fire through. I know that some of the bigger models on the market actually use both positive and negative draft together. Anyway, the Wood Doctor design just sucks the air in through a tube mounted so that the air is introduced at the wood fill door. That tube has a high heat flap with a motor attached to open/close. I'll get a picture tomorrow. Maybe it interests you. The only point I'd like to stress is this, Keep your primary air supply simple and/or removable for cleaning!!! I've had major issues with my Central Boiler primary air channel and finally had a welder come in and we put together my own design. Works better than ever, and I can clean it if necessary, which has not actually even been necessary. I'll post that pic now. Even Central Boiler has re-designed to allow removal for cleaning.
Keep up the good work. I look forward to seeing your progress. I wish I had a shop and knew how to weld.
Jeff
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