jacob green wrote:
3. if I decide to use a sacrificial metal liner for the riser, that burns off, leaving the refractory material, what happens to that material? do any toxic compounds become embedded in the refractory material to be slowly released in exhaust over time? The reason I ask is because one of the applications will be exhausted very close to a chicken coop. I do not want zinc or other metals being exhausted in to their environment/runs.
John Elliott wrote: "4. Is there an ideal ratio for the inner dimensions of the core/heat riser/exhaust? Are there any rules dimension-wise which are especially critical while there is room for experimentation elsewhere? In particular, is the diameter of the airflow path the SAME ALL THE WAY THOUGH the system? Or do you need the exhaust portion of the path to have larger diameter than the core/riser to create lower pressure on the back end, to let the gasses slow down and get burned rather than being rocketed out the chimney cap before getting burned"
Troy Fairclough wrote:
your burn tunnel needs to be the tightest of all areas.
all areas past the burn tunnel need to be at least as large as the overall area of the burn tunnel if not bigger.
make sure that where you connect your exhaust to the burning unit that you do not cramp the space at that joinder.
if any areas are smaller in surface space than the burn tunnel the unit will not draft correctly from what i understand.
as far as having efficient burn that all comes down to the height of your heat riser.
thomas rubino wrote:add as much dry refractory as you can afford.