I've been experimenting with a shop made wood boiler recently.
There are already threads here about primary and secondary air, and here about flue heat exchangers, which helped get this project going.
I started with some small TLUD rocket stoves, made out of tin cans, to try to get a start on an efficient design. I learned several things:
1. An extremely crude stove that has primary and preheated secondary air, can make a quite impressive rocket stove
2. I could burn darn near anything in it.
3. Wood chips burn pretty good in a "retort" or a sealed heated chamber that produces wood gas, which then feeds the fire and heats the chamber.
4. I can produce "biochar" in the retort, which is a good garden additive, captures carbon, or can also be used as fuel for the next firing.
Encouraged, I scaled it up to 55 gallon barrel sized. the current prototype is sitting in the driveway under a tarp, waiting for improvements.
Now, instead of posting a picture of a rusty old barrel with amateur welds on it, as you are expecting, I'll start by posting a drawing of what it is supposed to look like. See attached PDF. Rusty barrel pics come later. Basically this is a souped-up two-barrel stove kit from Vogelzang.
In test firings, this stove really can burn darn near anything. Cordwood of course, and almost 3 feet long. However it will also burn wood chips or shredded wood, which I can load up free at the City mulch site. I have about 2 cords of actual firewood seasoned, and about 2 cords of dry wood chips.
Wood you load with a shovel!
Next steps are: insulate the thing with something that does not burn ( I found rolls of rock wool at Menard's, will probably take more temperature than fiberglass), add a heat exchanger that can heat water, add a buffer tank and some circulating pumps, and plumb it into the house hydronic system safely. It all goes in an insulated and fire-resistant hut out on a porch.
There is some desperation to this project as my regular propane boiler bit the dust last year. The house is well insulated, solar, and has a small heat pump that won't let it freeze, but won't keep it comfortable either. All set up with hydronic floor heat and a hydronic coil on the air handler, just needs a hefty heat source. Nothing like being TOASTY warm on the cheap.
More to come, including pics of some of the tin can prototypes and the current state of the barrel stove.
Any suggestions as to improvements, or the location of a recommended mental hospital if you think this is nuts, would be appreciated.
There are already threads here about primary and secondary air, and here about flue heat exchangers, which helped get this project going.
I started with some small TLUD rocket stoves, made out of tin cans, to try to get a start on an efficient design. I learned several things:
1. An extremely crude stove that has primary and preheated secondary air, can make a quite impressive rocket stove
2. I could burn darn near anything in it.
3. Wood chips burn pretty good in a "retort" or a sealed heated chamber that produces wood gas, which then feeds the fire and heats the chamber.
4. I can produce "biochar" in the retort, which is a good garden additive, captures carbon, or can also be used as fuel for the next firing.
Encouraged, I scaled it up to 55 gallon barrel sized. the current prototype is sitting in the driveway under a tarp, waiting for improvements.
Now, instead of posting a picture of a rusty old barrel with amateur welds on it, as you are expecting, I'll start by posting a drawing of what it is supposed to look like. See attached PDF. Rusty barrel pics come later. Basically this is a souped-up two-barrel stove kit from Vogelzang.
In test firings, this stove really can burn darn near anything. Cordwood of course, and almost 3 feet long. However it will also burn wood chips or shredded wood, which I can load up free at the City mulch site. I have about 2 cords of actual firewood seasoned, and about 2 cords of dry wood chips.
Wood you load with a shovel!
Next steps are: insulate the thing with something that does not burn ( I found rolls of rock wool at Menard's, will probably take more temperature than fiberglass), add a heat exchanger that can heat water, add a buffer tank and some circulating pumps, and plumb it into the house hydronic system safely. It all goes in an insulated and fire-resistant hut out on a porch.
There is some desperation to this project as my regular propane boiler bit the dust last year. The house is well insulated, solar, and has a small heat pump that won't let it freeze, but won't keep it comfortable either. All set up with hydronic floor heat and a hydronic coil on the air handler, just needs a hefty heat source. Nothing like being TOASTY warm on the cheap.
More to come, including pics of some of the tin can prototypes and the current state of the barrel stove.
Any suggestions as to improvements, or the location of a recommended mental hospital if you think this is nuts, would be appreciated.
