Post by ztrain727 on Jul 28, 2014 12:31:26 GMT -8
Hello Ladies and Gentlemen -
In the works is a rustic device of leisure - an outdoor hot tub. The stove will be a drum with perlite/cement insulation and duct pipe riser with a copper heat exchange. Here's my plans... I owe thanks to many other's research and tips on youtube and other forums, so thanks!
Overview:
55 gal drum shell
Burn chamber - 7" ID (inner diameter) brick
Air/Fuel mixture - 4-5" ID hole in drum connected to 7" duct pipe insider
Heat riser - 7" ID x ~30" duct pipe link
Insulation - 4 to 1 perlite to cement
Heat exchange - 50' 1/4" ID copper tubing (filled with frozen water for smooth bending into coil)
Bottom 3rd of drum is filled with perlite/cement insulation (Ins.) around all duct pipe and 90 degree elbow. Remaining heat riser has 2" Ins. jacket. 2" Ins around interior of drum (remember we want this heat to go into the water, not the air). 6" exhaust hole ~15" from bottom of drum.
Copper heat exchange runs up from tub, into drum, into the top 12" of the heat riser where it forms a 6" ID x 12" coil and then runs down out of exhaust hole (in a large coil if there is excess tubing). I may also just have a small tub of water on top of the barrel that drains into the hot tub.
The tub (6'Lx4'Wx3'H) is approximately 500 gallons totally full, maybe 400 allowing for people, so a good bit of energy will be needed.
Questions:
1. Should the heat exchange be inside the heat riser (near the top) or will this degrade the rocket stove performance?
2. Should the hot gases be in direct contact with the copper tubing or should I heat a sleeve of water and put the coil inside (like a double boiler) - a question of both efficiency and durability?
3. Is my general stove design/dimensions sound?
4. Other comments/concerns/questions?
Thank you very much for this excellent resource! Any and all advice is welcomed!
In the works is a rustic device of leisure - an outdoor hot tub. The stove will be a drum with perlite/cement insulation and duct pipe riser with a copper heat exchange. Here's my plans... I owe thanks to many other's research and tips on youtube and other forums, so thanks!
Overview:
55 gal drum shell
Burn chamber - 7" ID (inner diameter) brick
Air/Fuel mixture - 4-5" ID hole in drum connected to 7" duct pipe insider
Heat riser - 7" ID x ~30" duct pipe link
Insulation - 4 to 1 perlite to cement
Heat exchange - 50' 1/4" ID copper tubing (filled with frozen water for smooth bending into coil)
Bottom 3rd of drum is filled with perlite/cement insulation (Ins.) around all duct pipe and 90 degree elbow. Remaining heat riser has 2" Ins. jacket. 2" Ins around interior of drum (remember we want this heat to go into the water, not the air). 6" exhaust hole ~15" from bottom of drum.
Copper heat exchange runs up from tub, into drum, into the top 12" of the heat riser where it forms a 6" ID x 12" coil and then runs down out of exhaust hole (in a large coil if there is excess tubing). I may also just have a small tub of water on top of the barrel that drains into the hot tub.
The tub (6'Lx4'Wx3'H) is approximately 500 gallons totally full, maybe 400 allowing for people, so a good bit of energy will be needed.
Questions:
1. Should the heat exchange be inside the heat riser (near the top) or will this degrade the rocket stove performance?
2. Should the hot gases be in direct contact with the copper tubing or should I heat a sleeve of water and put the coil inside (like a double boiler) - a question of both efficiency and durability?
3. Is my general stove design/dimensions sound?
4. Other comments/concerns/questions?
Thank you very much for this excellent resource! Any and all advice is welcomed!