@Labestone Based on your question I think you may not be aware of the woodgas stoves. Please pardon me and reply if that is not the case. In woodgas stoves the fuel bundle is carbonized slowly through the fuel bundle. A small amount of air moves through the dry fuel to feed a small combustion zone in a pyrolysis process. The smoke moves through the carbonized char then combines with secondary air at a distance (a inch to a few feet) away from the fuel. (continue below...)
@jw934 The middle tube is to supply the secondary air in this natural draft (unpressurized/no fan) stove. It prevents the secondary air from reaching the unburned fuel, maintains cooking temperature (flame height+size), increase burn time, spreads the flame evenly under the pot, reduces soot, allows burning inside the stove to block wind. There are excellent woodgas stoves design for saw dust which does not have a middle tube, but for wood pellets they will fall through the hole.
@jw934 (Part 3)I didn't trying cutting holes in the tube so I don't know, but depending on the size of holes you want to cut I suspect they may cause flame to be lowered as the fuel level drops due to shrinkage from carbonization. The flame may steadily increase in size instead of maintaining constant size. If bottom holes are reduced in size to compensate, then there may be a lot of smoke when the stove flames out. Not sure about these but I am sure the stove will be more difficult to make.
Thanks for the information. I didn't know the alarm for CO2 gave that kind of info. Your new design is really efficient. You are very kind to share your work with us. The pot stand you use really compliments the efficiency of that system.
I can't wait to see the new stove. I had an idea about putting a regular 2 can wood gas burner with the bottom of the stove and the bottom of the inner can removed and then put on top of the donut stove, using the the upper stove/ 2 can wood burner as a chimney/ baffle top burner. I would increase the draft/efficiency and reduce the emissions. What do you use to measure your emissions? Could you show it on a video doing the measurements?
For a new concept (like the donut wood stove) it takes about 20 hours just to mentally picture the gas flow. Once I see it clearly in my mind, I build the stove freehand. About half the time the performance turns out exactly the way I imagined it.
A few more stoves that I will be sharing. One I am particularly excited about is the "nozzle stove". Ignite, place a pot of rice/water on it and come back to perfectly cooked rice that's kept warm. Only 32ppm of CO vs 176 for the donut
@jw934 I can't wait. I had an idea about putting a regular 2 can wood gas burner with the bottom of the stove and the bottom of the inner can removed and then put on top of the donut stove, using the the upper stove/ 2 can wood burner as a chimney/ baffle top burner. I would increase the draft/efficiency and reduce the emissions. What do you use to measure your emissions? Could you show it on a video doing the measurements?
@wmdrtr I measure using a home CO alarm with digital readout, run the stove on my dinning table and hold the alarm about 30 cm over the edge of the pot where I feel the hot exhaust. Lowest reading I got was when I cook my rice or spagetti using the new nozzle stove at 32ppm. Other stoves run to 400ppm when there is no smoke. Once the flame is gone, all stoves go to the 800ppm range with the charcoal pellets glowing. With cold winter here, I'll have to make the video when the family is out.
Thank you so much for sharing how you made it and the details. All the of the overpriced wood stoves are out of business if this video goes viral. What an excellent contribution for everyone's benefit , especially woodsman, campers, backpackers and even the economically or resource challenged people in the world. Are there any formulas you use to determine the amount of space required for air intake, size of burn chamber to pipe diameter and height or was it trial and error/guessing?
Excellent explanation. Thanks!
sc00f 1 month ago
What is the purpose of the middle tube? What happens if you just don't use one?
I see how you could not call it a donut stove but functionally, how does it help?
Also, if it is for draft purposes, would it be better to cut holes into it?
Thank you.
Labestone 3 months ago
@Labestone Based on your question I think you may not be aware of the woodgas stoves. Please pardon me and reply if that is not the case. In woodgas stoves the fuel bundle is carbonized slowly through the fuel bundle. A small amount of air moves through the dry fuel to feed a small combustion zone in a pyrolysis process. The smoke moves through the carbonized char then combines with secondary air at a distance (a inch to a few feet) away from the fuel. (continue below...)
jw934 3 months ago
@jw934 The middle tube is to supply the secondary air in this natural draft (unpressurized/no fan) stove. It prevents the secondary air from reaching the unburned fuel, maintains cooking temperature (flame height+size), increase burn time, spreads the flame evenly under the pot, reduces soot, allows burning inside the stove to block wind. There are excellent woodgas stoves design for saw dust which does not have a middle tube, but for wood pellets they will fall through the hole.
jw934 3 months ago
@jw934 (Part 3)I didn't trying cutting holes in the tube so I don't know, but depending on the size of holes you want to cut I suspect they may cause flame to be lowered as the fuel level drops due to shrinkage from carbonization. The flame may steadily increase in size instead of maintaining constant size. If bottom holes are reduced in size to compensate, then there may be a lot of smoke when the stove flames out. Not sure about these but I am sure the stove will be more difficult to make.
jw934 3 months ago
Thanks for the information. I didn't know the alarm for CO2 gave that kind of info. Your new design is really efficient. You are very kind to share your work with us. The pot stand you use really compliments the efficiency of that system.
wmdrtr 1 year ago
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I can't wait to see the new stove. I had an idea about putting a regular 2 can wood gas burner with the bottom of the stove and the bottom of the inner can removed and then put on top of the donut stove, using the the upper stove/ 2 can wood burner as a chimney/ baffle top burner. I would increase the draft/efficiency and reduce the emissions. What do you use to measure your emissions? Could you show it on a video doing the measurements?
wmdrtr 1 year ago
Nicely done. I like your design. Thank you!
FriarTuck1961 1 year ago
For a new concept (like the donut wood stove) it takes about 20 hours just to mentally picture the gas flow. Once I see it clearly in my mind, I build the stove freehand. About half the time the performance turns out exactly the way I imagined it.
A few more stoves that I will be sharing. One I am particularly excited about is the "nozzle stove". Ignite, place a pot of rice/water on it and come back to perfectly cooked rice that's kept warm. Only 32ppm of CO vs 176 for the donut
jw934 1 year ago 2
@jw934 I can't wait. I had an idea about putting a regular 2 can wood gas burner with the bottom of the stove and the bottom of the inner can removed and then put on top of the donut stove, using the the upper stove/ 2 can wood burner as a chimney/ baffle top burner. I would increase the draft/efficiency and reduce the emissions. What do you use to measure your emissions? Could you show it on a video doing the measurements?
wmdrtr 1 year ago
@wmdrtr I measure using a home CO alarm with digital readout, run the stove on my dinning table and hold the alarm about 30 cm over the edge of the pot where I feel the hot exhaust. Lowest reading I got was when I cook my rice or spagetti using the new nozzle stove at 32ppm. Other stoves run to 400ppm when there is no smoke. Once the flame is gone, all stoves go to the 800ppm range with the charcoal pellets glowing. With cold winter here, I'll have to make the video when the family is out.
jw934 1 year ago
Thank you so much for sharing how you made it and the details. All the of the overpriced wood stoves are out of business if this video goes viral. What an excellent contribution for everyone's benefit , especially woodsman, campers, backpackers and even the economically or resource challenged people in the world. Are there any formulas you use to determine the amount of space required for air intake, size of burn chamber to pipe diameter and height or was it trial and error/guessing?
wmdrtr 1 year ago