Odd Man Out
11-29-2010, 16:28
I have been experimenting with my cat can stove.
http://www.whiteblaze.net/forum/showthread.php?t=66866
I recently turned my attention to wind screens. My first attempt was with regular aluminum foil folded into a strip 2 3/8 wide (so it would fit in my pot) and 22 inches long, held to form a ring with a large paper clip. It forms a ring about 1 cm diameter greater than the pot. The top edge of the screen is about an inch above the bottom of the pot when setting on my stove. I test in my basement on my work bench (a fragment of an old kitchen cabinet and counter top).
I first did a control without any air vents and it worked (the stove went out). I then used a hole punch to make vent holes every inch around the perimeter about a 1/2 inch from the bottom edge. On this test, the stove heated the water at about the same rate as the test without a wind screen (degrees per minute), but burned out faster so didn't heat the water as much. When done, I noticed the table top was very hot, even slightly melting my work surface. I suspect the extra heat inside the screen caused the fuel to boil more vigorously (thus burn faster). However the extra power and heat did not seem to transfer to the water and was wasted (by heating and melting the base surface)
I have seen a lot of wind screen designs on-line. When using a well enclosed alcohol stove, do you have a problem with excessive heat on your base surface (table/ground)? Do you use some sort of insulating base to protect the surface and/or reflect heat back to the pot? Do you do something to keep your stove from burning too hot? I know systems like the Caldera Cone use an enclosure to increase stove power and/or efficiency, but I am not seeing that. What works for you?
TIA for wind screen tips.
http://www.whiteblaze.net/forum/showthread.php?t=66866
I recently turned my attention to wind screens. My first attempt was with regular aluminum foil folded into a strip 2 3/8 wide (so it would fit in my pot) and 22 inches long, held to form a ring with a large paper clip. It forms a ring about 1 cm diameter greater than the pot. The top edge of the screen is about an inch above the bottom of the pot when setting on my stove. I test in my basement on my work bench (a fragment of an old kitchen cabinet and counter top).
I first did a control without any air vents and it worked (the stove went out). I then used a hole punch to make vent holes every inch around the perimeter about a 1/2 inch from the bottom edge. On this test, the stove heated the water at about the same rate as the test without a wind screen (degrees per minute), but burned out faster so didn't heat the water as much. When done, I noticed the table top was very hot, even slightly melting my work surface. I suspect the extra heat inside the screen caused the fuel to boil more vigorously (thus burn faster). However the extra power and heat did not seem to transfer to the water and was wasted (by heating and melting the base surface)
I have seen a lot of wind screen designs on-line. When using a well enclosed alcohol stove, do you have a problem with excessive heat on your base surface (table/ground)? Do you use some sort of insulating base to protect the surface and/or reflect heat back to the pot? Do you do something to keep your stove from burning too hot? I know systems like the Caldera Cone use an enclosure to increase stove power and/or efficiency, but I am not seeing that. What works for you?
TIA for wind screen tips.