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Post by canyon on Mar 14, 2010 22:10:10 GMT -8
Better to use the 1/4" wall pipe cuz' if your steel burnt out the vermiculite/clay stuff would collapse with the weight of the tall riser (unless an ideal mix was developed that could vitrify and then hold it). With experimentation, a refractory cement/vermiculite might be a better choice or even better a firebrick heat riser with vermiculite/clay insulation. If you go 1/4" wall pipe you've got some years of burning anyway. Whatever you do, do it so that it is easy enough to take apart and rebuild!  |
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Post by spacevan on Mar 15, 2010 8:48:53 GMT -8
i was considering putting a thin consumable spacer around the metal heat riser that would burn away when the first fire is started that would make it easier to remove the metal heat riser if the bottom of it burnt away and replace it. But a fire brick heat riser insulated would probably be the best of all.
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hoota
New Member
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Post by hoota on Mar 16, 2010 8:23:28 GMT -8
If you made the heat riser with thin metal on the inside and outside and 6" thick vermiculite/fireclay inside.Perhaps add some cement to make it more like castable refractory so after the inside burned out the integrity of the tube of vermiculite/fireclay would remain in place.Would you use some supports around the outside like channel iron or angle iron,kinda like legs to support the heat riser and the weight upstairs?Or maybe a brick or block structure for strength.
Just to share some ideas:
Iam working on a design for a heat riser to go on top of a box woodstove with a barrel over it for radiant heat in my shop.To give the heat riser a solid inside layer,I was planning to coat a piece of stovepipe on the outside with Rutland furnace cement(maybe 1/4 to 1/2"thick) and then pour my fireclay/vermiculite mix in between the stovepipe and outer wall of thin metal,before the furnace cement cured so to kind of make it all one piece cast at once,which would have a hard heat resistant inner layer(after the stovepipe burnt away)in the heat riser.Then put the barrel over that for radiant heating
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Post by Donkey on Mar 16, 2010 12:37:48 GMT -8
A couple drawbacks of the brickwork riser:
At the height you're talking about, the thing is gonna be heavy which probably won't matter in a basement with a concrete floor. It's also going to be rather "teetery", it's a very narrow construct and rather tall for it's width. It just "feels" kind of unsafe, so I'd want some kind of structure on the outside to hold it all together well.
Another problem is that the bricks have a fairly high thermal mass and are likely to hold onto a lot of heat that you would rather have upstairs.
A little factoid in metal parts in rocket stoves: It has been noticed by quite a few stovers that metal bits inside these stoves don't burn out, even when they are exposed to high heat. there isn't a whole lot of oxygen left over after combustion, metal needs oxygen to burn as well as heat.
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Post by spacevan on Mar 16, 2010 18:25:01 GMT -8
With that being the case than that is good because i can get some 8" .250 wall pipe i thought that i would cap the bottom of the pipe and then T in a 8" square tubing or the fire brick heat tunnel, where the fire tunnel lines up with the heat riser. The heat riser would be on a refractory concrete pad or bricks maybe to help distribute the weight. It may also help if i welded a 1/4 or 3/8 plate at the back of the heat riser where the fire tunnel come in to give it that 90 degree bend to create turbulence. then insulate all around the heat riser. I really appreciate everyones comment and suggestions thanks.
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Post by spacevan on Mar 16, 2010 18:50:56 GMT -8
With that being the case than that is good because i can get some 8" .250 wall pipe i thought that i would cap the bottom of the pipe and then T in a 8" square tubing or the fire brick heat tunnel, where the fire tunnel lines up with the heat riser. The heat riser would be on a refractory concrete pad or bricks maybe to help distribute the weight. It may also help if i welded a 1/4 or 3/8 plate at the back of the heat riser where the fire tunnel come in to give it that 90 degree bend to create turbulence. then insulate all around the heat riser. I really appreciate everyones comment and suggestions thanks. |
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