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Post by briank on Jan 3, 2017 23:59:46 GMT -8
I have my 6" batch box stove built but I'm still building a masonry bench so I have not fired it up yet. I bought an indoor portable 6'x11' therapy pool for rehab and exercise following strokes last spring, and I'm incorporating 100' of copper tubing coils in the bench with a 12v circulator pump so I can heat the pool water with the heat from the bench. It's open ended similar to a thermosiphon so steam should not be an issue. I found a barrel stove cheap on Craigslist so I laid that on its side and cut that in half to use the door end on the stove and as a base to build on, and the other half as a manifold for the end of my 8' bench. I mixed a bag of concrete and poured it in the half of the barrel with the door for a base for the big firebricks that make up the sides of the stove to stand on. I used a 6" bimetal hole saw to cut the flue holes in the 55 gallon barrel and the bench manifold.    |
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Post by briank on Jan 4, 2017 0:07:11 GMT -8
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Post by briank on Jan 4, 2017 0:10:48 GMT -8
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Post by briank on Jan 4, 2017 0:14:03 GMT -8
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Post by briank on Jan 4, 2017 0:41:40 GMT -8
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Post by briank on Jan 4, 2017 1:00:28 GMT -8
The bench will be 8' long x2.5' high x2' deep but due to the 4.5" thickness of the firebricks the internal surface area will be a good bit smaller. I haven't done the math yet but I suspect it's well within the limits.
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Ralf
New Member
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Post by Ralf on Jan 4, 2017 1:37:46 GMT -8
Hi Brian,
I´m amazed because I recently had the exact same idea of shaping channels in insulative firebricks located at the port to provide the secondary air.
The only possible flaw I can suspect at your design is that when you feed the air to the 45° upward channels from the bottom only the 2 lower ones will have access to the supply channel.
From my understanding most of the crucial mixing sould take place in the upper part of the port. Maybe you can carve an additional vertical supply channel that stops at the highest diagonal supply channel at the rear part of the firebricks .
Just my 2 cents.
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Post by briank on Jan 4, 2017 1:44:44 GMT -8
Hi Brian, I´m amazed because I recently had the exact same idea of shaping channels in insulative firebricks located at the port to provide the secondary air. The only possible flaw I can suspect at your design is that when you feed the air to the 45° upward channels from the bottom only the 2 lower ones will have access to the supply channel. From my understanding most of the crucial mixing sould take place in the upper part of the port. Maybe you can carve an additional vertical supply channel that stops at the highest diagonal supply channel at the rear part of the firebricks . Just my 2 cents. Here's a better detail of the finished ceramic fiber board channels and the firebrick that stands in front of each. Does that clarify your concern?  |
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Post by briank on Jan 4, 2017 1:56:04 GMT -8
I've also subsequently lined the left and right hand walls of the firebox above the angled firebrick with stainless steel to prevent abrasion of the fiber board from firewood.
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Ralf
New Member
Posts: 42
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Post by Ralf on Jan 4, 2017 2:12:24 GMT -8
Yep, I was obviously just lacking that very detail, superb !
Looking forward to see how it performs, since my build might take a few months until finished.
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Post by matthewwalker on Jan 4, 2017 5:28:30 GMT -8
Nice to see it coming together, it looks good Brian!
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Post by briank on Jan 4, 2017 5:53:12 GMT -8
Nice to see it coming together, it looks good Brian! Thanks Matt! That secondary air supply is completely theoretical since I haven't fired the stove yet and I haven't seen it tried anywhere. Any thoughts or concerns before I do? |
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Post by matthewwalker on Jan 4, 2017 5:58:10 GMT -8
I suspect that as far as you will be able to tell it will work fine. You can always just drop in a floor channel and plug your corners and see if there is a visible difference. I think it's gonna work though.
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Post by briank on Jan 4, 2017 10:57:31 GMT -8
I'm developing an idea for cheap/easy movement/distribution of heat away from a rocket mass heater using a body of water as a "heat sink." Please let me know if this idea isn't feasible for any reason that I might be overlooking.
It would be an open system, and would involve using one or more of those 67 gallon galvanized stock tank/troughs from Tractor Supply. You could camouflage one (or not) where you need the heat and fill it with water, cover it with cheap pieces of solar cover to prevent evaporation, then use garden hose, pex tubing or PVC and a solar/12v circulation pump to run water to a masonry bench, heat it by running it through copper coils in the bench, then return the heated water to the trough/tank. You'd "store" that heat in the trough to be slowly released in the room you need to move the heat to.
Many people run copper tubing coils through barrel stoves next to their pool in a similar fashion to successfully heat their pool, with the water supplied by a separate circulator pump or diverted from the main pool pump/plumbing. The copper is directly exposed to the wood flame but these are open systems, limiting risk of steam explosion. Water temp typically enters around mid 70's and returns heated 30+/- degrees hotter.
I'm limiting my copper tubing coils to the masonry bench to further minimize risks.
The reason I believe this would work is that when our kids were small, I put a 10'x15' oval above ground pool in our basement for fun/exercise. We had a Craigslist electric heat pump pool heater from a 28' round pool to heat it, and the electricity we burned to heat that pool was way more than offset by the money we saved in natural gas heating costs for our old drafty house. The body of water in the pool acted as a big heat sink that slowly heated the house from the basement, even though the pool temp was only in the 80's.
I'm using a 6'x11' x4' deep therapy pool for this purpose in my basement with cpvc tubing to run the pool water to the rocket heater bench and back. I'll use a solar cover to minimize evaporation/humidity issues.
A system of several of those troughs/tanks could be heated with simple garden hoses with a 12v circulator pump easily/cheaply, heating various areas as needed. The 12v 3gallon per minute pump from Harbor Freight is only $32.95 right now and has threaded input and outputs for garden hoses and will run on a cheap jump starter battery that's kept plugged in or charged with solar panels or a thermoelectric generator on the wood stove.
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Post by peterberg on Jan 4, 2017 11:52:49 GMT -8
I lined the firebox with 1" ceramic fiber board and created a unique secondary air delivery system out of firebrick and channels in the ceramic fiber board in front of the ceramic riser. I haven't fired it up yet but I have no reason to think it won't work. Please let me know if I'm missing something! Hi Brian, As far as I am aware this should work as long as the feed to the holes is twice as large as the combined holes. I am sorry to contradict you, but something similar has been done by a guy from the Netherlands with the intention to market the heater commercially so the secundary air supply isn't unique. And Yasin Gach, the French translator of the batchrocket site has done also something like yours during last fall. Not with holes but with a slit between two split firebricks. In order to get it to work properly you need to make sure the secundary ports are fed at all times while you reduce the primary inlet during the height of the run. Can be done with a steel piece which blocks part of the firebox, similar like what I used for the floor channel. You suggest by PM this could be as an alternative included in the batchrocket site. Could be, but I don't have real test results and figures yet from neither yours nor the others. Yasin has bought a Testo 330 so he could test the one he built, but that build wasn't close to his home town and in a customer's house. |
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