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Post by Donkey on Feb 29, 2012 17:28:38 GMT -8
When i calculate the heat transfer area i view the outside area. But I don't know what's up with inner area. So i need enough heat to transfer to the outer area. Right. It's not TOO hard to build a bell who's exterior dimensions are correct, but where the interior dimensions are too small. Harder to do the opposite. A slightly generous interior area will almost guarantee an appropriate exterior. The interior area will be the more critical limit. I like my stove, the horizontal feed is rather convenient. I gotta admit though, the wood isn't in the best place for complete combustion as often as a down feed. It's a trade-off fer sure. Either way you cut it, you've got some experimentation ahead. Please to post yer progress! ??
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Post by Donkey on Feb 29, 2012 8:59:23 GMT -8
I could be wrong about this, but.. I believe you need to calculate the INSIDE area of the bell, not the outside. Also, I'm not too sure about the double heat riser thing. The horizontal feed won't be as efficient as you would like, it will be far more fiddly than a vertical arrangement, you'll be constantly shoving the wood forward. The horizontal run of the feed to the second heat riser (to the heater) looks a bit long, it should be half of the length of the heat riser or less. The bell won't act as a bell should with the heat riser terminating at the top. Inputs to the bell should come in at the bottom or heat will be pumped through too quickly. The space at the top (above the heat riser) may still act as a bell but it will make for a relatively small one and I'm not sure how to judge how effective it will be. It is an interesting concept. You have some experimentation ahead if you really want to do it in this way. Personally, I'd go with one heat riser, run the heat through the cooking area first, then into the bell. It's likely that you could fit a double bell system in the same outer shell as you've planned here (or very nearly the same). I'd place a removable plate directly over the heat riser so that a pot (or pan) could be placed directly on the fire, perhaps two, one in the hot spot and one to simmer with a path between (like a Lorena stove). Flue gasses would pass through the cooking area and into the bottom of the first bell which would be above, then they would pass through a channel which would take them to the bottom of the second bell below and out the chimney in the same place (or roughly so) as you've shown. It seems to me that a smaller bell above would provide a hotter place for the oven while leaving enough heat to drive the rest of the machine. You may need a bypass of some sort to get the thing started.. Peterberg would be the best judge as to whether the thing would work or how well. In any case, you've got some experimenting to do.
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Post by Donkey on Feb 26, 2012 12:09:13 GMT -8
I have not heard of an oil drum that has burned out or rusted out yet. There is a stove that I know of that is over 10 years old, the barrel is still in perfect condition.
There shouldn't be enough oxygen inside to burn the barrel, nor should it ever get hot enough to melt it.. It seems to me, then, that the barrel's greatest enemy will be rust. I have noticed that they tend to rust right at the connection between the barrel and cob. Seems that stove paint or oiling the barrel (like cast iron pans) would help here a lot. Though, honestly, even if you let the things rust on their own time with no help whatsoever, they should last for a good long time.
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Post by Donkey on Feb 22, 2012 20:13:51 GMT -8
I've got a 15 gallon tank inside an 8 inch system somewhat similar to what is pictured in that post. I can't give you output numbers but I can say that 3 loads of wood will heat the water to just this side of boiling. About 20 minuets for a good hot shower and once it's hot, it can be fed while people take (modest) showers about 5 minuets apart, back to back until everyone's had a crack at it. Once, during a workshop, we ran 10+ showers in a row and we boiled the tank at the end (while a shower was in progress) and popped the safety valve doing it..
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Post by Donkey on Feb 22, 2012 15:05:23 GMT -8
Right. According to theory, since the heat riser is the acting stack and it is quite short, (compared to a standard chimney) it needs to run very hot to provide draft. Yes, the insulated heat riser and burn tunnel are almost a requirement.
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Post by Donkey on Feb 21, 2012 12:17:36 GMT -8
pluton5 I do not use blowers or other moving parts in my stoves. In my opinion, moving parts require unnecessary energy inputs, regular maintenance and invite breakdown at inopportune moments. I do think that your plan will work. The blowers will remove heat very quickly so your horizontal pipe will need to be shorter than it would be in a passive system. At the end, the exhaust needs enough heat left over to drive the chimney. I recommend that you find a safe place to build a test stove and experiment with your design. I'm not sure what you are asking. Likely a bad translation. Can you say this in a different way? pluton5Nie używam dmuchawy lub innymi częściami ruchomymi w moich pieców. Moim zdaniem, ruchomych części wymagało zbędnych nakładów energetycznych, regularna konserwacja i zaprosić podział w nieodpowiednich momentach. Myślę, że twój plan będzie działać. Dmuchawy usunie ciepło bardzo szybko dzięki czemu poziome rury trzeba będzie krótszy niż byłoby to w pasywny system. Na koniec wylotowy musi wystarczającą ilość ciepła, które zostały po jechać komin. I zaleca, aby znaleźć bezpieczne miejsce, aby zbudować piec testowy i eksperymentować z projektu. Nie jestem pewien, o co prosicie. Prawdopodobnie złe tłumaczenie. Czy możesz powiedzieć to w inny sposób?
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Post by Donkey on Feb 18, 2012 18:06:56 GMT -8
OK.. It looks like you're sticking with the "turbulator" shape below the heat riser. Does it stay because the theory is good or has it been proven by test? It's difficult to recognize the turbulator from the cutaway view. Could you show the "Peter Channel" a little more clearly? What's yer system size?
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Post by Donkey on Feb 18, 2012 18:03:33 GMT -8
Oh, that's clever! What's the refractory lookin' stuff around the feed? Looks a bit like wood-ash/clay..
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Post by Donkey on Feb 18, 2012 13:01:04 GMT -8
Wow.. That's cool! I'd like a peek inside that burn tunnel..
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Post by Donkey on Feb 17, 2012 10:36:05 GMT -8
Pluton5, I think that this deserves it's own thread, so I have moved it here.
Interesting design. I see only one flaw at A, the air intake. Air should pass down over the wood from above, not from below as shown. Bringing air into the system from below will cause smoke to fill the feed chamber above, causing a sticky creosote mess in that place, also when the door is opened smoke will stream out the top. I recommend something similar to the image below.
Myślę, że zasługuje na swój własny wątek, więc przenieśli go tutaj.
Ciekawe wzornictwo. Widzę tylko jedną wadę w A, wlotu powietrza. Powietrze powinno przechodzić w dół na drewno od góry, nie z dołu, jak pokazano. Wprowadzanie powietrza do systemu z poniżej spowoduje dym do wypełnienia komory podajnika powyżej, powodując lepki bałagan kreozotowy w tym miejscu, także wtedy, gdy drzwi są otwarte dym przesyłać na szczyt. Polecam coś podobnego do obrazku poniżej.
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Post by Donkey on Feb 14, 2012 10:47:21 GMT -8
I have tried a couple of different conic heat risers.. My results have been inconclusive thus far.
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Post by Donkey on Feb 12, 2012 16:36:39 GMT -8
Section 2.10 is the bit that wouldbe difficult with RMHs. It requires "the outlet from a flue should be above the roof of a building in a position where the products of combustion can discharge freely and will not present a fire hazard, whatever the wind conditions."I don't understand why this would be a problem.. A properly built flue is helpful in any circumstance, isn't it?
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Post by Donkey on Feb 11, 2012 10:56:52 GMT -8
Yer probably right, the two step gasifier/rocket is going to loose heat outside at the gasifier end of things.. It might be worth it depending on why you'd need the thing in the first place.. My idea was to keep the smoky bits outside, also to keep the inside of the sauna dark (it was modeled after the native american sweat lodge) and I wanted the heat in the center of the room. At the time, it seemed that the gasifier would solve for all that. The pyrolysis would take place over six feet away and outside of the building. My thought was to stream the woodgas into the building and ignite it there under a heat riser. 'Course, I never built it, nor did I start any of the testing so there are a LOT of issues that I didn't even begin to figure out. In the end, it was simpler to just build the rocket stove inside.
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Post by Donkey on Feb 11, 2012 10:47:42 GMT -8
I believe you can build a six inch system. If you cool the flue gasses enough, they will more easily fit through the smaller diameter. This is going to take some experimentation. Is there a place outside or under a well ventilated roof (a safe place from smoke etc.) where you can build a test model?
I imagine that some kind of bell stove arrangement might work best, or maybe an over-sized gap at the barrel and a length of bench I would use a 6 inch rocket stove feed and heat riser. The six inch system has a 28.27 square inch cross section area, and the 4.7 inch pipe has a 17.35 square inch cross section area. Your exit flue is more than half of the system size, which will be tricky but possible.
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Post by Donkey on Feb 10, 2012 12:33:49 GMT -8
I personally don't know the answer to that.. If rocket stoves (as such) are unknown to the building dept. near you, you might try to slip it in as a Masonry Stove, which IS recognized.
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