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Post by bmeagle on Apr 29, 2014 2:23:12 GMT -8
"triangle with the corners cut off". Do you mean a corner stove - maybe something like this one from the Netherlands?
Can you post a link to this stove project? Sent from my GT-N7000 using Tapatalk
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adiel
Junior Member
Posts: 119
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Post by adiel on May 11, 2014 7:11:35 GMT -8
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Post by pinhead on May 12, 2014 7:13:09 GMT -8
This is a really neat project - I've got a batch box in my shop but had to face it sideways so it doesn't take up so much room in my tiny building.
Using an "offset" riser like this sure would make the stove easier to load (and prettier to watch).
Very good work!
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Post by DCish on May 12, 2014 17:43:29 GMT -8
Been watching this thread... the side riser idea solves a significant space problem for me, it is so great to see that it functions well in practice. Thank you for sharing your work!
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Post by independentenergy on May 16, 2014 4:41:05 GMT -8
Hello Adiel Let me know if you have used the conventional calculations (p-channel, box dimension) to size the stove? The duct of the P-channel where it is located? nice work thanks
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Post by independentenergy on May 17, 2014 12:02:39 GMT -8
I had an idea for this design link
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morticcio
Full Member
"The problem with internet quotes is that you can't always depend on their accuracy" - Aristotle
Posts: 371
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Post by morticcio on May 17, 2014 22:55:02 GMT -8
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adiel
Junior Member
Posts: 119
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Post by adiel on May 22, 2014 10:56:14 GMT -8
hey independentenergy - yes we use peterbergs calculations. p channel is coming from the fromt and has two 90 turns. what did you think in the skp picture? i didnt understand. thanks for the encouragement
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adiel
Junior Member
Posts: 119
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Post by adiel on Jun 4, 2014 9:12:06 GMT -8
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adiel
Junior Member
Posts: 119
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Post by adiel on Jun 28, 2014 11:04:56 GMT -8
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Post by matthewwalker on Jun 28, 2014 13:01:34 GMT -8
Adiel, I would say it is working fairly well, considering the state of the build. Namely, some cob is still damp, and the metal ducting is exposed. It is shedding a LOT of heat on the way to the chimney, so there is not as much stack effect draft at the chimney as there will be when the ducting is covered, dry, and warmed up.
I do not think it is entirely unreasonable to have wisps of smoke coming out the door when it is opened mid-burn, that is normal in my experience.
Finally, I have found that the batch box must have almost no restriction and very good draft at the final chimney to work properly. They are much more delicate than a J in this sense. If they slow down much at all, they crash and although you didn't show it, as they slow they often smoke copiously out the chimney as well. This is one of the main reasons I tend to prefer J tubes for most builds, they are much more forgiving of final draft variations in my experience. This is in no way a strike against the batch, I think they are wonderful fireboxes. They just need a bit more careful tuning to work properly.
I would say you have a normal, well running batch there if it is working that well despite the excessive cooling of the exhaust gasses currently. I think it will work great once it's all complete.
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Post by peterberg on Jun 29, 2014 0:27:44 GMT -8
Adiel, Matt is right, those batch box thingies are like race horses, fast but nervous. Opening in mid burn is asking for smoking back, in the video it's clear the stove is running hotter, all the fuel is burning. When you really want to open it up, it's best to open it a little, wait a couple of minutes, open it a little further and wait again. This way, the fire will be given time to slow down. Regarding the manifold, the most important thing is the transition from wide to narrow. It's better to have some room below the duct at the narrow end, otherwise you are running the risk of having a restriction there. Having some room beneath the duct will create a larger stream profile for the gases to utilize. Something along the lines of the "Helpful hint" thread, placing the the duct straight on the floor the gases can only use the top rim and sides to stream through. The bench duct is a different shape as compared to the chimney and the riser. What I am trying to say, when comparing a round duct to a rectangle you shouldn't rely on the same cross sectional area. A reactangle of the same csa is unfavourable because it will cause more friction than a round duct. So the rectangle should be larger in order to carry as much gases by a given speed. The simplest formula is twice the width multiplied by the height, divided by width plus height. Looks like this in numbers: 2 x W x H / (W + H). This will give you the diameter of the comparable circular duct. When this is a smaller number than the system diameter you've found a serious restriction. And oh yes, a pulse at the height of the burn is more often than not a sign of friction somewhere in the system.
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Post by DCish on Jun 29, 2014 6:18:31 GMT -8
As someone who is currently burning a standard commercial box stove I can attest that it cannot run without wisps of smoke escaping while the door is wide open either. One feature that my current stove has that I am thinking of including when I build my batch box is a lip hanging down an inch or two at the front of the firebox. This gets in the way of loading a little bit, but it does make it harder for it to smoke back out the door during loading. One commercial stove I've seen has a two-inch hanging flap inside the front door of the stove that folds out of the way when a log goes in, then drops back down into place again to block smoke.
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adiel
Junior Member
Posts: 119
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Post by adiel on Jun 29, 2014 11:16:58 GMT -8
thanks all more confident we are now. i thought the puls mode is a sign of a good operation..
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adiel
Junior Member
Posts: 119
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Post by adiel on Jul 3, 2014 12:35:53 GMT -8
do you think that in a situation that the surrounding is at 30 c then the loss of temp on the way is much more critical because its harder to reach a good temp difference for the chimney?
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