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Post by Orange on Nov 3, 2020 8:41:58 GMT -8
I've placed exit port horizontally on the side top to avoid top gap (and lower height of the stove):
this is pretty close to the placement of the regular exit port, what do you think? If the draw won't be good I can place it vertically or englarge it to full CSA (like batchblock).
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Post by viktrych on Nov 30, 2020 5:11:04 GMT -8
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Post by nixsee on Dec 26, 2020 13:30:47 GMT -8
Here's a DSR II open system Calculator: Thanks so much everyone - Peter especially - for the great information shared here. I'm excited to give this a try at a very small scale - 3 or 4" diameter rise. However, these links for the calculator don't appear to work anymore. Does anyone have a version that they can upload again? |
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Post by josephcrawley on Dec 26, 2020 14:02:08 GMT -8
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Post by nixsee on Dec 26, 2020 15:14:35 GMT -8
Thanks, I didn't know that you could scale in Sketchup. I'll give that a try, but I'm still hoping to have a spreadsheet where I can see the various numbers and do custom calculations for materials, modifications, etc..., so hopefully someone has the excel file or that Orange can upload it again! |
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Post by Orange on Dec 27, 2020 8:36:47 GMT -8
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Post by nixsee on Dec 28, 2020 7:37:15 GMT -8
Thanks!
I have a couple questions about dimensions for the various batchbox designs. I'm well aware that they are tightly spec'd, but am trying to work with the materials and space that I have. Also, it seems to me that an open batchbox's specs would be loosened compared to a closed one.
1. In an open batchbox, does the depth matter much? So long as it is not over or under loaded with fuel, could it be very deep or very shallow? What would happen if wood was sticking out the front, as with a traditional L tube?
2. Traditional rules of thumb that I've found for L tube cookstoves suggest a riser height that is 2.5-4x its diameter, and I've been happy with some 2.5x stoves that I've made. Conversely, the original straight BBR has a riser height of about of 6-8x, if I'm not mistaken. DSR I and II shorten that considerably by having an expansion area after the riser (following on from experimentation with tapered risers, I believe). Still, why are batchbox stoves so much taller than L tube guidelines? Is it that the guidelines are simply a compromise to make it functional as a cookstove? If so, would these batchbox cores - specifically the original straight BBR without topbox - still work (albeit with lower performance) with a shorter riser?
Again, I'm not trying to improve on this at all - just trying to "make do" with what I've got and want to avoid unnecessary work and expense if possible.
Thanks!
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Post by foxtatic on Dec 30, 2020 11:33:06 GMT -8
1. In an open batchbox, does the depth matter much? So long as it is not over or under loaded with fuel, could it be very deep or very shallow? What would happen if wood was sticking out the front, as with a traditional L tube? I can't speak to the second question, but for this first one: Dept still matters, even in an open batch box DSR2. The firebox can be up to 25% deeper (longer.) The stumbling block still gets placed at the halfway point on the ceiling of the top box, and exhaust port a quarter from the front. That's assuming you elongate both the firebox and the top box, which I would recommend since I've never seen a DSR2 with a funky looking top box that's shorter than the firebox below it. Regarding wood sticking out: What I learned from experience and guidance from Peter is that even an open DSR2 still needs some sort of "door" to block 50% to 60% of the firebox opening. That was something I misunderstood studying this thread, so I tried running mine with no door and the burns were awful, uneven, with smoke coming out the front of the firebox. Just by slapping together some scrap ceramic fiber board to block around 60% of the opening made it all better. Which is a long way of saying no, you can't leave wood hanging out because you need a door. And anyhow, wood hanging out would just fall out as the fire burned down to it, or burn on whatever surface it rested on with it's smoke rising into the room instead of getting sucked through the system reliably. Here's a pic of my temporary "door" permies.com/t/152831/a/128569/Door.jpg |
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Post by nixsee on Dec 30, 2020 12:57:56 GMT -8
Thanks very much for the detailed reply! Yesterday I made a prototype of a 3" system whose firebox was perhaps a bit long and wide open front. As you say, it was a mess - smoke coming out front etc. Maybe when it gets to temp and has draft it is better.
Anyway, in light of all this I think I'll abandon it - my goal is a very simple stove for poor people in the developing world to not just use, but build themselves. Standard L tube ones work well enough and accommodate long pieces of wood, etc...
Though I may make larger DSR for my own use at some point.
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Post by josephcrawley on Nov 30, 2021 15:54:54 GMT -8
Peter why haven't you added the dsr2 to your
batchrocket.eu site?
Thanks
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Post by peterberg on Dec 1, 2021 1:12:13 GMT -8
Peter why haven't you added the dsr2 to your batchrocket.eu site? In fact I did, ehrmm... sort of. I wrote an addition to the Designs chapter, although in Dutch only at the moment. This addition isn't complete as yet, most of my (somewhat limited) energy is devoted to the development of the commercial DSR3 version at this time. If and when this Dutch addition is ready I need to channel some effort to a translation into English which in turn will be used as the basis for all other translations. In case one is interested: go to batchrocket.eu/ontwerpen#DSR and ask Google to translate into whatever language. I won't be accountable for the quality of this translation, though.  |
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Post by josephcrawley on Dec 1, 2021 6:12:49 GMT -8
In case one is interested: go to batchrocket.eu/ontwerpen#DSR and ask Google to translate into whatever language. I won't be accountable for the quality of this translation, though. Google did a decent job translating. With the exception of a few awkward words it was very clear. Thanks for the response. Hope your winter is going well. |
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Post by Solomon on Dec 21, 2022 11:37:32 GMT -8
Hello there, I'm in the planning process for a DSR2 after operating a J-tube for 2+ winters, so I thought it fitting that I read this whole thread, and now I have completed it, and I found this very interesting tidbit. I would love to create a larger oven space. When I was fresh out of high school, I built an oven for our home wood stove, just a regular steel unit, and it worked well, you just had to turn the lasagna around half way through the cook. It's still there in my childhood house. So my question is, did you ever build this? How well does it work? I downloaded your drawing and if there are no objections, I want to try to build it in an 8" version, in a large brick bell, out of precast refractory blocks, more or less like you show in your drawing. One adjustment I would like to make is to make it out of more pieces, specifically splitting the slabs up into smaller sections longitudinally so if the slab is really hot on one end and less hot on the other end, there will be ~2 joints in that distance so as to reduce risk of cracking. I haven't seen anybody do it this way, but that's how my mind is working with it. I want this to last as long as possible before requiring a rebuild. |
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matt1
New Member
Posts: 4
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Post by matt1 on Feb 5, 2023 12:25:08 GMT -8
In the closed version of DSR2 is the riser floor at the same level as the top of the horizontal feed tube of the secondary air? Or is the riser floor at the same level as the floor of the firebox which is the tops of the full firebricks to the left and right of the recessed horizontal feed tube (this is the way it appears in all of the sketchup drawings I have seen)? Thank you for developing this core, it is exceptional.
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Post by peterberg on Feb 5, 2023 13:28:52 GMT -8
In the closed version of DSR2 is the riser floor at the same level as the top of the horizontal feed tube of the secondary air? Or is the riser floor at the same level as the floor of the firebox which is the tops of the full firebricks to the left and right of the recessed horizontal feed tube (this is the way it appears in all of the sketchup drawings I have seen)? Thank you for developing this core, it is exceptional. The drawings are correct, this is done out of simplicity. The bottom of the trench where the floor channel is in, is at the same level as the riser's floor. The port is measured from the top of the floor channel's feed, or horizontal duct in your words. Incidentally, this was the configuration that worked best as well. |
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