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Post by contadino on Apr 2, 2020 9:25:29 GMT -8
Hi, i just finished my maple syrup making for the year. I'm using a home made barrel stove and two steam pans. I go through a ton of wood and can't really get the front to boil. It is more of a preheat pan.
I have a new 55 gallon barrel and would like to make a better evaporator. I was thinking of a rocket burner under each pan. So two 6" rockets and one 8" exhaust flue. But after reading the rocket stove guide and a bunch of these threads it seams that i would to fabricate an extension in order to get a tall enough riser. Now I have been reading about stoves with short risers or double shoebox stoves etc. Now I am totally confused. Can anyone point me in the right direction?
I was going to add a photo of my current set up but have to figure out how to do that...
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Post by Vortex on Apr 2, 2020 10:27:11 GMT -8
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Post by hallinen on Jun 17, 2020 14:33:57 GMT -8
First off I want to thank everybody who posts here, I find the discussions mentally therapeutic! I've been moving bricks around for my outdoor camp stove for a couple of years. I change the configuration of the bricks depending on if I'm boiling maple sap, or cooking or doing a campfire. The current version is a batch boxish design with a too short riser and lots of leaks and no chimney. It boils my kettle pretty quickly and doesn't use a lot of wood, but it isn't good enough. I'm ready to whip out the clay and sand and create a 100 mm (4 inch) DSR2. Since this appliance lives outside under a tarp, and gets regular attention from the local black bears who wish I would leave some scraps, I'm going to use the bricks I've been moving around for years, none of that fancy fiber board type stuff for me. I have a nice collection of both insulated and hard firebricks. I have a glass piece I salvaged from a dead single burner induction plate that I hope to use right over the riser. I hope that it's thermal expansion is minimal! I've done a few pieces of casted parts over the years, and still have some of the refractory stuff. I've never done it right, as in shaking it for more than a few minutes to get the bubbles out, but I've been using it without issues for a couple years. I need to make the lid for the bottom box since my bricks are not wide enough and the lid for the top box. I'll have to cast a stumbler too. This is going to be the open system, no doors or P channels. I have a couple of questions for the hive mind... 1. The exit port on the DSR2 is about 42 x 143 mm, at least that is what I measured. Does it have to be a rectangle? Has anyone tried making it a square? I've read through Peter's incredible notes creating it, but I don't recall if he ever tested a square exit port. I'm wondering how that would affect the stumbler's shape and function too. I think I know the exit port should be 5% bigger than the riser cross sectional area. 2. The Permies post for one of the earlier versions of the batch box said the surface temp of the glass stovetop in one area was 1000 F, or maybe it was C, in either case, HOT. I'm guessing the hot spot would be localized right over the riser, but maybe it is the exit port, or by the stumbler. Does anyone know? If the hot spot is the exit port, would putting a pot over the exit port kill the draft? I'm talking about leaving enough space for the gas to get out under the pot. It wouldn't have a chimney in this case. 3. I have stove pipe, but am not sure what the best way is to make the chimney. The chimney will have to be easily removed since it won't fit under the tarp and I'm sure the bears would love to knock it around. I would like to harvest some of the hot gas during maple syrup time, (it got down to -7.8 C or 18 F this past spring) but most of the year I don't really need to store the heat. So, do I put the stove pipe right over the exit port? Is it criminal to use a 6 inch stove pipe on a 4 inch system? It will only be about 4 feet long. I recall the pictures from the Montana build that used a crazy big chimney thing, so maybe I'll be okay. Will the exit temps be too hot for a stove pipe? I have plenty of sticks, mostly maple, fir and hemlock. I have paper birch galore, so starting a blaze is too easy. I put this post here since I think the top surface of the DSR2 will make a great platform for my chafing pans maple sap evaporator. I was thinking of using the stainless steel chafing pan as the lid for 3/4 of the top box, but was wondering if that would keep the top box from getting hot enough for an efficient burn. I imagine the metal would make interesting noises as it expanded and contracted when I added cold sap. My do it yourself flue gas testing project has been neglected for a long time. I tried to get universities interested in doing the testing, but no one took me up on it. If anyone wants to fool around with a homemade, unproven Testo like device, feel free to check out... docs.google.com/document/d/1UaVK4XO46G51LYe6Pd3v5tCrHtLteAPdmCEX-vHgfBk/edit?usp=sharing It requires a few sensors that are pretty cheap and a arduino, which a lot of libraries will lend you for free. It is in no way ready for prime time, but once I get my new stove made, I'll resurrect it. Thanks again for everybody who posts to this forum. I love seeing the incredible finished projects and watching the building process. Hallinen |
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Post by peterberg on Jun 18, 2020 7:25:48 GMT -8
Hi Hallinen, I think you are mixing up the DSR1 and DSR2 core configurations. The thoroughly tested version is the DSR2 which incidentally didn't sport a glass top. Instead, the end results were obtained with a refractory top and a bell over and around it in the shape of two barrels. I'll try to answer your questions, geared to what you want to do with it. 1. The exit port on the DSR2 is about 42 x 143 mm, at least that is what I measured. Does it have to be a rectangle? Has anyone tried making it a square? I've read through Peter's incredible notes creating it, but I don't recall if he ever tested a square exit port. I'm wondering how that would affect the stumbler's shape and function too. I think I know the exit port should be 5% bigger than the riser cross sectional area. In order to obtain results comparable to mine the end port do need to be rectangular. As wide as the top box, I might add. The effect of having a glass top like the DSR1 is an interesting idea though. And I spotted a mistake: the end port of the DSR2 isn't 5% larger than its riser's csa but as its riser port instead. Big difference! 2.The Permies post for one of the earlier versions of the batch box said the surface temp of the glass stovetop in one area was 1000 F, or maybe it was C, in either case, HOT. I'm guessing the hot spot would be localized right over the riser, but maybe it is the exit port, or by the stumbler. Does anyone know? If the hot spot is the exit port, would putting a pot over the exit port kill the draft? I'm talking about leaving enough space for the gas to get out under the pot. It wouldn't have a chimney in this case. The Montana version was the DSR1, no riser at all. Very prone to overfuelling by the way. The exit port of that one was larger than the riser port, even a little bit more so than the riser as I recall correctly. How the shape and size of the end port could influence the gas velocity in the riser port was found out in early 2019. The same goes for the stumbler, which was absent in the DSR1. 3. I have stove pipe, but am not sure what the best way is to make the chimney. The chimney will have to be easily removed since it won't fit under the tarp and I'm sure the bears would love to knock it around. I would like to harvest some of the hot gas during maple syrup time, (it got down to -7.8 C or 18 F this past spring) but most of the year I don't really need to store the heat. So, do I put the stove pipe right over the exit port? Is it criminal to use a 6 inch stove pipe on a 4 inch system? It will only be about 4 feet long. I recall the pictures from the Montana build that used a crazy big chimney thing, so maybe I'll be okay. Will the exit temps be too hot for a stove pipe? A stove pipe just over the exit port is tried and works, I guess an oversized pipe would work as well. The exit temps will melt aluminum but a steel pipe would be OK. Almost certainly burn off the zinc layer, seen as discolouring of the rectangle pipe in the Montana build. Best not to use steel as the top of the core, I'd recommend ceramic glass instead. Just over the riser would be the hottest spot. |
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Post by hallinen on Jun 18, 2020 9:06:15 GMT -8
Thank you Peterberg. I was getting DSR1 and DSR2 mixed up. I'll go ahead and cast the box tops and try the ceramic glass over the riser hot spot. If it doesn't work that great as a cook stove, it will inspire me to finally build my sauna and use it in there.
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