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Post by rakettimuurari on Nov 13, 2018 1:12:25 GMT -8
Nice idea with J-tube... got me thinking some possibilities. Yes; first it should be definitely made sure that J- tube is working properly by itself. For my J- tube the type (or even quality) of the wood has never been an issue - it eats everything when warmed up. Only the amount of fly ash is larger with birch and with spruce too. It is 6" system and I usually clean out the fly ash on every third burn or so... much of the ash is probably flying through the riser and ending in to the bottom of the barrel bell. However my cooking plate on top has an uneven bottom and i suspect it makes some of the ash fall back in to the riser. It should be made sure that the rocks wont choke the system CSA on top of the riser as this will probably directly impede the rocket operation. Maybe a certain kind of flow divider guiding the gas stream evenly to many directions through the rocks? I would make the total CSA of the divider bit larger than the system CSA to accommodate the drag... Myself I would go with DSR2 kind of setup to experiment... DSR2 -thread
-Antti-
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Post by rakettimuurari on Nov 10, 2018 2:16:00 GMT -8
Jonas, Sounds really ambitious, I must admit... Would u think some kind of metal frame/ stand would be necessary for supporting the rocks? Also some kind of chimney is usually quite crucial for proper rocket action; gets quite bulky for transport very soon. That said, many nordic army tents often have stoves which come with attachable chimney pipe, divided in parts of some 50cm each; u can build chimney in 20 seconds with those; they're also light weight... they should be easy to DIY too... According my tinkering with normal sauna stoves, I would say there cannot be any kind of insulation or gap (ceramic fiber board?) between the rocks and fire path (usually it is some 5mm of steel) - and I am now talking about the sauna with constant ongoing fire on it also during the sauna session ---> chimney necessary. Another option would be to lead the fire and gases directly through the rocks for a proper time in closed system, which is then finally opened for throwing the water on the rocks when they are enough heated and fire is gone. This is the way I would go. U also would like to have enough space for big enough rocks as the small ones would cool down by the first throw of water. Now tucking some largeish rocks (size of two fists at least) in to the top box of DSR would definitely have some kind of effect to "flow pattern" etc. This should be tested If u find one, I would be really interested also! Greetings from Finland, Antti
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Post by rakettimuurari on Oct 9, 2018 2:51:44 GMT -8
just a thought, will painting the steel with mud prolong its life? I've been wondering that too... I would figure that larger expansion of steel in heat would flake that clay off; should try though!
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Post by rakettimuurari on Sept 16, 2018 23:34:54 GMT -8
Hello scottiniowa, Cant wait to see pics about your finished build later. You seem to have nice opportunity for the metal part of the work yourself, which I am sure many of us dream only Just few thoughts about the bottom insulation; I have tried three different options of bottom insulation in my builds (locations is near Tampere, Finland); they are sure all very different machines but nevertheless: 1) RMH in my sauna dressing room is sitting on a 10cm/ 4 inch concrete slab - only insulation is thick layer of tinfoil cardboard between the slab and firetunnel bottom. No problems in operation but it will certainly leak some of the accumulated heat in to the slab below, which in my case is useless waste as i have the bell built for gathering the heat. 2) BBR in my main house living room stands on 5 inch strengthened concrete slab, which again is sitting on the 2 inch vermiculite-concrete mixed slab. Bottom of all that is the house foundation of large rocks and sand. In that case again bottom insulation (wool) effect would be quite negligible in my opinion due the bell system as chimney opening is some 3 inches from floor. Vermiculite in very bottom is supposed to help to insulate from ground coldness - I see it is more important to ensure that capillary connection from ground in to the heater structure is cut (with material water cant penetrate) somewhere below the heater to ensure that heater does not suck in the humidity from the ground... 3) Ancient Aryan Sauna stowe (name is a joke) in my sauna. There for the first time I istalled wool insulation below the heater's firebrick firebox (1,5 inch of white superwool). The whole thing is sitting on a thick concrete floor (whole hot room is), which gets really cold during the winter here in Finland as I have no floor heating. Because of that I thought of using the wool... This is the lightest of my heaters but firebox accumulates operating temp very fast. All in all I would myself from now on always use wool heat insulation on bottom whatever the case, but still I would put a higher priority for insulation against humidity from the ground if there is any capillary connection between the heater and the ground (earth ). Everything - of course - is affected by the local circumstances certainly.
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Post by rakettimuurari on Apr 28, 2018 10:57:51 GMT -8
Little information to answer. I was only on Elbrus (5642 m) and Altai, Carpathian mountains every spring for 11 years... I guessed Elbrus; In previous picture that is me on top of Elbrus in June 2007 - I thought u might recognize it. We made approaching trek from north-west; some 100km and one week from direction of Petigorsk. Climbed north side with 4 man group; last camp was at 4800m... Such a beautiful piece of our earth!
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Post by rakettimuurari on Apr 27, 2018 7:04:18 GMT -8
A very respectable looking monument! Dark bricks very nice too. Congrats!
How much the final ISA was stretched by the way?
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Post by rakettimuurari on Apr 27, 2018 4:17:17 GMT -8
Thank you Sirs! I went through those resources; interesting. Ramunas has done quite much stuff actually... The notion of self regulating secondary air is interesting indeed! My experiments with less primary more secondary were not successful. Choking the primary halts the whole stove and afterburner. Probably the system CSA and draft is just too small for implementing it. Top chamber is also not likely to get high enough temps for slowed and secondary stressed combustion. I would like to build something bigger and more "masonryish" with aryanka workings though. Maybe later. As for now I am satisfied with the operation of my sauna stove. I will mod it further when enough spalling has taken place in metal areas. Serg: by the way; which mountain? do u happen to know this place ?
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Post by rakettimuurari on Apr 23, 2018 23:18:47 GMT -8
pigbuttons: Thanks! One more actual benefit towards wood savings has also been the fact, that new mass of bricks accumulates so much heat during the heating cycle, that there is absolutely no need to dry the sauna with any other means... like usually we have added few wood blocks to firebox when leaving sauna. Drying is important aspect in keeping the otherwise unheated structure intact from humidity damage in finnish true 4 seasons weather... I also have 160mm Rocket Mass Heater in dressing room for winter.
vortex, serg: Yes, I went back to check the double shoebox again; it is very similar. I just never dared to think exposing the metal stove to rocket temps... Already with this system I am relatively sure something will be soon destroyed by heat, not to mention the scenario where I would implement Peter's system's even better combustion. Secondary air floor channel also adds complexity and vulnerability.
As for now I smoothed an old chimney damper of cast iron (20x30cm) with angle grinder and fixed it on the ceiling of secondary chamber at the point where the flame jet hits making it now 5mm of cast iron + ca. 3mm of steel. I also made some additional sealing around the nozzle so no gas will stream from any other gaps. Secondary air can be still given by just opening the upper chamber door some millimeter if experiment are needed. I was watching Matt's pre-port secondary air videos some time ago and I am interested to experiment how would choking the primary air/ adding more secondary air configuration work. Slowing the burning process but still keeping the secondary chamber hot is interesting option for this sauna stove...
What do you guys see going on in this video? Maybe it demands insulated top chamber to get high enough temps? There seem to be not too much secondary air either...?
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Post by rakettimuurari on Apr 22, 2018 22:33:59 GMT -8
rakettimuurari How and how much air is supplied to the upper chamber? If you use the furnace Peter, but instead of riser upper chamber, it simplifies the supply of air and mixing, turbulence. Upper chamber only for afterburning and heat recovery. Hello Serg, There is no secondary air supply at all as I wanted as simple configuration as possible. Also I have understood that those Russian versions neither have it although there was some discussion about it in forums in case the secondary chamber has a door... Originally I was thinking to use the ash box hatch/ intake air of original stove for secondary air but with that it behaved worse. The way it is installed now (ash box sealed) it will burn all the excess air from primary chamber in the secondary I think... so there is no extra air to cool it down. more than that the junction between the stove and primary chamber is not 100% air tight so really small amounts of air is getting inside just below the port. *If you use the furnace Peter, but instead of riser upper chamber, it simplifies the supply of air and mixing, turbulence. Upper chamber only for afterburning and heat recovery.
-can you elaborate what you mean by this?
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Post by rakettimuurari on Apr 21, 2018 23:04:03 GMT -8
Oh wait, which way around is your port, front to back or side to side - It's difficult to tell from your pictures? I presumed it was front to back, so if it's not then that would explain why it looks too wide to me. Yes, you could say it is side to side - 9 cm wide, 6 cm deep from front to back; this is very close to 70% of CSA as stove's chimney connector pipe is 10 cm/ 4 inch wide inside. I wanted to place the port side to side and little behind as the exits (2) from secondary chamber are in the ceiling in the front, just behind the glass door. That will make the hot gases stay in the chamber just bit longer. Last night I narrowed the port to near 60% CSA and also built the port to reach 6,6 cm higher in the secondary chamber. Jet was visibly weaker and sauna was less efficient. So basically it seems that the first configuration with 70% CSA port happened to be optimal. I still need to try it with the mentioned two modifications applied separately... I think I will end up doing this... just need to figure out the holder system configuration as i don't have welding tools. When the bottom of the stove gives up finally one day, I am planning to make replacement plate between the chambers with refractory mass. Then it is easy to lower the upper chamber and also to try front to back port.
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Post by rakettimuurari on Apr 21, 2018 5:12:13 GMT -8
Nice work, rakettimuurari! From the short video it looks like the port is a little wide and the top box a little high. Have you experimented with any different configurations yet? Thx vortex, for yourself too Tonight is another saunanight (sauna frequency somehow got increased ...) and before I saw your post I was actually planning to choke the port to be even bit smaller by just sliding the brick; we'll see how it affects. I have also considered to increase the height of firebrick nozzle/ port depth; now it is around 15cm in total. It would be easier than cutting the bottom of the sauna stove away... I understood in Russian forum that port can actually be deeper without adverse effects? I have understood that they got higher temps by reducing the distance between the port and upper chamber ceiling like you suggested too... although Google translator is very poetic and weird with Russian at times On the other hand the higher secondary chamber possibly decreases the thermal stress in the chamber ceiling providing longer operating life? Probably the jet will be already enhanced by choking the port but other than that i am cautious as there is now more than enough power + burn is all out smokeless... At first full burn I was sure that stove will melt by the sound of the burn; like jet plane taking off. Do you think the "flamethrower" stream should be even more intense? ..and; have you found the system size - port size ratio from anywhere for Aryanka?? I was not able to find it... so i just tried to figure it out from some venturi- effect references... ***
...if I was older and wiser I would install right at this point a 2,5 cm firebrick plate free floating in to the secondary chamber ceiling, at the place where the flame jet collides... Russian proverb violated by google translator: "It is not very playful piano"
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Post by rakettimuurari on Apr 20, 2018 22:49:46 GMT -8
I'd like to share my 2day- project... This started from the idea to prolong the firebox of the existing Skamet 110 sauna- stove with firebricks in order to accommodate longer cordwood. Original stove: It is a small stove for 5-12M 2 saunas with 115mm cross sectioned pipe. When planning the thing I happened to remember what docbb had here or vortex and serg247 brought up here. After going through most of the Russian forum with translator mentioned in the first link by docbb, I decided to try this double chambered furnace idea in my sauna. I knew that stove was wasting some of its power to warm the sky as I got the secondary burn in the chimney all the way up to damper slits (2m from floor) if opened the damper entirely. So idea of having longer firebox + more controlled secondary burn was tempting. Quick drawing was made for 38 firebricks, adding some 80kg of mass to be heated (not optimal in sauna). New primary chamber has approx. same volume as secondary; around 25 liters. Firebox narrow and high as used in batch rocket to improve burn. Dry laying... Cutting the port. Went for 80% of CSA which can be tuned with firebricks to be smaller... went instantly with tuning for trusty 70% which worked. Base ready for the stove. Cast iron slabs are there to give more durability for primary burn chamber ceiling. Super wool was added under them. Door is from the old cooking stove. Whole set up standing... Firebrick adjustable "nozzle" in new secondary burn chamber, which is in actual sauna stove. And what can I say... It works like charm! Sauna heated in same time as before, stones stay hotter and vapour of thrown water is stronger than before + 1/4 to 1/3 less wood is consumed. Top end of the chimney does not give smoke and not even steam - there are only transparent heat vibrations visible -> burns quite clean. Probably I will have to enstrengthen the ceiling of the secondary chamber at some point...
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Post by rakettimuurari on Mar 21, 2018 8:44:22 GMT -8
I would love to see your design if you have any of it digitized. I've been looking to borrow some of the contraflow designs into my build this summer. -Gadget Hello Gadget, U can find my plan here: donkey32.proboards.com/thread/2308/brick-sidewinder-riser-baking-ovenIt is more of a batchbox than contraflow, but I used some structural conventions common with cf's. Works 110%. Has kept me warm during this coldest winter for decades. Happy planning!
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Post by rakettimuurari on Jan 5, 2018 2:10:09 GMT -8
Hi Yasin, It is typically a second bell positioned below the first one, à la Groum Grzimailo. In his book, he explains how hot gases coming from a first upon bell into a second below bell or gases coming from the upper part of a bell divide in equal currents while cooling as they go down to the bottom of the bell. His mathematical explanation : heatkit.com/docs/advanced/Pages%20from%20TheFlowOfGasesInFurnaces.pdfModern Pottery kilns were made this way at the end of the era of wood kilns, following Groum Grzimailo works. Bricks or potteries are columns and narrow ways between them are ways for gases. I must find drawings... Excellent piece of info! My thanks!
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Post by rakettimuurari on Dec 22, 2017 11:56:26 GMT -8
thanks for the illustration. Bell does the job. If you're a pro and want 5-10% more heat, play with damper Yeah... for me it would be more exotic/ pro to be without a damper . I just harvest the extra % of heat by doing it like before in old fashion way. All in all I consider the bell system to be an excellent concept!
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