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Post by Vortex on Jan 28, 2019 10:14:33 GMT -8
I tried some one sideders in rectangular chambers last summer, but they weren't very successful. This was the best of them: vimeo.com/313850912A round chamber should work better.
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Post by wiscojames on Jan 28, 2019 14:52:20 GMT -8
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Post by coisinger on Jan 29, 2019 5:19:52 GMT -8
Vortex, that is exactly my thoughts, but if you had a cylindrical chamber that flame would just wrap around the chamber. Nice light show and potentially a very vigorous mix of gases.
Might be worth a mockup. Sort of a 'dumb-bell' shape, where the port is centered on top of the batch box, angled to be tangent with the shoe box on top. Using batch box data, an 8" riser results in a 8" dia. Batch box x 24" deep. I understand the shoe box is aproximately 75% of the batch box size, so...6" dia on top.
Ok, I have to sketch this up...
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Post by pinhead on Jan 29, 2019 6:40:45 GMT -8
We musn't forget that peterberg tried using a single-vortex during testing of the original batch box and found that the double-rams' horn pattern was far superior in every aspect.
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Post by Vortex on Jan 29, 2019 8:15:36 GMT -8
That's true Pinhead, but that was in a 1 CSA riser. This is a very different setup more akin to the DSR, which also doesn't have a double vortex, but the chamber is cylindrical like a riser. I don't think that a single vortex can be dismissed altogether, just because it's been shown to not be as good in one configuration. Hopefully we can find out.
I look forward to seeing that sketchup Coisinger.
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Post by DCish on Jan 29, 2019 8:24:01 GMT -8
That's true Pinhead, but that was in a 1 CSA riser. This is a very different setup more akin to the DSR, which also doesn't have a double vortex, but the chamber is cylindrical like a riser. I don't think that a single vortex can be dismissed altogether, just because it's been shown to not be as good in one configuration. Hopefully we can find out. I look forward to seeing that sketchup Coisinger. Shameless plug here for a community-shared flue gas analyzer so when folks build and test ideas like this, they can be objectively compared to the existing body of work that has been contributed by folks like Peter and Matt. We hit this point so often where we speculate on how efficient this or that tweak may be, and many of these designs are actually built, but are rarely tested beyond the eye and nose due to a lack of testing equipment.
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Post by coastalrocketeer on Feb 5, 2019 12:06:36 GMT -8
The “aiming” of the port might benefit from it extending an inch and a half or so above the bottom deck... and the “obstruction” of the port to lateral motion toward center, sending it up, should enhance the creation of a horizontal vortex in the chamber.
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Post by Vortex on Feb 5, 2019 12:54:55 GMT -8
If I'm understanding your description correctly - you mean where the bottom of the vortices moving towards the center of the chamber collide laterally into the column of flame rising through the port? I suspect it would work to enhance the vortexes, but may also have the unintended consequence of reducing the mixing, as that seems to be where a large majority of it happens.
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Post by coastalrocketeer on Feb 6, 2019 23:35:57 GMT -8
Yes, I’m thinking of a couple of 45 degree wedges placed on either side above the port like this
/| |\ Maybe 1/3 of the height of the chamber, maybe less. Would be interesting to combine with an immediate downstream obstruction like in Peter’s latest experiment with two bricks blocking off the back of the chamber too and see if there is any synergystic effect between the two... I described this idea and my idea for a neoceram plate as an obstruction instead of the bricks, in that thread.
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Post by satamax on Feb 7, 2019 0:41:50 GMT -8
I think i kind of explained it here before.
Behind the port of a batch, there is a depression which occurs. And i think we could make a chamber with a narrower port behind. To raise the pressure. Ans increase the time burning gases spend in this chamber.
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Post by patamos on Feb 12, 2019 15:06:39 GMT -8
Hi Folks, Been ages since I've hung out here (or cyber-anywhere for that matter), but with 2 ft of snow on the ground in 24 hours I am finally finding time to catch up. Two thoughts: For best combo of insulation and durability in firebox I find IFBs mortared tight with furnace cement (Vesuvius Super 3000 or the like with sodium silicate and talc), and then a 1/8" parge coat holds up very well. The times when i have parged ceramic fibre board it tends to want to delaminate over time along with a bit of the skin of the board - especially if you lay up too thick. And man, we do NOT want to be breathing those fibres... Another board worth considering is calcium silicate, which many masonry heater builders are now using for firebox top decks with throats. Regarding the flue gas analyzer. If you check out MHA-net.org, Norbert Senf has explained how to build a low cost PM analyzer. From his/their experience, the correlation between testo gas analyzer and PM analyzer is strong, telling you pretty much the same thing. I've been meaning to build one, but man, these days i barely have time to scratch my butt.
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Post by patamos on Feb 12, 2019 15:19:57 GMT -8
Here is a starter article: heatkit.com/research/lopezq.htmI'll keep looking for the article showing a homemade version. I think it was someone in SOuth AMerica giving it a go...
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Post by patamos on Feb 12, 2019 15:20:41 GMT -8
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Post by patamos on Feb 12, 2019 19:22:33 GMT -8
The times when i have parged ceramic fibre board it tends to want to delaminate over time along with a bit of the skin of the board - especially if you lay up too thick. And man, we do NOT want to be breathing those fibres... Another board worth considering is calcium silicate, which many masonry heater builders are now using for firebox top decks with throats.
Hi Folks,
Well, having caught up on a few more threads... i see Trev mentioning how calcium silicate board is not holding up. I haven't tried it yet, but heard Norbert over at MHA mention he and a few others had begun using it because vermiculite board and CFB weren't holding up. Maybe they aren't reaching the same temps in the throat as Trev is. Or maybe there are different manufacturers offering various quality of product...
Also, re. ceramic fibre board, and Matt mentioning how well his has lasted... Maybe the best bet is to not coat it with anything. I know Morgan makes different densities to handle abrasion etc...
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Post by Vortex on Feb 13, 2019 3:05:01 GMT -8
Hey Pat, Welcome back. The calcium silicate board I have is rated to 1000*C/1830*F, but pops, cracks and splits if put in direct contact with flame. It's sold as backing insulation for kilns. The vermiculite board I have is rated at 1200*C/2190*F, that is OK in flame so long as it's in small pieces, big bits get expansion cracks and it falls apart. I have a piece of CFB as the roof of my afterburner chamber that has been subjected to the equivalent of a large gas torch for 1 to 3 hours a day for the last 3-1/2 months, and that shows no sign of degradation at all, but it gets no abrasion where it is. I have still yet to get hold of a kiln shelf to try out, have the ones you've used held up OK?
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