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Post by Vortex on Nov 25, 2021 16:09:14 GMT -8
What ISA should be for 150 mm vortex stove? Hi Hof, because of space limitations I have 3.2m2 ISA on my stove, the exhaust temperature peaks at around 150C so I would think the maximum for a 6" / 150mm would be about 5m2. |
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Post by hof on Nov 26, 2021 1:50:53 GMT -8
What ISA should be for 150 mm vortex stove? Hi Hof, because of space limitations I have 3.2m2 ISA on my stove, the exhaust temperature peaks at around 150C so I would think the maximum for a 6" / 150mm would be about 5m2. Thank you! |
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Post by Vortex on Nov 27, 2021 5:54:39 GMT -8
The experiments with high surface area to volume ratio in the top chamber, showed that at the highest levels it creates a very stable low CO. burn, but the fire usually runs out of O2 at some point and then the CO. goes vertical. This happens because the high surface area drag leads to a much slower gas flow, which means less air over the fire. Expanding the air supply only helps up to a point, as the gas flow has slowed to a level where a larger air supply has almost no effect because it cant make use of it. This is how that looks on a typical graph:  By widening the top chamber exit up to 100% CSA, reducing the surface area to volume ratio back down to how I had it in February (page 56), and increasing the primary air supply up to 30% CSA, I found a combination that's very stable and reliable. It holds the vortex nicely in the rear of the afterburner and resists overfueling or thermal runaway. It raises the 02 level across the burn slightly, so it rarely ever drops below the critical 7% level, even with a lot of small fuel. I've also made the afterburner 1" deeper and the front and rear sides of the port are sloped towards the rear. The rear of the afterburner is about 1/4" back from the rear edge of the port. The sunken area in front of the top chamber exit is there to enlarge it back up to 1 CSA without having to make a long thin exit which would be too far forward, the dimensions of the 2 sides of the sunken area are 65mm x 130 x 147mm, and drop down 40mm. The exit is 120 high x 147mm wide. I haven't tried it without the small triangular piece yet. Vermiculite board smooth side out seems to work best:  Top Chamber removed looking down at the port from above:  Typical run with full primary air through the whole burn:  If anyone can help me make a few changes to the sketchup file I would be grateful, thanks  |
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Post by hof on Nov 27, 2021 14:12:47 GMT -8
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Post by Vortex on Nov 27, 2021 15:24:10 GMT -8
I'm not sure what your question is. If you're asking if I think those stoves will work, then I cant see any reason why not.
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tferr
Junior Member
Posts: 69
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Post by tferr on Nov 27, 2021 16:16:33 GMT -8
Hey Trev, in the vortex4 skp are the afterburner wall sections made of ceramic fiber board. if not ...do you see any reason not to use that
I am planning on pouring my firebox tomorrow ...mizzou cast plus
Thanks as always Tom
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Post by Vortex on Nov 28, 2021 2:29:29 GMT -8
The sides of the afterburner in my stove are Insulating Fire Brick, (they are very light and chalky, used for insulating kilns) roof is vermiculite board but you could also use it for the sides. I wouldn't use ceramic fiber board at all if you can avoid it.
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tferr
Junior Member
Posts: 69
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Post by tferr on Nov 28, 2021 4:46:03 GMT -8
The sides of the afterburner in my stove are Insulating Fire Brick, (they are very light and chalky, used for insulating kilns) roof is vermiculite board but you could also use it for the sides. I wouldn't use ceramic fiber board at all if you can avoid it.Thanks ....is that because of the health implications |
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Post by Vortex on Nov 28, 2021 7:41:46 GMT -8
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tferr
Junior Member
Posts: 69
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Post by tferr on Nov 28, 2021 15:35:27 GMT -8
Well I wont lie...the chemistry is over my head....however the conversation was entertaining
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Post by marcios on Nov 29, 2021 1:01:58 GMT -8
Trev, how could I make the exit port using a single 40 or 50mm shelf?
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Post by Vortex on Nov 29, 2021 3:10:27 GMT -8
No way to make it in one piece, you'd need to cut it. If you cast it in one piece it will almost certainly crack down the middle, so best to make it in 2 halves. A 4 inch hand grinder will cut it with a masonry disk. If you don't have access to one then you can take the slab to a masons shop and they'll cut it on a wet saw for you.  That drawing was for a 6" /150mm system. The pieces sat on top of the side and back walls which were 2" / 50mm thick. You'd have to adapt it to your needs but it gives you the basic idea.  |
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tferr
Junior Member
Posts: 69
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Post by tferr on Nov 29, 2021 3:17:31 GMT -8
Bummer I just cast mine in one piece
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Post by Vortex on Nov 29, 2021 3:25:38 GMT -8
You can just cut the slab down the middle as above, or you can just let it crack, so long as the front is supported it wont go any where. The front of mine is supported on the door frame.
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tferr
Junior Member
Posts: 69
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Post by tferr on Nov 29, 2021 3:50:23 GMT -8
yeah I remember reading that.Ill cut it today. Do you think cfb is an issue if it is not in contact with any flame. I was thinking of usingit onthe backside of the stove between the outer steel and the brick
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