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Post by DCish on Feb 1, 2019 12:19:20 GMT -8
What nasty byproducts are you thinking about are created at above 2300F ? Here is a great article on combustion (from flue gas analyzer manufacturer E Instruments). They talk about Nitrogen Oxides (NO and NO2) at a couple of spots, but mention "Thermal NOx" on page 12 as being formed at 2200F and above. So, oops, I need to correct myself from 2300 to 2200 on that other post. At one point Peter reported measuring peak sustained temperatures in rocket cores at around 1100C (~2012F), so it would appear that the stoves we are working with are just short of NOx formation temperatures.
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Post by gadget on Feb 1, 2019 12:57:53 GMT -8
What nasty byproducts are you thinking about are created at above 2300F ? Here is a great article on combustion (from flue gas analyzer manufacturer E Instruments). They talk about Nitrogen Oxides (NO and NO2) at a couple of spots, but mention "Thermal NOx" on page 12 as being formed at 2200F and above. So, oops, I need to correct myself from 2300 to 2200 on that other post. At one point Peter reported measuring peak sustained temperatures in rocket cores at around 1100C (~2012F), so it would appear that the stoves we are working with are just short of NOx formation temperatures. NOx forms at lower temperatures but the general consensus is 2800F is where any "significant" formation begins. Increase is non-linear and excess air enhances it. Basically increase is exponential after 2800F. Nice hockey stick curve. I don't think we need to worry cause we will never get there.
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Post by jdawgsplace on Feb 2, 2019 13:54:40 GMT -8
2800 degrees???!!! whoa...nah, i don't think that's my goal...
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graham
Junior Member
Posts: 74
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Post by graham on Feb 3, 2019 0:10:49 GMT -8
Hmm. Nitric oxide is more potent than Viagra ...
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Post by jdawgsplace on Feb 4, 2019 3:27:15 GMT -8
ok, i found some math but the image is over 6MB...so, i'm gonna try post a quote:
"...you need proper proportions of the heat riser to the burn chamber, as outlined in the drawing above. You want the diameter of your feed chamber to be 1.5-2 times as wide as the diameter of the chimney. This is so you can stuff half the feed chamber with wood, the section above the grate. The bottom section is for air flow, this large volume of air is one of the keys to a effective rocket stove. You will not achieve proper draw without this. You also need the heat riser, or the chimney to be at least twice the length of the length of the feed chamber. This allows the heat riser to function properly, acting as a strong vaccum once heated to draw air in through the air passage through the bottom to help fuel the fire, which spits out the top of the thing."
how accurate is this information?
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Post by DCish on Feb 4, 2019 9:54:26 GMT -8
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Post by peterberg on Feb 4, 2019 9:58:04 GMT -8
how accurate is this information? In my view it isn't. It mentions a grate and under air in order to "help fuel the fire, which spits out the top of the thing". There's a concensus catching on slowly that burning need to be complete before combustibles leaves the riser. Rocket heaters that are spitting fire routinely out of the riser won't burn clean, which has been measured quite a number of times. It is very spectacular but combustion isn't helped by this effect, rather the contrary. So keeping that in mind, spitting fire isn't a good thing and should be avoided. It might be this is a build that has some details in common with what we see as Rocket Mass Heaters, as thought up by Ianto Evans. A grate and under air aren't found in RMH's, air intake is top down in the feed tube. Also, according to the author of this, the feed chamber should be 1.5 to 2 times the chimney diameter. In effect, assuming the riser is 6" in diameter the 12" diameter will result in a csa that's 4 times as large. Just remember all written guideliness by people in the know say "keep the same csa throughout!" Is the author's name ppotty1 by any chance?
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Post by jdawgsplace on Feb 4, 2019 19:09:08 GMT -8
something i found on steemit...idk the author...sorry
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graham
Junior Member
Posts: 74
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Post by graham on Feb 4, 2019 23:11:49 GMT -8
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Post by jdawgsplace on Feb 5, 2019 2:07:18 GMT -8
yep...that's it
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