[Stoves] World stove, fantasy draft, flame caps, TLOD, TFOD, DS

Kelpie Wilson kelpiew at gmail.com
Mon Apr 2 00:04:37 MDT 2018


Oh yeah, Ron, I am already thinking along those lines. Something like a
mashup between the Biochar Now afterburner-modified FAO kilns, the double
walled Ring of Fire Kiln and the Everything Nice stove. Got some
development funding in mind too.

Kelpie

On Sun, Apr 1, 2018 at 10:55 PM Ronal W. Larson <rongretlarson at comcast.net>
wrote:

> Kelpie and list;  Adding Nat Mulcahy
>
> 1.  Re your last sentence, my reading on Venturis says that big pressure
> differences can be generated.  The word “vacuum” means something here.
>
> 2.  This may be really off-the-wall, but I can (vaguely) see adapting the
> “TLOD” actions of World Stove to really large Kon-Tiki type systems.
> Couldn’t be exactly like Nat’s but I can imagine a double walled “Kon-Tiki”
> with a floor that has “holey” pipes, with a fan/blower system (might want
> more than one) a ways off that draws hot gases out of these “holey floor
> pipes” and then re-injects the hot gases now mixed with air back into the
> double wall kon tiki- to give controllable flames
>
> 3.   Advantages (possibly):
> a.  The kon tiki could be preloaded - perhaps right to the top (as is the
> Lucia and others)
> b.  There could be an optimum amount of added air - for premixing, but
> still able to form an oxygen - rejecting flame cap.
> c.   The hot N2 drawn down would create char.
> d.   There would never be glowing embers.  The fire would self extinguish
> when all the wood has been converted to char.(I think this is the biggest
> possible advantage)
> e.  You could add extra wood if desired at any time.
> f.  The duration and size of the flame could be controlled by the fan(s)
> speed(s).
> g.  The energy for the fan should be relatively small, and there are
> technologies to generate the needed fan power from the flame (for remote
> areas).
> h.  These probably better long and “narrow”
> i.  Could be totally separate fans for the added air,  or a Venturi effect
> might work here as well.
> j. A way-out possibility is that it could all work natural draft.
>
> Ron
>
>
>
>
> On Apr 1, 2018, at 5:58 PM, Kelpie Wilson <kelpiew at gmail.com> wrote:
>
> Hi friends,
> sorry but I get the email digest and cannot figure out how to reply to a
> subject thread, so I'll just start a new one.
>
> This is so interesting! I just got back from a workshop tour of Nebraska
> and Kansas, teaching flame cap pyrolysis for making biochar from invasive
> eastern red cedar. This use of waste biomass for biochar has been my focus
> in recent years, rather than stoves or TLUDs.
>
> So many times, I have seen flames from these kilns flowing upward and then
> turning back down. The flame tips have a downward hook at the top as
> something sucks the the air back down. These are Down Suckers, thank you
> Paul for that term!
>
> You can see a nice example of this pictured in my slides here:
>
> https://www.slideshare.net/kelpiew/flame-carbonizers-for-biochar-in-practice-and-theory
>
> Of course these flame cap kilns have no bottom air, but in the beginning
> stages of a burn, the air does flow down the sides and up the center of the
> fuel stack so they do operate in an updraft mode of sorts. So some of it is
> the air flow down the sides that is sucking the air from above and causing
> the flame tips to hook downward. However, in the later stages of the burn,
> we have completely filled in the kiln with hot glowing coals and air still
> comes from the top because the combustion must create a negative pressure
> to pull air in from the top. Which of these down-sucking affects might be
> taking place in a small stove?
>
> I also have to agree with Gordon, and with Bill Knauss, that there must be
> positive pressure from the wood gas as heat forces the volatiles out of the
> wood. That would be how the Everything Nice/World Stove works. Heat from
> the flame on top volatilizes gas down inside the stove. Pressurized gas
> flows up to the top of the fuel bed, feeding the flame, but some flows out
> through the side holes, gaining speed as it passes through the venturis,
> creating more negative pressure to draw more gas. In the annular space it
> pre-mixes with secondary air for better combustion. This pre-mixed gas then
> merges with the flame on top.
>
> It is not all about draft and buoyancy. Gas flows also occur from
> volatilization and oxidation.
>
> So the World Stove is definitely not a down-draft gasifier, but it is more
> than a TLUD. In fact, I have felt for awhile that a flame cap kiln is more
> like a retort than anything, since it is closed on the bottom. The flame
> itself closes the retort and acts as heat exchanger at the same time.
>
> The World Stove just acts like a self-heating retort with a flame cap, as
> pressurized syngas leaves and recirculates to the flame.
>
> I agree that I would really like to see someone evaluate Nat's claims
> about N-enriched char from his stove. That would be proof that down-sucking
> gas actually moves from the top through the fuel like a sweep gas. Not too
> sure that could actually happen. The venturi effect would have to be very
> strong.
>
> Kelpie
>
> --
>
> *Ms.Kelpie WilsonWilson Biochar Associates <http://www.wilsonbiochar.com/>*
> Email: kelpiew at gmail.com
> Oregon home office: 541-592-3083
> Mobile: 541-218-9890
> Skype: kelpie.wilson
>
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> --

*Ms.Kelpie WilsonWilson Biochar Associates <http://www.wilsonbiochar.com>*
Email: kelpiew at gmail.com
Oregon home office: 541-592-3083
Mobile: 541-218-9890
Skype: kelpie.wilson
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