[Stoves] Baffle stove for serial TLUD operation Re: Dushanbe Stove

[biocharFIRST .]

Paul, Frank and all,

I am 100% behind your efforts to make biochar producing space heating more
practical.  If everyone who is presently using biomass for space heating
were to start producing biochar it would be an enormous increase in the
amount of biochar being produced.  And because of savings to be had by
producing biochar, which worth more than twice as much as the biomass, I
suspect that the use of biomass for space heating would skyrocket over the
amount currently being used.  This could make the expected results of COP21
seem insignificant in comparison.  So please count me in as a supporter if
there is anything I can do.

I can tell you  from my experience that I don't think  that a common wall
between two TLUD fuel chambers will work.  What will likely happen is that
the extra heat on one wall of the second chamber will cause the pyrolysis
front to channel down the warm side faster than the cool side.  It is also
conceivable the asymmetrical insulation value of the second chamber could
also cause the same problem in the first chamber.  And even worse, the
biochar on the insulated side will will start to burn before pyrolysis is
completed on the cool side, thereby raising the temperature enough that it
is likely the second chamber will be bottom lit.  My experience comes from
trying to vent the pyrolysis gas down the center of a 10 foot tall TLUD.
The pyrolysis front reached the bottom faster in the center. To solve the
problem we had to insulate the vent pipe.

The primary reason for my reply is to tell you about my experience with
trying to build a continuous feed TLUD about 5 years ago.  I stopped
working on the project because of a lack of any funding other than my SS
and the fact that I didn't have any of the machine shop equipment that
would have been necessary to proceed with the project in a reasonable time
frame.

Nevertheless, the youtube videos below, of an unfinished unit, show that I
did have some success and I am totally convinced that with a little backing
it can bed done. The idea was to feed a conical TLUD from the bottom and by
using sensors located at various locations on the cone to turn the feed
auger off and on to keep the pyrolysis front at the location in the cone
with the proper cross section to give you the desired heat output..

The first thing I learned is that I did not have the skills to hand build a
proper symmetrical cone so I settled on a pyramid shape which often gave
problems because the pecan shells I was using would not completely pyrolyze
in the corners.  I partly solved that problem by lining the feed tube and
elbow with UHMWP to reduce the friction.  The best solution  would be to
use a conventional horizontal auger and a vertical auger coupled together
with a right angle gear box.

The first thing I learned when I tried to operate the TLUD is that if you
locate the primary air input at the bottom of the reactor pyramid, is that
the moisture in the gas will migrate back and condense in the incoming fuel
and destabilize or shut the process down.  Even worse if you are using
pellet fuel, the pellets will expand into wet sawdust which stops up both
the auger and air flow.  The only solution to this is to feed the.primary
air into and through the air tight fuel hopper to the reactor.

The most suprising thing I learned is that because of the ease with which
the pyrolysis can be restarted, (see last video) is that there would be no
need to have a conical reactor.  A straight cylinder could be used and a
thermostat could stop or restart the process with a hot plate igniter or a
piolt light to restart the flame.

Wishing You the Best
Bill Knauss



https://www <https://www/>.youtube.com/watch?v=f4aAsDMDrDk
https://www.youtube.com/watch?v=ilUV5ya1xQM
https://www.youtube.com/watch?v=xA0qugAsNzI

On Sat, Dec 5, 2015 at 9:36 AM, Crispin Pemberton-Pigott <
crispinpigott at outlook.com> wrote:

> Dear Paul
>
>
>
> The idea was tried on a stove called Royal Ocean which is made in
> Ulaanbaatar. Briefly the history of the company is that a Mongolian guy
> went to Japan and learned how to make TLUD coal stoves there. When he got
> back to Ulaanbaatar he reproduced their two cylinder, one chimney stove. He
> also used the same name.
>
>
>
> It was brought for testing sometime in early 2011, in the final, or more
> final version. As constructed it was two separate ignitions but we
> (Lodoysamba and the guy and I) discussed at that time how to make one light
> the other when it burned to the bottom. It was to use paper where you have
> proposed gas. At that time, the TLUD approach was not fully accepted. The
> reason for this was the intermittent nature (which was bound to lead to
> problems) and the inevitable refuelling that would happen with a hot stove
> (which did and does).
>
>
>
> As to the merit of having it automatically ignite, I want to point to
> something. This does not address your idea of a continuous operation with
> dead cells being swapped when they are not in use, that is still possible.
> I am referring the division of the available fuel space into separate zones.
>
>
>
> Why do it? What does it offer that is an advantage over a single charge
> that is either a side draft or a TLUD? One should answer that and be
> convincing before complicating the process.  What the Royal Ocean stove did
> was to provide two separate TLUD chambers with a damper system that allowed
> the chimney to be connected to one or the other. It was a space heating and
> cooking stove.
>
>
>
> Having one light the other when it burned down allows the two to work in
> series, no doubt about that. It saves the operator removing a cassette and
> replacing it with a new one so it can burn longer. It was a good idea from
> that point of view. It was a bit complicated in that it had to have two
> sets of controls to get a good burn from two separate combustion ports.
>
>
>
> If I have a ‘given size’ of fuel loading space, I can’t see a good reason
> to divide it into smaller sections. One reason could be dropping the power
> to a low level for a longer time, right? Can that not be achieved without
> the complication? That is what I am wondering.
>
>
>
> In the end the Royal Ocean product had a single chamber. I suspect the
> power level was inadequate for the physical size, and the cost would have
> been substantially higher to make and manage two separate stoves inside a
> single housing. It was impressive to look at and nicely made, but all
> things considered, a larger single chamber worked better.
>
>
>
> A separate question: would the wall temperature of one chamber not
> overheat/pyrolyse the fuel in the adjacent chamber? Royal had a gap to
> prevent that, and they had the two separate with no gas connection between
> them because that would have changed the control over the air flow (over
> and under air).
>
>
>
> I looked around for a photo and only came up with this which is the single
> chamber version.
>
>
>
>
>
> I cannot prove anything about why he changed his approach from two
> chambers in series into one. Likely reasons are heating power and
> complexity.
>
>
>
> Regards
>
> Crispin
>
>
>
>
>
>
>
> Frank and all,
>
> Separate from the coal topic of Dushambe, so I changed the Subject line.
>
> About a Baffle stove:  On 12/4/2015 12:42 PM, Frank Shields wrote: [with
> my additions in  [... ] brackets]
>
> One idea [to attain a longer burn time] might be to add a night time
> insert. That would [from the side] look like a *IIIIIIII*
>
> with baffles that go almost to the base. The base has fuel [coal is being
> discussed, but could be other fuel types] spread across the bottom.  You
> lite [at the bottom] the one close to the door and that burns up quickly
> but it takes longer to ignite the second baffle and even longer for the
> third and so on……
>
> Frank, I like the idea of baffles of some type.   Probably done in some
> ways somewhere maybe long ago, but baffles are certainly not evident in
> currently discussed stoves and therefore your idea is a new innovation for
> us 21st Century stovers.
>
> I want to add a further variation for consideration.   It is based on TLUD
> principles.
>
> Consider a rectangular fuel chamber with several vertical baffles running
> across between the long side walls  (3 or 4 are sufficient for the concept,
> but could be more.)   First thought was to have square vertical boxes that
> are in a row, basically with one side shared by two squares.  (cylinders
> with obvious spaces is a variation to discuss later).   Call them B1, B2,
> etc for Box 1, Box 2......
>
> Ignite B1 at the top and let the MPF (Migratory Pyrolytic Front) do its
> job downward through that fuel, with burning of the created gases at the
> combustor level.   When the MPF reaches near the bottom, it encounters a
> hole on one side.  That hole is attached to a vertical pipe that is able to
> receive some (maybe 20%??) of the pyrolytic gases.  (the percentage could
> increase if the side hole is actually a vertical slit / hole that receives
> more gases as more of the slit is in the zone of the MPF.)
>
> The gases in the vertical pipe (call it an "ignition pipe") reach the top
> and are ignited by the existing flame in the combustor.   But those
> combusting gases are able to move upward into the combustor area of the
> adjoining box B2.   In that way flame is into the area of B2, and within a
> few minutes of time B2 has become Top Lit and begins to operate as a
> TLUD.   The process continues with B1 essentially shutting down (very
> little draft) and several ways of extinguishing the created charcoal by an
> operator or even "automatically".
>
> B2 ends and transitions to B3 in the same way.   If the burn-time of each
> Box is approximately one hour (easy to accomplish with height and with
> reasonable fuel like pellets), 8 boxes would operate the heater through the
> night.
>
> Quite literally, the boxes could be in a snake form or in a "6-pack" or 12
> pack or spiral arrangement and continue for 12 hours or even longer.   If
> the boxes were of different cross-sectional areas (different diameters),
> there could be different intensities of heat at different times.  That is,
> the five boxes B4 through B8 could have smaller X-section areas and give
> less heat in the hours from midnight to 5 AM, when B9 could have a larger
> fire.
>
> BTW, that B9 fire could be under a pot with bath water to be heated and
> ready at 6 AM when needed.
>
> What is described above is a system for CONTINUAL TLUD operation, as in a
> serial continual sequence.
>
> This system should work also for larger (such as barrel-size) TLUDs for
> making biochar AND with heat generation through a long cold night inside a
> greenhouse.
>
> Of course it can be improved.   And it can have electronic monitoring and
> the use of fans and blowers that can make the TLUDs respond in many ways.
> Such a system can have bells and whistles (figuratively and literally) such
> as alarms if temperatures go beyond user-specified highs and lows, or
> digital CO sensors with alarms about the ambient air inside a greenhouse.
>
> Should it be cylinders instead of square boxes?   One advantage of the
> cylinders is that the vertical ignition pipe can be placed in the natural
> area where the edges of cylinders are not touching 00000.   But shared
> walls cost less in materials, and the heat through the walls help pre-warm
> (and pre-dry) the fuel in the next box to be ignited.   But too much heat
> could cause premature ignition.  These are considerations for
> experimentation.
>
> So, as of 9:30 AM CST on Saturday 5 December 2015, with the presentation
> of this message to the publicly accessed Stoves and Biochar listservs, the
> above ideas are made public.   I believe that I and Frank have some
> intellectual property (IP) rights for one year after public disclosure.
> So if you want to try for patents, etc, you should include Frank and me.
> But instead, if your work is in the public domain, please feel free to get
> started.   We want you to be successful.   But we do want to be kept
> informed of activities and to encourage collaborative efforts.
>
> To move this concept / idea forward, we need some time and funding.   We
> hope that it is YOUR time and YOUR funds, or that you help us find outside
> funds that can pay for the time and materials.   Frank and I are both
> retired.   And we do not have the metalwork shops that should be involved
> with this work.   So we encourage your participation, and please keep us
> informed of your initial interest (which means tell us SOON), your initial
> activities, progress, results, and plans for taking it further.   Our email
> addresses are:    Paul Anderson <psanders at ilstu.edu> <psanders at ilstu.edu>
> and   Frank Shields <franke at cruzio.com> <franke at cruzio.com>
>
> We look forward to the discussion and to any activities.   This might all
> blow over and become nothing.   Or it might be a major step forward.
>
> Paul
>
>
>
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