[Stoves] Baffle stove for serial TLUD operation Re: Dushanbe Stove
Paul Anderson
psanders at ilstu.edu
Sun Dec 6 12:32:38 CST 2015
Bill,
Thanks for your comments and your videos and for all your efforts. See
my comments in reply to Crispin (separate response).
Hugh McLaughlin also had a small TLUD (diagonal) with an auger feeding
fuel from the bottom. Not sufficient success to merit further work.
For a continuous operation when the budget allows for powered augers and
controls, I favor the AVUD system that is described in the Boiling Point
paper "Micro-gasification: What it is and why it works." (See Quick
Picks at my drtlud.com website). It is NOT a TLUD. But it is updraft
and continuous and scalable and makes great biochar if desired.
Interested people (with budget or with time plus skills plus workshop)
should contact me directly.
AVUD works in small sizes too, but the automation of the fuel feeding
and char extraction remains rather costly, and manual operation requires
a person's attention at least every 15 minutes or less. In small
sizes, the competition is from pellet-stove-headers.
Paul
Doc / Dr TLUD / Prof. Paul S. Anderson, PhD
Email: psanders at ilstu.edu
Skype: paultlud Phone: +1-309-452-7072
Website: www.drtlud.com
On 12/5/2015 6:47 PM, biocharFIRST . wrote:
> 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 <https://www/>.youtube.com/watch?v=ilUV5ya1xQM
> https://www <https://www/>.youtube.com/watch?v=xA0qugAsNzI
>
> On Sat, Dec 5, 2015 at 9:36 AM, Crispin Pemberton-Pigott
> <crispinpigott at outlook.com <mailto: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>
> <mailto:psanders at ilstu.edu> and Frank Shields
> <franke at cruzio.com> <mailto: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
>
>
> _______________________________________________
> Stoves mailing list
>
> to Send a Message to the list, use the email address
> stoves at lists.bioenergylists.org
> <mailto:stoves at lists.bioenergylists.org>
>
> to UNSUBSCRIBE or Change your List Settings use the web page
> http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org
>
> for more Biomass Cooking Stoves, News and Information see our web
> site:
> http://stoves.bioenergylists.org/
>
>
>
>
>
> --
> http://www.ithakajournal.com
>
>
> _______________________________________________
> Stoves mailing list
>
> to Send a Message to the list, use the email address
> stoves at lists.bioenergylists.org
>
> to UNSUBSCRIBE or Change your List Settings use the web page
> http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org
>
> for more Biomass Cooking Stoves, News and Information see our web site:
> http://stoves.bioenergylists.org/
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.bioenergylists.org/pipermail/stoves_lists.bioenergylists.org/attachments/20151206/a0007b64/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: image/png
Size: 316480 bytes
Desc: not available
URL: <http://lists.bioenergylists.org/pipermail/stoves_lists.bioenergylists.org/attachments/20151206/a0007b64/attachment.png>
More information about the Stoves
mailing list