[Stoves] Correcting a misconception that approaches myth status

Ronal W. Larson rongretlarson at comcast.net
Wed Dec 17 15:32:54 CST 2014


Paul and list + 3 ccs

see below
On Dec 17, 2014, at 8:17 AM, Paul Anderson <psanders at ilstu.edu> wrote:

> Ron and all,
> 
> I echo and re-double your thanks to all who have saved those earliest messages of the Stoves Listserv.   AND send thanks to those (Ron included) who wrote those messages in 1996.   (even though a strange Date of Aug 31, 2004 keeps showing in the headers?)

	[RWL:   The thanks for saving should presumably go to Tom Miles (paying all the bills for this list activity) and Erin Rasmussen.  The 2004 date is just the day on which the old material (I thought had been permanently lost) found its way to the present site.  There still are some missing messages on stoves (specifically mostly TLUD as the topic) that were on a third server before these from Feb ’96.

> 
> About the computer modeling of TLUDs, there was a large grant given to a group at Colorado State Univ, and they are expected (according to Dean) to be part of the presentations at ETHOS 2015 (6 weeks from now!!). 

	[RWL:  Yes.  I have been talking to a CSU ME PhD candidate (Jessica Tryner) who has been doing some fine lab work under the same contract.  There is a recent paper by she and two others [Bryan D. Willson, Anthony J. Marchese]   (http://www.sciencedirect.com/science/article/pii/S0973082614000817;  behind a paywall).  I have decided to not bother the CSU theory team until hearing them in a month at the ETHOS meeting.  I get the sense that the theoretical side may not go as far as I feel possible and hope for.  Jessica’s work and paper covers five different stoves.  Paper title:    The effects of fuel type and stove design on emissions and efficiency of natural-draft semi-gasifier biomass cookstoves’


Ron

 
>   
> 
> 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 12/16/2014 11:30 PM, Ronal W. Larson wrote:
>> Dean, cc Paul, Crispin, List
>> 
>>  1.  I can support your proposal on summarizing TLUD experimental history.  But just as valuable would be a computer modelling RFP (presumably from GACC, so I add Ranyee as a new cc).  There are hundreds of biomass combustion/gasification/pyrolysis folk out there who could bring highly sophisticated computer programs to bear right away.  Finally the stove community has the money to do this.   A TLUD has to be much easier to computer-simulate than any other stove.
>> 
>>  2.  Some of the recent conversations have mentioned BLDD stoves - of which I know not one recent example on the cooking side (which this list is mostly about).  To check that, I did a search on several approaches that grew out of the excellent Dutch work on BLDD stoves - and in particular by a Dutch transplant to Australia - Dr. Pet Verhaart.  I was amazed to find that Tom Miles or daughter Erin Rasmussen must have found the early records of this list beginning in 1996, which I thought had been lost (see http://www.bioenergylists.org/newsgroup-archive/stoves/1996-February.htm for the first month history).   If anyone knows some earlier communications on TLUDs on a different (but still Tom Miles) list, I hope they can report where they are.
>> 
>>  3.   I suggest to Dean that this above source should be part of the “progress history.  In that first month, we had contributions from Mark Bryden and Kirk Smith  (but not on TLUDs), which I had not recalled.  Heavy participation in that first month from Piet’s colleagues (Prasad, Moerman, etc) as well from Eindhoeven - especially on BLDD cook stoves.   
>> 
>>  4.  I have mentioned the name Tom Duke several times on this list - an Iowa farmer - who did several experiments (and one of the few lauding char-making stoves in that first month) that I have not seen repeated since - claiming good results even with zero-cost TLUDs.   I’m sorry we have lost contact with Tom.   
>> 
>>  5.   I hope to read March 1996 in the near future;  by the end of February, we had not yet found agreement that TLUDs would work.
>> 
>> Thanks to Tom or Erin for finding this historical resource.  And to those discussing BLDD stoves - which caused me to find what I thought had been lost.
>> 
>> Ron
>> 
>> 
>> On Dec 16, 2014, at 2:00 PM, Dean Still <deankstill at gmail.com> wrote:
>> 
>>> Dear Paul and Crispin,
>>> 
>>> My hope is that someone will do the experiments to detail how the work with TLUDs, etc has resulted in progress and publish the results in a peer reviewed journal. It might take a while but it's a job worth doing. Maybe find an interested student or professor to instruct?
>>> 
>>> Best,
>>> 
>>> Dean
>>> 
>>> On Tue, Dec 16, 2014 at 7:42 AM, Paul Anderson <psanders at ilstu.edu> wrote:
>>> Stovers,
>>> 
>>> This is about Crispin's story and showing slow progress, but it is progress. 
>>> 
>>> On 12/16/2014 12:51 AM, Crispin Pemberton-Pigott wrote:
>>>>  
>>>> There are dozens of ways to make a stove work improperly. Paul and I have tried all of them, I think. Paul told me that a TLUD fuelled with wood could not be refuelled. We were on the back patio of my home in Ezulwini Valley in Swaziland and he went off to do something, leaving a small TLUD can-stove running,. I fed in some wood vertically and it worked just fine. I continued to do so and it continued to run long after it should have gone out. Thus I proved to myself (and Paul) that TLUD’s can be refuelled but not too much at a time. OK, that was valuable and contradicted received wisdom. 
>>>> 
>>> His story is correct.   I remember it well (now that I have been reminded).   But it also tells us something about the progression of our science.   
>>> 
>>> Back then, the importance of the MPF (Migratory Pyrolytic Front) had not been realized.   What Crispin did then in 2002 was what BP-Oorja, Biolite and Philips and others did years later.   They were all trickle feeding additional fuel into the TLUD well above the pyrolytic zone.   Heat from below was (and still is, if you do it) sufficient to pyrolyze the new fuel by heat WITHOUT the small flames of the pyrolytic front at that fuel.   The char can be fine, but probably a little different (not made at the higher temperatures of the MPF).  
>>> 
>>> And when the MPF reached the bottom, and with new fuel placed on top of the char (not into the hot zone), the unit switched over to operating with Bottom Burning (BB) as a rather normal UpDraft gasifier.   And that leads to higher temperatures in the bottom (air coming onto charcoal) and the need for the different materials (cast iron, ceramics, special metals) to protect that hot zone.
>>> 
>>> As I have written in "Micro-gasification Terminology: An Instructional Summary of MG", available at my website.   See:  http://www.drtlud.com/wp-content/uploads/2013/11/micro-gasification-terminology-14nov2013.pdf  
>>>> Therefore, there are actually two types of TLUD (device name) gasifiers, one being TLUD-MPF and the other being TLUD-BB. The two types are quite distinctive in operation, and deserve separate recognition and study. The common usage of the “TLUD” name today means more than the TL of “Top-Lit” can signify. ...... snip ...  In essence, TLUD is a name for the small updraft gasifier processes/stoves and is not a description of what process (MPF or BB) is actually happening. However, we expect that in common usage, the TLUD name will designate TLUD-MPF, unless the UD-BB mode is specified.
>>> However, many people continue to ignore the transition from MPF to BB.   Back in 2002 I had no clue about this.   Now I consider it essential knowledge for understanding the variations within micro-gasification technology.   (Note that I wrote "micro-gasification technology" and not "TLUD technology.")
>>> 
>>> I repeat:  
>>>> 
>>>> However, we expect that in common usage, the TLUD name will designate TLUD-MPF, unless the UD-BB mode is specified.
>>> Of course I can only suggest and request.   People will do what they want to do, sometimes unfortunately.
>>> 
>>> 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
>>> 
>>> _______________________________________________
>>> 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/
>>> 
>>> 
>>> _______________________________________________
>>> 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/20141217/83b06b00/attachment.html>


More information about the Stoves mailing list