[Stoves] "Young-adult" TLUD research Re: List of woods for TLUDs?

Paul Anderson psanders at ilstu.edu
Sun Apr 30 22:46:07 CDT 2017


Ron,

A single controller (that does not allow for changing the ratio and 
amount of air to  PA and SA) is, by definition, unable to do that task 
that I suggested needs to be researched.

And there certainly are SINGLE controls since the Woodgas campstove had 
2 settings, and now Mimi-Moto has a dial with about 5 settings, but no 
change of ratio.

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 4/30/2017 5:13 PM, Ronal W. Larson wrote:
> Paul,  List and ccs:
>
> Well I haven’t heard a reason why my yesterday statement on only 
> needing a single controller (limiting fuels to the non-oily variety) 
> was incorrect.
>
> This is to hope we can have more discussion on this quite important 
> point.
>
> I am quite sure I saw a TLUD design a few years ago that used a single 
> air control.  Anyone able to help?
>
> I don’t know anything about Nathan Puffer’s work.
>
> Ron
>
>
>> On Apr 29, 2017, at 9:33 PM, Paul Anderson <psanders at ilstu.edu 
>> <mailto:psanders at ilstu.edu>> wrote:
>>
>> Ron,
>>
>> I disagree.   You wrote:
>>> preferring to use one controller for both is that the ratio of 
>>> primary to secondary should always be the same 
>> The point is that the ratio is NOT to always be the same.   Even the 
>> different packing of the fuel in to the TLUD can make primary air 
>> (PA) flow more easily, creating more gases and needing a change in 
>> secondary air (SA) to get optimal performance.
>>
>> Automobiles have sensors for all kinds of issues, with automated 
>> adjustments.   Just not practical yet for cookstoves that need to be 
>> inexpensive.  Bu who knows, someday solid biomass as initial fuel 
>> could be pyrolyzed and have the gases combusted in very controlled 
>> ways that would seem like Science Fiction if said today.  I believe 
>> that it will be justified for the woodgas/TLUD stoves, but not for 
>> the old-hat ICS stoves, including rockets.
>>
>> Nathan Puffer''s work was not quantitatively evaluated. It was a 
>> demonstration that made its point but was not in a way that could be 
>> into large numbers of stoves at that time and still today.
>>
>> 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 4/29/2017 9:46 PM, Ronal W. Larson wrote:
>>> Paul,  cc Nathan and list
>>>
>>> Thanks for bringing up the two subjects of a)  separately 
>>> controlling secondary air, and b) oily (mostly seed?)  fuels.
>>>
>>> I agree that we should be controlling secondary air, but I am pretty 
>>> sure that we should and can do this with the same controller as for 
>>> the primary air.  Most TLUDs already can and should control primary 
>>> air, but make no effort to control the secondary air.   My reason 
>>> for preferring to use one controller for both is that the ratio of 
>>> primary to secondary should always be the same if we want (or can 
>>> live with) a fixed ratio for excess air.   One controller is cheaper 
>>> and is easier for the cook.   Anyone disagree?
>>>
>>> On the subject of using Jaropha seeds,  I am pretty sure that we 
>>> would need a larger amount of “secondary” air than for non-oily 
>>> fuels, but that there still could be a single air controller (just 
>>> with a larger SA/PA ratio  [ maybe goes from about 6:1 up to 7:1 
>>> ??].  Note that these oils cannot combust as they pass through the 
>>> hot charcoal above the downward moving pyrolysis front (no oxygen in 
>>> that stream).  But I presume the temperature is enough for them to 
>>> arrive above the char as quite a different set of gases.  So,  I’d 
>>> like to hear more about what Nathan found.  Any cite we can look up?
>>>
>>> I agree with the rest of Paul’s comments.  TLUDs are not yet a 
>>> mature technology - but it is growing up;  it is not standing still.
>>>
>>> Ron
>>>
>>>
>>>> On Apr 29, 2017, at 8:14 AM, Paul Anderson <psanders at ilstu.edu 
>>>> <mailto:psanders at ilstu.edu>> wrote:
>>>>
>>>> To all,                   29 April 2017     [This note contains 
>>>> some new content and explanations for the advancement of TLUD stoves.]
>>>>
>>>> 1.  Ron:    I and probably some others have successfully used dung 
>>>> as the input fuel into TLUDs.    I am not recommending dung, but if 
>>>> it is being burned, then a TLUD is preferred for cleaner burning.
>>>>
>>>> 2.  AD:   I agree with Ron that the TLUD stoves are better with 
>>>> both light and hard (heavy) wood than direct burning of them in any 
>>>> direct-burning (ICS) stove.
>>>>
>>>> 3.  Main point, to Neil and all:   TLUDs are not burning wood 
>>>> directly.   TLUDs turn wood into gases.   THEN the gases are 
>>>> burned.   So poplar, maple, maize cobs, dung, etc. are ALL becoming 
>>>> gases first.   THEN the burning of those gases might be somewhat 
>>>> different (but not as much as the direct burning of those diverse 
>>>> fuels).
>>>>
>>>> TLUD stoves are just arriving into their "young-adult stage."   In 
>>>> contrast:  not infancy, not childhood, maybe still "youth", but 
>>>> certainly not full maturity, and a long way from  the "old age" of 
>>>> the ICS "Inproved or Inadequate" direct-burning cookstoves.  This 
>>>> is because we are still learning about better and better ways of 
>>>> mixing the combustible gases with  the incoming secondary air (SA)  
>>>> (This is where the BURNING takes place to make the heat that goes 
>>>> to the pot.  TLUDs are DIRECTLY burning GASES, not solid fuels. 
>>>> )    (Please see my "Classification of Stove Technology and Fuels" 
>>>> documents (1-page and 4-page versions) at 
>>>> http://www.drtlud.com/2017/04/11/classification-stove-technologies-fuels/ 
>>>> )
>>>>
>>>> The _solid _wood and dung etc are an intermediate stage of the 
>>>> fuel.   Sort of a "storage" stage.  Then pyrolysis "transforms 
>>>> solids into gases plus charcoal".  The created gases are then 
>>>> burned SEPARATELY (by centimeters and seconds, but certainly 
>>>> separately) from where the gases were created.  We do not have 
>>>> clear terminology for this, in layman's terms. The closest might be 
>>>> "gas burning stoves that make their own gases."
>>>>
>>>> So, what development is happening in the early "young-adult" 
>>>> stage?  Control of primary air, learning about solid "intermediate" 
>>>> fuels, and improving combustion of the gases, as well as "new 
>>>> clothes" with sizes and mateials.
>>>>
>>>> Consider this:  We have known of FA (forced air or fan assisted) 
>>>> TLUD stoves from the 1990s. And there has been much progress.  But 
>>>> NO TLUD on the market has SEPARATE controls for "variable flows" of 
>>>> primary air (PA) and secondary air (SA).   THAT control is what 
>>>> will make the difference regarding Neil's initial question that 
>>>> pointed to differences in the initial fuels (and therefore 
>>>> differences in the resultant gases and quantities of gases that are 
>>>> being burned.)
>>>>
>>>> Note that TLUDs can be made with different flows of PA ans SA by 
>>>> changing the sizes and number of holes.  That is a form of "tuning" 
>>>> the TLUD for a specific fuel.   This works great for one initial 
>>>> fuel, but only good but acceptable with other fringe fuels.  I am 
>>>> NOT referring to that work as being "variable flows".   I am 
>>>> referring to when the user can change the flows, even during one 
>>>> batch of fuel.
>>>>
>>>> There has been some researach (mostly unreported and set aside) on 
>>>> variable control of primary and secondary air, using fans.  I have 
>>>> experimented several times.  The "million-dollar-grants" have had 
>>>> laboratory equipment with controlled and measured separate air 
>>>> flows.  Nathan Puffer did it when we were looking at Jatropha SEEDS 
>>>> as a fuel.  Seeds give off additional gases from the vaporization 
>>>> (not pyrolysis) of combustible vegetable oils (carbohydrates), 
>>>> which are much more plentiful in seeds than in stems and branches 
>>>> and leaves, thereby overwhelming the insufficient supply of SA in a 
>>>> "regular" TLUD-FA.
>>>>
>>>> There is a good reason to not have separate control of PA and SA.   
>>>> That reason is the user, the cook.  To need to "dial-in" the right 
>>>> flow of SA (assuming PA flow stays the same) is, for the most part 
>>>> and for most non-scientist cooks, an extra task that could easily 
>>>> be done incorrectly.  And there are the financial reasons of 
>>>> increased cost and maintenance.
>>>>
>>>> But with "separate air-flow control" (not an established term and 
>>>> NOT justifying an acronym like SAC, as in TLUD-SAC), Neil or anyone 
>>>> could put many very different initial fuels into a TLUD and have 
>>>> greater control of the burning of the gases.
>>>>
>>>> More work is needed before TLUD stoves can reach their full 
>>>> potential, while growing in "young-adulthood".  Today (2017), maybe 
>>>> 40% of what can be known about TLUD stoves is now known (but not 
>>>> necessarily put into practice by stove manufacturers).
>>>>
>>>> (This note is being placed at the EPosts section of my website 
>>>> www.drtlud.com so that it can  be accessed continually instead of 
>>>> only one time on the Stove Listserv.)
>>>>
>>>> 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
>>>>
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>>>
>>
>

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