[Stoves] Shields E450c as a way to test char-making stoves (attn: GACC testers)

Ronal W. Larson rongretlarson at comcast.net
Wed Oct 23 10:47:23 MDT 2013


Crispin and list

#1.  You have added only extraneous material re naming, China, kilns.  You did not at all address the issue of treating char-making stoves fairly.

#a.  Same response.  You did not address the topic of differentiating between char-making stoves.  Apparently you are happy that your money making stove in Indonesia will receive a report that says nothing about the char produced?

#b1   Same response.  You have a typo "for a that stove"   that precludes a definitive answer since I don't know whether to strike "a" or "the".  I continue to believe that the present approach being used by Jim reports everything you ask for - and always has.  The only new material I know about I am delighted with - the amount of char and the energy in the char is specifically now provided.  It was always there, but hidden.  Char-making stove people couldn't be happier with this small change in reported results.

#b2 -i   You write about the formula A/(B-C):  "...  it has been misleading people ever since it was introduced"
       I agree.  - but for opposite reasons than you.  It undervalues the production of char.   I am willing to let it ride, since my preference is also being shown.

   - ii    You write:   " Char? Fine, if it too can be burned as fuel. If it is not usable, it is not fuel. Same as ash as far as that stove is concerned."   I  am sorry that you don't see how unfair this statement is to char-making stoves -- where people (including you) can make money on the char - whether used as fuel or put in the ground.   You are taking income away from the poorest with your stance.
   
  - iii   Your last sentences:  The WBT was changed and that was the major point of Jim’s recent webinar to which you posed a number of questions and which he answered repeatedly. 
   [RWL:  And I was happy with all the answers.]

I am again answering that same question. 
      [RWL:  With answers different from Jim's]

The fuel consumption considers whether or not the remaining fuel is fuel for that same stove. If it is not, it shall be considered consumed.
      [RWL:   You are (I think) the only one saying this should be the rule.  Certainly no-one who thinks making char in a stove is better economically and environmentally - regardless of where it ends up.  Of course for climate reasons I want it to go in the ground,  but I started on this topic in the early 1990s just to save trees.  Char-making stoves can do both, but since char-makig stoves are more efficient and cleaner, char-using stoves are on their way out.
>  
> End of short story. Take it up with Jim if you do not agree with this reality.
     [RWL:  I see no need to.  I think Jim is handling "reality" correctly and has already said so on this list several times.]







On Oct 22, 2013, at 5:56 PM, "Crispin Pemberton-Pigott" <crispinpigott at gmail.com> wrote:

> Dear Ron
>  
> >Crispin and stoves list  (again ignored - why?)
>  
> 1.      The "game"  I am playing is to ensure that charcoal-making stoves are treated fairly.  Saying that existing char at the end of a run has been "consumed" is not fair.
>  
> How do you suggest we term the fuel that enters a stove once, each time the stove is operated through a burning cycle? Should that be the fuel consumed? The fuel needed per cycle? The fuel use? The fuel demand? Give it a name and let’s see how it flies.
>  
> We are speaking of course of raw biomass in this case. Whatever biomass goes into a stove, per cycle, drawn from the available supply, and which needs to be drawn again the next time, needs a name.
>  
> In the strict sense of the word ‘consumed’ it has been consumed as far as that stove is concerned. In another sense, from an outside perspective which can see additional uses for that remainder, whether it be ashes or char, it has ‘produced something’. No problem. One can view it that way, but it will not change the raw fuel demand for a new cycle unless some of it is fuel to that same stove. There is no other practical way to communicate to people the amount of fuel a stove requires to be harvested and provided each day.
>  
> In China they have a test that runs for a month. A stove is installed and cooked upon each day for a month. The amount of fuel it consumes during that month is calculated. Then they know what the fuel consumption really is. If there is a huge pile of char left afterwards, they do not consider that an ‘efficiency’. I can’t say I am surprised.
>  
> If you are in the char making business, you still have to consider how many cubic metres of trees are needed each day. That is the raw fuel consumption of the char making kiln. The char produced is not a raw fuel efficiency, it is the output efficiency of the char making process. No problem.
>  
> We both owe a duty of care to the people buying and promoting stoves to correctly report the amount of biomass that is needed to fuel the stove per cycle or per day or per month.
>  
> 2.  Under a) - I repeat my original claim - you have no test in mind that will differentiate between char-making stoves.   If char is there, it has not been "consumed".
>  
> Well you can read the above again if you like. If there is char remaining that is not fuel for the stove from which it came, it comes from fuel which the stove consumed. Word it as you like. I thought you would be asking for a report on the char production efficiency with a rating on the energy content per kg and the % volatiles. That would make sense if you wanted to sell it for income. I am hoping to do exactly that in an area of Indonesia where there are many candle nut shells. It makes really good charcoal fuel when burned in a TLUD which people can sell for income.
>  
> When assessing the fuel consumption of the TLUD that makes that char, we will get the mass of fuel consumed per cycle, the energy content and rate it accordingly. Another stove that burns the same fuel and cooks the same amount and produces no char will consume a lot less raw material. All we are doing is reporting how much the stove consume per cycle.
>  
> 3.  Under b) -  The key sentences are your final two:   The direct cause is that the more char produced, the less fuel was claimed to have been consumed, which is clearly untrue. That is why the WBT was changed."       If char exists, the claim of less fuel is "clearly true",  not "clearly untrue".  
>  
> My claim is related to the amount of raw biomass needed to be put into the stove each time it is used. Your claim is to view the char remaining as fuel. This may or may not be true for a particular stove. If that char is fuel for a that stove, then the char can be credited as unburned fuel. The point is to tell the prospective buyer what the raw fuel consumption is.
>  
> Further,  the use of the formula A/(B-C) goes back at least to VITA days and is in there today.   On this main point under dispute, the WBT was NOT changed (thank goodness).  Or if I am wrong, please give a cite.
>  
> Yes it does go back that far and it has been misleading people ever since it was introduced.  It was written on the basis that the desired measurement was not the raw fuel consumed each cycle, but the efficiency with which the heat was developed in the fire and transferred to the pot. That is why it was called (in those tests) the ‘heat transfer efficiency’.  It isn’t really the heat transfer efficiency, but it was given that name. The heat transfer efficiency is a useful number for stove designers. When making changes like pot to stove clearance the number will change. But it is not and never was the fuel consumption figure, even for the fry fuel consumption, because the consumption depends on what happens to the fuel remaining. If it is long sticks that can be burned tomorrow, fine, it is unburned fuel. Char? Fine, if it too can be burned as fuel. If it is not usable, it is not fuel. Same as ash as far as that stove is concerned.
>  
> The WBT was changed and that was the major point of Jim’s recent webinar to which you posed a number of questions and which he answered repeatedly. I am again answering that same question. The fuel consumption considers whether or not the remaining fuel is fuel for that same stove. If it is not, it shall be considered consumed.
>  
> End of short story. Take it up with Jim if you do not agree with this reality.
>  
> Regards
> Crispin

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.bioenergylists.org/pipermail/stoves_lists.bioenergylists.org/attachments/20131023/59e1b2f7/attachment.html>


More information about the Stoves mailing list