[Stoves] Misuderstanding of TLUD stoves Re: Refuelable TLUD Coal Stove developed in Mongolia that is not a batch process.

[Ron Larson]

Paul and ccs:

   I had not realized that your Chip Furnace operated in the manner you describe below.  Am I correct then in assuming that the word pyrolyzer (which you didn't use) would be inapproproriate - and that char production is minimal?

   But also that much of your other writing is on char-making stoves of a batch type and that you would then not use the term "gasifier"?

   I have not heard whether Nat Mulcahy demonstrated at the Ethos meeting that he could add extra fuel at the end of a run - and that TLUD was therefore Inappropriate for his design.

   I believe (perhaps like Crispin) that a BLDD could produce char - and could add extra fuel at the top - and hope that someone will report on that pair of desirable characteristics in a collating.

Ron

   

Sent from my iPad

On Mar 3, 2011, at 12:30 PM, "Paul S. Anderson" <psanders at ilstu.edu> wrote:

> Quoting Crispin Pemberton-Pigott <crispinpigott at gmail.com>:
>    snipped
>> 
>> A TLUD is just a down draft built upside down. They can be refuelled continuously but if the desire is to get char out, that could be a problem.
>> 
> This is a very common misunderstanding that was even promoted by Tom Reed who initialy call it "inverted down draft" gasification.
> 
> In a true downdraft gasifier, there is a hot zone that stays at the bottom all the time, and the fuel moves downward to it, becomes char and is later subjected to char gasification.  The air flow is also downward.
> 
> In a TLUD, the hot zone starts at the top, but then the hot pyrolysis front migrates downward until reaching the bottom of the fuel pile.  That is FUNDAMENTALLY DIFFERENT from the downdraft gasifiers.
> 
> Furthermore, after the pyrolysis front reaches the bottom, the air flow still continues to be updraft.  Placing a significant amount of fuel onto the top of the fuel bed can cause variations in the gases created (initially much water vapor while the fuel is drying, then the pyrolytic gases start later).
> 
> Note:  In the case of the Chip Energy Biomass Furnace (www.chipenergy.com) which is a true updraft gasifier with continuous operation (and the hot zone is at the bottom where the air is entering), the new fuel enters in small amounts, avoiding the problem mentioned in the above paragraph about water vapor.
> 
> I hope this helps explain what is happening in the TLUDs
> 
> Paul
> 
> 
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