[Stoves] Understanding "charcoal making" stoves. Was: energy lost in charcoal making and briquetting

[Paul S. Anderson]

Quoting Steve Taylor <Steve at thetaylorfamily.org.uk>:

> Kevin Chisholm wrote:
>> I would suggest that the above definition is a good definition of a
>> gasifier.
>>
>
> Aha ! Agreement. Lets mark that one up then. Gasifier. Defined.

Nice try, Steve and Kevin.  But agreement by 2 people does not constitute an
acceptable definition to be used by hundreds.   :-))

There is some agreement that GENERALLY a stove is a device that gives usable
heat, but there are also furnaces and boilers and other things.  I like the
definition that Tom copied from the Stoves Internet site.

Now, about gasifiers.  Kevin wrote about "combustion" being the ending 
action of
a stove before the heat goes to the pot.  Seems reasonable.

And he also mentioned that there can be the creation of gases BEFORE the
combustion, and that if there is not an associated combustion of the gases, it
would be a gasifier.  But if those gases were combusted, it would be a 
stove. Therefore, it follows that the "gasifier" (that specifically 
makes gases
without associated secondary air for combustion) can be "INSIDE" or part of a
stove.  That means there can be "gasifier stoves" and "non-gasifier stoves."

Note that I wrote "gasifier" (that physical device that makes gases 
separately)
and did not write "gasification" (the chemical processes necessary for all
stoves to make heat from dry biomass).

Therefore, if the gas-making component can be identified and operated 
separately
from the combustion, then that could be called a "gasifier stove", with the
designation of "stove" indicating that the gases are combusted in a context
reasonably but directly associated with the gasifier.

But if the gasification processes cannot be confined to some physical 
component
of the whole device, then the whole device can be a "stove" but is not a
"gasifier stove."

And that is the case of Crispin's Vesto.  It does (at least at certain times)
create gases that can be visually observed, but it does not allow the separate
control or containment of the gasification processes.  I believe that a 
correct
clasification would be a "quasi-gasifier stove", related in processes 
but not in
design to the quasi-gasifiers seen in China.  I believe that "quasi-gasifier"
devices have great merit and can indeed be better (lower emissions) than the
stoves with the "standard combustion" as seen in a match or a flaming stick of
wood.  (I did not attempt to compare the emissions of the quasi-gasifiers and
the various gasifiers.  Please change the Subject/thread if you want to enter
into that topic.)

Kevin gave us a list of seven criteria that could be used to classify 
stoves.  I
counter by saying that EACH of the seven can serve as one way to classify
stoves.  But to combine them into some giant matrix does not constitute a
meaningful classification, but does yield a complex "description" without
classification.

Consider that JUST for the criteria of "heat creation" ("burning" or
"combustion"??) we need some identifying "labels" that do not overlap 
too much.
Note that I wrote "heat creation" and not "combustion" because converting dry
biomass to heat involves the creation of the gases and the oxidation (commonly
called combustion) of those gases.  It is not appropriate to use a word to
define itself, especially if multiple components are involved, with ONE of
those components having the same name as the full term that is being defined.

In other words, it does make sense to call something a "gasifier stove" to
distinguish it from other types of stoves.

I will need to be careful to always say "T-LUD gasifier stove" when 
referring to
the Reed and Anderson and Philips devices.  They cook, they have a gasifier
component/stage, and they have top-lit updraft operation.

Concerning what started this whole discussion, namely the Karve and Larson
charcoal makers, I accept to call them "T-LUD stoves" or even "T-LUD
quasi-gasifier stoves" or "T-LUD not-gasifier stoves" or (probably best)
"Karve-Larson charcoal making stoves".

Paul



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