[Stoves] Comments about T-LUDs

[frank at compostlab.com]

Paul,
As I see it there are two types of carbons left in the ash. One carbon that is
left from the unburned wood and the other carbonates. Carbonates are common in
manures and soil contaminated organics but I have not found much in clean
wood.  I have called the carbonates 'fixed carbon' but from reading the test
results  giving of different fuels, I now think there may be another type of
definition of 'Fixed carbon'. We have the D series of ASTM but not the E
series that we need. When I test general ash materials they usually have a lot
of carbonates and some want to use it as a soil additive. If the carbon is
determined by a carbon analyzer like a Leco the carbonates will be included
along with unburned wood in the total carbon value. 

Ash, even in wood, is much more than just unburned organic material. There can
be a lot of silica in the form of phytoliths. I have done a lot of work
extracting these interesting things. It is the silica that forms the shape of
the veins of plants and roots. Like hardening of arteries in people. We have
used them to try to determine what types of plants were growing when the
natives were living in an area several thousand years ago. Rice hulls has a
lot of silica in the tissue. 

In the process, such as I suggest, we now have steam power to work with and I
would like to think of some way we could use it to generate the air pressure
to keep the fire going. I don't think much air is needed to keep the fire
going and it (perhaps) a small percentage from the steam needed to cook the
food. It could press against a balloon, bladder or bag pipe thing as you mention.

Problem, as I see it, with small units is that the fuel must be very
consistent or the flame will go out. Cardboard is such a fuel but I am not
sure it is available world wide. 

I live in a small place and do not have things like pipe cutters, threaders,
welding equipment etc, nor do I really know how to use them. So when i really
start to make a stove it will be a majer thing for me (cost and time and
learning) so I want to solve as many of the problems as I can before I start. 


Thanks


Frank





 
> You raise two excellent questions:
> 
> 1.  Does every type of dry biomass always yield) char/charcoal?  
> Frank has mentioned the testing or measuring of (what is it called?  
> XXX carbon, not the organice carbon).  Does it exist in every type 
> of dry biomass?
> 
> Of course, the processes (plural) of combustion might be able to 
> eliminate the char/charcoal while the pyrolysis and combustion are occurring.
> 
> This is outside of my field, but of considerable interest.  For 
> example, is some
> specific biomass exceptionally high in it yield of char?  Or, as 
> Jeff asks, could his pond scum be exceptionally low in its yield of 
> char?  We know from Alexis Belonio and observation of T-LUD 
> gasification of rice husks that the small, thin husks yield only 
> even smaller and thinner flecks of char.  And algae strands are 
> certainly smaller and thinner than husks.
> 
> I think this question relates to T-LUDs and their fuels, and maybe 
> also to other combustion devices and processes.
> 
> 2.  The tiny and useful Gasifier:  Yes, 1 inch (2 to 3 cm) diameter 
> is a good size to discuss.  I have made them as small as 2 inch (5 
> cm) in diameter, but found no useful purpose at that time.  But what 
> about as a small light or torch?  I suspect that only T-LUD 
> technology might have a chance at accomplishing this.  Other types 
> of gasification seem to be too complex and rely on the fuel moving 
> downward, which would be difficult with so much surface area and 
> resistance relating to the tiny diameter.
> 
> A.  In the T-LUD style, the biggest problem would be to keep air 
> __continually__
> moving upward through fuel.  Maybe a balloon or a bag-pipe bladder 
> could keep the air flowing.  But human blowing is intermittent, and 
> everytime the flow stopped, the gases coming out the end would 
> likely be insufficient to sustain the combustion flame.  And if the 
> flame is gone, blowing again would not reignite the flame.  But 
> perhaps a candle flame alongside the end of the tiny T-LUD might be 
> keep the combustion continuing.
> 
> B.  Insulating the fuel container (which is the gas making part of 
> the device) is important because the lateral loss of heat from the 
> gases would be rapid in a cylinder of such small diameter.
> 
> C.  Length of the T-LUD is a major factor in how long the batch will 
> yield gases.  Therefore, the application/usage should be something 
> that does not require much time.
> 
> D.  Fuel:  There would be many candidates from which to choose.  And 
> the cost of
> the raw material and the labor to have it "just right" for the tiny 
> T-LUD would
> NOT be of much importance because the quantities of fuel would be so 
> small and the "value" of the application would be so high.  Perhaps 
> some "oil-rich" seed or enriched special biomass might work very well.
> 
> Jeff, you have started me (and you and others, I hope) thinking 
> along an additional line of T-LUD development.
> 
> Paul
> -- 
> Paul S. Anderson, Ph.D., Geography professor - Emeritus
> Telephone:  USA-309-452-7072 (residence and office)
> Internet site:  www.ilstu.edu/~psanders
> For my gasifier stoves info, go to:
> http://bioenergylists.org/contributors#Paul_Anderson
> 
> Quoting Jeff Davis <jeff0124 at velocity.net>:
> 
> > Dear Paul,
> >
> > In regards to charcoal/char produced in the T-LUD:
> >
> > In addition to increased air velocity and fuel moisture the fuel it self is a
> > factor (I believe). For example: my pondscum fireballs left no char only ash
> > (I believe). Maybe pondscum and other fuels are carbon anemic? Another
> > aquatic fuel I tested some, (I call it pea-soup) smells like burning hair, so
> > is that protein?
> >
> > Also see note below:
> >
> > Paul wrote,
> >> Paul says:  While the principle of making the gases (smoke) can be
> >> illustrated in the cigarette example, I like to think of gasifiers as being
> >> useful devices that operate with controls.
> >
> >
> > I bet a small gasifier could be made. Maybe one inch in diameter. Small
> > particles for the fuel. Could be used as a candle or small torch.
> >
> >
> > Jeff
> >
> >
> >
> > --
> > Jeff Davis
> > Somewhere 20 miles south of Lake Erie, USA
> > http://www.velocity.net/~jeff0124
> >
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> >
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