[Stoves] Aside on coconut husks- continued

Wed Apr 11 21:28:41 CDT 2007

Michael,

Thanks for the clarification.  I will from now on keep the brown dry husks in
mind when I discuss burning them.

For use in a TLUD device, let's consider the 1/3rd husk as a "wedge".  
What are
the length, width, and thickness of a wedge in your country?

I hope that other readers will send us the wedge sizes for the 
Philippines, Sri
Lanka, Cambodia, etc.  There are some large differences.

A TLUD that would take full-size husk-wedges would need to be rather large,
certainly too large to serve as a residential cookstove.  So, what are the
options to "easily" make the wedges into smaller pieces?

1.  Cut in half each wedge.  Would probably need a saw, because cutting across
the husk fibers of a dry coconut husk is (I believe) difficult with a 
machete. If an electric saw is available

2.  Can a wedge (or half wedge) be split easily along the fiber?

3.  Any devices available for assisting with making smaller pieces?

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 Michael N Trevor <mtrevor at ntamar.net>:

> Green nuts are a very improbable fuel source. They are available almost
> exclusively only from harvesting
> drink nuts which means climbing the trees. It is true that the green husk
> are relatively easy to cut and split.
> but difficulty getting it and limited supply are major issues. It is also
> very wet and damp requiring
> weeks to dry.
>
> The Brown dry ones one are what most people are dealing with. These are
> mature nuts which have fallen to the ground.
> These are the normal nuts harvested for copra making or even grated coconut
> as eaten. The nuts are husked by being force down on a sharp stick or pipe
> and twisted to split the husk. It take no more than a few seconds per
> coconut and a skilled copra make usually removes the husk
> in three section which are still semi attached to each other. For fuel these
> are generally or rent or split into separate sections and sun dried.
> and by the bag full are no where as light as they might appear. They are
> also remarkably tough as anyone who has receive a gift coconut
> from Florida, the Bahamas, or Hawaii can attest. These people usually spent
> the next several hours trying to split and tear the husk
> off . Many people end up doing little more than ripping the husk off shred
> by shred with pliers to finally reach the coconut inside.
> To see some one actually husk a nut with a husking stick is total
> revelation.
>
> Copra making in itself is brutally hard work requiring gathering hauling
> husking cracking and drying of thousands of coconuts per
> ton. Moving it around means carrying sacks that often weigh well over a 100
> pounds each and there repetitive motions in cracking
> and cutting coconut meat from the shells that would delight a repetitive
> motion injury specialist. Thing is when all the work is done
> cubic yards of husks left over. In most rural areas it is simply burned to
> dispose of it so air pollution, and soil degradation are the end result.
> So we come full circle back to how to better use it as fuel or even char it
> as a potential terra preta medium.
>
> Michael
> Enemanit
>
>
>
>
>
> ----- Original Message -----
> From: "Paul S. Anderson" <psanders at ilstu.edu>
> To: "Discussion of biomass cooking stoves" <stoves at listserv.repp.org>;
> "Michael N Trevor" <mtrevor at ntamar.net>
> Sent: Thursday, April 12, 2007 12:51 PM
> Subject: Re: [Stoves] Aside on coconut husk
>
>
>> Michael and all Stovers,
>>
>> If the dry coconut husks yield a smokey traditional fire, that is of
> little
>> consequence for the TLUD gasifier usage of husks.  TLUDs as gasifiers are
>> constructed to produce smoke and then SEPARATELY burn the smoke.  More
> smoke
>> yields more flame.
>>
>> The gasifier flames are NOT at low temperatures, so Michael's comments
>> about the
>> advantages of the low temperature husk burning will not be available via
> the
>> gasifiers (except that the cook can move the pots, etc away from the
> direct
>> flames).  We will need to experiment to determine how much "turn down
> ratio"
>> can be achieved in a TLUD that has coconut husks as fuel.
>>
>> Michael wrote:
>> > As for moisture content in husk, it is highly variable. It is nearly dry
> in
>> > relatively fresh unhusked nuts.
>>
>> I have seen dry, very brown coconuts.  Are you referring to these nuts?
>>   And are
>> those the nuts that are desired for harvest and processing?  To me, the
> dry
>> brown husks are hard to cut.  Am I correct about this and about the next
>> paragraph?
>>
>> In contrast, when the un-cut nuts have high moisture and greenish
> appearance,
>> the large knife can cut the husk easily, giving nice pieces that will dry
> and
>> be correctly sized fuel for the TLUD gasifiers.
>>
>> A TLUD gasifier specifically for coconut husks will probably have a
>> diameter of
>> 8 or more inches (20 or more cm).  Therefore, the fuel size can be larger
>> chunks than for the smaller diameter TLUDs that are burning wood chips or
>> coconut shell pieces.  The husk pieces could be in sizes between 1 inch
> cubes
>> to 3 inch cubes, or any irregular sizes that have no measurement
>> greater than 4
>> inches.  These should be easy to make with a machete.
>>
>> What is the common practice in the Marshall Islands for cutting off the
> husks,
>> and how many days of drying?
>>
>> 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 Michael N Trevor <mtrevor at ntamar.net>:
>>
>> > Coire are the fibers in the husk. Industrially today in general husks
> are
>> > mechanically beaten
>> > and pounded to release the fibers and pith from each other. The fibers
> are
>> > combed to separate
>> > the pith. The fibers have many uses and the pith can be recycled into a
>> > masonite like press board.
>> > Even Mercedes Benz was making use of coconut husk materials. Here in the
>> > Marshall Islands
>> > retting was carried out to obtain the coire fibers to hand twist the
> ropes
>> > and twine needed to
>> > construct and sail the traditional canoes.
>> >
>> > As for moisture content in husk, it is highly variable. It is nearly dry
> in
>> > relatively fresh unhusked nuts.
>> > Once coconuts are husked and the interior exposed they can reach 100%
>> > saturation.  Therefore after
>> > husking the sun drying of split pieces of husk as fuel is common. The
>> > picking up, hauling,  drying, and storing
>> > requires considerable time and effort on the part of women and girls.
>> > However, discounting labor it costs
>> > little.  While it is low in heat value, its plentiful nature and being
>> > essentially "free" make it a preferred fuel.for
>> > many here. In spite of its volumous smoke output,  dry,  it is actually
> is
>> > good fuel for certain uses: its low temperature makes
>> > it good for not burning rice soups and stews. Roasting breadfruit is
> best
>> > done on husk too, wood coals and charcoal
>> > are too hot. This results in a quick burning of the outside while not
>> > allowing enough heat to penitrate and cook through
>> > into the center portions.
>> >
>> > Culturally it is interesting to note how people have adapted and used
> their
>> > resources and the "3 stone fire" to take advantage
>> > of what they have available. As we proceed working on better stoves,
> which
>> > certainly have myriads of good uses and benefits
>> > there maybe local practices that need to be considered as well to
> facilitate
>> > adoption.
>> >
>> > Michael N Trevor
>> > Enemanit.
>> > Marshall Islands
>> >
>> >
>> > _______________________________________________
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>> >
>>
>>
>>
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