 |
 |
|
 |
 |
 |
 |
 |
 |
 |
 |
| |
REPP-CREST
1612 K Street, NW
Suite 202
Washington, DC 20006
contact us
|
|
 |
|
|
|
|
| Gasification Archive for September 2002 |
|
| 114 messages, last added Tue Nov 26 17:18:28 2002 |
[Date Index][Thread Index]
GAS-L: SIMPLE CHARCOAL MAKER... SMOKY?
Andrew and All:
Sounds simple, but smoky. Is there a way to burn off the smoke?
In general charcoal is a clean fuel for the user, but the smoke has been
donated to the atmosphere during making it. "Polution solution by dilution"
is the old way, but we'd like to find a better.
TOM REED
----- Original Message -----
From: "AJH" <andrew.heggie@dtn.ntl.com>
To: <gasification@crest.org>
Cc: "Stoves" <stoves@crest.org>
Sent: Monday, September 16, 2002 6:15 AM
Subject: Re: GAS-L: Re: SIMPLE CHARCOAL MAKER...
Xposted to stoves
On Mon, 16 Sep 2002 09:13:31 +1200, "renertech" <renertech@xtra.co.nz>
wrote:
>Folks, there s an even simpler method of making charcoal than all those
>pretty pictures. It is called the "Tongan Drum" method. All you need is one
>old drum (Barrel) with a 9" wide slot cut out of the side, and the full
>length of the drum. You start with the drum lying on its side and the
>slot at the 9 O'clock position. Once you have a good fire going you
>wait till the smoke diminishes before adding more wood and waiting for
that
>too to burn off the volatiles.
>When the drum is full of hot charcoal to the edge of the slot you simply
>roll the drum
>over until the slot is at 11am. and keep adding wood. When the slot is
>vertical and the drum is full of redhot embers, you just roll the drum
>quickly right over, to p ut the slot at the bottom, and shovel dirt
around
>the edges to block off the air. And next day you have a full drum of
>charcoal. Back on the beautiful island of Tonga , one man could operate
>about 16 of these drums at once to run a complete commercial charcoal
>operation with supplies of mangrove wood, supply the BBQ market with a
>very high quality charcoal. Ken Calvert.
Good stuff Ken, this is the boy scout way of making charcoal. It does
scale up really well and then lends itself to mechanical loading, on
this scale I refer to it as the modified pit method (I have used both
ring kilns and a 3000 litre tank) and the output per man can be
amazing (I think I estimated 2 tonne in 3 hrs on an attempt 3 years
ago). On the large scale cooling becomes a big issue.
It works well with dryish material of small cross section. I believe
this is because the only feedback path to maintain pyrolysis
temperatures is radiative from the flame and thence conductive through
the wood. It is similar to adding fresh would to an idd stove in char
making mode. The pyrolysis has to complete at the same rate as the
flare.
There is nothing new in the technique it is described in Evelyn's
sylva c1760. He suggests digging a pit and lighting a fire in it, then
throwing in bavins (loose bundles of coppice material) until each
succeeding layer is carbonised, when full the pit is covered and
allowed to cool for many days. A similar technique was exported to
Africa, here a btd6 sized dozer would carve out the pit and then cover
it at end of burn.
If the flare is clean then this may not have a lot of pollution,
however the fact remains that 70% of the available energy in the wood
is lost to entropy heaven.
AJH
Gasification List Moderator:
Tom Reed, Biomass Energy Foundation, tombreed@attbi.com Biomass =
Energy Foundation, www.woodgas.com
List-Post: <mailto:gasification@crest.org>
List-Help: <mailto:gasification-help@crest.org>
List-Unsubscribe: <mailto:gasification-unsubscribe@crest.org>
List-Subscribe: <mailto:gasification-subscribe@crest.org>
-
Gasification List Archives
http://www.crest.org/discussion/gasification/200202/
Bioenergy 2002 http://www.bioenergy2002.org/
200 kWe CHP Discussion
http://crest.org/discussiongroups/resources/gasification/200kWCHP.html
Gasification Reference
http://www.crest.org/articles/static/1/1011975339_7.html
>
Gasification List Moderator:
Tom Reed, Biomass Energy Foundation, tombreed@attbi.com Biomass =
Energy Foundation, www.woodgas.com
List-Post: <mailto:gasification@crest.org>
List-Help: <mailto:gasification-help@crest.org>
List-Unsubscribe: <mailto:gasification-unsubscribe@crest.org>
List-Subscribe: <mailto:gasification-subscribe@crest.org>
-
Gasification List Archives http://www.crest.org/discussion/gasification/200202/
Bioenergy 2002 http://www.bioenergy2002.org/
200 kWe CHP Discussion
http://crest.org/discussiongroups/resources/gasification/200kWCHP.html
Gasification Reference http://www.crest.org/articles/static/1/1011975339_7.html
>
|
|
|
