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<div class="moz-cite-prefix">Dear Rolf, (and hello to Greg!!)<br>
<br>
I am very interested in your method of whole log gasification.
In particular, I am interested in your statement that the
pyrolysis occurs first (or mostly first is fine), leaving the char
to either be consumed (char gasified) or removed. My interest
is in removing / saving the char for a variety of other purposes,
including possible use as biochar. (I am interested in using
the heat, but that can be treated as a separate topic.) <br>
<br>
Therefore, I am sending this message to the Biochar Listserv.
But because relatively few people subscribe to both lists, I (and
Ron Larson and Tom Miles) will relay your reply to the Biochar
List. Eventually these messages could be taken off of the
Gasification List and just continued with the Biochar list, but
let's see what develops.<br>
<br>
Could you please provide some:<br>
some photos,<br>
construction plans if available, <br>
and some data on what percentage of char is yielded from the dry
weight of the feedstock logs.<br>
<br>
I am content with using cordwood that is smaller than the 45 cm
diameter that you mention, so any comments about the good or bad
of using 10 cm or 25 cm diameter feedstock would be appreciated.<br>
<br>
Although as you say it is "a tad late", I will count your message
and replies among my most treasured presents received this year
for Christmas!!<br>
<br>
Paul<br>
<pre class="moz-signature" cols="72">Doc / Dr TLUD / Prof. Paul S. Anderson, PhD
Email: <a class="moz-txt-link-abbreviated" href="mailto:psanders@ilstu.edu">psanders@ilstu.edu</a>
Skype: paultlud Phone: +1-309-452-7072
Website: <a class="moz-txt-link-abbreviated" href="http://www.drtlud.com">www.drtlud.com</a></pre>
On 12/26/2013 5:16 PM, energiesnaturals wrote:<br>
</div>
<blockquote
cite="mid:of3j5vlbe5pox4bcm62wgun7.1388099785538@email.android.com"
type="cite">
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<div>Merry Christmas Ken and list ( I am aware that I am a tad
late)</div>
<div><br>
</div>
<div>One way to burn whole logs like we do (45cm across x 55 cm
long) in an efficient way is to build a well closed ,dome shaped
burning chamber out of 15 cm fire brick and have individually
regulated, preheated primary and 2,dary air , at least 2 pipes
either side.</div>
<div>You build up afire with kindling as you describe it and after
15 min you can add an entire log of pitchy pine and it will
first gasify very nicely and than burn the charcoal if you want.</div>
<div>The secret is to keep the walls of the combustion chamber
warm and do not use them as heat xchangers!</div>
<div>You build a convenient xchanger above it and use the hot
exhaust gas. Build it large enough to reduce the exhaust temp to
90 deg C or less and you will be way above 50 % eff. Ours has
been working for 20+ years and is still doing fine with 2 mm
black steel pipes.</div>
<div><br>
</div>
<div><br>
</div>
<div>We never cut anything below 55 cm long and never split
anything below 45 cm, believe me or come and see!</div>
<div><br>
</div>
<div>Cheers and a happy new year</div>
<div><br>
</div>
<div>Rolf</div>
<div><br>
</div>
<div><br>
</div>
<div><br>
</div>
<div>
<div style="font-size:100%">Enviado desde Samsung tablet</div>
</div>
<br>
Ken Boak <a class="moz-txt-link-rfc2396E" href="mailto:ken.boak@gmail.com"><ken.boak@gmail.com></a> escribió:<br>
<div dir="ltr">Greg
<div><br>
</div>
<div>Thanks for sharing.</div>
<div><br>
</div>
<div>I want to try a few ideas for myself to see if this is
indeed possible on the small split logs I can produce locally.</div>
<div><br>
</div>
<div>Our heating needs, and indeed modest on account of the mild
climate here, but I would like to find an efficient solution
for all the thousands of acres of neglected coppiced hardwood.
Cast iron victorian stoves may be quaint, but I am sure there
are ways to improve the overall efficiency with radical
redesign.</div>
<div><br>
</div>
<div>The main burner/heat exchanger on our 24kW gas boiler is no
bigger than a gallon paint tin. Perhaps there is design
lesson to be learned here</div>
<div><br>
</div>
<div>Anything to reduce mechanical handling and processing of
wood fuels has to be a step in the right direction</div>
<div><br>
</div>
<div><br>
</div>
<div>Happy New Year </div>
<div><br>
</div>
<div><br>
</div>
<div><br>
</div>
<div>Ken</div>
<div><br>
</div>
</div>
<div class="gmail_extra"><br>
<br>
<div class="gmail_quote">On 26 December 2013 19:22, Greg Manning
<span dir="ltr"><<a moz-do-not-send="true"
href="mailto:a31ford@gmail.com" target="_blank">a31ford@gmail.com</a>></span>
wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div dir="ltr">Greetings Ken, and list members.
<div><br>
</div>
<div>Ken, I'm going to point you to a video of the
"underside" of a whole log (or split) "cordwood as we
call it here" stove that is a downdraft gasifier.</div>
<div><br>
</div>
<div>I can speak at length privately, however only
somewhat on list, as this is a proprietary design. </div>
<div><br>
</div>
<div>Here's the link to the video:</div>
<div><a moz-do-not-send="true"
href="http://youtu.be/DNYCfgEdYpg" target="_blank">http://youtu.be/DNYCfgEdYpg</a><br>
</div>
<div><br>
</div>
<div>Greg Manning</div>
</div>
<div class="gmail_extra"><br>
<br>
<div class="gmail_quote">
<div>
<div class="h5">On Thu, Dec 26, 2013 at 12:59 PM, Ken
Boak <span dir="ltr"><<a moz-do-not-send="true"
href="mailto:ken.boak@gmail.com" target="_blank">ken.boak@gmail.com</a>></span>
wrote:<br>
</div>
</div>
<blockquote class="gmail_quote" style="margin:0 0 0
.8ex;border-left:1px #ccc solid;padding-left:1ex">
<div>
<div class="h5">
<div dir="ltr"><br>
<div>Happy Christmas to the gasification list.</div>
<div><br>
</div>
<div>At this time of year, during the festive
holiday season, I get a bit more time to
manage the running of our woodstove, as it
rapidly warms the room and produces a cheery
effect.</div>
<div><br>
</div>
<div>Our property is fairly conventionally
heated by natural gas, but a few years back, I
took the decision to invest in a woodstove
with back-boiler, to provide an alternative or
back-up to the gas fired system.</div>
<div><br>
</div>
<div>The woodstove has a flat steel tank at the
rear, the "back boilerr", in place of a couple
of the firebricks lining. This circulates
heated water entirely by the thermosyphon
principle to a radiator located in the
bedroom/workroom directly above the stove. So
in effect the stove heats the living
room/kitchen area directly, and the room
upstairs by circulating hot water.</div>
<div><br>
</div>
<div>No electricity is required for circulation,
and if worse-case we had an extended power
outage, this stove would provide heat and
comfort in the two main occupied areas of the
house. Stoking it and attending it is often
more interesting than what is being shown on
TV!</div>
<div><br>
</div>
<div>With a few days off work, I have had time
to monitor the stove and make some assessments
of its overall performance. Its a fairly
traditional stove, a rectangular box,, made
from bolted together cast iron panels and
partly lined with firebrick. It's described as
a multifuel stove - having been supplied with
a cast iron removable grate for burning coal -
which is not used when burning wood. It's
approximately 24" wide, 12" deep and 18" tall.</div>
<div><br>
</div>
<div>In the UK, a common size for firewood logs,
intended for the domestic woodstove is about
10" (254mm) long, and equal to a 1/4 round
taken from a limb that may have been 5 or 6"
in diameter. The reason for this is that
there is a lot of coppiced hardwood, which has
become mis-managed in the last 20 years, so
there are a lot of trees with 6" diameter
shoots. The popularity of the "firewood
processor" machine, means that a lot of this
wood is now coming on the market as domestic
firewood, and sold to suburbanites at vastly
inflated prices (about $0.50 per kilo).<br>
</div>
<div><br>
</div>
<div>I am burning a mixture of kiln dried Silver
Birch, and air dried other species which
includes ash, oak and sweet chestnut. The
silver birch splits well and makes excellent
kindling. One log is split into 8 or 10
kindling sticks and these are built into a
pyramid around 2 or 3 sheets of scrunched up
newspaper. Lighting is quick and easy - as the
birch is kiln dried, and within 5 minutes you
will have a roaring fire and the larger logs
can be added.</div>
<div><br>
</div>
<div>The logs have an average weight of
approximately 1 kg. I have found that a
normal burn rate of these is two per hour. I
burn two at a time, and each hour, add a
further two to the burning char bed from the
previous logs. With firewood having a
calorific value of approximately 4kWh/kg - I
estimate the fuel input is in the order of 8
to 10kW.</div>
<div><br>
</div>
<div>Of course, with a traditional stove, so
much of the heat energy is lost up the
chimney, and goes to create the draft. The
efficiency of the stove, might be in the
region of 50% - somewhat better than the open
wood fire. It occurred to me that by way of a
2 stage gasification process, it would be
possible to increase the overall system
efficiency, resulting in less wood
consumption, or more heat output per log.</div>
<div><br>
</div>
<div>This leads to a question - is it possible
to design a gasifier aimed at handling whole
log gasification - where a log is 10" long and
no more than 6" across? Can you recreate the
temperatures, turbulence and reactants, found
within the combustion zone of the woodstove,
and use this to thermally process a single
firewood log, at the rate of one every 30
minutes or so?</div>
<div><br>
</div>
<div>I've had some ideas on how this can be
done, effectively using a length of 6"
diameter stovepipe/fluepipe to make a compact
gasifier. Logs would be loaded in from the
top, and the length of the pipe chosen to
perhaps hold 4 logs at any time - about 1m
(40") tall. The bottom log would sit in the
combustion zone - so the end of this log is
constantly under the action of the air
nozzles. The logs above are subjected to the
elevated temperatures and begin to pyrolise,
char and split on their descent down the tube.</div>
<div><br>
</div>
<div>Beneath the combustion zone would be a
fairly conventional hearth, and reduction
zone, with the char supported by a grate below
that. For an overall idea of the system -
think of HS Mukundas open top gasifier. </div>
<div><br>
</div>
<div>Use of twin-wall stainless flue pipe would
allow the air to be pre-heated in the outer
annulus - adding to the overall efficiency.
The hot syn-gas could be burned in whatever
appropriate burner geometry deemed necessary
for either radiant space heating or water
heating with a suitable heat exchanger coil.</div>
<div><br>
</div>
<div>I hope to try to build a prototype of this
over the next 10 days (a working gasification
holiday?) and to see whether a log can be
reduced in this manner. If all that is needed
is heat, then the restrictions to produce a
tar free gas need not apply. If one can use
whole logs, without having to resort to
woodchip - then this will be a considerable
saving in mechanical handling and wood
processing.</div>
<div><br>
</div>
<div>At the end of the day - this gasifying
stove needs to be as simple to operate as the
existing woodstove. Reloading with a couple
of logs each hour, and no sophisticated need
for fan- forced draft or electricity to
operate. Draft would come from the chimney as
per now - about 25 to 30 feet, 6" diameter.</div>
<div><br>
</div>
<div>If anyone has experience of something
similar - please let me know.</div>
<div><br>
</div>
<div><br>
</div>
<div>Happy Holidays</div>
<span><font color="#888888">
<div><br>
</div>
<div><br>
</div>
<div><br>
</div>
<div>Ken</div>
<div><br>
</div>
<div><br>
</div>
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