[Cob] Joe Kennedy comments on biochar in earth ovens

[Shawn King]

Hi Joe, I like the plugs idea, easy to make from common raw material.
I think a coil or snake of chicken wire and charcoal lowered/stuffed
into the chimney might also work, and provide even more surface area.
My chimney requires some reinforcement before I can try that idea.

I think the vermiculite cob is a step up for the rocket door design.
What I have works well, but the weight of the door arch is a nuisance.

Great stuff all around!

Shawn :)

On Mon, Apr 25, 2011 at 5:39 PM, Joseph Kennedy
<livingearth62 at hotmail.com> wrote:
> Hi Shawn,
>
> I am thinking to create a biochar drawer that would fit in the lower slot of
> your rocket door.  In my design, I think the gases would ignite, even though
> the main fire will be in the chamber below.
>
> I like the carbon scrubber.  I am planning to make a chimney plug of a
> ceramic flower pot filled with vermiculite cob.  I could use the same size
> flower pot to form carbon plugs with chicken wire and biochar (i.e
> charcoal).  I am also thinking of vermiculite cob to make the oven door per
> your design.
>
> All the best,
>
> Joe
>
>> Date: Mon, 25 Apr 2011 16:48:39 -0700
>> From: sbkingster at gmail.com
>> To: livingearth62 at hotmail.com
>> CC: coblist at deatech.com; albert at thefarm.org
>> Subject: Re: [Cob] Joe Kennedy comments on biochar in earth ovens
>>
>> Joe and Ray,
>>
>> Hmmm, Joe, I like the drawer idea. I'll keep an eye out for an old
>> popper, likely to work well and have a great vibe! I'm thinking heat
>> loss would be a minimal issue as the heat is stored in the mass walls,
>> not in the air, so opening/closing won't cause much loss in most
>> designs, unless you are also loosing a lot of mass wall area in the
>> design. My oven "breaks the rules" as the door is wider than would be
>> considered optimal to allow use of an earthen crock for slow cooking
>> stews after the bread/pizza etc. is done. It still works, but I think
>> I do loose a little efficiency by having a >50% door width rather than
>> the approx 1/3 recommended traditionally. Maybe the drawer could be
>> built into a metal "rocket door" type retrofit, with the drawer
>> sliding in above the rocket door tube.
>>
>> I'm not sure how air tight the biochar unit needs to be. The canister
>> is pretty well sealed except for the burner holes. This may be key in
>> getting combustion to stop on its own when the pyrolysis gasses are
>> exhausted, a good feature IMHO.
>>
>> I need to get good data on the canister method on my next firing.
>> Weight of the wood mass before and after char, some estimate of volume
>> as well, and maybe the length of time a can-full will burn gasses. I
>> would also like to try bamboo from local sources as a biochar fill,
>> see what happens. Our sycamores drop lots of small branch material
>> every year, twigs may just be the easiest and most available thing,
>> but I bet bamboo will make prettier charcoal.
>>
>> Another experiment I'd like to try is a crude charcoal filter built
>> into the chimney, likely near the end, to filter out some of the smoke
>> that seems inevitable when you first fire up. Make your own filter
>> charcoal! Could be something easy, a slot in the chimney for a couple
>> of layers of charcoal in wire cages - maybe those old wire smore
>> cookers, or something of the like. Change the charcoal out
>> frequently, and keep it loose in the cage for maximum air flow,
>> causing the exhaust to roll over and around charcoal pieces. Even if
>> you only got half of the soot and other smoke nasties out of the
>> exhaust, it would be well worth it.
>>
>> Plenty left to do!
>>
>> On Mon, Apr 25, 2011 at 3:49 PM, Joseph Kennedy
>> <livingearth62 at hotmail.com> wrote:
>> > Dear Shawn and Ray,
>> >
>> > I am thinking of a biochar "cooker" that could be inserted like a drawer
>> > into the firing chamber and easily slid out with not too much loss of
>> > heat.
>> > Maybe several interchangable drawers, like old 8-tracks that could
>> > be slotted in and removed when the biochar is ready, with the biochar
>> > removed as generated during the firing of the oven.  Or maybe like those
>> > old
>> > fashioned popcorn poppers used in fireplaces, now that would be a cool
>> > use
>> > of old tech!  Gotta find me one of those to try.  Biocharpopper.
>> >
>> > Mad science for all!
>> >
>> > Best,
>> >
>> > Joe
>> >
>> >> Date: Mon, 25 Apr 2011 12:47:55 -0700
>> >> From: cobanation at yahoo.com
>> >> To: sbkingster at gmail.com; coblist at deatech.com;
>> >> livingearth62 at hotmail.com
>> >> Subject: Re: [Cob] Joe Kennedy comments on biochar in earth ovens
>> >>
>> >> Dear Joe,
>> >> We just launched the Dragon Pizza Oven and it was a smash hit. We ran
>> >> it
>> >> for five straight houts and collected at the end only a half cup of
>> >> biochar.
>> >>
>> >> Regards,
>> >> Ray
>> >>
>> >>
>> >> The Great Challenges we now face as a species present the very
>> >> opportunities that are giving birth to Ecological, Psychological, and
>> >> Spiritual Sustainability.
>> >>
>> >>
>> >> --- On Mon, 4/25/11, Joseph Kennedy <livingearth62 at hotmail.com> wrote:
>> >>
>> >> > From: Joseph Kennedy <livingearth62 at hotmail.com>
>> >> > Subject: [Cob] Joe Kennedy comments on biochar in earth ovens
>> >> > To: sbkingster at gmail.com, coblist at deatech.com
>> >> > Date: Monday, April 25, 2011, 12:03 PM
>> >> >
>> >> > Dear Shawn,
>> >> >
>> >> > I have been inspired by your low-tech stuff, and am going
>> >> > to integrate the door design into my new oven under
>> >> > construction with high school students.
>> >> >
>> >> > However, it seems a waste to make biochar unless you are
>> >> > using that heat to heat up the oven for other purposes.
>> >> >
>> >> > To me the ideal would be to make a biochar chamber below
>> >> > the oven (like in Ray Cirino's example) to create efficient
>> >> > heat and biochar at the same time.  Any ideas on this
>> >> > option?  I can play around with this idea, since my
>> >> > oven is still under construction.
>> >> >
>> >> > I love the mad science going on!
>> >> >
>> >> > All the best,
>> >> >
>> >> > Joe Kennedy
>> >> >
>> >> > PS.  I just published an article of my earth oven
>> >> > odessey at Kiko Denzer's site.  It has the plans of my
>> >> > latest oven.
>> >> >
>> >> >
>> >> > http://www.handprintpress.com/ovens/an-earthen-oven-odyssey-by-joe-kennedy/
>> >> >
>> >> >
>> >> >
>> >> >
>> >> >
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