[Stoves] The Bean Can Stove

Tue Sep 5 13:24:40 CDT 2006

Paul,
Thank you for your intelligent questions and comments, see my answers below.

----- Original Message ----- 
From: "Paul S. Anderson" <psanders at ilstu.edu>
To: "lannych" <lannych at bellsouth.net>
Cc: <Stoves at listserv.repp.org>
Sent: Saturday, September 02, 2006 10:19 AM
Subject: Re: [Stoves] The Bean Can Stove

Lanny and all,

Nice job!!!

A couple of questions and comments:

1.  One 5-gal bucket is the outer lower unit, but what is the origin of the
inner lower cylinder?  (There is ash insulation between them.)  Are you
cutting
one of the other 5-gal buckets in order to use the sidewalls?  And does the
inner cylinder have its own bottom, or is it sitting on top of the bottom of
the outer bucket?

LH- The "inner shell" is cut from a 5 gal pail using two ribbon cuts, with 
aviation snips and has no bottom.

2.  Being a charcoal burner, most smoke is avoided.  But you still need some
upward draft through the charcoal.  The air enters through the bottom hole, 
up
through the charcoal, the heat hits the pot, but then how do the hot gases 
go
past the pot to the exhaust hole?  I cannot tell from the description
or photos
if there is a gap between the pot and the lid that supports the pot (if
so, how
is the pot held in place, with tabs?) or if there are holes in the support 
lid
allowing the gases to pass upward.  Please give the dimensions and place of
those passages.

LH- The tabs hold the pot, and the hole layout is 1" larger than the pot. 
Just cut around the tabs and bend the up.

3.  I like you "air control" by arising the whole stove on 3 sticks (not
mentioned in the materials list ;-)   ) and then removing them to cut off 
the
air entry.  But this causes movement of the entire stove.  An alternative 
way
is to have the whole unit placed permanently on the support sticks or scrap
metal pieces from the stove construction, and then have a modest amount
of sand
or even dirt that can be pushed against the bottom to fill in the gaps when 
it
is time to close off the air supply.  This can even allow for some desired 
air
entry if a small gap is left opened or re-opened, even to allow for
some forced
air (a simple blow-pipe, etc.) if needed to get the charcoal burning again, 
or
to insert any additional fire if needed for reheating (possibly use a 
shallow
dish with kindling, etc., but this depends on the height of the gap and the
fore-planning of the stove design).  If the sand-seal or dirt-seal needs to 
be
very air-tight, adding a little water will make it well sealed.  (After 
usage,
push the sand / dirt to the side for use with subsequent cooking.)

LH- Good ideas.

4.  In the final step with just retaining the heat, could you place an 
object
(even a flat piece of wood or a piece of flat scrap metal) over the exhaust
hole, instead of needing another "half-bucket" to create the "retained heat
cooker" effect?  (If so, then that would also avoid the loss of heat when
removing the shield plus lid with exhaust hole, and no need to spend heat to
warm the new "half-bucket" top.)  This has worked well in my experiments 
with
my "retained heat cooker with pyro-booster".  And insulation (even a 
blanket)
will make it even better, but be sure there is no fire that could ignite the
blanket.

LH- Yep, the upper cap is not insulated so a  cover would help, and just 
plug the hole to shut down the stove for heat retaining mode.
Lanny Henson ....end

Looking forward to your reply.

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 lannych <lannych at bellsouth.net>:

> Stove Friends,
>
> http://bioenergylists.org/en/hensonbcs
>
> I have designed a simple and inexpensive stove that most any 
> dumpster-diver can build. This is a stove for someone who can't even 
> afford a pot, so if you are living in a developing area and you have no 
> income or you are a Westerner and you are laden with expenses (like 
> tobacco, drugs, alcohol, cell phone and cable bill.enough self criticism!) 
> and you just don't have the money for a pot, then this is the stove for 
> you.
>
> All you need is a Homeless Depot (construction site dumpster or land fill) 
> and you should be able to find the used metal containers you need to build 
> this stove for free.
>
> I did not pay much attention to the cosmetics of this early prototype but 
> who needs looks anyway.
>
> So meet me under the bridge, the pintos will be done about midnight!
>
>
>
>
>
> The Bean Can Stove is a $5 or less cooker including the pot.
>
> The Bean Can stove is made totally from used metal containers, (see 
> material list) even the cook pot.
>
> It is the simplest stove that I have designed requiring only hand tools 
> and no fab parts to build.
>
> It seems to be very efficient using only 152 grams of hardwood charcoal 
> and 5 grams of wood for starter to cook 2 lb/907gr of dry pintos. That is 
> 26 servings of 35gr ¼ cup dry ½ cup cooked, total volume 3.5 liters.
>
> The combustion air is controlled by elevating the stove with 3 sticks so 
> air can flow underneath.
>
>
>
> The soaked beans came to a boil at 33min after striking the match.
>
> Then I removed the spacing sticks to reduce the combustion air for 
> simmering.
>
> At 1 hour after initial boiling I could hear rapid boiling.
>
> At 1.5 hours I could hear slow boiling.
>
> At 2 hours I could still hear low simmering.
>
> The beans were cooked at this point (2 hours after boiling) so I capped 
> the system to retain the heat.
>
> And at 7 hours after boiling the temp was 150 degF/ 65.6 degC.
>
>
>
> I am very pleased with the ease of construction, use and the performance 
> of this cooker. It cooks 2 hours with little attention and holds for hours 
> more. That is long enough to be a bean or stew cooker.
>
> Next I plan to change the size of the burner so that the pot can sit lower 
> in the stove.
>
> Also this design could be adapted to use a typical cook pot instead of a 
> paint bucket, so I will test that.
>
>
>
> Material list:
>
> 3- 5gal metal pails and 2- lids, used $3.
>
> 1- one-gallon paint can with lid, used  (the cook pot) $1.
>
> 1- 1.13 liter/kg can used (burner)  ¢25
>
> 1- coat hanger  ¢10
>
> 1- fluffy ash or loose fill insulation. ¢25
>
> 4- sheet metal screws  ¢28
>
>
>
> Thanks for viewing,
>
> Lanny Henson
>
>
>
>
>
> See the photos at Tom Miles website, the link above or at later at 
> www.lanny.us
>
> Photo BC03
>
> Two pails make the inner and outer shell. There is a hole in the bottom 
> where the burner sits for combustion air.
>
>
>
> 02
>
> A center fire tin can burner holds 170 grams of high quality hardwood 
> charcoal. 5 grams of wood and some candle wax, top lights the burner. 18 
> gr of char did not burn. A little too much wax created some smoke.
>
>
>
> 04
>
> The lid supports the paint can pot just above the burner
>
>
>
> 06
>
> One half off a pail/bucket shields the cook pot.
>
>
>
> 07
>
> A lid with exhaust hole helps contain the heat.
>
>
>
> 10
>
> Very little heat escaped the system through the exhaust during the cooking 
> process.
>
>
>
> 08 09
>
> At 33 min I skimmed the pot and removed the spacing sticks to reduce the 
> combustion air for simmering.
>
>
>
> 11
>
> At 2 hours after boiling when the charcoal was consumed, I capped the 
> system with ½ of a pail which held the heat to 150 degF for 7 hours.
>
>
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>

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