[Stoves] Charcoal burning in stoves

Sat Dec 30 14:48:50 CST 2017

Hi Neil and Paul,

Thank you very much for that detailed description!

That is a very good use of charcoal fines. I was chatting with an old
charcoal seller near Mt Kenya the other day and he was telling me that he
sells many grades of charcoal (various sizes/prices of char for clothes
irons, maize roasters, blacksmiths, soup boilers, home cooks, restaurant
grade etc.) as well as seasonal blends of different types of charcoal made
from different types of trees. Which he can sell either as fast lighting
slow burning mixes to cooks, or higher ratio slow burning charcoal for soup
sellers etc. Some restaurant chefs he said like the flexibility of light
weight charcoal for faster service during lunch time rushes but still buy a
bag of hardwood large charcoal for slow cooking beans during the day. The
very fine charcoal dust that was left has now found a market as a soil
amendment and he was selling for about 3$ for a 50kg bag.

With our charcoal making drum kilns, we try to advise people to treat
charcoal much like how you are describing, just like with any fuel there
are various grades...so for fast cooking things like eggs or rice, use
maize cob or light twig charcoal as the 'high octane/V-Power' fuel mix, for
low and slow goat ribs or maize and beans type cooking, larger hardwood
lump charcoal from bigger branches blended with lighter twig char is better
for a long slow burn. We are finding that more of our customers are
appreciating the flexibility of using different types of woody biomass to
get the fuel best suited for the job at hand.

A few questions if I may;

*''I usually start with enough fuel for a half hour cook before needing to*

*add more fuel.  Because it is only a fairly small BBQ, (14inch
diametergriddle), I usually cook in batches, adding more char each time.
If I'mcooking chicken joints from raw I aim for about 40 minutes which is
easyto achieve on one loading. There seems little point in trying to
controla thicker layer for a longer time than the food needs to cook, so
eachbatch of food gets its own fresh layer of fuel. '' *

Do you find when you add more charcoal it smokes quite bit or not so much?
How much do you add usually, do you bank it to have a hotter and cooler
side of the fire? Do you have much fire left over once done?

It's still amazing to me to see, especially in hot places in Kenya, how
many times once someone is done cooking, they leave the stove lit,
unattended and not cooking while it dies down...all the while there is
enough usable heat left in a typical ceramic charcoal stove to bake 2-3
sweet potatoes or whatever tandoori oven style just as it cools.

*''I can do some measurements and photos when the warmer weather comes if
it*

*might be of any interest.  I've had this BBQ for 25 years now, so its
afamiliar tool that I am nicely attuned to, and the design
persists,although as I said I couldn't find it on ebay.com
<http://ebay.com/>, only .co.uk <http://co.uk/>.''*

Yes please do send photos, I at least would like to see it in action!

Best wishes,

Teddy

Teddy Kinyanjui
Sustainability Director

             <https://www.facebook.com/CookswellJikos>
<https://www.instagram.com/cookswelljikos>
<https://twitter.com/cookswelljikos?lang=en>

On Sat, Dec 30, 2017 at 6:35 PM, Paul Anderson <psanders at ilstu.edu> wrote:

> Dear Neil,
>
> That is a marvelous report on practical BBQ cooking with charcoal
> fines!!!!    I look forward to the photos.  And to any reports from other
> people who might replicate your rather distinctive charcoal BBQ cooking
> method.  I will probably do some experiments that relate to your reported
> experiences, but in the context of alternative TLUD stove structures.
> THANKS!!
>
> You remind me of Paul van der Sluis, the Dutchman who did the "pyroneer"
> work that became the Philips FA gasifier stove.   He too is an avid and
> frequent cooker.   And also of Ray Menke in Texas where he cooks with TLUDs
> for mnay years.   The three of you have a shared situation:  relavtively
> mild climate that lets you cook outdoors for many many months of the
> year.   (Right now in Illinois there are 15 cm (6 inches) of snow on my
> backyard.  Plus, I am not handy as a cook.)
>
> To avoid the initial smoke, I recommend seeking an alternative to paper.
> Maybe some charcoal lighter fluid or alcohol on a dense pad of steel-wool
> or on some of the same charcoal fines but placed below the grate so that
> the fan can do its job.   If you try something, please let us know.
>
> Paul
>
> Doc  /  Dr TLUD  /  Prof. Paul S. Anderson, PhD
> Email:  psanders at ilstu.edu
> Skype:   paultlud    Phone: +1-309-452-7072
> Website:  www.drtlud.com
>
> On 12/30/2017 6:22 AM, neiltm at uwclub.net wrote:
>
>> On 29 Dec 2017 at 9:52, Paul Anderson wrote:
>>
>> Neil,
>>>
>>> On 12/28/2017 4:54 PM, neiltm at uwclub.net wrote:
>>>
>>>> With very fine char such as the TLUDs produce, I re-use the mesh
>>>> scavenged from other peoples discarded disposable BBQ trays doubled up
>>>> across the grate to retain the fines.  Lit with a couple of sheets of
>>>> newspaper, and an old computer fan to augment the draft, we are cooking
>>>> in under a minute of striking the match.
>>>>
>>> I understand the grate and the char placement.   What are the walls like
>>> in this charcoal burner?
>>>
>>> What is the thickness of the char layer (because some air needs to be
>>> able to pass upward through the char, riight?
>>>
>>> Yes. I've never measured, which would be difficult given very varied
>> sized pieces of char, but little more than is needed to cover the grate
>> generously, so say an inch/ inch and a half, with larger pieces poking up
>> above that.  My reason for coming up with the fan in the first place was
>> experiencing too much ND draft restriction with the fine char, but mostly
>> it is needed only for quick starting, adding fuel, and occasionally as a
>> boost, more so if I am starting with a thicker layer, and sometimes to
>> get the last gasp out of an exhausting layer more quickly.
>>
>> Is the ignition paper under the grate?
>>>
>>> Yes, that's right.  There is a small sliding door to regulate the draft
>> which I made a sheet metal 'funnel' to (push) fit, with the computer fan
>> at the other end, running off any old 12v car battery.  This ensures a
>> rapid and complete combustion of the paper, and immediate and even
>> ignition of the char.  For about 30 seconds the billowing white smoke
>> looks as if I'm announcing the election of a new Pope before all rapidly
>> settles down to a smokeless burn.
>>
>> How long wiill it burn (in relation to thickness of layer?   or to
>>> weight?   or what else?)
>>>
>>> I've not done any weight measurements, but I find it hard to imagine a
>> more fuel efficient BBQ.
>>
>> I usually start with enough fuel for a half hour cook before needing to
>> add more fuel.  Because it is only a fairly small BBQ, (14inch diameter
>> griddle), I usually cook in batches, adding more char each time.  If I'm
>> cooking chicken joints from raw I aim for about 40 minutes which is easy
>> to achieve on one loading. There seems little point in trying to control
>> a thicker layer for a longer time than the food needs to cook, so each
>> batch of food gets its own fresh layer of fuel.
>>
>> This is all made easier by the excellent control I have over the fire,
>> whether by entirely regulating the ND with the sliding 'door', or if
>> needed, occasionally bringing the fire up with the fan, usually only in
>> short bursts or for getting the flames to quickly break through a new
>> layer of char.  In addition to these options, there are 4 heights at
>> which the grill can be held above the fire.  Mostly I aim not to have
>> flames licking around the food, and if things get too lively are brought
>> back under control quickly by closing the draft off.  The heat is greater
>> at the centre and towards the back, so food is also moved around as
>> required.
>>
>> Any other comments that might be useful???
>>>
>>> The fine char in the mix definitely helps with rapid lighting and
>> establishment of a cooking fire compared with large lumpwood only.
>>
>> The issue is "combustion of charcoal that is NOT lump and is somewhat
>>> "fine" but not powder(?).
>>>
>>> Correct.  I use a fine riddle to remove the ash and char below the mesh
>> size which is approx 2.5mm sq hole size.  Obviously most of the char is
>> well above that sort of size, being the sort of mix you would expect from
>> a TLUD, rocket stove or open fire.  It's only the open fire char where I
>> ever need to break up some of the larger lumps.
>>
>> I can do some measurements and photos when the warmer weather comes if it
>> might be of any interest.  I've had this BBQ for 25 years now, so its a
>> familiar tool that I am nicely attuned to, and the design persists,
>> although as I said I couldn't find it on ebay.com, only .co.uk.
>>
>> Best wishes,   Neil Taylor
>>
>> Paul
>>>
>>> Doc  /  Dr TLUD  /  Prof. Paul S. Anderson, PhD
>>> Email:  psanders at ilstu.edu
>>> Skype:   paultlud    Phone: +1-309-452-7072
>>> Website:  www.drtlud.com
>>>
>>>
>>>
>>>
>
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