[Stoves] Stratifying TLUDs for 'turn down'

[neiltm at uwclub.net]

On 14 Jan 2017 at 9:21, Ray Menke wrote:

> On Sat, Jan 14, 2017 at 8:07 AM,  <neiltm at uwclub.net> wrote:
> > not just involving varying moisture content but fuel
> > type and sizing also.
> 
> Neil, thanks for the report.  The burn pot on that stove is about 9 CM
> or a bit less than 4 inches, correct?  

Yes.  From bottom of fuel chamber to bottom of secondary air holes is 
3 1/8", and it is wider than deeper.

> I usually select my fuel from
> my various boxes (stashed around inside the house) too, although I
> work real hard to keep it all dry.  On the bottom, I sometimes use
> little charcoal brands, somewhat like torrefied wood, followed by
> slivers of mesquite or Huisache hardwood, and then red cedar on the
> very top as an ignitor.  This gives me a good hot start that slows
> down as the flame front reaches the brands.  Sometimes I have to add
> more because the pot is so small.

Thanks for that, that is exactly the sort of variation with local 
conditions that I imagined would apply.  Hadn't thought of using char at 
the base, but it seems an obvious alternative to wet wood to prevent the 
end of batch flare up at least.  Probably because I mostly rely on the 
accumulation of this small char for running our BBQ in the warmer 
weather.

> Our local grocery store has some neat matches imported from Mexico.
> They are called "Maya", (500 cost 70 cents) and are cactus quills
> tipped with some sort of very flammable coating (a  small gob on the
> tip).  Really good, and much cheaper than the regular wooden strike
> anywhere matches.
> https://www.heb.com/product-detail/maya-matches-10-pack/1202239

Don't think we can get them in the UK.  I'm guessing from your woods that 
you are in S or SW USA?

> My serious cooking stove is much larger, with a 20 CM diameter pot
> about 1/2 Meter deep.  

Wow, is that something you made?

> If I plan to BBQ some meat, I run the stove
> through a batch of hardwood slivers cooking potatoes, rice, boiling
> eggs, and heating water which overall takes at least 45 minutes, then
> I dump the glowing char into a small wood forge, turn on the blower
> and set the speed with a PWM hooked to an old motorcycle battery.
> Then I set the grill in place, and once it is hot, load on the steaks.
> I can vary the heat with the speed control, and even add a few raw
> mesquite slivers for some smoke flavor.  Dear wife says it makes the
> best BBQ ever!

Sounds like a lovely set up.  I have a pot bellied cast iron BBQ which I 
'turbo' with an old computer fan cased in a home made shroud placed in 
the draught aperture in the belly, running off a 12v battery when it 
needs some air pushed through the fine char.  It takes about 2 minutes 
from lighting to being ready to cook, lighting the char from newspaper in 
the base under the grate.

> The forge is a home-made copy of the Whitlox wood-fired unit, which is
> basically some firebrick arranged in a Vee, with a slit at the bottom
> where an iron pipe with four holes can blow air upwards through the
> charcoal made in the TLUD stove.  As soon as the food is done, I use a
> small shovel to recover the charcoal which I put into a large pan of
> water.  After it is dry, I brush it over hardware cloth.  

I place mine in a metal biscuit tin and pop the lid on to exclude the 
air.  It cools very rapidly with little loss.  When full I use a riddle 
(garden soil seive) of fine mesh to lose the ash and very small fines, 
usually straight onto the vegetable garden.

> The fines go
> into the garden compost pile, and the larger stuff gets tossed into my
> charcoal grinder with other charcoal, to be screened again (after
> grinding) and saved as fuel to be used in my charcoal gasification
> units that make electricity.

Brilliant.  You must produce a lot more char than I do!

Best wishes,   Neil

> Raining here too...
> 
> 
> 
> -- 
> Ray  Menke