[Stoves] Stratifying TLUDs for 'turn down'

[Mangolazi]

Hi Neil, 

I've also had success with making half-boiled eggs for breakfast using TLUDs :) Glad to hear of people using those stoves for real world cooking beyond the lab. My small tincanium stove boils water in about 10 minutes and the remaining heat from char is enough for another 10 minutes of quick frying. I try not to run it on char too often because it wrecks the housing. 

I'm using dried peanut and walnut shells, they're light and make a roaring flame when packed in tightly. Any problems with smoke when using wet wood at the bottom of the pile? 

There's a lot of optimization that can be done on these small stoves. I've never had a soot-free burn though. You could try adding a cross draft bar or a flame disk like on kgharris' designs to better mix pyrolysis gasses and secondary air for cleaner burning.


On January 14, 2017 10:07:17 PM GMT+08:00, neiltm at uwclub.net wrote:
>Just had to share an almost comically successful breakfast cook this 
>morning of porridge, done under an umbrella because of that immaculate 
>timing of rain starting just as I've got the stove lit, coincidence
>that 
>is only matched of course by rain starting the instant all the washing 
>has been put on the line!
>
>I cooked oat porridge, which simply involves bringing the oats and 
>milk/water to the boil and then simmering for 5 minutes while
>constantly 
>stirring to prevent burning.  (Burnt porridge is not nice.)
>
>What I wanted therefore was for the stove to bring the pan to the boil
>as 
>quickly as possible and then turn itself down at that point and simmer
>on 
>a lower flame for 5 minutes.
>
>The wood outside by now is sodden, when not actually frozen, but I
>still 
>put a bottom covering layer of it in the Chinese wood gas camping
>stove, 
>then progressively reduced the amount of wet wood in relation to 
>perfectly dried wood from off the top of our boiler, finishing off the 
>top third with dry wood only, for a good hot fire for the boiling
>stage.  
>This I achieved to match in cooking time and performance what I would 
>have achieved indoors on the gas stove, maybe even better.  I've boiled
>a 
>full kettle in 10 minutes in TLUD mode from striking the match with
>this 
>stove - it doesn't hang about getting going if the wood is dry.
>
>No sooner than the pan had boiled, the flames licking up the sides of
>the 
>pan disappeared bang on cue to give me my simmering flame.  Still a 
>little more vigorous than I would have set on a gas stove just to begin
>
>with, but not a problem and it settled down very nicely for most of the
>
>simmer.  I will have to see if I can achieve more abrupt transitions 
>successfully.
>
>When I took the cooked porridge off the flame I could see that there
>was 
>pyrolysis still going on right at the bottom, it was as if a flame from
>
>the bottom was working its way up through the glowing char above it,
>but 
>the net result was a lovely simmer fire without the flare up at the end
>
>typical of a uniform loading of TLUDs.
>
>Now I'm only a dilletante with these stoves, a regular/occasional user 
>when I feel like it, which is usually whenever the weather isn't too 
>horrible.  But although I will be honest and allow a margin for luck, 
>because I don't always get it right, I did achieve what I set out to 
>achieve for the cook.  It was only relatively recent experience of
>having 
>loaded stoves this way quite a few times by now that gave me this 
>control, so it occurs to me that where a cook is using these stoves all
>
>or the majority of the time, no matter what their local conditions and 
>found fuel available, they will clearly be able to apply accumulated 
>experience of the stove, the variability in their available fuel and
>what 
>they commonly cook, to knowing just how to get the fire they want when 
>they want it, even out of a fixed air ratio configuration stove, in a 
>variety of ways, not just involving varying moisture content but fuel 
>type and sizing also.
>
>This is control that is potentially available with the simplest of
>easily 
>fabricated tincanium stoves, requiring little more than a sharp point
>to 
>make holes in tins.  At that level it is also possible to make a
>variety 
>of stoves more suited to some specific cooking tasks with commonly 
>available fuel than others.  Given the extent to which A TLUD stove is 
>batch burn only, and the extent to which cooking tasks are repetitive,
>it 
>is potentially easy to make these stoves optimally for such repetitive 
>cooking tasks, and this I have done.  The only down side of the chinese
>
>ebay stoves is that it is not usually possible to limit the primary air
>
>sufficiently to prevent soot on the pan, but on the plus side, TLUD
>mode 
>can be just a really great start to an indefinitely sustainable burn 
>through continuing feeding the fire, a stage which also brings new ways
>
>to control the level such as allowing ash build up to partially choke 
>primary air, or simply putting more or less wood on the fire.
>
>I find pleasure and satisfaction in my own learning about woods and
>their 
>preparation, and building the kinds of fire that I want, that I find
>hard 
>to imagine is not potentially universal, even where there is no choice
>of 
>fuel type for the cook. It is a satisfying learned skill. We are a 
>perverse species in many ways.  Where there is third world poverty
>forced 
>to burn biomass there is aspiration for lpg and electricity. Where
>there 
>is first world wealth there is status amongst the wealthy rural
>dwellers 
>in the UK in their 'Aga' range combined cooker, oven and water heater 
>burning wood. Plus there is a growing interest in outdoor cooking on 
>wood, wood burning ovens for bread and piza, even amongst caterers at 
>festivals etc where the novelty (and taste) of cooking on wood pulls in
>
>the punters. In other words there is nothing intrinsically inferior to 
>cooking with biomass, the differing statuses assigned to doing so 
>depending on choice or its lack.
>
>Poverty in the UK is a relative term to third world poverty, but the UK
>
>poor who experience 'fuel poverty' and therefore scarcity at the point
>of 
>feeding pound coins they don't have enough of into gas and electric 
>meters do sometimes choose to install wood burning stoves for cooking, 
>space and water heating where a chimney is available, because there is 
>usually no shortage of free wood to be found whether in urban or rural 
>areas.  A second hand 'Rayburn' can sometimes be had for free, it being
>a 
>cost in transportation and time to dismantle these heavy cast iron
>stoves 
>where not wanted.  This depite their continued availability and 
>desirability brand new, and at a high price.
>
>Neil Taylor, in a sodden semi frozen England.
>
>
>
>
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