[Stoves] Fire Stump

[ajheggie at gmail.com]

On Sunday 17 July 2011 00:22:11 rongretlarson at comcast.net wrote:

>
> 3. It would be interesting to see if a TLUD design could be operated
> with a set of secondary air holes part way up. I don't think so - since
> the pyrolysis front drops to the bottom almost immediately. Then the
> combustion will mostly occur at the bottom. I think it would be almost
> impossible to make char with this design.

from what I saw I think the only reason the fire dropped to the bottom was 
the starter was pushed down the hole. I surmise that whether they would 
operate tlud would depend on the dryness of the log, The versions sold 
here in UK are mostly pine and kiln dried. Pine has a fair amount of 
resin and is not very dense, so easy to start. These are advertised as 
for top lighting. The moisture is important because the heat needed to 
drive it off is limited by the ability of the descending pyrolysis front 
to provide it. From what we have seen this is nearly all provided by 
burning residual char such that at about 30% mc all the char is needed, 
above that tlud is not sustained which is why some of the videos show the 
fire as a bottom fired updraught.
>
> 4. There are sawdust stoves (sometimes called Boy Scout??) that operate
> similarly (to the central hole design). Dr. Priya Karve did some nice
> theoretical/experimental work on such.

Again these can be top lit as long as the hot char doesn't fall to the 
bottom
>
> 5. No one talked about the great efficiency of the Kelly Kettle -
> because the flame is going up the center.

I use a kelly kettle because it also acts as a chimney but I would debate 
the greater heat transfer efficiency compared with a pot with a well 
designed skirt.
>
> 6. I wish I had seen how difficult it was to drill the central hole of
> the Rocket design. Is there a power tool on the market like the chain
> saw (but for drilling holes)?

There are a number of attachments for a chainsaw but it isn't difficult to 
plunge cut with a chainsaw to create a vertical star which gives more 
surface area than the hole.
>
>
> 7. This is way off topic - but there was great long video dubbing a
> 1930 film of logging at:
>
> http://www.youtube.com/watch?v=cIKCjQdxtO0&feature=related

Amazing hard work, risks and skill. Those lunches must have been about 
5000 calories and the only fat men were the bosses. I wonder what the 
life expectancy of a lumberman was and I bet they didn't get overtime pay 
for that 4:00 till dusk shift?

I cannot believe that lumber was grown in 27 years.

AJH