[Stoves] Yuri's retort

[AJH]

It was good to see Yuri posting again and A D Karve's response was a
welcome acknowledgement that a number of us had taken on board his
contribution.

On Thu, 06 Mar 2008 06:29:00 -0700, Thomas Reed wrote:

>The process of Yuri burns some of the biomass to create the heat for the 
>rest. 

Well yes, it burns the volatile proportion that is driven off by the
flame heating the retort but it preserves all the fixed carbon. The
cleanliness of this offgas burning will be down to the combustion
system but in principle it is still a high calorific value gas and
could burn as well as any secondary flame.
>
>In our Toplit Updraft (TLUD) stove and charcoal maker we burn the 
>volatiles in a much faster process.  I doubt whether most opeople 
>understand the difference, but it is much simpler and cleaner.

It's simpler and doesn't have the drawback of the heat exchange
through the retort walls but as it consumes fixed carbon to provide
its primary heat it is likely far less optimal than Yuri's retort as a
means of making charcoal. The retort will retain around 40% of the dry
wood as 80% fixed carbon char compared with at most 25% running down
to 0% for the tlud system, depending on moisture content. 

There is also some scope to cascade heat post the retort for other
purposes.

AJH