[Stoves] The upside of Down feed

[Alex English]

Ron,

On 24/01/2012 12:35 PM, rongretlarson at comcast.net wrote:
> Alex and list:
>
>    This is to further explore the idea of char production in your 
> device (which we should call??).
We could call it the thinking-outside-the-box-stove stove:)  Suggestions?
>
>    In the exchange below, I think I have to side with Crispin - is not 
> the fuel essentially all combusted?   Of course it is the usual 
> two-step combustion - with pyrolysis first leaving a pile of char - 
> which is then itself more slowly combusted?   As the char disappears, 
> more pellets are able to fall down.  You seem to have established 
> stable rates of pellet and air flows such that the pyrolysis zone is 
> unable to travel up into the hopper.
A combination of forces are moving the pellets down and over while they 
burn, completely.
>
>    The Venturi effect you mentioned is one drawing both pellets and 
> air down from the hopper - yes?   (When I wrote yesterday I was 
> fixated on char movement.)
No, the venturi is the shape of pile at the end of the grate. It is not 
a functioning venturi. The chimney effect draws the air.
>
>    My reason for still pursuing the char production possibility is 
> that your geometry seems very similar to the Dasifier (concept of Agua 
> Das - being ccd).  Das tells me he can produce char.  Somehow your 
> grate has to be replaced by one that allows char to fall through??   
> Is there any alternative then to an auger?
Air and gravity may be able to move the char enough to create a 
continuous flow. As the pellets lighten during charring they are more 
subject to the force of moving gasses. A bit f a long shot, but possible.
>
>    Might it make sense to replace the tall chimney in some 
> circumstances with a blower?  (To lower first costs - allowing a much 
> shorter chimney?)
Yes.
>
>    Is this development related at all to backup heating of your 
> greenhouse?  Or manly intended for home heating?  Any applicability to 
> cooking?
No No this is pure science:)  My first choice is to succeed with wood 
chips as they are cheap and available and cordwood and chainsaws has 
taken a toll on my old tendons and ligaments. Combustion processes are 
adaptable to local needs and circumstances. I won't predict how they 
will be used. I used Tom's TLUD camp stove to heat phosphoric acid to 
clean a copper heat exchanger at the greenhouse last fall. It was 
perfect for the job. Who'd a thunk.

Alex








Ron
> ongretlarson at comcast.net
> *To: *"Discussion of biomass cooking stoves" 
> <stoves at lists.bioenergylists.org>, "Alex English" <english at kingston.net>
> *Sent: *Monday, January 23, 2012 9:38:55 PM
> *Subject: *Re: [Stoves] The upside of Down feed
>
> Alex and list:
>
>     My interest is in the first several lines, which read:
>
> Crispin:   "This is interesting news. The grate looks great, and if 
> there is a pile of char that is maintained in front, we must conspire 
> to burn it."
>
>
> Alex:  "Not so fast. I rather like the idea of a naturally formed  
> biochar venturi:)"
>
>
> RWL:   I have totally missed the possibility of a char output in your 
> design.   I can't even see a Venturi possibility..   Can you explain a 
> bit more on how that can be accomplished?   Have you accomplished any 
> char preservation yet?
>
> Thanks.    Ron
>
>
>
> ------------------------------------------------------------------------
> *From: *"Alex English" <english at kingston.net>
> *To: *"Discussion of biomass cooking stoves" 
> <stoves at lists.bioenergylists.org>
> *Sent: *Monday, January 23, 2012 6:45:36 PM
> *Subject: *Re: [Stoves] The upside of Down feed
>
> Dear Crispin,
>
> On 22/01/2012 10:36 PM, Crispin Pemberton-Pigott wrote:
>
>     Dear Alex
>
>     This is interesting news. The grate looks great, and if there is a
>     pile of char that is maintained in front, we must conspire to burn it.
>
> Not so fast. I rather like the idea of a naturally formed  biochar 
> venturi:)
>
>     <snip remainder>
>

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