[Stoves] The upside of Down feed

[rongretlarson at comcast.net]

Alex and list: 

This is to further explore the idea of char production in your device (which we should call??). 

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. 

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.) 

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? 

Might it make sense to replace the tall chimney in some circumstances with a blower? (To lower first costs - allowing a much shorter chimney?) 

Is this development related at all to backup heating of your greenhouse? Or manly intended for home heating? Any applicability to cooking? 

Ron 

----- Original Message -----
From: rongretlarson 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 





----- Original Message -----
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:) 

<blockquote>





<snip remainder> 

</blockquote>
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