[Stoves] Natural draft TLUD turn-down

Wed May 21 12:37:19 CDT 2014

Crispin,

   Indeed this is quite useful info.  I knew about DD combustors and 
have also seen them in operation (at /Chip Energy/ in Illinois during 
"CHAB Camp" in 2010)... and have seen the way the char could be 
"extracted" from the 'base' of their gasifier "at just the right time" 
using a simple screw conveyor hooked up to one side of the gasifier 
chamber, prior to where the ash was pulled off ~ which also allowed the 
DD unit to operate at "full load" (complete combustion to ash) or in a 
'mode' that allowed for char take-off (at the user's discretion -- by 
simply turning off the char extraction conveyor).
   It was the type of system I would /probably/ be looking for, but on a 
somewhat smaller footprint -- since the /Chip Energy/ DD system was 
mounted inside a 20ft shipping container.  However my client has only a 
very limited amount of space (~4ftX4ft), and I also wanted to get more 
info about /other/ devices that may be out there (available on the 
market) before deciding on any particular technology. Do you know if All 
Power Labs <http://www.allpowerlabs.org/> has anything smaller than the 
"power pallet"? (As far as I know they also do not make their BEK 
anymore either.)

  Do you have more info about that "biomass burning DD stove /that/ was 
produced in Swaziland and test marketed around Johannesburg in 
2004-2005" and/or the "Wood burning BLDD 6" from Johannesburg?
   A website? Spec sheets? A key contact in Swaziland/Johannesburg? 
Pricing??

  My task right now is to bring forward and present three [3] 
char-producing technologies to my client so that we can review them and 
decide how to move forward based on the specifications, price, features etc.
  While we are only at the "information gathering stage", it would be 
good to have as mush concrete info as possible from as many technology 
providers as possible so that we can make an educated decision about how 
we will move forward (i.e. whether to purchase 'off-the-shelf' ~ if 
available ~ or to use some kind of 'open-source' plans to build a unit 
ourselves ... with the final decision likely coming down to the all-in 
cost -- including labour, shipping etc. etc.).

P.S. I don't need any info about the lignite-burning BLDD 3 (developed 
in Mongolia) since I doubt that we will ever be using/burning "50mm 
semi-coked briquettes".

P.P.S. Does anyone know info about Greg Manning?  I was once told that 
he had built a Downdraft 'rig' in Brandon, Manitoba that allowed for 
"unattended operation". Apparently he had developed an 800 lb "side 
bunker hopper" gasifier unit (with integrated Drying Process) that ran 
about 7lb/hr (of chips) for ~ 4 3/4 days (unattended).

--
P.P.P.S. Yes, it was a bit annoying to read so many (incomplete) 
messages in a row from you. It seems that "BlackBerry 10 smartphone" 
that you are using could probably use a bit more "software tweaking" for 
its 'virtual keyboard' so that users are not continually annoying their 
own clients/friends/family with unfinished (and repetitive) emails... 
[And I'm sure that you can find a way to let BlackBerry know about this 
'issue'. :-) ]

Regards,

   Lloyd Helferty, Engineering Technologist
   Principal, Biochar Consulting (Canada)
   www.biochar-consulting.ca
   48 Suncrest Blvd, Thornhill, ON, Canada
   905-707-8754
   CELL: 647-886-8754
      Skype: lloyd.helferty
   Steering Committee coordinator
   Canadian Biochar Initiative (CBI)
   CURRENTS, A working group of Science for Peace
   http://www.scienceforpeace.ca/currents/
   President, Co-founder & CBI Liaison, Biochar-Ontario
   National Office, Canadian Carbon Farming Initiative (CCFI)
   Organizing team member, 2013 N/A Biochar Symposium:
     www.carbon-negative.us/symposium
   Member of the Don Watershed Regeneration Council (DWRC)
   Manager, Biochar Offsets Group:
            http://www.linkedin.com/groups?home=&gid=2446475
    Advisory Committee Member, IBI
   http://www.linkedin.com/groups?gid=1404717
   http://www.facebook.com/group.php?gid=42237506675
   http://groups.google.com/group/biochar-ontario
   http://www.meetup.com/biocharontario/
   http://www.biocharontario.ca
    www.biochar.ca

"Producing twice as much food with diminishing resources, without further loss of natural habitats and biodiversity and in a changing climate may be the greatest challenge facing humanity."
    - Lloyd Helferty

On 2014-05-21 7:23 AM, Crispin Pemberton-Pigott wrote:
> Sorry for the tedious repetitions, I keep sending the message 
> accidently - virtual keyboard... :(
>
>
> Dear Jason and Lloyd
>
> The downdraft combustor can be very clean burn?ing, it is agreed. A 
> biomass burning DD stove was produced in Swaziland and test marketed 
> around Johannesburg in 2004-2005. It also had a retrofit combustor 
> that had an additional feature which was that the gas outlet was 
> angled. This allowed the insert to be rotated with respect to the 
> stove body sending the hottest gases directly against the side wall 
> for space heating or against the side of a sunken pot for high 
> efficiency cooking.
>
> I think it was the first DD stove that made a serious efforts to 
> implement the 'floating fuel' approach to the grate, the grate was 
> made from thin high temperature wire.
>
> The insert was conical at the bottom with preheated secondary air. It 
> is also possible to cook on the upper side of such a layout, something 
> incorporated into the BLDD stoves at the SeTAR Centre In Johannesburg 
> now at version 6. The Wood burning BLDD 6 can cook three pots at once.
>
> The BLDD 3 developed in Mongolia was tuned to burn lignite and was the 
> only stove available there in 2009 that could properly burn 50mm 
> semi-coked briquettes. The DD approach still has much unexplored merit.
>
> To make char with a DD stove requires removing it at just the right 
> time. It is easier to do that with a cross draft burner which is just 
> as clean and easier to light.
>
> Regards
> Crispin
>
>
> Jason,
>
>   I've taken a look at your website and the info about the 
> "IntensiFire", however one of the main points of the project will be 
> to produce biochar (for use with the compost that they are already 
> making).  If the IntensiFire is only meant to increase efficiency and 
> to reduce emissions for wooid burning stoves, this may not be quite 
> what we are looking for, although it might be possible to "adapt" the 
> IntensiFire to the application in some way [?] (in order to maximize 
> the efficiency and minimize the emissions) ~ although the total cost 
> might be quite prohibitive, given that the IntensiFire (Mk II) is 
> already starting at $499 NZD (not including shipping all the way from 
> NZ to Canada).
>   I will, however, keep your downdraft technology in mind as we move 
> forward with our project.
>
> Regards,
>    Lloyd
>
>
>
>
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