[Stoves] Olivier Char-making Stove

Tue Aug 9 01:35:48 CDT 2011

Ron,

The secondary air rises up between the reactor and the burner housing.
The flow of secondary air is not assisted by the fan in any way.
The fan only supplies primary air.

Then the secondary air hits a horizontal plate where its flow is changed
from vertical to horizontal.
The horizontal plate runs from the outer wall of the burner housing right to
the edge of the outer holes.
The horizontal plate of the burner housing is situated 6 mm above the
burner.
It is easy to lower or raise this gap.
The holes of the outer ring and the inner ring are staggered.
Thus the secondary air has a theoretically clear path to both sets of holes.
Note that the gas exits the reactor from both the inner and outer holes of
the burner.
Why flames to not appear right above the burner holes is puzzling.
Each flame appears in the middle of a triangle - that is, between two outer
holes and one inner hole.
Therefore it is hard to understand how the secondary air reaches the one
inner hole in this triangle
since there is a flame right in its path.
See here the latest design on the burner and burner housing:
http://dl.dropbox.com/u/22013094/140%20Gasifier%20Jpegs/140%20Gasifier%20Jpegs/001.jpg
http://dl.dropbox.com/u/22013094/140%20Gasifier%20Jpegs/140%20Gasifier%20Jpegs/002.jpg

The original flame pattern in the burner design I inherited from Belonio
looked like this:
http://dl.dropbox.com/u/22013094/150%20Burner/IMG_0252.JPG

Prior developing the concept of a burner housing,
I tried several burner designs where secondary air is mixed with the gas
prior to combustion.
So instead of this:
http://dl.dropbox.com/u/22013094/150%20Burner/IMG_0444.JPG
I got this: http://dl.dropbox.com/u/22013094/150%20Burner/IMG_0398.JPG
Not very good.
All similar efforts to premix failed.

About your question regarding the turn down ratio,
I can turn down the fan where the flame height is about a half inch.
I can turn it up to where the flames height is about one foot.
But it is not wise to operate a gasifier at such a high speed.

The equipment cost per kW of $3.00 is not a typo.
As the reactor gets bigger, the equipment cost drops.
In many gasifiers with remote burners,
this $3.00 per kW would be simply the cost of a remote burner with its
pipework, fan and gas cooling equipment.
I can easily imagine large TLUD gasifiers of a 2-meter diameter and a
4-meter height.
It is just as easy to light and start-up a large gasifier as a small one.
In less than 30 seconds one can empty, reload and relight a gasifier.
If one cannot be down even for 30 seconds, more than one gasifier could be
employed.
As I explain in my paper, the one reactor can serve as a dryer, a gasifier
and a heat exchanger
without having to touch the reactor or empty it to fulfill all three
functions.
The biomass is dried and gasified, and the char is cooled, without having to
move around any solids.
The fact that the gasifier is equipped with a removable fan makes it so easy
to fulfill these three functions.

Thanks.
Paul

On Tue, Aug 9, 2011 at 9:04 AM, <rongretlarson at comcast.net> wrote:

> Paul,  2 lists and several ccs:
>
>    Note I have changed the thread name.
>
>    I have viewed your several new jpegs - and again am impressed.  It looks
> different  (but much )the same.from your "esrla" site.  The quality of the
> flames looks excellent.  Have you been able yet to have any lab combustion
> testing?
>
>    A few more comments below
>
>
>
> ------------------------------
> *From: *"Paul Olivier" <paul.olivier at esrla.com>
> *To: *rongretlarson at comcast.net
> *Cc: *"Discussion of biomass cooking stoves" <
> stoves at lists.bioenergylists.org>, "Biochar-production" <
> Biochar-production at yahoogroups.com>, "Robert Taylor" <rt at ms1.hinet.net>,
> "Todd Hyman" <toddhyman at live.com>, "loren cardeli" <
> loren at agrowingculture.com>
> *Sent: *Monday, August 8, 2011 5:51:05 PM
> *Subject: *Re: [Stoves] Jatropha and its future
>
> Ron,
>
> It was great talking to you by phone this morning.
>
> We (four Americans living in Vietnam) are starting a company here in
> Vietnam call EPWT -
> that is, Empowering the Poor through Waste Transformation.
> The Content section of my old website (http://www.esrla.com/)
> will soon be transferred to the new website (http://www.epwt.net/).
>
>     *[RWL:  The old one is very informative (and varied).*
>
> Recently we made a lot of improvements in gasifier design,
> most notably, the addition of a burner housing to supply hot secondary air
> to the burner.
>
>     RWL:  It is a little more clear than in our phone conversation. Is
> the outer ring of holes the entry point for the hot secondary air, and the
> inner set of holes the exit of the pyrolysis gases?
>
>     For other readers,  Paul noted to me in phone conversation that the
> flame appears in between  each set of three holes.  It is a surprise to both
> of us why it should appear that way.  Any explanations?  (In a burning match
> the boundaries are all determined by the flow of oxygen molecules inward
> towards the outward moving escaping pyrolysis gases.   In most pyrolysis
> stove operation, we see the reverse - the oxygen molecules are moving
> outward from the center of the flame (into the larger volume of pyrolysis
> gases).  Here the flame shape/location doesn't seem to follow those simple
> rules.   In all cases, the emitted light must be (?) where the oxygen
> molecules meet the gas molecules.  Anyone seen this before?  Note both gas
> flows are being pushed by his blower/fan/
>
> This allows us to lower the flame to a simmer without danger of the flame
> going out.
>
>    [RWL:   Any estimate possible on this "turn-down ratio"  (maximum power
> level over minimum)? I think some might be able to get 3:1 - but that may be
> on high side.
>
> The jpegs were good - but at some point I hope to see cutaways.
>
>
> Here is the 150 gasifier in operation with the new burner housing:
> http://dl.dropbox.com/u/22013094/150%20Burner/IMG_0444.JPG
> http://dl.dropbox.com/u/22013094/150%20Burner/IMG_0445.JPG
> Here is the 250 gasifier in operation with the new burner housing:
> http://dl.dropbox.com/u/22013094/250%20Gasifier%20Jpegs/IMG_0523.JPG
> Here is a picture of the same 250 gasifier with the new burner housing:
> http://dl.dropbox.com/u/22013094/250%20Gasifier%20Jpegs/IMG_0513.JPG
> Take a good look at this picture 0513.
> Note the small fan that powers this gasifier.
> It is no bigger than 40x40x28 mm, and is actually too strong for this 10 kW
> gasifier.
> We operate it at less than 10% of its wattage.
> I will soon be testing this fan to see if it will power the 500 gasifier.
> The 800 gasifier (with an output of up to 100 kW) will require no more than
> a 60x60x38 mm fan.
> The equipment cost of the larger gasifiers is less than $3.00 per kW.
>     [RWL:  At first I thought this was a typo.  PV is today about 1000
> times more costly.  (not a fair comparison of course).
>
> We will be starting the mass production of gasifiers quite soon.
>     [RWL:  There are not many Biochar equipment manufacturers able to say
> this.  It is great to see this sort of Biochar news this year.
>
> Many thanks.
> Paul
>
>     [RWL:   More thanks to you  - and in advance for the questions above.
> Ron
>
>
> On Tue, Aug 9, 2011 at 4:29 AM, <rongretlarson at comcast.net> wrote:
>
>> Stove List: and (added) biochar-production list and adding Robert and
>> (inventor?) Paul
>>
>> 1.  Thanks to Robert Taylor for alerting us to a competitor to the
>> Jatropha - the Chinese Tallow.  This plant was new to me - and a plant that
>> looks very interesting (somewhat dangeerous as an invasive species).
>> Apparently in part successful because the Chinese cultivated it and improved
>> it over thousands of years.  I think we can well see much the same for many
>> other species -and maybe especially Jatropha.
>>
>> 2.  On  the ESRLA site recommended by Robert,  I found an excellent long
>> paper also by Dr. Paul Olivier on a really nice looking TLUD stove being
>> manufactured and sold (apparently) in Viet Nam.   The paper is at:
>> http://esrla.com/pdf/landfill_06.pdf.
>>
>>   There is a strong case made there for using a fan - and Paul may well be
>> correct.  We should all look more carefully at the advantages of a blower -
>> in saving on fuel costs, but also on convenience and efficiency of being
>> able to control the blower speed.  There is a fine looking blue flame in one
>> picture.   But mostly I like the professional look and excellent prices on a
>> whole series of models - showing nice economies of scale in pricing.
>>
>>   I was in Viet Nam earlier this year and am not surprised at the high
>> quality and low costs of commercial products such as are demonstrated in
>> Paul's paper.  Their economy is really growing rapidly - and we in the USA
>> are mostly not aware of this big progress..  The Vietnamese are not a
>> typical Communist country - and especially the area in the South around Ho
>> Chi Minh City (HCMC - formerly Saigon).   Let's all pull for the Vietnamese
>> to beat out China in the Biochar race!
>>
>>    His design is very tall and thin - which surprised me.  I would like to
>> know if he has also striven to (or could) get a low squat stove.  Most
>> unusual of all is that he places a special burner on top of the unit after
>> top-lighting.  I have not seen that before.either
>>
>>  I hope that Dr. Olivier can add some details on his development of this
>> stove, how sales of these TLUDs are going, any problems with any of the
>> fuels he has been using,  and also if he has any results from the use of
>> Biochar in the field (improved yield, etc).  He makes a very strong case for
>> the economics of using rice husks and rice straw.  I also wonder if the
>> Tallow tree fruit (or branches) has been tested in this stove.
>>
>>    Congratulations to Dr Olivier for two excellent papers.  They bear
>> reading twice.
>>
>> Ron
>>
>> ps   After writing the above,  I had a substantial phone conversation with
>> Paul (he in Vietnam with a Louisiana phone!).  I am even more impressed -
>> and will try to learn more from some other leads he gave.  I look forward to
>> further remarks soon from Paul on his pyrolysis stoves - that have some very
>> clever stove innovations and some likely near-term commercial advances..
>> ------------------------------
>> *From: *"Robert Taylor" <rt at ms1.hinet.net>
>> *To: *"Discussion of biomass cooking stoves" <
>> stoves at lists.bioenergylists.org>
>> *Sent: *Monday, August 8, 2011 2:13:01 AM
>> *Subject: *Re: [Stoves] Jatropha and its future
>>
>> Here are some ideas about the Chinese tallow tree (Triadica sebifera, syn
>> Sapium sebiferum) from Dr Paul Olivier, who used to post to this list:
>>
>> http://esrla.com/pdf/tallow.pdf
>>
>> Robert
>>
>>
>>
>>
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>>
>>
>
>
> --
> Paul A. Olivier PhD
> 27C Pham Hong Thai Street
> Dalat
> Vietnam
>
> Louisiana telephone: 1-337-447-4124 (rings Vietnam)
> Mobile: 090-694-1573 (in Vietnam)
> Skype address: Xpolivier
> http://www.esrla.com/
>

-- 
Paul A. Olivier PhD
27C Pham Hong Thai Street
Dalat
Vietnam

Louisiana telephone: 1-337-447-4124 (rings Vietnam)
Mobile: 090-694-1573 (in Vietnam)
Skype address: Xpolivier
http://www.esrla.com/
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