[Stoves] Fwd: the 150 gasifier in operation in Vietnam
rongretlarson at comcast.net
rongretlarson at comcast.net
Sat Mar 3 17:58:42 CST 2012
Stovers:
This being sent per request from Paul Olivier.
Some new good information here. Credit given to Dr. Belonio . There have been a few other intermediate messages from Dr. Olviier.
Below, the inventor of the Pyromid stove should have been given as Paul Hait.(charcoal-using, highly reflective).
Ron
----- Original Message -----
From: "Paul Olivier" <paul.olivier at esrla.com>
To: rongretlarson at comcast.net
Sent: Saturday, March 3, 2012 1:43:28 PM
Subject: Re: [Stoves] the 150 gasifier in operation in Vietnam
Ron,
See my comments.
On Sat, Mar 3, 2012 at 10:36 PM, < rongretlarson at comcast.net > wrote:
Paul -
Maybe you hit the wrong "reply"? I think this additional data would be of considerable help to the full stoves list.
I meant to send it to the whole list.
Can you resend it for me?
I do not know what I did wrong.
<blockquote>
We don't pay enough attention to the heat transfer part of stoves. I would like to see a "Kelly kettle" (interior "flue") used with your new radiator/convector. Nat Mulcahy has a wonderful video showing how fast he can boil with such - faster than his microwave, he says.
If you get a chance to repeat, it would help many of us to try to compare the power levels through a bit more data: weight of propane consumed over some time period, amperage and/or wattage or kWh, and weight of rice husk consumed. The time element tells a lot - but there are other things going on (such as how high you can set your fan level).
</blockquote>
The idea of how fast it takes to bring a liter of water to a boil does not give a complete picture.
For example, it does not take into account the diameter of the gasifier or the speed of the fan.
I could turn the fan very low and surely it might take more than 12 minutes to bring a liter of water to a boil.
I already equipped my 250 gasifier with a burner housing and a wire mesh dome.
This gasifier puts out almost 3 times the power of the 150.
If I did a boiling test with this gasifier, this would surely be cheating.
Belonio did a boiling test with his 150 gasifier on one liter of water,
and he reported an average time of over 8 minutes.
I have the same reactor diameter and burner hole pattern as Belonio.
But I surrounded the burner with a burner housing,
and over the burner housing there is the wire mesh dome.
The housing draws in secondary air,
and a bit more secondary air is drawn in through the wire mesh at the base of the dome.
On the left you see the burner and burner housing,
and on the right you see the wire mesh dome:
http://dl.dropbox.com/u/22013094/150%20Gasifier/Boiling/IMG_1024.JPG
Here you see the burner, burner housing and the wire mesh dome assembled on top of the reactor:
http://dl.dropbox.com/u/22013094/150%20Gasifier/Boiling/IMG_1022.JPG
But the heart of my burner is the Belonio burner.
I have no idea how he got this right.
I changed the diameter of the burner holes by a half mm in both directions,
and this does not give a good result.
It must be 4.5 mm, just as Belonio specified.
Perhaps Belonio simply worked out the burner hole diameter and the pattern of holes simply by trial and error.
Also I changed the the air entry gap between the burner and the burner housing several times,
and this does not give a good result.
Gaps of 2 and 4 mm do not work.
But a gap of 6 mm works quite well.
I have no idea why this is so.
Now I am experimenting with the wire mesh of the dome:
with the diameter of the wire and the opening between wires.
If the aperture is too small,
I do not think that the draw of secondary air through the burner housing and wire mesh dome will function correctly.
If the aperture is too big,
the gas goes through the wire mesh and ignites on the outside of the dome.
When this happens, the wire mesh does not glow red hot.
Paul Anderson is at times impatient with me.
He says that I need to start selling rice hulls gasifiers as soon as I can.
But I do not think that I will ever have a gasifier that I will call my own.
I found a factory in Saigon that has started making molds to cut and press the various parts of the 150 gasifier.
I intend to sell these parts to any workshop that wishes to buy them.
Also I had to change the size of the grate holes.
And I finally found, what I think, is the best way to detach and attach the small 40 x 40 mm fan.
In the end I think that I will simply post fabrication drawings of the 150 gasifier on my website for all to use.
I received just about everything from Belonio, and I will in turn pass on what I have found to everyone else.
Here are some recent jpegs.
The burner and burner housing:
http://dl.dropbox.com/u/22013094/150%20Gasifier/Jpegs/013.jpg
The wire mesh dome on top:
http://dl.dropbox.com/u/22013094/150%20Gasifier/Jpegs/012.jpg
http://dl.dropbox.com/u/22013094/150%20Gasifier/Jpegs/006.jpg
The detachable fan:
http://dl.dropbox.com/u/22013094/150%20Gasifier/Jpegs/014.jpg
The complete gasifier:
http://dl.dropbox.com/u/22013094/150%20Gasifier/Jpegs/004.jpg
The gasifier set within an enclosure:
http://dl.dropbox.com/u/22013094/150%20Gasifier/Jpegs/008.jpg
Please share this email, if you wish, with the stove list.
Thanks.
Paul
<blockquote>
My modern electric stove has a radiant heat transfer through a tough "glass/ceramic" which is also conducting (not convecting [much]). We haven't been paying enough attention to that mode.
In the early days of the stove list, an entrepreneur (name forgotten) in Oregon, talked a lot of his "Pyromid", which paid a lot of attention to briquette placement and proper angles of highly reflective stainless sheet steel walls in a charcoal cooker. Not anything since that I can remember
I was also reminded of the use of the thin, flimsy mesh in gas lanterns. Maybe there is some way to change the frequency spectrum? You have raised a fascinating new topic.
Ron
From: "Paul Olivier" < paul.olivier at esrla.com >
To: "Ron Larson" < rongretlarson at comcast.net >
Cc: "Discussion of biomass cooking stoves" < stoves at lists.bioenergylists.org >
Sent: Friday, March 2, 2012 11:25:15 PM
Subject: Re: [Stoves] the 150 gasifier in operation in Vietnam
Ron,
See comments.
On Sat, Mar 3, 2012 at 11:04 AM, Ron Larson < rongretlarson at comcast.net > wrote:
<blockquote>
Paul and lists
Congratulations on the new design with a mesh. I think you have achieved the nicest looking flame yet of any stove ever described on this list.
</blockquote>
On February 22, 2012 I did three boiling tests.
The first test was carried out on a normal propane gas burner that I have in my kitchen.
http://youtu.be/w8OdW_GEhWo
Here it took 6 minutes and 6 seconds to bring one liter of water to a boil.
The burner shown in this video is a very efficient premix gas burner.
But since it operates solely by means of convection, its performance is not optimal.
The second test was carried out using the 150 gasifier:
http://youtu.be/jK3UTe1Lxqk
Here it took 3 minutes and 42 seconds to bring one liter of water to a boil.
Note that the same pan without a lid was used in these two boiling tests.
Here heat is transferred by both convection and thermal radiation.
The third test was carried out using an insulated electric water kettle, as shown here:
http://dl.dropbox.com/u/22013094/150%20Gasifier/Boiling/IMG_1042.JPG
Here it took 3 minutes and 25 seconds to bring one liter of water to a boil.
In this way I was able to compare the two previous results
with what could be considered to be the fastest way to boil water in a kitchen setting.
I wonder if you have found any technical design literature for this added radiative mesh? (Materials, wire diameters and spacing, etc?)
I have no theoretical understanding with regard to what is happening with the wire mesh dome.
I tried flat wire mesh, and this did not work at all.
The wire mesh has to be in the form of a dome to accommodate the small diffusion tail that you see here:
http://youtu.be/WXZvvoxCm1g
I tried wire meshes of various apertures.
If the aperture of the wire mesh is too big, the flames are not contained properly under the dome.
If the burning of gases takes place above the dome, the dome does not turn red hot.
This week I will experiment with much finer wires and apertures.
Also, if I turn down the primary air to a point where much less gas is produced,
combustion no longer takes place at the burner holes but within the apex of the dome.
Here a most unusual but stable cloud of burning gases is formed.
The wire mesh dome quite nicely protects the gas being combusted from disturbance by the wind.
Previously when the wind would hit the burner without the wire mesh dome, it would move the flames in all directions.
Often it left in its wake a lot of unburned gases.
I think that thermal radiation travels down to the burner and keeps it hotter than before.
I suppose that as hot gases hug the underside of the red hot dome,
gas temperature prior to combustion is higher than before.
The wire mesh dome not only emits thermal radiation,
but it also traps fine cinders that are emitted by the burner.
It will take many more months of experimenting and testing to understand a bit better what is happening here.
Thanks.
Paul Olivier
<blockquote>
To list readers, I strongly recommend the report given below, as well as the videos. There are some impressive Biochar field results as well as stove results. For this reason, I am also forwarding this to the (general) Biochar list.
Ron
On Mar 2, 2012, at 4:11 PM, Paul Olivier < paul.olivier at esrla.com > wrote:
<blockquote>
This is a TLUD forced air gasifier in operation on rice hulls.
Here you see the burner with burner housing:
http://www.youtube.com/watch?v=nZDt8DfgSls&feature=channel
http://youtu.be/WXZvvoxCm1g
When a wire mesh dome is placed on top of the burner and burner housing,
this roughly doubles the amount of heat being transferred to a pot:
http://youtu.be/7fnGem9BQ7Q
http://youtu.be/yO3jcbQj-GI
http://youtu.be/2c6A6BVitpE
Here it took 3 minutes and 42 seconds to bring a liter of water to a boil:
http://youtu.be/jK3UTe1Lxqk
http://youtu.be/80REBVTwpMo
For more details on this gasifier, see:
http://esrla.com/pdf/landfill_06.pdf
Thanks.
Paul
--
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/
</blockquote>
<blockquote>
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</blockquote>
</blockquote>
--
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/
</blockquote>
--
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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