[Stoves] Trials on TLUD gas burners + central cylinder

[Ronal W. Larson]

Paul, Julien, List

	Here is an idea that might be worth trying with what Julien already has available:   

	The central “buffer cylinder ” could be dropped all the way down to rest directly on the fuel bed. The bottom end of the cylinder should be closed - not open as in Jock’s work.   It should drop freely as pyrolysis causes the fuel bed to shrink.  It could be centered with 3 loosely-fitting longish screws top and bottom.  Not sure, but I think there is an advantage to having the “buffer” touch the charcoal

	There could be a way to get swirl using this “buffer cylinder”.  Maybe a heavy duty spring could be used  (both with and without bottom closure?)

	I have no idea what the right length of the buffer should be.

	The test could be run both with and without the washer-shaped concentrator below.  The test can be run with all of the A,B, C geometries I think.  

	I still have hopes for “A” (the “rectangular” - with no outer lower “washer” concentrator), but with the new “buffer cylinder” replacing the previous central lower blockage.

Ron	



On May 6, 2014, at 7:49 AM, Paul Anderson <psanders at ilstu.edu> wrote:

> Julien,    [And of interest to all TLUD stovers.]
> 
> Very nice experiment.   There are several variables to consider:
> 
> 1.  Increase the diameter of the central buffer cylinder
> 
> 2.  As the buffer cylinder gets wider, it will need to be raised slightly from the concentrator hold.
> 
> 3.  The buffer cylinder might be shorter (not up to the top of the riser, ie., the internal chimney that is below the pot).   That would allow the Venturi Effect to cause swirling back into the center of the riser.
> 
> 4.  Variations in the holes for the entry of the secondary air, such as smaller but more numerous, or with deflectors to cause the air to enter at different angles.   [ This is a bit more work because it requires making other "burners"/risers.    It is good that the main material is a common-size tin can.  ]
> 
> 5.  There is also the issue of the ConcAbove that should not be totally discarded without further experimentation.   There is evidence that having SOME (unknown amount) secondary air entering the fuel chamber (that is, below the concentrator) helps maintain the needed heat and the flame, giving additional buoyancy (push or thrust) to get the combustible gases to exit upwards through the concentrator.
> 
> 6.  Other variations that others can suggest.
> 
> At this early stage, it appears to me that the rectangular burner is not as likely to have good results as is the  ConcBelow design.  After a few more trials, it might be set aside. 
> 
> Also, I hope that several others Stovers will join in and replicate and expand upon what Julien is doing.   
> 
> I have also already discussed with Julien if he could attend the Stove Camp at Aprovecho on 21-25 July this year.   And even if he cannot, he and I will try to have the latest of the research about TLUD burner designs available at the Camp for some demonstrations and testing under the emissions hood.
> 
> Paul
> Doc  /  Dr TLUD  /  Prof. Paul S. Anderson, PhD  
> Email:  psanders at ilstu.edu   
> Skype: paultlud      Phone: +1-309-452-7072
> Website:  www.drtlud.com
> On 5/5/2014 9:27 PM, Julien Winter wrote:
>> Hi Stovers;
>> 
>> At the suggestion of Paul Anderson, I ran single tests on the burner with the concentrator below secondary air holes (ConcBelow), and the discontinuous annular (Rectangular) burner.  In these tests I put a 2.5 cm diameter cylinder in the center of the burners to direct flamelets upwards in the chimney.
>> 
>> A pdf is attached.  Photographic conditions were not ideal (nor was my old camera), but good enough to see how the flamelets were affected.
>> 
>> I can't say if the central cylinder was an improvement, because my soot test was not that sensitive.  However, the central cylinder didn't appear to increase soot production compared to having no cylinder, nor did it slow down the rate of gasification.
>> 
>> Future, more detailed experimentation could include a central cylinder to see if it reduces the mass of soot produces, and increases the rate of heat transfer to the pot.
>> 
>> Cheers,
>> Julien.
>>  
>> -- 
>> Julien Winter
>> Cobourg, ON, CANADA
>> 
>> 
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