[Stoves] gas wick, first try

[Jock Gill]

Julien,

Thanks for pushing this experiment along.

A few notes to consider inserted below.

Cheers,

Jock

Jock Gill
P.O. Box 3
Peacham,  VT 05862

Cell: (617) 449-8111

google.com/+JockGill

:> Extract CO2 from the atmosphere! <:

Via iPad

> On Apr 5, 2014, at 2:46 PM, Julien Winter <winter.julien at gmail.com> wrote:
> 
> Hello Jock et al;
> 
> I have had a go with the two washers method, without the copper pipe in between them. 

Are you getting flamelets yet or still flames?  In my view flamelets will give yo  cleaner results.

The pipe in the middle is key to improving mixing and shaping the combustion chamber.  I strongly recommend you use one.  Geometry matters.

> What I observed was that some of the flames came up the sides and didn't mix well. 

See above.  Also consider:

What was the gap between the outer wall of the reactor and the edge of the disks?  Too small?  Too big? just right?

I find flames that creep up the wall indicates a too rich mixture -- ie not all of the fuel is consumed in the chamber.  So you might try more secondary air or less primary or both.  You only need enough primary air to establish the pyrolysis and establish a good draft in the start up phase - perhaps 10 - 12 minutes..


> So what I did was put the a concentrator lid back on (See attached photo). Now what I have is:
> 
> 1) top washer in the chimney
> 2) concentrator disk
> 3) bottom washer below the secondary air jets, but above the fuel bed.
> 
> With the concentrator disk, the flames are forced into the middle as before, where there is mixing, but then forced apart again as they pass the upper disk.

This could work, but I prefer a central column over a concentrator.
> 
> What concerns, me though is that the increased resistance to air flow has reduced the power output from the stove.

In many cases, the dirtier the burn, the hotter the fire.  It is a fine balance to achieve a tuning that burns cleanly and delivers a reasonable amount of "power", or thermal energy, to the target.

Removing the concentrator will likely increase the draft, less resistance, and thus increase the rate of pyrolysis = increase the thermal energy output.

> 
> Tomorrow, I will run some reps with and without the gas wick gizmo to measure the rate of fuel consumption.

I doubt this will tell you much as you will have changed far too many variables to get meaningful data.

In a day or two I will post some initial results from a FXJ burner that has ~ 12 cm disks with a 7.5 cm high combustion chamber.  No idea if this the optimal height.  The central post is about 2 inches in diameter -  a piece of steel pipe.  The reactor is 15 cm in diameter with a height of 19 cm.  I expect there may be an optimal ratio of the diameter of the center post to the diameter of the reactor.  Perhaps 1:3  Needs testing.

Keep up your experimenting and have fun too.

Cheers,

Jock


> 
> Cheers,
> Julien
> 
> -- 
> Julien Winter
> Cobourg, ON, CANADA
> <DSCN2215 - small.jpg>
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