[Stoves] Premix configuration

[alex english]

>
> Paul
>
> This leads to some questions.  Some are clearly for you to tell of your
> experiences.   Others are suggestions of what other people could do if they
> wanted to get involved in replication.  There are some variables (device
> characteristics) that are not stated, so this is not yet something that a
> casual observer would do without further understanding.
>
> 1.  Is you unit with forced primary air?
>
No. I light the fuel with a wide open 3 inch diameter primary air. Once it
is charring across the surface I add the burner and light the flame and
begin reducing primary air. With the flame in the video the opening might
be all of a centimeter square.

Please describe.  If not with forced primar air, is there additional riser
> (chimney) above the zone of ignited gases?
>
 Here is a pic of the pieces.
https://goo.gl/photos/MQ27RrMQuoFY2Qmy8
The two inch pipe acts as a chimney for the tlud fuel reactor. The six inch
pipe acts mostly as a chimney to draw secondary air. The secondary air
opening is essentially the circumference of the two inch pipe, one inch
wide. That is a cross sectional area twice that of the two inch pipe circle
opening, below it, which is providing the fuel.

>
> 2.  Is there any turn-down capability?
>
Yes. Turn up or turn down changes flame speed and the excess air. Total
control over primary and secondary air is something I have done. It should
be done by someone with the right test equipment. You can actually dial up
and down the CO, and I would like to see that linked with particle
emissions data. We sort of tried to do this at the stove camp last summer
with a different burner. It would work better with this one.

>   And if turn-down of primary air does occur, we would expect the zone of
> the ignited gases to be lower in the funnel, right?
>
Not if the flame speed of the mix is reduced more than the velocity is
reduced. The blue flame can rise up into the chimney and become a paper
thin sheet of blue.

>
> 3.  What might happen if there was forced secondary air?
>
You can remove the chimney. I have done it with other models.

>
> 4.  If a flame/spark was introduced at the point of the entry of the
> secondary air, what would happen?  .
>
That is how I light the flame. If the mix is right it can be lit from
above.You can quench the flame by choking off the secondary air. Open it up
and it lights itself from the hot metal.

> ..
> a.  a yellow flame upward in the funnel?
> b.  extinguished spark/flame (that is, no ignition)?
> c.  the flame goes up to the top and becomes blue without any flame lower
> down?
>
> 5.  How do you actually ignite the pre-mixed gases?  That is, when and
> where do you first ignite the gases that were shown in the video?
>
> 6.  Please comment on extending the narrow (2 inch diameter) section so
> that the blue flame would be even further from the entrance of the
> secondary air.   How far?   And if the diameter was even smaller, could the
> length be even longer?
>
Perhaps. Anywhere below the  flame and the metal cools you get some
condensing tarry liquids. They build up on the pipe and run down into the
chamber and are charred. Some heat recycling would reduce it.

>
> 7.  Have you experimented with sending the pyrolytic gases a longer
> distance before the entry of the secondary air?
>
No. The length was just enough to keep the pressure at the top of the fuel
chamber negative. Otherwise it would leak a bit of smoke.

Alex

>
> VERY interesting!!!!
>
> 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 9/29/2016 12:03 PM, alex english wrote:
>
> Paul,
> See below for a link to a picture.
> The gasses rise through a 2 inch diameter pipe which draws from a 12 inch
> diameter fuel chamber. Secondary air is introduced tangentially below the
> smooth funnel which expands to  6 inches. The picture shows that the high
> heat from the flame affects only the top of the funnel. So there is an 8
> inch + distance where premixing occurred and velocity exceeds the flame
> speed.
>
> https://goo.gl/photos/GB9PMaf6dX3n8cQ78
>
> See video by Alex:
> Here is a recent video of my premixed blue tlud-gas flame. Its all
> geometry, no obstruction.
> https://www.youtube.com/watch?v=jnV1e60NTss&feature=youtu.be
>
>
> Alex
>
>
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