axehandle - 19-1-2004 at 07:57
During my attempts to cool my NST-driven
NO2-reactor, I tried to keep it submerged
in distilled water, including the protruding
parts of the electrodes. The arc inside the
glass reactor would not, however, form.
I always thought distilled water was
completely non-condutive.
Am I wrong (the NST is AC, 9kV, 60mA)?
BromicAcid - 19-1-2004 at 08:28
Distilled water is considered non-conducting but it usually has some conductivity to it unless specially purified. As in not exposed to atmosphere
and such. In addition water does have the self ionization constant and even the tinyist impurities can render it conductive.
axehandle - 19-1-2004 at 08:30
Ok, I stand corrected. Would motor oil work as a replacement?
chemoleo - 19-1-2004 at 08:39
What is the distance between your electrodes? I.e. at the point where they enter the glass vessel? I don't know your setup, but it is possible
that any condensing liquid on the rubber through which the electrodes enter cause an electric short circuit.
Besides, you may know that electric lightening in rainy weather is less powerful than lightening without rain/clouds. This is because the absence of
water allows the voltage to build up, while this is not the case if water is present.
I therefore wouldnt think of water as an insulator in this case - at least, water or water vapour will be MUCH less of an insulator than dry
air/atmosphere on its own.
If I was u I would test the whole thing first, without distilled water in the vicinity and such, just the spark and the rubber plug. Does it work
then?
PS what is NST-driven?
I am a fish - 19-1-2004 at 08:39
Absolutely pure water is very slightly conducting due to spontaneous ionisation:
2H<sub>2</sub>O --> H<sub>3</sub>O<sup>+</sup> + OH<sup>-</sup>
At standard temperature and pressure, approximately 1 in 10,000,000 water molecules are ionised.
axehandle - 19-1-2004 at 08:42
>What is the distance between your
> electrodes? I.e. at the point where they
> enter the glass vessel? I don't know your >setup, but it is possible that any
approx. 100mm.
>If I was u I would test the whole thing
>first, without distilled water in the vicinity
>and such, just the spark and the rubber
>plug. Does it work then?
Yes, perfectly.
PS what is NST-driven?
"Neon Sign Transformer". Mine gives 9kV, 60mA.
chemoleo - 19-1-2004 at 08:49
Lol I didnt notice this before - you keep the electrodes in water that protrude out of your vessel? That is obviously the problem! Just cool your
vessel, but do NOT submerge the electrodes! keep them away from the water. It will work just fine then, I am sure.
As I said, distilled H2O will be a better conductor than air, so this is where you get shorted.
PS even oil might be a problem... so just dont bother submerging those electrodes! Besides, then you can cool your vessel more easily, with a NaCl/ice
bath or so.
[Edited on 19-1-2004 by chemoleo]
axehandle - 19-1-2004 at 08:53
Trouble is, the electrodes get hot, VERY hot.
The NST output is in the 500W range, so
theres a lot of heat to remove.
Anyone care to illuminate me on my motor
oil submertion idea?
axehandle - 19-1-2004 at 08:55
>"As I said, distilled H2O will be a better
>conductor than air, so this is where you get
>shorted."
Quite so. I was actually shorted last night,
left hand to right hand. Very very unpleasant!
chemoleo - 19-1-2004 at 09:03
lol I happened to experience once the same (when I was young and adventurous) - left to right hand... but then it was 20 kV (from an central heating
spark making transformer). The spark, at its greatest length, would be 6 cm long.
Anyway, it left two little black craters on both of my fingertips! (and caused me to use rubbercoated forceps/gloves thereafter)
That's a great experiment for any kewl out there 
PS how long is your spark at maximum? You can use it to cut materials such as stones, glass, etc apart! It works quite nicely!
PS 2 Just use THICK electrodes then! They wont get so hot!
[Edited on 19-1-2004 by chemoleo]
axehandle - 19-1-2004 at 09:19
The maximum spark length is somewhere around 10 centimeters if it's allowed to
"wander" from a small gap to a large gap (V-shaped electrodes).
The electrodes are already 4mm thick round steel, but I suppose I could make new ones
using 8mm, or even 10mm steel.
Can't get over the fact that I nearly electrocuted myself yesterday. I don't
know the frequency of the NST, but suspect
that it could interfere with the heart's regulatory system.
Quantum - 11-2-2004 at 21:09
Chemoleo, do you have any info on cutting things with a NST arc? Also are you a cop? Chemo LEO(law enforcement officer) or is it chemoleo like jello?
axehandle - 11-2-2004 at 23:22
Actually the perfect cooling medium would be Fluorinert, but the listed price is about $15 for 150milliliters....
The point is moot however, I'm using ceramics and air cooling now, and provided i cover the protruding electrode parts and cables with PVC hose,
I _could_ submerge the entire vessel in water.
Peltier
Turel - 12-2-2004 at 09:44
Ever considered using a power supply and controller for an electronic Peltier cooler? Fashion your electrodes to attach to a flat plate heatsink
(copper) and remove the massive heat with a computer peltier device.
This may be overkill, or perhaps not economic, but it should work great.
axehandle - 12-2-2004 at 09:52
Actually I have considered it. But with my new design it shouldn't be necessary. (I hope)