Re: Nitrogen VS Compressed air quenching

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "john cooper" <tesla-at-tesla-coil-dot-com> 

Why does nitrogen work better to quench?  Consider this:  The dielectric 
strength of nitrogen is 1.00, the dielectric strength of argon is 0.18, I 
use argon in the arcylic box used with my bi-polar coil because it promotes 
streamer length, I use nitrogen because it inhibits this.  There are gasses 
with a higher dielectric strength but many of those are poisonous - 
chlorine (1.55), many are extremely expensive (300.00 for 5 lbs) - sulfur 
hexafluoride(8.50), and others are possibly explosive - many methane 
compounds.  Carbon Dioxide has three line item listings: 0.82, 0.84 & 
0.88.  This is according to the 83rd Edition of the Handbook of Chemistry & 
Physics.  Interestingly, air has 4 separate line item listings with ratings 
of 0.4-0.7, 0.97, 1.4 & 3.0.  Based on my observations and experiments, I 
would think the operable number in this application would have be the 
0.4-0.7 listing.  Nitrogen just happens to be a commonly available and 
comparatively cheap gas.

Why not build a N capture and re-cycling system?  Simple, I'd rather deal 
with a small bottle with a 15 foot non-conductive hose running into the 
coil that costs 14.00 to fill than lug around a 500lb monstrosity that 
requires its own power supply(s) costs 5000.00+ to build and takes 2 years 
to develop and construct.  There's also the headache of where to place a 
large metal mass that's possibly in very close proximity to your coil.  But 
don't let me discourage you, something useful and totally unexpected could 
come from that exercise but my guess is that this system has already been 
developed for other applications.

Also, using an old water heater for a reactive chemical container would 
definitely be ill-advised, dangerous and possibly fatal to all in proximity.

John


---------- Original Message ----------------------------------
From: "Tesla list" <tesla-at-pupman-dot-com>
Date:  Mon, 03 May 2004 08:20:17 -0600

 >Original poster: "Arpit Thomas" <arpit-at-inzo-dot-org>
 >
 >wow, thats interesting. Now what could it be about nitrogen that provides
 >better quenching? could it be the fact tehre is less oxygen to react with
 >or something? IT seems to me that if nitrogen is much better than
 >compressed air, you could save a bit of time carting a heavy tank back and
 >forth if you made a circulating system for the nitrogen. a vacuum cleaner
 >blower would be connected to the spark gap, and the exhauset of the spark
 >gap ( this is all happening in a moderately large chamber)  then goes
 >through some metal pipe which cools it, and then goes into the a resevoir,
 >such as an old water heater, then goes back to the blower. YOud fill the
 >heater up with low pressure (2 atmospheres or so? ) nitrogen, and then let
 >it last for ages :)
 >
 >How's carbon dioxide for quenching? I pinched an old (bit rusty) water
 >heater made in 1988 off another house in my street which was going to be
 >demolished, and carried it home. I'm using it as an air tank, and might use
 >it to power an air blast gap. Another potential use would be to put some
 >chemicals in which would react and generate carbon dioxxide at a pressure
 >of about 6 or 7 atmospheres. I'd then use that to blast the gap :)
 >
 >*********** REPLY SEPARATOR  ***********
 >
 >On 2/05/2004 at 4:42 PM Tesla list wrote:
 >
 > >Original poster: "john cooper" <tesla-at-tesla-coil-dot-com>
 > >
 > >I've added photos of my prototype nitrogen manifold to my website, here's
 > >the link:
 > >
 > >http://www.tesla-coil-dot-com/bipolar.htm
 > >
 > >They're at the bottom of that page.  There's a photo of it installed in
 > >the
 > >original cabinet and two close-ups of the manifold that I just took
 > >today.  For quenching ability the nitrogen is extremely effective while
 > >compressed air is barely noticeable, apples and oranges.  FWIW a 42 cubic
 > >foot bottle costs about 14.00 to fill and lasts for two 8 to 10 minute
 > >runs, the bottle and regulator were around 400.00
 >
 >
 >