Re: Nitrogen VS Compressed air quenching

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Original poster: "Jim Lux" <jimlux-at-earthlink-dot-net> 


----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Sunday, May 02, 2004 3:42 PM
Subject: Re: Nitrogen VS Compressed air quenching


 > 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

I'll bet a 300 cu ft T sized bottle doesn't cost much more to fill.  A few
(<5) years back, I was paying around $16 for a T bottle of nitrogen.  You
don't need any exotic grade, of course.


I wonder why there's such a huge difference.  Could it be temperature
related?  If 42cu ft lasts for 16-20 minutes, that implies an airflow of
2cfm.

If nitrogen is a lot better, then rigging up a compressor (or a fan) and
some cooling tubing with a recirculating arrangement might be worthwhile.
You're running 100 psi, but I assume that's at the regulator.  What's the
pressure at the gap (or, more properly, at the orifices). Are you at choked
flow (i.e. the flow through slot/hole is supersonic)?