I pressurize my gap with a small vacuum cleaner motor, since I couldn't find
a small centrifugal blower with the oomph to do the job. Since it's a
series-wound motor, I run it at half line voltage to keep it quiet and
prolong its life. It actually gives adequate pressure at 30% line voltage.
The motor before it ran 17 years at full voltage--not bad for a used motor I
found on a Sunday in Gallup, New Mexico, while the audience waited
patiently. The spirit of the Big N. T. was watching over us that day.
The noise goes up as the square, or the cube, or some power law of the
voltage, so at 50% it's pretty quiet.
But LN2 would be cool (pun intended), especially if you got a big plume of
vapor.
---Carl
(Irrelevant point of interest for power law fanatics--the life of an
incandescent light bulb is inversely proportional to the thirteenth power of
the applied voltage.)
-----Original Message-----
From: Jim Lux
Sent: Saturday, November 08, 2014 8:07 AM
To: tesla@xxxxxxxxxx
Subject: Re: [TCML] Air compressor quenching
On 11/7/14, 5:12 PM, John Cooper wrote:
I have all the nitrogen I want at work through piping and hoses. But no
idea where you would find some and if bottled how long would it last?
A standard K sized bottle holds about 220 cubic feet of N2 (at room temp
and pressure). A T bottle holds about 300 cubic feet. A T bottle is
about $8/fill plus the rent on the bottle which is about 8-10 cents/day.
If you need more, the usual solution is to use LN2. There are low
(22psi) and high pressure (230 psi) dewars available. A 180 liter fill
is about $70, but the tank is a lot more expensive to rent. 180 liters
is about 4100 standard cubic feet. You'll lose a small amount to
evaporation each day (<1%)
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