[TheForge] dry liquid nitrogen vs air compressor & liquid oxygen vs oxygen cylinders

[theforge@mailman.qth.net]

Bob Evarts wrote:

>
>Believe it or not, the government still maintains a huge helium reserve
>for use in blimps.
>Every time somebody tries to get rid of it, some buricrat saves it for
>political reasons.  I think 
>there are some high paying cushy jobs associated with it, and it employs
>the majority of 
>people from the area where it is.  
>
The facility is in Amarillo as stated in my last note.    Actually, the 
bueracrats are the ones trying to kill the program.  It is the 
scientists trying to preserve it evidently. The real story is always 
more interesting, but seldom makes a good soundbite for network news.   
Which are they going to run with " Government spends millions 
maintaining strategic reseserves of   critical and finite resource"  or 
"Government wastes millions stockpiling WW I Blimp Supplies"   An 
excerpt from the "American Physical Society's Statement on Conservation 
of Helium"  

"Helium is absolutely essential to achieving the extremely cold 
temperatures required by many current and emerging technologies. Helium 
has the lowest boiling point of any substance, including hydrogen. 
 Since modern technologies often require extremely low temperatures, 
cryogenic applications of helium have risen steadily in recent years and 
currently amount to 25% of total usage.

Helium is the only cryogenic fluid that can be used to reach the low 
temperatures required for today's superconducting electromagnets. 
Helium-cooled superconducting magnets are employed in  MRI (magnetic 
resonance imaging). Superconducting magnets also are a standard feature 
of the high-energy accelerators physicists use for research on 
fundamental particles.

Liquid helium is an essential cryogenic fluid in almost every field of 
modern laboratory research, and thus to the technologies of the future.  
Helium is also used to cool infrared and other detectors (in modern 
telescopes for example) to very low temperatures to reduce background 
noise, permitting detection of far weaker signals. Cryogenic pumping at 
liquid helium temperatures produces the extremely high vacuums often 
required in research.

Apart from its cryogenic applications, there are also more conventional 
uses for helium. The second lightest gas (after hydrogen), it is also 
chemically inert, which makes it a safe "lifting gas," as compared to 
hydrogen, but less than 10% of current helium consumption is for 
lifting. Helium is also used to create an inert environment to prevent 
oxidation or corrosion in welding, which accounts for about 25% of total 
helium consumption. Other uses include inert atmospheres for advanced 
fabrication techniques, such as semiconductor crystal growth and 
fiber-optic production (about 12%), purging large tanks, such as NASA 
fuel tanks (23%), leak detection in sealed systems (2%), and medical 
applications (another 2%).


Everything you want to know about helium can be reached from 
http://www.geocities.com/CapeCanaveral/2216/   run by a former 
Government Helium employee.  On a side note, I recall that the 
government also keeps strategic reserves of Mica, for its obsolete uses 
in electronics.    Probably a lot of good reasons for that as well.