Anti-Clogging, Flow-Regulating, Joule-Thomson Cryostat General Pneumatics Corporation (GPC), Phoenix, Arizona

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Anti-Clogging, Flow-Regulating, Joule-Thomson
CryostatGeneral Pneumatics Corporation (GPC),
Phoenix, Arizona
Innovation GPC developed a patented new type of
Joule-Thomson (J-T) cryostat featuring exclusive
anti-clogging, flow regulation capabilities to
satisfy a need to provide very low temperature
cooling for infrared sensors, super conductors,
supercooled electronics, spacecraft, nuclear
contamination detectors, and cryosurgery.

• Accomplishments
• As a result of a NASA SBIR contract, GPC
  developed a J-T cryostat that can operate
  continuously with gas contamination levels that
  would quickly clog conventional cryostats. GPC
  cryostats employ a more rugged and stable means
  of flow regulation than the conventional ones,
  and can be equipped with a manual or actuator
  driven flow adjustment which is especially
  useful in developmental and laboratory
  applications. The patented anti-clogging,
  flow-regulating features have been incorporated
  in cryostats ranging in cooling capacity from ¼
  watt to 50 watts.
• GPC has manufactured J-T Cryostats in small
  production runs for custom design applications.
• GPCs Western Research Center (GP WRC) was
  specifically established to research and develop
  cryorefrigerators, Stirling engines and
  refrigerators, and new approaches for thermal
  management and energy conversion.
• GPC, founded in 1959, has established
  world-wide recognition for the custom design and
  manufacture of high reliability pneumatic and
  hydraulic valves, pressure regulators,
  aspirators, and accumulators for aerospace
  applications.

Anti-clogging, Joule-Thomson Cryostat
Government/Science Applications The specific
objective of the NASA KSC Phase I SBIR project
was for GPC to design, build, and test a
prototype self-regulating Joule-Thomson cryostat
incorporating an anti-clogging nozzle with flow
regulation by differential thermal expansion
coefficients and a manual adjustment means.
GPCs cryostat, initially sized to meet ¼ watt
common module requirements, demonstrated
continuous operation in simultaneous testing
using commercial grade nitrogen with
contamination levels which repeatedly clogged
conventional cryostats within 6 minutes. In
Phase II, the cryostat design was extended to 50
watts cooling capacity at 77 K. The cryostat
was incorporated into a prototype closed-loop
cryocooler featuring a new oil-free sealed
high- pressure compressor and novel closed-loop
control scheme, which was delivered to KSC in
September 1988. Later, GP WRC worked with
EGG ORTEC in Oak Ridge, Tennessee to apply the
technology to cooling high-resolution gamma-ray
spectrometers, under a contract to Bechtel
Nevada. The U.S. Department of Energys Remote
Sensing Laboratory in Nevada directed the
development. The cryostat development is a key
part in the development of more portable
high-purity germanium gamma-ray detectors.
These are necessary to discern among
radionuclides in medical, fuel, weapon, and
waste materials. The ability to monitor nuclear
materials, verify possible hazards, and develop
counterproliferation tactics has become
increasingly crucial to global security.
Commercialization GPC has designed and produced
custom J-T cryostats for NASA-JPL, Sandia-LNL,
BEI Systron Donner, Aerojet ESD, EGG, Bechtel
Nevada, and CryoGen. Prospective applications
have included spacecraft, computer electronics,
nuclear contamination detection and
counter-proliferation, and cryosurgery. One
development was a highly sophisticated,
adjustable, two-stage xenon/krypton cryostat
assembly for Aerojet ESD. GPC also designed an
anti-clogging cryostat to continuously produce
solid hydrogen at 10 K. Another cryostat was
successfully tested at NASA-JPL in an
experimental 80 K sensor cooler, which achieved a
temperature stability 3 orders of magnitude
better than conventional cryostats. A recent
development for the U.S. Dept. of Energy Remote
Sensing Laboratory, operated by Bechtel Nevada,
is a common module-size (0.204-inch bore,
2.62-inch deep coldwell) self-regulating cryostat
which produces up to 16 watts of refrigeration
for several hours using 3000 psi argon to cool a
HPGe gamma ray detector to below 100 K. For
CryoGen, GPC provided a prototype anti-clogging
cryostat for a closed-cycle cryosurgery
system. Cumulative sales revenues to date by
target market sector are approximately 1
million. The remaining technological or business
development necessary for large volume
commercialization and joint ventures depends on
securement of the patent currently in process to
allow marketing promotion. There have been two
patents granted, and another one is in process.
Points of Contact - NASA (Frank Howard,
407-867-4181) - GPC (Woody Ellison,
602-278-5678) SBIR Phase II NAS10-11322
NASA Field Center Kennedy Space Center Date of
Update Sept. 15, 1998 Success Story 10-005