Project Title:
Temperature Sensitive Variable Area Joule-Thomson Expansion Nozzles
11.03-1856A
Temperature Sensitive Variable Area Joule-Thomson Expansion Nozzles
General Pneumatics Corp.
7662 E Gray Road, Suite 107
Scottsdale
AZ
85260
Walker
Graham
NAS10-11322
Amount:
KSC
NAS10-11144
Abstract:
Gas liquefiers utilize isenthalpic (Joule-Thomson) expansion of cooled,compressed gas to generate refrigeration. Effective usage of the compressed gas
requires a variable mass flow rate: a high initial flow with progressive reduction
to the operating condition and intermittent flow thereafter according to load demand.
A common problem of fixed orifice nozzles is blockage by condensed contaminants
in the expanding fluid. Innovative Joule-Thomson expansion nozzles were investigated
experimentally. Materials having different coefficients of thermal contraction were
incorporated in a J-T nozzle--to achieve the load demand flow characteristic. The
problem of orifice blockage by condensed contaminants was resolved by design for
expansion of the compressed gas in a tappered annulus with the annular labyrinth
flow spoilers acting as catchment reserviors. The experimental prototype nozzles
were equipped with a screw flow adjustment capable of precise control over a wide
range, permitting the same
nozzle to be used in a variety of applications or in permitting the same application
for a wide variety of flow regimes.
Further work will extend the flow capacity of the new nozzle design to embrace most
of the potential space and non-space orientated J-T cryocoolers reliquefiers. A
critical design review will be carried out to achieve minimum production time and
cost for the new nozzles. Fabrication and test of prototype closed cycle Linde-Hampson
cryocooler liquefiers is proposed. These would incorporate the novel J-T nozzles
and an innovative diaphragm compressor with linear electric actuator.