Cryogenic technology

D. R. Bennett and co-workers, Cyogenic Air Separation Equipment Design, AIChE Tutorial on Cryogenic Technology, Houston, Tex., 1993. 

Data on the thermal conductivity for a variety of foams used at cryogenic temperatures have been presented by Kropschot Cryogenic Technology, R. W. Vance, ed., Wiloy, New York, 1963, p. 239). Of aJl the foams, polyurethane and polystiyene have received the widest use at low temperatures. The major disadvantage of foams is that they tend to crack upon repeated thermal cychng and lose their insulation value. 

CASE 1 CRYOGENIC TECHNOLOGY HELPS OPTIMIZE PRODUCTIVITY ... 

Liquefied petroleum gases (LPGs), 13 684, 691-692 18 664-665 consumption of, 10 136 gas purification, l 618t as a motor fuel, 12 432 recovery by cryogenic technology, 854-56... 

Fig. 9.15 Saturation vapor pressure p of various substances retevant for cryogenic technology in a lemperalurerange ofT= 2-80 K...

Several practical applications of cryogenics technology are described elsewhere in this encyclopedia. Check Alphabetical Index. 

LNG production involves cryogenic technologies that include concepts, refrigerants and process design. A state-of-the-art review of liquefaction concepts - especially on smaller scale - have been given. Cost level and relative pricing have been indicated in order to provide rough estimates. 

National Institute of Standards and Technology, Cryogenics Technologies Group Boulder, Colorada... 

CLYDE McKINLEY has been with Air Products and Chemicals in R D roles for over 25 years. Much of this period has been in cryogenic technology, basic properties studies, and process development. His personal involvement in the liquid hydrogen program in America provides a unique perspective for his chapter. 

Vance, R., and Weinstock, H., Applications of Cryogenic Technology, Tinnon-Brown, Inc., Los Angeles, CA, 1969. 

Another factor augmectting the heat conductivuty of plastic foams under conditions is the absorbed moisture. For example, for CCljF-foamed polyurethane at 25 °C and a relative humidity of 65%, the ambient moisture diffusion rate is 10-20 g/m for 24 h. Especially strong is the effect of moisture on heat conductivity if the temperature differential across the sample is considerable. For example, in plastic foams used in cryogenic technology, the inner layers are exposed to low temperatures the water vapor first condenses and is then convected into ice. Since the thermoconductivity of water and ice are 0.5 and 1.5 kcal/m x h °C, respectively, even minor tunounts have a considerable detrimental effect of the heat insulating capacity of a foam material... 

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