Degradation of Multilayer Insulation Systems by Penetrations
The attainment of optimum performance of multilayer insulation systems in large scale cryogenic tankage applications have been less than successful. Effective thermal conductivity values as low as 2 × 10-5 Btu/hr-ft°R have been reported [1,2] for small scale cryostat testing of one-dimensional heat flow through the multilayer insulation. However, these insulations, when applied to large scale tanks, have shown thermal performances 20 to 50% poorer than those expected from cryostat measurements on identical insulation wraps, This discrepancy has usually been assigned to the interaction of penetrating members, such as fill and vent tabulation with the multilayer insulation.
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- 1.D. I. Wang, “Multiple Layer Insulations,” in: Aerodynamically Heated Structures, P. E. Glaser, ed., Prentice-Hall, Inc., Englewood Cliffs, N.J. (1962),Google Scholar
- 2.R. M. Coston and C. A. Zierman, “Cryogenic Thermal Conductivity Measurements of Insulating Materials,” presented at ASTM symposium on Thermal Conductivity Measurements of Insulating Materials at Cryogenic Temperature, Philadelphia, Pa. (Feb. 1966).Google Scholar
- 3.“Performance of Multilayer Insulation Systems for Temperatures to 700°K,” Contract NAS 2–2441, Final Report, LMSC Research Laboratory (May 1967).Google Scholar