Measurement of Heat Conduction Through Stacked Screens
T Kuriyama, F Kuriyama, Michael A. Lewis, Ray Radebaugh
This paper describes the experimental apparatus for the measurement of heat conduction through stacked screens as well as some experimental results taken with the apparatus. Screens are stacked in a fiberglass-epoxy cylinder, which is 24.4 mm in diameter and 55 mm in length. The cold end of the stacked screens is cooled by a Gifford-McMahon (GM) cryocooler at cryogenic temperature and the hot end is kept at room temperature. Heat conduction through the screens is determined from the temperature gradient in a calibrated hear flow sensor mounted between the cold end of the stacked screens and the GM cryocooler. The samples used for these experiments consisted of 400-mesh stainless steel and phosphor bronze screen was 25.4 υm and the 325-mesh stainless steel screen wire diameter was 22.9 υm and 27.9 υm. Standard porosity values were used for the experimental data with additonal porosity values used on selected experiments. The experimental results showed that the helium gas between each screen enhanced the heat conduction through the stacked screens by several orders of magnitude compared to that in vacuum. The conduction degradation factor is the ratio of actual heat conduction and heat conduction where the regenerator material is assumed to be a solid rod of the same cross-sectional area as the metal fraction of the screen. This factor was about 0.1 for the stainless steel and 0.022 for the phosphor bronze and almost constant for the temperature range of 40 K to 80 K at the cold end.
International Cryocooler Conference | 9th | | Plenum Press
, Kuriyama, F.
, Lewis, M.
and Radebaugh, R.
Measurement of Heat Conduction Through Stacked Screens, International Cryocooler Conference | 9th | | Plenum Press, Undefined
(Accessed December 11, 2023)