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Lee Jong Suk;Hong Jeong Ho
- Korean Journal of Air-Conditioning and Refrigeration Engineering
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- v.16 no.12
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- pp.1101-1106
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- 2004
Magnetic refrigeration is based on the magnetocaloric effect (MCE)-the ability of some materials to heat up when magnetized and cool down when demagnetized. A rotary magnetic refrigeration device using gadolinium (Gd) ribbon and permanent magnets was constructed for experimental study. Gd ribbon attached around a rotating wheel is cyclically magnetized and demagnetized by permanent magnets and exchanges heat with liquid in the surrounding container. Temperature of the liquid in each divided section of the container was measured and the experimental results obtained in this study were discussed.
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Lee, Chun Sik
- The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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- v.17 no.4
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- pp.466-472
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- 1988
Pneumatic transportation systems are operated most economically, if the transportation velocity is somewhat greater than the limit velocity. Therefore it is very important to find out this limit velocity. That is well known for coarse and fine particles, but not yet for long ribbon type material. In this study a formula for the mass ratio of transported material to air in limit load point is derived for ribbon type material from the pneumatic transportation theory and the model theory. A relationship for estimating the limit velocity is also found out through experiments. The possibility of the generalization of this formula, which is obtained from a given pneumatic transportation system, should be estimated through further systematic studies.
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