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Unformatted text preview: C HEMICAL E NGINEERING 120B Homework 2 due Wednesday, January 26, 2010 1. Read section 2 of the 120B notes. 2. A schedule 40, 2 inch steel pipe (Inner diameter 2.067 inches, wall thickness 0.154 inches) carrying steam is lagged (insulated) with 2 inches of 85% magnesia covered with 2 inches of cork. Compute the heat loss per hour per foot if the inner surface of the pipe is 250F and the outer surface of the cork is 90 F. Steel has a thermal conductivity of 26.1 BTU/(hr ft F), magnesia 0.04 BTU/(hr ft F) and cork 0.03 BTU/(hr ft F). Neglect conduction. In doing the necessary conversions between inches and feet, ponder why metric units make so much more sense. 3. Nuclear fuel pellets consist of a spherical core of radius R 1 of fissionable material of thermal conductivity k n that generates an energy per volume S . To more easily handle this radioactive material, each pellet is encased in aluminum of thermal conductivity k a and outer radius R 2 . No heat is generated within the aluminum. The entire....
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- Fall '10
- Chemical Engineering