Chapter 10 Boiling and Condensation10-82 Saturated steam condenses on a suspended silver sphere which is initially at 30°C. The time needed for the temperature of the sphere to rise to 50°C and the amount of steam condenses are to be determined. Assumptions1The temperature of the sphere changes uniformly and thus the lumped system analysis is applicable.2The average condensation heat transfer coefficient evaluated for the average temperature can be used for the entire process. 3Constant properties at room temperature can be used for the silver ball. PropertiesThe properties of water at the saturation temperature of 100°C are hfg= 2257×103J/kg and ρv= 0.60 kg/m3. The properties of the silver ball at room temperature and the properties of liquid water at the average film temperature of TTTfsave=+=(),sat2/⋅(100 + 40)/2 = 70°C are (Tables A-3 and A-9), Silver Ball:ρα==×=⋅°°−10 500174 1023542936, kg/mm/sC J/kgCW/m C2plkLiquid Water:μllpllk=°°−977 50 404 1041900 66333.
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This note was uploaded on 01/24/2012 for the course PHY 4803 taught by Professor Dr.danielarenas during the Fall '10 term at UNF.