Steel balls (diamęter = 21 mm, p= 7833 kg/m , k = 54 W/m-°C, Cp = 0.465 kJ/kg-°C, and a = 1.474x10 m /s) are annealed by heating them first to 870°C in a furnace and then allowing them to cool slowly to 85°C in ambient air at 27°C. The average heat transfer coefficient is 69.9 W/m¯.°C. How long the annealing process will take (in Seconds)?

Steel balls (diamęter = 21 mm, p= 7833 kg/m , k = 54 W/m-°C, Cp = 0.465 kJ/kg-°C, and a = 1.474x10 m /s) are annealed by heating them first to 870°C in a furnace and then allowing them to cool slowly to 85°C in ambient air at 27°C. The average heat transfer coefficient is 69.9 W/m¯.°C. How long the annealing process will take (in Seconds)?

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter7: Forced Convection Inside Tubes And Ducts

Section: Chapter Questions

Problem 7.4P

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