Steel balls 10 mm in diameter are annealed by heating to 1,150 K and then slowly cooling to 450 K in an air environment for which T∞ = 325 K + at, where a = 0.1875 K/s and h = 25 W/m2 · K. Assuming the properties of the steel to be k = 40 W/m · K, ρ = 7,800 kg/m3, and c = 600 J/kg · K, estimate the time required for the cooling process.

Steel balls 10 mm in diameter are annealed by heating to 1,150 K and then slowly cooling to 450 K in an air environment for which T∞ = 325 K + at, where a = 0.1875 K/s and h = 25 W/m2 · K. Assuming the properties of the steel to be k = 40 W/m · K, ρ = 7,800 kg/m3, and c = 600 J/kg · K, estimate the time required for the cooling process.

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.

Chapter5: Analysis Of Convection Heat Transfer

Section: Chapter Questions

Problem 5.36P

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