Question

A 12-by-12 inches ingot iron casting 60-in high is stripped from its mold while its temperature is 1740 °F. If it stands on end on the floor of a large foundry having wall, floor, and roof temperatures of 80°F, what is the rate of radiant-heat exchange between the casting and the roof wall, and floor surfaces?

Answer 1

Rate of radiant heat is given by

$\frac{Q}{t}=\sigma\epsilon AT^4$

Where $\sigma$ =5.67*10^-8J/sm²K⁴

A=12*12=144

$\epsilon=1$

$\frac{Q}{t}=\sigma\epsilon AT^4$

$=5.67*10^{-8}*1*144*80^4$

=334.43kJ/s