Tutorial 4

Question 1

4-23 A brick of 203 x 102 x 57 mm in dimension is being burned in a kiln to ll00 °C, and

then allowed to cool in a room with ambient air temperature of 30°C and convection heat

transfer coefficient of 5 W/m2-K. If the brick has properties of ρ= 1920 kg/m3 , cp = 790 J/kg-

K, and k= 0.90 W/m-K, determine the time required to cool the brick to a temperature

difference of 5 oC from the ambient air temperature.