(a) A furnace wall is made of composite wall of total thickness 550mm…
Previous year question for HEAT TRANSFER.
Question
(a) A furnace wall is made of composite wall of total thickness 550mm. The inside layer is made of refractory material ($K = 2.3 \text{ W/mK}$) and outside layer is made of an insulating material ($K = 0.2 \text{ W/m-K}$). The mean temperature of the glass inside the furnace is $900^{\circ}\text{C}$ and interface temperature is $520^{\circ}\text{C}$. The heat transfer coefficient between the gases and the inner surface is taken as $230 \text{ W/m}^2\text{C}$ and between the outside surface and atmosphere as $46 \text{ W/m}^2\text{C}$. Taking air temperature as $30^{\circ}\text{C}$, calculate (i) required thickness of each layer, (ii) the rate of heat loss per square meter area. [20]
(b) [Missing part label, or continuation of Q1 or general instruction, but printed as Q2(a)]
- Year: 2018
- Subject: HEAT TRANSFER