# Exhaust gases from a manufacturing plant are being discharged through a 10-m tall exhaust stack with outer

## Question:

Exhaust gases from a manufacturing plant are being discharged through a 10-m tall exhaust stack with outer diameter of 1 m, wall thickness of 10 cm, and thermal conductivity of 40 W/m·K. The exhaust gases are discharged at a rate of 1.2 kg/s, while temperature drop between inlet and exit of the exhaust stack is 30°C, and the constant pressure specific heat of the exhaust gasses is 1600 J/kg · K. On a particular day, the outer surface of the exhaust stack experiences radiation with the surrounding at 27°C, and convection with the ambient air at 27°C also, with an average convection heat transfer coefficient of 8 W/m^{2 }· K. Solar radiation is incident on the exhaust stack outer surface at a rate of 150 W/m^{2}, and both the emissivity and solar absorptivity of the outer surface are 0.9. Assuming steady one-dimensional heat transfer,

(a) Obtain the variation of temperature in the exhaust stack wall and

(b) Determine the inner surface temperature of the exhaust stack.

## Step by Step Answer:

**Related Book For**

## Heat And Mass Transfer Fundamentals And Applications

**ISBN:** 9780073398181

5th Edition

**Authors:** Yunus Cengel, Afshin Ghajar