ME416 Air Pollution Control

Homework Problems #4

1. (5 pts) What is the Stability Class (letter) for a sunny summer afternoon about 5pm with the sun about 30 degrees above the horizon and the wind speed at 10m equal to 3 m/s? What is the range of environmental temperature gradients expected for this case?

2. (10 pts) Calculate the effective stack height for a stack 70 m tall with a diameter of 1 m and an actual gas flowrate of 10 acm/s. The stability case is C and the stack is in an urban area. The windspeed is 3 m/s at 10 m. The atmospheric pressure is 1 bar, the average air temperature is 25° C, the molecular weight of the stack offgas is 29 and the temperature of the stack offgas is 100° C. Check for downwash and if appropriate, compare the results from all three correlations.