Determine the effective height of Stack?

Question: Determine the effective height of stack, with the following given data.

1. Physical stack is 180m tall (h) with 0.95m inside diameter (D).
2. Wind velocity (u) is 2.75m/sec.
3. Air temperature (Ta) is 20°c.
4. Barometric pressure (P) is 1000 millibars.
5. Stack gas velocity (Vs) is 11.12 m/sec.
6. Stack gas temperature (Ts) is160°c.

Solution: 

 

Height of Stack (h) = 180 m

Inside Diameter of Stack (D) = 0.95 m 

Wind velocity (u) = 2.75 m/sec

Barometric pressure (P) = 1000 millibars.

Stack gas velocity (Vs) = 11.12 m/sec.

Stack gas temperature (Ts) = 160°c. =  20 + 273 = 293k 

Air temperature (Ta) = 20°c.= 160 + 273 = 433k 

Using Equation, we have:

 

 

 

Δh = 8.92 m

H = Effective height of Stack

H = h + Δh = 180 + 8.92 = 188.92 m. 

 

Effective Height of Stack  = 188.92m