Question

Particulate matter is emitted from a stack of 50 m. The atmospheric wind is 10 miles/hr. If the stack emits only PM o 120 μm in diameter with a density of 5 g/cm, what would be the downwind distance (in meter) these particles are likely to settle on the ground?

Answer 1

calculate the downwind distance as below:

v_s x / w h = 1

where, v_s is the rate of fall of the particle in m/sec

x is the downwind distance

w is the the air speed in m/s

h is the stack height in m

by using the diameter of the particle the rate of fall of particle is 0.334 m/sec, 4.4704 m/sec for w and 50 m for h

0.334 X x/ 4.4704 X 50 = 1

x = 669.2 m