A $3-$m tall countercurrent spray chamber will be used to capture fly ash particles. Pilot research was

conducted to test efficiency of this device for capturing $8-\backslash$mu m particles. What is the efficiency of this device

given the following data from the experiment?

i$.0\mathrm{.}6$ L$/$min of water are added for every $1$ m$3/$min of air

ii$.$ Superficial gas velocity $=20$ cm$/$s

iii. Droplet diameters average $400\backslash$mu m $(0\mathrm{.}040$ cm$)$

iv$.$ Fractional collection efficiency of a single droplet $=0\mathrm{.}50$