A wet organic pigment containing 36% by weight of CCl4 is to be dried to 6% by weight (wet
basis). The drier is to operate adiabatically with fresh plus recycle air entering the dryer with
0.45 kg of CCl4 per kg of dry air. The air leaves the dryer with 0.895 kg of CCl4/kg of dry air. The
capacity of the dryer is 250 kg of bone dry solid per hour. Calculate the ratio of the recycled air
to fresh air.
wt of wet organic pigment = 35 kg/100 kg of CCL4
wt of CCL4 = 100 kg
wt of pigment = 5 kg /100 kg of CCL4
Drier is to operate adiabatically with fresh air + recycle air entering the drier = 0.43 kg of CCL4 / kg of dry air
The air leaves the drier.