Answer to Question #191440 in Chemical Engineering for Gokul

Question

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.

Answer 1

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.