Answered>Order 3610

Countercurrent stage striping is to be used to remove a taint from cream. The taint is present in the original cream to the stripping at a concentration of 20 parts per million (ppm). For every 100 kg of cream entering per unit time, 50 kg of steam will be used for stripping. It is desired to reduce the concentration of the taint in the cream to 1 ppm. The equilibrium relation between the taint in the steam vapor and the liquid cream is yA=10xA, where yAis ppm of taint in the steam and xAppm in the cream. Determine the number of theoretical stages needed. [HINT: In this case, for stripping from the liquid (L) stream to the vapor (V) stream, the operating line will be below the equilibrium line on the yA-xAdiagram. It is assumed that none of the steam condenses in the stripping. Use ppm in the material balances.]