The present set-up is designed to study the operation of Calandria evaporator. It consists of a short tube vertical evaporator in which tubes are surrounded by a Stainless-Steel jacket and fitted with accumulator. Dilute solution is fed to the evaporator and heated by Steam from a steam generator to concentrate the dilute feed solution to a desired level. The jacket is fitted with a steam trap and the condensate is collected at the end of trap. The vapors of volatile solvent are condensed in a shell & tube type condenser and the balance non-volatile solute collected in the accumulator recycled back to the evaporator.