Multi Effect Evaporator

Evaporation deals with the concentration of a non-volatile Solute from a solution by the removal of required amount of volatile solvent. Usually the solvent is water. By vaporizing a part of the solvent, useful product i.e. the concentrated solution or thick liquor is produced and the Vapour is discarded. Lung tube evaporators are usually used for the concentration of foamy liquids. The set-up is consists of two evaporators fitted in series. Each is made up of Stainless Steel tubes surrounded by a Stainless Steel jacket and fitted with accumulator. Dilute solution is feed to the first evaporator. Steam from. a steam generator is supplied to evaporator 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 vapours of volatile solvent produced in first evaporator are supplied to the second evaporator. The vapours of volatile solvent are condensed in a shell & tube type condenser and the balance non-volatile solute collected in the accumulator is recycled through the evaporator.

Experiment:

To concentrate a solution and to evaluate the following at steady state:

• Material and Heat Balance
• Economy and the capacity of the evaporator for different feeding arrangement
• Overall heat transfer co-efficient.

Utilities Required:

• Water supply 10 lit/min (approx.) and Drain
• Electricity Supply: 1 Phase, 220 V AC, 3-6 kW
• Required Chemicals