Simultaneous Heat and Mass Transfer

Chemical Engineering Department

Introduction to Drying ProcessPresented by:

Umer Farooq

BEC-FA11-093Dated:

05-06-2014

Separation Techniques

Separation Techniques

Drying

Distillation Evaporation

Liquid-Liquid

Extraction

Drying

The Final Process in the manufacturing

process is refers to as “ the final

removal of water” is known as Drying.

In Drying

The operation involves

Evaporation Filteration Crystallization

Why Drying is important…???

To reduce cost of transportation.

To make material more suitable for

handling.

To provide definite properties i-e free

flowing nature.

To remove moisture which may lead to

corrosion.

General Principle of Drying

If the material is exposed to air at

given temperature and humidity the

material will either lose or gain water

until an equilibrium condition is

established.

Forms of moisture

Bound moisture

• This is Water content retained in such a way that it exert a vapour pressure than that if free water at same

Free Moisture

• This is water which is in excess amount of equilibrium moisture content.

Rate of Drying

It is necessary to remove free

moisture from the surface and also

moisture from the interior of the

material.

General Methods of Drying

Natural Air drying

Supercritical drying

(superheated steam drying)

Freeze drying

Industrial application

The drying process used in many

process industries i-e

In sugar industry, Pharmaceutical

industry, food industry, Paper industry,

and in caustic soda industry etc.

Questions are welcome

Thank You