Question

explain the evaporation process based on the working principle, type of equipment used and operating condition in downstream process

Answer 1

Evaporation

• This is oldest method of concentration.
• “The removal of liquid from a solution by boiling the solution in a suitable vessel and withdrawing the vapour, leaving a concentrated liquid residue."
• The rate of vaporization depends on the diffusion of vapour through the boundary layers above the liquid.

Steps in downstream processing

Evaporators:

• The equipment used to remove water from the food product is called evaporators
• Evaporators are used to separate materials based on difference in their boiling points A
• n evaporator is used to evaporate a volatile solvent, usually water, from a solution.
• Its purpose is to concentrate non-volatile solutes such as organic compounds, inorganic salts, acids or bases.
• Typical solutes include phosphoric acid, caustic soda, sodium chloride, sodium sulphate, gelatine, syrups and urea.

BASIC PARTS OF EVAPORATORS Heat exchanger , Vacuum, Vapor separator ,Condenser

Types of Evaporator: Evaporators are divided mainly into three groups. Types: 1. Natural circulation evaporator i) Evaporating pans ii) Evaporating stills iii) Short tube evaporator. 2) Forced circulation evaporator. 3) Film evaporator Types: i) Wiped Film evaporator ii)Long Tube Evaporator a) Climbing film evaporator b) Falling film evaporator