Assignment On Evaporators.docx

EVAPORATION Removing water through drying or evaporation is an effective way of preserving many foods. Semi-solid foods are dried to low moisture content by impinging the product with hot air, placing a slurry on a heated drum, removing water by osmotic solutions, then introducing the product into a vacuum or freezing followed by drying in a vacuum. Some liquid foods are spray dried by atomizing the product into a hot air stream. Liquid foods may also be concentrated into syrups and sauces by evaporating water at the boiling point, very often at low pressures. Drying technologies are chosen to maximize product throughput, limit thermal damage, and provide reasonable costs. Evaporators are designed to limit high temperatures and long process times when necessary. In addition, several systems have been developed to maximize energy efficiency through recovery of heat from product vapour.

DIFFERENT TYPES OF EVAPORATOR:  Open pan evaporator/Jacketed pan evaporator  Calandria type evaporator/standard vertical tube evaporator /short tube evaporator  Falling film evaporator/long tube evaporator/thin film evaporator  Climbing film evaporator/long tube evaporator/thin film evaporator  Forced circulation evaporator  Agitated film evaporator/modified falling film evaporator

APPLICATIONS OF DIFFERENT EVAPORATORS IN FOOD INDUSTRY: 1)OPEN PAN EVAPORATOR/JACKETED PAN EVAPORATOR In food industry open pan evaporator is used for the preparation of khoa ,ghee etc. In canning industry used in the concentration of jam, jellies and tomato puree. Capacity : 180-200kg/hr.

2)CALENDRIA TYPE EVAPORATOR/STANDARD VERTICAL EVAPORATOR/SHORT TUBE EVAPORATOR In sugar industry, this evaporator used in the evaporation of cane sugar juice. Capacity:5500-12000 tonnes of cane/day

3)FALLING FILM EVAPORATOR/LONG TUBE EVAPORATOR/THIN FILM EVAPORATOR In milk industry used in evaporated and condensed milk. Capacity:10kg/hr to 100 tonne/hr.

4)CLIMBING FILM EVAPORATOR/LONG TUBE EVAPORATOR/THIN FILM EVAPORATOR Used in beverages industry ( fruit juices like -orange and mango) Capacity:5kg/hr to 5000kg/hr

5)FORCED CIRCULATION EVAPORATOR This evaporator is used in the concentration of caustic and brine solution and also in evaporation of corrosive solution. It is used in beverage industry which deals with citrus fruits juices. Used in concentration and crystallization of mono sodium glutamate (MSG) and citric acid. Capacity : 500 to 50000 Ltrs.

6)AGITATED FILM EVAPORATOR/MODIFIED FALLING FILM EVAPORATOR Used in extremely viscous solution Used in concentration of milk products, juices and sugar syrup Capacity : 50Kg/hr