Subject:- Refrigeration and Air Conditioning

Topic:- Duct Design, Controls & Applications

Difficulty:- Medium

Ice manufacturing is one of the principal needs of refrigeration and the conventional compression refrigeration system with indirect cooling is used for this purpose.

The important parts of ice plants are

i. A conventional refrigeration system using ammonia as refrigerant

ii. A cooling system

iii. A freezing tank

iv. Ice cans and lifting arrangement

v. Ice storages.

The brine is cooled first in the evaporator and then is circulated around ice cans which contain water. Heat is extracted from water by the brine and thus water in cans is converted to ice.

The brine is circulated by a pump which automatically stops when ice formation is complete, and then the cans are lifted and ice is taken out and sized as required.

Preliminary treatment, filtration and agitation of raw water is important in ice manufacturing.

The white or milky appearance of ice is due to dissolved air, gases and other impurities in water which form tiny bubbles as the water freezes. Hence to make clear ice, these bubbles are swept away by introducing stream of compressed air into the bottom of the can