Refrigeration & Equipment Engineering

Unit 6 - Ice Plant

6.4.2.Tube ice
Tube ice is formed on the inner surface of vertical tubes and is produced in the form of small hollow cylinder of about 50x50 mm with a wall thickness of 10 to 12mm. The tube ice plant arrangement is similar to a shell and tube condenser with the water on the inside of the tubes and the refrigerant filling the space between the tubes. The machine is operated automatically as a time cycle and the tubes of ice are released by a hot gas defrost process. As the ice drops from the tubes a cutter chops the ice into suitable lengths, nominally 50mm but this is adjustable.Transport of the ice to the storage area is usually automatic.Thus as in the flake ice plant the harvesting and storage operation require no manual effort or operator attendance.
Tube ice is usually stored to the form it is harvested, but the particular size is rather large and unsuitable for use with fish. The discharge system from the plant- therefore incorporates an ice crusher which can be adjusted to give as ice particle size to suit customer requirements. The usual operating temperature of this type of plant is -8^oc to -1^oc. The ice will be subcooled as entering the store but it is usually possible to maintain the store at -5^oc ,since particle size and shape allow the ice to be readily broken up for discharge especially with a rake system.