Cooling/crystallizing, for food products, comprises use of liquid nitrogen in heat exchanger with cooling fluid

摘要

The process, in which a product (1) is cooled or crystallized by thermal exchange through a wall (4) with a fluid (2) that has a balanced vapor phase, uses a cold source in the form of liquid nitrogen circulating in a heat exchanger (3) in contact with the fluid. The liquid/vapor balance of the fluid is regulated with the aid of a temperature probe (5), a flow controller (7) such as a solenoid or proportional valve, and the temperature of the liquid nitrogen as measured by a second probe (6). The surface of the wall in contact with the cooled product is cleared from time to time by a scraper.