Chill out or freeze solid with calcium chloride
15 Jan 2000
As part of a MAFF-funded LINK research project, the Bristol University-based Food Refrigeration and Process Engineering research Centre (FRPERC) has built a novel refrigeration system for supermarket display cabinets. Based on the use of calcium chloride brine as a secondary refrigerant, the experimental pilot plant can serve either chilled or frozen food retail display cabinets.
CaCl2 brine has good thermodynamic properties and, says the FRPERC, is cheap compared with glycols and oils. It is used extensively for industrial refrigeration at frozen temperatures, but its use in food production and retail industries has been limited because of the toxic corrosion inhibitors that are required in the presence of air.
Recent developments in non-toxic inhibitor technology, however, now offer the prospect of safe, corrosion-free brines based on CaCl2. The FRPERC plant now being commissioned will be used to assess the performance and corrosiveness of the brine in retail applications.
When commissioning is complete, the temperature performance of the system will be tested first on a 4m chilled upright display cabinet, and then on a 3m frozen well cabinet. The results will then be published, together with a guide to design procedures and required thermophysical data.
