Air cycle combined heating and cooling for the food industry

Abstract

In the food industry there is often a need to both cook and cool food. Heating and cooling processes are rarely directly linked due to heat from refrigeration processes being insufficient to cook food. Therefore cooling and cooking is usually provided by separate pieces of equipment. This paper presents an air cycle system where the hot air was used for heating and the cold air used for fast freezing. The apparatus used a bootstrap unit developed for aircraft air conditioning which was unable to run at the low temperature required for food freezing, so a parallel compressor was added to enable the system to operate at the low temperature required for food freezing. This approach allowed temperatures as low as −140 °C and as high as 234 °C. The system cooked and froze beef burgers, and at the same time heated water up to 98 °C.