Abstract: An insulating material is provided comprising an air tight enclosure maintained under vacuum and containing a plurality of alternate, successive layers of thin reflective foil and thin insulating sheeting. These layers are tightly packed together and are arranged generally perpendicular to the heat flow. The enclosure walls are thin and sufficiently ductile or resilient so that when air is pumped from inside the enclosure, the walls deform in response to atmospheric pressure and transmit this load to the layers of foil and sheeting thereby compressing them tightly together.

Abstract: A cabinet cooler or freezer which efficiently utilizes cryogenic refrigeration either with or without mechanical refrigeration. The freezer intermittently freezes relatively large batches of food by efficiently utilizing the natural expansion effect of a liquid cryogen, in combination with mechanical circulation by blowers, to create an overall circulation that efficiently removes heat from the food. A secondary circulation effect is induced, in a manner similar to the operation of a jet pump, which amplifies the circulation and allows CO.sub.2 to be employed as the cryogen with modulating valve control to achieve uniformly low temperature throughout the cabinet without snow build-up on the cabinet bottom. Some cabinet versions create a cyclonic circulation pattern about a vertical axis that is particularly effective.

Abstract: A cabinet cooler or freezer which efficiently utilizes cryogenic refrigeration either with or without mechanical refrigeration. The freezer intermittently freezes relatively large batches of food by efficiently utilizing the natural expansion effect of a liquid cryogen, in combination with mechanical circulation by blowers, to create an overall circulation that efficiently removes heat from the food. A secondary circulation effect is induced, in a manner similar to the operation of a jet pump, which amplifies the circulation and allows CO.sub.2 to be employed with modulating valve control to achieve uniformly low temperature throughout the cabinet without snow build-up on the cabinet bottom. Some cabinet versions create a cyclonic circulation pattern about a vertical axis that is particularly effective.