The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 27, 1991
Filed:
May. 08, 1990
Roger F Gyger, Naperville, IL (US);
Gary D Lang, Wooster, OH (US);
Kenneth L Burgers, Oak Park, IL (US);
Liquid Carbonic Corporation, Chicago, IL (US);
Abstract
A food freezer having a mechanical refrigeration system comprising first and second closed-loop fluid circuits, wherein the first fluid circuit employs carbon dioxide as its refrigerant and transfers heat to the second fluid circuit, which in turn transfers heat to the environment or to another fluid circuit. In the first fluid circuit evaporator, carbon dioxide is maintained at pressures between 60.4 psig and 120 psig. In a preferred embodiment of the invention, the freezer employs at least two separate blowers or fans for circulation of air or other gas in the freezer enclosure. One blower/fan operates continuously to maintain circulation of cold air or gas in the freezer. The other blower/fan operates intermittently or at variable speeds to vary air flow across the evaporator, and thereby increase or decrease heat transfer from the freezer interior to the first fluid circuit evaporator to maintain the freezer interior at a desired temperature or within a desired temperature range.