초록 ▼

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 flui

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.

대표청구항 ▼

A food freezer comprising: an enclosure; conveyor means for supporting food products within said enclosure and carrying said food products therethrough; mechanical refrigeration means for freezing said food products as they are carried through said enclosure, said mechanical refrigeration means comp

A food freezer comprising: an enclosure; conveyor means for supporting food products within said enclosure and carrying said food products therethrough; mechanical refrigeration means for freezing said food products as they are carried through said enclosure, said mechanical refrigeration means comprising: a first heat transfer fluid; a first closed refrigeration circuit containing said heat transfer fluid, comprising a first evaporator disposed within said enclosure, a first condenser disposed outside of said enclosure, means to effect flow of said first heat transfer fluid through said first evaporator and said first condenser, and a compressor to compress fluid entering said first condenser; means to effect heat transfer from said food products to said first heat transfer fluid in said first evaporator so as to evaporate fluid therein without direct contact between said food products and said first heat transfer fluid, comprising a gas within said enclosure and blower/fan means for effecting gas flow over said first evaporator and said food products within said enclosure; a second closed refrigeration circuit comprising a second heat transfer fluid, a second evaporator disposed in thermal communications with said first condenser, a second condenser, and means to convey a second heat transfer fluid through said second refrigeration circuit so as to effect transfer of heat from said first heat transfer fluid to said second heat transfer fluid; and means tor emove heat from said second condenser; wherein said first heat transfer fluid consists essentially of CO2 and is maintained at pressures of between 60.4 psig and 120 psig while in said first evaporator.