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US 12,035,734 B2Granted
High intensity radio frequency heating of packaged articles
OwnerHarold Dail Kimrey, Jr.inventor
Life of this patent
Estimating the term…
Abstract
Heating systems utilizing radio frequency (RF) energy and methods for using the same to rapidly and uniformly heat packaged articles moving through the system on one or more convey lines. These systems may be useful for a variety of processes, including the pasteurization or sterilization of packaged foodstuffs.
Claims20
A process for sterilizing or pasteurizing articles using radio frequency (RF) energy, said process comprising:
- (a) passing a plurality of articles through a liquid contact zone of an RF heating system, wherein said articles are in contact with liquid during at least a portion of said passing, wherein said liquid contact zone comprises an initial thermal regulation zone, an RF heating zone, and a subsequent thermal regulation zone;
- (b) regulating the temperature of said articles passing through said initial thermal regulation zone to promote temperature uniformity of the articles;
- (c) subsequent to said regulating, heating said articles passing through said RF heating zone with RF energy to thereby increase the temperature at the geometric center of at least a portion of said articles by at least 20° C. between the inlet and outlet of said RF heating zone;
- (d) subsequent to said heating, regulating the temperature of said articles passing through said subsequent thermal regulation zone to thereby decrease the temperature at the geometric center of at least a portion of said articles by at least 10° C.,
- wherein at least one of the following statements (i) through (iii) is true:
- (i) the residence time of said articles passing through said RF heating zone is at least 1 percent and not more than 30 percent of the residence time of said articles passing through said initial thermal regulation zone;
- (ii) the residence time of said articles passing through said RF heating zone is at least 0.5 and not more than 20 percent of the residence time of said articles passing through said subsequent thermal regulation zone;
- and
- (iii) the residence time of said articles passing through said RF heating zone is not more than 10 percent of the total residence time of said articles passing through said liquid contact zone, and
- wherein each of said articles is a foodstuff contained in a sealed package, wherein said foodstuff has a dielectric constant in the range of 20 to 150 and a dielectric loss factor in the range of 10 to 1500, and wherein said foodstuff in each of said sealed packages has a volume of at least 4 cubic inches.
7 more elements
A process for sterilizing or pasteurizing articles using radio frequency (RF) energy, said process comprising:
- (a) passing a plurality of articles along a first travel path extending from an inlet to an outlet of an initial thermal regulation zone and, during at least a portion of said passing, regulating the temperature of said articles to promote temperature uniformity;
- (b) heating said articles in an RF heating zone with RF energy to thereby increase the temperature at the geometric center of at least a portion of said articles by at least 20° C.;
- and
- (c) passing said articles along a second travel path extending from an inlet to an outlet of a subsequent thermal regulation zone and, during at least a portion of said passing, regulating the temperature of said articles to thereby decrease the temperature at the geometric center of at least a portion of said articles by at least 10° C.,
- wherein at least one of said first and said second travel paths is a non-linear travel path and has a distance at least 2 times greater than the linear distance between the respective inlet and said outlet of said initial and/or subsequent thermal regulation zone.
2 more elements
A process for sterilizing or pasteurizing articles using radio frequency (RF) energy, said process comprising:
- (a) discharging RF energy into an RF heating zone;
- (b) passing a plurality of said articles through said RF heating zone on at least one convey line;
- and
- (c) heating said articles on said convey line in said RF heating zone with at least a portion of the RF energy discharged into said RF heating zone, wherein said heating is sufficient to increase the average temperature at the geometric center of said articles by at least 20° C. to a temperature of at least 65° C.,
- wherein during said heating of step (c) the average lengthwise power intensity in said RF heating zone is at least 3 KW per foot and wherein each of said articles is a foodstuff contained in a sealed package, wherein said foodstuff has a dielectric constant in the range of 20 to 150 and a dielectric loss factor in the range of 10 to 1500, wherein said foodstuff in each of said sealed packages has a volume of at least 4 cubic inches.
2 more elements
Dependencies are inferred from the claim text.