Contact members for packaged articles heated with radio frequency energy
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.
1. A process for sterilizing or pasteurizing packaged articles using radio frequency (RF) energy, said process comprising:
(a) heating a plurality of first articles in an RF heating zone while transporting said first articles through said RF heating zone on a convey line having a first configuration, wherein said convey line having said first configuration comprises a continuous drive member and a plurality of article supporting members for supporting said first articles;
(b) replacing at least a portion of said plurality of first article supporting members with a plurality of second article supporting members to thereby provide a convey line having a second configuration; and
(c) heating a plurality of second articles in said RF heating zone while transporting said second articles through said RF heating zone via said convey line having said second configuration,
wherein said first and second articles have different dimensional and/or dielectric characteristics,
wherein said first and second article supporting members are differently configured to account for the different characteristics of said first and second articles,
wherein each of said first and second article supporting members comprises a rigid support structure and an article contact member coupled to said rigid support structure, wherein said article contact member comprises an energy absorptive component having a dielectric constant in the range of 20 to 150 and a dielectric loss factor in the range of 10 to 1500, wherein said rigid support structure has a dielectric loss factor of not more than 10 or a conductivity of greater than 1×10 6 Siemens per meter, and wherein the dimensions of said article contact members of said first and second article supporting members are different and/or the dielectric properties of the energy absorptive components of said first and second article supporting members are different.
2. The process of claim 1 , wherein said rigid support structure is formed of stainless steel.
3. The process of claim 1 , wherein said rigid support structure comprises an elongated arm.
4. The process of claim 1 , wherein said article contact member comprises an insulating component surrounding said energy-absorptive component, wherein said insulating component has a dielectric loss factor of not more than 10, wherein at least a portion of said insulating components are positioned between said energy absorptive component and the packages of said articles during said heating of step (c).