Radio frequency heating system

{
  "publication_number": "US2016119984A1",
  "country": "US",
  "kind": "A1",
  "title": "Radio frequency heating system",
  "abstract": "A radio frequency (RF) heating system and process for rapidly and uniformly heating a plurality of articles on a convey line.",
  "claims": [
    "1. A radio frequency (RF) heating system for heating a plurality of articles, said RF heating system comprising: an RF generator for generating RF energy; an RF waveguide configured to be substantially filled with a liquid and, when filled with said liquid, capable of transmitting RF energy produced by said RF generator; an RF heating chamber configured to be substantially filled with said liquid and, when filled with said liquid, capable of receiving RF energy transmitted through said RF waveguide; and a convey system received in said RF heating chamber and configured to convey said articles through said RF heating chamber while said articles are being heated by RF energy. 2. The RF heating system of claim 1, further comprising at least one coaxial conduit for transmitting RF energy generated by said RF generator. 3. The RF heating system of claim 2, further comprising a coax-to-waveguide transition received in said RF waveguide and coupled to said coaxial conduit, wherein said coax-to-wave guide transition is configured to receive RF energy from said coaxial conduit and transmit RF energy into said waveguide. 4. The RF heating system of claim 1, further comprising an RF launcher for receiving RF energy from said RF waveguide and transmitting RF energy into said RF heating chamber. 5. The RF heating system of claim 4, wherein the broadest wall of said RF launcher is oriented substantially perpendicular to the direction of propagation of said articles through said RF heating chamber. 6. The RF heating system of claim 1, further comprising one or more dielectric field shapers receive in said RF heating chamber. 7. The RF heating system of claim 6, wherein the dielectric constant of said dielectric field shapers is less 20. 8. The RF heating system of claim 1, wherein said convey system comprises a dielectric nest for receiving said articles. 9. The RF heating system of claim 8, wherein said dielectric nest has a dielectric constant within 25% of the dielectric constant of said articles. 10. The RF heating system of claim 1, further comprising a pre-heating zone upstream of said RF heating zone. 11. The RF heating system of claim 10, further comprising a cooling zone downstream of said RF heating zone. 12. The RF heating system of claim 11, further comprising a hold zone located between said RF heating zone and said cooling zone. 13. A process for heating a plurality of articles using radio frequency (RF) energy, said process comprising: (a) passing RF energy through an RF waveguide substantially filled with a liquid; (b) introducing RF energy into an RF heating chamber substantially filled with said liquid; and (c) heating articles conveyed through said RF heating chamber using RF energy. 14. The process of claim 13, wherein said liquid in said waveguide and said RF heating chamber is water. 15. The process of claim 13, wherein said liquid in said waveguide and said RF heating chamber has a conductivity of less than 50 mS/m. 16. The process of claims 13, further comprising supplying RF energy to said RF waveguide via a coaxial conductor. 17. The process of claim 16, further comprising transmitting RF energy into said RF waveguide using a coax-to-waveguide transition received in said RF waveguide and coupled to said coaxial conductor. 18. The process of claim 13, further comprising transmitting RF energy from said RF waveguide to said RF heating chamber via an RF launcher substantially filled with said liquid. 19. The process of claim 18, wherein the broadest wall of said RF launcher is oriented substantially perpendicular to the direction of propagation of said articles through said RF heating chamber. 20. The process of claim 13, wherein RF energy is supplied to said RF heating chamber by opposing RF launchers."
  ],
  "description_excerpt": "The present invention relates generally to systems that use radio frequency (300 KHz-300 MHz) energy to heat articles.\n\nElectromagnetic radiation is a known mechanism for delivering energy to an object. The ability of electromagnetic radiation to penetrate and heat an object in a rapid and effective manner has proven advantageous in many chemical and industrial processes. In the past, radio frequency (RF) energy has been used to heat articles by, for example, induction heating or dielectric heating. However, the use of RF energy to heat articles can have some drawbacks. For example, the wavelength of RF energy can make it difficult to transmit and launch RF energy in an efficient manner. The present invention involves discoveries for minimizing and/or eliminating many of the drawbacks conventionally associated with the use of RF energy to heat articles.\n\nCertain embodiments of the present invention provide a radio frequency (RF) heating system that heats a plurality of articles with improved effectiveness and efficiency. The heating provided by the RF heating system can be used to pasteurize or sterilize the articles.",
  "cpc": [
    "H05B 6/707",
    "H05B 6/60",
    "H05B 6/701",
    "H05B 6/78"
  ],
  "ipc": [
    "H05B 6/70",
    "H05B 6/78"
  ],
  "inventors": [
    "Harold Dail Kimrey, JR."
  ],
  "filing_date": "2015-10-23",
  "publication_date": "2016-04-28",
  "priority_date": "2014-10-23",
  "application_number": "US-201514921650-A",
  "family_id": "55761652",
  "cited_by_count": 21,
  "citations": [
    "US5487873A",
    "US5609820A",
    "US5914014A"
  ]
}