Method and apparatus for sterilizing a liquid solution using radio-frequency
Process, and system, for sterilization of a product constituted by a non-distilled or demineralized liquid solution ( 3 ) contained in a rigid and/or flexible container ( 2 ). The process provides for at least one step of heating via capacitive supply of high-frequency current, with electrodes with facing surface of a closed-circuit electrode system ( 1 ) on the product, followed by a step of cooling with interruption of the supplied current; during at least part of the heating step, a counter-pressure pressure (P 2 ) is supplied and acts inside the system ( 1 ) and on the product being treated.
1. A method of sterilizing a product constituted by a non-distilled or demineralized liquid solution contained in a rigid and/or flexible container, the method comprising:
heating by capacitive supply of high-frequency current, from electrodes in a closed-circuit electrode system, wherein said electrodes face a surface of said product; and
after the heating, cooling with interruption of the supplied current,
wherein during at least part of said heating, a counter-pressure is supplied and acts inside the system and on the product being treated.
2. The method according to claim 1 , wherein during at least part of said heating, the closed-circuit electrode system is maintained united by an external pressure.
3. The method according to claim 2 , wherein during said heating, the container is maintained in contact with the surfaces of half-shells forming an internal chamber and the external pressure acts on heads of the container or on closure caps of the container.
4. The method according to claim 1 , wherein said heating reaches at least a sterilization temperature.
5. The method according to claim 2 , wherein said pressures are also maintained during at least part of said cooling.
6. The method according to claim 1 , wherein an amount of dispersed energy is minimized, by controlling and fixing a strictly constant temperature for the liquid circulation of the electrode and a counter-electrode, the system electrodes being maintained at a temperature between 35° C. and 60° C.
7. An electrode system for actuating the method of sterilization of a product constituted by a non-distilled or demineralized liquid solution contained in a rigid and/or flexible container and according to claim 1 , the electrode system comprising:
two half-shells that are configured to be coupled together and closed on each other, shaped in a manner to define at least one internal chamber shaped to contain at least one container and a liquid solution of the container to be sterilized, said half-shells being respectively a power-supplied electrode and a counter-electrode at reference potential;
a plurality of ducts, which enter inside the chamber through a respective inlet hole, from outside the system, said ducts being connected to at least one supply device configured to supply the counter-pressure pressure in the at least one internal chamber;
at least one perimeter gasket on at least one of the two half-shells configured to maintain the two half-shells galvanically isolated and to oppose the counter-pressure pressure; and
a high-frequency generator connected to said two half-shells.
8. The system according to claim 7 , further comprising a compaction device configured to press on the two half-shells.
9. The system according to claim 7 , further comprising a mechanical clamping device configured to shut the two half-shells.
10. The system according to claim 7 , wherein said two half-shells comprise a plurality of cavities configured to allow the passage of a fluid.