Induction heating system for food containers and method

• US 9,883,551 B2
• Filed: 03/15/2013
• Issued: 01/30/2018
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: Silgan Containers LLC (Silgan Holdings Incorporated)
• Original Assignee: Silgan Containers LLC (Silgan Holdings Incorporated)
• Inventors: Widitora, Alvin, Miller, Douglas C., Sadler, George, Hu, Jianwen, Baker, Gerald J.
• Primary Examiner(s): Angwin, David
• Assistant Examiner(s): Chou, Jimmy
• Application Number:
  US13/832,573
• Publication Number:
  US 20140263286A1
• Time in Patent Office: 1,782 Days
• Field of Search: 219635, 219645, 219647, 219653, 219654, 219646, 219662, 219672, 219673, 219674, 219675, 219676, 219677, 165 61, 165 64, 165 65, 165 58
• CPC Class Codes: H05B 6/06 Control, e.g. of temperature, of power
• CPC Class Codes: H05B 6/107 for continuous movement of material

Abstract

An induction heating system configured to sequentially heat a plurality of filled and sealed food containers is provided. The system includes an induction heating coil defining a lumen having a longitudinal axis. The lumen is configured to receive the containers during heating, and the induction coil is configured to generate an alternating magnetic field causing resistive heating of the container. The system includes a container moving device configured to move containers into the induction heating coil lumen prior to heating, to move containers while within the induction heating coil lumen and to move containers out of the induction heating coil lumen after heating.

Claims

1. A metallic food can heating system configured to heat a plurality of filled and sealed metallic food cans comprising:

an induction heating coil defining an internal lumen having a longitudinal axis, the internal lumen configured to receive the metallic food cans during heating, the induction coil configured to generate an alternating magnetic field causing resistive heating of the metallic material of the food can;

a can moving device configured to move cans into the induction heating coil prior to induction heating, to move cans while within the induction heating coil and to move cans out of the induction heating coil after induction heating;

an electrical induction power supply configured to supply alternating current to the induction heating coil;

a preheating chamber located before the induction heating coil;

a cooling chamber located after the induction heating coil;

a coil cooling system configured to cool the induction heating coil;

a first conduit configured to transfer heat from the cooling chamber to the preheating chamber; and

a second conduit configured to transfer heat from the coil cooling system to the preheating chamber;

wherein each can has a longitudinal axis, wherein each can is positioned within the lumen of the induction coil such that the longitudinal axis of each can is substantially perpendicular to the longitudinal axis of the internal lumen of the induction heating coil.

2. An induction heating system configured to sequentially heat a plurality of filled and sealed food containers comprising:

an unpressurized heating chamber including an induction heating coil defining a lumen having a longitudinal axis, the lumen configured to receive the containers during heating, the induction coil configured to generate an alternating magnetic field causing resistive heating of the container;

a container moving device configured to move containers into the induction heating coil lumen prior to induction heating, to move containers while within the induction heating coil lumen and to move containers out of the induction heating coil lumen after heating;

a passively heated preheating chamber located before the unpressurized heating chamber;

a cooling chamber located after the unpressurized heating chamber; and

a first support structure configured to engage a first end wall of the container and a second support structure configured to engage a second end wall of the container within the induction heating coil lumen during heating of the container, wherein the first and second support structures exert an inwardly directed force on the end walls to resist outward deformation of the end wall during heating.

3. The induction heating system of claim 2 wherein the support structure is made from an electrically non-conductive material.

4. The induction heating system of claim 3 wherein the electrically non-conductive material is a polymer material.

5. The induction heating system of claim 4 wherein the support structure is configured to rotate each container about the longitudinal axis of the container within the induction heating coil lumen during heating of the container.

6. The induction heating system of claim 5 wherein the support structure is configured to rotate each of the containers at a rate between 50 rpm and 600 rpm.

7. An induction heating system configured to sequentially heat a plurality of filled and sealed food containers comprising:

an unpressurized heating chamber including an induction heating coil defining a lumen having a longitudinal axis, the lumen configured to receive the containers during heating, the induction coil configured to generate an alternating magnetic field causing resistive heating of the container;

a container moving device configured to move containers into the induction heating coil lumen prior to induction heating, to move containers while within the induction heating coil lumen and to move containers out of the induction heating coil lumen after heating;

at least one support structure configured to engage an end wall of the container within the induction heating coil lumen during heating of the container, wherein the support structure resists outward deformation of the end wall during heating;

a preheating chamber located before the unpressurized heating chamber;

a cooling chamber located after the unpressurized heating chamber;

a coil cooling system configured to cool the induction heating coil;

a first conduit configured to transfer heat from the cooling chamber to the preheating chamber; and

a second conduit configured to transfer heat from the coil cooling system to the preheating chamber.

8. A metallic food can heating system configured to heat a plurality of filled and sealed metallic food cans comprising:

an induction heating coil defining an internal lumen having a longitudinal axis, the induction coil inducing electric currents to cause resistive heating in metallic food cans contained within the internal lumen, when the electric coil is energized,

a can moving device configured to move cans into the induction heating coil prior to induction heating, to move cans while within the induction heating coil and to move cans out of the induction heating coil after induction heating;

an electrical induction power supply coupled to the induction heating coil and configured to supply alternating current to the induction heating coil; and

a plurality of first support structures configured to engage an upper end wall of each of the plurality of cans, and a plurality of second support structures configured to engage a lower end wall of each of the plurality of cans, wherein the first and second support structures engage the upper and lower end walls of each of the plurality of cans while the cans are within the internal lumen of the induction heating coil, wherein the first and second support structures resist outward deformation of the upper and lower end walls during heating of the plurality of cans;

wherein the plurality of first support structures and the plurality of second structures are configured to exert an inwardly directed force on the upper and lower end walls, respectively, of each of the plurality of cans; and

wherein each can has a longitudinal axis, wherein a majority portion of each can is positioned within the lumen of the induction coil such that the longitudinal axis of each can is substantially perpendicular to the longitudinal axis of the internal lumen of the induction heating coil.