Pressurized heating system with enhanced pressure locks

• US 9,271,338 B2
• Filed: 03/13/2013
• Issued: 02/23/2016
• Est. Priority Date: 03/14/2012
• Status: Active Grant

• Current Assignee: Microwave Materials Technologies, Inc.
• Original Assignee: Microwave Materials Technologies, Inc.
• Inventors: Kimrey, Harold Dail Jr., Cunningham, Gregory Eugene
• Primary Examiner(s): Jennison, Brian
• Application Number:
  US13/800,023
• Publication Number:
  US 20130240508A1
• Time in Patent Office: 1,077 Days
• Field of Search: 219/700, 219/762, 219/702
• US Class Current: 1/1
• CPC Class Codes: A23L 3/01 using microwaves or dielectric heating
• CPC Class Codes: A23L 3/02 by heating materials in packages which are progressively transported, continuously or stepwise, through the apparatus
• CPC Class Codes: A23V 2002/00 Food compositions, function of food ingredients or processes for food or foodstuffs
• CPC Class Codes: A61B 90/70 Cleaning devices specially adapted for surgical instruments
• CPC Class Codes: A61L 2/04 Heat A61L2/08 takes precedence
• CPC Class Codes: A61L 2/12 Microwaves
• CPC Class Codes: A61L 2202/21 Pharmaceuticals, e.g. medicaments, artificial body parts
• CPC Class Codes: A61L 2202/24 Medical instruments, e.g. endoscopes, catheters, sharps
• CPC Class Codes: A61L 2202/26 Textiles, e.g. towels, beds, cloths
• CPC Class Codes: B65B 55/06 by heat
• CPC Class Codes: H01L 21/67201 characterized by the construction of the load-lock chamber
• CPC Class Codes: H05B 6/68 for monitoring or control
• CPC Class Codes: H05B 6/70 Feed lines
• CPC Class Codes: H05B 6/78 Arrangements for continuous movement of material
• CPC Class Codes: H05B 6/782 wherein the material moved is food
• CPC Class Codes: H05B 6/80 Apparatus for specific applications stoves or ranges F24C7/02

Abstract

A microwave heating system configured to heat a plurality of articles and a process for using the same are provided. The microwave heating system includes a liquid-filled thermalization zone, a liquid-filled microwave heating zone, and a pressure lock system disposed therebetween. The pressure lock system includes a pair of locking gate valves and a pressure adjustment chamber configured to transition the articles being heated from the thermalization zone to the microwave heating zone, which may be operated at different pressures.

Claims

1. A microwave heating system for heating a plurality of articles, said microwave heating system comprising:

a liquid-filled thermalization chamber;

a liquid-filled microwave chamber, wherein said microwave chamber is configured to operate at a higher pressure than said thermalization chamber; and

a pressure lock system disposed between said thermalization chamber and said microwave chamber,

wherein said pressure lock system comprises a pressure adjustment chamber, a first locking gate valve, and a second locking gate valve,

wherein said first locking gate valve is coupled between said thermalization chamber and said pressure adjustment chamber,

wherein said second locking gate valve is coupled between said pressure adjustment chamber and said microwave chamber.

2. The system of claim 1, further comprising first and second equilibration valves, wherein said first equilibration valve selectively connects said thermalization and pressure adjustment chambers, wherein said second equilibration valve selectively connects said microwave and pressure adjustment chambers.

3. The system of claim 1, further comprising first and second check valves respectively coupled to said first and second locking gate valves.

4. The system of claim 1, further comprising a platform disposed in said pressure adjustment chamber and configured to support said articles.

5. The system of claim 1, further comprising a thermalization convey system and a microwave convey system, wherein said thermalization convey system is configured to convey said articles through said thermalization chamber toward said pressure adjustment chamber, wherein said microwave convey system is configured to convey said articles through said microwave chamber away from said pressure adjustment chamber.

6. The system of claim 5, further comprising an automatic article transfer system comprising first and second article transfer devices, wherein said first article transfer device is configured to transfer said articles from said thermalization convey system, through said first locking gate valve, and into said pressure adjustment chamber, wherein said second article transfer device is configured to transfer said articles from said pressure adjustment chamber, through said second locking gate valve, and into said microwave chamber.

7. The system of claim 6, wherein at least a portion of said first and/or said second article transfer devices are configured to be stationary.

8. The system of claim 6, wherein at least a portion of said first and/or said second article transfer devices are configured to extend and/or retract.

9. The system of claim 8, wherein said first and/or said second article transfer devices are disposed within said pressure adjustment chamber and are configured to extend into said thermalization chamber and/or said microwave chamber to transport articles into and/or out of said pressure adjustment chamber.

10. The system of claim 8, wherein said first and/or said second article transfer devices are disposed within said thermalization chamber and/or said microwave chamber and are configured to extend into said pressure adjustment chamber to transport articles into and/or out of said pressure adjustment chamber.

11. The system of claim 6, further comprising an automatic control system coupled to said first and second locking gate valves and said first and second article transfer systems, wherein said control system is programmed to control said locking gates and transfer systems to facilitate automatic transfer of said articles from said thermalization chamber to said microwave chamber via said pressure lock system.

12. The system of claim 11, further comprising first and second equilibration valves, wherein said first equilibration valve selectively connects said thermalization and pressure adjustment chambers, wherein said second equilibration valve selectively connects said microwave and pressure adjustment chambers, wherein said control system is operably coupled to said first and second equilibration valves, wherein said control system is programmed to automatically open and close said equilibration valves in coordination with the control of said article transfer systems and said gate valves to thereby facilitate pressure adjustment in said pressure adjustment chamber.

13. The system of claim 1, further comprising a liquid-filled holding chamber configured to receive the heated articles exiting said liquid-filled microwave chamber and a liquid-filled quench zone configured to receive the articles withdrawn from the holding chamber.

14. The system of claim 13, further comprising a second pressure lock system comprising a second pressure adjustment chamber, a third locking gate valve, and a fourth locking gate valve, wherein said second pressure lock system has a similar configuration as said pressure lock system, wherein said second pressure lock system is disposed downstream of said holding zone.

15. The system of claim 14, wherein said quench zone includes a high pressure portion and a low pressure portion, wherein said third locking gate valve is coupled between said high pressure portion of said quench zone and said second pressure adjustment chamber and said fourth locking gate valve is coupled between said pressure adjustment chamber and said low pressure portion of said quench zone.

16. The system of claim 15, wherein each of said high pressure portion and said lower pressure portion of said quench zone are liquid-filled.

17. The system of claim 1, wherein said thermalization chamber and/or said microwave chamber are configured to be operated at a pressure of at least 15 psig.

18. The system of claim 1, wherein said microwave heating system is configured to pasteurize and/or sterilize said articles.

19. The system of claim 18, wherein said articles comprise packaged foodstuffs and said microwave heating system is configured to sterilize said packaged foodstuffs at a rate of at least 20 packages per minute per convey line.

20. A process for heating a plurality of articles in a microwave heating system, said process comprising:

(a) passing a plurality of articles through a liquid-filled thermalization zone to thereby provide a plurality of thermalized articles;

(b) introducing at least a portion of said thermalized articles into a pressure adjustment zone, wherein said pressure adjustment zone is at least partially defined between a first and a second locking gate valve, wherein said first locking gate valves is in a first open position during at least a portion of said introducing;

(c) after said thermalized articles have been introduced into said pressure adjustment zone, shifting said first locking gate valve from said first open position to a first closed position to thereby substantially isolate said pressure adjustment zone from said thermalization zone;

(d) shifting said second locking gate valve from a second closed position to a second open position to allow said articles to be transferred from said pressure adjustment zone to a liquid-filled microwave heating zone; and

(e) after said articles have been removed from said pressure adjustment zone, shifting said second locking gate valve from said second open position back to said second closed position to thereby re-isolate said pressure adjustment zone from said microwave heating zone.

21. The process of claim 20, wherein the operating pressure of said thermalization zone is lower than the operating pressure of said microwave heating zone.

22. The process of claim 20, wherein said introducing of step (b) includes shifting said first locking gate valve from said first closed position, wherein said thermalization zone and said pressure adjustment zone are substantially isolated from one another, to said first open position and transporting said articles through a flow-through opening defined within or by said first locking gate valve and into said pressure adjustment zone.

23. The process of claim 20, further comprising prior to said shifting of step (c), opening a first equalization valve fluidly connecting said thermalization zone with said pressure adjustment zone and allowing the pressures of said thermalization zone and said pressure adjustment zone to substantially equalize before shifting said first locking gate valve into said first open position.

24. The process of claim 23, further comprising prior to said shifting of step (d), opening a second equalization valve fluidly connecting said pressure adjustment zone and said microwave heating zone and allowing the pressure of said pressure adjustment zone and said microwave heating zone to substantially equalize before shifting said second locking gate valve into said second open position.

25. The process of claim 24, further comprising closing said first equalization valve after said shifting of said first locking gate valve in step (c), but prior to opening said second equalization valve;

and closing said second equalization valve after said shifting of step (e).

26. The process of claim 20, wherein at least a portion of said introducing of step (b) is carried out using an automatic article transfer device.

27. The process of claim 26, wherein at least a portion of said automatic article transfer device is disposed within said pressure adjustment zone, wherein said introducing of step (b) includes extending at least a portion of said automatic article transfer device from said pressure adjustment zone into said thermalization zone and withdrawing the extended portion of said article transfer device back into said pressure adjustment zone to introduce said articles therein.

28. The process of claim 20, further comprising repeating steps (a) through (e) with another plurality of articles.

29. The process of claim 28, wherein said plurality of articles are at least partially contained within a first article carrier and said another plurality of articles are at least partially contained within a second article carrier, wherein said second article carrier is being passed through said thermalization zone while said first article carrier is being removed from said pressure adjustment zone, wherein said second article carrier is introduced into said pressure adjustment zone immediately after said first article carrier is removed.

30. The process of claim 20, wherein said articles comprise a plurality of packaged foodstuffs, medical fluids, or medical instruments and wherein said microwave heating system has a production rate of at least 20 packages per convey line.