Mechanically loaded direct air circulation commodity disinfestation chamber

• US 6,171,561 B1
• Filed: 02/12/1998
• Issued: 01/09/2001
• Est. Priority Date: 09/17/1993
• Status: Expired due to Fees

• Current Assignee: Michael R. Williamson
• Original Assignee: University of Hawai'i
• Inventors: Williamson, Michael Ronald, Winkleman, Paul Martin
• Primary Examiner(s): JASTRZAB, KRISANNE MARIE
• Application Number:
  US09/022,711
• Time in Patent Office: 1,062 Days
• Field of Search: 422/1, 422/28, 422/32, 422/40, 422/307, 422/308, 422/105, 422/108, 422/109, 426/419, 426/407, 426/521, 431/24
• US Class Current: 422/307
• CPC Class Codes: A23B 7/0053 by direct or indirect contact with heating gases or liquids
• CPC Class Codes: A23B 9/025 with use of gases

Abstract

A disinfestation treatment chamber for treating fruit, flower and vegetable commodities subject to infestation by quarantine pests. The commodities are disinfested so as to meet quarantine restrictions without adversely affecting the quality of the commodity. The commodity is heated inside of the chamber in hot air having a relative humidity of 30-85% until the temperature of the commodity exceeds the thermal death point temperature of the target pest but is not so high as to adversely affect the quality of the commodity. The temperature of the commodity is held at this temperature until the pest is killed. The commodity is loaded into the treatment chamber in bins onto a low friction conveyor track system which transports the bins from one end of the chamber to the other. The commodities are treated while they are inside of the treatment chamber. After treatment of the commodities, the bins are unloaded using the low friction conveyor track system out of the opposite end of the treatment chamber. The chamber includes a fan/heat exchanger located inside the treatment chamber and positioned under the commodity bins. The space directly above the fan/heat exchanger is left unobstructed during treatment to enhance the airflow through the commodity bins.

Claims

1. A pest disinfestation chamber comprising:

a. a conveyor track confined for transporting bins of fruit or vegetables from a first end of the chamber to a second end of the chamber, the conveyor track coupled to the chamber so as to divide said chamber into upper and lower plenums and so as to provide an air seal between the upper and lower plenums; and

b. an assembly for heating and circulating air within the chamber, said assembly for heating and circulating air coupled to the chamber and positioned inside of the chamber.

2. The pest disinfestation chamber of claim 1 wherein a first and second set of end doors provide a seal against the ends of said bins during treatment of said fruits or vegetables.

3. The pest disinfestation chamber of claim 2 wherein said assembly for heating and circulating air is comprised of an axial fan and heat exchanger.

4. The pest disinfestation chamber of claim 2 wherein said assembly for heating and circulating air is comprised of a reversible fan and heat exchanger.

5. A pest disinfestation device for disinfesting fruit and vegetables comprising a single chamber having a first end, a second end, an interior and an exterior, said chamber comprising:

a. a friction conveyor track for transporting bins of fruit or vegetables which have been loaded through the first end to the second end for unloading after treatment inside the chamber, the friction conveyor track coupled to the chamber so as to divide said chamber into upper and lower plenums and so as to provide an air seal between the upper and lower plenums; and

b. a fan and heat exchanger system positioned under the conveyor track for heating and circulating air within the chamber and through the bins of fruit or vegetables.

6. The pest disinfestation chamber of claim 5 wherein the friction conveyor track forces heated air through the bins and prevents heated air from bypassing the bins.

7. The pest disinfestation chamber of claim 6 wherein a first and second set of end doors provide a seal against said bins during treatment of said fruits or vegetables.

8. The pest disinfestation chamber of claim 5 wherein the fan and heat exchanger system is comprised of an axial fan and heat exchanger.

9. The pest disinfestation chamber of claim 5 wherein the fan and heat exchanger system is comprised of a reversible fan and heat exchanger.

10. A pest disinfestation device comprising a single chamber, said single chamber comprising:

a. a roller-free conveyor track for transporting bins of fruit or vegetables from a first end of the chamber to a second end of the chamber, the conveyor track coupled to the chamber so as to divide said chamber into upper and lower plenums and so as to provide an air seal between the upper and lower plenums; and

b. a system for heating and circulating air within the chamber and through the bins of fruit or vegetables, said system coupled to the chamber and positioned inside of the chamber and under the bins of fruit or vegetables.

11. The pest disinfestation device of claim 10 wherein said roller-free conveyor track comprises a friction track for transporting bins of fruit or vegetables from the first end of the chamber to a second end of the chamber.

12. The pest disinfestation device of claim 11 wherein said roller-free conveyor track forces heated air through the bins and prevents heated air from bypassing the bins.

13. The pest disinfestation device of claim 10 wherein said system for heating and circulating air comprises an axial fan and heat exchanger.

14. The pest disinfestation device of claim 10 wherein said system for heating and circulating air comprises a reversible fan and heat exchanger.

15. A treatment system for disinfesting fruit and vegetables, comprising:

a. a single chamber;

b. a friction conveyor track interior to said chamber and coupled to said chamber so as to divide said chamber into upper and lower plenums and so as to provide an air seal between the upper and lower plenums;

c. a fan and heat exchanger system positioned under the conveyor track and in the middle of said conveyor track for heating and circulating air within the chamber and through the bins of fruit or vegetables; and

d. one or more bins containing fruit or vegetables positioned on said conveyor track, wherein no bins are positioned directly above said fan and heat exchanger system during treatment.