Microwave sterilization or pasteurization

Patent metadata

Field	Value
Publication number	US-11140913-B2
Application number	US-201815943751-A
Country	US
Kind code	B2
Filing date	Apr 3, 2018
Priority date	May 7, 2014
Publication date	Oct 12, 2021
Grant date	Oct 12, 2021

Abstract

Various embodiments of processing systems and components for sterilization or pasteurization and associated methods of operation are described herein. For example, a method of sterilization or pasteurization includes immersing an item in an immersion fluid, and the immersed item is subject to a hydrostatic pressure of the immersion fluid. The method also includes applying microwave energy to the item while the item is immersed in the immersion fluid and subject to the hydrostatic pressure of the immersion fluid. The hydrostatic pressure of the immersion fluid prevents the water content of the item from causing steam explosion in the item while the microwave energy is applied. The method further includes heating the item immersed in the immersion fluid to a target temperature with the applied microwave energy, the target temperature being sufficient to achieve sterilization or pasteurization of the item.

First claim

We claim:

1. A sterilization and/or pasteurization system, comprising:
a pre-heating section;
a heating section;
a post-heating section;
openable and closeable dividers separating the pre-heating section from the heating section, and separating the heating section from the post-heating section; and
a plurality of individual, separate transport carriers sized to pass through the openable and closeable dividers,
wherein the pre-heating section is connected to the heating section, and the heating section is connected to the post-heating section, and each of the plurality of individual, separate transport carriers is configured to be
placed in the pre-heating section,
transported through the pre-heating section to the heating section,
transported through the heating section to the post-heating section, and
removed from the post-heating section,

wherein the pre-heating section, the heating section, and the post-heating section each are filled or fillable with water,
wherein each of the plurality of individual, separate transport carriers have a top and bottom, front and back, and left and right sides and define a space between the top and bottom, the front and back, and the left and right sides for holding one or more items to be sterilized or pasteurized by exposure to microwave emissions,
wherein the heating section is constructed such that each of the plurality of individual, separate transport carriers are subjected to microwave emissions from one or more microwave emitters positioned above and/or below a transport pathway through the heating section through which the plurality of individual, separate transport carriers are passed sequentially with the front of one individual, separate transport carrier adjacent the rear of another individual, separate transport carrier,
wherein each of the pre-heating section and the post-heating section are configured to accommodate several of the plurality of individual, separate transport carriers vertically one above the other with the top of one individual, separate transport carrier adjacent the bottom of another individual, separate transport carrier, and at least one of the pre-heating section and the post-heating section are configured to have a filled fluid level which has a vertical height above a top of the heating section, and
wherein the dividers open and close to allow each of the plurality of individual, separate transport carriers to pass between the pre-heating section and heating section and between the heating section and post-heating section one at a time.

2. The system of claim 1 further comprising one or more heating controls which maintain a different water temperature in each of the pre-heating section, the heating section, and the post-heating section.

3. The system of claim 1 wherein the one or more microwave emitters emit at 915 MHz.

4. The system of any of claim 1 further comprising a holding section in the heating section, wherein the holding section is configured to accommodate several of the plurality of individual, separate transport carriers vertically one above the other.

5. The system of claim 1 wherein each of the one or more items to be sterilized is at a defined location in the space.

Assignees

• Univ Washington State

Inventors

• Tang Juming
• Liu Fang

Classifications

• A23B2/08 Primary

  using microwaves or dielectric heating · CPC title

• H05B6/782

  wherein the material moved is food · CPC title

• A23L29/272

  Gellan · CPC title

• A23V2002/00

  Food compositions, function of food ingredients or processes for food or foodstuffs · CPC title

• H05B2206/044

  Microwave heating devices provided with two or more magnetrons or microwave sources of other kind · CPC title