Pressure indicator

• US 20030226411A1
• Filed: 02/07/2003
• Published: 12/11/2003
• Est. Priority Date: 02/08/2002
• Status: Active Grant

• Current Assignee: Hormel Foods Corporation (Hormel Foods)
• Original Assignee: Hormel Foods LLC (Hormel Foods)
• Inventors: Priebe, Thomas E., Minerich, Phillip L., Luna, Paul C., Wolters, Daniel T., Guion, Marie A., Bicek, Andrew D.
• Granted Patent: US 6,799,467 B2
• Time in Patent Office: Days
• US Class Current: 73/866.4
• CPC Class Codes: A23L 5/30 Physical treatment, e.g. electrical or magnetic means, wave energy or irradiation cooking A23L5/10
• CPC Class Codes: G01L 11/00 Measuring steady or quasi-steady pressure of a fluid or a fluent solid material by means not provided for in group G01L7/00 or G01L9/00

Abstract

Pressure is measured inside of a high pressure vehicle. A substance is compressed at a first pressure to create a preform having a first density. The preform is placed inside of a high pressure vessel and subjected to a second pressure, greater than the first pressure. The preform therefore changes in density to a second density, greater than the first density, whereby the second pressure can be determined. The method may also be used in determining the pressure inside of a food product during food processing and a high pressure vessel.

Claims

1. A method of measuring pressure inside of a high pressure vessel, comprising:

a) compressing a substance at a first pressure to create a preform having a first density;

b) placing the preform in the high pressure vessel; and

c) subjecting the preform to a second pressure, greater than the first pressure, thereby changing the preform to a second density, greater than the first density, whereby the second pressure can be determined.

2. The method of claim 1, wherein the substance is plastic so that density change is irreversible.

3. The method of claim 1, wherein the substance has a face-centered cubic structure.

4. A method of monitoring pressure inside of a high pressure vessel during food processing, comprising:

a) placing a food product inside of a high pressure vessel;

b) placing a preform, having a first density, in the high pressure vessel; and

c) subjecting the food product and preform to a high pressure in the vessel, thereby changing the density of the preform, whereby the pressure in the vessel can be determined.

5. The method of claim 4, further comprising placing the preform in the food product, wherein pressure inside of the food product can be determined.

6. The method of claim 4, wherein the substance is plastic so that density change is irreversible.

7. The method of claim 4, the substance has a face-centered cubic structure.

8. A method of measuring pressure inside of a food product, while the food product is subjected to high hydrostatic pressure, comprising:

a) placing a food product inside of a high pressure vessel;

b) placing a preform, having a first density, in the food product; and

c) subjecting the food product and preform to a high pressure in the vessel, thereby changing the density of the preform, whereby the pressure in the food can be determined.

9. The method of claim 8, wherein the second pressure is greater than 100 MPa.

10. The method of claim 9, wherein the second pressure is from 400 MPa to 600 MPa.

11. The method of claim 8, wherein the substance has a face-centered cubic crystal structure.

12. The method of claim 8, wherein the substance is a powder selected from the group consisting of copper, gold, silver, platinum austenite and thorium.

13. The method of claim 8, wherein the substance is a powder selected from the group consisting of copper, gold, silver and platinum.

14. The method of claim 8, wherein the substance is copper.

15. The method of claim 12, wherein the substance has a non-uniform size.

16. The method of claim 12, wherein density change is irreversible.

17. A method of forming a solid shaped body comprising:

a) compressing a face-centered cubic crystal powder at a first pressure to create a preform;

b) moving the preform to a high pressure vessel; and

c) subjecting the preform to a second pressure, greater than the first pressure, to increase density of the preform where the second pressure can be determined.

18. The method of claim 17, wherein the first pressure is at least 25 MPa.

19. The method of claim 18, wherein the second pressure is at least 100 MPa.

20. The method of claim 17, wherein the substance is plastic so that density change is irreversible.

21. A kit for determining pressure in a high pressure vessel, comprising:

a) a preform formed from a plastic material, wherein density changes at pressures greater than 100 MPa are irreversible;

b) the preform formed under a first pressure, having a first density; and

c) instructions for placing the preform in a high pressure vessel at a second pressure, greater than the first pressure, wherein the preform has a second density, thereby enabling the second pressure to be determined.