Isostatic press for high pressure treatment
View Patent ↗The present invention relates to an isostatic press for high pressure treatment of a product having a temperature below 0° C., said isostatic press comprising a pressure chamber adapted to contain a first pressure medium, and a container which is placeable in the pressure chamber. The container which is placeable in the isostatic press is adapted to hold the product and a second pressure medium, the container being closable to keep the first pressure medium separated from fluid communication with the second pressure medium. The container is further provided with a pressure transfer device adapted to transfer pressure from the first pressure medium to the second pressure medium, and a body which is made of a material with low adiabatic heat emission relative to adjoining substances, so that the body from adjoining substances absorbs heat, which is generated by adiabatic temperature rise during the high pressure treatment. The invention also relates to a method, a container, and a plant for high pressure treatment of a product having a temperature below 0° C. by means of an isostatic press.
1. A method for high pressure treatment of a product by means of an isostatic press comprising a pressure chamber adapted to hold a first pressure medium, comprising the steps of:
providing at least one closed container which holds a second pressure medium and a product whose temperature is below 0° C.;
placing the container in the pressure chamber of the isostatic press;
pressurizing the pressure chamber by means of the first pressure medium;
transferring a pressure change of the first pressure medium to the second pressure medium to subject the product held in the closed container to high pressure treatment; and
keeping the temperature of the product below 0° C. throughout the high pressure treatment by absorbing heat which is generated by adiabatic temperature rise during the high pressure treatment.
2. The method as claimed in claim 1 , further comprising keeping the product in a frozen state throughout the high pressure treatment.
3. The method as claimed in claim 2 , further comprising, if the product reaches a temperature where there is a phase change from solid phase to liquid phase, keeping the product frozen throughout the high pressure treatment by utilizing consumption of melting heat.
4. The method as claimed in claim 1 , further comprising counteracting thermal transfer between the first pressure medium and the second pressure medium by selecting a container provided with thermal insulation.
5. The method as claimed in claim 1 , further comprising counteracting, during the high pressure treatment, by means of a body arranged in the container thermal passing of emitted adiabatic heat from the insulation, due to compression during high pressure treatment, to the second pressure medium.
6. The method as claimed in claim 5 , further comprising absorbing said emitted adiabatic heat from the insulation by selecting a container where the body is positioned between the insulation and the second pressure medium, the body constituting at least part of the container wall.
7. The method as claimed in claim 1 , further comprising transferring the pressure of the first pressure medium to the second pressure medium by compressing the second pressure medium in the container so that pressure equalization is achieved between the first pressure medium and the second pressure medium.
8. The method as claimed in claim 1 , further comprising cooling the container and the second pressure medium to a temperature below 0° C.
9. The method as claimed in claim 8 , further comprising placing in the cooled container the product having a temperature below 0° C.
10. The method as claimed in claim 1 , further comprising discharging a possible residual volume of air from the container holding the product and the second pressure medium before the pressure chamber is pressurized.
11. The method as claimed in claim 1 , further comprising subjecting the product to high pressure treatment for 0.5-20 min.
12. The method as claimed in claim 1 , further comprising subjecting the product to high pressure treatment at a pressure of 2000-15000 bar.
13. The method as claimed in claim 1 , further comprising decompressing the high pressure press and then removing the container from the pressure chamber after the high pressure treatment.
14. An isostatic press for high pressure treatment of a product having a temperature below 0° C., comprising:
a pressure chamber adapted to contain a first pressure medium;
a container which is placeable in the pressure chamber and which is adapted to hold the product and a second pressure medium; and
the container being closable to keep the second pressure medium separated from the first pressure medium and being provided with a pressure transfer device for transfer pressure from the first pressure medium to the second pressure medium, and the container comprising a body which is made of a material having low adiabatic heat emission relative to adjoining substances, so that the body from adjoining substances absorbs heat which is generated by adiabatic temperature rise during the high pressure treatment.
15. The isostatic press as claimed in claim 14 , wherein the body constitutes at least part of a container wall of the container.
16. The isostatic press as claimed in claim 15 , wherein the container wall comprises an inner wall round the outside of which a substance in the form of an insulation is arranged to counteract thermal transfer between the first pressure medium and the second pressure medium, the body constituting at least part of the inner wall, said body counteracting thermal passing of adiabatic heat emission from the insulation, due to compression during the high pressure treatment, to the second pressure medium and the product.
17. The isostatic press as claimed in claim 16 wherein the container is arranged with an outer wall and the insulation is arranged between the inner and the outer wall.
18. The isostatic press as claimed in claim 16 wherein the inner wall of the container is substantially rigid and at least part of the pressure transfer device of the container is movably arranged relative to said inner wall to enable a change of volume of the second pressure medium for the purpose of eliminating a pressure difference between the first pressure medium and the second pressure medium.
19. The isostatic press as claimed in claim 16 wherein the inner wall is made of metal.
20. The isostatic press as claimed in claim 16 wherein the inner wall has a thickness which is at least 5 mm.
21. The isostatic press as claimed in claim 16 wherein the insulation is made of a polymer.
22. The isostatic press as claimed in claim 16 wherein the insulation has a thickness which is at least 5 mm.
23. The isostatic press as claimed in claim 14 wherein the pressure transfer device is arranged as a loose piston adapted to transfer a pressure change in the first pressure medium to the second pressure medium, and to separate the first pressure medium from fluid communication with the second pressure medium.
24. The isostatic press as claimed in claim 14 wherein the pressure transfer device is arranged as a flexible membrane adapted to transfer a pressure change in the first pressure medium to the second pressure medium and to separate the first pressure medium from fluid communication with the second pressure medium.
25. The isostatic press as claimed in claim 14 wherein a plurality of containers can be placed in the same pressure chamber of the isostatic press for simultaneous treatment of the product in each container.
26. The isostatic press as claimed in claim 14 wherein a valve is arranged on the container to enable discharge of a possible residual volume of air in the container when the container holds the product and the second pressure medium.
27. The isostatic press as claimed in claim 14 wherein the second pressure medium is a liquid with a freezing point below 0° C.
28. The isostatic press as claimed in any one claim 14 wherein the first pressure medium is a liquid.
29. A plant for high pressure treatment of products having a temperature below 0° C., comprising:
a freezing device, such as a freezing chamber; and
an isostatic press comprising a pressure chamber adapted to contain a first pressure medium, a container which is placeable in the pressure chamber and which is adapted to hold the product and a second pressure medium, the container being closable to keep the second pressure medium separated from the first pressure medium and being provided with a pressure transfer device for transfer pressure from the first pressure medium to the second pressure medium, and the container comprising a body which is made of a material having low adiabatic heat emission relative to adjoining substances so that the body from adjoining substances absorbs heat which is generated by adiabatic temperature rise during the high pressure treatment.
30. A container adapted to subject, by means of an isostatic press, a product having a temperature below 0° C., which is placeable in the container, to high pressure treatment, comprising:
a closure adapted to separate the inside of the container from the surroundings of the container;
a pressure transfer device for transferring pressure from the surroundings of the container to the inside of the container; and
a body which is made of a material having low adiabatic heat emission relative to adjoining substances, so that the body from adjoining substances absorbs heat which is generated by adiabatic temperature rise during the high pressure treatment, wherein
the body constitutes at least part of a container wall of the container and the container wall comprises an inner wall round the outside of which a substance in the form of an insulation is arranged to counteract thermal transfer between the surroundings of the container and the inside of the container, the body constituting at least part of the inner wall, said body counteracting thermal passing of adiabatic heat emission from the insulation, due to compression during the high pressure treatment, to the inside of the container.
31. The container as claimed in claim 30 wherein the container is arranged with an outer wall and the insulation is arranged between the inner and the outer wall.
32. The container as claimed in claim 30 wherein the inner wall of the container is substantially rigid and at least part of the pressure transfer device of the container is movably arranged relative to said inner wall to enable a change of volume of the inner volume of the container for the purpose of eliminating a pressure difference between the surroundings of the container and the inside of the container.
33. The container as claimed in claim 30 , wherein the pressure transfer device is arranged as a loose piston adapted to transfer a pressure change of the surroundings of the container to the inside of the container and to separate the inside of the container from the surroundings of the container.
34. The container as claimed in claim 30 wherein the pressure transfer device is arranged as a flexible membrane adapted to transfer a pressure change of the surroundings of the container to the inside of the container, and to separate the inside of the container from the surroundings of the container.
35. The container as claimed in claim 30 wherein the inner wall is made of metal.
36. The container as claimed in claim 30 wherein the inner wall has a thickness which is at least 5 mm.
37. The container as claimed in claim 30 wherein the insulation is made of a polymer.
38. The container as claimed in claim 30 wherein the insulation has a thickness which is at least 5 mm.
39. The container as claimed in claim 30 wherein a valve is arranged on the container to enable discharge of a possible residual volume of air in the container when the container holds the product and a pressure medium.
40. The container as claimed in any one of claim 30 wherein the container is adapted to transfer, by the pressure transfer device, a liquid pressure from the outside of the container to a liquid on the inside of the container, said liquid having a freezing point below 0° C.