Device and method for pasteurizing and/or sterilizing particulate material

Patent metadata

Field	Value
Publication number	US-11963540-B2
Application number	US-201916970806-A
Country	US
Kind code	B2
Filing date	Feb 20, 2019
Priority date	Feb 20, 2018
Publication date	Apr 23, 2024
Grant date	Apr 23, 2024

Abstract

A device (10) for pasteurizing and/or sterilizing particulate material. The device (10) includes: an outer housing (40); a material inlet (43); a material outlet (44); a material guide channel (41) for guiding the material through the device (10) to the material outlet (44); at least one electron source (20) for generating an electron beam; and a treatment zone (19), located in the material guide channel (41), for pasteurizing and/or sterilizing while the material is free falling. The device (10) has at least one inner shielding section (51, 52) disposed within the outer housing (40) and enclosing the material guide channel (41) for shielding off radiation produced during treatment. A method for pasteurizing and/or sterilizing particulate material using such a device (10) is also disclosed which includes: a) generating an electron beam, and b) pasteurizing and/or sterilizing the material, while the material is free falling in the treatment zone (19).

First claim

The invention claimed is:

1. An apparatus for pasteurizing and/or sterilizing particulate material, the apparatus comprising:
an outer casing,
a material inlet,
a material outlet,
a material guide channel in which the material can be guided from the material inlet along a material guide direction through the apparatus to the material outlet,
at least one electron source arranged within the housing for generating an electron beam, and
a treatment zone arranged in the material guide channel in which the material can be pasteurized and/or sterilized by means of the electron beam,
wherein the apparatus has at least one inner shielding arranged inside the outer housing and enclosing the material guide channel, and the inner shielding has at least one shielding element for shielding radiation produced during the treatment;
wherein the housing has at least one opening which can be closed by at least one closure element associated therewith, and the closure element contains at least one of the shielding elements on an inner side.

2. The apparatus according to claim 1 , wherein the material guiding channel has at least one channel section in which the inner shielding encloses in a labyrinth-like manner.

3. The apparatus according to claim 2 , wherein the material guide channel contains a material inlet channel in which the material can be guided from the material inlet to the treatment zone, and at least one inner shielding encloses the material inlet channel in a labyrinth-like manner.

4. The apparatus according to claim 2 , wherein the material guide channel contains a material outlet channel in which the material can be guided from the treatment zone to the material outlet, and at least one inner shielding encloses the material outlet channel in a labyrinth-like manner.

5. The apparatus according to claim 1 , wherein at least one shielding includes a static first shielding element and the shielding element of the closure member forms a second shielding element, and the first shielding element and the second shielding element, in a closed position of the closure element in which the closure element closes the opening associated therewith, together enclose the material guide channel.

6. The apparatus according to claim 5 , wherein the first shielding element and the second shielding together enclose the material guide channel in a labyrinth-like manner.

7. The apparatus according to claim 1 , wherein the shielding elements have a multi-layer structure with at least one inner layer of lead and two outer layers of another material.

8. The apparatus according to claim 1 , wherein the material guide channel is delimited by wall elements of which at least one is connected or movably connectable to the housing.

9. The apparatus as claimed in claim 8 , wherein the at least one wall element is releasably connected or connectable to the housing.

10. The apparatus as claimed in claim 1 , wherein the treatment zone is arranged such that the material can be pasteurized and/or sterilized in a free-falling manner.

11. The apparatus as claimed in claim 1 , wherein the inner shielding encloses the material guide along the material guide direction.

12. A method for pasteurizing and/or sterilizing particulate material with an apparatus according to claim 1 , in which the method comprises the following steps:
a) generating an electron beam by the at least one electron source, and
b) pasteurizing and/or sterilizing the material by the electron beam in the treatment zone.

13. The method according to claim 12 , wherein the material moves through the treatment zone at a velocity which is in a range from 1 ms to 5 ms.

14. The method according to claim 12 , wherein the electrons of the electron beam have an energy which is in a range from 80 keV to 300 keV.

15. The method according to claim 12 , wherein the material is exposed to the electron beam for a treatment time ranging from 5 ms to 25 ms.

16. The method according to claim 12 , wherein the material is exposed by the electron beam to a radiation dose which is in the range from 1 kGy to 45 kGy.

17. The method according to claim 12 , wherein the electron beam in the treatment zone has an average current density which is in the range from 10 15 s −1 cm −2 to 2.77 10 15 s −1 cm −2 .

18. The method according to claim 12 , wherein the material, in step b), is pasteurized and/or sterilized in a free-falling manner.

19. The method according to claim 12 , where the material is selected from the group consisting of:
foods,
pet food, feed for ruminants, poultry, aquatic animals or pets, or compound feed, or
plastic.

Assignees

• Buehler Ag

Inventors

• Currie Alasdair
• Hersche Martin

Classifications

• A23B2/503 Primary

  with corpuscular or ionising radiation, i.e. X, alpha, beta or omega radiation · CPC title

• A23L3/263 Primary

  Human Necessities · mapped topic

• A23B9/06

  Preserving by irradiation or electric treatment without heating effect · CPC title

• A23K30/00

  Processes specially adapted for preservation of materials in order to produce animal feeding-stuffs · CPC title

• A61L2/087 Primary

  Particle radiation, e.g. electron-beam, alpha or beta radiation · CPC title