JP2002171949A - Electron beam sterilization method and electron beam sterilizer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electron beam sterilization method and an electron beam sterilizer of low ozone generation levels. SOLUTION: This electron beam sterilization method and an electron beam sterilizer therefor have the following advantages: since an electron beam irradiation zone comes to a negative pressure condition by evacuating a gas therefrom by a relevant means 5, the oxygen concentration of the zone becomes lower, resulting in reduced ozone generation levels; both the inlet side 1a and the outlet side 1b of the zone are fed with a clean air or inert gas from a relevant feed means 6, resulting in positive pressure, therefore preventing bacteria from intrusion from the outside into a clean tunnel 1 or keeping the clean tunnel 1 from recontamination.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electron beam sterilization method and apparatus.

[0002]

2. Description of the Related Art In a device requiring a clean environment, such as a sterilizing device for sterilizing by irradiating an object to be sterilized with an electron beam, for example, a positive pressure is applied to the inside of the device by sucking and discharging clean air into a clean tunnel. The object to be sterilized after the sterilization treatment is prevented from being re-contaminated by coming into contact with the surrounding atmosphere (see Japanese Patent Application Laid-Open No. 11-91942).

[0003]

In the above-mentioned prior art, the electron beam reacts with oxygen in the air to generate ozone. Since ozone has a bactericidal effect and a deodorizing effect, it deteriorates the flavor of spices and other foods that value the flavor. Since the amount of generated ozone is proportional to the amount of oxygen that reacts with the electron beam, there is a problem that when the electron beam irradiation region is set to a positive pressure, an increase in the amount of oxygen that reacts leads to an increase in the amount of ozone generated. Was.

Accordingly, an object of the present invention is to solve the above-mentioned problems and to provide an electron beam sterilization method and an apparatus thereof that generate a small amount of ozone.

[0005]

In order to achieve the above object, an electron beam sterilization method according to the present invention provides an electron beam sterilization method for conveying an object to be sterilized conveyed from a carry-in port to a carry-out port by carrying means provided in a clean tunnel. In the electron beam sterilization method of sterilizing by irradiating the electron beam, the electron beam irradiation area of the clean tunnel is evacuated to a negative pressure, and clean air or an inert gas is supplied to the entrance and exit sides of the electron beam irradiation area. It is supplied to make positive pressure.

[0006] In addition to the above configuration, in the electron beam sterilization method of the present invention, it is preferable that the pressure difference between the negative pressure region and the positive pressure region in the clean tunnel is 100 Pa or more.

An electron beam sterilizer according to the present invention comprises: a clean tunnel; transport means provided in the clean tunnel for transporting an object to be sterilized from an entrance side to an exit side; Electron beam irradiating device, exhaust means provided in the clean tunnel to evacuate the electron beam irradiating area in the clean tunnel to create a negative pressure, and a carry-in port provided in the clean tunnel for the electron beam irradiating area in the clean tunnel Supply means for supplying clean air or inert gas to the side and the outlet side to make it positive pressure.

[0008] In addition to the above configuration, in the electron beam sterilizer of the present invention, it is preferable that the pressure difference between the negative pressure region and the positive pressure region in the clean tunnel is 100 Pa or more.

According to the present invention, the electron beam irradiation area is evacuated by the exhaust means to have a negative pressure, so that the oxygen concentration in the electron beam irradiation area decreases, and as a result, the amount of ozone generated decreases. Since the entrance and exit sides of the electron beam irradiation area are at a positive pressure due to the clean air or inert gas from the supply means, bacteria can be prevented from entering the clean tunnel from the outside and recontaminated. Is done.

[0010]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

FIG. 1 is a conceptual diagram showing an embodiment of an apparatus to which the electron beam sterilization method of the present invention is applied.

The present electron beam sterilizer is a clean tunnel 1
And a pepper 2 (pepper before grinding) 2 provided in the clean tunnel 1 as an object to be sterilized from the entrance 1a to the exit 1
b, an electron beam irradiating device 4 for irradiating the granular pepper 2 in the clean tunnel 1 with an electron beam, and an electron beam irradiating area in the clean tunnel 1 provided in the clean tunnel 1 by exhausting the shadow. It is composed of exhaust means 5 for increasing the pressure and supply means 6 provided in the clean tunnel 1 for supplying clean air to the entrance and exit sides of the electron beam irradiation area in the clean tunnel 1 to produce a positive pressure. It is something.

The exhaust means 5 comprises a pipe 7 connected below the electron beam irradiation area of the clean tunnel 1 and a blower 8 connected to the pipe 7. Preferably, an ozone decomposition catalyst is provided on the exhaust side of the blower 8.

The supply means 6 includes a filter 10 for filtering the air, and a blower 11 for supplying the air filtered by the filter 10 to the carry-in side and the carry-out side of the electron beam irradiation area in the clean tunnel 1. And a blower 11 and a pipe 12 connected to the upper side of the clean tunnel 1.

The conveyor 3 is preferably a conveyor using a mesh belt.

The pressure difference between the negative pressure area AL and the positive pressure area AH in the clean tunnel 1 is preferably set to 100 Pa or more. However, it is necessary that the strength be such that the object 2 to be sterilized is not blown off. The pressure in the negative pressure area AL is preferably atmospheric pressure in order to prevent the sterilization target 2 from being discharged to the outside. The carry-in entrance 1a and the carry-out exit 1b at both ends of the clean tunnel 1 are preferably large enough to allow the object to be sterilized 2 and the conveyor 3 to pass through, and the length of the clean tunnel 1 is preferably several meters or more.

With this configuration, since the electron beam irradiation region has a negative pressure, the oxygen concentration in the electron beam irradiation region decreases, and as a result, the amount of ozone generated decreases. Positive pressure is applied to the entrance 1a side and the exit side 1b of the electron beam irradiation region, so that it is possible to prevent bacteria and the like from entering the clean tunnel 1 from the outside and contaminate the inside of the clean tunnel 1.

In the present embodiment, the case where clean air is supplied into the clean tunnel 1 has been described. However, the present invention is not limited to this, and an inert gas such as nitrogen gas or argon gas is supplied. May be supplied. However, when supplying an inert gas, it is preferable to provide an ejector 13 in the pipe 7 of the exhaust means 5. Further, in the present embodiment, the case where the pepper is used as the object to be sterilized has been described. However, the present invention is not limited to this. )) Is not preferred, and foods that do not soar and tend to lose flavor are preferred.
Containers such as ET bottles and caps may be used.

[0019]

In summary, according to the present invention, the following excellent effects are exhibited.

It is possible to realize the provision of an electron beam sterilization method and an apparatus thereof that generate a small amount of ozone.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram showing an embodiment of an apparatus to which an electron beam sterilization method of the present invention is applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Clean tunnel 2 Object to be sterilized (pepper) 3 Transport means (Conveyor) 4 Electron beam irradiation device 5 Exhaust means 6 Supply means

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Tadahide Shirakawa 3-1-1-15 Toyosu, Koto-ku, Tokyo Ishikawajima Harima Heavy Industries, Ltd. Tokyo Engineering Center (72) Inventor Chieko Uchikoshi 3-1-1 Toyosu, Koto-ku, Tokyo No. 15 Ishikawajima Harima Heavy Industries, Ltd. Tokyo Engineering Center F term (reference) 4B021 LA44 LP07 LP10 LT01 LW07 LW09 4C058 AA21 BB06 DD06 EE26 KK01 KK45

Claims (4)

[Claims] 1. An electron beam sterilization method for irradiating an object to be sterilized conveyed from a carry-in port to a carry-out port with an electron beam to sterilize the object by an electron beam irradiation area of the clean tunnel. And evacuation to a negative pressure, and a positive pressure is supplied to the entrance and exit sides of the electron beam irradiation area by supplying clean air or an inert gas to the electron beam sterilization method. 2. The electron beam sterilization method according to claim 1, wherein a pressure difference between the negative pressure region and the positive pressure region in the clean tunnel is 100 Pa or more. 3. A clean tunnel, transport means provided in the clean tunnel for transporting an object to be sterilized from an entrance side to an exit side, and an electron beam for irradiating the object to be sterilized within the clean tunnel with an electron beam. An irradiation device, an exhaust unit provided in the clean tunnel to exhaust the electron beam irradiation region in the clean tunnel to a negative pressure, and a carry-in side of the electron beam irradiation region in the clean tunnel provided in the clean tunnel And a supply means for supplying clean air or inert gas to the outlet side to make the air positive pressure. 4. The electron beam sterilizer according to claim 3, wherein a pressure difference between the negative pressure area and the positive pressure area in the clean tunnel is 100 Pa or more.