WO2016136423A1

WO2016136423A1 - Internal surface electron beam irradiation device

Info

Publication number: WO2016136423A1
Application number: PCT/JP2016/053442
Authority: WO
Inventors: 浩一生杉; 武史野田; 福田　直晃
Original assignee: 日立造船株式会社
Priority date: 2015-02-23
Filing date: 2016-02-05
Publication date: 2016-09-01
Also published as: JP2016154571A

Abstract

The present invention provides an internal surface electron beam irradiation device for sterilizing the internal surface of a PET bottle (1) by irradiation with an electron beam (5). The internal surface electron beam irradiation device is provided with an electron beam irradiation nozzle (23) which irradiates the internal surface (3) of the PET bottle (1) with the electron beam (5) while being inserted in the internal space of the PET bottle (1) through an opening (2). The electron beam irradiation nozzle (23) comprises an exit window (31) from which the electron beam (5) exits, a nozzle main body (32) holding the exit window (31), and a corrosion resistant catalyst membrane (33) covering the nozzle main body (32).

Description

Internal electron beam irradiation device

The present invention relates to an inner surface electron beam irradiation apparatus for sterilizing the inner surface of an object to be sterilized such as a container by electron beam irradiation.

Companies that deal with food and drink containers or medical containers will lose their trust from society if they cause food poisoning or medical accidents due to insufficient sterilization of the containers. For this reason, these containers and the like need to be sterilized reliably in advanced countries where safety is important.

Currently, equipment that irradiates a container with an electron beam is used as a facility for surely sterilizing the container. In such equipment, in order to sterilize the outer surface and inner surface of the container reliably, an outer surface electron beam irradiation device that irradiates the outer surface of the container with an electron beam, and an inner surface electron beam irradiation device that irradiates the inner surface of the container with an electron beam And are provided. In the above facilities, when the container is irradiated with an electron beam, the container is surely sterilized, but corrosive gases such as ozone and nitric acid are generated by a chemical reaction by the electron beam. In order to prevent such corrosion of the equipment due to the corrosive gas, a ventilator for promoting the discharge of the corrosive gas is also provided in the equipment.

By the way, the inner surface electron beam irradiation apparatus irradiates the inner surface of the container with an electron beam from the exit window of the electron beam irradiation nozzle while inserting the electron beam irradiation nozzle into the container from the opening. Since the corrosive gas tends to remain inside the container even when the ventilator is operated, the electron beam irradiation nozzle is exposed to the corrosive gas. For this reason, the electron beam irradiation nozzle is more easily corroded than other devices and equipment of the facility. In order to prevent such corrosion, it is conceivable to apply a conventional technique (see, for example, Patent Document 1) to cover the emission window of the electron beam irradiation nozzle with a catalyst film.

Japanese Laid-Open Patent Publication No. 10-142399

However, even with an electron beam irradiation nozzle whose exit window is covered with a catalyst film, the corrosive gas remaining inside the container has a strong oxidizing power and cannot sufficiently prevent corrosion. Moreover, even if corrosion is prevented to some extent at the exit window, the portion other than the exit window (that is, the side surface of the electron beam irradiation nozzle) is easily corroded. For this reason, the electron beam irradiation nozzle to which the above prior art is applied still has a short life. In addition, since corrosive gas with strong oxidizing power remains inside the container, it is dangerous to discharge the container, which is the object of sterilization, outside the facility as it is.

Therefore, an object of the present invention is to provide an inner surface electron beam irradiation apparatus capable of extending the life.

In order to solve the above problems, an inner surface electron beam irradiation apparatus according to claim 1 of the present invention is an inner surface electron beam irradiation apparatus that sterilizes an inner surface of an object to be sterilized with an opening formed by electron beam irradiation,
An electron beam irradiation nozzle for irradiating an inner surface of the sterilization object with an electron beam while being inserted into the sterilization object from the opening is provided,
The electron beam irradiation nozzle includes an emission window that emits an electron beam, a nozzle body that holds the emission window, and a protective film that covers the nozzle body.

Moreover, the inner surface electron beam irradiation apparatus according to claim 2 of the present invention has corrosion resistance on the entire surface of the portion in which the protective film in the inner surface electron beam irradiation apparatus according to claim 1 is inserted into the sterilization object. In addition, the portion inserted into the object to be sterilized has catalytic properties.

Furthermore, in the inner surface electron beam irradiation apparatus according to claim 3 of the present invention, a large number of protective films in the inner surface electron beam irradiation apparatus according to claim 2 are supported on the corrosion resistant layer having corrosion resistance and the outer surface of the corrosion resistant layer. And a catalytic body having catalytic properties.

In addition, the inner surface electron beam irradiation apparatus according to claim 4 of the present invention is such that the corrosion-resistant layer in the inner surface electron beam irradiation apparatus according to claim 3 also has conductivity.
The protective film includes an insulating layer disposed between the corrosion-resistant layer and the nozzle body,
A charging power source for applying a voltage to the corrosion-resistant layer and the nozzle body is provided.

Further, in the inner surface electron beam irradiation apparatus according to claim 5 of the present invention, the charging power source in the inner surface electron beam irradiation apparatus according to claim 4 applies a pulsed voltage to the corrosion-resistant layer and the nozzle body. is there.

An inner surface electron beam irradiation apparatus according to claim 6 of the present invention is the inner surface electron beam irradiation apparatus according to any one of claims 2 to 5, wherein energy for improving the catalytic property of the protection film is applied to the protection film. The energy supply part which supplies to is provided.

According to the inner surface electron beam irradiation apparatus, since the electron beam irradiation nozzle is not corroded by the protective film, the life can be extended.

It is a schematic perspective view which shows the inner surface electron beam irradiation apparatus which concerns on embodiment of this invention. It is a schematic side view which shows the electron beam emitter of the inner surface electron beam irradiation apparatus. It is the partially cutaway side view which expanded the electron beam irradiation nozzle of the electron beam emitter, and the PET bottle in which this electron beam irradiation nozzle is inserted. It is a partially cutaway side view which shows the example in which the same inner surface electron beam irradiation apparatus was provided with the energy supply part.

Hereinafter, an inner surface electron beam irradiation apparatus according to an embodiment of the present invention will be described with reference to the drawings.

First, the outline of the electron beam sterilization equipment provided with the inner surface electron beam irradiation apparatus will be briefly described.

This electron beam sterilization facility is a facility that sterilizes by irradiating an electron beam while conveying an object to be sterilized in which an opening is formed. The sterilization target in which the opening is formed is, for example, a container such as a plastic bottle or a preform body. The preform body is a raw material body before being formed into a PET bottle by blow molding, and has a test tube shape. In the following, for the sake of simplicity, the sterilization object in which the opening is formed will be described as a PET bottle.

The electron beam sterilization facility generally includes a transport device that continuously transports a large number of PET bottles from the upstream side to the downstream side, and an electron beam continuously on the outer surface of the PET bottle transported to the transport device. And an inner surface electron beam irradiation device that continuously irradiates the inner surface of the PET bottle transported to the transport device on the downstream side with the electron beam. In addition, the PET bottles that are insufficiently sterilized by electron beam irradiation need to be discarded as defective products. A reject device that performs this disposal is also provided in the electron beam sterilization facility. Further, corrosive gases such as ozone and nitric acid are generated by the electron beam irradiation. Since this corrosive gas causes corrosion of each device of the electron beam sterilization facility, it must be discharged to the outside of the electron beam sterilization facility. A ventilation device that promotes the discharge is also provided in the electron beam sterilization facility.

Next, the inner surface electron beam irradiation apparatus will be described with reference to FIGS.

As shown in FIG. 1, this inner surface electron beam irradiation device continuously sterilizes the inner surfaces of a large number of PET bottles 1 transported to the circular path 4 by the transport device. The inner surface electron beam irradiation device 10 is positioned above the circular path 4 and is concentric with the circular path 4. A large number of the turntables 11 are arranged on the turntable 11 and positioned immediately above the circular path 4. An electron beam emitter 12.

The turntable 11 rotates so that a certain electron beam emitter 12 is positioned immediately above the PET bottle 1 conveyed to the circular path 4. As shown in FIG. 2, the electron beam emitter 12 mainly includes a vacuum chamber 21 whose inside is a vacuum atmosphere, a fixture 22 for fixing the vacuum chamber 21 to the turntable 11, and a downward direction from the vacuum chamber 21. An extending electron beam irradiation nozzle 23 is included. Although not shown, the vacuum chamber 21 is configured to generate a large number of electrons and accelerate downward by arranging an electron generation source therein. The electron beam irradiation nozzle 23 communicates with the vacuum chamber 21 and has a vacuum atmosphere inside. The electron beam irradiation nozzle 23 emits a large number of electrons accelerated in the vacuum chamber 21 from the lower end as an electron beam. Therefore, in order to sterilize the inner surface of the plastic bottle 1, the electron beam irradiation nozzle 23 is inserted into the interior of the plastic bottle 1 through the opening 2 as shown in FIGS. Must be irradiated with an electron beam. Therefore, an elevating device for inserting the electron beam irradiation nozzle 23 into the inside of the PET bottle 1 from the opening 2 by raising the PET bottle 1 from the circular path 4 is also provided in the electron beam sterilization facility, although not shown. It is done.

Hereinafter, the electron beam irradiation nozzle 23 which is the gist of the present invention will be described in detail.

As shown in FIG. 3, the electron beam irradiation nozzle 23 has, as a conventional configuration, an emission window 31 that emits the electron beam 5 and a cylindrical nozzle body 32 that holds the emission window 31 at the lower end. . The electron beam irradiation nozzle 23 has a characteristic configuration of the present invention, and is a corrosion-resistant catalyst film (an example of a protective film) that covers the entire surface of the nozzle body 32 that is inserted into the interior 3 of the PET bottle 1. 33). The corrosion-resistant catalyst film 33 may cover the nozzle body 32 other than the portion inserted into the interior 3 of the plastic bottle 1. The corrosion-resistant catalyst film 33 has corrosion resistance on the entire surface of the portion inserted into the interior 3 of the PET bottle 1 and also has catalytic properties at the portion inserted into the interior 3 of the PET bottle 1. is there. The portion having the catalytic property may be a portion that is easily exposed to the corrosive gas remaining in the interior 3 of the PET bottle 1 for a relatively long time, specifically, a lower portion of the nozzle body 32. preferable. As shown in FIG. 3, the corrosion-resistant catalyst film 33 is formed on, for example, a corrosion-resistant layer 34 that covers the nozzle body 32 over the entire surface inserted into the interior 3 of the PET bottle 1, and a lower outer surface of the corrosion-resistant layer 34. And a large number of supported catalyst bodies 35. A material having higher corrosion resistance than the nozzle body 32 is used for the corrosion resistant layer 34. In order to increase the probability of contacting the corrosive gas, the large number of catalyst bodies 35 are arranged such that the distance between adjacent ones is constant.

Next, a preferable configuration of the electron beam irradiation nozzle 23 will also be described.

The corrosion-resistant layer 34 and the nozzle body 32 also have conductivity. The corrosion-resistant catalyst film 33 also includes an insulating layer 36 disposed between the corrosion-resistant layer 34 and the nozzle body 32 in order to insulate the corrosion-resistant layer 34 and the nozzle body 32.

The inner surface electron beam irradiation apparatus 10 also includes a charging power source 14 that applies a voltage to the corrosion-resistant layer 34 and the nozzle body 32. The charging power source 14 charges the corrosion-resistant layer 34 positively and charges the nozzle body 32 negatively by applying the voltage. The positively charged corrosion-resistant layer 34 leads the corrosive gas to the catalyst body 35 by attracting the negatively charged corrosive gas by the electron beam 5. Here, the voltage may be constant or pulsed. Since the voltage is pulsed, the corrosive gas is intermittently attracted by the corrosion-resistant layer 34, so that the probability of guiding the corrosive gas to the catalyst body 35 is increased. The negatively charged nozzle body 32 further converges the electron beam 5 passing through the nozzle body 32 toward the axial center side of the nozzle body 32 by repulsive force. Since the number of electrons passing through the unit area is further increased, the electron beam 5 further converged in this way further improves the efficiency of sterilization.

Next, the material of the electron beam irradiation nozzle 23 constituting the inner surface electron beam irradiation apparatus 10 will be described.

The nozzle body 32 is made of a conventionally used material such as stainless steel.

For the corrosion-resistant layer 34 having the above conductivity, a material having higher corrosion resistance than the nozzle body 32, for example, titanium, anodized aluminum or the like is used. In addition to this, the corrosion-resistant layer 34 having conductivity also includes iron, zirconium, molybdenum, rhodium, palladium, silver, tantalum, tungsten, iridium, platinum or gold, oxide, carbide, nitride, or these. An alloy containing two or more types is used. Moreover, the corrosion-resistant layer 34 having conductivity may have a two-layer structure of an inner layer having conductivity and an outer layer having corrosion resistance. In this case, the inner layer having conductivity is copper or the like, and the outer layer having corrosion resistance is fluorine resin or the like.

The catalyst body 35 is made of a simple substance such as titanium, lead, or cobalt, an oxide, or an alloy containing these. In addition, platinum, gold, palladium, rhodium, and iridium are used for the catalyst body 35.

The insulating layer 36 is preferably made of a material having heat resistance and corrosion resistance, such as silicon, silicon oxide, glass, ceramic, or fluorine resin. The insulating layer 36 is preferably porous so that heat generated in the nozzle body 32 is easily released.

Hereinafter, the operation and action of the inner surface electron beam irradiation apparatus 10 will be described.

As shown in FIG. 1, a large number of PET bottles 1 with the opening 2 on the top are continuously transported to the circular path 4 below the inner surface electron beam irradiation device 10 by the transport device. As the individual PET bottles 1 are lifted by the lifting device, as shown in FIG. 2, the electron beam irradiation nozzle 23 is inserted into the inside 3 from the opening 2. When the electron beam irradiation nozzle 23 is inserted into the inside 3 of the PET bottle 1, the electron beam 5 is irradiated from the electron beam irradiation nozzle 23 to the inner surface of the PET bottle 1, as shown in FIG. Of the corrosive gas generated by the irradiation of the electron beam 5, the one in the inside of the PET bottle 1 is not easily discharged to the outside of the electron beam sterilization facility by the ventilator, and much remains as it is. However, the corrosive gas remaining in the inside 3 of the PET bottle 1 is rendered harmless by the catalytic property (specifically, the catalyst body 35) provided in the corrosion-resistant catalyst film 33 of the electron beam irradiation nozzle 23.

Since the corrosive gas remaining in the interior 3 of the PET bottle 1 is rendered harmless, the electron beam irradiation nozzle 23 inserted into the interior 3 of the PET bottle 1 does not corrode. Even if the corrosive gas is not completely detoxified, the electron beam irradiation nozzle 23 inserted into the interior 3 of the PET bottle 1 does not corrode due to the corrosion resistance of the corrosion-resistant catalyst film 33.

On the other hand, corrosive gas is guided to the catalyst body 35 by the electroconductivity of the corrosion-resistant layer 34 and the nozzle body 32, which is a preferable configuration of the electron beam irradiation nozzle 23, the insulating layer 36, and the charging power source 14. As a result, the detoxification of the corrosive gas is promoted, so that the electron beam irradiation nozzle 23 is not further corroded.

Thus, according to the inner surface electron irradiation device, the electron beam irradiation nozzle 23 does not corrode, so the life can be extended. Moreover, since the corrosive gas remaining in the interior 3 of the PET bottle 1 is rendered harmless, the PET bottle 1 can be safely discharged.

In addition, the conductivity of the corrosion resistant layer 34 and the nozzle body 32, the insulating layer 36, and the charging power source 14 promote the detoxification of the corrosive gas. The plastic bottle 1 can be discharged more safely.

In the above embodiment, energy 6 for improving the catalytic property of the corrosion-resistant catalyst film 33 has not been described. However, as shown in FIG. An energy supply unit 16 may be provided to supply any portion that is provided. The energy 6 is, for example, light energy and / or heat energy, and an appropriate one is selected depending on the material of the catalyst body 35. Since the detoxification of the corrosive gas is further promoted by improving the catalytic properties of the corrosion-resistant catalyst film 33, the lifetime can be further increased and the PET bottle 1 can be discharged more safely. .

Moreover, in the said embodiment, although many catalyst bodies 35 were demonstrated as a structure for the said corrosion-resistant catalyst film | membrane 33 to have catalytic property, the said corrosion-resistant layer 34 is covered instead of such a catalyst body 35. FIG. It may be a catalyst layer. Of course, by using the catalyst body 35 instead of the catalyst layer, the material used as the catalyst can be reduced.

Furthermore, although the corrosion-resistant catalyst film 33 has been described as an example of the protective film in the above embodiment, the present invention is not limited to this, and any film that protects the nozzle body 32 may be used.

In addition, in the above-described embodiment, the corrosion-resistant catalyst film 33 has been described as including the corrosion-resistant layer 34 and the catalyst body 35 (preferably also the insulating layer 36). However, the present invention is not limited to this, and the insulating corrosion-resistant film. A catalyst may be supported on a membrane.

Claims

An inner surface electron beam irradiation apparatus for sterilizing the inner surface of an object to be sterilized with an opening formed by electron beam irradiation,
An electron beam irradiation nozzle for irradiating an inner surface of the sterilization object with an electron beam while being inserted into the sterilization object from the opening is provided,
An inner surface electron beam irradiation apparatus, wherein the electron beam irradiation nozzle includes an emission window that emits an electron beam, a nozzle body that holds the emission window, and a protective film that covers the nozzle body.
2. The protective film according to claim 1, wherein the protective film has corrosion resistance on the entire surface of the portion to be inserted into the object to be sterilized, and has catalytic properties at a portion to be inserted into the object to be sterilized. The inner surface electron beam irradiation apparatus described.
The inner surface electron beam irradiation apparatus according to claim 2, wherein the protective film includes a corrosion-resistant layer having corrosion resistance and a catalyst body having a catalytic property supported on the outer surface of the corrosion-resistant layer.
The corrosion resistant layer also has conductivity,
The protective film includes an insulating layer disposed between the corrosion-resistant layer and the nozzle body,
4. The inner surface electron beam irradiation apparatus according to claim 3, further comprising a charging power source for applying a voltage to the corrosion-resistant layer and the nozzle body.
5. The inner surface electron beam irradiation apparatus according to claim 4, wherein the charging power source applies a pulsed voltage to the corrosion-resistant layer and the nozzle body.
The inner surface electron beam irradiation apparatus according to any one of claims 2 to 5, further comprising an energy supply unit configured to supply energy for improving the catalytic property of the protective film to the protective film.