WO2017064740A1

WO2017064740A1 - Sterilizing device

Info

Publication number: WO2017064740A1
Application number: PCT/JP2015/005185
Authority: WO
Inventors: Kenichi Higashiyama; Kenta TOMINAGA; Yuji Hirayama; Kazuki Yoshihara; Toshiaki Iizuka; Satoshi Moriya; Christian Buske; Daniel HASSE
Original assignee: Suntory Holdings Limited; Plasmatreat Gmbh
Priority date: 2015-10-13
Filing date: 2015-10-13
Publication date: 2017-04-20

Abstract

A sterilizing device includes a nozzle (10) for spraying sterilizing agent (70) and a water vapor feeding section (40) for feeding water vapor to the nozzle (10). The nozzle (10) includes a plasma generating section (11), an outlet section (12) and a relaying section (13) connected to the plasma generating section (11) and the outlet section (12). The water vapor feeding section (40) is connected to the relaying section (13). The outlet section (12) sprays, as the sterilizing agent (70), a sterilizing agent 70 containing the plasma fed from the plasma generating section (11) and ROS (Reactive Oxidizing Species) generated through a reaction between the plasma and water vapor to the sterilization object.

Description

STERILIZING DEVICE

This disclosure relates to a sterilizing device for sterilizing a sterilization object such as a cap of a container.

As a method of sterilizing a cap of a container such as a PET bottle as an example of a sterilization object, a sterilizing method is known from Japanese Unexamined Patent Application Publication No. 2013-28398 (Patent Literature 1). Patent Literature 1 describes a method of sterilizing an interior of a container by blowing (spraying) an amount of a sterilizing agent containing hydrogen peroxide into a container or into its cap.

In the case of using sterilizing agent containing hydrogen peroxide as in the sterilizing method described in Patent Literature 1, a cleaning operation needs to be effected after the use of the agent so that any of the sterilizing agent will not remain on the cap. However, elimination of entire sterilizing agent is difficult with such cleaning operation. Thus, there is a risk of some of the sterilizing agent remaining on the cap. Further, in the case of the sterilizing method of Patent Literature 1, the spraying operation of the sterilizing agent and the cleaning operation subsequent thereto are carried out mainly at a high temperature. Thus, in the case of a cap of a PET bottle formed of resin material, various restrictions will be imposed on the sterilizing process in order to avoid excessive thermal contraction or deformation.

Japanese Unexamined Patent Application Publication No. 2013-28398

Accordingly, there remains a desire for realization of a sterilizing device for sterilizing a sterilization object such as a cap to be attached to a bottle, with no risks of remaining of a sterilizing agent on the sterilization object and of excessive thermal contraction or deformation of the sterilization object.

According to this disclosure, there is provided a sterilizing device, the device sterilizing a sterilization object by generating plasma and irradiating the generated plasma to the object, the sterilizing device comprising:
a nozzle for spraying sterilizing agent; and/or
a water vapor feeding section for feeding water vapor to the nozzle;
wherein the nozzle includes a plasma generating section for generating the plasma, an outlet section for spraying the sterilizing agent, and a relaying section connected to the plasma generating section and the outlet section for feeding the plasma generated by the plasma generating section to the outlet section;
the water vapor feeding section is connected to the relaying section; and
the outlet section sprays , as the sterilizing agent, the plasma fed from the plasma generating section and ROS (Reactive Oxidizing Species) generated through a reaction between the plasma and the water vapor fed from the water vapor feeding section.

As ROS disappears (disintegrates) with lapse of time, there occurs no residual thereof. Further, sterilization using ROS does not require application of such heat that may cause thermal contraction in the sterilization object. Therefore, with the above-described configuration effecting sterilization with a sterilizing agent containing plasma and ROS, the above-described problems of residual of sterilizing agent and thermal contraction/deformation of the sterilization object can be avoided.

Further, the plasma generating section has a condition of high charge density in order to cause electric discharge required for the plasma generation. In case ROS is generated through a reaction between plasma and water vapor, it may seem that direct introduction of water vapor to the plasma generation section placed under the high charge density condition would achieve higher ROS generation efficiency. As a matter of fact, if a substance such as water vapor which has certain electro conductivity even though to a very low degree is introduced by an amount greater than a predetermined amount to the plasma generating section, this will result in deterioration in electric charge generation efficiency in the plasma generating section, thus making stable plasma generation impossible. For this reason, in the above-described configuration, water vapor is fed to a relaying section connected to the plasma generating section and the outlet section for feeding the plasma generated by the plasma generating section to the outlet section. With this arrangement, it is made possible to achieve stabilization of plasma generation while maintaining favorable ROS generation efficiency.

Next, the sterilizing device relating to this disclosure will be described by way of preferred embodiments thereof. It is understood, however, that the scope of the present disclosure is not to be limited to these preferred embodiments.

In one configuration, preferably, at least a portion of the relaying section downstream a portion thereof connected to the water vapor feeding section and at least a portion of the outlet section where the sterilizing agent is conducted are formed of non-metal substance.

Namely, in this disclosure, ROS is generated through a reaction between plasma and water vapor. And, this reaction occurs at a portion of the relaying section downstream a portion thereof connected to the water vapor feeding section and a portion of the outlet section where the sterilizing agent is conducted. Then, if these portions were formed of metal, as metal generally has higher heat conductivity than other substances (non-metal substances), heat of the water vapor when it passes these portions will be taken by the metal, whereby the water vapor will be condensed inadvertently. If this occurs, since such condensed water (mist) has lower reaction efficiency with plasma in comparison with water vapor (gas), deterioration of ROS generation efficiency will result. Consequently, the sterilization effect using ROS will be lower. On the other hand, with the above-described configuration, these portions are formed of a non-metal substance which generally has a lower heat conductivity than metals. Then, such reduction in the reaction efficiency with plasma will hardly occur. So that reduction of the sterilization effect using ROS can be inhibited advantageously.

In one configuration, preferably, the non-metal substance comprises resins having ozone resistance or ceramics.

After ROS is generated through the reaction between plasma and water vapor, this ROS include ozone. The ROS is caused to pass the portion of the relaying section downstream the portion thereof connected to the water vapor feeding section and the portion of the outlet section where the sterilizing agent is conducted. In this, in case these portions are formed of metal (e.g. Stainless) in particular, an oxidization reaction will occur between ROS and the metal, this will reduce the sterilization effect using the ROS and will also deteriorate this metal. On the other hand, with use of resins having ozone resistance or ceramics as a non-metal substance, there is obtained an advantage of such oxidization reaction will hardly occur. Then, since resins having ozone resistance or ceramics are used as the non-metal substance forming the above portions, the reduction in the sterilization effect and deterioration of the system which can occur with use of the sterilizing agent containing ROS are prevented

In one configuration, preferably, the outlet section includes an umbrella portion for covering a sterilization target face of the sterilization object at the time of its sterilization. As the sterilization target face of the sterilization object is covered by the umbrella portion at the time of sterilization, leakage of sterilizing agent containing plasma and ROS to the outside of the sterilization object can be restrained effectively. With this, the sterilization effect of the ROS can be effectively enhanced. Still preferably, the sterilization object is a cap to be attached to a bottle, and the umbrella portion covers an aperture face of the cap as the sterilization target face. In this case, leakage of the sterilizing agent containing plasma and ROS sprayed into the cap to the outside of the cap can be restrained effectively. With this, the sterilization effect of the ROS can be effectively enhanced.

In one configuration, preferably:
the umbrella portion includes a shielding face having an area greater than the sterilization target face of the sterilization object;
the shielding face defines a spray opening for spraying the sterilizing agent; and
at the time of sterilization, the outlet section sprays the sterilizing agent to the sterilization object, with the sterilization target face of the sterilization object and the shielding face being placed in opposition to each other and with the shielding face covering the sterilization target face. With the shielding face having an area greater than the sterilization target face of the sterilization object, this the sterilization target face of the sterilization object can be covered. And, since the sterilizing agent is sprayed to the sterilization object, with the sterilization target face of the sterilization object being covered by the shielding face. Therefore, leakage of the sterilizing agent to the outside of the sterilization object can be restrained even more effectively. With this, the sterilization effect of the ROS can be even more effectively enhanced. Still preferably, the sterilization object is a cap to be attached to a bottle, and the shielding face covers an aperture face of the cap as the sterilization target face. In this case, leakage of the sterilizing agent containing plasma and ROS sprayed into the cap to the outside of the cap can be restrained effectively. With this, the sterilization effect of the sterilizing agent using ROS can be effectively enhanced.

In one configuration, preferably, the shielding face defines a plurality of said spray openings in distribution. With this configuration, in comparison with a case of only one spray opening being defined in the shielding face, the spray openings defined in distribution allows effective dispersion or distribution of the sterilizing agent to the sterilization target face of the sterilization object. With this, the sterilization effect of the sterilizing agent using ROS can be even more effectively enhanced.

As described above, ROS disappears (disintegrates) with lapse of time. Then, in one configuration, preferably, the spray opening has a diameter which is smaller than an inside diameter of the relaying section. With this, the flow of sterilizing agent containing plasma and ROS fed from the relaying section is constricted, whereby the velocity of the flow of the sterilizing agent sprayed from the spray opening is increased. Accordingly, it becomes possible to effectively prevent occurrence of ROS disappearing before this ROS sterilizes the cap sufficiently. With this, the sterilization effect using ROS can be even more effectively enhanced.

In one configuration, preferably, the outlet section is formed like a pipe and includes a constricted portion having a diameter progressively reduced toward the spray opening provided at its leading end for spraying the sterilizing agent. With the above, the flow of sterilizing agent containing plasma and ROS is constricted, whereby the velocity of the flow of sterilizing agent sprayed from the spray opening is increased. Accordingly, it becomes possible to effectively prevent occurrence of ROS disappearing before this ROS sterilizes the cap sufficiently. With this, the sterilization effect using the sterilizing agent containing ROS can be even more effectively enhanced.

In one configuration, preferably the ROS contains hydroxy radical as its principal component. With presence of hydroxy radical which has a particularly high reactivity among various kinds of ROS, even higher sterilization effect can be achieved.

In one configuration, preferably, the sterilization object is a cap to be attached to a bottle.

Further and other technical advantageous effects and features of this disclosure will become apparent upon reading the following explanation of exemplary and non-limiting embodiments with reference to the accompanying drawings.

Fig. 1 is a schematic configuration diagram showing a sterilizing device for effecting ROS sterilization according to a first embodiment. Fig. 2 is a block diagram showing the sterilizing device for effecting ROS sterilization according to the first embodiment. Fig. 3 is an enlarged view showing a relaying section and an outlet section in the first embodiment. Fig. 4 is an enlarged view showing a relaying section and an outlet section in a second embodiment. Fig. 5 is an enlarged view showing a relaying section and an outlet section in a third embodiment. Fig. 6 is an enlarged view showing an outlet section in a fourth embodiment. Fig. 7 is an enlarged view showing a relaying section and an outlet section in a further embodiment.

First Embodiment
Next, a first embodiment of a sterilizing device relating to this disclosure will be explained with reference to the accompanying drawings. The sterilizing device 1 according to this embodiment sterilizes a cap 80 of a container such as a PET bottle as an example of a sterilization object. And, the device effects ROS sterilization with using, as a sterilizing agent therefor, reactive oxidizing species (ROS, e.g. OH radial, singlet oxygen, etc.) generated with using plasma. Then, a device configuration of the sterilizing device 1 for effecting the ROS sterilization will be explained.

Fig. 1 shows an ROS generating configuration or mechanism implemented by the sterilizing device 1. The sterilizing device 1 includes a nozzle 10 for generating ROS and spraying (irradiating) this ROS together with plasma as a sterilizing agent 70 to the sterilization object (cap) 80. This nozzle 10 includes a plasma generating section 11 for generating plasma, an outlet section 12 for spraying the sterilizing agent 70 containing plasma and ROS, and a relaying section 13 connected to the plasma generating section 11 and the outlet section 12.

This nozzle 10 is configured to generate so-called atmospheric pressure plasma as the plasma. The use of atmospheric pressure plasma allows device cost reduction since such component as a vacuum vessel required otherwise for low pressure plasma can be omitted, and allows also a continuous operation, thus achieving high operational efficiency. The use of atmospheric pressure plasma provides a further advantage that as this can be generated even at a low temperature, exposure of the sterilization object to high temperature can be avoided. Next, there will be explained generation of such atmospheric pressure plasma (to be referred to simply as “plasma” hereinafter) by the nozzle 10 and the ROS generation utilizing the plasma.

The plasma generating section 11 having a well-known configuration includes an internal electrode 11a and an external electrode 11b. With this plasma generating section 11 in operation, by applying a high voltage (e.g. an effective voltage of 20 kV at frequency of 14 kHz) between the internal electrode 11a and the external electrode 11b, an electric field is generated within this plasma generating section 11by an AC power source 20. And, gas together with air is introduced into the plasma generating section 11 to pass this gas through the generated electric field, whereby plasma is generated. The generated plasma is fed to the relaying section 13. In the instant embodiment, oxygen (O₂) is introduced as an example of the gas to the plasma generating section 11, so that this oxygen is plasmatized. This plasmatization results in generation of oxygen radical and ozone (O₃), which are then fed to the relaying section 13.

The relaying section 13 is connected to an evaporator (an example of “water vapor feeding unit” to be detailed later) 40 to receive also water vapor therefrom. With this, in the relaying section 13, there occurs a reaction between the plasma fed from the plasma generating section 11 (oxygen radical and ozone) and water vapor fed from the evaporator 40, thereby to generate ROS. In the instant embodiment, it is provided such that through the reaction between oxygen plasma (oxygen radical and ozone) and water vapor, there is mainly generated hydroxy radical (・OH) which has a particularly high reactivity among various kinds of ROS.

More particularly, in association with the reaction between water vapor and plasma, hydrogen radical (・H) and hydroxy radical are produced from H₂O according to the following formula (1).

H₂O → ・H +・OH...... (1)

Further, as the hydrogen radical reacts with ozone, there are produced hydroxy radical and oxygen (O₂) according to the following formula (2).

H + O₃ →・OH + O₂......(2) 　

Then, the above formula (1) and formula (2) can be integrated into a formula (3) as follows.

H₂O + O₃ → 2・OH + O₂.......(3) 　

Namely, through the reaction between oxygen plasma and water vapor, the reaction of the above formula (3) is caused, so that hydroxy radical (・OH) can be generated in an efficient manner. As a result, the ROS thus produced contains highly reactive hydroxy radical as its principal component. With presence of hydroxy radical as its principal component, high sterilization effect can be achieved. And, as this ROS thus produced together with any plasma unreacted with the water vapor is sprayed as a sterilizing agent 70 from the outlet section 12 onto the sterilization object 80, sterilization of this sterilization object 80 is effected.

Next, the device configuration of the sterilizing device 1 shown in Fig.2 for effecting the ROS sterilization will be explained. The sterilizing device 1 includes, in addition to the nozzle 10, a generator 21 and a transformer 22 which together constitute the AC power source 20, a gas feeding unit 30 for feeding various kinds of gas to the nozzle 10 and the evaporator 40, the evaporator 40 for feeding water vapor to the relaying section 13, a pump 50 for feeding liquid water to the evaporator 40, and a chiller 60 for feeding cooling water to the nozzle 10.

The generator 21 generates an alternating current. For instance, in this embodiment, there is employed such current having a frequency of 14 kHz, an effective voltage of 300 V and an effective current of 11A. Then, the voltage of the AC current provided by the generator 21 is boosted from 300 V to 20 kV by the transformer 22. With this, a high voltage of 20 kV is applied between the internal electrode 11a and the external electrode 11b of the plasma generating section 11.

The gas feeding unit 30 feeds oxygen (O₂) together with air to the nozzle 10. The gas feeding unit 30 also feeds air which is used for feeding water vapor generated by the evaporator 40 to the relaying section 13. The gas feeding unit 30 includes a control panel 31. By operating this control panel 31, feeding amounts of the various gas to respective destinations can be adjusted. In the instant embodiment, it is configured in particular such that with an operation of the control panel 31, air is fed by 6L/min and oxygen is fed by 3L/min to the nozzle 10 and also air is fed by 3 L/min to the evaporator 40.

The evaporator 40 is configured such that a heating coil (not shown) incorporated therein is heated to 300℃, and liquid water fed from the pump 50 is heated by this heating coil to generate water vapor. Then, the water vapor is mixed with the air fed from the gas feeding unit 30, and the water vapor together with the air are fed to the relaying section 13. Incidentally, in the instant embodiment, the pump 50 can be configured to feed water by 1.2 mL/min to the evaporator 40, for instance.

The chiller 60 is configured such that with supply of cooling water to the nozzle 10, this nozzle 10 heated with the application of the high voltage thereto is cooled (chilled).

With the above-described sterilizing device 1 in operation, oxygen fed together with air from the gas feeding unit 30 to the nozzle 10 is plasmatized by the plasma generating section 11 and the oxygen plasma thus generated is caused to react in the relaying section 13 with the water vapor fed together with air from the evaporator 40, whereby ROS containing hydroxy radical as its principal component is produced in a continuous manner. And, as the ROS produced continuously in the relaying section 13 and any plasma unreacted with the water vapor is sprayed as the sterilizing agent 70 continuously from the outlet section 12, continuous treatment of the sterilization object 80 is made possible. In the instant embodiment, the sterilizing agent 70 containing plasma and ROS is sprayed by a flow rate of 50000 mm/sec at a temperature ranging from 50 to 80℃ from the outlet section.

Sterilization using ROS provides the following advantages. In the case of using a sterilizing agent containing hydrogen peroxide, it is necessary to effect a post cleaning operation to ensure that no sterilizing agent will remain on the sterilization object. However, it is difficult to remove all sterilizing agent by cleaning so there is a risk of some sterilizing agent remaining on the sterilization object inadvertently. Moreover, the spraying operation of the sterilizing agent and the cleaning operation subsequent thereto are carried out mainly at a high temperature. Thus, if the sterilization object is made of a material that suffers thermal contraction, e.g. a resin material, various restrictions will be imposed on the sterilizing process if excessive thermal contraction or deformation is to be avoided. On the other hand, as ROS disappears (disintegrates) with lapse of time, there occurs no residual thereof. Further, sterilization using ROS does not require application of such heat that may cause thermal contraction in the sterilization object. Therefore, the above-described problems of residual of sterilizing agent and thermal contraction/deformation of the sterilization object can be avoided.

Next details of the configuration of the sterilizing device 1 relating to this embodiment will be explained. The sterilizing device 1 relating to this embodiment will be explained by way of an example thereof being applied to a so-called intermittent conveyance wherein a cap 80 conveyed by a conveyor or the like is stopped for a predetermined period under the sterilizing device 1 during which sterilization of the cap 80 is effected; then, the sterilized cap 80 is sent out and also a new cap 80 is brought in and stopped under the sterilizing device 1. Incidentally, the application of the sterilizing device 1 is not limited thereto.

In the sterilizing device 1 relating to this embodiment, the outlet section 12 of the nozzle 10 includes an umbrella portion 14 for covering an aperture face 81 of the cap 80 at the time of its sterilization in order to restrain leakage of the sterilizing agent 70 containing plasma and ROS to the outside of the cap 80. Specifically, in this embodiment, as shown in Fig. 3, the umbrella portion 14 includes a shielding face 14a having a greater area than the aperture face 81 of the cap 80. And, the shielding face 14a defines a spray opening 15 for spraying the sterilizing agent 70. More particularly, the umbrella portion 14 is provided in the form of a circular plate having a greater diameter than the diameter of the aperture face 81 and the spray opening 15 is defined at the center portion of the circular shielding face 14a.

At the time of sterilization of the cap 80, the cap 80 is stopped with the center of its aperture face 81 being in alignment with the center of the spray opening 15. With this, there is realized a state in which the aperture face 81 of the cap 80 stopped under the sterilizing device 1 is placed in opposition to the shielding face 14a and the shielding face 14a covers the aperture face 81 (see Fig. 3). And, under this state, the outlet section 12 sprays the sterilizing agent 70 to the gap 80. As the aperture face 81 of the cap 80 is covered by the umbrella portion 14 at the time of sterilization, leakage of the sterilizing agent 70 to the outside of the cap 80 is restrained.

As shown in Fig. 3, when the shielding face 14a covers the aperture face 81, an aperture edge 82 of the cap 80 and the shielding face 14a are under a non-contact state from each other. Therefore, the umbrella portion 14 will not interfere with the cap 80 at the time of loading/unloading of the cap, and there is no need for such a mechanism as a lifting mechanism for retracting the outlet section 12 or the nozzle 10 entirely, away from the cap 80 at the time of loading/unloading. As a result, the device configuration can be simplified and its cost also can be reduced. Incidentally, even under the state of the shielding face 14a covering the aperture face 81 without any contact between the aperture edge 82 and the shielding face 14a, leakage of the sterilizing agent 70 to the outside can still be restrained sufficiently. Alternatively, it is also possible to effect sterilization with keeping the aperture edge 82 and the shielding face 14a in contact with each other to seal the interior of the cap 80. With this, leakage of the sterilizing agent 70 to the outside can be restrained even more effectively. Incidentally, in this case, in order to avoid interference of the umbrella portion 14 with the cap 80 at the time of loading/unloading, a lifting mechanism or the like will be provided for retracting the outlet section 12 or the nozzle 10 entirely, so that at the time of sterilization, the outlet section 12 or the nozzle 10 may be lowered to place the aperture edge 82 and the shielding face 14a into contact with each other whereas the outlet section 12 or the nozzle 10 may be lifted up at the time of loading/unloading of the cap 80.

Further, with the sterilization with ROS, the problems of residual of sterilizing agent and thermal contraction/deformation of the sterilization object can be avoided. However, if metal is used at portions where ROS is generated, as metal generally has higher heat conductivity than other substances (non-metal substances), heat of the water vapor when it passes these portions will be taken by the metal, whereby the water vapor will be condensed inadvertently. If this occurs, since such condensed water (mist) has lower reaction efficiency with plasma in comparison with water vapor (gas), deterioration of ROS generation efficiency will result. Consequently, the sterilization effect using ROS will be lower. Further, this ROS includes ozone and causes an oxidization reaction with a metal, if a portion where ROS is conducted is formed of a metal, this will reduce the sterilization effect using ROS and will also deteriorate this metal. For this reason, firstly, in order to restrict occurrence of the problem due to condensation of water vapor, preferably, the portion where ROS is generated is formed of a non-metal substance which generally has lower heat conductivity than metals. Still preferably, if the non-metal substance is a resin having ozone resistance or ceramics, the oxidization reaction that occurs with metals will occur even less likely. For this reason, it is preferred that a portion of the sterilizing device 1 where ROS is conduced be formed of a resin having ozone resistance or ceramics. ROS is generated at a connecting portion between the relaying section 13 and the evaporator 40 and at a portion downstream thereof, where the reaction between plasma and water vapor occurs. Therefore, in the sterilizing device 1, the ROS conducting/generating portion is located at a portion of the relaying section 13 downstream a portion thereof connected to the evaporator 40. According, preferably, at least a portion of the relaying section 13 downstream a portion thereof connected to the evaporator 40 and at least a portion of the outlet section 12 where the sterilizing agent 70 containing plasma and ROS is conducted are formed of resins having ozone resistance or ceramics. Then, in one configuration, in the sterilizing device 1 relating to this embodiment, the outlet section 12 (including the umbrella portion 14) entirely and the relaying section 13 also entirely are formed of resin. This arrangement prevents the sterilization effect reduction and the system deterioration that could occur with the use of ROS.

Here, Table 1 below shows sterilization effect indices: LRV (Logarithmic Reduction Value) per unit irradiating ( spraying) period between the case of the outlet section 12 and the relaying section 13 being formed of resin and the case of these being formed of metal, in comparison with each other. In this case, PP (Polypropylene) is employed as resin and stainless steel is employed as metal, respectively. As may be apparent from Table 1, LRV shows higher values for the resin, so it is understood that forming the outlet section 12 and the relaying section 13 of resin achieves higher sterilizing effect that forming them of metal.

The resin employed for forming the outlet section 12 and the relaying section 13 is not particularly limited to PP described above. Instead, resins having ozone resistance such as PEEK (polyether ketone), fluorocarbon polymers can also be employed.

Second Embodiment
Next, a second embodiment of the sterilizing device relating to this disclosure will be explained with reference to Fig. 4. In this embodiment, the configurations of the outlet section 12 and the relaying section 13 differ from those of the first embodiment. Next, regarding the sterilizing device relating to this embodiment, differences from the first embodiment will mainly be explained. Incidentally, as for those respects not explicitly described, such respects are understood to be identical to those of the first embodiment. And, they are provided with same or similar reference marks and detailed discussion thereof will be omitted.

In this embodiment, unlike the first embodiment in which the entire outlet section 12 and the entire relaying section 13 are formed of resins having ozone resistance or ceramics, there is shown a configuration wherein at least a portion of the relaying section 13 downstream a portion thereof connected to the evaporator 40 and at least a portion of the outlet section 12 where the sterilizing agent 70 containing ROS is conducted are formed of resins having ozone resistance or ceramics. As shown in Fig. 4, the outlet section 12 and the relaying section 13 are comprised of a portion 13A upstream of the connecting portion 13a and including this connecting portion 13a and an attachment 16 detachably attachable to this upstream portion 13A. The attachment 16 consists of a portion 13B downstream of the connecting portion 13a as the relaying portion 13 and the outlet section 12 connected thereto. And, the upstream portion 13A is formed of a material such a metal different from the resins or ceramics, whereas the attachment 16 is formed of the resins having ozone resistance or ceramics. With this, as least the ROS conducting portion is formed of resins having ozone resistance or ceramics, so that the above-described sterilization effect reduction and the system deterioration can be prevented. Moreover, since the attachment 16 entirely is formed of resins having ozone resistance or ceramics, the shielding face 14a to which ROS comes into contact when this shielding face 14a of the umbrella portion 14 covers the aperture face 81 of the cap 80 at the time of sterilization is formed of the resins having ozone resistance or ceramics as well.

Third Embodiment
Next, a third embodiment of the sterilizing device relating to this disclosure will be explained with reference to Fig. 5. In this embodiment, the configuration of the outlet section 12 differs from that of the first embodiment. Next, regarding the sterilizing device relating to this embodiment, differences from the first embodiment will mainly be explained. Incidentally, as for those respects not explicitly described, such respects are understood to be identical to those of the first embodiment. And, they are provided with same or similar reference marks and detailed discussion thereof will be omitted.

In this embodiment, as shown in Fig. 5, the outlet section 12 is configured such that its conduit for the sterilizing agent 70 has a diameter which progressively increases toward the shielding face 14a and this diameter when reaching the shielding face 14a becomes substantially equal to the aperture diameter of the cap 80. And, in the shielding face 14a, unlike the first embodiment, there are defined a plurality of spray opening 15 in distribution. These spray openings defined in distribution allows effective dispersion or distribution of the sterilizing agent inside the cap. Further, the diameter of each spray opening 15 is smaller than the inside diameter of the relaying section 13. With this, as the diameter of the conduit for the sterilizing agent 70 is progressively increased toward the shielding face 14a, this causes also widening of the flow of the sterilizing agent 70 through each spray opening 15, but since the flow of the sterilizing agent 70 is constricted by each spray opening 15, the velocity of the flow of the sterilizing agent 70 from the spray opening 15 is increased. Therefore, it is possible to restrict occurrence of the phenomenon of ROS disappearing with lapse of time being lost (disappearing) before being able to sterilize the cap 80 sufficiently.

Incidentally, in this embodiment too, like the second embodiment, the outlet section 12 and the relaying section 13 can be comprised of the portion 13A upstream of the connecting portion 13a and including this connecting portion 13a and the attachment 16 detachably attachable to this upstream portion 13A.

Fourth Embodiment
Next, a fourth embodiment of the sterilizing device relating to this disclosure will be explained with reference to Fig. 6. In this embodiment, the configuration of the outlet section 12 differs from those of the first through third embodiments. Next, regarding the sterilizing device relating to this embodiment, differences from the first embodiment will mainly be explained. Incidentally, as for those respects not explicitly described, such respects are understood to be identical to those of the first embodiment. And, they are provided with same or similar reference marks and detailed discussion thereof will be omitted.

Fig. 6 shows an outlet section 12 according to this embodiment. This outlet section 12 is formed like a pipe and includes a constricted portion 17 having a diameter progressively reduced toward the spray opening 15 provided at its leading end for spraying the sterilizing agent 70. Since the flow of the sterilizing agent 70 is constricted by the spray opening 15, the velocity of the flow of the sterilizing agent 70 sprayed from the spray opening 15 is increased. Accordingly, it becomes possible to effectively prevent occurrence of ROS disappearing before this ROS sterilizes the cap 80 sufficiently.

Other Embodiments
Lastly, other embodiments of the sterilizing device relating to this disclosure will be explained. In the first and second embodiments, there was shown the configuration in which the umbrella portion 14 is provided in the form of a circulate plate. The embodiment of this disclosure is not limited thereto. For instance, as shown in Fig. 7, the umbrella portion 14 can be formed like a box which is open downwardly. At the time of sterilization, the cap 80 will be accommodated inside the box, thereby to cover the aperture opening 81 of the cap 80. Further alternatively, the umbrella portion can be provided in any other shape such as a conical shape, a regular prism shape and, like the first and second embodiments, a shielding face 14a having a greater area than the aperture face 81 of the cap 80 may be provided on the side opposed to the aperture face 81 of the cap 80. Further, the shape of the shielding face 14a is not limited to the circular shape, but can be any polygonal shape such as a quadrilateral shape, as long as it has a greater area than the aperture face 81 of the cap 80. In the foregoing embodiment, a cap to be attached to a bottle was used as an example of the sterilization object. However, this disclosure is not limited thereto. Any other object can also be used as the sterilization object. In such case, preferably, the umbrella portion 14 will be configured to cover a sterilization target face of such sterilization object.

Further, in the foregoing embodiment, there was disclosed the arrangement wherein the portion of the relaying section 13 downstream its portion connected to the evaporator 40 and the portion of the outlet section 12 where the sterilizing agent is conducted are formed of resins having ozone resistance or ceramics. However, the present disclosure is not limited thereto. The above portions can be formed of any other non-metal substance than resins having ozone resistance, ceramics or can also be formed of metal.

As for the other configurations too, the embodiments disclosed in this disclosure are understood to be exemplary in all respects, and it is understood that the scope of this disclosure is not to be limited thereto. Those skilled in the art will easily understand that various modifications will be possible within a range not deviating from the essential concept of this disclosure. And, it is understood that other embodiments or modifications modified in such range not deviated from the essential concept too will be encompassed within the scope of this disclosure, as a matter of course.

This disclosure is applicable to a sterilizing device for sterilizing a sterilization object such as a cap.

1 sterilizing device
10 nozzle
11 plasma generating section
12 outlet section
13 relaying section
13a connected portion
14 umbrella portion
14a shielding face
15 spray opening
17 constricted portion
40 evaporator (water vapor feeding section)
70 sterilizing agent
80 cap (sterilization object)
81 aperture face (sterilization target face)

Claims

A sterilizing device, the device sterilizing a sterilization object by generating plasma and irradiating the generated plasma to the object, the sterilizing device comprising:
a nozzle for spraying sterilizing agent; and/or
a water vapor feeding section for feeding water vapor to the nozzle;
wherein the nozzle includes a plasma generating section for generating the plasma, an outlet section for spraying the sterilizing agent, and a relaying section connected to the plasma generating section and the outlet section for feeding the plasma generated by the plasma generating section to the outlet section;
the water vapor feeding section is connected to the relaying section; and
the outlet section sprays, as the sterilizing agent, the plasma fed from the plasma generating section and ROS (Reactive Oxidizing Species) generated through a reaction between the plasma and the water vapor fed from the water vapor feeding section.
The sterilizing device according to claim 1, wherein at least a portion of the relaying section downstream a portion thereof connected to the water vapor feeding section and at least a portion of the outlet section where the sterilizing agent is conducted are formed of non-metal substance.
The sterilizing device according to claim 2, wherein the non-metal substance comprises resins having ozone resistance or ceramics.
The sterilizing device according to any one of claims 1-3, wherein the outlet section includes an umbrella portion for covering a sterilization target face of the sterilization object at the time of its sterilization.
The sterilizing device according to claim 4, wherein:
the umbrella portion includes a shielding face having an area greater than the sterilization target face of the sterilization object;
the shielding face defines a spray opening for spraying the sterilizing agent; and
at the time of sterilization, the outlet section sprays the sterilizing agent to the sterilization object, with the sterilization target face of the sterilization object and the shielding face being placed in opposition to each other and with the shielding face covering the sterilization target face.
The sterilizing device according to claim 5, wherein the shielding face defines a plurality of said spray openings in distribution.
The sterilizing device according to claim 5 or 6, wherein
the spray opening has a diameter which is smaller than an inside diameter of the relaying section.
The sterilizing device according to claim 1, wherein the outlet section is formed like a pipe and includes a constricted portion having a diameter progressively reduced toward the spray opening provided at its leading end for spraying the sterilizing agent.
The sterilizing device according to any one of claims 1-8, wherein the ROS contains hydroxy radical as its principal component.
The sterilizing device according to any one of claims 1-9, wherein the sterilization object is a cap to be attached to a bottle.