Sterilizing device

Abstract

To provide a sterilizer that is capable of dealing with articles with different processing capacities while suppressing radiation output of electron ray, ultraviolet ray or the like.SOLUTION: A sterilizer 10 comprises: a first intermediate wheel 24 and a conveyance wheel 26 which hold and convey articles M by grippers; a sterilization chamber 12 housing the wheels 24, 26; a radiation irradiation unit 18 having an irradiation window 18A through which articles are irradiated with radiation; and a first pitch changing wheel 22 which is provided for an upstream side of the first intermediate wheel 24, and changes a conveyance interval of the articles M to be passed to the first intermediate wheel 24. In a first sterilization mode, the articles M are supplied to the first intermediate wheel 24 by the first pitch changing wheel 22 at an interval of an integral multiple of an interval of grippers of the first intermediate wheel 24 and perform sterilization. In a second sterilization mode, the articles M are supplied to the first intermediate wheel 24 by the first pitch changing wheel 22 at an interval equal to the interval of grippers of the first intermediate wheel 24 and perform sterilization.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a sterilization device that irradiates articles to be conveyed with radiation such as electron beams and ultraviolet rays for sterilization.

Background Art

[0002] In an electron beam sterilization device as an example of a sterilization device, articles continuously conveyed in a sterilization chamber are irradiated with electron beams to sterilize the articles. For conveying the articles, for example, a conveying wheel provided with grippers at a predetermined pitch along the outer circumference is used. The articles gripped and conveyed by the grippers are irradiated with electron beams through the irradiation window of the electron beam irradiation unit. That is, while the articles are moved by the conveying wheel to a predetermined area (irradiation area) facing the irradiation window, the articles are exposed to the electron beams and sterilized (Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As a line where an electron beam sterilization device is used, for example, a filling line for containers such as PET bottles can be mentioned. In such a filling line, the production capacity (supply amount) varies depending on the size of the articles due to differences in filling capacity and the like. For example, the production capacity per unit time of small-capacity containers is higher than that of large-capacity containers. Therefore, when an electron beam sterilization device is also used in a line that handles articles with different processing capabilities depending on the type, it is necessary to change the conveying speed by the wheel according to the type of the articles. On the other hand, the absorbed dose of the articles in the electron beam sterilization device changes depending on the electron beam output and the residence time of the articles in the irradiation area.

[0005] For example, when the sterilization device is used in both Mode A for processing a 500 ml container at a processing speed of 600 bpm and Mode B for processing a 2 L container at a processing speed of 300 bpm, the gripper interval of the conveying means in the conventional sterilization device is set at an interval suitable for the large-sized container so that adjacent containers do not interfere with each other. Therefore, the gripper interval of the conveying means is set at an interval suitable for Mode B (for example, a 200 mm pitch). When the irradiation area of the electron beam is 1 m, the time that a container stays in the irradiation area per container is about 2 seconds. On the other hand, in the case of Mode A, since the conveying speed is twice that of Mode B, the time that a container stays in the irradiation area per container is about 1 second. Therefore, in order to maintain an appropriate absorption dose in Mode A, it is necessary to increase the electron beam output in Mode A.

[0006] Therefore, in a filling line where small-diameter containers and large-diameter containers with high processing capabilities are sterilized by the same sterilization device, there is a problem that it is necessary to increase the electron beam output for small containers, resulting in an increase in running costs.

[0007] An object of the present invention is to provide a sterilization device capable of coping with articles having different processing capabilities while suppressing the output of radiation such as electron beams and ultraviolet rays.

Means for Solving the Problem

[0008] The sterilization device of the present invention includes an article conveying means for holding and conveying an article by an article holding portion, a sterilization chamber housing the article conveying means, and radiation for held by the article conveying means A sterilization device comprising a radiation irradiation unit having an irradiation window for irradiating an article oh In the sterilization device, an interval changing conveyance means is provided upstream of the article conveyance means for changing the conveyance interval of the article delivered to the article conveyance means, and kill Control means for controlling the operation of the sterilization device, and the control means conveys an article to the article conveyance means at an interval that is an integer multiple of the interval between the article holding portions by the interval changing conveyance means supply In a first sterilization mode for sterilizing an article, and an article is conveyed to the article conveyance means at an interval equal to the interval between the article holding portions by the interval changing conveyance means supplyIt is characterized in that the operation mode can be switched between the second sterilization mode for sterilizing the article.

Effect of the Invention

[0009] According to the present invention, it is possible to provide a sterilization apparatus capable of dealing with articles having different processing capabilities while suppressing radiation output such as electron beams and ultraviolet rays.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Mode for Carrying Out the Invention

[0011] Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a plan view showing the arrangement of the sterilization apparatus which is one embodiment of the present invention.

[0012] The sterilization apparatus of the present embodiment is, for example, an electron beam sterilization apparatus 10. The electron beam sterilization apparatus 10 is used in common for articles M having different quantities (processing capabilities) supplied per unit time. The article M is, for example, a container in which processes such as filling and blow molding are performed upstream of the electron beam sterilization apparatus 10, and the electron beam sterilization apparatus 10 is used in common for containers having different capacities. The electron beam sterilization apparatus 10 includes a sterilization chamber 12, and the article M is supplied from the carry-in chamber 14 into the sterilization chamber 12, and after the sterilization treatment in the sterilization chamber 12 is completed, it is discharged from the discharge chamber 16.

[0013] An electron beam irradiation unit 18 is disposed adjacent to the sterilization chamber 12. An opening 12A for irradiating the electron beam from the irradiation window 18A into the sterilization chamber 12 is provided at a position on the side surface of the sterilization chamber 12 corresponding to the irradiation window 18A of the electron beam irradiation unit 18. Note that the output of the electron beam irradiation unit 18 can be controlled by the control device 20.

[0014] In the sterilization chamber 12, a plurality of rotating wheels provided with a plurality of grippers (article holding portions) along the outer periphery are arranged. The article M is transferred between the grippers of each rotating wheel and conveyed in the sterilization chamber 12. In the sterilization chamber 12 of the present embodiment, a first pitch change wheel (spacing change means) 22, a first intermediate wheel (article conveying means) 24, a conveying wheel (article conveying means) 26, a second intermediate wheel 28, and a second pitch change wheel (spacing change means) 30 are arranged in this order from the upstream side.

[0015] Note that the article M is supplied from the introduction wheel 14A in the carry-in chamber 14 to the first pitch change wheel 22, and the article M held by the second pitch change wheel 30 is discharged from the sterilization chamber 12 via the discharge wheel 16A in the discharge chamber 16. Further, in the electron beam sterilizer 10, the first pitch change wheel 22, the first intermediate wheel 24, the conveying wheel 26, the second intermediate wheel 28, and the second pitch change wheel 30 are rotated synchronously, and the rotation is controlled by the control device 20.

[0016] The conveying wheel 26 is disposed adjacent to the opening 12A so that the gripper passes through a region (irradiation region) in the sterilization chamber 12 irradiated with the electron beam. That is, the article M conveyed by the conveying wheel 26 passes through the irradiation region in a part of the conveying path and is sterilized by being exposed to the electron beam during the transfer in the region.

[0017] In this embodiment, the interval (conveying pitch) P1 between the grippers of the conveying wheel 26 and the first and second intermediate wheels 24 and 28 is fixed at the same value. These conveying pitches are set to an interval corresponding to the article M with the highest supply rate (highest processing capacity) among the articles M processed in the electron beam sterilization apparatus 10. Further, the interval (conveying pitch) P2 of the gripper is used for conveying small containers in this embodiment and is set to, for example, twice the conveying pitch P1. On the other hand, the interval (conveying pitch) P3 of the grippers of the wheels upstream of the first pitch change wheel 22 such as the introduction wheel 14A and the wheels downstream of the second pitch change wheel 30 such as the discharge wheel 16A is appropriately set according to the processing apparatuses of the upstream apparatus and the downstream apparatus.

[0018] The first and second pitch change wheels 22 and 30 have substantially the same configuration. As will be described later with reference to FIG. 2, the interval (conveying pitch) P between the grippers 32 of the first and second pitch change wheels 22 and 30 can be set to the interval P1 or P2 in the article M transfer section A with the first and second intermediate wheels 24 and 28, and is set to the interval P3 in the article M transfer section B with the introduction wheel 14A and the discharge wheel 16A. In the first pitch change wheel 22 of this embodiment, the interval P of the gripper 32 can be switched to P1 or P2 only in the article M transfer section A with the first intermediate wheel 24, and is set to P3 in other sections including the transfer section B. Note that the interval (conveying pitch) of the gripper 32 in the transfer section A is selected according to the processing capacity of the article to be processed.

[0019] FIG. 2 is a plan view showing the arrangement of a part of the introduction wheel 14A and the first intermediate wheel 24 around the first pitch change wheel 22. As shown in FIG. 2, the grippers 14G and 24G of the introduction wheel 14A and the first intermediate wheel 24 are opened and closed by the engagement of cam followers 14F and 24F at the tips of levers provided on the rotation axes of the grippers with cams 14C and 24C, respectively. Further, the gripper 32 of the first pitch change wheel 22 is a gripper that has no opening and closing mechanism and holds an article M (for example, the neck of a PET bottle) by pushing it into a pair of grip members attracted by a spring or the like. Thus, in the conveyance paths other than the sections A and B, the grippers 14G, 32, and 24G grip the article M, and the article M is delivered in the sections A and B. Note that the opening and closing of the grippers of the conveyance wheel 26, the second intermediate wheel 28, the second pitch change wheel 30, and the discharge wheel 16A are also performed by the same mechanism, and thus the description thereof is omitted.

[0020] The cam 34 of the first (second) pitch change wheel 22 (30) includes a plurality of first movable cams 34A and second cams 34B in the section A. The first and second movable cams 34A and 34B can move forward and backward in the radial direction by a forward and backward mechanism 36 using an air cylinder or the like, and when one is pushed out to the outside and functions as a cam, the other is retracted to the standby position. That is, the direction of the gripper 32 and the swing of the cam follower 32F are controlled by a common cam 34 outside the section A, and are controlled by either the first movable cam 34A or the second movable cam 34B in the section A.

[0021] In the sections other than the section A, the gripper 32 is always moved at an interval P3, and is conveyed while maintaining the interval P3 in the section B. In the section A, when the first movable cam 34A is pushed out, the gripper 32 is conveyed with the interval changed to P2 in the section A. On the other hand, when the second movable cam 34B is pushed out, the gripper 32 is conveyed with the interval changed to P1 in the section A. In FIG. 2, the forward and backward mechanism 36 of the first movable cam 34A is arranged below the forward and backward mechanism 36 of the second movable cam 34B, and the drive of each forward and backward mechanism 36 is controlled by, for example, a control device 20.

[0022] Next, with reference to FIGS. 3 and 4, the conveyance operations in the first sterilization mode for sterilizing the large-capacity article M1 and the conveyance operations in the second sterilization mode for sterilizing the small-capacity article M2 will be described. In the present embodiment, the article M1 is a large container and the article M2 is a small container.

[0023] As shown in FIG. 3, when performing the sterilization process of the article M1, the electron beam sterilizer 10 is set to the first sterilization mode. In the first sterilization mode, the first movable cam 34A is selected (pushed out), and the article M1 is conveyed at a conveyance pitch P2 by the wheels 24, 26, and 28. The wheels 22, 24, 26, 28, and 30 are each rotated synchronously at a rotation speed corresponding to the article M1, and the electron beam irradiation unit 18 irradiates the article M1 with an electron beam at an intensity corresponding to the article M1. In the first sterilization mode, in the first and second intermediate wheels 24 and 28 and the conveyance wheel 26, the article M1 is conveyed at the conveyance pitch P2 by the grippers gripping the article M1 every other one.

[0024] On the other hand, as shown in FIG. 4, when performing the sterilization process of the article M2, the electron beam sterilizer 10 is set to the second sterilization mode. In the second sterilization mode, the second movable cam 34B is selected (pushed out), and the first pitch change wheel 22 receives the article M2 from the introduction wheel 14A at the conveyance pitch P3, converts the conveyance pitch from P3 to P1, and then delivers it to the first intermediate wheel 24. Also, in the second pitch change wheel 30, the article M1 is received from the second intermediate wheel 28 at the conveyance pitch P1, converted to the conveyance pitch P3, and then delivered to the discharge wheel 16A. The wheels 22, 24, 26, 28, and 30 are each rotated synchronously at a rotation speed corresponding to the article M2, and the electron beam irradiation unit 18 irradiates the article M2 with an electron beam at an intensity corresponding to the article M2. In the first and second intermediate wheels 24 and 28 and the conveyance wheel 26, all the grippers grip the article M2, and the article M2 is conveyed at the conveyance pitch P1.

[0025] As described above, in this embodiment, in the article sterilization apparatus, by making it possible to change the conveyance pitch according to the processing capacity of the article (the amount of article supply per unit time), when handling an article with a high processing capacity, by reducing the conveyance pitch, it is possible to suppress an increase in the conveyance speed and a shortening of the passing time of the article through the electron beam irradiation region. That is, even for an article with a high processing capacity, it becomes possible to set a longer time for moving through the irradiation region. As a result, even when articles are supplied with a high processing capacity, it is possible to suppress the electron beam output and perform sufficient sterilization processing on the articles.

[0026] In the first and second pitch change wheels of this embodiment, the interval between the grippers (conveyance pitch) could be changed between P1 and P2 which is twice that of P1, but it may also be made convertible to intervals that are integer multiples of three times or more. In that case, the selection of the interval can be made using three or more movable cams. Also, in this embodiment, the wheel conveyance using grippers has been described as an example, but the holding mechanism and conveyance form of the article are not limited to this embodiment. Further, the radiation used for sterilization is not limited to electron beams, and may be non-ionizing radiation such as ultraviolet rays, electromagnetic waves such as γ-rays, or other particle beams.

Explanation of Reference Numerals

[0027] 10 Electron beam sterilization apparatus (sterilization apparatus) 12 Sterilization chamber 12A Opening 18 Electron beam irradiation unit (radiation irradiation unit) 18A Irradiation window 20 Control device (control means) 22 First pitch change wheel (interval change means) 24 First intermediate wheel (article conveyance means) 24G Gripper (article holding part) 26 Conveyance wheel (article conveyance means)

Claims

【Claim 1】 A sterilization apparatus comprising: article conveying means for holding and conveying an article by an article holding portion; a sterilization chamber housing the article conveying means; and a radiation irradiation unit having an irradiation window for irradiating the article held by the article conveying means with radiation, spacing change conveying means provided upstream of the article conveying means for changing the conveying spacing of the articles delivered to the article conveying means, control means for controlling the operation of the sterilization apparatus, wherein the control means, is capable of switching between a first sterilization mode in which articles are supplied to the article conveying means at intervals that are an integral multiple of the spacing between the article holding portions by the spacing change conveying means to sterilize the articles, and a second sterilization mode in which articles are supplied to the article conveying means at a spacing equal to the spacing between the article holding portions by the spacing change conveying means to sterilize the articles A sterilization apparatus characterized by the above.

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