JP2018503565A - Electron beam sterilization system having an external sterilization emitter that moves relative to the object to be sterilized - Google Patents

Abstract

An object of the present invention is to efficiently sterilize the outer surface of an object to be sterilized such as a beverage, food, or pharmaceutical container. An electron beam sterilization system according to the present invention is an electron beam sterilization system that sterilizes an object to be sterilized (C) while being conveyed along a conveyance path (R), and is provided on the outer surface of the object to be sterilized (C). When sterilizing the outer surface of the sterilization object (C) by irradiating with an electron beam, the sterilization object (C) and the outer surface sterilization emitter are different in a direction different from the direction along the conveyance path (R). And a relative movement device for relatively moving the two.

Description

  The present invention relates to a sterilization system for sterilizing an object to be sterilized such as a container used for packaging foods, beverages, and pharmaceuticals.

  Here, sterilization refers to a method of sterilization, sterilization, or sterilization. In food, beverage and drug packaging, sterilization is performed to destroy pathogens to prolong the shelf life of the product and to distribute the product safely and easily. For this reason, safe sterilization is required for beverage and food containers and pharmaceutical containers.

  Recently, sterilization methods using an electron beam have been markedly advantageous over other sterilization methods. A sterilization method using an electron beam emitter capable of irradiating an electron beam is quick and reliable. Further, in the sterilization method using chemicals, the chemicals after use have an adverse effect on the environment, so that treatment of waste liquid and exhaust is necessary, which is difficult and expensive. Furthermore, since an electron beam sterilization system comprising such an electron beam emitter does not use chemicals, no chemicals remain in the sterilized container, and thus a high level of consumer safety is achieved.

  As an electron beam sterilization system for sterilizing containers such as beverages, foods, and pharmaceuticals, there are those described in Patent Documents 1 and 2, for example. As shown in FIGS. 14 to 16, the electron beam sterilization system 5 described in Patent Documents 1 and 2 includes a first outer surface sterilization emitter E3, a second outer surface sterilization emitter E4, an inner surface sterilization emitter having a nozzle 24a, and a transport device. M0 to M3 and a radiation shield S are provided. 14 indicates the nozzle 24a of the inner surface sterilization emitter. In FIG. 16, the inner surface sterilization emitter is shown only in the portion of the nozzle 24a, and the other portions are omitted.

  As shown in FIG. 14, the transport devices M <b> 0 to M <b> 3 have a holding arm A, and continuously transport the containers C along the transport path R while the holding arms A hold the containers C. As shown in FIG. 15, the outer surface sterilization emitters E3 and E4 are flat emitters that can irradiate an electron beam over a wide range, and in a state where the holding arms A of the transfer devices M0 to M3 hold the container C, Sterilize by irradiating the outer surface of C with an electron beam. The first outer surface sterilization emitter E3 sterilizes half of the entire outer surface of the container C, and the second outer surface sterilization emitter E4 sterilizes the remaining half of the entire outer surface of the container C. As shown in FIG. 16, the inner surface sterilization emitter sterilizes the inner surface of the container C with an electron beam irradiated from the nozzle 24a in a state where the nozzle 24a is inserted into the container C.

JP 2011-201600 A International Publication No. 2014/095842

However, in the conventional electron beam sterilization system 5, the entire outer surface of the container C is sterilized by the fixed outer surface sterilization emitters E3 and E4. That is, when the outer surface of the container C is sterilized, the sterilization target C and the outer surface sterilization emitters E3 and E4 move relatively only in the direction in which the container C is transported. Therefore, the distance between the container C and the outer surface sterilization emitters E3 and E4 is different for each part of the container C.
For example, when the container C has a neck and a body, the neck of the container C has a large distance from the outer surface sterilization emitters E3 and E4, whereas the body of the container C has a distance from the outer surface sterilization emitters E3 and E4. small. In order to reliably sterilize a neck having a large distance, the irradiation intensity of the outer surface sterilization emitters E3 and E4 may be increased or the conveyance speed of the container C may be decreased. As a result, the sterilization of the outer surface of the container C becomes non-uniform.
An object of this invention is to equalize | sterilize the outer surface of sterilization objects, such as a container.

  An electron beam sterilization system of the present invention solves the above-described problem, and is an electron beam sterilization system that sterilizes an object to be sterilized while being conveyed along a conveyance path, and irradiates an outer surface of the object to be sterilized with an electron beam. Relative movement device for relatively moving the sterilization object and the external sterilization emitter in a direction different from the direction of conveyance along the conveyance path when sterilizing the external surface of the sterilization object and sterilizing the external surface of the sterilization object It is characterized by providing.

  According to the electron beam sterilization system of the present invention, the entire outer surface of the object to be sterilized is sterilized by the outer surface sterilization emitter that is movable relative to the object to be sterilized. Therefore, it is possible to control the irradiation intensity and the conveyance speed of the outer surface sterilization emitter according to the relative position between the sterilization target and the outer surface sterilization emitter. Thereby, uniform sterilization is possible for the entire outer surface of the object to be sterilized.

It is a top view of the electron beam sterilization system concerning an embodiment of the invention.

It is a figure explaining the structure and operation | movement of an outer surface sterilization emitter and an inner surface sterilization emitter of the same electron beam sterilization system.

It is a figure which shows a part of same electron beam sterilization system, Comprising: It is B-BB sectional drawing in FIG.

It is the cross-sectional schematic of the outer surface sterilization emitter and inner surface sterilization emitter of the same electron beam sterilization system.

It is a figure explaining the structure and operation | movement of the other aspect of the outer surface sterilization emitter of this invention, and an inner surface sterilization emitter.

It is a figure explaining the structure and operation | movement of the other aspect of the outer surface sterilization emitter of this invention, and an inner surface sterilization emitter.

It is a figure explaining the structure and operation | movement of the other aspect of the outer surface sterilization emitter of this invention, and an inner surface sterilization emitter.

It is a figure which shows the other aspect of the nozzle of the external surface sterilization emitter of this invention.

It is a figure explaining a mode that an electron beam is irradiated from a window part in the outer surface sterilization emitter shown by FIG. 8A.

It is a figure which shows the other aspect of the nozzle of the external surface sterilization emitter of this invention.

It is a figure explaining a mode that an electron beam is irradiated from a window part in the outer surface sterilization emitter shown by FIG. 9A.

It is a figure which shows the relative dose with respect to the sterilization target object of the electron beam emitter, and the distance of the window part and sterilization target object in the different irradiation intensity | strength of an electron beam emitter.

It is the plane schematic which shows the other aspect of the electron beam sterilization system of this invention.

It is the plane schematic which shows the other aspect of the electron beam sterilization system of this invention.

It is the plane schematic which shows the other aspect of the electron beam sterilization system of this invention.

It is a top view of the conventional electron beam sterilization system.

It is a figure explaining the outer surface sterilization emitter of the conventional electron beam sterilization system.

It is a figure explaining the inner surface sterilization emitter of the conventional electron beam sterilization system.

[Embodiment 1]
First, an electron beam sterilization system and an electron beam sterilization method according to Embodiment 1 of the present invention will be described with reference to the drawings. 1 to 4, an electron beam sterilization system 1 according to Embodiment 1 of the present invention includes an outer surface sterilization emitter E1 (see FIG. 4) having a nozzle 14a and an inner surface sterilization emitter E2 (see FIG. 4). 3 and 4), a radiation shield S (see FIG. 1), and first to third transfer devices M1 to M3 (see FIG. 1). 1 indicate the outer surface sterilization emitter nozzle 14a or the inner surface sterilization emitter nozzle 24a. 1 and 2, only the nozzle portion of the outer surface sterilization emitter and the inner surface sterilization emitter is shown, and the other portions are omitted.

  The outer surface sterilization emitter E1 is a device that sterilizes by irradiating the outer surface of the sterilization target C with an electron beam. The inner surface sterilization emitter E2 is a device for sterilization by irradiating the inner surface of the sterilization target C with an electron beam. The sterilization target C is, for example, a container for packaging beverages, foods, and pharmaceuticals, a preform thereof, and the like. The first to third transport devices M1 to M3 transport the sterilization target C while holding it. Specifically, as shown in FIG. 1, the transfer devices M1 to M3 include circular first to third turning tables T1 to T3 and a holding arm A connected to the outer periphery of the turning tables T1 to T3. Have. In a state where the holding arm A holds and holds the neck of the sterilization target C, the sterilization target C is transported by turning the turning tables T1 to T3.

  An arrow R in FIG. 1 indicates a conveyance path of the sterilization target C. As shown in the conveyance path R, when the holding arms A connected to different turning tables T1 to T3 approach each other, the sterilization target C moves from the holding arm A of one turning table to the holding arm of the other turning table. By being passed to A, the sterilization object C is conveyed so as to follow a circular path.

  A mounting plate T21 is provided above the second turning table T2 of the second transport device M2, as shown in FIG. The second turning table T2 and the mounting plate T21 are attached to a common rotation axis T22 and can be turned around the rotation axis T22. An inner surface sterilization emitter E2 is provided at a location above the holding arm A of the mounting plate T21. Moreover, between the 2nd turning table T2 and the holding arm A, the raising / lowering body T23 is provided, respectively. The rotating shaft T22, the lifting body T23, and the inner surface sterilization emitter E2 are each connected to the control unit CU.

  The control device CU rotates the rotary shaft T22, so that the inner surface sterilization emitter E2 rotates together with the sterilization target C. During this time, the control device CU raises and lowers the lifting body T23 in the axial direction V, so that the sterilization target C held by the holding arm A is also raised and lowered. Thereby, the nozzle 24a of the inner surface sterilization emitter E2 is inserted into the sterilization target C. In this state, the control unit CU irradiates the inner surface sterilization emitter E2 with an electron beam. As a result, as shown in FIG. 2, the electrons irradiated from the nozzle 24a are scattered in the atmosphere to form an electron cloud, and the inner surface sterilization emitter E2 sterilizes the inner surface of the sterilization target C.

  The outer surface sterilization emitter E1 is provided on the mounting plate T21 similarly to the inner surface sterilization emitter E2, but is provided at a location other than the location above the holding arm A. Specifically, as shown in FIG. 1, the outer surface sterilization emitter E1 is disposed on the transport path R and between the inner surface sterilization emitters E2. That is, the outer surface sterilization emitter E1 and the inner surface sterilization emitter E2 are alternately arranged at equal pitches on the transport path R. The outer surface sterilization emitter E1 rotates together with the sterilization object C as the control unit CU rotates the rotation axis T22. The outer surface sterilization emitter E1 is connected to the control unit CU, and the control unit CU irradiates the outer surface sterilization emitter E1 with an electron beam. Thereby, as shown in FIG. 2, the electrons irradiated from the nozzle 14a are scattered in the atmosphere to form an electron cloud, and the outer surface sterilization emitter E1 sterilizes the outer surface of the sterilization target C. Thereby, even when the outer surface sterilization emitter E1 sterilizes the outer surface, the sterilization object C can be moved in the axial direction V by the elevating body T23 of the transport device M2.

  When the outer surface sterilization emitter E1 and the inner surface sterilization emitter E2 irradiate an electron beam, radiation such as X-rays harmful to the human body is generated. The radiation shield S shown in FIG. 1 surrounds a part of the transport path R in order to block such radiation. A plurality of sterilization chambers R <b> 1 to R <b> 3 are formed by the radiation shield S surrounding a part of the transport path R. Each of the sterilization chambers R1 to R3 is provided with one transfer device M1 to M3. All the outer surface sterilization emitters E1 and the inner surface sterilization emitter E2 are provided in the same sterilization chamber R2.

  Next, specific configurations of the outer surface sterilization emitter and the inner surface sterilization emitter according to the present embodiment will be described with reference to FIG. The outer surface sterilization emitter E <b> 1 includes a power supply 11, a cathode 12, an electron lens 13, a flange 14, and a chamber 15. Similarly to the outer surface sterilization emitter E1, the inner surface sterilization emitter E2 includes a power supply 21, a cathode 22, an electron lens 23, a flange 24, and a chamber 25.

  The cathode 12 (22) is connected to the power supply 11 (21), and the “dual of the cathode 12 (22) and the electron lens 13 (23)” is negative when a voltage is applied from the power supply 11 (21). It becomes a potential. Further, the current is supplied from the power supply 11 (21) to the cathode 12 (22), whereby heat is applied to the cathode 12 (22). Then, when heat is applied to the cathode 12 (22), electrons inside the cathode 12 (22) are excited.

  The flange 14 (24) has a nozzle 14a (24a). Further, the flange 14 (24) is grounded and has a higher potential than the “dual pair of the cathode 12 (22) and the electron lens 13 (23)”, which is a negative potential when a voltage is applied. Thereby, an electric field is generated in a direction from the flange 14 (24) toward the cathode 12 (22). The electric field may be strengthened by increasing the acceleration voltage between the “dual of the cathode 12 (22) and the electron lens 13 (23)” and the flange 14 (24).

  The chamber 15 (25) surrounds the cathode 12 (22) and the electron lens 13 (23). Moreover, the window part 14b (24b) which can pass an electron beam is provided in the front end surface of the nozzle 14a (24a) of the flange 14 (24). A closed space is formed by the flange 14 (24) and the chamber 15 (25). This space is maintained in a vacuum state by a vacuum pump 15a (25a) connected to the chamber 15 (25).

  The electron lens 13 (23) is a conductor such as a metal and surrounds the cathode 12 (22) except for the opening 13a (23a). Similarly to the cathode 12 (22), the electron lens 13 (23) is connected to the power supply 11 (21), and has substantially the same potential as the cathode 12 (22).

  Since the electron lens 13 (23) is a conductor, the electric field in the direction from the flange 14 (24) toward the cathode 12 (22) is blocked except for the portion where the opening 13a (23a) is formed. In other words, the electric field in the direction from the flange 14 (24) toward the cathode 12 (22) acts only on the portion of the cathode 12 (22) located at the location where the opening 13a (23a) is formed. Then, the electrons excited on the cathode 12 (22) are emitted from the portion of the cathode 12 (22) where the electric field acts, and the electron beam is emitted from the opening 13a (23a), the nozzle 14a (24a), and the window 14b (24b). ) To the outside of the sterilization emitter E1 (E2).

  In other words, the outer surface sterilization emitter E1 and the inner surface sterilization emitter E2 are so-called thermoelectron emission type electron beam emitters that accelerate by applying an electric field to electrons excited by heat. The irradiation intensity of the electron beam in this type of electron beam emitter depends on the value of the current supplied to the cathode 12 (22) and the value of the electric field (acceleration voltage) between the cathode 12 (22) and the flange 14 (24). Dependent. Such current values and acceleration voltage values are controlled by the control unit CU (see FIG. 3). Thereby, the control apparatus CU can control the irradiation intensity | strength of the electron beam of the outer surface sterilization emitter E1 and the inner surface sterilization emitter E2.

  According to the electron beam sterilization system 1 according to the present embodiment, when the outer surface sterilization emitter E1 sterilizes the outer surface of the sterilization target C, the sterilization target C moves up and down in the axial direction V. Therefore, in the axial direction V, the sterilization of the entire outer surface of the sterilization target C can be made uniform. For example, in the conventional electron beam sterilization system shown in FIGS. 14 and 15, the entire outer surface of the sterilization target C is sterilized by the fixed outer surface sterilization emitters E3 and E4. That is, when sterilizing the outer surface of the sterilization target C, the sterilization target C and the outer surface sterilization emitters E3 and E4 move relatively only in the direction in which the sterilization target C is conveyed.

  Therefore, the distance between the sterilization target C and the outer surface sterilization emitters E3 and E4 is different for each portion of the sterilization target C. For example, when the sterilization target C has a neck and a body, the neck of the sterilization target C has a large distance from the outer surface sterilization emitters E3 and E4, whereas the body of the sterilization target C has an outer surface sterilization emitter E3. , E4 distance is small. In order to reliably sterilize a neck having a large distance, the irradiation intensity of the outer surface sterilization emitters E3 and E4 may be increased or the conveyance speed of the sterilization target C may be decreased. There was a problem that sterilization of the outer surface of the object C to be sterilized became non-uniform because the electron beam was irradiated.

  In this regard, according to the electron beam sterilization system according to the present embodiment, when the outer surface of the sterilization target C is sterilized, the sterilization target C moves up and down in the axial direction V, so that the sterilization target C and the outer surface sterilization emitter E1. The relative height of the sterilization object C also changes when the outer surface of the sterilization target C is sterilized. Therefore, the irradiation intensity of the outer surface sterilization emitter E1 and the elevation speed of the sterilization target C can be controlled according to the relative height between the sterilization target C and the outer surface sterilization emitter E1. That is, when the window part 14b of the outer surface sterilization emitter E1 is located in the vicinity of the neck part, the irradiation part of the outer surface sterilization emitter E1 is increased, or the ascending / descending speed of the sterilization object C is decreased, so that the neck part can be securely attached. Can be sterilized. Thereby, the sterilization of the entire outer surface of the sterilization target C can be made uniform in the axial direction V. The control device CU can control the irradiation intensity of the outer surface sterilization emitter E1 and the ascending / descending speed of the sterilization target C according to the height of the sterilization target C.

  The position at which the sterilization target C starts to move up and down is preferably in a region where the sterilization target C is not affected by the electron beam irradiated from the outer surface sterilization emitter E1. In this case, the sterilization of the entire outer surface of the sterilization target C can be made more uniform. Suppose that the window portion 14b of the outer surface sterilization emitter E1 is located in the vicinity of the height of the body portion of the sterilization target C at the time when sterilization of the outer surface of the sterilization target C starts. At this time, when the sterilization target C has not started to move up and down, that is, when the sterilization target C is stationary in the axial direction V, the body of the sterilization target C is longer than the other parts. It will be affected by the electron beam. Therefore, there is a possibility that the body part of the sterilization target C is excessively irradiated with an electron beam, and sterilization of the entire outer surface of the sterilization target C becomes nonuniform.

  In this regard, when the position at which the sterilization target C starts to rise and fall is within a region where the sterilization target C is not affected by the electron beam irradiated from the outer surface sterilization emitter E1, a part of the sterilization target C is located. Can be prevented from being affected by the electron beam for a longer time than other parts. Thereby, sterilization of the entire outer surface can be made more uniform. For the same reason, the position where the sterilization target C ends up and down is preferably within the region where the sterilization target C is not affected by the electron beam irradiated from the outer surface sterilization emitter E1. Here, examples of the “region not affected by the electron beam” include a region far from the window portion 14b of the outer surface sterilization emitter E1 to the extent that it is not affected by the electron beam, and a shielding material that shields the electron beam. Examples include an area partitioned from the window portion 14b of the outer surface sterilization emitter E1.

  Moreover, according to the electron beam sterilization system 1 according to the present embodiment, the outer surface sterilization emitter E1 is configured to move in the transport direction together with the sterilization target C. Thereby, the efficiency of the sterilization process of the sterilization target C can be improved. For example, in the conventional electron beam sterilization system 5 shown in FIG. 14, since the outer surface sterilization emitters E3 and E4 are fixed, the distance between the sterilization object C and the outer surface sterilization emitters E3 and E4 changes with time. It becomes. Therefore, in order to sufficiently sterilize the outer surface of the sterilization target C, it is necessary to increase the electron beam intensity of the outer surface sterilization emitters E3 and E4, or to reduce the transport speed of the sterilization target C. This has been a cause of reducing the efficiency of sterilization of objects. Specifically, in the conventional electron beam sterilization system 5, when the conveyance speed of the sterilization target C is increased, the time during which the outer surface sterilization emitters E3 and E4 are located in the vicinity of the sterilization target C is shortened. In order to sufficiently perform the outer surface sterilization of C, it is necessary to increase the intensity of the electron beams of the outer surface sterilization emitters E3 and E4.

  In this regard, according to the electron beam sterilization system 1 according to the present embodiment, the outer surface sterilization emitter E1 moves in the direction of transport together with the sterilization target C, and therefore the sterilization target C and the outer surface sterilization emitter E1 are transported. The distance in the direction can be constant. Therefore, the outer surface of the sterilization target C can be sterilized regardless of the conveyance speed of the sterilization target C. Thereby, compared with the conventional electron beam sterilization system 5, the efficiency of the sterilization process of the sterilization target C can be improved. For example, in the electron beam sterilization system 1 according to the present embodiment, even if the conveyance speed of the sterilization object C is increased, the external sterilization emitter E1 also moves in the conveyance direction together with the sterilization object C. A sufficient amount of time is located in the vicinity of the sterilization target C. Therefore, even if the conveyance speed of the sterilization target C is increased, it is not necessary to increase the strength of the outer surface sterilization emitter E1.

  Further, since the time during which the outer surface sterilization emitter E1 is located in the vicinity of the sterilization target C is longer than that of the conventional electron beam sterilization system, the sterilization target can be obtained even if the irradiation intensity of the electron sterilization emitter E1 is lowered. The outer surface of C can be sufficiently sterilized. Thereby, the energy required for sterilization of the outer surface can be reduced, and the efficiency of outer surface sterilization can be improved.

  Here, since both the outer surface sterilization emitter E1 and the inner surface sterilization emitter E2 are nozzle emitters, they can have the same structure and specifications. For example, in the conventional electron beam sterilization system shown in FIGS. 14 to 16, the outer surface sterilization emitters E3 and E4 are flat emitters, whereas the inner surface sterilization emitter is a nozzle emitter. For this reason, the specifications of the outer surface sterilization emitter and the inner surface sterilization emitter are greatly different, which complicates the entire system. On the other hand, the system can be simplified by setting the outer surface sterilization emitter E1 and the inner surface sterilization emitter E2 to the same specification. Further, the structure of the nozzle 14a of the outer surface sterilization emitter E1 may be different from the nozzle 24a of the inner surface sterilization emitter E2.

  For example, as shown in FIG. 5, the diameter D1 of the outer surface sterilization emitter nozzle 14a may be larger than the diameter D2 of the inner surface sterilization emitter nozzle 24a. Although the inner surface sterilization emitter nozzle 24a is designed to be inserted into the sterilization object C, the outer surface sterilization emitter nozzle 14a is not inserted into the sterilization object C, and thus does not have such a restriction. Furthermore, when the diameter of the nozzle 14a is increased, it is considered that the electron cloud is easily scattered around and the outer surface of the sterilization target C is easily sterilized.

  Further, as shown in FIG. 6, the length L1 of the outer surface sterilization emitter nozzle 14a may be smaller (shorter) than the length L2 of the inner surface sterilization emitter nozzle 24a. In this case, the upper part of the sterilization target C is easily sterilized. On the other hand, as shown in FIG. 7, the length L1 of the nozzle 14a of the outer surface sterilization emitter may be larger (longer) than the length L2 of the nozzle 24a of the inner surface sterilization emitter. In this case, the lower part of the sterilization target C is easily sterilized. Here, the length L1 of the outer surface sterilization emitter E1 and the length L2 of the inner surface electron beam emitter E2 mean the length of the nozzle 14a (24a) protruding from the lower surface of the mounting plate T21 (see FIG. 3). To do. Therefore, even if the outer surface sterilization emitter E1 and the inner surface sterilization emitter E2 have the same nozzle, if the length of the nozzle protruding from the lower surface of the mounting plate T21 is different, the length of the nozzle 14a of the outer surface sterilization emitter E1. The length L1 is different from the length L2 of the nozzle 24a of the inner surface sterilization emitter E2.

  Further, as described above, the window portion 14b through which the electron beam can pass is provided on the distal end surface of the nozzle 14a of the outer surface sterilization emitter. Here, as shown in FIGS. 8A and 9A, the outer surface sterilization emitter nozzle 14a has, in addition to the window portion 14b provided on the tip surface, another window portion 14c provided on the side surface around the tip surface. May be. By providing a window portion 14c on the side surface around the distal end surface of the nozzle 14a of the outer surface sterilization emitter, an electron cloud irradiated from the outer surface sterilization emitter is emitted around the nozzle 14a as shown in FIGS. 8B and 9B. Therefore, it is considered that the outer surface of the sterilization target C can be easily sterilized. The tip shape of the nozzle 14a may be a tapered shape with a narrow tip as shown in FIGS. 8A and 8B, or a cylindrical shape as shown in FIGS. 9A and 9B.

  Furthermore, the irradiation intensity of the outer surface sterilization emitter E1 may be controlled to be different from the irradiation intensity of the inner surface sterilization emitter E2. The irradiation intensity of the external sterilization emitter E1 is controlled based on the graph shown in FIG. 10 by the control unit CU, for example. The horizontal axis of the graph shown in FIG. 10 indicates the distance [mm] in the atmosphere from the window portion of the nozzle of the electron beam emitter to the sterilization target C. The vertical axis | shaft of the graph of FIG. 10 shows the relative dose with respect to the sterilization target object C of the electron beam irradiated from an electron beam emitter. This relative dose indicates an index as to whether or not the sterilization target C has a sufficient sterilization effect.

  As described above, electrons emitted from the window portion are scattered in the atmosphere to form an electron cloud. However, as the distance from the window portion increases, energy is gradually lost. Here, the dose is a function of the beam current, electron energy and exposure time, and how much electron energy is lost depends on the electron energy of the electron beam emitter. For example, as shown in FIG. 10, when the electron energy is 90 keV, when the distance between the nozzle window and the sterilization target C is 50 mm, the relative dose is about 15%, and the sterilization effect is sufficiently obtained. It will not be. On the other hand, when the electronic energy is 175 keV, even if the distance between the nozzle window and the sterilization object C is 100 mm, the relative dose is approximately 100%, and a sufficient sterilization effect is obtained.

  For the inner surface sterilization emitter E2, the distance from the window 24b to the sterilization object C is, for example, 4 mm. In this case, the energy of electrons lost due to scattering is negligibly small. On the other hand, the outer surface sterilization emitter E1 may be provided at a position where the distance from the window portion 14b to the sterilization target C is, for example, 100 mm away. In this case, if the electron energy of the outer surface sterilization emitter E1 is 125 keV, the relative dose is about 40%, and a sufficient sterilization effect cannot be obtained. On the other hand, if the electron energy of the external sterilization emitter E1 is increased to 150 keV, the relative dose is about 80%, and if it is increased to 175 keV, the relative dose is about 100%, and a sufficient sterilization effect is obtained.

  Also, instead of increasing the electron energy of the outer surface sterilization emitter E1, or at the same time, by arranging the window portion 14b so as to reduce the distance between the window portion 14b of the outer surface sterilization emitter E1 and the sterilization object C. Sufficient sterilization effect can be obtained. For example, when the distance between the nozzle 14b of the outer surface sterilization emitter E1 and the sterilization target C is 25 mm, the electron energy of the electron beam of the outer surface sterilization emitter E1 is 110 keV and the relative dose is 80% or more. It becomes possible to sterilize effectively. In order to effectively sterilize the outer surface of the object C to be sterilized, the window portion 14b of the outer surface sterilization emitter E1 is arranged or the outer surface sterilization emitter E1 so that the relative dose is 60% or more, more preferably 80% or more. It is sufficient to control the electron energy.

  In addition, in the electron beam sterilization system 1 which concerns on this Embodiment, although the outer surface sterilization emitter E1 and the inner surface sterilization emitter E2 were alternately arrange | positioned on the conveyance path | route R, the aspect was described, but it is not restricted to this. For example, two outer surface sterilization emitters E1 may be continuously provided for one inner surface sterilization emitter E2. The inner surface sterilization emitter E2 needs to be provided on the transport path R in order to insert the nozzle 24a into the sterilization target C, but the outer surface sterilization emitter E1 is disposed on the transport path R. There is no need.

  For example, as shown in FIG. 11, the outer surface sterilization emitter nozzle 14a may be provided so as to surround four sides around the inner surface sterilization emitter nozzle 24a in plan view, and as shown in FIG. The outer surface sterilization emitter nozzle 14a may be provided so as to surround three sides around the inner surface sterilization emitter nozzle 24a. The outer surface of the sterilization target C can be sterilized more reliably when the distance between the nozzle 14a of the external sterilization emitter and the sterilization target C is short and the number of the external sterilization emitters is large.

  In the electron beam sterilization system according to the present embodiment, the mode in which the transport devices M1 to M3 transport the sterilization target object C so that the sterilization target object C follows the circular transport path R has been described. I can't. For example, as shown in FIG. 13, instead of the transfer devices M1 to M3, a transfer device M4 such as a conveyor for transferring the sterilization target C so that the sterilization target C follows a linear transfer path R ′ is adopted. Also good. The nozzle 24a of the inner surface sterilization emitter is continuously arranged on the linear conveyance path R ′. The nozzle 14a of the outer surface sterilization emitter may be arranged so that the nozzle 24a of the inner surface sterilization emitter and the nozzle 14a of the outer surface sterilization emitter are in a lattice pattern, or may be arranged in a staggered pattern.

  In addition, in the electron beam sterilization system 1 which concerns on this Embodiment, although the outer surface sterilization emitter E1 and the inner surface sterilization emitter E2 were provided in the same sterilization chamber R2, the aspect was not restricted. Even if the inner surface sterilization emitter and the outer surface sterilization emitter are provided in separate sterilization chambers, the object of the present invention is solved as long as the outer surface sterilization emitter E1 and the object C to be sterilized are relatively in the axial direction. Is possible. When the outer surface sterilization emitter E1 and the inner surface sterilization emitter E2 are provided in the same sterilization chamber, the inner surface and the outer surface of the object C to be sterilized can be sterilized at the same time. And the entire system can be downsized.

  In the electron beam sterilization system 1 according to the present embodiment, the mode in which the nozzle 24a of the inner surface sterilization emitter E2 is inserted into the sterilization target C by moving the holding arm A up and down in the axial direction V has been described. If the inner surface sterilization emitter E2 and the object to be sterilized C can be moved relative to each other in the axial direction V, the nozzle 24a of the inner surface sterilization emitter E2 can be inserted into the inner surface of the object to be sterilized. It becomes. For example, instead of moving the holding arm A, the nozzle 24a of the inner surface sterilization emitter E2 may be inserted into the sterilization object C by raising and lowering the inner surface sterilization emitter E2 in the axial direction V. At this time, the outer surface sterilization emitter E1 may also be moved up and down in the axial direction V. Further, the holding arm A may be configured to move in a direction in which the nozzle 24 a of the inner surface sterilization emitter E <b> 2 enters and exits the sterilization target C without being limited to the axial direction V.

  Further, the relative movement between the outer surface sterilization emitter E1 and the sterilization object C is not limited to the axial direction V. If the outer surface sterilization emitter E1 and the object to be sterilized can be moved in a direction different from the direction of conveyance of the object to be sterilized C, it is possible to contribute to uniform sterilization of the entire outer surface of the object to be sterilized C. Moreover, although the conveyance apparatus M2 described the aspect which moves the outer surface sterilization emitter E1 and the sterilization target object C relatively, it is not restricted to this. A relative movement device that relatively moves the outer surface sterilization emitter E1 and the sterilization target C in a direction different from the direction of conveyance of the sterilization target C may be provided separately.

  Although the outer surface sterilization emitter E1 and the inner surface sterilization emitter E2 are so-called thermoelectron emission type electron beam emitters, the present invention is not limited thereto. The outer surface sterilization emitter and the inner surface sterilization emitter of the present invention may be, for example, a so-called field emission type electron beam emitter that irradiates an electron beam with an electric field without thermally exciting electrons. Moreover, although the aspect provided with both the outer surface sterilization emitter E1 and the inner surface sterilization emitter E2 was described, it is not restricted to this. For example, when the sterilization target C does not have an inner surface, or when the sterilization of the inner surface of the sterilization target C has already been completed, the inner sterilization emitter E2 is not provided, but only the outer sterilization emitter E1 is provided. May be.

  In the sterilization system 1 according to the present embodiment, the outer surface sterilization emitter E1 and the inner surface sterilization emitter E2 are each an electron beam emitter having a nozzle, that is, a nozzle emitter, but is not limited thereto. In particular, the outer surface sterilization emitter E1 may be a flat emitter as shown in FIG. Further, the electron lens 13 is not limited to one including one opening 13a. When the outer surface sterilization emitter E1 is a flat emitter, the electron lens 13 includes a plurality of openings 13a like a grid structure. Moreover, although the outer surface sterilization emitter E1 and the inner surface sterilization emitter E2 each have one nozzle 14a (24a) for one chamber 15 (25), the embodiment is not limited thereto. For example, a plurality of nozzles 14a (24a) may be provided in the chamber 15 (25) of the outer surface sterilization emitter E1 or the inner surface sterilization emitter E2. Further, the nozzle 14a of the outer surface sterilization emitter E1 and the nozzle 24a of the inner surface sterilization emitter E2 may share one chamber. Whatever specifications the outer surface sterilization emitter adopts, when the outer surface sterilization emitter E1 and the sterilization target object C move relative to each other in the axial direction when sterilizing the outer surface of the sterilization target C, the problem of the present invention is solved. It becomes possible to do. Further, in the electron beam sterilization system according to the present embodiment, the sterilization target C may be conveyed continuously or intermittently.

[Embodiment 2]
In the electron beam sterilization system 1 according to the first embodiment, the aspect in which the outer surface sterilization emitter E1 moves together with the sterilization target C has been described. However, in the electron beam sterilization system according to the second embodiment, the outer surface sterilization emitter is sterilized. It can move in the direction of approaching or moving away from the object. Hereinafter, the points different from the first embodiment will be described in detail.

  The transport apparatus M4 and the like shown in FIG. 13 intermittently transport the sterilization target C, that is, once stop the transport for sterilization of the sterilization target C, and again transport the sterilization target when the sterilization is completed. May resume. In this case, the inner surface sterilization emitter can be moved up and down so that the nozzle 24 a can be inserted into the sterilization target C while the conveyance of the sterilization target C is stopped.

  In the electron beam sterilization system according to the present embodiment, the outer surface sterilization emitter can also be moved up and down because the nozzle 14a moves relative to the sterilization target C. On the other hand, in order to sterilize the outer surface of the sterilization target C while the sterilization target C is stopped, the outer surface sterilization emitter may not be configured to move together with the sterilization target C. Since the outer surface sterilization emitter can be moved up and down, sterilization of the entire outer surface of the sterilization target C can be made uniform in the axial direction V.

In addition, although the electron beam sterilization system which concerns on this Embodiment described the aspect which employ | adopts the conveying apparatus M4, it is not restricted to this, You may employ | adopt the conveying apparatuses M1-M3 shown in FIG. Moreover, although the aspect which raises / lowers an outer surface sterilization emitter was described, it is not restricted to this. If the outer surface sterilization emitter and the sterilization target C can be moved relative to each other in a direction different from the direction in which the sterilization target C is conveyed, the problem of the present invention can be solved. The outer surface sterilization emitter is not limited to the nozzle emitter, and may be a flat emitter.

Claims (8)

An electron beam sterilization system for sterilizing an object to be sterilized while transporting along a transport path,
An outer surface sterilization emitter for sterilizing by irradiating the outer surface of the object to be sterilized with an electron beam;
An electronic apparatus comprising: a relative movement device that relatively moves the sterilization target object and the outer surface sterilization emitter in a direction different from a direction of transport along the transport path when sterilizing the outer surface of the sterilization target object. Wire sterilization system. The electron beam sterilization system according to claim 1, wherein the outer surface sterilization emitter is configured to move in a direction in which the sterilization target is transported together with the sterilization target being transported. An inner surface sterilization emitter that sterilizes by irradiating the inner surface of the object to be sterilized with an electron beam;
And at least one sterilization chamber surrounding a part of the transport path,
The electron beam sterilization system according to claim 1, wherein the outer surface sterilization emitter and the inner surface sterilization emitter are provided in the same sterilization chamber. An inner surface sterilization emitter for sterilizing by irradiating the inner surface of the object to be sterilized with an electron beam;
The electron beam sterilization system according to claim 1, wherein the relative movement device moves the sterilization target object relative to the outer surface sterilization emitter and the inner surface sterilization emitter. An inner surface sterilization emitter for sterilizing by irradiating the inner surface of the object to be sterilized with an electron beam;
The inner surface sterilization emitter and the outer surface sterilization emitter each have a nozzle, and are nozzle emitters that sterilize the sterilization target by irradiating the sterilization target with an electron beam from the nozzle. Item 2. The electron beam sterilization system according to Item 1. 6. The electron beam sterilization system according to claim 5, wherein the nozzle of the outer surface sterilization emitter has a larger diameter and / or longer or shorter than the nozzle of the inner surface sterilization emitter. The outer surface sterilization emitter is a nozzle emitter that has a nozzle and sterilizes the sterilization object by irradiating the sterilization object with an electron beam from the nozzle,
2. The electron beam sterilization system according to claim 1, wherein the nozzle of the outer surface sterilization emitter has, in addition to the window portion provided on the distal end surface, another window portion provided on a side surface around the distal end surface. . An inner surface sterilization emitter for sterilizing by irradiating the inner surface of the object to be sterilized with an electron beam;
2. The electron beam sterilization according to claim 1, wherein the outer surface sterilization emitter and the inner surface sterilization emitter are configured to move together with the sterilized object to be transported in a direction in which the sterilized object is transported. system.

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