JP4848172B2 - Electron beam sterilization system - Google Patents

Description

  The present invention relates to a system for performing sterilization using an electron beam.

  Products in which hygiene is important, such as food containers and medical devices, are sterilized in the manufacturing process. Usually, sterilization (called wet sterilization) is performed using a chemical exemplified by hydrogen peroxide. Confirmation that the sterilization is performed to a desired degree is performed, for example, by culturing the sterilized product as a sample and measuring the propagation of microorganisms.

  A technique for sterilizing using an electron beam instead of using a drug has been studied. Sterilization using an electron beam (referred to as dry sterilization) is superior in that the cost of the drug is not required and the step of rinsing the drug is not required because no drug is used.

Patent Document 1 describes an electron beam / X-ray irradiation system. The electron beam / X-ray irradiation system includes: an X-ray irradiation apparatus; an X-ray measurement apparatus that measures X-rays transmitted through the irradiated object; And a control means for controlling the electron beam / X-ray irradiated to the irradiated object using the density distribution.
JP 2002-221599 A

  When a food container is sterilized using an electron beam, the food container is not sufficiently sterilized if the irradiation amount of the electron beam is insufficient. If the irradiation amount of the electron beam is excessive, an undesirable change such as discoloration of the food container occurs. A technique for supplying an electron beam with an appropriate irradiation amount is desired.

  The objective of this invention is providing the electron beam sterilization system which controls the irradiation amount of the electron beam irradiated to a target object in the suitable range.

  In the following, means for solving the problem will be described using the numbers used in [Best Mode for Carrying Out the Invention] in parentheses. These numbers are added to clarify the correspondence between the description of [Claims] and [Best Mode for Carrying Out the Invention]. However, these numbers should not be used to interpret the technical scope of the invention described in [Claims].

  An electron beam sterilization system according to the present invention includes a transport device (20), an electron beam irradiation device (30) for irradiating a food container (10) transported by the transport device (20), and an electron beam irradiation device ( 30) a storage unit (59) for storing a condition for the control value to be appropriate, and a determination unit (50) for determining whether the control value satisfies the condition.

  The electron beam sterilization system according to the present invention includes a current detector that measures the current value of the beam current of the electron beam generated by the electron beam irradiation device (30). The condition includes an allowable range of the current value.

  The electron beam sterilization system according to the present invention includes a defective product removing device (60) that removes the food container (10) determined by the determining unit (50) that the control value does not satisfy the condition.

  The electron beam sterilization system according to the present invention is provided on the upstream side of the defective product removing device (60), and the contents are placed in the food container (10) determined by the determination unit (50) that the control value satisfies the condition. A filling device (9) is provided that does not fill the food container when it is determined that the condition is not satisfied.

  In the electron beam sterilization system according to the present invention, the conditions include the allowable range of the acceleration voltage of the electron beam irradiation device (30).

  In the electron beam sterilization system according to the present invention, the electron beam irradiation device (30) includes an electron beam scanning unit (42) for scanning an electron beam. The conditions include conditions of scan control values used for controlling the electron beam scanning unit (42).

  In the electron beam sterilization system according to the present invention, the scan control value is a scan frequency.

  In the electron beam sterilization system according to the present invention, the scan control value is a scan width.

  An electron beam sterilization system according to the present invention includes a beam sensor (44) that is provided within an irradiation range of an electron beam by an electron beam irradiation device (30) and that outputs a detection signal indicating whether or not an electron beam is irradiated; A scan width determination unit (54) that compares the scan width indicated by the scan control value with the detection signal to determine consistency.

  The electron beam sterilization system according to the present invention includes a transport speed detector (55) that detects the transport speed of the food container (10) transported by the transport device (20), and whether the transport speed satisfies a predetermined speed condition. A conveyance speed condition determination unit (61) for determining whether or not.

  In the electron beam sterilization system according to the present invention, the storage unit (59) stores scan frequency-conveyance speed relationship data (56) for designating the relationship between the conveyance speed and the scanning control value. The electron beam sterilizer controls the electron beam scanning unit (42) using a scanning control value obtained from the conveyance speed detected by the conveyance speed detection unit (55) based on the scan frequency-conveyance speed relationship data (56). A scanning control value adjustment unit (57) is provided.

  ADVANTAGE OF THE INVENTION According to this invention, the electron beam sterilization system which controls the irradiation amount of the electron beam irradiated to a target object in an appropriate range is provided.

  Hereinafter, the best mode for carrying out an electron beam sterilization system according to the present invention will be described with reference to the drawings. The electron beam sterilization system in the present embodiment is used to sterilize food containers exemplified by PET bottles.

  FIG. 1 is a diagram schematically showing the configuration of a food container / beverage filling system that sterilizes food containers with an electron beam, fills the contents, and caps them. The food container / beverage filling system includes a sterilization chamber 3, a rinse rinser chamber 4, a filling chamber 5, and a capper chamber 6. These are all clean rooms.

  The food container is carried into the sterilization chamber 3 from the inlet 2. The carried food container is transported to the sterilization unit 40 by the transport device 20 and sterilized by the electron beam irradiation device 30. The sterilized food container is transported to the rinse rinser chamber 4 by the transport device. The food container is rinsed with water or air by a rinse rinser 8 installed in the rinse rinser chamber 4. In the present invention in which electron beam sterilization is performed, the rinse rinser 4 may be unnecessary. The rinsed food container is transported to the filling chamber 5 by the transport device. A filling device 9 installed in the filling chamber 5 fills a food container with a beverage. The food container filled with the beverage is transported to the capper chamber 6 by the transport device. A capper device 11 installed in the capper chamber 6 attaches a cap to a food container. The food container fitted with the cap is carried out from the outlet.

  FIG. 2 is a diagram for explaining a configuration in the vicinity of the sterilization unit 40. An electron beam irradiation device 30 is installed in the sterilization unit 40. The electron beam irradiation apparatus 30 includes an electron beam supply unit 41 that generates an electron beam, an electron beam scanning unit 42 that scans the generated electron beam, and a tip of an electron beam scan horn (on the side close to the food container to be irradiated). The electron beam irradiation port 43 is provided at the opening end of the device. The electron beam irradiation apparatus 30 further includes a current detector that detects a beam current that is a current value of the output circuit of the electron beam. The current detector is, for example, a CT (Current Transformer) or a shunt resistor.

  The electron beam irradiation apparatus 30 further includes a beam sensor 44 that detects the presence or absence of an electron beam and generates an electron beam detection signal indicating the result. A plurality of beam sensors 44 are preferably installed along the scanning direction. For example, if the electron beam is scanned from the first point (scanning start position) to the second point (scanning end position) at the electron beam irradiation port 43, the beam sensor 44 is moved to the first point or a little second point. It is installed on the side closer to the second point or to the side closer to the first point.

  The sterilization unit 40 is provided with a control unit 46. The control unit 46 controls the transport speed of the transport device 20. The electron beam supply unit 41, the electron beam scanning unit 42, the beam sensor 44, and the control unit 46 are communicably connected to a computer 51, and the computer 51 controls the conveyance speed and the electron beam irradiation method.

  The position monitoring device 58 monitors the position of each of the plurality of food containers 10 being transported by the transport device 20. When the position monitoring device 58 receives from the computer 51 a removal signal indicating that an electron beam is not properly irradiated to a certain food container in the sterilization unit 40, the position monitoring device 58 performs the following processing on the food container. When the food container 10 is transported to the position where the content is filled by the filling device 9, the position monitoring device 58 notifies the control device 7 of a beverage filling non-use signal indicating that beverage filling is unnecessary. When the food container 10 is transported to a position where the defective product removing device 60 operates, a removal signal indicating that the food container 10 should be removed from the transport line is transmitted to the control device 7.

  When acquiring the filling unnecessary signal from the position monitoring device 58, the control device 7 controls the operation of the filling device 9 so that the filling device 9 does not fill the food container 10 with the contents. By not filling the contents in this way, the material cost of the contents can be reduced. Furthermore, when acquiring the removal signal from the position monitoring device 58, the control device 7 controls the operation of the defective product removing device 60 so that the defective product removing device 60 removes the food container 10 from the production line.

  The defective product removing device 60 is provided between the filling device 9 and the capper device 11. The defective product removing device 60 operates in accordance with an instruction from the control device 7 and removes the food container 10 determined to be defective from the manufacturing path. The defective product removing device 60 may be provided at another position as long as it is a subsequent process of the sterilization unit 40. When the defective product removing device 60 is provided between the sterilizing unit 40 and the filling device 9, the control device 7 controls the filling device 9 so that the food container 10 is not filled with the contents described above. This operation is omitted.

  FIG. 3 is a diagram schematically showing the configuration of the computer 51. The computer 51 includes an arithmetic processing unit 71, a ROM 73, a RAM 72, and a storage unit 59, which are connected to each other via a bus. The ROM 73 stores an electron beam irradiation condition determination unit 50 that is a computer program that is read and executed by the arithmetic processing unit 71.

  FIG. 4 is a diagram conceptually showing information stored in the storage unit 59. The storage unit 59 stores in advance predetermined ranges for beam current, acceleration voltage, scan frequency, scan width, and conveyance speed. The storage unit 59 further stores scan frequency-conveyance speed relationship data 56. The scan frequency-conveyance speed relationship data 56 indicates the relationship between the scan frequency and the conveyance speed in a table or function form.

  Returning to FIG. 3, the electron beam irradiation condition determination unit 50 includes an electron beam generator monitoring unit 52, a scan condition monitoring unit 53, a scan width determination unit 54, a conveyance speed detection unit 55, a scan control value adjustment unit 57, and a conveyance speed condition. A determination unit 61 is provided.

  The electron beam generator monitoring unit 52 compares the recorded numerical value and the detected numerical value of the storage unit 59 to determine whether it is good or bad, and determines whether the beam current detected by the current detector is within a predetermined range. to decide.

  The scan condition determination unit 53 refers to the storage unit 59 to determine whether or not the scan frequency, which is a control value used for the electron beam scanning unit 42 to scan the electron beam, is within a predetermined range.

  The scan width determination unit 54 refers to the storage unit 59, and the scan width (range in which the electron beam is scanned at the electron beam irradiation port 43, which is a control value used by the electron beam scanning unit 42 to scan the electron beam, Alternatively, it is determined whether or not an angle range in which an electron beam supplied from a fixed electron beam supply unit is refracted by a magnetic field and deflected is within a predetermined range. The scan width determination unit 54 further receives an electron beam detection signal from the beam sensor 44.

  The conveyance speed detection unit 55 refers to the storage unit 59 and determines whether or not the conveyance speed, which is a control value of the speed used by the control unit 46 to drive the conveyance device 20, is within a predetermined range.

  FIG. 5 is a flowchart showing the operation of the electron beam sterilization system in the present embodiment. In the following description, an operation that the arithmetic processing device 71 included in the computer 51 reads a program stored in the electron beam irradiation condition determination unit 50 and executes according to the procedure described in the program is described as an operation performed by the program itself. Is done.

  The operation of the electron beam sterilization inspection system according to the present embodiment includes the step of irradiating an electron beam (step S10), the irradiation condition acquisition step of acquiring the irradiation condition of the electron beam (step S20), and the appropriateness of the acquired irradiation condition. A determination step (step S30) for determining the property, and a step of removing defective products (step S40).

(Step S10)
The electron beam supply unit 41 generates an electron beam. The electron beam scanning unit 42 periodically scans the generated electron beam by deflecting it. An electron beam is irradiated from the electron beam irradiation port 43 toward the food container on the transport device 20. The transport device 20 is driven. The food container 10 is carried in from the inlet 2. The food container 10 is transported to the sterilization unit 40 by the transport device 20 and irradiated with an electron beam by the electron beam irradiation device 30.

FIG. 6 is a flowchart showing the operation of the irradiation condition acquisition step (step S20).
(Step S21)
The electron beam generator monitoring unit 52 detects the current value of the beam current detected by a current detector, for example, CT, and stores it in the RAM 72. The electron beam generator monitoring unit 52 further acquires an acceleration voltage control value used for controlling the acceleration voltage and stores it in the RAM 72.

(Step S22)
The scan condition monitoring unit 53 acquires a scan frequency control value used for controlling the scan frequency of the electron beam scanning unit 42 and stores it in the RAM 72. The scan information monitoring unit 53 further acquires a scan width control value used for controlling the scan width and stores it in the RAM 72.

(Step S23)
The scan width determination unit 54 receives the electron beam detection signal from the beam sensor 44 and stores in the RAM 72 determination information indicating whether or not the beam has been scanned to the intended scan width.

(Step S24)
The conveyance speed detection unit 55 obtains a conveyance speed control value used for driving the conveyance device 20 from the control unit 46 and stores it in the RAM 72.

FIG. 7 is a flowchart showing the operation of the irradiation condition determining step (S30).
(Step S31)
The electron beam generator monitoring unit 52 refers to the storage unit 59 and transmits a removal signal to the position monitoring device 58 when the current value of the beam current stored in step S21 is not within a predetermined range. Further, the electron beam generator monitoring unit 52 refers to the storage unit 59 and transmits a removal signal to the position monitoring device 58 when the acceleration voltage control value acquired in step S21 is not within the predetermined range.

(Step S32)
The scan condition monitoring unit 53 refers to the storage unit 59 and sends a removal signal to the position monitoring device 58 when the scan frequency control value stored in step S22 is not within the predetermined range. The scan condition monitoring unit 53 further refers to the storage unit 59 and sends a removal signal to the position monitoring device 58 when the scan width control value stored in step S22 is not within the predetermined range.

(Step S33)
The scan width determination unit 54 refers to the storage unit 59 and transmits a removal signal to the position monitoring device 58 when the scan width stored in step S23 is not within the predetermined range. The scan width determination unit 54 further determines the consistency between the scan width control value stored in step S22 and the scan width stored in step S23, and sends a removal signal to the position monitoring device 58 if there is no match.

(Step S34)
The conveyance speed condition determination unit 61 refers to the storage unit 59 and determines whether or not the conveyance speed control value stored in step S24 is within a predetermined range. If it falls within the predetermined range, the process proceeds to step S35. If not within the predetermined range, the process proceeds to step S36.

(Step S35)
The scan condition monitoring unit 53 refers to the storage unit 59 and sends a removal signal to the position monitoring device 58 when the scan frequency control value stored in step S22 is not within the predetermined range.

(Step S36)
The scan control value adjustment unit 57 refers to the scan frequency-conveyance speed relationship data 56 of the storage unit 59 and calculates a scan frequency control value corresponding to the conveyance speed control value stored in step S24. The scanning control value adjustment unit 57 transmits the calculated scanning frequency control value to the electron beam scanning unit 42. The electron beam scanning unit 42 adjusts the scan frequency of the electron beam using the received scan frequency control value.

  By the process of step S36, for example, when the conveyance device 20 is started up or when the conveyance speed is urgently changed, the food container 10 is irradiated by changing the scan frequency in response to the change in the conveyance speed. The electron beam dose falls within an appropriate range.

  Although it is possible to change the beam current or the acceleration voltage when the conveyance speed 20 falls within a predetermined range, it is easy and desirable to change the scan frequency in order to control the irradiation amount to a desired range.

  The electron beam sterilization system in the present embodiment has a special effect as follows by appropriately controlling the irradiation amount of the electron beam. That is, in electron beam sterilization, when an object is irradiated with an electron beam, there is a certain relationship between the amount of electron beam irradiation and the proportion of microorganisms remaining on the object. Therefore, it can be expected that sterilization has been achieved to a desired level by controlling the irradiation amount of the electron beam within an appropriate range.

  These characteristics are different from those of sterilization systems using drugs. In a sterilization system using a drug, in order to confirm that sterilization is normally performed to a desired degree, microorganisms are cultured using the object as a sample, and the degree of propagation is observed. In the electron beam sterilization in the present embodiment, sterilization to a desired extent can be performed by irradiating the target with an electron beam in an appropriate range with certainty. Moreover, it is determined that filling is not necessary for an unsuitable food container, and removal is possible without filling. This realizes quantitative and reliable sterilization utilizing the characteristics of electron beam sterilization.

FIG. 1 shows the configuration of a food container beverage filling system. FIG. 2 is a diagram for explaining a configuration in the vicinity of the sterilization unit. FIG. 3 shows the configuration of the computer. FIG. 4 shows information stored in the storage unit. FIG. 5 is a flowchart showing the operation of the electron beam sterilization system. FIG. 6 is a flowchart showing the operation of the irradiation condition acquisition step. FIG. 7 is a flowchart showing the operation of the irradiation condition determination step.

Explanation of symbols

2 ... Entrance 3 ... Sterilization chamber 4 ... Rinsing chamber 5 ... Filling chamber 6 ... Capper chamber 7 ... Control device 8 ... Rinsing rinser 9 ... Filling device 10 ... Food container 11 ... Capper device 20 ... Conveying device 30 ... Electron beam irradiation device DESCRIPTION OF SYMBOLS 40 ... Sterilization part 41 ... Electron beam supply part 42 ... Electron beam scanning part 43 ... Electron beam irradiation port 44 ... Beam sensor 46 ... Control part 50 ... Electron beam irradiation condition judgment part 51 ... Computer 52 ... Electron beam generator monitoring part 53 ... Scanning condition monitoring unit 54 ... Scan width judging unit 55 ... Conveying speed detecting unit 56 ... Scanning frequency-conveying speed relation data 57 ... Scanning control value adjusting unit 58 ... Position monitoring device 59 ... Storage unit 60 ... Defective product removing device 61 ... Conveyance speed condition determination unit 71 ... arithmetic processing unit 72 ... RAM
73 ... ROM

Claims (10)

A transport device;
An electron beam irradiation device for irradiating an electron beam to the food container conveyed by the conveyance device;
A storage unit for storing conditions for proper control values of the electron beam irradiation device;
A determination unit that determines whether or not the control value satisfies the condition ;
A current detector for measuring a current value of an output circuit of an electron beam generated by the electron beam irradiation device;
The condition includes an allowable range of the current value,
Furthermore, a defective product removing apparatus that removes the food container that is determined by the determination unit that the control value does not satisfy the condition;
Provided on the upstream side of the defective product removal apparatus, the determination unit determines that the control value satisfies the condition, fills the food container with the contents, and determines that the condition is not satisfied An electron beam sterilization system comprising a filling device that does not fill the food container with contents . An electron beam sterilization system according to claim 1,
The electron beam irradiation apparatus includes an electron beam scanning unit that scans an electron beam,
The condition includes an electron beam sterilization system including a condition of a scanning control value used for controlling the electron beam scanning unit . An electron beam sterilization system according to claim 2,
The electron beam sterilization system , wherein the scan control value is a scan width . An electron beam sterilization system according to claim 2 or 3,
Furthermore, a transport speed detection unit that detects the transport speed of the food container transported by the transport device,
An electron beam sterilization system comprising: a transport speed condition determination unit that determines whether or not the transport speed satisfies a predetermined speed condition . A transport device;
An electron beam irradiation device for irradiating an electron beam to the food container conveyed by the conveyance device;
A storage unit for storing conditions for proper control values of the electron beam irradiation device;
A determination unit that determines whether or not the control value satisfies the condition;
A current detector for measuring a current value of an output circuit of an electron beam generated by the electron beam irradiation device;
The condition includes an allowable range of the current value,
The electron beam irradiation apparatus includes an electron beam scanning unit that scans an electron beam,
The condition includes a condition of a scanning control value used for controlling the electron beam scanning unit,
The electron beam sterilization system , wherein the scan control value is a scan frequency . A transport device;
An electron beam irradiation device for irradiating an electron beam to the food container conveyed by the conveyance device;
A storage unit for storing conditions for proper control values of the electron beam irradiation device;
A determination unit that determines whether or not the control value satisfies the condition;
A current detector for measuring a current value of an output circuit of an electron beam generated by the electron beam irradiation device;
The condition includes an allowable range of the current value,
The electron beam irradiation apparatus includes an electron beam scanning unit that scans an electron beam,
The condition includes a condition of a scanning control value used for controlling the electron beam scanning unit,
The scan control value is a scan width,
Furthermore, a beam sensor that is provided within an electron beam irradiation range by the electron beam irradiation device and outputs a detection signal indicating whether or not the electron beam is irradiated;
An electron beam sterilization system comprising: a scan width indicated by the scan control value and a scan width determination unit that compares the detection signal to determine consistency . A transport device;
An electron beam irradiation device for irradiating an electron beam to the food container conveyed by the conveyance device;
A storage unit for storing conditions for proper control values of the electron beam irradiation device;
A determination unit that determines whether or not the control value satisfies the condition;
A current detector for measuring a current value of an output circuit of an electron beam generated by the electron beam irradiation device;
The condition includes an allowable range of the current value,
The electron beam irradiation apparatus includes an electron beam scanning unit that scans an electron beam,
The condition includes a condition of a scanning control value used for controlling the electron beam scanning unit,
Furthermore, a transport speed detection unit that detects the transport speed of the food container transported by the transport device,
A transport speed condition determining unit that determines whether or not the transport speed satisfies a predetermined speed condition;
The storage unit stores scan frequency-conveyance speed relationship data that specifies a relationship between the conveyance speed and the scan control value,
Further, the electronic apparatus includes a scanning control value adjusting unit that controls the electron beam scanning unit using the scanning control value obtained from the conveyance speed detected by the conveyance speed detection unit based on the scan frequency-conveyance speed relationship data. Wire sterilization system. An electron beam sterilization system according to any one of claims 5 to 7,
Furthermore, the electron beam sterilization system which comprises the inferior goods removal apparatus which removes the said food container determined that the said control value does not satisfy | fill the said conditions by the said judgment part . An electron beam sterilization system according to claim 8,
Further, provided in the upstream side of the defective product removing apparatus, the content is filled in the food container that is determined by the determination unit that the control value satisfies the condition, and it is determined that the condition is not satisfied. An electron beam sterilization system comprising a filling device that does not fill the food container with the contents when the food container is filled .   An electron beam sterilization system according to any one of claims 1 to 9,
  The condition includes an allowable range of acceleration voltage of the electron beam irradiation apparatus.
  Electron beam sterilization system.

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