JPS58112928A - Electron-ray sterilizer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electron beam sterilizer for continuously sterilizing thin plate-shaped objects having a relatively small area, such as carton base paper used as packaging materials.

As technology advances in goods distribution, the scope of application of the so-called one-quay packaging system continues to expand, and many paper cartons are now being used to package various beverages such as milk. .

By the way, articles like this one, which are meant for food and drink, need to be sterilized before use.
Therefore, conventionally, chemical sterilization methods such as immersion in hydrogen peroxide (H,0, ) or sterilization with ethylene oxide, and physical sterilization methods such as irradiation with gamma rays and ultraviolet rays, have been used. Ta.

However, these methods have numerous drawbacks, and in recent years, a sterilization method using electron beam irradiation has been proposed and put into practical use as a method to eliminate these drawbacks. This is a method of sterilizing packaging materials by emitting high-energy electron beams accelerated through an electron beam-transmitting window into the atmosphere and irradiating them onto packaging materials.It is a complete dry sterilization method and does not require the use of radioactive substances. It is easy to install in-line and handle, and if the energy of the electron beam is increased, considerable penetration power can be obtained, so it has extremely excellent properties as a method of sterilizing packaging materials for food and beverages, and is widely used. However, from a practical point of view, there is a limit to the increase in accelerating voltage, and therefore there is a limit to increasing the energy of the electron beam, so the penetrating power of the electron beam is comparable to that of γ. Therefore, such electron beam sterilizers have had the problem of being limited to long strip packaging materials. Packaging materials such as long strips of paper and plastic films are
It is designed so that it can be handled as a roll wrapped around a suitcase, suitable material, core material, etc., and when processing such as processing, it can be transported by itself by unwinding the roll one by one and pulling out the packaging material. Since the packaging material is transported as part of the mechanism, it is possible to sterilize not only the surface and the insect surface but also the inside of the packaging material in-line by simply pulling it out from the roll while passing through the electron irradiation section. Although it is possible to simultaneously sterilize stacked packaging materials in-line by using high-energy electron beams within a practical range, it is possible to simultaneously sterilize stacked packaging materials in-line. Comparison of carton base paper used as the base for beverage cartons (material paper cut into a predetermined shape from raw material paper, or material prepared so that it becomes a cylinder immediately after being attached to the body and inflated) In the case of packaging material that is divided into small pieces,
5K itself, such as an IJ-shaped packaging material, cannot be used as a part of the conveyance mechanism. Therefore, in the past, the packaging material was held by gripping it with claws, or by being held in a holding frame. It will be transported from K such as a chain conveyor and sterilized.5
Therefore, in principle, complete sterilization is possible, but from a practical standpoint, sterilization of the transport mechanism and killing of the parts where the packaging material is in contact with the transport mechanism K tends to be incomplete, and sterilization is difficult. The effect cannot be expected to be sufficient.

Therefore, the conventional electron beam sterilizer has the drawback that it is difficult to obtain a device that can be expected to have a sufficient sterilizing effect on divided thin plate-shaped packaging materials.

In addition, equipment that uses a large amount of high-energy electron beams, such as electron beam killing equipment, generates a large amount of radiation such as Objects are irradiated with an electron beam indoors, and a labyrinth made of shimmering material K is set up at the entrance and exit of the object to expose the object to an X-ray beam outside.
However, if such a labyrinth is provided, and the object to be irradiated is in the form of a sheet, even if there is a maze, it will be difficult to carry the object into the irradiation chamber. However, if the object to be irradiated is a thin plate-like object such as a carton, and it is held one by one with an appropriate device as in the prior art described above, the structure of the labyrinth, The mechanism for conveying the material through it becomes extremely complicated, which inevitably results in a considerable increase in cost, and there is a risk that sufficient shielding effect cannot be expected.

The purpose of the present invention is to eliminate the above-mentioned drawbacks of the prior art, to be able to provide a sufficient killing effect even to relatively small thin plate-like objects such as cartons, and to have a simple structure and a shielding effect against radiation. An object of the present invention is to provide an electron beam sterilizer that can sufficiently obtain the following effects.

In order to achieve this object, the present invention arranges a plurality of pairs of conveying rollers each consisting of two rollers in a straight line, and uses these pairs of conveying rollers to move a thin plate-like object while also providing a radiation shielding function. The percentage point is the point at which it is possible to

An example of the electron beam sterilizer according to the present invention is shown below in FIG. 11i.
I will explain about iK.

FIG. 1 is a side view of an entire apparatus according to an embodiment of the present invention, partially shown through perspective K, in which 1 is an electron beam irradiation device (hereinafter referred to as EB device), 2 is an electron beam (EB) transmission window, and 3 is a gB irradiation chamber, 4 is a pair of transport rollers, 5 is a carton magazine, 6 is a carton stripper, 7 and 8 are carton strippers, 9 is a carton printer, 10 is a conveyor, 11 is a packaging film, and 12 is a film The sealer 13 is a conveyor for carrying out.

Incidentally, a"-a. indicates a carton undergoing agronomic treatment, and 4a and 4b indicate a holding roller and a driving roller of the conveying roller pair 4.

The EB device 1 is equipped with a high-voltage power supply, generates high-energy EB, and transmits the EB through an EB transmission window 2 made of a thin film such as titanium.
K radiation is emitted in the irradiation chamber 3.

The transport roller pair 4 includes a driving roller 4b which is rotationally driven by a driving motor (not shown), and a holding roller 4 which is in contact with the driving roller 4b from above with a predetermined pressing force! . of these rollers 4a, 4b.・It works by sandwiching the carton between 4 and transporting it in the direction of the arrow in the figure. As is clear from the figure, these plurality of conveyor roller pairs 4
The cartons are arranged so that the transport direction of the cartons passes through the center of the EB irradiation chamber 3 and forms a line on both sides thereof.

carton} The IJ picker 6 has a suction device on it,
It moves up and down between the upper position shown by the broken line, and serves to eject the cartons stacked in the carton magazine 1 and extract them from the lowest one.

Therefore, the cartons in Carton Magazine 5 are as follows:
After being taken out as carton a by the carton stripper 6, it is inserted between the leftmost rollers 4i and 4b of the pair of conveying rollers 4 by the pusher 7, and then passed between the pair of conveying rollers 4 as shown by the arrow. Direction K carton a, ~a
It is transported as shown in 4. And carton a,
As shown in the figure, when passing through the EB irradiation chamber 3, sterilization is performed by receiving high-energy gB irradiation from the EB device 1.

The RII-completed carton is discharged from the rightmost conveyor roller pair 4 onto the carton lifter 9 (indicated by the broken line), and after rising to the position shown in the figure, is pushed by the pusher 8 in the direction of the arrow [ They are transferred from the conveyor 10 to the sealer 12, wrapped in a predetermined number of sheets each with 1 liter of packaging film, and then conveyed out by the conveyor 13.

Next, FIG. 2 is an enlarged view of the main parts of this embodiment, in which 20 is the EB irradiation section, 21 is the supply side conveyance chamber, and 22 is the discharge side conveyance chamber. , 23 are made of a radiation shielding material such as lead, and the transport chambers 21 .
22 is a wall member, 24 is a single air outlet for cooling the EB transmission window 2, 25 is an air discharge passage, 26 is a cooling water pipe, and 23a. 23b is the wall member 23
The inner wall surfaces 23c and 23d are recesses provided in the inner wall surface of the wall member 23 to accommodate the rollers 4a and 4b. In addition, BB equipment 1l1, EB transmission window 2. EB irradiation room 3. The transport roller pair 4, holding roller 4m, drive roller 4b, cartons a, to a4, etc. are the same as in FIG.

The rollers 4a and 4b constituting the conveyance roller pair 4 are installed so as to be located in the recesses 23c and 23d formed in the fuzzy member 23, and the upper holding roller 4a is used to hold the cartons 1, . When A4 is inserted and when it is not, it moves up and down K as shown by the broken line,
When cartons 1 to a4 are inserted, K moves from the lower drive p-24b to carton a? as shown in FIG. It is separated by the thickness of ~A4, but the carton A1~Otori. is caught [
When not in use, the upper holding roller 4 as shown in FIG.
a is in complete contact with the lower drive row 24b, and there is l between them.
It is a trap to prevent Ir4 from occurring. Furthermore, these third
2 and 4 are views of the conveyance channel {21 or 22 in FIG. It turns on and off in response to the upward and downward movements of 4a.

From the air outlet 24, f is supplied by a pre-filter etc.
Illuminated air is introduced into the EB irradiation chamber 3, thereby cooling the EB transmission window 2 to prevent the function of the EB@position 10 from deteriorating. The free air blown into the gB irradiation chamber 3 cools the gB transmission window 2 and then flows into the transport chambers 21 and 22. It works to maintain a pressure slightly higher than atmospheric pressure, also known as positive pressure. Note that the positive pressure in K# in the transport chambers 21 and 22 at this time is controlled by the air exhaust passage 25.

It goes without saying that the inside of the device needs to be pre-sterilized before use, but in this case, it is especially necessary to pre-sterilize the inside of the a-feeding chamber 21 and maintain its positive pressure. It's not a translation. That is, since unprocessed cartons are carried into the transfer chamber 2l, even if positive pressure K is maintained, the arm will enter together with these cartons, and these #a1 etc. are EB irradiation room 3
This is probably because the transport chamber 22 is completely sterilized by the EB irradiation chamber 3, and the cooling water pipe 26 is completely shielded from the transport chamber 21 by the gB irradiation inside the EB irradiation chamber 3.
This is for cooling the wall surface that gB hits in the B irradiation chamber 3, and serves to prevent damage to the carton due to temperature rise.

Therefore, as explained in FIG. 1, if the cartons are sequentially fed into the transport chamber 21 at predetermined time intervals, the fed cartons A, A, A, (A4, etc.) are sequentially moved to the right side 1 - The high-energy E
Complete sterilization is achieved by exposure to B radiation. At this time, in the EB irradiation chamber 3, the carton a is sent out from the pair of conveying rollers 4 on the left side, and is fed from its tip to the pair of conveying rollers 4 on the right side while sequentially receiving EB irradiation on its surface. Therefore, in the areas where EB is irradiated, there are no E
There are no members that cast shadows on B, and therefore,
Irradiation with gB enables complete treatment of useful bacteria.
Due to the irradiation unit 20, various radiations such as X-rays are generated in the EB irradiation chamber 3. In other words, the basic property of high-energy particle beams such as EB is that [when they interact with matter, they cause not only separation loss, but also radiation loss due to the bremsstrahlung of the particles themselves, which causes a large amount of radiation loss. This is because it generates a lot of radiation. The spectrum of radiation emitted at this time extends from X-rays to the rIs region and is extremely harmful, so sufficient shielding is required.

For this purpose, it is sufficient to install a hardening material such as lead or concrete, but in such an EB office equipment, the object to be sterilized, such as a cart y, is carried into the EB irradiation chamber and taken out. Since a passage is required, it is difficult to provide sufficient shielding in this area, and it is also difficult to transport the objects to be killed.
However, in the above embodiment, the direction of movement of the carton is in a straight line so that all
Since the pair of feed rollers 4 are arranged, the cartons are conveyed extremely smoothly, and there is no need for any claws or holding frames for feeding. On the other hand, each roller 4m configuring these conveyance roller pair 4. 4b and the lower side are the recesses 23c of the wall member 23. 23d, and among these, the upper holding roller 4a is in close contact with the lower driving roller 24bK when the carton is not sandwiched between these rollers. All radiation such as X-rays that have entered the chambers 21 and 22 are suppressed by the pair of transport rollers 4.
There is no risk of leakage from the carton supply side to the carton discharge side. That is, as already explained, since the operation of feeding cartons into the conveying cha/pa 2l is performed sequentially at predetermined time intervals, as shown in FIG. fa1 and FIG. , in the transport chamber 21.22 containing the EB irradiation chamber 3, the cartons are located a predetermined distance apart, as shown by 3, to a4. Therefore, in the transport chambers 21 and 22, there are always a number of transport roller pairs 4 that do not sandwich a carton.
Since these rollers 4a and 4b are in close contact with each other, it is possible to completely prevent radiation from the EB irradiation device 3 from leaking out between the rollers 4a and 4b.

Further, although there are considerable gaps between the rollers 4a, 4b and the depressions 23C, 23d, these gaps are not in a straight line with respect to the direction of radiation leakage;
The surface of rollers 4a and 4b will have a shaved shape, so radiation such as XII that has entered this area will be absorbed by rollers 4a and 4b.
Reflection and refraction are repeated multiple times between the surface of b and the surface of the wall member 23, and the strength is significantly reduced due to large attenuation, so that practically no leakage occurs.

Therefore, according to the above embodiment, the conveyance path of a thin plate-shaped object such as a carton is -l]! Even though it is made linear so that it can be conveyed sufficiently smoothly and reliably, it is almost completely protected against radiation such as X@.

By the way, in this type of EBf/94 device, the EB irradiation section and the area for transporting and discharging the objects to be sterilized are strictly shielded, so the objects to be sterilized cannot be transported in this area. It is difficult to monitor the status, and for this purpose, it is necessary to provide a viewing window made of radiation-shielding glass or use an industrial television camera, which tends to increase costs.

However, according to the above embodiment, fI! sending champa 21
．． 22 and the transport state of the carton in the EB irradiation chamber 3 can be easily monitored.

In FIGS. 3 and 4, 27 is a limit switch for detecting the vertical position of the shaft of the upper holding roller 24a, and as shown in FIG. When the carton is sandwiched and the shaft of the holding roller 4a moves in the direction of the arrow, and as shown in FIG. κ operation is performed so that the contact switching state differs depending on the direction of movement.

Therefore, if this limit switch 27 is provided on all or some of the conveying roller pairs 4, the presence of a carton in the conveying chamber 21 and 22 including the EB irradiation chamber 3 will be detected by the contact switching state K of the limit switch 27. Its location can be known and its movements can be monitored.

For example, when the limit switch 27 is in the state shown in FIG.
If an indicator lamp is provided that lights up when 70 is turned on, the location of the carton can be known from the lighting of the indicator lamp K.

In addition, in this type of EBfi bacterium device, the inside of the transfer chamber including the EB irradiation chamber is maintained at a pressure significantly higher than atmospheric pressure, so-called positive pressure K! It is necessary to prevent IAm from entering, and therefore it is necessary to send air sterilized by a pre-filter etc. into the EB irradiation chamber and keep it flowing into the transfer chamber. The garden air outlet 24 is EB
A peripheral area K of the transmission window 20 is provided, and the air KK blown through the window cools the EB transmission element 2 to reduce the EB transmission 'I8.
In addition to preventing the rise of 2 and avoiding the Isono low-pressure of EBmut, the upper pressure is also maintained by this black a2 ki, so 41 becomes simpler and costs can be easily reduced.

Furthermore, according to these four embodiments, the transport chambers 21, 22
Since the lines are straight and there is no labyrinth, the internal volume of these is relatively small, and this reduces the amount of inflow of air required to maintain the positive pressure mentioned above. This has the effect of requiring less energy for operation.

As explained above, according to the present invention, a thin plate-like object such as a carton cannot be held by a claw or a holding frame.
In addition to making B-killing possible, there is no need for a labyrinth for radiation protection, so the drawbacks of conventional technology are eliminated, the sterilization effect is complete, and the configuration is simple, operation monitoring is easy, and energy saving is achieved. It is possible to provide an EB arousal device that is useful for reducing the amount of EB at a low cost.

[Brief explanation of the drawing]

Fig. 1 is a side view of an embodiment of the electron beam sterilizer according to the present invention, partially shown through perspective K, Fig. 2 is a partially enlarged front view, and Figs. 3 and 4 show conveyor rollers. It is an explanatory diagram of a pair of operations. 1... Electron beam irradiation device (gB device), 2...
...Electron beam transmission window, 3...Electron beam irradiation room, 4
......2 pairs of conveyor rows, 4m...Holding roller, 4b...Driving roller, 21.22...
...Transportation chamber, 23...Wall member, 23m,
23b-...Inner wall surface, 23c, 23d-...
Bebomi, 24... Sterile air outlet. -215-

Claims (1)

[Claims] (1) In an electronic casserolysis device κ that sterilizes thin plate-like objects by sequentially irradiating them with electron beams one by one while transporting them, a thin plate-like object is held in between and moved in a direction parallel to the surface of the object. A plurality of pairs of conveyance rollers each consisting of two rollers were arranged so that the direction of movement of the object by them was in a straight line, and they were arranged and housed on both sides of the electron beam irradiation section at a predetermined interval. The electronic satan. (In claim 1, the above-mentioned conveyor
An electron beam sterilizer characterized in that a radiation wrapper wall is provided in the inner wall of the chamber and has a recessed portion for accommodating at least a portion of each rod of the plurality of pairs of conveying rollers. (i) In claim 1 or 2, there is provided a means for holding one roller of the plurality of two pairs of conveying rollers so as to be movable in a direction away from the other roller; An electron beam sterilizer characterized in that it is provided with means for elastically pressing the roller.
In this case, a non-air blowing section is provided around the electron beam emitting port provided in the electron beam irradiation section to cool the electron beam emitting port and maintain positive pressure in the killing device. An electronic sterilizing device characterized by having the following structure: In claim 3, the electronic sterilizing device is characterized in that it is provided with means for detecting the movement of one of the rollers, and is configured to enable monitoring of the sterilizing operation. Electron beam killing device 1.