JPS6058666B2 - Electron beam sterilizer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electron beam sterilizer suitable for sterilizing cups made of paper, plastic, etc.

An electron beam sterilizer is a device that sterilizes objects by irradiating them with high-energy electron beams accelerated by high voltage.
It is an extremely preferred method for sterilizing food containers such as plastic cups, and has become widely adopted in recent years.

By the way, the electron beam generator (hereinafter referred to as EB device) used in such sterilization equipment is generally equipped with an electron gun and a scanning device, and scans and fires an electron beam accelerated with high voltage. Although the resulting electron beam has strong directionality, it does not have the strong penetrating ability of gamma rays, so it is not suitable for objects with complex shapes such as cup-shaped objects that have deep concave parts. Irradiation from only one direction may result in incomplete sterilization of some parts. Therefore, in conventional electron beam sterilization equipment for cup-shaped objects, each cup-shaped object to be sterilized is held one by one using an appropriate device, and the electron beam is irradiated while changing the posture of the object in various directions. As a result, the mechanism is complicated and tends to increase in size, and the cost of the device increases significantly.In addition, there is a drawback that the part holding the cup-shaped object tends to be insufficiently sterilized.

In addition, equipment that uses a large amount of high-energy electron beams, such as an electron beam sterilizer, generates a large amount of radiation such as X-rays, so in such equipment, the irradiation chamber must be shielded. The object is irradiated with an electron beam, and a labyrinth made of shimmering material is installed at the entrance and exit of the object to expose the object to an X-ray beam.
Methods are widely used to prevent wires from leaking.

However, when such a maze is provided, if the object is in the form of a sheet, it is extremely easy to carry the object into and out of the irradiation chamber even if there is a maze; If these knob-like objects are held one by one using an appropriate device as in the prior art described above, the structure of the labyrinth and the mechanism for transporting it through it will become extremely complex, resulting in considerable cost. In addition to the inevitable increase in
There was a drawback that there was a risk that the healing effect would not be sufficient or that the healing effect could not be expected. An object of the present invention is to eliminate the above-mentioned drawbacks of the prior art, to easily transport a cup-shaped object while changing its posture with a simple configuration, and to provide a method for transporting the cup-shaped object at the entrance and exit of the irradiation chamber. To provide an electron beam sterilizer that can reliably perform sterilization with a simple configuration.

In order to achieve this objective, the present invention provides a spiral guide rail vertically in the electron beam irradiation chamber, and a cup-shaped object to be irradiated rolls on this guide rail due to gravity. while the vehicle is being transported;
A feature of this device is that it makes it possible to irradiate the entire surface of the cup-shaped object with an electron beam by utilizing changes in its posture as it rolls on the guide rod.

Embodiments of the electron beam sterilizer according to the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing one embodiment of the present invention, in which 1 is an electron beam emission window of an electron beam generator, 2 is a vertical spiral guide rail, 3 is an outer wall made of a radiation-resistant material such as lead, 4 is a cup supply port, 5 is a cup discharge port, 6-1 to 6-3
is a partition wall, and 7 is a stopper.

Further, A represents the entire electron beam irradiation chamber formed by the outer wall 3, B represents the effective irradiation range of the electron beam emitted from the electron beam radiation window 1, and C1 to C4 represent the irradiation area. The cups are shown in different positions in chamber A. Fig. 2 is a top view showing details of the vertical spiral guide rail (hereinafter simply referred to as GR) 2, and also shows a part of the outer wall 3 forming the electron beam irradiation chamber A, and in the figure 8 is the electron beam generator. The device (EB device) is shown in which 2a represents an inclined straight part of GR2, and 2b represents a half inside of GR2.

Note that C5 to C7 represent cups. Figure 3 is a partially detailed view seen from the direction of the arrow x in Figure 2, Figure 4 is a detailed view similarly seen from the direction of the arrow Y in Figure 2, and Figure 5 is a detailed view along Z-Z of Figure 2. FIG.

The EB device 8 emits an electron beam E from the radiation window 1 as shown in FIG.
A region including most of the inclined straight portion 2a of GR2 is irradiated with an electron beam EB.

The entire GR2 is made in a vertical spiral shape so that the cup C carried in from the supply port 4 rolls on top of it due to gravity and reaches the top of the discharge port 5. Therefore, in FIG. Although it is shown as a straight line, as is particularly clear from FIG. 5, in the inclined straight part 2a, the outer side of the spiral shape is formed low to match the taper of the cup C, and the cup C does not come off from the GR2. It is made to have a gutter-shaped cross section with guide walls 2c and 2d on both sides, and is given a predetermined inclination in the length direction.

As shown in FIG. 2, the end portions of the inclined straight portions 2a are connected to each other in a semi-inner portion 2b to form a vertical spiral GR. At this time, the center radius of the semi-inner part 2b is made to match the radius of the circular trajectory drawn when the tapered cup C is rolled on a flat surface, so that the cup C can roll smoothly in the semi-inner part 2b. There is. Next, FIG. 6 shows an embodiment of the cup supply device, where 9 is a passage communicating with the cup supply port 4, and 10 is a stack of cups C, which are held in a stack, and one by one is intermittently inserted into the passage 9. This is a cup holding and feeding machine for dropping.

Note that the passage 9 is formed by an outer wall 3 made of a flexible material such as lead, and the outlet at the lower end thereof constitutes the supply port 4.

Next, the operation will be explained.

First, the EB device 8 is operated to irradiate the electron beam EB into the irradiation chamber A from the electron beam emission window 1.

Although not specifically explained, this EB device 8 has a scanning device in addition to the electron gun, and scans the electron beam up and down along the vertically elongated electron beam emission window 1 as shown in FIG. At the same time, by utilizing the lateral spread of the electron beam EB shown in FIG. 2, it has a considerably wide effective irradiation range B (FIG. 1). Next, cup holding and feeding machine 1
0 is activated, and the stacked cups C (FIG. 6) are successively and intermittently dropped one by one into the passage 9 at predetermined time intervals.

As a result, the dropped cup C-1 slides down the passage 9, and the cup C-1 is sent into the irradiation chamber A from the supply port 4.
The upper end of R2 is reached. This state is called cup C. Indicated by
At this time, the cup C is moved by the stopper 7 provided on GR2. prevent it from coming off from GR2 and flying out. Now, as is clear from FIG. 6, the cup CO thus brought to the upper end of GR2 forms a spiral GR2.
The opening is facing the outside of 2, and that is the GR.
It begins to roll due to the inclination of the straight portion 2a of No. 2, and passes through the effective irradiation range B of the electron beam EB while rolling like the cup C1 in FIG.

At this time, as is clear from FIG. 2, the opening of the cup C1 is facing the electron beam emission window 1 of the E detector 8, and moreover, it is rolling in a direction almost perpendicular to the direction of arrival of the electron beam EB. Since the electron beam EB moves to , the inside of the cup C1 is fully irradiated with the electron beam EB.

At this time, since the cup C1 has a tapered outer shape, it tries to change its course when rolling down the straight section 2a, and the guide walls 2c, 2d of the straight section 2a (Fig. 5)
By appropriately determining the slope of the straight portion 2a and the clearance between the guide walls 2c and 2d, the speed at which the cup C1 rolls down the straight portion 2a can be kept at a predetermined, almost constant speed. can be kept. The cup C1, which has thus passed through the part included in the effective irradiation range B of the straight part 2a, reaches the semi-interior 2b of the GR2 at the position of the cup Q in FIG. 2, and rolls smoothly as shown by the cups C6 and C7. However, it passes through this semi-interior 2b, changes direction by 180 degrees, and enters the next straight section 2a. Then, as shown by cup C8, it rolls down this straight section 2a while being irradiated with the electron beam EB from the rear side, and as a result, the outside of the cup is also completely irradiated with the electron beam. This is repeated for the number of straight parts 2a, that is, in this embodiment, four times as shown in FIG.
The electron beam is irradiated twice from the inside of the cup and twice from the outside, moving from cup C1 to C2 and then C3 in Figure 2, and finally detaching from GR2 at the lower end of GR2 as shown by cup C4. , it falls through the discharge port 5, is transferred to a conveyor, and is transported to an aseptic filling room or the like for subsequent use. Therefore, according to this embodiment, since there is no means such as a claw for holding a specific part of the cup, there is no part that is not irradiated with the electron beam EB, and moreover, there is no part that is not irradiated with the electron beam EB. The irradiation is carried out evenly and thoroughly, making it possible to obtain a complete sterilizing effect. Further, according to this embodiment, the portion from the supply port 4 to the external cup holding and supplying device 10 is a curved passage 9 surrounded by an outer wall 3 made of a flexible material, as shown in FIG. , sufficient attenuation is provided to radiation such as X-rays that is about to leak to the outside from the irradiation chamber A through the supply port 4, and therefore, the risk of radiation leakage can be eliminated. .

Although not shown, if the discharge port 5 is similarly curved, leakage of radiation can be easily and reliably prevented. By the way, in the above embodiment, as shown in FIGS. 1 and 2, partition walls 6-1 to 6-3 are provided in the electron beam irradiation chamber A.

These partition walls 6-1 to 6-3 are made of a radiation-resistant material such as lead, like the outer wall 3, and are made of a spiral GR2.
They are formed by being inserted alternately from the left and right into the gap between the spirals, and each tip reaches the effective electron beam irradiation range B as shown in FIG. Therefore, in this embodiment, during operation, the high-energy electron beam EB existing within the partition walls 6-1 to 6-3 and the effective irradiation range B is
, the inside of the electron beam irradiation chamber A is sequentially divided into five independent chambers 4 to (
As a result, the degree of sterility of the cup conveyance path increases as it approaches from the supply port 4 to the discharge port 5. It can provide excellent sterilizing effects.

By the way, in the above embodiment, as is clear from FIG. 1, all of the straight portions 2a of the vertical spiral GR2 are included in the effective irradiation range B.

However, as another embodiment of the invention, this GR2
may be extended upward beyond the effective irradiation range B, and the number of partition walls 6-1 may be increased accordingly.

According to this, a plurality of partition walls 6-1 are also present in the path for radiation such as X-rays generated by electron beam irradiation within the effective irradiation range B to reach the supply port 4. Since a labyrinth is thus formed, it is possible to almost eliminate radiation leaking from the supply port 4, so that the configuration for sequentially supplying cups to be sterilized from the supply port 4 can be simplified. In addition, an extension part of this GR2 is also provided in the lower part, and the partition wall 61 is installed accordingly. It goes without saying that if the discharge row 5 is provided further below, almost no radiation leaks from the discharge row 5. Note that the vertical spiral guide rail is also an elliptical GR2 consisting of a straight portion 2a and a semi-inner portion 2b as in the above embodiment.
It is not necessary to use a circular vertical or straight spiral guide rail.

In addition, this vertical spiral guide rail is made of two instead of one.
It is also possible to further increase the number of cups to be simultaneously irradiated with electron beams by providing them in the electron beam irradiation chamber at appropriate intervals.

As explained above, according to the present invention, since the cup-shaped object to be sterilized is sequentially irradiated with electron beams while being rolled on the vertical spiral guide rail, the cup-shaped object to be sterilized is Sufficient sterilization treatment is performed on the entire surface of the sterilized object, and it is easy to carry the cup-shaped object into and out of the electron beam irradiation chamber. Since the separation is carried out in a sterile atmosphere through radiation irradiation, a sufficient sterilizing effect can be obtained against bacteria that enter the atmosphere. It is possible to obtain an excellent sterilizing effect, reduce costs, and provide an electron beam sterilizer with a knob-shaped object.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing an embodiment of the electron beam sterilizer according to the present invention, FIG. 2 is a top view of the guide rail, FIG. 4 is a detailed view similarly seen from the direction of arrow Y, FIG. 5 is a sectional view taken along the Z-Z line, and FIG. 6 is a sectional view showing one embodiment of the cup feeding device. 1... Electron beam emission window, 2... Vertical spiral guide rail, 3... Outer wall, 4...
・Cup supply port, 5...Cup discharge port, 6-1~
6-3... Bulkhead, 7... Stopper, 8...
...Electron beam generator, 9...Passway, 10.
...Cup holding and feeding machine, A...Electron beam irradiation window, B...Effective electron beam irradiation range, C...
··cup.

Claims (1)

[Scope of Claims] 1. A device for sterilizing cup-shaped objects by electron beam irradiation, comprising: a vertical spiral guide rail for transporting the cup-shaped object by gravity while rolling; and an electron beam housing the spiral guide rail; A beam irradiation chamber and an electron beam source for irradiating an electron beam from the lateral direction of the spiral guide rail in the electron beam irradiation chamber are provided, and a cup to be sterilized is provided at the upper end of the spiral guide rail. 1. An electron beam sterilizer characterized by being configured to obtain a sterilized cup-shaped object from its lower end by sequentially and intermittently supplying the cup-shaped object. 2. In claim 1, a plurality of partition walls are provided in the gap between each spiral portion of the vertical spiral guide rail, the partition walls being inserted alternately on the left and right from a direction substantially perpendicular to the direction of electron beam irradiation by the electron beam source. An electron beam sterilization apparatus characterized in that the interior of the electron beam irradiation chamber is divided into a plurality of sections by the plurality of partition walls and the electron beam from the electron beam source. 3. In claim 1 or 2, the vertical spiral guide rail is formed into an elliptical shape having a straight line portion substantially parallel to the lateral direction, and the above-mentioned vertical spiral guide rail is formed in an elliptical shape having a straight line portion substantially parallel to the lateral direction, and An electron beam sterilizer characterized in that it is configured to be irradiated with an electron beam from an electron beam source. 4. In any one of claims 1 to 3, the vertical spiral guide rail extends in at least one of the vertical directions beyond the effective electron beam irradiation range by the electron beam source, and The plurality of partition walls present in a portion extending in at least one direction form a labyrinth for radiation leaking from at least one of a supply port and a discharge port of the cup-shaped object to the guide rail. An electron beam sterilizer characterized by: