JP2019085142A - Flash pulse disinfection processing system for containers - Google Patents

Abstract

To provide a flash pulse disinfection processing system for containers that reduces uneven radiation caused by shapes of irradiation objects and maintains the disinfection processing speed for irradiation objects as well as achieving a high disinfection effect without increasing the lamp output.SOLUTION: The flash pulse disinfection processing system includes: a conveyer 12 for conveying containers to which a disinfection process is applied in one direction (X direction); and a plurality of irradiation devices 6a, each of which includes one lamp 2 for projecting ultraviolet ray pulses above the conveyer (in a Z direction). The lamps are arranged such that the directions of axial lines (Y direction) of the lamps are orthogonal to the traveling direction (X direction) of the containers and the light emission from the plurality of irradiation devices has a different focal length for each irradiation device. When the containers are conveyed directly under the lamp provided in each irradiation device, the conveyer stops and the lamp projects ultraviolet ray pulses. The projection of ultraviolet ray pluses is repeated for each irradiation device.SELECTED DRAWING: Figure 2A

Description

  The present invention relates to a flash pulse sterilization system for containers. More specifically, the present invention relates to a sterilization treatment system for food containers and the like using, for example, a xenon flash lamp.

  It is important for food manufacturing and processing manufacturers to sterilize food containers reliably. With the diversification of consumer needs, reliable sterilization of food containers is required due to food chlorination, elimination of preservatives, and extension of shelf life.

  At present, in place of heat treatment and sterilization by drugs, development of sterilization technology capable of non-heating and non-contact sterilization is in progress. As such non-heating / non-contact sterilization technology, flash pulse sterilization has attracted attention.

  Xenon flash lamps are typically used in flash pulse sterilization systems. The light emission of the xenon flash lamp is rich in ultraviolet light with a wavelength of 200 to 300 nm that is effective for sterilization.

  The germicidal treatment system using flash light pulse has strong bactericidal effect, easy pulse control of light emission, no residue is generated because it is non-contact, and it is applied to the germicidal treatment target for extremely short time pulse irradiation. It has advantages and features such as less influence.

  As prior art documents, the following documents exist regarding a sterilization treatment system using a xenon flash lamp for food containers.

Japanese Patent Application Laid-Open No. 2015-134311 "Irradiator" (publication date: 2015.7.27) Applicant: Iwasaki Electric Co. JP-A-2015-157646 "Sterilization processing system for container" (release date: 2015.9.3) Applicant: Iwasaki Electric Co., Ltd. Japanese Patent Application Laid-Open No. 2015-182792 "Sterilization processing system for container" (release date: 2015.10.22) Applicant: Iwasaki Electric Co., Ltd.

  While the flash pulse sterilization processing system has the above advantages and features, there is a problem that only the portion irradiated with the light to be sterilized is sterilized. There are many vertical solid shapes such as cup containers in food containers to be sterilized, and the higher the height, the more difficult it is to uniformly irradiate the light of the flash lamp. If there are parts that are not irradiated, parts that are weak in irradiation, etc., and the irradiation unevenness increases, a sufficient sterilizing effect can not be obtained.

  In addition, if the number of irradiations is increased needlessly or the emission intensity is increased, the power consumption is increased and the life of the xenon flash lamp is shortened. On the other hand, if the irradiation time to the food container is prolonged, the time required for the sterilization treatment will be long and the workability will be poor.

  Therefore, the present invention reduces the irradiation unevenness caused by the shape of the irradiation target, maintains the sterilization processing speed of the irradiation target, and further achieves a high sterilization effect without increasing the lamp output. It aims to provide a system.

  The sterilization treatment system for food containers according to the present invention is a flash pulse sterilization treatment system for containers, wherein the conveyor for conveying the container to be sterilized in one direction (X direction), and above the conveyor (Z direction) And a plurality of irradiators each having one lamp for pulse irradiation with ultraviolet light, wherein the lamp axis direction (Y direction) is orthogonal to the traveling direction (X direction) of the container The light emitted from the plurality of irradiators has different focal lengths, and the conveyor stops when the container is conveyed directly below the lamps provided for each irradiator. The lamp is irradiated with an ultraviolet pulse, and the ultraviolet pulse irradiation is sequentially repeated for each irradiator.

  Furthermore, the sterilization treatment system for food containers according to the present invention is a flash pulse sterilization treatment system for containers, comprising: a conveyor for conveying a container to be sterilized in one direction (X direction); And one irradiator equipped with a plurality of lamps for pulse irradiation of ultraviolet light), the lamp axis direction (Y direction) of lamp axis is orthogonal to the traveling direction (X direction) of the container And the light emission from the plurality of lamps has different focal lengths, and the conveyor is stopped when the container is transported directly under each of the lamps provided in the irradiator. The lamp is irradiated with an ultraviolet pulse, and the ultraviolet pulse irradiation is sequentially repeated for each lamp.

  Furthermore, in the above-mentioned sterilization treatment system, the plurality of lamps may be replaced with a relatively small number of U-shaped lamps or rectangular lamps.

  Furthermore, in the sterilization treatment system for the food container, the distance between adjacent lamps or the distance of the portions of the adjacent lamps extending in the Y direction is determined in relation to the distance L between the adjacent containers in the X direction. It is also good.

  Furthermore, in the sterilization treatment system for the food container, the lamp may be a pulsed xenon lamp.

  Furthermore, in the sterilizing system for food containers, a plurality of the containers may be juxtaposed in the width direction (Y direction) of the conveyor, and may be simultaneously sterilized.

  According to the present invention, it is possible to reduce the irradiation unevenness caused by the shape of the irradiation object, maintain the sterilization processing speed of the irradiation object, and obtain the high sterilization effect without increasing the lamp output, flash pulse sterilization processing for the container We can provide a system.

FIG. 1A is a view for explaining the outline of the conventional food container sterilization processing system. FIG. 1B is a cross-sectional view of the YZ plane through the lamp axis of the sterilization processing system shown in FIG. 1A. FIG. 1C is a view for explaining the sterilization treatment process of the sterilization treatment system shown in FIG. 1A. FIG. 2A is a view for explaining the general outline of the food container sterilization processing system according to the first embodiment. FIG. 2B is a cross-sectional view of the YZ plane through the lamp axis of the sterilization system shown in FIG. 2A. FIG. 2C is a view for explaining a situation where the container is irradiated by each irradiator of the sterilization processing system shown in FIG. 2A. FIG. 3A is a view for explaining the general outline of the food container sterilization processing system according to the second embodiment. FIG. 3B is a cross-sectional view of the YZ plane through the lamp axis of the sterilization system shown in FIG. 3A. FIG. 4 illustrates the lamp used in the sterilization treatment system according to the third embodiment.

  Hereinafter, an embodiment of a flash pulse sterilization treatment system for a container according to the present invention will be described in detail with reference to the attached drawings. Here, as a flash pulse sterilization processing system for containers, a sterilization processing system using a xenon flash lamp for food containers will be described as an example. In the drawings, the same reference numerals are given to the same elements and duplicate explanations are omitted.

[Conventional sterilization system]
In order to facilitate the understanding of the sterilization system according to the present embodiment, first, a conventional sterilization system will be described. FIG. 1A is a diagram for explaining the general outline of a conventional food container sterilization processing system 100. The containers 8 to be sterilized are placed in line on the transport conveyor 12 and transported in the arrow direction. A plurality of containers 8 are aligned in the width direction of the transport conveyor 12 and positioned and loaded at intervals L in the traveling direction of the transport conveyor 12.

  An irradiator 6 a having a lamp 2 inside is provided above the transfer conveyor 12. Furthermore, a reflecting mirror 4 is provided inside the irradiator 6, and light emitted from the lamp 2 in the direction opposite to the container is reflected and directed to the container to achieve effective use of the light emission. The lamp 2 is in a plane parallel to the surface of the transfer conveyor 12, is positioned so that the lamp axis extends in the direction perpendicular to the moving direction, and uniformly irradiates the entire moving container. Here, in order to make it easy to understand the positional relationship of each element, the traveling direction (conveyor direction of the container) of the conveyor 12 is X direction, the axial direction of the lamp 2 is Y direction, perpendicular direction to the XY plane (container 8 is a lamp The direction of the lamp viewed from the container when it is directly below 2 is defined as the Z direction, which is displayed in each of the subsequent figures.

  Each element will be described. The container 8 is typically a food container. Food container lids are also included. In addition, it includes any container which requires sterilization treatment such as medicine taken into human body.

  The lamp 2 is typically a straight tube type xenon flash lamp. Flash pulse sterilization using a xenon flash lamp is also referred to as pulsed xenon sterilization.

  In the irradiator 6a, cooling ducts 7 are provided at both ends, and a cooling flow is circulated inside the irradiator 6a to cool the lamp 2.

  The mirror surface of the reflecting mirror 4 preferably forms a part of an elliptical shape from the viewpoint of effectively irradiating the inside of the container. The shape of this mirror surface determines the focal length f of the reflected light (and hence of the light emitted from the illuminator).

  A yogurt filling machine is an example of such a sterilization treatment system. The sterilization processing system of the yogurt filling machine is a tact conveyance which repeats stop and conveyance, and it is stop 0.75 second, movement 1.05 second, and movement distance 178 mm. Therefore, the transport speed is 170 mm / sec.

(Sterilization process)
FIG. 1C is a view for explaining the sterilization process of the conventional food container sterilization system 100. In the conventional food container sterilization processing system 100, when the container 8 loaded on the transfer conveyor 12 comes directly under the lamp 2 (stop time of time t = a), the transfer conveyor 12 is temporarily stopped, and the lamp 2 It is sterilized by ultraviolet light. After that, it restarts, moves by an interval L in the direction of the arrow, stops again, and sterilizes. That is, the transport conveyor 12 is stopped every time the space L is advanced, and the sterilization process is performed. The number of pulse emission is typically 6 pulses. The container 8 in which the sterilization process is finished proceeds to the food filling step of the next step.

  When the irradiation intensity distribution of the inner surface (irradiated surface) of the container 8 was measured, it was found that the irradiation intensity has strength. That is, it turned out that there are places (irregularities in illuminance distribution) where the irradiation intensity is relatively weak on the right side, left side and bottom of the inner surface of the container when viewed in the container cross-sectional view of FIG. 1C.

  In the sterilization processing system 100, the focal point of the ultraviolet light emission from the reflecting mirror is adjusted to be connected in the container so that the illuminance is high at the lower end portion of the side surface where the irradiation light hardly hits. As a result, it was found that the illuminance was low on the side surfaces other than the lower end portion of the inner surface of the container 8. The height of the illuminance is determined by the density of light emission.

  Furthermore, with regard to the left and right side surfaces, a decrease in illuminance may be considered because the incident angle of ultraviolet light is large. With respect to the bottom surface, although direct emission from the lamp 2 is directly incident, it is considered that the reflected emission from the reflecting mirror 4 is not sufficiently used because the lamp 2 interferes.

  Even with such a conventional sterilization treatment system 100, the viable count is at a level that can be regarded as zero, and there is no problem in the hygiene of the food container. However, hygiene management of food containers should be done with care.

The features of this conventional sterilization processing system 100 are as follows.
(1) Irradiate with one irradiator equipped with one lamp. The lamp is a straight pipe type.
(2) The traveling direction (X direction) of the container (and thus the conveyor) is orthogonal to the lamp axis (Y direction) when viewed in the Z direction.
(3) A plurality of containers are juxtaposed in the width direction (Y direction) of the conveyor and are simultaneously sterilized.
(4) One pulse of six pulses is applied to one container.

  The sterilization treatment system according to the present embodiment solves the problem of the intensity of the irradiation intensity (unevenness of the illuminance distribution) to enable more reliable sterilization treatment.

[Sterilization processing system according to the first embodiment]
The sterilization processing system 10 according to the first embodiment will be described focusing on differences as compared with the conventional sterilization processing system 100 with reference to FIGS. 2A to 2C.

  FIG. 2A is a view for explaining the general outline of the food container sterilization processing system 10 according to the first embodiment. The sterilization treatment system 10 is different from the sterilization treatment system 100 in that three irradiators 6a-1, 6a-2, 6a-3 are provided. Furthermore, the focal distances f1, f2, and f3 of the reflected lights from the reflecting mirrors 4-1, 4-2, and 3-4 provided in the respective irradiators are different from each other.

  FIG. 2B is a cross-sectional view of the Y-Z plane through the lamp axis of the sterilization treatment system 10. Since the cross sections of the three irradiators are drawn together, the reference numerals of the irradiators are 6a-1, 6a-2, 6a-3, and the reference numerals of the reflecting mirrors are 4-1, 4- Note that it is 2,4-3.

  Drawing 2C is a figure explaining the situation where the container is irradiated by each irradiator. Here, for example, the focal distance of the reflected light from the reflecting mirror is f1 <f2 <f3.

  FIG. 2C (A) shows a situation where the container is sterilized by the light emission of the irradiator 6a-1, and since the focal distance f1 of the reflecting mirror 4-1 is relatively short, centering on the upper side surface of the container inner surface It is strongly disinfected. FIG. 2C (B) shows a situation where the container is sterilized by the light emission of the irradiator 6a-2 and the focal distance f2 of the reflecting mirror 4-2 is an intermediate value, so the center side portion of the inner surface of the container is centered Is strongly sterilized. FIG. 2C (C) shows a situation where the container is sterilized by the light emission of the irradiator 6a-3, and since the focal distance f3 of the reflecting mirror 4-3 is relatively long, The center is strongly sterilized.

  As described above, the three-stage sterilization process solves the problem of the intensity of the irradiation (unevenness of the illuminance distribution), and a more reliable sterilization process can be performed. Note that the number of irradiators is three, and two or more irradiators can be provided as desired.

  In the sterilization treatment process, tact conveyance which repeats stop and conveyance is performed. In one example, the stop time is 1.2 seconds and the transport time is 0.8 seconds. Further, the pulse irradiation is 6 pulses, and the moving distance of the container is the shortest about 200 mm, and the conveying speed of the container is 200 mm / sec.

  By matching the distance between adjacent lamps to the distance L between adjacent containers in the X direction or by associating it with an integer multiple or the like, simultaneous irradiation from multiple lamps becomes possible, and the workability can be improved. It can.

  In the sterilization processing system 10 according to the first embodiment, the sterilization processing can be performed even with a short stop time by reducing the number of irradiations per one irradiator from conventional 6 pulses to 2 pulses. In fact, although the stop time required for the conventional 6 pulse irradiation is 1.2 seconds, only 2 pulses are required in the first embodiment, so the stop period can be 0.4 seconds, and the speed of the sterilization processing line can be increased. Is possible.

The features of this sterilization processing system 10 are as follows.
(1) Irradiate with a plurality of irradiators each equipped with one lamp. The lamp is a straight pipe type. The focal lengths of the light emission from each irradiator are different.
(2) The traveling direction (X direction) of the container (and thus the conveyor) is orthogonal to the lamp axis (Y direction) when viewed in the Z direction.
(3) A plurality of containers are juxtaposed in the width direction (Y direction) of the conveyor and are simultaneously sterilized.
(4) Since irradiation is performed a plurality of times with respect to one container, irradiation per one time is performed irradiation of relatively few pulses (for example, two pulses).

[Sterilization processing system according to the second embodiment]
A sterilization processing system 20 according to the second embodiment will be described focusing on differences as compared with the sterilization processing system 10 according to the first embodiment, with reference to FIGS. 3A to 3B.

  FIG. 3A is a view for explaining the general outline of the food container sterilization processing system 20 according to the second embodiment. The sterilization treatment system 20 is different from the sterilization treatment system 10 in that three irradiators 6a-1, 6a-2, 6a-3 are integrated into one irradiator 6b. FIG. 3B is a cross-sectional view of the Y-Z plane through the lamp axis of the sterilization processing system 20.

  By integrating the three irradiators 6a-1, 6a-2, 6a-3 into one irradiator 6a, the cost for equipment investment can be reduced.

The features of the sterilization treatment system 20 differ from the features of the sterilization treatment system 10 in the following points.
(1) Irradiate with one irradiator equipped with a plurality of lamps. The lamp is a straight pipe type. The focal lengths of the light emission from each irradiator are different.

[Sterilization processing system according to the third embodiment]
With reference to FIG. 4, a sterilization processing system 30 according to the third embodiment will be described focusing on differences as compared to the sterilization processing system 20 according to the second embodiment.

  FIG. 4 illustrates the lamp 2 used in the sterilization treatment system 30. As shown in FIG. FIG. 4A shows a U-shaped lamp, and FIG. 4B shows a rectangular lamp. These lamps have a lamp tube, part of which extends in the Y direction (or has a Y direction component). Depending on the shape, the plurality of lamps 2 of the sterilization processing system 20 according to the second embodiment can be replaced with a relatively small number of lamps.

The features of the sterilization treatment system 30 differ from the features of the sterilization treatment system 10 in the following points.
(1) Irradiate with one irradiator equipped with one or two lamps. The lamp is not a straight tube type, but is a lamp tube partially extending in the Y direction (or having a Y direction component), for example, a U-shaped lamp or a rectangular lamp. Focal lengths of light emission from portions extending in each Y direction are different.
(4) Since irradiation is performed from one portion extending in each Y direction (or having a Y direction component) to one container, the irradiation per time is relatively few pulses (for example, 2 pulses) Irradiation of

[Evaluation test of the embodiment]
In order to confirm the effect of this embodiment, a food bacteria test was performed. In addition, it should be understood that in this experiment, a large amount of artificially untreated bacteria was adhered to the inner surface of the container and propagated to determine the difference in bactericidal effect. In the food container of the sterilization treatment process in an actual food manufacturing and processing maker, even in the prior art, the viable count after treatment is at a level that can be regarded as zero.

The device configuration of the sterilization treatment system 100, 10 used in the experiment is as follows.
Device size: 1200 x 200 mm
Mounting lamp: Arc length 850 mm Effective length 700 mm
In this experiment, the inactivation effect (sterilizing ability) was confirmed by applying dead grass (spores) to the inner surface and confirming the number of viable cells before and after pulse irradiation.

Table 1 shows the sterilization of dead bacteria (spores) of the conventional sterilization treatment system 100 (conventional example) shown in FIG. 1A and the sterilization treatment system 10 (examples 1 and 2) according to the first embodiment shown in FIG. 2A. It is experimental data of an effect.
In the pulse irradiation method of the conventional example, six continuous pulse irradiation of 600 J pulses is performed. In the first embodiment, a pulse of 600 J is continuously irradiated for two pulses at the position of (A) in FIG. There is. In the second embodiment, the output energy of the pulse is lowered to 400 J and the same irradiation is performed.

From the results of Example 1 of Table 1, it can be confirmed that the inactivation effect -LOG (N / N ₀ ) = 2 of the conventional example is improved to -LOG (N / N ₀ ) = 2.5. As a result, it has been confirmed that the irradiation unevenness caused by the shape of the irradiation object is reduced, the sterilization processing speed of the irradiation object is maintained, and a high sterilization effect can be obtained without increasing the lamp output.

From the results of Example 2, even if the output energy of the pulse is lowered from 600 J to 400 J, it can be confirmed that the same bactericidal effect as the inactivation effect of the conventional example-LOG (N / N ₀ ) = 2 can be obtained. The As a result, it was confirmed that the irradiation unevenness caused by the shape of the irradiation object is reduced, the sterilization processing speed of the irradiation object is maintained, and the sterilization effect equivalent to the conventional one can be obtained even if the lamp output is further reduced. Furthermore, it has been confirmed that the lamp life is extended and the running cost of the sterilizer is reduced.

[Others]
As mentioned above, although the embodiment of the flash light pulse sterilization processing system to the container concerning the present invention was described, these are illustration and it does not limit the present invention at all. The scope of the present invention is defined by the appended claims.

2: Lamp 4, 4-1, 4-2, 4-3: Reflector, 6 a, 6 a-1, 6 a-2, 6 a-3, 6 b: Irradiator 7: Cooling duct, 8: Container, Food container, 10: Sterilization treatment system, 12: Conveyor, conveyer, 16: luminescence, 20: Sterilization treatment system, 30: Sterilization treatment system, 100: Sterilization treatment system,

Claims (5)

In the flash pulse sterilization processing system for the container,
A conveyor for transporting a container to be sterilized in one direction (X direction);
A plurality of irradiators provided with a single lamp for pulse irradiation of ultraviolet light, respectively, above the conveyor (Z direction);
The lamp is disposed such that the direction (Y direction) of the lamp axis is orthogonal to the traveling direction (X direction) of the container,
The light emissions from the plurality of irradiators have different focal lengths.
When the container is conveyed immediately below the lamps provided in each irradiator, the conveyor is stopped, the lamps are irradiated with ultraviolet light pulses, and the ultraviolet light pulse irradiation is repeated sequentially for each irradiator. . In the flash pulse sterilization processing system for the container,
A conveyor for transporting a container to be sterilized in one direction (X direction);
And an irradiator having a plurality of lamps for pulse irradiation of ultraviolet light above the conveyor (in the Z direction);
The lamp is disposed such that the direction (Y direction) of the lamp axis is orthogonal to the traveling direction (X direction) of the container,
The light emissions from the plurality of lamps have different focal lengths.
When the container is conveyed immediately below each lamp provided in the irradiator, the conveyor is stopped, the lamp is irradiated with an ultraviolet pulse, and the flash pulse sterilization processing system sequentially repeats the ultraviolet pulse irradiation for each lamp . In the flash pulse sterilization processing system according to claim 2,
A flash pulse sterilization processing system in which the plurality of lamps are replaced with a relatively small number of U-shaped lamps or rectangular lamps. In the flash pulse sterilization treatment system according to any one of claims 1 to 3,
A flash pulse sterilization treatment system, wherein the distance between adjacent lamps or the distance of the portions of the adjacent lamps extending in each Y direction is determined in relation to the distance L between the adjacent containers in the X direction. In the flash pulse sterilization treatment system according to any one of claims 1 to 4,
The flash pulse sterilization processing system, wherein the lamp is a pulsed xenon lamp.

Images