JP6460569B2 - Sterilization treatment system for containers - Google Patents

Description

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

  In food manufacturing and processing manufacturers, it is important to reliably sterilize food containers. Due to the diversification of consumer needs, reliable sterilization of food containers is required by reducing the salinity of food, eliminating preservatives, extending the shelf life, and so on.

  Currently, in place of heat treatment and sterilization by chemicals, development of sterilization technology capable of sterilization without heating and non-contact is in progress. As such a non-heated and non-contact sterilization technique, flash pulse sterilization has attracted attention.

  A xenon flash lamp is used in the flash pulse sterilization processing system. The light emitted from the xenon flash lamp contains abundant ultraviolet rays having a wavelength of 200 to 300 nm which are effective for sterilization.

  The flash sterilization treatment system using a xenon flash lamp has a strong sterilization effect, is easy to control the light emission pulse, does not generate any residue because of non-contact, and is subject to treatment due to very short pulse irradiation. It has the effect that there is little influence on. On the other hand, the flash sterilization treatment system has a problem that only a portion that can be irradiated with light can be sterilized.

  The present inventors searched and investigated prior art documents regarding the invention for controlling the timing of pulse irradiation, focusing on the dependency of the light irradiation described in this application on the shape of the food container, but could not find it. .

  The flash sterilization treatment system has a strong sterilization effect as long as it can reliably irradiate the object to be treated. However, assuming an actual food manufacturing / processing maker site, it was found that light irradiation intensity (irradiance unevenness) was present on the sterilization surface of the food container due to the shape of the food container being processed. .

  Accordingly, an object of the present invention is to provide a sterilization treatment system that can reliably irradiate the sterilization surface of a container without depending on the shape of the container.

  In view of the said objective, the sterilization processing system which concerns on this invention is the conveyance conveyor which conveys in one direction, the container which is the object of the sterilization process arrange | positioned on the said conveyance conveyor, and the conveyance direction above the said conveyance conveyor. A sterilization treatment system comprising: a lamp for flashing ultraviolet rays arranged so as to cross at right angles; and a reflecting mirror arranged to cover the lamp on the opposite side of the lamp from the conveyor. When the container has moved to a position directly below the lamp, the conveyor is stopped, and the container is flashed by the lamp. Flashing is performed by the lamp at a previous time point, and flashing is performed by the lamp at a time point after a predetermined time from the stop cancellation time point.

  Furthermore, the sterilization processing system according to the present invention is configured to be orthogonal to the transport direction above the transport conveyor, a transport conveyor that transports in one direction, a container that is a sterilization target disposed on the transport conveyor, and the transport conveyor. A sterilization treatment system comprising: a lamp for flashing ultraviolet light disposed; and a reflecting mirror disposed on the opposite side of the lamp from the conveying conveyor so as to cover the lamp, a) First flash irradiation is performed on the container at the first position (time t = a−b) at which all of the reflected light can be received, and (b) the container is directly below the lamp. At (time t = a), the container is irradiated with a second flash, and (c) the last position where the reflected light can be received by the container (time t = a + b + c, provided that , C is the stop time) and the third flashlight It is carried out.

  Furthermore, the sterilization processing system according to the present invention is configured to be orthogonal to the transport direction above the transport conveyor, a transport conveyor that transports in one direction, a container that is a sterilization target disposed on the transport conveyor, and the transport conveyor. A sterilization treatment system comprising: a lamp for flashing ultraviolet light disposed; and a reflecting mirror disposed on the opposite side of the lamp from the conveying conveyor so as to cover the lamp, a) between the first position at which the container can receive all of the reflected light and a position directly below the lamp (period from time t = a−b to t = a); (B) At a position (time t = a) where the container is directly below the lamp, a second flash irradiation is performed on the container, and (c) the container is moved to the lamp. All reflected light from a position directly below (Period from time t = a for t = a + b + c. However, c is the stop time) until the last possible position receiving, the third flash light irradiation is performed on the container.

  Further, in the sterilization processing system, the first flash irradiation and the third flash irradiation may be performed while the transport conveyor is transported, and the second flash irradiation may be performed while the transport conveyor is stopped. .

  Further, in the sterilization processing system, the first flash light irradiation, the second flash light irradiation, and the third flash light irradiation may be performed while the transport conveyor is transporting.

  Furthermore, in the sterilization processing system, the lamp may be a xenon flash lamp.

  ADVANTAGE OF THE INVENTION According to this invention, the sterilization processing system which can light-irradiate the sterilization processing surface of a container reliably can be provided, without depending on the shape of a container.

FIG. 1 is a diagram illustrating an outline of a food container sterilization system. FIG. 2 is a diagram for explaining the timing of pulse irradiation in a conventional sterilization processing system. FIG. 3 is a diagram illustrating the timing of pulse irradiation in the sterilization processing system according to the present embodiment.

  Hereinafter, embodiments of a sterilization processing system for a container according to the present invention will be described in detail with reference to the accompanying drawings. In the figure, the same reference numerals are assigned to the same elements, and duplicate descriptions are omitted.

(Sterilization system)
FIG. 1 is a diagram illustrating an outline of a food container sterilization system. A container 8 as a sterilization target is placed on the conveyor 12 and is carried in the direction of the arrow. Inside the irradiator 6, a lamp 2 for sterilizing the container 8 is provided. The lamp 2 is provided with a reflecting mirror 4 in order to effectively use the light emitted from the lamp. In general, a plurality of containers 8 are arranged in the width direction of the transport conveyor 12 and are placed at intervals L in the traveling direction of the transport conveyor 12.

  The container 8 is typically a food container. In addition, it is a container for chemicals taken into the human body.

  The lamp 2 is typically a xenon flash lamp.

  When the container 8 placed on the transport conveyor 12 comes directly under the lamp 2, the transport conveyor 12 is temporarily stopped and sterilized by the ultraviolet light emitted from the lamp 2. Then, it restarts and moves in the direction of the arrow, and proceeds to the next food filling step. That is, the transport conveyor 12 stops each time the distance L is advanced, and performs sterilization.

  An example of such a sterilization system is a yogurt filling machine. The sterilization processing system of the yogurt filling machine is tact conveyance that repeats stop and conveyance, and has a stop of 0.75 seconds, a movement of 1.05 seconds, and a movement distance of 178 mm. Therefore, the conveyance speed is 170 mm / sec.

(Conventional sterilization process)
FIG. 2 is a diagram for explaining the timing of pulse irradiation in the conventional sterilization processing system 100. When the container 8 placed on the transport conveyor 12 is just below the lamp 2, the transport conveyor 12 is temporarily stopped, and the inside of the container is sterilized by emitting the ultraviolet light 2L from the lamp 2 a predetermined number of times. . Typically, the number of pulse emission is about 10 pulses.

  Here, for the convenience of explanation, the time when the container 8 is just below the lamp 2 is set as “time t = a”. As described with reference to FIG. 1, the transport conveyor 12 stops each time the arrangement distance L of the containers 8 is advanced, and performs sterilization.

  At this time, when the irradiation intensity distribution on the inner surface (irradiated surface) of the container 8 was measured, it was found that the irradiation intensity was strong or weak. That is, it has been found that there are portions (irradiance unevenness in illuminance distribution) where the irradiation intensity is relatively weak on the right side surface 8R, left side surface 8L and bottom surface 8B of the inner surface of the container as seen in the cross-sectional view of FIG.

  In the sterilization processing system 100, the reflected light f of the ultraviolet ray is adjusted so as to be focused in the container so that the illuminance is high at the lower end of the side surface where the irradiated light is difficult to hit. As a result, it has been found that the illuminance decreases on the side surface of the inner surface of the container 8 other than the lower end. Note that the level of illuminance can be determined by the density of light rays.

  Furthermore, regarding the right side surface 8R and the left side surface 8L, it is conceivable that the incident angle of ultraviolet rays is large. Regarding the bottom surface 8B, although the direct light from the lamp 2 is directly incident, it is conceivable that there are places where the reflected light from the reflecting mirror 4 cannot be used because the lamp 2 interferes.

  Even in the conventional sterilization treatment system 100, the number of viable bacteria is at a level that can be regarded as zero, and there is no problem in food hygiene. However, food hygiene management must be done with caution.

  The sterilization processing system according to the present embodiment solves the problem of the intensity of irradiation (irradiance unevenness) and enables more reliable sterilization processing.

(Sterilization treatment process according to this embodiment)
In the present embodiment, irradiation is performed with the position of the focal point f in the container close to the side surface side by irradiating immediately before the conveyance stop and immediately after the stop release. As a result, a portion with high illuminance is formed on the side surface other than the lower end portion, and unevenness in illuminance is eliminated.

  FIG. 3 is a diagram illustrating the timing of pulse irradiation in the sterilization processing system 10 according to the present embodiment. In FIG. 3, three types of states are depicted: a state immediately before the stop (left side), a stop state (center), and a state immediately after canceling the stop (right side). The stop state (center) is a state at time t = a when the conveyor 12 in the same state as in FIG. 2 stops. The state immediately before the stop (left side) is a state at time t = a−b during which the conveyor 12 is operating. The state immediately after the cancellation of the stop (right side) is a state of time t = a + b + c (where c is the time required for the stop) when the conveyor 12 is restarted.

  The situation of the lamp 2, the reflecting mirror 4 and the reflected light f is the same between the right side, center and left side states, and has not changed. While time elapses from time t = a−b to time t = a and further elapses until time t = a + b + c, the container 8 placed on the conveyor 12 (not shown) moves according to the elapsed time. However, the relative relationship of the container 8 with respect to the lamp 2, the reflecting mirror 4, and the reflected light f is changed. Time b is a very short time such that the container 8 moves slightly.

  At the time t = a when the conveyer 12 stops in the stop state (center), as described with reference to FIG. 2, the illuminance at the lower end of the side surface is strong as viewed in the cross-sectional view, and the illuminance at other side portions is Is relatively weak.

  However, at time t = a−b, which is the state immediately before the stop (left side), the focal point f is located in the middle of the right side surface 8R of the container 8 in the height direction. When ultraviolet irradiation is performed here, the right side surface 8R close to the focal point f has a high light density, and portions other than the lower end can be irradiated with strong reflected light.

  Further, the direct light (not shown) from the lamp 2 has a small incident angle with respect to the left side surface 8L of the inner surface of the container, and can be irradiated with relatively strong direct light. The influence of the lamp 2 is also reduced on the bottom surface 8B of the inner surface of the container, and the reflected light can be used effectively for irradiation.

  Similarly, at time t = a + b + c immediately after the stop is released (right side), the focal point f is located at the middle of the left side surface 8L of the container 8 in the height direction. When ultraviolet irradiation is performed here, the left side surface 8L near the focal point f has a high light density, and portions other than the lower end can be irradiated with strong reflected light.

  Further, the direct light (not shown) from the lamp 2 has a small incident angle with respect to the right side surface 8R of the inner surface of the container, and can be irradiated with relatively strong direct light. The influence of the lamp 2 is also reduced on the bottom surface 8B of the inner surface of the container, and the reflected light can be used effectively for irradiation.

  Here, the specification of the position of the container 8 immediately before the stop (t = a−b) and immediately after the stop release (t = a + b + c) will be considered.

  Before the stop (t = a−b), the container 8 can receive only a part of the reflected light because the right side surface 8R is obstructed, and cannot receive all of the light (Note: Ignore that lamp 2 is in the way.) Immediately before the stop (t = a−b), the container 8 can receive all of the reflected light for the first time. Accordingly, the position of the container 8 immediately before the stop (t = a−b) is specified as the first position where all the reflected light can be received.

  Similarly, immediately after the stop is released (t = a + b + c), the container 8 can receive only a part of the reflected light and cannot receive all of the reflected light because the left side surface 8L interferes. The container 8 can receive all of the reflected light until immediately after the stop is released (t = a + b + c). Accordingly, the position of the container 8 immediately after the stop is released (t = a + b + c) is specified as the last position where all the reflected light can be received.

  As described above, the position of the container 8 immediately before the stop, immediately after the stop, and immediately after the stop release can be specified by performing a trial in advance. The lamp 2 may (1) physically detect the position of the container 8 by a position sensor or the like and perform pulse irradiation, or (2) the transport conveyor moves at a predetermined speed, so stop (t = a). As a reference, the position of the container immediately before the stop (t = a−b) and immediately after the stop release (t = a + b + c) may be calculated by time, and pulse irradiation may be performed.

  In the prototype stage of this embodiment, two pulses of ultraviolet light are emitted at the time t = a−b immediately before the stop, six pulses of ultraviolet light are emitted at the stop time t = a, and two ultraviolet rays are emitted at the time t = a + b + c immediately after the stop is released. Pulsed.

(effect)
In order to confirm the effect of this embodiment, a food bacteria test was performed. Table 1 shows experimental data on the bactericidal effect on Bacillus subtilis (spore) of the conventional pulse irradiation shown in FIG. 2 and the pulse irradiation of this embodiment shown in FIG.

  It should be noted that this experiment was carried out by artificially attaching and breeding a large amount of untreated bacteria on the inner surface of the container in order to determine the difference in sterilizing effect. In the food container of the sterilization treatment process in an actual food manufacturing / processing manufacturer, the number of viable bacteria after the treatment is at a level that can be regarded as zero even in the conventional technology.

  According to Table 1, the number of viable bacteria of 1.0E + 04 (cfu / cuff) according to the prior art was reduced to about / 3 by 3.8E + 03 (cfu / cuff) in this embodiment. The inactivation effect was also improved from 2.1 to 2.6.

  As described above, in the conventional technology and the food container after sterilization treatment, the number of viable bacteria after the treatment is at a level that can be regarded as zero in the conventional technology, but by using the sterilization treatment system according to this embodiment, In addition, more reliable sterilization treatment has become possible.

(Modification)
(1) In this embodiment, at the time of stop (t = a), the conveyor 12 is stopped and pulse irradiation is performed, and the transfer is performed immediately before the stop (t = a−b) and immediately after the stop is released (t = a + b + c). It has been described that pulse irradiation is performed without stopping the conveyor 12. However, the conveyor 12 may be stopped and pulsed irradiation may be performed immediately before the stop (t = a−b) and immediately after the stop is released (t = a + b + c).

  (2) In this embodiment, the case of the tact conveyance which assumed the conveyance conveyor following a sterilization process and the next food filling process was demonstrated. However, both processes may be separated. In the case of the sterilization process alone, pulse irradiation is performed while transporting the transport conveyor 12 without stopping at any time point immediately before the stop (t = a−b), immediately after the stop (t = a), or immediately after the stop is released (t = a + b + c). You may go. Since the flash pulse emission time is as short as several hundred μsec to several msec, almost the same effect can be expected.

  (3) “Just before stop (t = a−b)” and “immediately after stop release (t = a + b + c)” described with reference to FIG. 3 are optimum irradiation states for side irradiation of the container, respectively. However, these need not be limited. From the time immediately before the stop (t = a−b), the container 8 can effectively use the totally reflected light. The container 8 can use the total reflected light effectively until the time immediately after the stop is released (t = a + b + c). Therefore, the irradiation immediately before the stop may be performed at an arbitrary time within the period from t = a−b to t = a. Similarly, irradiation immediately after the stop cancellation may be performed at an arbitrary point in time from t = a to t = a + b + c.

    Alternatively, the irradiation immediately before the stop may be performed continuously during the period from t = a−b to t = a while being transported by the transport conveyor 12. Similarly, irradiation immediately after cancellation of stop may be performed continuously within a period from t = a to t = a + b + c.

    Furthermore, irradiation may be continuously performed during a period from t = a−b to t = a + b + c while being transported by the transport conveyor 12. In this case, it is preferable to increase or decrease the irradiation so that the number of irradiation pulses becomes maximum at time t = a.

(Conclusion)
As mentioned above, although embodiment regarding the sterilization processing system with respect to the container which concerns on this invention was described, these are illustrations and do not limit the scope of the present invention at all. Additions, deletions, changes, improvements, and the like that can be easily made by those skilled in the art within the present embodiment are within the scope of the present invention. The technical scope of the present invention is defined by the description of the appended claims.

2: Lamp, 2L: Ultraviolet light emission, 4: Reflector, 6: Irradiator, 8: Container, 8B: Bottom surface, 8L: Left side surface, 8R: Right side surface, 10: Sterilization processing system, 12: Conveyor, 100: Sterilization treatment system L: Interval, arrangement interval, f: Focus,

Claims (2)

A transport conveyor for transporting in one direction;
A container to be sterilized and disposed on the conveyor,
Above the transport conveyor, a lamp for flashing ultraviolet light arranged so as to be orthogonal to the transport direction;
In a sterilization processing system comprising a reflecting mirror arranged to cover the lamp on the side opposite to the conveyor of the lamp,
The sterilization processing system is a conveyance system that repeatedly stops and conveys,
With the lamp
(A) having said container, said conveyor all the reflected light at the first position can be received is stopped, the first flash light irradiation is performed,
(B) the transfer conveyor the containers are in position directly below the lamp will stop against the container, the second flash light irradiation is performed,
(C) with respect to said container, said conveyor will stop all reflected light at the last position which can be received, the third flash light irradiation is performed, sterilization system. In the sterilization processing system according to claim 1,
The lamp is a xenon flash lamp, a sterilization processing system.

Images