JP2005170393A - Method and apparatus for sterilizing container - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for sterilizing a container, which can reduce the amount of use of a sterilizer. <P>SOLUTION: The method for sterilizing the container includes a process of spraying the sterilizer, which is heated to 45 to 90°C, at least on the inside of the container standing upright under a heated atmosphere. The apparatus for carrying out the method comprises a heat insulating sterilizing chamber (2), which has an entrance and an exit for the container and contains hot air, a hot air supply duct (27), which supplies the hot air to the heat insulating sterilizing chamber (2), a rotary ceiling plate (2b), which transfers the container (15) from the entrance to the exit of heat insulating sterilizing chamber (2), and a plurality of nozzles (30 and 33), which spray the heated sterilizer at least on the inside of the container (15) that is transferred while being kept stand upright. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method and apparatus for sterilizing containers such as PET bottles filled with various foods and beverages such as drinking water, juice, oolong tea, and milk coffee.

  As a sterilization method for containers such as PET bottles, use a sterilization method using a liquid sterilant such as hydrogen peroxide, peracetic acid, or a peracetic acid sterilant that is a mixed medicine of acetic acid, and then clean the container with aseptic cleaning water. The container-packed beverage manufacturing method in which a container after washing is filled with a beverage sterilized or sterilized in an aseptic space and the container is sealed with a sterilized cap is currently generally used as a method for manufacturing an aseptic filled beverage. .

As a container sterilization method used in this aseptic filling method, for example, as shown in FIG. 2 of Patent Document 1, the container is held in an inverted state, and a liquid sterilizer is sprayed onto the inner and outer surfaces of the container. A method of rinsing is commonly used. In the aseptic filling method, a sterilization method (Patent Document 2) that sterilizes the container by introducing mist generated by condensing the droplets of the other sterilizing agent into the container, or hot water of 63 ° C. or higher is used. Container sterilization methods such as a method of sterilizing a container and further sterilizing with a disinfectant (Patent Document 3) have been proposed.
JP 2002-332017 A JP 2001-39414 A JP 7-291236 A

  These methods have problems such as an increase in cost required for container sterilization due to the use of a large amount of a bactericidal agent, and in particular, sterilization of the bottom of the inner surface of the container tends to be uneven. Accordingly, there is a demand for the development of a new container sterilization method that can reduce the amount of the sterilizing agent while being able to perform sufficient sterilization.

  The present invention has been made in order to meet the above-mentioned demand, and is used for implementing a novel container sterilization method capable of significantly reducing the amount of sterilizing agent used while realizing sufficient container sterilization, and the implementation of this method. It is an object of the present invention to provide an apparatus for performing the above.

  The container sterilization method of the present invention that achieves the above object includes a step of spraying a sterilizing agent heated to 45 ° C. to 95 ° C. on at least the inner surface of an upright container in a heated atmosphere. .

  In one aspect of the present invention, in the container sterilization method, the sterilizing agent is sprayed on at least the inner surface of the container in an upright state, and a part of the sterilizing liquid droplet adhering to the inner surface of the container stays at the bottom of the container for a certain period of time. It is characterized by that.

  1 aspect of this invention WHEREIN: This container sterilization method is characterized by including the process of detecting the quantity of the bactericidal agent which retains in a container bottom part.

  Further, the container sterilization apparatus of the present invention that achieves the above-mentioned object has a container inlet and outlet, a heat insulation sterilization chamber that accommodates heated air, and a temperature holding means for maintaining the heat insulation sterilization chamber at a predetermined temperature. And container transfer means for transferring the container in an upright state from the inlet to the outlet of the thermal sterilization chamber, and at least the inner surface of the container transferred by the container transfer means in the thermal sterilization chamber at 45 ° C to And one or a plurality of nozzles for spraying a disinfectant heated to 95 ° C.

  In one aspect of the present invention, the container sterilization apparatus includes a mechanism in which a nozzle for spraying a sterilizing agent on at least an inner surface of the container is inserted into the container from the container mouth.

  In one aspect of the present invention, the container sterilizer includes a sterilizing agent distributing unit that distributes a sterilizing agent, a sterilizing agent supply path that supplies the sterilizing agent from the sterilizing agent distributing unit to the nozzle, and a sterilizing agent supply path. And a disinfectant heating means provided.

  In one aspect of the present invention, the container sterilization apparatus is characterized in that the temperature holding means is a heating means for supplying and / or circulating air heated in the heat sterilization chamber.

  In one aspect of the present invention, the container sterilization apparatus is characterized in that the temperature holding means is a heating means using an electric heater capable of heating the heat-insulating sterilization chamber.

  In one aspect of the present invention, the container sterilization apparatus is characterized in that the temperature holding means is a heating means for supplying / circulating a heated fluid to the inside of the wall in the heat sterilization chamber.

  In another aspect of the present invention, the container sterilizer includes a means for detecting the amount of the sterilizing agent staying at the bottom of the container at the outlet of the container.

  According to the container sterilization method of the present invention, when a normal temperature sterilizer is used by spraying at least the inner surface of a container in an upright state in a heated atmosphere with a sterilizer heated to 45 ° C. to 95 ° C. Compared with the above, the bactericidal effect is enhanced, and since the bactericidal agent is sprayed, the amount of the bactericidal agent used can be reduced as compared with the conventional method of rinsing the container by spraying the liquid bactericidal agent. Also, when the container is in an inverted state, the sprayed disinfectant is difficult to reach the bottom of the container, and even if it reaches the bottom of the container, the heated disinfectant will immediately vaporize, so that the container bottom cannot be sufficiently sterilized. In order to achieve sufficient sterilization, it is necessary to lengthen the spraying time, which increases the amount of sterilizing agent used. However, according to the present invention, the inner surface of an upright container is sterilized. Since the agent is sprayed, some of the sterilizing liquid droplets adhering to the inner surface of the container flow to the bottom of the container and stay at the bottom of the container while the container is held for a certain period of time in the sterilization process. Sufficient sterilization can be achieved.

  More importantly, according to the sterilization method of the present invention, since the spraying of the heated sterilizing agent is performed in a heated atmosphere, the sterilizing agent attached to the container as the heated sterilizing agent attached to the container evaporates. Even if the heat of vaporization is deprived and the temperature of the attached sterilizing agent is about to drop rapidly, the container is in a heated atmosphere, so that such a rapid temperature drop of the attached sterilizing agent can be prevented, A predetermined sterilizing effect by the agent can be obtained, and the amount of the sterilizing agent used can be minimized. Further, as the adhering germicide vaporizes, even if a partial non-uniformity of the adhering fungicide temperature due to the shape of the container is generated, the container is in a heated atmosphere, and thus such an adhering fungicide temperature is not stable. Uniformity can be minimized and therefore substantially uniform sterilization can be achieved throughout the container. Therefore, if the disinfectant temperature is partially uneven depending on the location of the container, it will be necessary to extend the spray time of the disinfectant in order to perform sufficient disinfection throughout the container, which increases the amount of disinfectant used. However, according to the present invention, substantially uniform sterilization can be performed over the entire container, and in this respect as well, the amount of the sterilizing agent used can be minimized.

  According to the container sterilization apparatus of the present invention, it can be used for carrying out the container sterilization method of the present invention, and the above object can be sufficiently achieved.

  In one aspect of the present invention, the container sterilizer includes a sterilizing agent distributing unit that distributes the sterilizing agent, a sterilizing agent supply path that supplies the sterilizing agent from the sterilizing agent distributing unit to the nozzle, and the sterilizing agent supplying unit. By further comprising a bactericide heating means provided in the path, the mechanism can be heated in the bactericide supply path through which the bactericide passes immediately before spraying. Further, a sterilizing agent tank for storing the sterilizing agent is provided on the upstream side of the sterilizing agent distributing unit, and the sterilizing agent is supplied to the sterilizing agent distributing unit as necessary. In addition, about heating of a disinfectant, it is possible to perform suitably between a disinfectant tank and a disinfectant supply path.

Embodiments of the present invention will be described below.
Containers to be subjected to the sterilization method of the present invention include plastic bottles such as PET bottles and polyolefin bottles, as well as various plastic containers and glass containers for filling food, metal cans, bottle-shaped cans, and the like.

  As the sterilizing agent used in the sterilizing method of the present invention, liquid sterilizing agents such as peracetic acid-based sterilizing agent, hydrogen peroxide, hypochlorous acid-based sterilizing agent can be cited as typical examples. If it is a liquid disinfectant which can be used for disinfection, there will be no limitation in particular.

  The disinfectant is used after being heated to 45 ° C to 95 ° C. The heating temperature is determined within this temperature range in consideration of the type and concentration of the sterilizing agent, the microbial species to be sterilized, the contents to be filled in the container, and the like.

  In the sterilization method of the present invention, the container is sterilized by spraying a heated liquid sterilizer on at least the inner surface of the container in an upright state, that is, with the mouth (opening) of the container positioned upward. Do. The reason for spraying the sterilizing agent in an upright state is that, as described above, a part of the sterilizing liquid droplets adhering to the inner surface of the container flows to the bottom of the container and the container is held for a certain time in the sterilization process. This is because, by staying at the bottom, sufficient sterilization can be achieved even if the injection time is short.

  In order to spray the warming disinfectant on the inner surface of the container, the spray nozzle may be inserted into the container, or may be performed without inserting the spray nozzle into the container. The advantage of inserting the spray nozzle into the container is that when the container is a bottle, the disinfectant spray pattern on the inner surface of the bottle is not hindered by the diameter of the bottle mouth. The advantage of not inserting the spray nozzle into the container is that the structure of the sterilizer is simple and the manufacturing cost is low.

  In order to completely sterilize the container, it is preferable to sterilize not only the inner surface of the container but also the outer surface at the same time.

  One of the important features of the sterilization method of the present invention is that the container is sterilized by spraying a sterilizing agent in a heated atmosphere. For example, the container has an inlet and an outlet, passes the container through a heat-sterilized chamber containing heated air, and sprays the heat-sterilizing agent from the spray nozzle onto the container while the container passes through the heat-sterilized chamber. Can be done. The temperature of the heating atmosphere is preferably substantially the same as or higher than the temperature of the warming disinfectant. Therefore, the temperature of the heating atmosphere is 45 ° C. to 95 ° C., preferably 64 ° C. to 70 ° C., similar to the heating temperature of the bactericide.

  By spraying the germicide in a heated atmosphere, in addition to the effect of preventing the adhesive germicide temperature from decreasing due to the heat of vaporization being removed, there is also an effect of reducing the decomposition rate of the germicide. Together, these effects can achieve a reduction in the amount of fungicide used.

  By detecting the amount of the sterilizing agent staying in the container in the vicinity of the outlet of the heat-insulating sterilization chamber, the spray state of the sterilizing agent can be monitored. By knowing whether or not a predetermined amount of the sterilizing agent is retained, it is possible to effectively perform process management such as guaranteeing sterilization of the container and clogging of the spray nozzle. As a means for detecting the amount of the sterilizing agent staying at the bottom of the container, the liquid level of the sterilizing agent is measured by photoelectric means or image processing with a camera, or the weight of the container is measured and the result is sterilized. Various means such as conversion to the amount of the agent can be used.

Hereinafter, an embodiment of an apparatus for carrying out a sterilization method according to the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a plan view schematically showing an embodiment of a container sterilization apparatus according to the present invention, FIG. 2 is a partial side view showing the main part of the sterilization apparatus, and FIG. It is a figure which fractures | ruptures and shows the outer side wall surface of an inlet_port | entrance and an exit.

  In FIG. 1, a container sterilization apparatus 1 includes a thermal sterilization chamber 2. The container is transferred in an upright state in the direction of the arrow along the container conveyance path 3, and is transferred in an upright state from the inlet 7 of the heat sterilization chamber 2 through the turrets 4, 5, 6. As shown in FIG. 3, the thermal sterilization chamber 2 is formed as an annular tunnel provided with an inlet 7 and an outlet 8 of the container. In order to prevent heated air from escaping outside the sterilization chamber, a plurality of temperature-controlled bactericidal shower curtains 9 are provided near the inlet 7. Thereby, the outflow of the heated air in the sterilization chamber is prevented, and the outer surface of the container is heated and sterilized. A plurality of bactericidal shower curtains 12 are also provided near the outlet 8. FIG. 3 shows an example in which three sets of disinfectant shower curtains are installed in the vicinity of the inlet 7 and the vicinity of the outlet 8, respectively, but the number of disinfectant shower curtains to be installed is appropriately determined according to the line manufacturing conditions and the like. Can do. As shown in FIG. 4, each sterilizer shower curtain is formed by spraying a sterilizer from a plurality of nozzles 13 provided on both sides in the width direction of the thermal sterilization chamber 2 toward the container 15. Each nozzle 13 is connected to a sterilizing agent supply pipe 17 branched from a sterilizing agent supply main pipe 16 to which a sterilizing agent is supplied from a sterilizing agent tank (not shown) that stores a sterilizing agent provided above the central portion of the sterilizing chamber 2. Has been.

  The annular heat sterilization chamber 2 is formed by a fixed portion 2a composed of an outer peripheral wall 19, an inner peripheral wall 20, an inclined bottom wall 21 and an annular rotating ceiling plate 2b. The rotary ceiling plate 2b is fixed to the tip ends of a plurality of ceiling plate support rods 23 which are arranged so as to project from the rotary shaft 22 in the center of the sterilization chamber, and are connected to the rotary shaft 23. When the rotary shaft 22 is driven to move by the electric motor 24, the rotary ceiling plate 2b is configured to rotate and move along the upper edge of the fixed portion 2a of the thermal sterilization chamber 2. In order to obtain a heat retaining effect, it is desirable that the outer peripheral wall 19, the inner peripheral wall 20, and the bottom wall 21 have a double structure. Moreover, although the form which rotates a top | upper surface part is described in this Embodiment, by changing arrangement | positioning of the spray nozzle 30, the container holding | grip part 25, etc., the top | surface part is fixed and the inner wall side is rotated. It is also possible to do.

  A container gripping portion 25 is fixed to the lower surface of the rotating ceiling plate 2b at a predetermined interval. When the container 15 is transferred to the inlet 7 of the heat-insulating sterilization chamber 2, the container 15 is gripped by the container gripping portion 25 and rotated. As the ceiling plate 2b rotates, the heat sterilization chamber 2 moves to the outlet 8. Therefore, the rotating ceiling board 2b constitutes a container transfer means in the apparatus of the present invention.

  In order to stabilize the temperature of the thermal sterilization chamber 2, heating air is supplied to the thermal sterilization chamber 2. An end of a heated air supply duct 27 connected to a heated air supply source 26 (FIG. 1) is opened in the vicinity of the inlet of the outer peripheral wall 19 of the fixed portion 2 a of the thermal sterilization chamber 2. The end of the heated air exhaust duct 28 is open near the outlet. Air heated to a temperature substantially equal to or higher than that of the sterilizing agent heated from the heated air supply source 26 is supplied into the heat-insulating sterilization chamber 2 through the heated air supply duct 27, and the heated air is exhausted from the heated air. It returns to the heated air supply source 26 through the duct 28. Therefore, the inside of the heat insulation sterilization chamber 2 is kept at a temperature substantially equal to or higher than the temperature of the heated sterilizer. As the heat retention mechanism of the heat sterilization chamber, a mechanism using a heat insulating material or the like on the wall surface of the heat sterilization chamber, a mechanism using a heating device such as an electric heater capable of controlling the atmospheric temperature in the heat sterilization chamber, Various mechanisms such as a mechanism for supplying and / or circulating a heated fluid or steam to a pipe or the like provided in the inside of the wall or in the thermal sterilization chamber, or a combination of these mechanisms can be used.

  The sterilizing agent distributor 18 is fixed to the upper end of the rotary shaft 22, and the sterilizing agent distributor 18 is connected to a sterilizing agent supply pipe 29 at a predetermined interval corresponding to the fixed position of the container grip 25. The disinfectant supply pipe 29 constitutes a disinfectant supply path in the present invention. Although a plurality of the bactericidal agent supply pipes 29 are provided, only one is shown in FIG. 3 for convenience of illustration. A spray nozzle 30 for sterilizing the inner surface of the container 15 toward the container opening is provided on the inner surface of the rotating ceiling plate 2 b above the opening of the container 15, and this nozzle 30 is connected to the sterilizing agent supply pipe 29. Has been. Moreover, the tube type heater 36 is provided in the edge part of the disinfectant supply piping 29 close | similar to the nozzle 30, and heats a disinfectant to predetermined temperature within the temperature range of 45 to 95 degreeC. Therefore, the spray nozzle 30 continues to spray the heated germicide on the inner surface of the container 15 by rotating together with the rotating ceiling board 2b. In the present invention, the tube heater 36 constitutes a sterilizing agent heating means provided in the sterilizing agent supply path.

  In addition, a plurality of fixed spray nozzles 33 are provided in the fixed portion 2a of the thermal sterilization chamber 2 at appropriate intervals so as to be positioned on both sides of the container 15 and below the bottom wall. And spray the disinfectant on the outer surface of the bottom wall. These spray nozzles 33 are connected to a sterilizing agent supply branch 32 branched from the sterilizing agent supply tube 31. The disinfectant supply pipe 31 is also provided with a tube heater (not shown), which heats the disinfectant to a predetermined temperature.

  Reference numeral 34 denotes a cleaning nozzle that injects cleaning water for cleaning the container gripping portion 25, and reference numeral 35 denotes a drain pipe for discharging the sterilizing agent that has finished sterilizing the container 15.

  Returning to FIG. 1, a container inverted / drainage part 37 composed of turrets 38, 39, 40, 41 is provided adjacent to the outlet 8 of the thermal sterilization chamber 2. The container in the upright state is inverted while being transferred by the rotation of the turret group of the container inversion / drainage unit 37, and the sterilizing agent remaining in the container is discharged. In addition, you may make it provide the mechanism in which a disinfectant is further retained for a predetermined period of time at the time of discharge | emission.

  The container which has been inverted and discharged with the bactericide is transferred from the turret 41 through the turret 42 to the rinser 43 through the inlet 43a of the rinser 43 having an annular container transfer path. As the rinser 43, a known apparatus for cleaning the container by spraying or spraying sterile water from a nozzle (not shown) onto at least the inner surface, preferably the inner and outer surfaces, of the inverted container can be used.

The container that has been cleaned by the rinser 43 is transferred to the next stage process such as filling the contents through the turrets 44 and 45.
Note that the thermal sterilization chamber 2, the container inversion / drainage unit 37, and the rinser 43 are all disposed in hermetically sealed machine covers 46, 47, 48, and an aseptic environment is maintained.

  In addition, in the said embodiment, in order to prevent the heated air in the heat insulation sterilization chamber 2 from escaping outside, the shower curtain by spraying of a disinfectant was used, but other heat insulation means such as heat insulation by warm air were used. Also good. Further, a container preheating mechanism for heating the container by a mechanism for replacing the air in the container with the heated air may be provided in front of the inlet 7 of the thermal sterilization chamber 2.

Experimental example

  Using a 500 ml PET bottle as a container and a peracetic acid disinfectant (Toyo-aktiv) with a peracetic acid concentration of 2000 ppm as a disinfectant, the PET bottle is in an upright state in a heated room at 60 to 64 ° C. in a heated atmosphere. The bactericidal effect of spraying a bactericide heated to 67 ° C. on the bottle inner surface was examined. Using a full cone nozzle as the spray nozzle, place the PET bottle so that the nozzle mouth of this nozzle is 20 mm above the mouth of the PET bottle, and the spray pattern of the bactericide sprayed from the nozzle is The disinfectant was sprayed on the inner surface. The flow rate of the disinfectant was 0.6 L / min at 0.2 MPa.

  Bacillus subtilis var.glogigii IFO (NBRC) 13721 was used as a test bacterium, and the number of bacteria that survived on the inner surface of the PET bottle as a result of sterilization by sterilization time of 4 seconds, 8 seconds, and 12 seconds was examined. The results are shown in Table 1. In addition, the number of surviving bacteria in each sterilization time has shown the result and average value which performed the test by n = 3 about each sterilization time. In all cases, the number of surviving bacteria was zero.

  As a result of the test, in the conventional bottle inverted rinse method, the amount of fungicide used was about 6 liters per minute, whereas according to the present invention, the amount of fungicide used to achieve the same bactericidal effect was about 0.6 L. It was found that it can be reduced to / min.

It is a top view which shows the outline of one Embodiment of the container sterilizer which concerns on this invention. It is a partial side view which shows the principal part of a sterilizer. It is a perspective view which shows the principal part of a sterilizer. It is a figure which shows the shower curtain by the disinfectant provided in the entrance and exit vicinity of the thermal insulation sterilization room.

Explanation of symbols

1 Container sterilizer 2 Thermal insulation sterilization chamber 2a Rotating ceiling board (container transfer means)
27 Heating air supply duct (heating air supply means)
30, 33 Spray nozzle 36 Tube heater (disinfectant heating means)

Claims (10)

A container sterilization method comprising spraying at least an inner surface of a container in an upright state in a heated atmosphere with a sterilizer heated to 45 ° C to 95 ° C. 2. The container sterilization according to claim 1, wherein a sterilizing agent is sprayed on at least an inner surface of the container in an upright state, and a part of the sterilizing liquid droplet adhering to the inner surface of the container stays at the bottom of the container for a certain period of time. Method. 3. The container sterilization method according to claim 2, further comprising a step of detecting the amount of the sterilizing agent staying at the bottom of the container. A thermal sterilization chamber having an inlet and an outlet of the container and containing heated air; temperature maintaining means for maintaining the thermal sterilization chamber at a predetermined temperature; and from the inlet of the thermal sterilization chamber toward the outlet One or a plurality of container transfer means for transferring the container in an upright state, and spraying a sterilizing agent heated to 45 ° C. to 95 ° C. on at least the inner surface of the container transferred by the container transfer means in the heat-insulating sterilization chamber A container sterilizing apparatus. The container sterilizing apparatus according to claim 4, wherein the nozzle for spraying the sterilizing agent on at least the inner surface of the container includes a mechanism for inserting the sterilizing agent into the container from the container mouth. A disinfectant distribution unit that distributes the disinfectant, a disinfectant supply path that supplies the disinfectant from the disinfectant distribution unit to the nozzle, and a disinfectant heating means provided in the disinfectant supply path. 6. The container sterilization apparatus according to claim 4 or 5, characterized in that: The container sterilization apparatus according to any one of claims 4 to 6, wherein the temperature holding means is a heating means for supplying and / or circulating air heated to the heat sterilization chamber. The container sterilization apparatus according to any one of claims 4 to 6, wherein the temperature holding means is a heating means using an electric heater capable of heating the heat sterilization chamber. The container sterilization apparatus according to any one of claims 4 to 6, wherein the temperature holding means is a heating means for supplying and / or circulating a heated fluid to the inside of the wall in the heat sterilization chamber. The container sterilizer according to any one of claims 4 to 9, further comprising means for detecting an amount of the sterilizing agent staying at the bottom of the container at the outlet of the container.

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