Sterilizing apparatus

Abstract

To reduce the amt. of a sterilizing agent to be used and to miniaturize equipment.SOLUTION: The injection nozzle 4 is equipped with a housing 21 having an internal space S formed therein, a mesh plate 22 having a large number of micropores, a ring-shaped part 21d provided to the upper part of the mesh plate 22 and having a through-hole 24 and an ultrasonic vibrator 23 for ultrasonically vibrating the mesh plate 22. The supply means 6 supplies a liquid sterilizer to the internal space S, causes the sterilizer to fall into the through holes 24 in the 21d of the ring-shaped portion, supplies the sterilizer to the upper portion of the mesh plate 22, and causes the ultrasonic vibrator 23 to ultrasonically vibrate the mesh plate 22, thereby spraying the sterilizer in the form of mist onto the sterilization object from below the mesh plate 22. Further, a recovery means 7 (recovery piping 13) for recovering the excess sterilizing agent excessively stored in the upper part of the mesh plate 22 is provided to prevent insufficient atomization.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a sterilizer, and more particularly to a sterilizer equipped with a supply means for supplying a liquid sterilant and a spray nozzle for spraying the atomized sterilant toward an object to be sterilized. [Background technology]

[0002] Conventionally, a sterilization device for sterilizing objects such as PET bottles has been known that includes a supply means for supplying a liquid sterilant and a spray nozzle for spraying a mist of the sterilant toward the object (Patent Documents 1 and 2). In the sterilization device of Patent Document 1, a mist of sterilant is vaporized from a liquid sterilant, and the mist of sterilant is transported to a spray nozzle using heated air, and the spray nozzle sprays the mist of sterilant. In addition, in the sterilization device of Patent Document 2, a liquid sterilant is supplied in a vaporized state to a chamber, and when an injection nozzle that injects compressed air is moved to a position where the chamber is installed, the atomized sterilant is sucked into the injection nozzle and sprayed onto the object to be sterilized. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-36343 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-162220 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the sterilization devices in Patent Documents 1 and 2 require the vaporized sterilant to be transported through piping to the junction with heated air or to the chamber, and the vaporized sterilant condenses in the piping, resulting in the problem of a large amount of sterilant being used.In addition, the use of heated air results in a problem of the equipment becoming larger in size. In view of these problems, the present invention provides a sterilization device that can reduce the amount of sterilizing agent used and also allows the equipment to be made smaller. [Means for solving the problem]

[0005] That is, the sterilization apparatus according to the invention of claim 1 is a sterilization apparatus equipped with a supply means for supplying a liquid sterilant and a spray nozzle for spraying the mist of sterilant toward an object to be sterilized, The injection nozzle includes a housing having an internal space, a mesh plate having a large number of minute holes provided at the bottom of the housing, a ring-shaped portion provided at the top of the mesh plate and having through holes, and an ultrasonic vibrator that ultrasonically vibrates the mesh plate, the supply means supplies a liquid disinfectant into the internal space of the housing, drops the disinfectant into the through-holes of the ring-shaped portion, and supplies the disinfectant onto an upper portion of the mesh plate; With the sterilant stored in the upper part of the mesh plate, the ultrasonic vibrator ultrasonically vibrates the mesh plate, so that the sterilant is sprayed in the form of mist from below the mesh plate onto the object to be sterilized, Furthermore, the present invention is characterized by the provision of a recovery means for recovering excess disinfectant accumulated in excess above the mesh plate. [Effects of the Invention]

[0006] According to the above invention, when a liquid disinfectant is stored above the mesh plate in the internal space of the spray nozzle, the disinfectant can be atomized and sprayed by ultrasonically vibrating the mesh plate. This minimizes loss of the sterilizing agent supplied to the spray nozzle by the supply means, and also makes it possible to reduce the size of the sterilizing device because heated air is not used to supply the sterilizing agent. On the other hand, in the spray nozzle of the above configuration, if an excess amount of disinfectant accumulates above the mesh plate, the disinfectant will pass through the mesh plate as a liquid, resulting in insufficient atomization of the disinfectant. Therefore, the excess disinfectant can be collected by the collection means, allowing the disinfectant to be sprayed stably. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a diagram showing the configuration of a sterilization device according to this embodiment. [Figure 2] Cross section of the injection nozzle [Figure 3] Diagram explaining the operating state [Figure 4] Graph showing the relationship between the liquid volume in the measuring tank and time DETAILED DESCRIPTION OF THE INVENTION

[0008] 1 shows a sterilizer 1 that constitutes a part of a filling system for filling beverages into containers such as PET bottles, and the sterilizer 1 constitutes a chemical liquid treatment system. The sterilizer 1 and the filling system are controlled by a control means (not shown). The sterilization device 1 includes a liquid supply tank 2 as a liquid supply means for storing a disinfectant as a chemical liquid, a first measuring tank 3A and a second measuring tank 3B for storing the disinfectant, and a plurality of spray nozzles 4 for spraying the disinfectant in a mist form. The first and second metering tanks 3A and 3B are each provided with a metering means 5 for metering the disinfectant, and between the first and second metering tanks 3A and 3B and each spray nozzle 4, there are provided a supply means 6 for supplying disinfectant to the spray nozzle 4 and a recovery means 7 for recovering any disinfectant that has surplus from the spray nozzle 4.

[0009] The liquid supply tank 2 contains a hydrogen peroxide solution of a predetermined concentration as a disinfectant, and a branched liquid supply pipe 11 is provided between the first and second metering tanks 3A and 3B, and first and second on-off valves V1 and V2 controlled by control means are provided at the branched portions. The first and second on-off valves V1 and V2 are controlled by a control means, and when the first on-off valve V1 is opened, the disinfectant is sent from the supply tank 2 to the first metering tank 3A by its own weight, and when the second on-off valve V2 is opened, the disinfectant is sent from the supply tank 2 to the second metering tank 3B. During this time, the control means closes the second on-off valve V2, and the liquid supply from the liquid supply tank 2 to the second measuring tank 3B is stopped.

[0010] The first and second measuring tanks 3A and 3B are containers of the same volume with open tops, and liquid supply pipes 11 from the liquid supply tank 2 are provided above the first and second measuring tanks 3A and 3B, respectively, so that the disinfectant is supplied from above. The measuring means 5 provided in the first and second measuring tanks 3A and 3B each includes a liquid level detection sensor 5a for detecting the liquid level of the chemical solution or a load cell 5b for measuring the weight of the measuring tank. The liquid level detection sensor 5a measures the amount of disinfectant contained in the first and second measuring tanks 3A and 3B based on the liquid level of the disinfectant contained in the first and second measuring tanks 3A and 3B, respectively, and the load cell 5b measures the amount of disinfectant contained in the first and second measuring tanks 3A and 3B based on the weight of the disinfectant contained in the first and second measuring tanks 3A and 3B. It should be noted that, with regard to the measuring means 5, either the load cell 5b or the liquid level detection sensor 5a may be omitted, and other means may be used as long as they are capable of measuring the amount of disinfectant. The measuring means 5 continuously measures the disinfectant in the first and second measuring tanks 3A and 3B, and when the disinfectant decreases as it is used in the spray nozzle 4, the control means calculates the amount of disinfectant to be used based on this decrease in the amount of disinfectant. The control means calculates the concentration of the disinfectant sprayed from the spray nozzle 4 based on the amount of disinfectant used, and if, for example, the amount of disinfectant used is insufficient, it determines that the concentration of the sprayed disinfectant does not reach the specified level.

[0011] The supply means 6 includes a supply pipe 12 arranged between the first and second metering tanks 3A, 3B and each injection nozzle 4, and a first three-way valve MV1 as a switching means provided on the supply pipe 12. The supply pipe 12 has both ends branched off, one end connected to the bottom of the first and second measuring tanks 3A and 3B, and the other end branched off and connected to each of the injection nozzles 4. The first three-way valve MV1 is provided at a junction of the first and second metering tanks 3A and 3B in the supply pipe 12, and is controlled by a control means. For example, when the first measuring tank 3A and the spray nozzle 4 are connected to each other, the disinfectant contained in the first measuring tank 3A is discharged into the supply pipe 12 by its own weight, and then distributed and supplied to each spray nozzle 4. This stops the liquid from being sent from the second measuring tank 3B to the spray nozzle 4.

[0012] The recovery means 7 includes a recovery pipe 13, one end of which is arranged between the first and second metering tanks 3A, 3B and each injection nozzle 4, a recovery pump 14 provided on the recovery pipe 13, and a second three-way valve MV2 as a switching means provided on the supply pipe 12. The recovery pipe 13 is provided with both ends branching off, one end being provided above the first and second measuring tanks 3A and 3B, and the other end being connected to each of the injection nozzles 4. As will be described later, the recovery pump 14 sucks excess disinfectant from the spray nozzle 4 and delivers it to the first and second measuring tanks 3A and 3B. The second three-way valve MV2 is provided at the branch point of the supply pipe 12 to the first and second metering tanks 3A and 3B, and is controlled by a control means to distribute the disinfectant delivered by the recovery pump 14 to the first metering tank 3A or the second metering tank 3B. For example, while the disinfectant is being supplied from the first metering tank 3A to the spray nozzle 4 by the first three-way valve MV1 of the supply means 6, the recovery means 7 recovers the disinfectant from the spray nozzle 4 to the first metering tank 3A by the second three-way valve MV2. As a result, a circulation path is formed between the first metering tank 3A and the injection nozzle 4 by the supply pipe 12 and recovery pipe 13, and by simultaneously switching the first and second three-way valves MV1 and MV2, a circulation path is also formed between the second metering tank 3B and the injection nozzle 4 by the supply pipe 12 and recovery pipe 13.

[0013] In this embodiment, the filling system includes a conveying means (not shown) for conveying the containers, and the injection nozzle 4 is provided above the conveying path of the containers conveyed by the conveying means. FIG. 2 shows a cross-sectional view of the injection nozzle 4, and the injection nozzle 4 is provided at a position spaced about several mm above the mouth of the container conveyed by the conveying means. The spray nozzle 4 includes a housing 21 having an internal space S formed therein, a mesh plate 22 having a large number of minute holes provided at the bottom of the housing 21, and an ultrasonic vibrator 23 that ultrasonically vibrates the liquid disinfectant. Further, in the internal space S of the injection nozzle 4, a supply pipe 12 constituting the supply means 6 and a recovery pipe 13 constituting the recovery means 7 are provided so as to protrude.

[0014] The housing 21 is composed of a cylindrical side portion 21a, a lid portion 21b attached to the upper part of the side portion 21a, a bottom portion 21c attached to the lower part of the side portion 21a, and a ring-shaped portion 21d provided on the inside of the side portion 21a, and by connecting these in an airtight state, the internal space S is formed inside. The supply pipe 12 and recovery pipe 13 are connected to the lid portion 21b so as to penetrate from top to bottom, and a through hole 24 drilled in the bottom portion 21c and ring-shaped portion 21d is located directly below the tip of the recovery pipe 13.

[0015] The mesh plate 22 is a metal member formed to have a larger diameter than the through-holes 24, and is provided with a large number of minute holes with a diameter of about 2.5 to 5 μm. Resin sealing members are provided on the upper and lower surfaces of the mesh plate 22 so as to surround the through holes 24, and the mesh plate 22 is sandwiched between the bottom portion 21c and the ring-shaped portion 21d via the sealing members. The ultrasonic vibrator 23 is a ring-shaped element fixed along the outer periphery of the mesh plate 22, and is ultrasonically vibrated by power from the cable C, causing the mesh plate 22 to which it is fixed to vibrate ultrasonically.

[0016] As described above, the through-hole 24 of the ring-shaped portion 21d is located at the top of the mesh plate 22, and the upper part of the through-hole 24 is formed with a tapered shape 24a so that the diameter increases upward. The supply pipe 12 is provided at the upper outside of the through hole 24 of the ring-shaped portion 21d, and the disinfectant that falls from the tip of the supply pipe 12 falls outside the through hole 24 of the ring-shaped portion 21d, and then falls into the through hole 24 due to the tapered shape 24a, and further falls onto the top of the mesh plate 22. Here, since the micropores in the mesh plate 22 have a small diameter, the liquid disinfectant cannot pass through the micropores due to surface tension, and is instead pooled above the mesh plate 22 . In this state, when the mesh plate 22 is ultrasonically vibrated by the ultrasonic vibrator 23, the disinfectant on the upper part of the mesh plate 22 is also ultrasonically vibrated, and the liquid disinfectant passes through the micro-holes and turns into a mist, which is sprayed downward.

[0017] On the other hand, if an excessive amount of disinfectant accumulates on the top of the mesh plate 22, the effect of surface tension disappears and the disinfectant passes through the micropores as a liquid, which may result in insufficient atomization of the disinfectant and a reduced disinfection effect. Therefore, the end of the recovery pipe 13 is provided above the through hole 24, and when excess disinfectant accumulates above the mesh plate 22, the excess disinfectant is sucked out by the recovery pump 24. Specifically, a gap of approximately 3 to 5 mm is provided between the tip of the recovery pipe 13 and the mesh plate 22, and any sterilant stored above the mesh plate 22 in excess of this gap is sucked in by the recovery pump 14. The amount of disinfectant that can be stored above the mesh plate 22 can be adjusted by the diameter of the through holes 24 and the distance between the mesh plate 22 and the recovery pipe 13, and the distance between the tip of the recovery pipe 13 and the mesh plate 22 is set according to this amount. The disinfectant sucked through the recovery pipe 13 is recovered into the first metering tank 3A or the second metering tank 3B which form the circulation path by the second three-way valve MV2 as described above.

[0018] In this way, by atomizing and spraying the disinfectant from the spray nozzle 4, the disinfectant is discharged from the first and second metering tanks 3A and 3B. Therefore, the control means calculates the amount of disinfectant to be used based on the reduced amount of disinfectant measured by the metering means 5, and ensures the concentration of the mist of disinfectant sprayed from the spray nozzle 4. At this time, the circulated disinfectant flows into the first metering tank 3A or the second metering tank 3B from the recovery pipe 13, and as described above, by simultaneously switching the first and second three-way valves MV1 and MV2, a circulation path is formed between the first metering tank 3A and the spray nozzle 4, or between the second metering tank 3B and the spray nozzle 4. As a result, for example, while the disinfectant in the first measuring tank 3A is being sprayed by the spray nozzle 4, no disinfectant from the outside flows into the circulation path formed by the first measuring tank 3A and the spray nozzle 4, so the amount of disinfectant used can be accurately calculated and the concentration of the disinfectant sprayed can be guaranteed.

[0019] The operation of the sterilization apparatus 1 having the above configuration will be described below. Figure 3 is a diagram illustrating the switching operation between the first metering tank 3A and the second metering tank 3B, and Figure 4(a) is a graph showing the relationship between the amount of sterilant stored in the metering tanks and time during the switching operation, with the solid line indicating the amount stored in the first metering tank 3A and the dashed line indicating the amount stored in the second metering tank 3B. From t0 to t1 in Figure 4(a), the liquid supply tank 2 supplies disinfectant to the empty first and second metering tanks 3A and 3B, and a predetermined amount of disinfectant is stored in the first and second metering tanks 3A and 3B as shown in Figure 1. From this state, the filling system is activated, and when the sterilization device 1 starts operating (t1), the control means causes the spray nozzle 4 to spray the sterilant supplied from the first measuring tank 3A, as shown in Figure 3(a). Specifically, the first three-way valve MV1 of the supply means 6 and the second three-way valve MV2 of the recovery means 7 are connected to the first metering tank 3A. At this time, the supply of disinfectant from the supply liquid tank 2 to the first and second metering tanks 3A and 3B is stopped. Then, the disinfectant is supplied from the first measuring tank 3A to each spray nozzle 4 via the supply pipe 12, and at each spray nozzle 4, as shown in Figure 2, the disinfectant discharged from the tip of the supply pipe 12 falls into the inside of the housing 21 and then falls onto the top of the mesh plate 22 through the through hole 24 in the ring-shaped portion 21d. The ultrasonic vibrator 23 then ultrasonically vibrates the mesh plate 22, causing the liquid disinfectant on the top of the mesh plate 22 to turn into mist as it passes through the micro-holes, and is sprayed toward the container being transported below the spray nozzle 4, thereby sterilizing the inside of the container.

[0020] On the other hand, if more sterilant than necessary accumulates above the mesh plate 22 in the spray nozzle 4, the atomization of the sterilant will be insufficient, and the excess sterilant will be recovered by the recovery means 7. The recovery pipe 13 of the recovery means 7 is located above the through hole 24, and excess disinfectant above the mesh plate 22 is sucked by the recovery pump 14 and recovered into the first metering tank 3A via the second three-way valve MV2. A circulation path is formed between the first measuring tank 3A and the spray nozzle 4 by a supply pipe 12 and a recovery pipe 13, so that a portion of the disinfectant is recovered from the spray nozzle 4 to the first measuring tank 3A, making it possible to reuse the excess disinfectant. However, since the disinfectant supplied from the first metering tank 3A is sprayed by the spray nozzle 4, although a certain amount of disinfectant is circulated to the first metering tank 3A via the recovery pipe 13, the amount of disinfectant in the first metering tank 3A gradually decreases.

[0021] The measuring means 5 measures the disinfectant in the first measuring tank 3A, and the control means calculates the amount of disinfectant to be used from the amount of disinfectant that is decreasing, and also calculates the concentration of the atomized disinfectant sprayed from the spray nozzle 4 from the amount used. For example, if the amount of disinfectant used falls below a specified value, the control means determines that the concentration of the disinfectant sprayed is low, and issues a required warning and performs control such as stopping the filling system. The control means also monitors the metering means 5, and when the amount of disinfectant in the first metering tank 3A decreases to a predetermined amount (t2), switches the first three-way valve MV1 and the second three-way valve MV2. As a result, as shown in Figure 3(b), the supply pipe 12 and the recovery pipe 13 now connect the second metering tank 3B to the spray nozzles 4, and the disinfectant is supplied from the second metering tank 3B to each spray nozzle 4. In this case, as in the case where the first measuring tank 3A is used, the disinfectant supplied from the second measuring tank 3B is sprayed in atomized form from the spray nozzle 4, and any excess disinfectant at the spray nozzle 4 is collected in the second measuring tank 3B.

[0022] On the other hand, when the first three-way valve MV1 and the second three-way valve MV2 are switched at t2, the communication between the first metering tank 3A and the spray nozzle 4 is cut off, and at the same time the control means opens the first on-off valve V1 of the liquid supply piping 11 to supply the disinfectant from the liquid supply tank 2 to the first metering tank 3A. This causes new disinfectant to be replenished in the first metering tank 3A, and when the measuring means 5 recognizes that a predetermined amount of disinfectant has been contained in the first metering tank 3A, the control means closes the first on-off valve V1 to stop the supply of disinfectant (t3). During this operation, new disinfectant flows into the first metering tank 3A, but at this time the disinfectant in the second metering tank 3B is being supplied to the spray nozzle 4, and since there is no need to calculate the amount of disinfectant used in the first metering tank 3A, the concentration of disinfectant sprayed from the spray nozzle 4 is not affected.

[0023] Thereafter, when the metering means 5 determines that the amount of disinfectant in the second metering tank 3B has decreased to a predetermined amount (t4), the control means again switches the first three-way valve MV1 and the second three-way valve MV2, this time connecting the first metering tank 3A and the spray nozzle 4 via the supply pipe 12 and the recovery pipe 13. As a result, as shown in Figure 3(a), the disinfectant from the first metering tank 3A is sprayed again from the spray nozzle 4, and by opening the second on-off valve V2 of the liquid supply pipe 11, the disinfectant from the liquid supply tank 2 is supplied to the second metering tank 3B. Thereafter, by repeating the above-described operation, it becomes possible to continuously spray the disinfectant from the spray nozzle 4.

[0024] As described above, according to the sterilization apparatus 1 of the above embodiment, as shown in FIG. 3(a), even if sterilant is supplied from the first measuring tank 3A to the spray nozzle 4 while excess sterilant at the spray nozzle 4 is collected into the first measuring tank 3A, the amount of sterilant used can be accurately calculated, and the concentration of the sprayed sterilant can be guaranteed. Furthermore, as shown in FIG. 3(b), by refilling the first metering tank 3A with new disinfectant while the disinfectant in the second metering tank 3B is being supplied to the spray nozzle 4, disinfectant can be continuously supplied to the spray nozzle 4 without compromising the calculation results of the amount of disinfectant used in the second metering tank 3B.

[0025] 4(b) shows a graph for a configuration with only one measuring tank. In this configuration, when the amount of sterilant supplied from the measuring tank to the spray nozzle 4 decreases, sterilant is supplied from the liquid supply tank 2. The supply tank 2 supplies the metering tank with a larger amount of disinfectant than the amount of disinfectant consumed by the spray nozzle 4, thereby increasing the amount of disinfectant in the metering tank (t2 to t3'). However, during this period, the metering tank also supplies and recovers disinfectant between the spray nozzle 4, so if new disinfectant is also flowed in from the supply tank 2, the exact amount of disinfectant used cannot be calculated, and the disinfectant concentration cannot be guaranteed.

[0026] In the above embodiment, multiple injection nozzles 4 of the same configuration are provided, but it is also possible to form multiple internal spaces S inside one housing 21, and connect a mesh plate 22, an ultrasonic vibrator 23, a supply pipe 12, and a recovery pipe 13 to each internal space S. In the above embodiment, the first and second metering tanks 3A and 3B are alternately switched to supply the disinfectant to the spray nozzle 4, but it is also possible to use more metering tanks, for example, by providing a third metering tank. [Explanation of symbols]

[0027] 1 Sterilizer 2 Liquid supply tank 3A First measuring tank 3B Second measuring tank 4. Injection nozzle 5. Metering means 6. Supply means 7. Recovery means 11 Liquid supply pipe 12 Supply pipe 13 Recovery piping 14 Recovery pump MV1, MV2 1st and 2nd three-way valves (switching means)

Claims

1. A sterilization device equipped with a supply means for supplying a liquid sterilant and a spray nozzle for spraying the mist of sterilant toward an object to be sterilized, The injection nozzle includes a housing having an internal space, a mesh plate having a large number of minute holes provided at the bottom of the housing, a ring-shaped portion provided at the top of the mesh plate and having through holes, and an ultrasonic vibrator that ultrasonically vibrates the mesh plate, the supply means supplies a liquid disinfectant into the internal space of the housing, drops the disinfectant into the through-holes of the ring-shaped portion, and supplies the disinfectant onto an upper portion of the mesh plate; With the sterilant stored in the upper part of the mesh plate, the ultrasonic vibrator ultrasonically vibrates the mesh plate, so that the sterilant is sprayed in the form of mist from below the mesh plate onto the object to be sterilized, The sterilizer further comprises a recovery means for recovering excess sterilant accumulated in excess above the mesh plate.

2. the recovery means includes a recovery pipe that is provided to protrude into the internal space of the housing and has an end located above the through hole of the ring-shaped portion, 2. The sterilizer according to claim 1, wherein a gap is provided between the end of the recovery pipe and the mesh plate so that the sterilant stored above the mesh plate in excess of this gap can be sucked.

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