Sterile water production system

Abstract

Provided is a sterile water production system using sterile filters, wherein sterile water can be continuously produced.　Reverse osmosis (RO) water is supplied to a liquid feed line 22A of the sterile water production system 10 via a pump 12. The sterile water production system 10 comprises, in the stated order from the upstream side: a first sterile filter 16 for sterilizing the RO water; second sterile filters 18A, 18B provided in parallel so that it is possible to switch therebetween; and a UV sterilizer 20 for sterilizing water by irradiation with ultraviolet rays. A sampling line 40 is branched from the liquid feed line on the upstream side of the UV sterilizer 20, and the number of microbes in sampled water is detected at a microbe monitoring device 44. If the number of microbes detected by the microbe monitoring device 44 during sterile water production is at or above a predetermined value, the flow path to be traversed is switched between the second sterile filters 18A, 18B arranged in parallel.

Description

Sterile water production system

[0001] The present invention relates to a sterile water production system that sterilizes water using a sterile filter and ultraviolet sterilization.

[0002] Sterile water is used for many purposes in aseptic filling systems, which fill containers with contents in a sterile environment. For example, in the container washing process, chemicals such as hydrogen peroxide solution are sprayed to sterilize the containers and caps, and sterile water is used to rinse them away. Sterile water is also used for rinsing the sterile chamber and as a lubricant, among other uses. Traditionally, this sterile water has been produced using ultra-high temperature (UHT) sterilizers. However, these devices require a large amount of energy to heat water to ultra-high temperatures, resulting in significant carbon dioxide emissions. In recent years, reducing carbon dioxide emissions has been called for to reduce environmental impact, as highlighted in "13. Take concrete measures to combat climate change" in the SDGs. Furthermore, UHT sterilizers have the problem of high initial costs and high running costs due to their high energy consumption. To address these issues, a water sterilizer that combines a sterile filter and an ultraviolet sterilizer without performing UHT sterilization is known (see Patent Document 1).

[0003] Patent No. 7316558

[0004] However, in such water sterilizers that combine a sterile filter and an ultraviolet sterilizer, the microorganisms trapped in the sterile filter accumulate over time, making long-term continuous operation unsafe. Therefore, if the number of microorganisms detected by the testing device exceeds a predetermined value, sterile water cannot be supplied until the problem is resolved.

[0005] An object of the present invention is to enable the continuous production of sterile water in a sterile water production system using a sterile filter.

[0006] A first aspect of the present invention is a sterile water producing system comprising: a water supply means for supplying water; a water sterilization means for sterilizing the water supplied from the water supply means; and a control means for controlling the water sterilization means, wherein the water sterilization means comprises a first sterile filter; an ultraviolet sterilization means arranged downstream of the first sterile filter and for sterilizing the water by irradiating it with ultraviolet light; a plurality of second sterile filters arranged in parallel and switchable between the first sterile filter and the ultraviolet sterilization means; and a microorganism testing means arranged upstream or downstream of the ultraviolet sterilization means and for testing the number of microorganisms in sampled water, wherein the control means, when producing sterile water, passes the water through one of the second sterile filters arranged in parallel, and, if the number of microorganisms detected by the microorganism testing means is equal to or greater than a predetermined value, switches to a flow path that passes through a different second sterile filter arranged in parallel.

[0007] The second invention of the present invention, the sterile water production system, is characterized in that, in the first invention, when sterile water is produced, any of the second sterile filters arranged in parallel is used, and a sterilization process can be performed on the second sterile filter that is not being used.

[0008] According to the present invention, it is possible to continuously produce sterile water in a sterile water production system using a sterile filter.

[0009] The present invention relates to a system for producing sterile water, a method for producing sterile water, a method for manufacturing sterile water, a method for producing ...

[0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Fig. 1 is a block diagram showing the layout of a sterile water producing system according to one embodiment of the present invention.

[0011] The sterile water production system 10 of this embodiment produces sterile water using a sterile filter and an ultraviolet sterilization device. The sterile water production system 10 receives, for example, reverse osmosis (RO) water or PAA (peracetic acid) or alkaline cleaning solution from a COP (Cleaning Out of Place) facility via a pump 12 (water supply means). The RO water delivered by the pump 12 is converted into sterile water through a water sterilization means, which is arranged in this order from upstream: a prefilter 14, a first sterile filter 16 (water sterilization means), a second sterile filter 18 (water sterilization means), and a UV (ultraviolet) sterilization device 20 (water sterilization means, ultraviolet sterilization means). The sterilized water is then supplied to a rinser or chamber as, for example, rinse water. The rinse water is used in the rinser to wash away chemicals such as hydrogen peroxide solution sprayed on containers and caps for sterilization, and in the sterile chamber to rinse and lubricate the interior of the chamber.

[0012] The pre-filter 14, first sterile filter 16 and second sterile filter 18 are, for example, microfiltration filters (MF), with the filtration accuracy increasing the further downstream the filter is located, with filtration accuracies of, for example but not limited to, 0.5 μm, 0.2 μm and 0.1 μm. The pre-filter 14 and first sterile filter 16 are connected in series in this order to a single liquid supply line 22A, and drain valves 15 and 17 are provided on the pre-filter 14 and first sterile filter 16, respectively.

[0013] The downstream side of the liquid feed line 22A branches at branch point B1 into multiple parallel liquid feed lines, and each liquid feed line is provided with a second sterile filter 18. In this embodiment, it branches into two liquid feed lines 22B and 22C. From the upstream side, liquid feed lines 22B and 22C are each provided with three-way valves 24A and 24B and second sterile filters 18A and 18B. Two ports of the three-way valves 24A and 24B connect branch point B1 to each of the second sterile filters 18A and 18B, and the remaining port is each connected to the downstream end of a hot water sterilization line 26.

[0014] The second sterile filters 18A, 18B are provided with drain valves 28A, 28B, respectively, and drain valves 30A, 30B are provided downstream (near the outlets) of the second sterile filters 18A, 18B, respectively.

[0015] The downstream sides of liquid feed lines 22B and 22C are joined at confluence C1 via three-way valves 32A and 32B, respectively, and connected to a single liquid feed line 22D. Liquid feed line 22D is provided with UV sterilization device 20, and its downstream side branches at branch point B2 into, for example, two liquid feed lines 22E and 22F. Liquid feed line 22E is provided with an on-off valve 34A and connected to a rinser, and liquid feed line 22F is provided with an on-off valve 34B and connected to a sterilization chamber.

[0016] Two ports of the three-way valves 32A, 32B connect the second sterilizing filters 18A, 18B to the UV sterilizer 20, and the remaining port is connected to the upstream end of the hot water sterilization line 26. A CIP (Cleaning In Place) device 36 and a pump 38 are provided on the hot water sterilization line 26 from the upstream side. The CIP device 36 can be supplied with cleaning water for hot water sterilization.

[0017] A sampling line 40 is connected to the liquid supply line 22D between the junction C1 and the UV sterilizer 20, and a microorganism monitoring device 44 (microorganism testing means, water sterilization means) is provided via a gate valve 42. Water (sampled water) drawn into the sampling line 40 from the liquid supply line 22D is discharged through the microorganism monitoring device 44 and a drain valve 46. The microorganism monitoring device 44 detects the number of microorganisms contained in the sampled water in real time and counts the number (e.g., the number detected per unit time).

[0018] In this embodiment, drain valves 15, 17, 28A, 28B, 30A, 30B, 46, three-way valves 24A, 24B, 32A, 32B, and opening / closing valves 34A, 34B are each automatically operated by a control device (control means) not shown based on signals from the microbial monitoring device 44, etc., to control the flow path of water within the sterile water production system 10.

[0019] Next, the operation of the sterile water producing system 10 of this embodiment from the initial processing to normal operation will be described with reference to Figures 2 and 3. Figure 2 is a block diagram explaining the initial operation at the start of operation, and Figure 3 is a block diagram explaining the operation during normal operation.

[0020] 2, at the start of operation, the sterile water production system 10 sterilizes each line except for the hot water sterilization line 26. That is, the control device controls the three-way valves 24A, 24B to communicate between the branch point B1 and the second sterile filters 18A, 18B and close the port connected to the hot water sterilization line 26, and the three-way valves 32A, 32B to communicate between the second sterile filters 18A, 18B and the junction C1 and close the port connected to the hot water sterilization line 26. The control device also opens the drain valves 15, 17, 28A, 28B, 46, the gate valve 42, and the on-off valves 34A, 34B, and closes the drain valves 30A, 30B.

[0021] PAA and alkaline cleaning solution are supplied to liquid supply line 22A via pump 12. As a result, PAA and alkaline cleaning solution flow through the paths indicated by the thick lines, sterilizing liquid supply lines 22A to 22F and sampling line 40, as well as pre-filter 14, first sterile filter 16, second sterile filter 18, UV (ultraviolet) sterilization device 20 (ultraviolet sterilization means), and microbial monitoring device 44.

[0022] At this time, the microorganisms trapped in the filters 14, 16, 18A, and 18B are sterilized, and the filters 14, 16, 18A, and 18B are flushed to remove the microorganisms trapped by the filters and discharge them through the drain valves 15, 17, 28A, and 28B.

[0023] Once the cleaning work in the above initial operation is performed for a predetermined period of time, the initial operation is completed, RO water is supplied to the liquid supply line 22A of the sterile water production system 10 through the pump 12, and normal operation for producing sterile water begins (see Figure 3).

[0024] During normal operation of the sterile water production system 10, sterile water is produced using one of the parallel second sterile filters 18A, 18B. That is, one of the three-way valves 24A, 24B connects the branch point B1 to the second sterile filter 18 and closes the port connected to the hot water sterilization line 26. The other of the three-way valves 24A, 24B connects the hot water sterilization line 26 to the second sterile filter 18 and closes the port connected to the branch point B1. In parallel with this, one of the three-way valves 32A, 32B connects the second sterile filter 18 to the junction point C1 and closes the port connected to the hot water sterilization line 26. The other of the three-way valves 32A, 32B connects the hot water sterilization line 26 to the second sterile filter 18 and closes the port connected to the junction point C1.

[0025] 3 shows a state in which sterile water is produced using second sterile filter 18B (the flow path of RO water supplied to liquid supply line 22A is shown by a thick solid line), and second sterile filter 18A is connected to hot water sterilization line 26. In normal operation, drain valves 15, 17, 28A, 28B, 30A, and 30B are all closed, and gate valve 42 and drain valve 46 are open.

[0026] For a while after the start of normal operation, the produced sterile water is used to rinse the cleaner, and then it is used to rinse the containers and caps. Note that Fig. 3 shows an example in which sterile water is supplied only to the rinser (opening / closing valve 34A is open, and opening / closing valve 34B is closed).

[0027] During normal operation, the microorganism monitoring device 44 constantly detects passing microorganisms, and when the number of detected microorganisms per unit time exceeds a predetermined number, it determines that the sterilization capacity of the UV sterilization device 20 is exceeded, and the control device switches the second sterile filter 18 used to produce sterile water from one side to the other. That is, the connection states of the above-mentioned three-way valves 24A, 24B and three-way valves 32A, 32B are reversed. When switching from the state shown in Figure 3, the second sterile filter 18A is connected to the branch point B1 and the junction point C1, and the second sterile filter 18B is connected to the hot water sterilization line 26.

[0028] The hot water sterilization line 26 forms a looped flow path through the second sterile filter 18. When the CIP device 36 and pump 38 are operated in this state, hot water is circulated through the looped flow path, and the second sterile filter 18 located on the flow path is subjected to sterilization and flushing treatments with hot water. In Figure 3, the second sterile filter 18A is connected to the hot water sterilization line 26, and the looped flow path is shown by a thick dashed line. The hot water used for hot water sterilization can be discharged from drain valves 28A, 28B and drain valves 30A, 30B downstream of the second sterile filters 18A, 18B in the looped flow path.

[0029] The sterilization process using hot water and the flushing process are carried out when the filter used to produce sterile water is switched between the second sterile filters 18A and 18B based on a signal from the microorganism monitoring device 44, and are carried out in parallel with the sterile water production process by the switched second sterile filter 18. The temperature of the hot water is, for example, 90°C, and the process is carried out for, for example, 30 minutes.

[0030] The sterile water production process using the switched second sterile filter 18 is also monitored by the microorganism monitoring device 44, and the second sterile filter 18 is switched under the same conditions, and this switching is repeated until the production of sterile water is completed.

[0031] As described above, according to the sterile water production system of this embodiment, the production of sterile water can be continued using the switched second sterile filter even while the sterilization process or flushing process of the second sterile filter is being performed, and sterile water can be produced continuously. In other words, there is no need to install multiple sterile water production lines for continuous sterile water production, which reduces installation space and initial costs.

[0032] In this embodiment, two second sterile filters 18 are arranged in parallel, but three or more second sterile filters 18 can also be arranged in parallel. Furthermore, in this embodiment, unused second sterile filters 18 are sterilized with hot water during normal operation. However, this is not limited to this. Sterilization with steam or a sterilant may also be performed on the second sterile filter 18, or flushing with RO water or the like may be performed after sterilization with steam or a sterilant. In this embodiment, a sampling line 40 is provided between the confluence C1 and the UV sterilization device 20. However, the sampling line may also be provided downstream of the UV sterilization device 20, and the sterile water that has passed through the UV sterilization device 20 may be monitored by a microorganism monitoring device 44. In this embodiment, each line of the sterile water production system 10 is sterilized at the start of operation, but sterilization may also be performed after operation is terminated. In this embodiment, the sterile water produced by the sterile water production system 10 is used as a rinse for containers and caps, but it may also be used for drinking.

[0033] In this embodiment, a microfiltration filter (MF) is used as the sterilization filter, but an ultrafiltration filter (UF) can also be used. The cleaning agent sprayed into the sterilization chamber may be recovered from a drain provided in the sterilization chamber and reused.

[0034] 10 Sterile water production system 12 Pump (water supply means) 16 First sterile filter (water sterilization means) 18 Second sterile filter (water sterilization means) 20 UV sterilization device (water sterilization means, ultraviolet sterilization means) 44 Microorganism monitoring device (microorganism testing means, water sterilization means)

Claims

1. A sterile water production system comprising: water supply means for supplying water; water sterilization means for sterilizing water supplied from the water supply means; and control means for controlling the water sterilization means, wherein the water sterilization means comprises a first sterile filter; ultraviolet sterilization means arranged downstream of the first sterile filter for sterilizing water by irradiating it with ultraviolet light; second sterile filters arranged in parallel and switchable between the first sterile filter and the ultraviolet sterilization means; and microbiological testing means arranged upstream or downstream of the ultraviolet sterilization means for testing the number of microorganisms in sampled water, wherein the control means, when producing sterile water, passes the water through one of the second sterile filters arranged in parallel, and, if the number of microorganisms detected by the microbiological testing means is equal to or greater than a predetermined value, switches the flow path to pass through a different second sterile filter arranged in parallel.

2. A sterile water production system as described in claim 1, characterized in that when producing sterile water, any of the second sterile filters installed in parallel is used, and a sterilization process can be performed on the second sterile filter that is not in use.

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