Sterilization method for pharmaceutical water production system and method for producing pharmaceutical water

Abstract

To provide a sterilization method of a medical water production system and a production method of medical water which heat raw water with good heat efficiency at the time of sterilization of inside a medical water production system, suppress a heat load of a water treatment device, and can efficiently obtain heating water at a desired temperature.SOLUTION: A sterilization method of a medical water production system 1 has: a raw water tank 2 for storing raw water; a water treatment device 4 for removing impurities contained in the raw water supplied from the raw water tank 2; a heat exchanger 3 which is arranged at the front stage of the water treatment device 4 and can heat the raw water; and a first circulation pipe L3 which is branched from a supply pipe L1 to the water treatment device 4 from the heat exchanger 3 and circulates a part of the heating water heated by the heat exchanger 3 to the raw water tank 2.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for sterilizing a pharmaceutical water production system and a method for producing pharmaceutical water, which are provided with heating means capable of efficiently heating raw water to obtain heating water for sterilization in order to sterilize the pharmaceutical water production system.

Background Art

[0002] Pharmaceutical water (for example, purified water, sterilized purified water, water for injection) used in the production of pharmaceuticals and the like is produced, for example, by using tap water or the like as raw water and passing this through a water treatment device such as a reverse osmosis membrane device or an electro-deionization device to remove impurities in the raw water by a purification process. Pharmaceutical water is required to have a predetermined water quality according to the pharmacopoeias of each country, and daily or regular water quality management is also required.

[0003] And in the production of such pharmaceutical water, the inside of the production device is sterilized regularly before and after the production. Usually, as this sterilization treatment, for example, heating water at 60°C or higher is passed through the inside of the production device for a predetermined time. And after performing the sterilization treatment in this way, the production of pharmaceutical water is carried out. The temperature of the raw water in the production of pharmaceutical water is usually about normal temperature (25°C).

[0004] As a device for producing pharmaceutical water capable of sterilization treatment, for example, a reverse osmosis membrane device and an electrically regenerated pure water production device are provided in this order. After the raw water is once treated by these devices and stored as treated raw water, the treated raw water is circulated in the system while being heated to enable sterilization treatment (for example, see Patent Document 1), a device having a reverse osmosis membrane device and an electric deionization device, and in the sterilization step, the concentrated water of the reverse osmosis membrane device, the concentrated water of the electric deionization device, demineralized water, etc. can be circulated to the raw water tank to enable sterilization treatment (for example, see Patent Documents 2 to 3), an ultraviolet sterilization device, a reverse osmosis membrane device, and an electric deionization device, capable of producing pharmaceutical water without using an activated carbon tower or a photocatalyst, and at the time of sterilization, a device capable of circulating the concentrated water of the heated reverse osmosis membrane device (for example, see Patent Document 4), a device having a polymer membrane filtration device for filtering the water to be treated obtained by a combination of reverse osmosis membrane treatment and ion exchange treatment (for example, see Patent Document 5), etc. are known.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Summary of the Invention

Problems to be Solved by the Invention

[0006] In order to sterilize the entire pharmaceutical purified water production system, it is necessary to raise the temperature until the water passing through the inside of the entire system reaches a temperature equal to or higher than the desired temperature required for sterilization treatment, and then maintain the temperature equal to or higher than the desired temperature for a predetermined time required for sterilization treatment. When using raw water as sterilized water, compared with the water passed through the water treatment device, the water stored in the raw water tank that sends the raw water to the water treatment device has a large heat capacity because there is a large amount of it, and it is difficult to increase the temperature.

[0007] Furthermore, as in Patent Documents 1 to 5 above, in the process of sterilizing the inside of the manufacturing device, when heating the raw water and passing it through the water treatment device, and circulating the permeated water and concentrated water obtained during the water passage to the raw water tank, since they are passed through the water treatment device, the temperature of the raw water that has been heated with great effort decreases, and it takes time to heat the heated water circulated during sterilization to a predetermined temperature. Also, in this case, since the piping path through which the heated water circulates to the raw water tank becomes relatively long, there is also a possibility that the temperature will decrease in this regard.

[0008] Therefore, the time required to reach the desired temperature is significantly shorter for the water passed through the water treatment device than for the water stored in the raw water tank. For this difference in time, the water treatment device will be further heated from the desired temperature. Also, heated water above the desired temperature will be passed through for a time exceeding a predetermined time. That is, an extra heat load will be imposed on the water treatment device. Also, for the amount of the extra heat load, extra energy is being consumed. There is also a problem that since the time required for heating itself becomes longer, the time required to resume the production of purified water after the sterilization treatment is also longer.

[0009] Therefore, since the thermal efficiency by heating does not improve by a certain level or more, sufficient energy saving cannot be achieved.

[0010] On the other hand, in the sterilization of such a pharmaceutical water production device, it is also necessary to be careful so that the heat load on the water treatment device does not increase due to the heated water used for the sterilization (so that the rapidly heated water does not flow into the water treatment device). Therefore, the heating rate of the raw water during the sterilization treatment is preferably, for example, 1 to 10 °C / min.

[0011] In this regard, when circulating at the subsequent stage of the water treatment apparatus as in Patent Documents 1 to 5 described above, considering the temperature drop as described above, it is necessary to set the set value in the heat exchanger higher than the temperature in the raw water tank targeted and heat it additionally. Therefore, the heat load on the water treatment apparatus increases, and there is a possibility of a decline in function. In addition, there is also a sterilization method in which a heater is provided in the tank and water is passed through the water treatment apparatus while heating. However, in this case, there is a problem that the part of the heater in the tank may cause problems such as the growth of bacteria.

[0012] Therefore, an object of the present invention is to provide a pharmaceutical water production system and a sterilization method thereof that can efficiently obtain heated water at a desired temperature while heating raw water with good thermal efficiency, suppressing the heat load on the water treatment apparatus, and sterilizing the inside of the pharmaceutical water production system.

Means for Solving the Problems

[0013] The pharmaceutical water production system of the present invention includes a raw water tank for storing raw water, a reverse osmosis membrane device, an electrodeionization device, an activated carbon adsorption device, an ultrafiltration membrane device, an ultraviolet sterilization device, and a mixed bed ion exchange device that can remove impurities contained in the raw water supplied from the raw water tank. A water treatment apparatus having at least one selected therefrom, a heat exchanger disposed in front of the water treatment apparatus and capable of heating the raw water supplied from the raw water tank, and a part of the heated water heated by the heat exchanger being branched from a supply pipe connected from the heat exchanger to the water treatment apparatus and circulated to the raw water tank. It is characterized by having a first circulation pipe.

[0014] The sterilization method of the pharmaceutical water production system of the present invention is as follows: a raw water tank for storing raw water, and at least one selected from a reverse osmosis membrane device, an electrodeionization device, an activated carbon adsorption device, an ultrafiltration membrane device, an ultraviolet sterilization device, and a mixed bed ion exchange device that can remove impurities contained in the raw water sent from the raw water tank. A water treatment device, a heat exchanger disposed in the front stage of the water treatment device and capable of heating the raw water supplied from the raw water tank, and a part of the heated water heated by the heat exchanger is branched from a supply pipe connected from the heat exchanger to the water treatment device and circulated to the raw water tank. In a pharmaceutical water production system having a first circulation pipe, the raw water sent from the raw water tank is heated by a heat exchanger to obtain heated water, the heated water is supplied to the water treatment device, and a part of the heated water is branched to the first circulation pipe and circulated to the raw water tank.

Effects of the Invention

[0015] According to the pharmaceutical water production system and its sterilization method of the present invention, the thermal efficiency when heating the raw water to heated water during the sterilization treatment is good, the time of the sterilization treatment can be shortened, and the sterilization treatment can be performed without causing a decrease in the function of the water treatment device or the like.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Mode for Carrying Out the Invention

[0017] Hereinafter, a pharmaceutical water production system according to an embodiment of the present invention and a sterilization method for the system will be described in detail with reference to FIGS. 1 to 2.

[0018] [Pharmaceutical Water Production System] As shown in FIG. 1, the pharmaceutical water production system 1 of the present embodiment includes a raw water tank 2, a heat exchanger 3, a water treatment device 4, and a pump 5.

[0019] The raw water tank 2 is a tank for storing raw water for producing pharmaceutical water. The raw water stored here can be used for producing pharmaceutical water or for obtaining heated water for sterilization. The raw water used here is the same as the raw water conventionally used for producing pharmaceutical water. For example, it includes municipal water, well water, industrial water, etc., and pretreated water obtained by pretreating these waters with an activated carbon adsorption device, a coagulation separation device, a deaeration device, a multi-layer filter, a microfiltration membrane (MF), a reverse osmosis membrane, an ion exchange device, etc.

[0020] The heat exchanger 3 is a device for adjusting the temperature of raw water, etc., and is mainly used during sterilization. When producing pharmaceutical water, the temperature of the raw water is usually set to about 25°C. If temperature adjustment is not necessary, heat exchange by the heat exchanger 3 may not be performed. The heat exchanger 3 is used to heat the raw water or treated water to a desired temperature during sterilization. As this heat exchanger 3, a known heat exchanger can be used without particular limitation.

[0021] The water treatment device 4 is a device for removing impurities contained in raw water and purifying it to obtain treated water of a predetermined water quality when manufacturing pharmaceutical water. Examples of such a water treatment device 4 include known devices such as a reverse osmosis membrane device (RO), an electro-deionization device (EDI), an activated carbon adsorption device (AC), an ultrafiltration membrane device (UF), an ultraviolet sterilization device (UV), and a mixed bed ion exchange device (MB).

[0022] The water treatment device 4 may have one or more of the above-described devices, and it is preferable to use two or more of them in combination. As an example of combining two or more treatment devices, a treatment device in which a reverse osmosis membrane device (RO) and an electro-deionization device (EDI) are arranged in the subsequent stage is more preferable.

[0023] The reverse osmosis membrane device (RO) can be used without particularly limiting the reverse osmosis membrane device known in the art, and it is a device for removing organic impurities and salts contained in raw water. The reverse osmosis membrane device can reduce the total organic carbon content (TOC), and for example, it is preferable to reduce the TOC to 500 ppb or less.

[0024] The electro-deionization device (EDI) is a device that can remove ions and the like in raw water and reduce the electrical conductivity by desalination treatment. Although an ion exchange resin device such as a normal desalination tower can also be used, the electro-deionization device is preferably used because continuously high-quality treated water can be obtained.

[0025] This electro-deionization device has, for example, anion exchange membranes and cation exchange membranes alternately arranged between an anode and a cathode, and alternately has desalination chambers partitioned by the anion exchange membranes and the cation exchange membranes and concentration chambers into which concentrated water containing the removed ion components flows. And the electro-deionization device has a mixture of anion exchange resin and cation exchange resin filled in the desalination chamber and electrodes for applying a DC voltage.

[0026] The pump 5 is a pump for supplying raw water from the raw water tank 2 to the heat exchanger 3, and the raw water supplied here circulates within the pharmaceutical water production system.

[0027] Here, in the pharmaceutical water production system 1 of the present embodiment, the heat exchanger 3 and the water treatment device 4 are connected in this order by the supply pipe L1, and further, a first circulation pipe L3 that branches from the supply pipe L1 and is connected to the raw water tank 2 is provided. This first circulation pipe L3 is a pipe used during sterilization.

[0028] The pharmaceutical water production system 1 of the present embodiment has a supply pipe L2 for obtaining treated water as pharmaceutical water from the water treatment device 4 and sending this to a storage tank or a use point.

[0029] Furthermore, the pharmaceutical water production system 1 is provided with a second circulation pipe L4 that branches from the supply pipe L2 and is connected to the raw water tank 2.

[0030] Also, the pharmaceutical water production system 1 of the present embodiment is provided with valves V0, V1a, V1b, V2a, and V2b for regulating and adjusting the flow of raw water and treated water. The operations of these will be described together with the description of the sterilization method below. Note that the valve V1a is not essential in the present embodiment.

[0031] [Sterilization Method for Pharmaceutical Water Production System] Next, the sterilization method for the pharmaceutical water production system described above will be explained. This sterilization method for the pharmaceutical water production system is a method of performing sterilization treatment within the system when the pharmaceutical water production system is started up or after continuous use for a certain period.

[0032] The sterilization method for this pharmaceutical water production system will be described in detail with reference to FIGS. 1 and 2. Before explaining the sterilization method, the production method of pharmaceutical water will be briefly explained.

[0033] 〈Production Method of Pharmaceutical Water〉 In the production of pharmaceutical water, in the pharmaceutical water production system 1 of the present embodiment, the raw water stored in the raw water tank 2 is supplied from the raw water tank 2 to the water treatment device 4. At this time, the raw water passes through the heat exchanger 3. However, since pharmaceutical water is usually produced at a temperature of about normal temperature (25 °C), it is heat-exchanged as necessary and adjusted to a desired temperature during its production. That is, when the raw water temperature is normal temperature, heat exchange in the heat exchanger 3 may not be necessary.

[0034] When the raw water is supplied to the water treatment device 4 through the supply pipe L1, the impurities contained in the raw water are removed by the water treatment device 4, and purified treated water (pharmaceutical water) is obtained.

[0035] At this time, the second circulation pipe L4 can be used to circulate the treated water to mix with the raw water stored in the raw water tank 2 and perform a circulation operation to perform the same treatment as above again. For example, for the purpose of continuously operating the pharmaceutical water production system 1 even when there is no demand for treated water at a use point described later, or for the purpose of obtaining more purified treated water, it may be used. Note that the first circulation pipe L3 is not used during the production of pharmaceutical water.

[0036] The pharmaceutical water obtained by such a method for producing pharmaceutical water is sent to a storage tank connected to the supply pipe L2, or, for example, sent as purified water to a use point. Alternatively, after treatment with an ultrafiltration membrane (UF) or a distiller, for example, maintained at 80 °C or higher, it may be supplied as WFI (water for injection) to a use point while circulating in a circulation system including a tank and a use point. After continuously performing such a pharmaceutical water production operation and continuing production for a predetermined time, the sterilization method described below is performed to keep the inside of the pharmaceutical water production system clean.

[0037] The time for continuing the production of pharmaceutical water can be arbitrarily set. Generally, sterilization is performed once a day to once every six months. However, in order to effectively prevent the contamination of bacteria and the like, it is more preferable to perform the sterilization treatment once a day to once every two months, and it is even more preferable to perform it once a week. If the interval between sterilization treatments is too long, it becomes difficult to effectively prevent the contamination of bacteria and the like. On the other hand, if the interval between sterilization treatments is too short, sufficient time cannot be taken for the production of pharmaceutical water, and the production efficiency deteriorates.

[0038] 〈Sterilization method〉 Next, the sterilization method of the pharmaceutical water production system will be described with reference to FIG. 2. The pharmaceutical water production system 1 shown in FIG. 2 is the same as the pharmaceutical water production system 1 in FIG. 1.

[0039] A sufficient amount of raw water is stored in the raw water tank 2, the valve V0 is closed, and the supply of raw water is stopped. This is to suppress the decrease in the temperature of the obtained heated water. Next, the raw water supplied from the raw water tank 2 is heated by the heat exchanger 3 and heated up to become heated water for thermal sterilization. This heated water is obtained by gradually heating it to a desired temperature while circulating inside the pharmaceutical water production system.

[0040] In this heating-up process, the heated water heated by the heat exchanger 3 is separated into heated water that is directly supplied from the supply pipe L1 to the water treatment device 4 and heated water that flows through the first circulation pipe L3 branched from the supply pipe L1 and is circulated to the raw water tank 2.

[0041] This is because if heated water at a suddenly high temperature is supplied to the subsequent water treatment device 4 to be heated, the heat load may increase and problems such as a decrease in the function of the device may occur. Therefore, a part of the heated water is directly supplied from the supply pipe L1 to the water treatment device 4, while the other heated water is circulated to the raw water tank 2 by the first circulation pipe L3 in order to perform the heating from the raw water to the heated water for thermal sterilization in a short time and with good heat energy.

[0042] At this time, it is preferable that the heating rate of the heated water is 1 to 10 °C / min. This heating temperature can be confirmed, for example, by providing a temperature measuring device at the outlet of the heat exchanger 3, the raw water tank 2, etc., and measuring the temperature change over time.

[0043] By separating the heated water in this way, the temperature of the heated water flowing into the water treatment device 4 can be gradually increased, and by circulating it to the raw water tank 2, the temperature drop of the heated water due to its flow into the conventional water treatment device 4 can be prevented, and it can be efficiently heated to the desired temperature.

[0044] Also, although the heated water is branched as described above, when the flow rate of the heated water supplied to the water treatment device 4 is Q1 and the flow rate of the heated water circulated to the raw water tank 2 is Q2, it is preferable that the ratio of these flow rates is such that the flow rate Q1: flow rate Q2 is 90:10 to 20:80, and more preferably 50:50 to 25:75. By setting such a flow rate ratio, while supplying the heated water to the water treatment device 4, the temperature rise of the heated water can be efficiently performed by the first circulation pipe L3. When the ratio of the flow rate Q2 is too small, it becomes difficult to efficiently heat the raw water tank 2. When the ratio of the flow rate Q2 is too large, there is a risk that the heating rate of the water stored in the raw water tank 2 becomes too large. In such a case, the heating rate of the water sent from the raw water tank 2 to the water treatment device 4 will also become too large.

[0045] The flow rates Q1 and Q2 of the branched heated water can be adjusted by setting the desired opening degrees of the valve V1a provided in the supply pipe L1 and the valve V1b provided in the first circulation pipe L3, respectively. The above-mentioned heating rate can also be adjusted to the desired range by adjusting the flow rates Q1 and Q2.

[0046] Also, the heated water supplied from the supply pipe L1 to the water treatment device 4 passes through the inside of the water treatment device 4 and is sent out from the supply pipe L2. Further, this heated water is circulated to the raw water tank 2 by the second circulation pipe L4.

[0047] By adopting such a circulation system, the water temperatures of the raw water tank 2 and the water treatment device 4 can be made substantially the same, and the time until the heating process ends after the heat exchanger outlet temperature reaches the specified temperature (when all lines reach the specified temperature) can be shortened. Immediately after the heating process ends, the temperature equalization process can be started, and sterilization can be performed in a short time. It is preferable that the difference between the time from the start of the heating process until the water supplied to the water treatment device 4 reaches the desired temperature and the time until the water flowing through the outlet of the raw water tank 2 reaches the desired temperature is within 10 minutes. Also, it is preferable that the temperature difference between the water supplied to the water treatment device 4 and the water flowing through the outlet of the raw water tank 2 is within 10°C.

[0048] In this way, the above operations are continuously performed until the heated water reaches the desired temperature. After reaching the desired temperature, sterilization treatment (temperature equalization process) of the pharmaceutical water production system with the heated water is performed for a predetermined time. Here, the temperature of the heated water for sterilization is 60°C or higher, preferably 60 - 90°C. Also, as the predetermined time for the sterilization treatment, a time sufficient for sterilization treatment may be set according to the configuration of the production system. For example, when the temperature is 60°C, the heated water may be passed through for 30 - 120 minutes, and when the temperature is 80°C, for 20 - 60 minutes.

[0049] Note that after reaching the predetermined temperature, in order to perform the sterilization treatment while maintaining this temperature, it is preferable to circulate the heated water through the second circulation pipe L4.

[0050] Also, at this time, the opening degrees of valves V1a and V1b can be changed to reduce the flow rate Q2 and increase the flow rate Q1. When changing the opening degrees in this way, it is also possible to provide control means that can change the opening degrees at a predetermined timing for switching from heating to sterilization (temperature equalization) or from sterilization (temperature equalization) to cooling.

[0051] When the sterilization treatment is completed sufficiently, then the cooling treatment of the heated water is carried out. This is again a process for manufacturing pharmaceutical water. In this cooling process, it may be carried out by a conventionally known method such as stopping the heating by the heat exchanger 3, supplying cold water to the heat exchanger 3, or controlling the heating amount by the heat exchanger 3. Also, the valve V0 may be opened to resume the supply of raw water to the raw water tank 2. At this time, just pay attention to the point that the cooling rate is carried out within a predetermined range so as not to cause a rapid temperature change, similar to the temperature rising rate described in the raw water heating process. This cooling rate is preferably the same as the above-mentioned temperature rising rate, 1 to 10 °C / min.

[0052] In this cooling operation, as long as the cooling rate is within the above range, the opening degrees of the valves V1a, V1b, V2a, and V2b may be set in any way. For example, while discharging the heated water from the supply pipe L2 to the outside of the system, a part of it is circulated to the raw water tank 2 through the second circulation pipe L4, and the cooling rate can be adjusted.

[0053] (Modification Example 1) Also, this ultrapure water production system 1 can be modified as shown in FIG. 3. That is, the ultrapure water production system 1 shown in this FIG. 3 is a production system having the same configuration as the ultrapure water production system 1 described in FIG. 1, but an example in which the arrangement relationship between the supply pipe L1 and the first circulation pipe L3 is made specific is described.

[0054] In the pharmaceutical water production system 1 shown in this FIG. 3, the supply pipe L1 is characterized in that it is arranged so as to pass near the raw water tank 2. That is, instead of arranging the supply pipe L1 so that the raw water or the heated water discharged from the heat exchanger 3 is immediately supplied to the water treatment device 4, the pipe arrangement position is changed so as to pass near the raw water tank 2 intentionally.

[0055] At this time, a first circulation pipe L3 that branches in the middle is provided in the supply pipe L1. In this modification, the length of the first circulation pipe L3 can be shortened and is provided so as to be as short as possible. In FIG. 3, among the supply pipe L1, the part from the heat exchanger 3 to the branch part is shown as the supply pipe L1a, and the part from the branch part to the water treatment device 4 is shown as the supply pipe L1b.

[0056] In this way, by shortening the length of the first circulation pipe L3, it is possible to reduce the degree of contamination due to the growth of bacteria, etc. in the first circulation pipe L3 that is not used during the production of pharmaceutical water. At this time, since raw water or heated water flows through the supply pipe L1 both during the production of pharmaceutical water and during sterilization, there is no need for special attention regarding contamination.

[0057] Also, it is preferable to arrange the part between the valve V1b and the raw water tank 2 (most of the first circulation pipe L3) so that its axis extends in the vertical direction. When provided in the vertical direction in this way, during the production of pharmaceutical water when water does not flow through this pipe, the stagnant water in this part flows out to the raw water tank 2, so there is no stagnant water. Therefore, problems such as the growth of bacteria in the stagnant water hardly occur.

[0058] The length of the first circulation pipe L3 is preferably shorter than 1 / 2 of the length of the supply pipe L1a, and more preferably shorter than 1 / 4. This length includes components such as the branch part, the connecting pipe to the raw water tank 2, and the valve V1b that must be provided at a minimum. The shorter the length including these components, the more preferable it is. Specifically, 2 m or less is preferable, and 1 m or less is more preferable. Also, although it is common to provide a T-shaped pipe at the part where the first circulation pipe L3 branches from the supply pipe L1 for branching, in some cases, the valve V1b is directly attached between this T-shaped pipe and the raw water tank 2. In this case, the length of the first circulation pipe L3 is substantially the total length of a part of the T-shaped pipe at the branch part, the valve V1b, and the connecting part protruding from the raw water tank 2. In this configuration, the length of the first circulation pipe L3 is the shortest and is the most preferable configuration.

[0059] Incidentally, although it was described that the first circulation pipe L3 portion preferably has its axis extending in the vertical direction, it suffices that the water inside the pipe can flow out to the raw water tank 2, and it is not necessary for the axis to coincide with the vertical direction. As long as the above-described operation is achieved, the axis of the pipe may be inclined at an angle with respect to the vertical direction. That is, it suffices that the valve V1b is higher than the connection portion of the raw water tank 2.

[0060] (Modification 2) In addition, in the connection portion between the first circulation pipe L3 and the raw water tank 2 of this ultrapure water production system 1, it is preferable that the portion for supplying the circulated heated water into the raw water tank 2 is a spray nozzle. As the spray nozzle, a known spray nozzle can be used, and a type that can be supplied into the tank while diffusing is preferable. Specifically, Spray Ball (KT series) manufactured by Tose Co., Ltd. etc. can be used as this spray nozzle.

[0061] By using the spray nozzle in this way, the heated water circulated by the first circulation pipe L3 can be supplied into the raw water tank 2 while diffusing, for example, in a shower shape. By doing so, the temperature rising efficiency during the production of heated water can be improved.

[0062] The reason why the temperature rising efficiency is improved is that the temperature distribution in the raw water tank is suppressed, so that the temperature rising rate can be stabilized.

[0063] In addition, the above-described Modification 1 and Modification 2 may be a pharmaceutical water production system having both configurations.

[0064] Incidentally, in the description of the above sterilization method, the heat treatment of the raw water is described in the mode of performing it from the beginning. However, before the heating, once the raw water stored in the raw water tank 2 is treated by the water treatment device 4 at room temperature, the entire amount of the treated water is circulated by the second circulation pipe L4, and after replacing the inside of the raw water tank 2 with the treated water by the water treatment device 4, the above sterilization method may be performed. Further, when the water treatment device 4 is composed of two or more devices, a part of it may be passed through the water treatment and circulated to the raw water tank 2.

[0065] For example, when a reverse osmosis membrane device (RO) and an electrodeionization device (EDI) are used as the water treatment device 4, the supply pressure during the passage of the heated water needs to be lower than that during the production of pharmaceutical water. Therefore, the water quality obtained by passing water through the reverse osmosis membrane device may exceed the water passage standard for the electrodeionization device, and it is not preferable to directly use it for the sterilization treatment of the electrodeionization device. This is effective in such a case.

[0066] In addition, the above circulation may be performed for the purpose of reducing the amount of water stored in the raw water tank 2. That is, for example, when a reverse osmosis membrane device (RO) and an electrodeionization device (EDI) are used as the water treatment device 4, during the above circulation, the concentrated water of the reverse osmosis membrane device (RO), the concentrated water of the electrodeionization device (EDI), and the electrode water are discharged out of the system, so that the water quality in the raw water tank 2 can be improved and the amount of water can be reduced at the same time. This is effective when the amount of water stored in the raw water tank 2 is too large and thus the heat capacity is too large when the valve V0 is closed to stop the supply of raw water in order to start the sterilization treatment. That is, by reducing the heat capacity of the raw water tank 2 before the temperature rise, the temperature rise in the raw water tank 2 during the temperature rise process can be increased to a desired speed, and the thermal efficiency can also be improved.

[0067] In the case of replacing with the treated water by the water treatment device 4 in this way, when the water treatment device 4 can obtain concentrated water in addition to the permeated water, such as a reverse osmosis membrane device or an electrodeionization device, in the implementation of the above sterilization method, the concentrated water may be circulated to the raw water tank 2.

Example

[0068] Hereinafter, the present invention will be described with reference to examples and comparative examples.

[0069] (Example 1) A pharmaceutical water production system 11 was prepared, which has a raw water tank 2, a heat exchanger 3, a reverse osmosis membrane device (RO) 41 as a water treatment device, and an electro-deionization device (EDI) 42 in this order, and has a supply pipe L1 and a first circulation pipe L3 branched therefrom, a supply pipe L2 and a second circulation pipe L4 branched therefrom.

[0070] Although not shown in the figure, in the supply pipe L2 of this pharmaceutical water production system 11, an ultraviolet irradiation device (UV) is provided between the electro-deionization device 42 and the branch portion of the second circulation pipe L4.

[0071] Specifically, the following were used for the above various devices. Heat exchanger: Single tube sheet multi-tube heat exchanger (STR65-0.5MR, manufactured by Toyo System Co., Ltd.) Reverse osmosis membrane device: 9 low-pressure PA type 8-inch modules (SU-720TS, manufactured by Toray Industries, Inc.), water recovery rate 55%, supply water flow rate 7.4 m 3 / h Electro-deionization device: 2 E-Cell (MK-3 PHARMHT, manufactured by SUEZ), water recovery rate 90%, supply water flow rate 3.7 m 3 / h Ultraviolet irradiation device: Sterilization type (NPX series, manufactured by Nippon Photo Science Co., Ltd.), irradiation dose 190W

[0072] Regarding this pharmaceutical water production system 11, first, municipal water was supplied to and stored in the raw water tank 2 as raw water. The supply of raw water was stopped, and first, sterilization treatment was performed as follows.

[0073] From the raw water tank 2, the raw water was supplied to the heat exchanger 3 by the pump 5 and heated to heated water. The obtained heated water was sent out to the supply pipe L1, and the opening degrees of the valve V1a and the valve V1b were adjusted respectively to branch in this supply pipe L1. The flow rates of the branched heated water were set such that the flow rate Q1 on the water treatment device side and the flow rate Q2 circulating through the first circulation pipe L3 to the raw water tank 2 were Q1:Q2 = 35:65.

[0074] Also, the heated water circulated to the water treatment device side had the valve V2a closed, the valve V2b opened, and the entire amount of it was circulated to the raw water tank 2 through the second circulation pipe L4.

[0075] This operation was repeated continuously until the raw water reached the desired sterilization temperature (80 °C). When the desired temperature was reached, the valve V1b was closed, and a sterilization treatment was performed for 30 minutes while circulating the heated water through the second circulation pipe L4.

[0076] (Comparative Example 1) A pharmaceutical water production system 51 having a raw water tank 2, a heat exchanger 3, a reverse osmosis membrane device (RO) 41, and an electro-deionization device (EDI) 42 in this order as shown in FIG. 5, and having a supply pipe L1, a supply pipe L2, and a second circulation pipe L4 branched therefrom, was prepared.

[0077] Note that although not shown in the figure, an ultraviolet irradiation device (UV) is provided in the pharmaceutical water production system 11 between the branch portion between the electro-deionization device 42 and the second circulation pipe L4 in the supply pipe L2. That is, this pharmaceutical water production system 51 is different from the pharmaceutical water production system 11 used in Example 1 only in that the first circulation pipe L3 is not provided.

[0078] Regarding this pharmaceutical water production system 51, first, city water was supplied to and stored in the raw water tank 2 as raw water. The supply of the raw water was stopped, and first, a sterilization treatment was performed as follows.

[0079] From the raw water tank 2, the raw water was supplied to the heat exchanger 3 by the pump 5 and heated to obtain heated water. The obtained heated water was sent to the supply pipe L1, circulated through the water treatment device, then the valve V2a was closed, the valve V2b was opened, and the entire amount of it was circulated to the raw water tank 2 through the second circulation pipe L4.

[0080] This operation was repeated continuously until the raw water reached the desired sterilization temperature (80 °C). When the desired temperature was reached, a sterilization treatment was performed for 30 minutes while circulating the heated water through the second circulation pipe L4.

[0081] In Example 1 and Comparative Example 1 described above, temperature sensors were provided at the outlet of the heat exchanger 3 and the outlet of the raw water tank 2 during the heat treatment, the temperature changes were measured over time, and the results are shown in Table 1 and FIG. 6 (Example 1) and Table 2 and FIG. 7 (Comparative Example 1). Here, the starting point of time (0 minutes) is the time when the sterilization method was started when the raw water began to be heated by the heat exchanger 3.

[0082]

Table 1

[0083]

Table 2

[0084] Incidentally, it took about 43 minutes in Example 1 and about 43 minutes in Comparative Example 1 to heat the temperature at the outlet of the heat exchanger 3 to 80°C. However, it took about 48 minutes in Example 1 and about 64 minutes in Comparative Example 1 to heat the temperature at the outlet of the raw water tank 2 to 80°C. That is, the difference between the time required to heat the temperature at the outlet of the heat exchanger 3 to 80°C and the time required to heat the temperature at the outlet of the raw water tank 2 to 80°C was about 5 minutes in Example 1 and about 16 minutes in Comparative Example 1. That is, it was found that in Example 1, the extra heating time for the water treatment device 4 was suppressed compared to Comparative Example 1.

[0085] Also, when the temperature at the outlet of the raw water tank 2 reached 80°C, the temperature at the outlet of the heat exchanger 3 was about 82°C in the example and about 92°C in Comparative Example 1. That is, from this point as well, it was found that in Example 1, the extra temperature rise for the water treatment device 4 was suppressed compared to Comparative Example 1.

[0086] From the above, it was found that in Example 1, the extra heat load on the water treatment device 4 was suppressed compared to Comparative Example 1, and thus the energy efficiency was also good. It was also found that the time required for the sterilization treatment could be shortened.

[0087] That is, according to the present embodiment, in the heating step of producing heated water, while circulating the heated water obtained by the heat exchanger to the raw water tank in the front stage of the treatment device and raising the temperature, it is possible to heat to a desired temperature in a shorter time and perform the sterilization treatment efficiently.

[0088] Further, according to the present embodiment, since a part of the heated water obtained by the heat exchanger is passed through the treatment device, the temperature of the heated water passed through the treatment device is gradually increased, so that the heat load on the treatment device is not excessively increased and the function degradation can be prevented.

Description of Reference Numerals

[0089] 1, 11, 51... Pharmaceutical water production system, 2... Raw water tank, 3... Heat exchanger, 4... Water treatment device, 5... Pump, L1, L2... Supply pipes, L3... First circulation pipe, L4... Second circulation pipe, V0, V1a, V1b, V2a, V2b... Valves, 41... Reverse osmosis membrane device (RO), 42... Electro-deionization device (EDI)

Claims

1. a water treatment device having at least one device selected from a reverse osmosis membrane device, an electrodeionization device, an activated carbon adsorption device, an ultrafiltration membrane device, and a mixed bed ion exchange device capable of removing impurities contained in the raw water discharged from the raw water tank; a heat exchanger disposed upstream of the water treatment device and capable of heating the raw water supplied from the raw water tank; and a first circulation pipe branching off from a supply pipe connected from the heat exchanger to the water treatment device and circulating a portion of the heated water heated in the heat exchanger to the raw water tank, The raw water discharged from the raw water tank is heated in the heat exchanger to produce heated water, The heated water is supplied to the water treatment device, and a part of the heated water is branched off to the first circulation pipe to circulate the heated water to the raw water tank; A sterilization method for a medical water production system, comprising adjusting a flow rate ratio (flow rate Q1:flow rate Q2) of the heated water to the supply piping and the flow rate Q2 to the first circulation piping to be 90:10 to 20:

80.

2. 2. The method for sterilizing a medical water producing system according to claim 1, wherein the heated water having passed through the water treatment device is circulated to the raw water tank through a second circulation piping.

3. 3. The sterilization method for a medical water producing system according to claim 1, further comprising the step of dispersing the circulated heated water into the raw water tank by a spray nozzle.

4. A medical water production process comprising: supplying raw water from a raw water tank to a water treatment device having at least one selected from a reverse osmosis membrane device, an electric deionization device, an activated carbon adsorption device, an ultrafiltration membrane device, and a mixed bed ion exchange device, and removing impurities contained in the raw water; a sterilization step of supplying heated water to the water treatment device; Alternate between The sterilization step includes: The raw water is heated in a heat exchanger to obtain the heated water, The heated water is supplied to the water treatment device from a supply pipe connected from the heat exchanger to the water treatment device, and a part of the heated water is branched from the supply pipe to a first circulation pipe to circulate the heated water to the raw water tank; The flow rate ratio (flow rate Q1:flow rate Q2) of the heated water to the supply pipe and the flow rate Q2 to the first circulation pipe is adjusted to 90:10 to 20:80; 2. A method for producing medical water comprising the steps of:

5. A method for producing medical water as described in Claim 4, wherein the sterilization process comprises circulating the heated water that has passed through the water treatment device to the raw water tank via a second circulation piping.

6. 6. The method for producing medical water according to claim 4 or 5, wherein the length of the first circulation pipe is 2 m or less.

7. 7. The method for producing medical water according to claim 4, wherein the axis of the first circulation pipe is arranged to extend vertically.

8. A method for producing medical water described in any one of claims 4 to 7, wherein the sterilization process further comprises dispersing the circulated heated water into the raw water tank using a spray nozzle.

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