Water for injection production system

Abstract

A system for producing water for injection that can reduce costs is provided. [Solution] The system comprises a purified water tank 2, a water for injection tank 3, a first UF device 11 and a second UF device 12 that filter purified water, and a supply flow path 5 that connects the second UF device 12 and the water for injection tank 3, and no tank for temporarily storing water for injection is provided between the first UF device 11 and the second UF device 12. Purified water is filtered in the order of the first UF device 11 and the second UF device 12 to produce water for injection, and the water for injection is supplied to the water for injection tank 3 via the supply flow path 5.

Description

[Technical Field]

[0001] The present invention relates to a system for producing water for injection from purified water. [Background technology]

[0002] Non-Patent Document 1 discloses a system for producing water for injection from purified water. Specifically, the system includes a first system in which a purified water tank and a first UF device are connected by a circulation flow path, and a second system in which a UF water tank and a second UF device are connected by a circulation flow path. Purified water is filtered by the first UF device to produce UF water, which is supplied to the UF water tank, and UF water is filtered by the second UF device to produce water for injection, which is stored in the water for injection tank. The first UF device and the second UF device each have a UF membrane and a filtering function that removes viable bacteria, endotoxins, and fine particles.

[0003] Because the UF water produced in the first system is temporarily stored in a UF water tank, the second system is less affected by the operating status of the first system. For example, the second system controls a pump to circulate UF water through the circulation flow path at a desired flow rate, but this control does not require consideration of the flow rate of UF water supplied from the first system, because the UF water is temporarily stored in the UF water tank. In this way, the first and second systems can be considered independent from a control perspective.

[0004] However, the installation of a UF water tank requires additional installation costs and space, and a device to sterilize the UF water tank is also required, which increases both initial and running costs. [Prior art documents] [Non-patent literature]

[0005] [Non-Patent Document 1] Tsuguo Sasaki and Osamu Shirakizawa (eds.), "Learn Pharmaceutical Water Systems from Scratch: From GMP-compliant Design to Manufacturing Management and Quality Control", Jiho Co., Ltd., November 2023, pp. 136-141 Summary of the Invention [Problem to be solved by the invention]

[0006] In view of the above circumstances, an object of the present invention is to provide a system for producing water for injection that can reduce costs. [Means for solving the problem]

[0007] One aspect of the present invention to achieve the above object is a water for injection manufacturing system that manufactures water for injection from purified water, comprising a purified water tank, a water for injection tank, a first UF device that filters purified water, a second UF device, and a supply flow path that connects the second UF device and the water for injection tank, wherein no tank for temporarily storing water for injection is provided between the first UF device and the second UF device, and the water for injection is manufactured by filtering purified water through the first UF device and then the second UF device, and is supplied to the water for injection tank via the supply flow path. [Effects of the Invention]

[0008] According to the present invention, a system for producing water for injection that can reduce costs is provided. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram of a water for injection manufacturing system. [Figure 2] FIG. 1 is a schematic diagram illustrating the manufacturing process of a system for manufacturing water for injection. [Figure 3] FIG. 1 is a schematic diagram illustrating a sterilization process of a water for injection manufacturing system. [Figure 4] 10 is a graph showing current values ​​and set values, and a graph showing control values. [Figure 5]4 is a flowchart showing the operation of the control system. [Figure 6] 4 is a flowchart showing the operation of the control system. [Figure 7] 4 is a flowchart showing the operation of the control system. [Figure 8] FIG. 10 is a schematic diagram illustrating the configuration of a modified example of a water for injection manufacturing system. DETAILED DESCRIPTION OF THE INVENTION

[0010] First Embodiment 1 is a schematic diagram of a water for injection manufacturing system according to this embodiment. The water for injection manufacturing system 1 of this embodiment is composed of a group of devices for manufacturing water for injection from purified water supplied from a purified water manufacturing apparatus 100.

[0011] The purified water production apparatus 100 is composed of a group of devices, not shown, such as activated carbon, a filter device, a heat exchanger, an EDI device, etc., and produces purified water from ordinary water. Such purified water production apparatus 100 is well known, so a detailed description thereof will be omitted.

[0012] The water for injection manufacturing system 1 includes a purified water tank 2 and a first UF device 11 connected by a first circulation flow path 10. The water for injection manufacturing system 1 further includes a water for injection tank 3 connected to the secondary side of the first UF device 11 via a second circulation flow path 20.

[0013] The purified water tank 2 is a tank that stores purified water supplied from the purified water production apparatus 100 and also stores purified water circulated without being filtered by the first UF device 11. A first circulation flow path 10 is connected to the bottom of the purified water tank 2, and the purified water stored in the purified water tank 2 is supplied to the first UF device 11 via the first circulation flow path 10. The first circulation flow path 10 is connected to the top of the purified water tank 2, and purified water is supplied from the first UF device 11. Although not specifically shown, the first circulation flow path 10 is connected to the bottom of the purified water tank 2 via an on-off valve. The on-off valve controls the supply and stop of purified water. The amount of purified water stored in the purified water tank 2 can be measured using a measuring device (not shown).

[0014] The water for injection tank 3 is a tank that stores water for injection produced by filtration in the second UF device 12. A supply flow path 5 is connected to the top of the water for injection tank 3. The water for injection produced in the second UF device 12 is supplied to the water for injection tank 3 through the supply flow path 5. The water for injection tank 3 is also connected to a use point, and the water for injection inside is supplied to the use point in accordance with demand at the use point. Although not specifically shown, a flow path that connects the water for injection tank 3 to the use point via an on-off valve is connected to the bottom of the water for injection tank 3. The on-off valve controls the supply and stop of the water for injection.

[0015] The first UF device 11 is a device that filters purified water using a crossflow method. The filter is a ceramic UF membrane or an organic UF membrane with a molecular weight cutoff of 6000 or more. The UF membrane is an ultrafiltration membrane. The first UF device 11 has a primary side and a secondary side sandwiching the filter, and the primary side is connected to the purified water tank 2 by a first circulation flow path 10. The secondary side of the first UF device 11 is connected to a connection flow path 4.

[0016] The second UF device 12 is a device similar to the first UF device 11. The second UF device 12 has a primary side and a secondary side with a filter in between, and the primary side is connected to the connection flow path 4 by a second circulation flow path 20. The secondary side of the second UF device 12 is connected to the supply flow path 5.

[0017] The first circulation flow path 10 is a flow path composed of pipes and fittings configured so that purified water flows in the following order: outlet of the purified water tank 2, inlet on the primary side of the first UF device 11, outlet on the primary side of the first UF device 11, and inlet of the purified water tank 2.

[0018] The second circulation flow path 20 is a flow path formed by piping, fittings, etc., configured so that purified water flows through the confluence A with the connecting flow path 4, the inlet on the primary side of the second UF device 12, the outlet on the primary side of the second UF device 12, and the confluence A in this order.

[0019] A first pump P1 and a first heat exchanger H1 are provided along the first circulation flow path 10. The first pump P1 is provided between the outlet of the purified water tank 2 and the inlet on the primary side of the first UF device 11. The first pump P1 pumps purified water from the purified water tank 2 to the first UF device 11 at a predetermined flow rate. The first heat exchanger H1 is provided between the outlet of the purified water tank 2 and the inlet on the primary side of the first UF device 11. Using a heat medium supply source (not shown), the first heat exchanger H1 heats or cools the purified water flowing from the first UF device 11 to the purified water tank 2 to a predetermined temperature.

[0020] A second pump P2, which does not have a heat exchanger, is provided midway along the second circulation flow path 20. The second pump P2 is provided between the junction A and the primary side inlet of the second UF device 12. The second pump P2 pumps the junction of the injection water supplied from the first UF device 11 and the injection water not filtered by the second UF device to the second UF device 12 at a predetermined flow rate.

[0021] A second heat exchanger H2 is provided in the supply flow path 5. The second heat exchanger H2 uses a heat medium supply source (not shown) to heat or cool the temperature of the water for injection supplied from the second UF device 12 to the water for injection tank 3 to a temperature set according to demand at the point of use.

[0022] The first circulation flow path 10 is provided with a first pressure gauge 31 between the first pump P1 and the first UF device 11. The first circulation flow path 10 is provided with a first drain D1 between the first pump P1 and the first UF device 11. The second circulation flow path 20 is provided with a third pressure gauge 33 between the second pump P2 and the second UF device 12. The second circulation flow path 20 is provided with a third drain D3 between the second pump P2 and the second UF device 12. The connection flow path 4 is provided with a second pressure gauge 32, a first flow meter 41, a first organic carbon concentration meter 51, and a second drain D2. The supply flow path 5 is provided with a fourth pressure gauge 34, a second flow meter 42, a second organic carbon concentration meter 52, and a fourth drain D4. When the first pressure gauge 31 to the fourth pressure gauge 34 are not distinguished from one another, they are referred to as pressure gauges 30. The pressure gauges 30 are devices that measure the pressure of purified water or water for injection at the locations where they are attached. When there is no need to distinguish between the first flow meter 41 and the second flow meter 42, they will be referred to as the flow meter 40. The flow meter 40 is a device that measures the flow rate of purified water or water for injection at the location where it is attached. When the first organic carbon concentration meter 51 and the second organic carbon concentration meter 52 are not distinguished from each other, they are referred to as the organic carbon concentration meter 50. The organic carbon concentration meter is a device that measures the total amount of carbon that constitutes the organic matter present in purified water or water for injection at the location where it is installed. The total amount is one indicator of the degree of contamination of the water.

[0023] The SIP apparatus 60 is a sterilization apparatus for performing SIP (SIP) on the first UF apparatus 11 and the second UF apparatus 12. For example, the SIP apparatus 60 is composed of a supply source of the sterilizing fluid used in the stationary sterilization, a device for pressure-feeding the sterilizing fluid (a device that pressure-feeds using a pump or gas), a treatment device for discarding or reusing the sterilizing fluid after the stationary sterilization is completed, a valve for controlling the flow of the sterilizing fluid, piping and joints through which the sterilizing fluid flows, a control device for controlling various devices to start and stop pressure-feeding, etc. The sterilizing fluid is hot water or steam obtained by heating purified water or the like.

[0024] The SIP device 60 is connected to a junction B via a supply line S1. The junction B is a portion of the first circulation flow path 10 between the first UF device 11 and the first heat exchanger H1. A sterilizing fluid is supplied from the SIP device 60 to the upstream side of the first UF device 11 via the supply line S1. The SIP device 60 is also connected to a junction C via a supply line S2. The junction C is a portion of the second circulation flow path 20 between the downstream side of the second UF device 12 and the junction A. A sterilizing fluid is supplied from the SIP device 60 to the upstream side of the second UF device 12 via the supply line S2.

[0025] The injection water manufacturing system 1 is provided with valves (not shown) as appropriate to realize the flows of purified water, injection water, and sterilization fluid as described below. The opening and closing of these valves can be controlled by a control device.

[0026] Although not specifically shown, the water for injection manufacturing system 1 is equipped with a control device that controls the above-mentioned component devices. The control device is, for example, a programmable logic controller (PLC). The control device is capable of obtaining, as electrical signals, the pressure detected by the measuring device and pressure gauge 30 provided in the purified water tank 2, the flow rate detected by the flow meter, and the amount of carbon detected by the organic carbon concentration meter. Based on this information, the control device performs control to execute the following processes. Manufacturing process: A process for manufacturing water for injection from purified water supplied from the purified water manufacturing apparatus 100 Sterilization process: The process of sterilizing (SIP) the water for injection manufacturing system 1.

[0027] The manufacturing process executed by the water for injection manufacturing system 1 will be described using Figure 2. In the manufacturing process, purified water is supplied to the purified water tank 2 and the primary side inlet of the first UF device 11, and the first pump P1 is operated so that the purified water that has not been filtered by the filter of the first UF device 11 returns to the first heat exchanger H1 and the purified water tank 2. In the first UF device 11, the purified water is filtered by the filter. As the purified water passes from the primary side to the secondary side of the filter, live bacteria and the like are removed from the purified water, and it becomes water for injection.

[0028] In order to circulate purified water between the purified water tank 2 and the first UF device 11 in this manner, valves (not shown) are provided at various locations in the first circulation flow path 10 and are opened and closed as appropriate by the control device. Furthermore, when the control device detects via a measuring device that the amount of purified water stored in the purified water tank 2 has fallen below a predetermined amount, it causes the purified water production device 100 to supply purified water to the purified water tank 2. This maintains a state in which the purified water tank 2 contains at least the predetermined amount of water.

[0029] The water for injection produced by the first UF device 11 is sent to the second circulation flow path 20 via the connecting flow path 4. The water for injection is supplied to the junction A and the inlet on the primary side of the second UF device 12, and the second pump P2 is operated so that the water for injection that has not been filtered by the filter of the second UF device 12 returns to the junction A. In the second UF device 12, the water for injection is filtered by the filter. Although it is already water for injection, any remaining viable bacteria are removed as it passes from the primary side to the secondary side of the filter, resulting in water for injection from which viable bacteria have been more reliably removed. The water for injection produced by the second UF device 12 is supplied to the water for injection tank 3 via the supply flow path 5.

[0030] The first pump P1 and the second pump P2 are controlled by a control device so as to circulate purified water or water for injection at a predetermined flow rate through the first circulation flow path 10 and the second circulation flow path 20. The detailed control will be described later.

[0031] In the manufacturing process, it is important to ensure that the quality of the water for injection is maintained. Water quality is ensured based on the values ​​detected by the pressure gauge 30 and the organic carbon concentration meter 50. For example, if the values ​​detected by the pressure gauge 30 and the organic carbon concentration meter 50 are within a certain range from a predetermined reference value, it is determined that the water for injection meets the required quality. To support this water quality monitoring, the control device displays the values ​​detected by the pressure gauge 30 and the organic carbon concentration meter 50 and the reference value on a display device such as a touch panel. The control device also displays whether the detected value is within a certain range from the reference value and issues a warning if it is not within the certain range. Such reference values ​​are set individually for each of the first pressure gauge 31 to the fourth pressure gauge 34 and the first organic carbon concentration meter 51 to the second organic carbon concentration meter 52.

[0032] More specifically, a first pressure gauge 31 and a second pressure gauge 32 are provided before and after the first UF device 11, and a third pressure gauge 33 and a fourth pressure gauge 34 are provided before and after the second UF device. If the detected values ​​of the first pressure gauge 31 and the second pressure gauge 32 are both within a certain range from a reference value, it can be said that purified water is being supplied to the filter of the first UF device 11 at an appropriate pressure, and it can be determined that filtration is occurring normally. Similarly, if the detected values ​​of the third pressure gauge 33 and the fourth pressure gauge 34 are both within a certain range from a reference value, it can be said that purified water is being supplied to the filter of the second UF device 12 at an appropriate pressure, and it can be determined that filtration is occurring normally. Using such pressure gauges 30, it can be determined that the quality of the filtered water for injection is guaranteed for each of the first UF device 11 and the second UF device 12.

[0033] The same quality assurance can be said for the organic carbon concentration meter 50. That is, if the detection value of the first organic carbon concentration meter 51 is within a certain range from the reference value, it can be said that purified water is being supplied to the filter of the first UF device 11 at an appropriate pressure, and it can be determined that filtration is occurring normally. If the detection values ​​of the second organic carbon concentration meter 52 are both within a certain range from the reference value, it can be said that purified water is being supplied to the filter of the second UF device 12 at an appropriate pressure, and it can be determined that filtration is occurring normally. With such an organic carbon concentration meter 50, it can be determined that the quality of the water for injection after filtration is assured for each of the first UF device 11 and the second UF device 12.

[0034] The manufacturing process executed in the water for injection manufacturing system 1 will be described with reference to Figure 3. The control device causes the SIP device 60 to supply the sterilizing fluid to the first UF device 11 and the second UF device 12. Specifically, the sterilizing fluid is circulated from the SIP device 60 to the upstream side of the first UF device 11 via the supply line S1, the junction B, and the first circulation flow path 10. A portion of the sterilizing fluid passes through the filter and is discharged to the outside via the connecting flow path 4 and the second drain D2, or is returned to the SIP device 60. The remainder of the sterilizing fluid is discharged to the outside from the first UF device 11 via the first circulation flow path 10 and the first drain D1, or is returned to the SIP device 60.

[0035] The control device also circulates the sterilizing fluid from the SIP device 60 via the supply line S2, the junction C, and the second circulation flow path 20 to the upstream side of the second UF device 12. A portion of the sterilizing fluid passes through the filter and is discharged to the outside via the supply flow path 5 and the fourth drain D4, or is returned to the SIP device 60. The remainder of the sterilizing fluid is discharged to the outside from the second UF device 12 via the second circulation flow path 20 and the third drain D3, or is returned to the SIP device 60.

[0036] Valves (not shown) are provided at various locations in the first circulation flow path 10 so that the sterilizing fluid can be supplied from the SIP device 60 to the first UF device 11 and discharged to the outside or returned to the SIP device 60, and these valves are opened and closed as appropriate by a control device. Similarly, valves (not shown) are provided at various locations in the second circulation flow path 20 so that the sterilizing fluid can be supplied from the SIP device 60 to the second UF device 12 and discharged to the outside or returned to the SIP device 60, and these valves are opened and closed as appropriate by a control device. In the example shown in the figure, only the first UF device 11 and the second UF device 12 are targeted for sterilization, but other devices, such as the entire first circulation flow path 10, the entire second circulation flow path 20, the first pump P1, and the second pump P2, may also be targeted for sterilization.

[0037] The injection water manufacturing system 1 configured as described above produces injection water by filtering purified water stored in the purified water tank 2 through the first UF device 11 and the second UF device 12 in that order. No tank for temporarily storing injection water is provided between the first UF device 11 and the second UF device 12. Such an injection water manufacturing system 1 eliminates the installation costs and installation area required for providing such a tank, and also eliminates the need for a device for sterilizing the tank. In other words, the initial cost and running cost required for a tank provided between the first UF device 11 and the second UF device 12 are unnecessary, thereby realizing a cost-effective injection water manufacturing system 1.

[0038] Sterilization of UF membranes is essential to ensure the quality of water for injection. However, because UF membranes are damaged by the heat of the sterilizing fluid, there is a demand for minimizing sterilization. For example, conventional technology includes a two-stage UF device, but the SIP device is configured to sterilize only the latter UF device. In other words, damage to the UF membrane is avoided by not performing SIP on the former UF device. Since SIP is not performed on the former UF device, it can be said that water for injection is essentially produced by the latter UF device. Therefore, if there is a malfunction in the latter UF device, the water produced by the former UF device will be supplied as water for injection, but the quality of the water for injection cannot be said to be guaranteed.

[0039] Meanwhile, the water for injection manufacturing system 1 is equipped with a SIP device 60 that sterilizes the first UF device 11 and the second UF device 12. Because both the first UF device 11 and the second UF device 12 are sterilized, the quality of the water for injection can be reliably guaranteed. In other words, even if a malfunction occurs in one of them, the other is sterilized and in a normal state, so water for injection of guaranteed quality can be supplied to the water for injection tank 3 and points of use.

[0040] In the prior art, as described above, water for injection is essentially produced by a UF device in the subsequent stage, and therefore no particular consideration has been given to providing a sensor for checking the quality of the water for injection after the UF device in the preceding stage. However, the water for injection manufacturing system 1 is equipped with a pressure gauge 30 and an organic carbon concentration meter 50 as sensors for measuring the properties of the water for injection produced by the first UF device 11 and the second UF device 12, and the detected values ​​are displayed on a display means such as a touch panel. This makes it possible to confirm that the quality of the water for injection is guaranteed for both the first UF device 11 and the second UF device 12. Note that the display means may be a touch panel connected to the control device, or may be the screen of a smartphone capable of communicating with the control device, or a display connected to an information processing device such as a personal computer.

[0041] The injection water production system 1 has a first UF device 11 of a crossflow type, with the primary side connected to the purified water tank 2 via a first circulation flow path 10 and the secondary side connected to a second UF device 12. The number of first UF devices 11 is not limited to one, and multiple devices may be used. When multiple first UF devices are used, they are connected in parallel so that the injection solution is distributed to the primary side of each first UF device. The injection solution discharged from the secondary side is then supplied to the second UF device.

[0042] In the injection water manufacturing system 1, the second UF device 12 is of a crossflow type, and its primary side is connected to the first UF device 11 via a second circulation flow path 20, and its secondary side is connected to the injection water tank 3 via a supply flow path 5. The number of second UF devices 12 is not limited to one, and multiple devices may be used. When multiple second UF devices are used, they are connected in parallel so that the injection solution is distributed to the primary side of each second UF device. The injection solution discharged from the secondary side is then supplied to the injection water tank 3 via the supply flow path 5.

[0043] In the injection water manufacturing system 1, the first circulation flow path 10 is provided with a first heat exchanger H1, but the second circulation flow path 20 is not provided with a heat exchanger. Because there is no need to provide a heat exchanger in the second circulation flow path 20, the number of SIPs that are required can be reduced, and the cost of SIP can be reduced. Furthermore, the temperature of the injection water manufactured in the second UF device 12 can be adjusted to a desired temperature by the first heat exchanger H1 provided in the first circulation flow path 10.

[0044] <Flow Control> The control of the flow rate of purified water or water for injection executed by the control device will be described using Figures 4 to 7. Figure 4(a) is a graph showing the current value and the set value, and Figure 4(b) is a graph showing the control value. Figures 5 to 7 are flowcharts showing the operation of the water for injection manufacturing system 1. The horizontal axes of Figures 4(a) and 4(b) represent time. The vertical axis of Figure 4(a) represents the current value, and the vertical axis of Figure 4(b) represents the control value. The following description will focus on the control of the inverter drive frequency for maintaining purified water or water for injection at the set flow rate, with the current value being interpreted as the current flow rate, the set value as the set flow rate, and the control value as the control frequency.

[0045] Although not specifically illustrated in FIGS. 1-3, inverters are provided for each of the first pump P1 and the second pump P2. The control device is configured with a set value (set flow rate) corresponding to the current flow rate of the first flow meter 41, reads the current value (current flow rate) from the first flow meter 41, and appropriately changes the control value (control frequency) provided to the inverter of the first pump P1 so that the current value becomes the set value. Similarly, the control device is configured with a set value (set flow rate) corresponding to the current flow rate of the second flow meter 42, reads the current value (current flow rate) from the second flow meter 42, and appropriately changes the control value (control frequency) provided to the inverter of the second pump so that the current value becomes the set value. The control device controls the first pump P1 to pump purified water or water for injection at the set flow rate, as described below. Similar control is performed for the second pump P2.

[0046] Control for setting the current value of purified water to the set value is classified into four periods: initial start-up, emergency, stable, and unstable. First, the initial start-up period will be explained.

[0047] The initial start-up refers to the time (T0 to T1) from when the injection water manufacturing system 1 is started until a predetermined time. Specifically, as shown in Figure 4(a), it is performed when the current value is significantly different from the set value. Furthermore, the start-up referred to here not only refers to the start-up of the injection water manufacturing system 1 to produce purified water, but also includes the start-up of SIP.

[0048] First, when the process of producing purified water in the water for injection manufacturing system 1 is completed, the control device stores the control value at that time in memory as the control value at the previous completion. At this time, the control value in a stable state, which will be described later, is stored as the control value at the previous completion. When the water for injection manufacturing system 1 is started for the first time, an appropriate value is set in advance as the control value at the previous completion, because no liquid delivery process has yet been completed.

[0049] When the manufacturing process is started next time (T0), the control device 50 calls the control value at the time of the previous end (step S1 in FIG. 5), and calculates an amount (hereinafter referred to as an increment) by dividing the control value at the time of the previous end by a predetermined number (5 in the example in FIG. 4) (step S2 in FIG. 5). Next, the control device 50 calculates a control value by the increment until it reaches the control value at the time of the previous end during a predetermined time (T1) after the start (step S3 in FIG. 5).

[0050] As shown in Figure 4(b), during the initial startup, the control value increases in stages between T0 and T1. This increase is the control value at the end of the previous run divided by 5, so at the end of the initial startup, the control value is the control value at the end of the previous run.

[0051] As shown in Figure 4(a), during the initial start-up, the control value is increased in stages. In other words, the drive frequency of the inverter increases in stages, allowing the current value to quickly rise to near the set value. Also, during the initial start-up, the drive frequency is increased in stages, and the final point is the control value at the end of the previous process. The control value at the end of the previous process is the value when the current value was nearly equal to the set value in the previous liquid transfer process. Therefore, when the initial start-up is complete, although there is a slight overshoot, the current value can quickly stabilize at the set value.

[0052] Furthermore, the control value required to achieve a specific set value is not necessarily constant, but fluctuates, for example, due to changes in the environment surrounding the water for injection manufacturing system 1 (such as seasonal fluctuations). In the present invention, the control value at the previous end is updated for each liquid delivery process, and at initial start-up, the control value is increased in stages to reach the control value at the previous end. This makes it possible to adjust to the changes in the environment surrounding the water for injection manufacturing system 1 and to set the optimal control value at the completion of initial start-up.

[0053] Next, an emergency will be described. An emergency occurs when the current value exceeds the upper limit (a value greater than the set value ±Δ) (T6 to T7). If the current value is greater than the predetermined upper limit after a predetermined time has elapsed since startup (after T1), the control device determines that an emergency has occurred and reduces the control value (step S5 in FIG. 5).

[0054] When the current value exceeds the upper limit (T6 in Figure 4(b)), the control value is set to 90% (Figure 4(a)). This lowers the inverter drive frequency, so as shown in Figure 4(a), the current value decreases and, after a predetermined time has passed (T7), it falls below the upper limit. In this way, even if an emergency occurs that causes the upper limit to be exceeded for some reason, it can be detected and the flow rate reduced, thereby resolving the emergency.

[0055] The method for decreasing the inverter control value between T6 and T7 may involve decreasing the control value once, or may involve decreasing the control value multiple times at regular intervals. Furthermore, when the current value exceeds the upper limit, the inverter control value may be decreased immediately, or may be decreased after a certain time has elapsed.

[0056] Next, the stable state will be described. The stable state refers to the state when the current value is within ±Δ of the set value (+Δ is called the increase range and −Δ is called the decrease range) (T3 to T4, T5 to T6). If the current value is greater than or less than the set value after a predetermined time has elapsed since the injection water manufacturing system 1 was started, the control device increases or decreases the control value by a first predetermined amount. In detail, the process is carried out as follows.

[0057] First, when there is no emergency (Step S4 in FIG. 5; No), the control device determines whether the current value is greater than the set value (Step S6 in FIG. 5). If the current value is greater than the set value (Step S6 in FIG. 5; Yes), the control device decreases the control value by a first predetermined amount (Step S7 in FIG. 6).

[0058] As shown in Figure 4(a), when the current value exceeds the set value during stability (T10), a first predetermined amount (for example, 0.3% of the control value at that time) is subtracted from the control value as shown in Figure 4(b). This causes the drive frequency of the inverter to slightly decrease, so as shown in Figure 4(a), after a certain time has passed since the control value was subtracted (T11), the current value decreases and becomes equal to or close to the set value.

[0059] Furthermore, if the current value is equal to or less than the set value (Step S6 in FIG. 5; No), the control device increases the control value by a first predetermined amount (Step S8 in FIG. 7). Note that the first predetermined amount when adding (Step S7 in FIG. 6) may be different from the first predetermined amount when subtracting (Step S8 in FIG. 7).

[0060] As shown in Fig. 4(a), when the current value is equal to or less than the set value (for example, T12) during stability, the control value is increased by a first predetermined amount (for example, 0.2% of the control value at that time) (Fig. 7, step S8) as shown in Fig. 4(b). This causes the drive frequency of the inverter to increase slightly, so as shown in Fig. 4(a), after a certain time has elapsed since the control value was increased (for example, T13), the current value increases and becomes equal to or close to the set value.

[0061] In this way, by changing the drive frequency of the inverter, it is possible to maintain a stable state in which the current value is approximately equal to the set value.

[0062] In addition, the method of increasing or decreasing the inverter control value during stability may involve increasing or decreasing the control value once, or may involve increasing or decreasing the control value multiple times at regular intervals. Furthermore, when the current value exceeds the set value, the inverter control value may be increased or decreased immediately, or may be increased or decreased after a certain time has elapsed.

[0063] Next, we will explain the unstable state. The unstable state refers to a state where the current value is larger or smaller than the set value ±Δ (T2 to T3, T4 to T5). If the current value is larger or smaller than the set value ±Δ after a predetermined time has elapsed since the manufacturing plant was started, the control device increases or decreases the control value by a second predetermined amount. In detail, the process is performed as follows. Note that the second predetermined amount is larger than the first predetermined amount.

[0064] First, the control device determines whether the current value is greater than the set value + Δ (step S9 in FIG. 6). If the current value is equal to or less than the set value + Δ (step S9 in FIG. 6; No), the process returns to step S4 in FIG. 5. On the other hand, if the current value is greater than the set value + Δ (step S9 in FIG. 6; Yes), the control value is decreased by a second predetermined amount (for example, 3.0% of the control value at that time) (step S10 in FIG. 6). If the current value is equal to or greater than the set value + Δ (step S11 in FIG. 6; No), the control device is still unstable, so it waits for a certain period of time and then executes the process of step S10. If the current value is smaller than the set value + Δ (step S11 in FIG. 6; Yes), the control device has entered a stable state, so it returns to the process from step S4.

[0065] As shown in Figure 4(a), when the current value exceeds the set value + Δ (T4) during instability, a second predetermined amount (for example, 3.0% of the control value at that time) is subtracted from the control value as shown in Figure 4(b). This lowers the drive frequency of the inverter, and as shown in Figure 4(a), after a certain time has passed since the control value was subtracted (T5), the current value decreases significantly and approaches a stable state.

[0066] The control device also determines whether the current value is smaller than the set value -Δ (step S12 in FIG. 7). If the current value is equal to or greater than the set value -Δ (step S12 in FIG. 7; No), the process returns to step S4 in FIG. 5. On the other hand, if the current value is smaller than the set value -Δ (step S12 in FIG. 7; Yes), the control device increases the control value by a second predetermined amount (step S13 in FIG. 7). If the current value is equal to or smaller than the set value -Δ (step S14 in FIG. 7; No), the control device is still unstable, so it waits for a certain period of time and then executes the process of step S13. If the current value is larger than the set value -Δ (step S14 in FIG. 7; Yes), the control device has reached a stable state, so it returns to the process from step S4. Note that the second predetermined amount used during addition (step S13 in FIG. 7) may be different from the second predetermined amount used during subtraction (step S10 in FIG. 6).

[0067] As shown in Figure 4(a), when the current value is smaller than the set value -Δ (T2) during instability, the control value is increased by a second predetermined amount (for example, 2.0% of the control value at that time) as shown in Figure 4(b). This lowers the drive frequency of the inverter, so as shown in Figure 4(a), after a certain time has elapsed since the control value was increased (T3), the current value increases significantly and approaches a stable state.

[0068] In this way, by changing the drive frequency of the inverter, even if the current value becomes unstable, it can be made stable.

[0069] In addition, the method of increasing or decreasing the inverter control value during instability may involve increasing or decreasing the control value once, or may involve increasing or decreasing the control value multiple times at regular intervals. Furthermore, when the current value exceeds the set value ±Δ, the inverter control value may be increased or decreased immediately, or may be increased or decreased after a certain time has elapsed.

[0070] The water for injection manufacturing system 1 executes control to increase or decrease the control value by a predetermined amount so that the current value becomes the set value, as shown in stable, unstable, and emergency situations. That is, the purified water circulating through the first circulation flow path 10 and the water for injection circulating through the second circulation flow path 20 are maintained at a set flow rate. Therefore, water for injection can be supplied from the first UF device 11 to the second UF device 12 at a stable flow rate, without the need to provide a tank between the first UF device 11 and the second UF device 12 to temporarily store the water for injection.

[0071] <Variations> The above-described system for producing water for injection 1 includes a second circulation flow path 20 that connects the inlet and outlet on the primary side of the second UF device 12, and water for injection that has not been filtered by the second UF device 12 is supplied again to the second UF device 12 via the second circulation flow path 20. However, the system is not limited to this embodiment, and as shown in FIG. 8 , a third circulation flow path 70 may be provided to return water for injection that has not been filtered by the second UF device to the purified water tank 2.

[0072] Furthermore, although not specifically shown, a fourth circulation flow path may be provided that branches off from the supply flow path 5 subsequent to the second UF device 12 and connects to the purified water tank 2. When the water for injection tank 3 cannot accept the water for injection, for example when the water for injection tank 3 is full, the water for injection can be returned to the purified water tank 2. This allows the water for injection to continue circulating through the first circulation flow path 10 and the second circulation flow path 20, thereby preventing sanitation problems caused by water stagnation.

[0073] Other Embodiments The above describes one embodiment of the present invention. However, the present invention is not limited to the above embodiment, and additions, omissions, substitutions, and other modifications of the configuration are possible within the scope that does not deviate from the spirit of the present invention.

[0074] For example, while the above embodiment has a two-stage configuration consisting of a first UF device and a second UF device, the present invention is not limited to this configuration. That is, the system for producing water for injection may have three or more stages of UF devices, with an additional UF device provided after the second UF device.

[0075] Although one SIP device 60 is provided to sterilize the first UF device 11 and the second UF device 12, the configuration is not limited to this. For example, a SIP device 60 may be provided for each of the first UF device 11 and the second UF device.

[0076] Although the pressure meter 30 and the organic carbon concentration meter 50 are used as sensors for measuring the properties of the water for injection, the sensors are not limited to these. Other sensors such as a turbidity meter and a conductivity meter may also be used. [Explanation of symbols]

[0077] 1...water for injection production system, 2...purified water tank, 3...water for injection tank, 4...connecting flow path, 5...supply flow path, 10...first circulation flow path, 11...first UF device, 12...second UF device, 20...second circulation flow path, 30...pressure gauge, 40...flow meter, 50...organic carbon concentration meter, 60...SIP device, 70...third circulation flow path, 100...purified water production device

Claims

1. 1. A water for injection manufacturing system for manufacturing water for injection from purified water, A purified water tank; a water for injection tank; a first UF device and a second UF device for filtering purified water; a supply flow path connecting the second UF device and the water for injection tank; a first pump for delivering purified water to the first UF device; a second pump for delivering water for injection to the second UF device; a flow rate detecting means for detecting a flow rate of the injection solution supplied from the first UF device to the second UF device and a flow rate of the injection solution supplied from the second UF device to the injection water tank; an inverter for changing a drive frequency of the first pump and the second pump; a control device that adjusts the drive frequency according to a control value for setting the drive frequency of the inverter; There is no tank for temporarily storing water for injection between the first UF device and the second UF device, filtering purified water through the first UF device and the second UF device in this order to produce water for injection, and supplying the water for injection to the water for injection tank via the supply flow path; The control device increases or decreases the control value by a predetermined amount so that the current flow rate, which is the current value obtained by the flow rate detection means, becomes a predetermined set flow rate. A system for producing water for injection.

2. 2. The system for producing water for injection according to claim 1, and a SIP device for sterilizing the first UF device and the second UF device. A system for producing water for injection.

3. 3. The system for producing water for injection according to claim 2, a sensor for measuring the properties of the water for injection produced by the first UF device and the second UF device; A display means for displaying the detected value of the sensor is provided. A system for producing water for injection.

4. 2. The system for producing water for injection according to claim 1, The first UF device is a cross-flow type, and its primary side is connected to the purified water tank via a first circulation flow path, and its secondary side is connected to the second UF device. A system for producing water for injection.

5. 2. The system for producing water for injection according to claim 1, The second UF device is of a cross-flow type, and its primary side is connected to the first UF device via a second circulation flow path, and its secondary side is connected to the water for injection tank via the supply flow path. A system for producing water for injection.

6. 6. The system for producing water for injection according to claim 5, a heat exchanger is provided in a flow path connecting the first UF device and the purified water tank; The second circulation flow path is not provided with a heat exchanger. A system for producing water for injection.

7. 2. The system for producing water for injection according to claim 1, The control device When the operation is finished, the control value is stored as the control value at the time of the previous end. During a predetermined time from the start of operation, the control value is increased by a predetermined amount until it reaches the control value at the time of the previous end, The predetermined amount is an amount obtained by dividing the control value at the time of the previous termination by a predetermined number. A system for producing water for injection.

8. 8. The system for producing water for injection according to claim 7, The control device If the current flow rate is greater than the set flow rate, subtract a first predetermined amount from the control value; If the current flow rate is smaller than the set flow rate, the control value is increased by a first predetermined amount. A system for producing water for injection.

9. 9. The system for producing water for injection according to claim 8, A predetermined increase or decrease amount is set for the set flow rate, The control device, after a predetermined time has elapsed since the start of operation, If the current flow rate is greater than the set flow rate plus the increase amount, the control value is decreased by a second predetermined amount greater than the first predetermined amount; If the current flow rate is smaller than the value obtained by subtracting the decrease amount from the set flow rate, the control value is increased by a second predetermined amount that is larger than the first predetermined amount. A system for producing water for injection.

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