JP7751674B2 - Water treatment device and method for operating same - Google Patents

Description

The present invention relates to a water treatment device and its operating method.

In recent years, in order to achieve energy efficiency and economic efficiency, ultrafiltration (UF) membrane devices have been used instead of distillers to produce pure water (such as purified water and water for injection) for use in pharmaceutical manufacturing. In such pure water production systems, sterilization treatment is periodically performed using high-temperature steam (e.g., 121°C or higher) to sterilize the system in order to prevent the growth of bacteria and microorganisms. However, introducing high-temperature steam into the UF membrane device can cause deterioration of the UF membrane. Therefore, methods have recently been proposed for suppressing deterioration of UF membranes due to steam sterilization treatment (see, for example, Patent Document 1).

Patent No. 7365479

In pure water production systems equipped with UF membrane devices, in order to prevent deterioration or damage to the UF membranes due to a sudden rise in temperature, a preheating process is performed by circulating hot water within the system before steam sterilization, thereby raising the temperature within the system to a predetermined level. However, steam is typically introduced into the pure water production system from a predetermined position within the system, and the introduction range is gradually expanded. Therefore, particularly when multiple UF membrane devices are installed, the time it takes for steam to reach UF membrane devices farther away from the steam introduction position after hot water is discharged is inevitably longer. Air cooling occurs during this time, which may expose the device to a sudden rise in temperature when steam is subsequently introduced.

The object of the present invention is to provide a water treatment device and an operating method thereof that suppresses deterioration and damage to ultrafiltration membranes associated with steam sterilization.

In order to achieve the above-mentioned object, the water treatment device of the present invention comprises a plurality of ultrafiltration membrane devices, each having at least one ultrafiltration membrane module, a steam introduction means for introducing steam in parallel to the plurality of ultrafiltration membrane devices, a shut-off means provided in a connection line connecting a first ultrafiltration membrane device and a second ultrafiltration membrane device among the plurality of ultrafiltration membrane devices, for shutting off the flow of steam in the connection line, at least one discharge line connected to the connection line for discharging the shut-off steam to the outside, and at least one temperature sensor provided in at least one discharge line .

The method for operating a water treatment device of the present invention is a method for operating a water treatment device having a plurality of ultrafiltration membrane devices, each having at least one ultrafiltration membrane module, and includes the steps of: introducing steam into the plurality of ultrafiltration membrane devices in parallel and sterilizing the plurality of ultrafiltration membrane devices with the steam; and, when introducing steam into the plurality of ultrafiltration membrane devices, introducing steam into a connection line connecting a first ultrafiltration membrane device and a second ultrafiltration membrane device among the plurality of ultrafiltration membrane devices and sterilizing the connection line with the steam. The shutoff means includes switching between blocking the flow of steam from the second ultrafiltration membrane device to the connecting line while allowing steam to flow from the first ultrafiltration membrane device to the connecting line and discharging the steam to the outside through at least one discharge line connected to the connecting line, and blocking the flow of steam from the first ultrafiltration membrane device to the connecting line while allowing steam to flow from the second ultrafiltration membrane device to the connecting line and discharging the steam to the outside through at least one discharge line, based on the detection value of at least one temperature sensor provided in at least one discharge line .

The present invention can suppress deterioration and damage to ultrafiltration membranes that occur during steam sterilization.

1 is a schematic configuration diagram of an apparatus for preparing water for injection according to a first embodiment. 1 is a schematic configuration diagram of an ultrafiltration membrane device according to a first embodiment. FIG. 10 is a schematic configuration diagram showing a modified example of the apparatus for preparing water for injection according to the first embodiment. FIG. 10 is a schematic diagram illustrating the configuration of an apparatus for preparing water for injection according to a second embodiment. FIG. 10 is a schematic diagram illustrating the configuration of an apparatus for preparing water for injection according to a third embodiment.

Embodiments of the present invention will be described below with reference to the drawings. This specification illustrates an apparatus for producing pure water used in pharmaceutical manufacturing, specifically, an apparatus for producing water for injection by treating purified water, as an example of the water treatment device of the present invention. However, the present invention is not limited to this. This specification also illustrates an example in which the apparatus for producing water for injection has two ultrafiltration (UF) membrane devices, each of which has three UF membrane modules. However, the present invention is not limited to this. The number of UF membrane devices constituting the apparatus for producing water for injection may be three or more, and the number of UF membrane modules constituting each UF membrane device may be two or less or four or more. Furthermore, multiple UF membrane devices may each have a different number of UF membrane modules. In this specification, purified water refers to water obtained by purifying ordinary water through ion exchange, reverse osmosis (RO), ultrafiltration (UF), or a combination thereof. Water for injection refers to purified water or water that has undergone appropriate pretreatment and is treated by distillation or ultrafiltration (RO/UF) to conform to pyrogen (endotoxin) testing and viable bacteria testing. Examples of such purified water and water for injection include those specified in the Japanese Pharmacopoeia.

(First embodiment)
Fig. 1 is a schematic diagram of an apparatus for preparing water for injection according to a first embodiment of the present invention. Fig. 2 is a schematic diagram of an ultrafiltration membrane device that constitutes the apparatus for preparing water for injection according to this embodiment. Note that the configurations of the apparatus for preparing water for injection and the ultrafiltration membrane device shown in the drawings are merely examples and do not limit the present invention, and needless to say can be changed as appropriate depending on the purpose, application, and required performance of the apparatus.

The water for injection production apparatus 1 is an apparatus that produces water for injection by sterilizing purified water (the water to be treated) through ultrafiltration, and includes a purified water tank 2, a first UF membrane device 10, and a second UF membrane device 20.

The first UF membrane device 10 and the second UF membrane device 20 each have a UF membrane that separates the water to be treated into permeate and concentrate. They are connected in series so that the permeate separated by the first UF membrane device 10 is supplied to the second UF membrane device 20 as the water to be treated. Connecting the first UF membrane device 10 and the second UF membrane device 20 in series not only produces treated water (water for injection) of better water quality, but also provides a fail-safe function in case the UF membrane of the first UF membrane device 10 is damaged. The detailed configuration of the UF membrane devices 10 and 20 will be described later. Although not described in detail here, water quality detection means such as a conductivity meter, total organic carbon (TOC) meter, particle meter, microorganism counter, or endotoxin counter may be installed near the outlet of each UF membrane device 10 and 20 to check the quality of the resulting permeate.

Connected to the first UF membrane device 10 are a first water supply line L1 that supplies purified water from the purified water tank 2 to the first UF membrane device 10, a second water supply line (supply line) L2 that passes permeate water from the first UF membrane device 10 (hereinafter also referred to as "primary permeate water") and supplies it to the second UF membrane device 20, and a primary concentrate line L3 that passes concentrated water from the first UF membrane device 10 (hereinafter also referred to as "primary concentrate water") and returns it to the purified water tank 2. Connected to the second UF membrane device 20 are a water supply line L4 that passes permeate water from the second UF membrane device 20 (hereinafter also referred to as "secondary permeate water") and supplies it to a water tank for injection (not shown) as water for injection, and a secondary concentrate line L5 that passes concentrated water from the second UF membrane device 20 (hereinafter also referred to as "secondary concentrate water") and returns it to the purified water tank 2. Although not shown, the primary concentrated water line L3 is connected to a drain line for discharging a portion of the primary concentrated water to the outside during normal operation (production of water for injection) of the water for injection production apparatus 1. Similarly, although not shown, the water supply line L4 (specifically, downstream of the junction with the permeate lines L4a and L4b, described below) is connected to a return line for returning and circulating the water for injection obtained in the second UF membrane device 20 to the purified water tank 2 when there is no request to collect water from the water for injection tank. A purified water supply line L6 is also connected to the purified water tank 2, and purified water is supplied from a purified water production apparatus (not shown) as needed.

A pressure pump 3 is provided on the first water supply line L1, and a booster pump 4 is provided on the second water supply line L2. A heat exchanger 5 is also provided on the primary concentrate line L3. The pressure pump 3 pressurizes the purified water in the purified water tank 2 and supplies it to the first UF membrane device 10. The booster pump 4 boosts the pressure of the primary permeate from the first UF membrane device 10 and supplies it to the second UF membrane device 20. The heat exchanger 5 is used to generate hot water for heat sterilization during hot water sterilization, which is performed periodically between normal operations to reduce the number of viable bacteria in the system, and also to generate hot water for preheating during the steam sterilization process described below. Furthermore, the heat exchanger 5 may be used to heat the purified water or water for injection in the system so that the water can be drawn into the water for injection tank at a high temperature (e.g., 80°C or higher). Although not shown, temperature sensors are installed near the inlet and outlet of the heat exchanger 5 to confirm that the temperature within the system has risen to the specified temperature in the above-mentioned cases.

The first feedwater line L1 is connected to a bypass line L7 that branches off from the first feedwater line L1 downstream of the booster pump 3 and merges with the primary concentrated water line L3 upstream of the heat exchanger 5. The bypass line L7 is provided with an on-off valve V1 that is closed during normal operation and opened, for example, when hot water is produced by the heat exchanger 5. The secondary concentrated water line L5 is connected to a reflux line L8 that branches off from the secondary concentrated water line L5 and merges with the second feedwater line L2 upstream of the booster pump 4. This allows a portion of the secondary concentrated water to be refluxed upstream of the booster pump 4 during normal operation, ensuring the minimum amount of concentrated water required for the second UF membrane device 20 (the minimum flow rate of secondary concentrated water to be flowed through the secondary concentrated water line L5) even when the flow rate of the primary permeate from the first UF membrane device 10 is insufficient. Furthermore, if the flow rate of the primary permeate from the first UF membrane device 10 is sufficient to ensure such a minimum amount of concentrated water, the booster pump 4 and reflux line L8 do not necessarily need to be provided.

Furthermore, the first water supply line L1, second water supply line L2, primary concentrated water line L3, secondary concentrated water line L5, and reflux line L8 are each provided with discharge lines L31 to L34 for discharging hot water, steam, and condensed water introduced into the system during the steam sterilization process described below.

Specifically, an on-off valve V2 is provided downstream of the connection with the bypass line L7 in the first water supply line L1, and a first discharge line L11 is connected downstream via an on-off valve V3. Two on-off valves V4 and V5 are provided adjacent to each other in the second water supply line L2 (specifically, upstream of the connection with the reflux line L8), and a second discharge line L12 is connected therebetween via an on-off valve V6. An on-off valve V7 is provided upstream of the connection with the bypass line L7 in the primary concentrated water line L3, and a third discharge line L13 is connected upstream via an on-off valve V8. An on-off valve V9 is provided in the secondary concentrated water line L5 (although it is shown separated in the figure) adjacent to the purified water tank 2, and a fourth discharge line L14 is connected upstream via an on-off valve V10. An on-off valve V11 is provided near the downstream end of the return line L8 (specifically, the connection point with the second water supply line L2), and a fifth discharge line L15 is connected upstream of this via an on-off valve V12.

The second discharge line L12 is equipped with a temperature sensor 6 and a micro-hole on-off valve CV1, and the fifth discharge line L15 is equipped with a temperature sensor 7 and a micro-hole on-off valve CV2. The micro-hole on-off valves CV1 and CV2 are on-off valves with micro-holes that allow only condensed water to pass through even when fully closed. Examples of such on-off valves include grooved diaphragm valves and perforated ball valves. Although not shown, the first, fourth, and fifth discharge lines L11, L14, and L15 are also equipped with temperature sensors and micro-hole on-off valves, respectively, similar to the second and third discharge lines L12 and L13.

The first UF membrane device 10 has multiple (three in the illustrated example) UF membrane modules 11-13 connected in parallel, and the second UF membrane device 20 also has multiple (three in the illustrated example) UF membrane modules 21-23 connected in parallel. Each UF membrane module 11-13, 21-23 is a hollow fiber membrane module in which numerous hollow fiber UF membranes (hereinafter also referred to as "hollow fiber membranes") are bundled and packed into a cylindrical housing. The filtration method is an internal pressure crossflow system in which water to be treated is supplied from the inside of the hollow fiber membrane parallel to the membrane surface, permeated water is extracted from the outside, and water that does not permeate the membrane is discharged as concentrated water. Each UF membrane module 11-13, 21-23 has a water to be treated inlet and a concentrated water outlet at both longitudinal ends, and is arranged vertically with the water to be treated inlet facing downward and the concentrated water outlet facing upward. Each UF membrane module 11-13, 21-23 has two permeate outlets, one at the top and one at the bottom, on its side. Arranging the UF membrane modules 11-13, 21-23 in this manner not only allows for efficient discharge of the hot water introduced during the steam sterilization process described below, but is also advantageous in that the water to be treated flows upward when operation is subsequently restarted, preventing air pockets from forming within the hollow fiber membranes. Note that the UF membrane modules 11-13, 21-23 are not limited to internal pressure hollow fiber membrane modules; they may also be external pressure modules, in which water to be treated is supplied from the outside of the hollow fiber membranes and permeate is extracted from the inside.

In the first UF membrane device 10, a first water supply line L1 and a primary concentrate line L3 are connected to the bottom inlet for treated water and the top outlet for concentrated water, respectively, of the UF membrane modules 11-13. An upper permeate line L2a is connected to the permeate outlet at the top of the side of each UF membrane module 11-13, and a lower permeate line L2b is connected to the permeate outlet at the bottom of the side. The two permeate lines L2a and L2b merge and connect to the second water supply line L2. A primary discharge line L31 is connected to the first water supply line L1 (specifically, its downstream end) via an on-off valve V31, and a secondary discharge line L32 is connected to the lower permeate line L2b via an on-off valve V32. Each discharge line L31 and L32 is provided to discharge hot water and steam introduced into the UF membrane modules 11-13 during the steam sterilization process described below. Additionally, downstream of the connection point of the lower permeate line L2b with the secondary discharge line L32, a flow control valve V33 is provided to adjust the flow balance of the permeate flowing through the two permeate lines L2a and L2b.

In the second UF membrane device 20, a second water supply line L2 and a secondary concentrate line L5 are connected to the bottom inlets for treated water and the top concentrate outlets of the UF membrane modules 21-23, respectively. An upper permeate line L4a is connected to the permeate outlets at the top of the sides of the UF membrane modules 21-23, and a lower permeate line L4b is connected to the permeate outlets at the bottom of the sides. The two permeate lines L4a and L4b merge and are connected to the water supply line L4. A primary discharge line L33 is connected to the second water supply line L2 (specifically, its downstream end) via an on-off valve V34, and a secondary discharge line L34 is connected to the lower permeate line L4b via an on-off valve V35. Each discharge line L33 and L34 is provided to discharge hot water, steam, and condensed water introduced into the UF membrane modules 21-23 during the steam sterilization process described below. Additionally, a flow control valve V36 is provided downstream of the connection point of the lower permeate line L4b with the secondary discharge line L4b to adjust the flow balance of the two permeate lines L4a and L4b.

During normal operation of the water for injection production apparatus 1, a water sampling process is performed in which purified water stored in the purified water tank 2 is sequentially processed by the UF membrane devices 10 and 20, and the resulting water for injection is supplied to the water for injection tank (not shown) via the water supply line L4. During this process, a portion of the primary concentrate from the first UF membrane device 10 is discharged to the outside via a drain line (not shown) to prevent impurities from concentrating within the system, and the remainder is returned to the purified water tank 2 via the primary concentrate line L3. However, if there is no request to sample water from the water for injection tank and circulation operation is performed in which all of the water for injection obtained by the second UF membrane device 20 is returned to the purified water tank 2, there is no risk of the above-mentioned concentration proceeding, and all of the primary concentrate may be returned to the purified water tank 2. Meanwhile, a portion of the secondary concentrate from the second UF membrane device 20 is returned upstream of the booster pump 4 via the reflux line L8, and the remainder is returned to the purified water tank 2 via the secondary concentrate line L5. As a result, as described above, the minimum amount of concentrated water required for the second UF membrane device 20 can be ensured, thereby reducing the number of UF membrane modules that make up the first UF membrane device 10.

In the water for injection manufacturing apparatus 1, which produces water for injection used in pharmaceutical manufacturing, etc., a sterilization process is periodically performed between the normal operations described above to sterilize the system, including the UF membrane devices 10 and 20, using steam at 121°C or higher to prevent the growth of bacteria and microorganisms. To this end, the water for injection manufacturing apparatus 1 has a steam introduction line (steam introduction means) L20 for introducing steam into the system. The steam introduction line L20 branches into two lines, connected to the primary concentrated water line L3 and the secondary concentrated water line L5 via on-off valves V21 and V22, respectively. This allows steam to be introduced in parallel to the first and second UF membrane devices 10 and 20, as will be described in detail below. Note that "introducing in parallel" here refers not only to completely simultaneous introduction but also to at least partial temporal overlap. The series of steps in this steam sterilization process are described in detail below.

(Preliminary heating process)
The pre-heating step is a step of raising the temperature in the system to a predetermined temperature, for example, 80 to 90°C, in preparation for steam sterilization of the system of the water for injection manufacturing apparatus 1, in order to prevent a sudden rise in temperature due to the introduction of high-temperature steam. However, if high-temperature water (for example, water at 80 to 90°C) is circulated in the system during normal operation, the pre-heating step can be omitted.

During the preliminary heating step, water is not drawn into the water for injection tank. Accordingly, the water for injection production apparatus 1 produces water for injection in the same manner as during normal operation, except that the primary concentrated water from the first UF membrane device 10 is not discharged to the outside. At the same time, a heat medium (e.g., steam) is supplied to the heat exchanger 5, heating the primary concentrated water returned to the purified water tank 2. The water circulating within the system of the water for injection production apparatus 1 is also heated and maintained at, for example, 80-90°C. In this way, the hot water circulates within the system, raising the temperature of the entire system to approximately the same temperature. At this time, the on-off valve V1 of the bypass line L7 is opened, and a portion of the hot water flowing through the first water supply line L1 is returned to the purified water tank 2. This allows the water in the purified water tank 2 to be efficiently heated, even when the purified water tank 2 has a relatively large capacity. If steam is used as the heat medium for heat exchanger 5, steam inlet line L6 may branch off and connect to heat exchanger 4, thereby supplying steam to heat exchanger 4 from steam inlet line L6.

Then, the on-off valve V2 on the first water supply line L1, the on-off valve V7 on the primary concentrated water line L3, and the on-off valve V9 on the secondary concentrated water line L5 are closed, and the booster pump 4 is stopped, allowing hot water to continuously circulate only between the purified water tank 2 and the bypass line L7, while halting the circulation of hot water elsewhere. The on-off valves V3, V6, V8, V10, V12, V31, V32, V34, and V35 on each discharge line L11-L15 and L31-L34 are then opened, and clean air is introduced, for example, through a clean air inlet line (not shown). This forces the hot water in the system, excluding the circulation path, out and discharged to the outside through each discharge line L11-L15 and L31-L34. In addition, the return line (not shown) connected to the water supply line L4 also has a discharge line similar to each of the discharge lines L11-L15 and L31-L34, and the hot water in the return line is also discharged to the outside through this discharge line.

(Steam sterilization process)
The steam sterilization process is a process of sterilizing the system of the injection water supply device 1 using steam, specifically, a process of introducing steam into the system through the primary concentrated water line L3 and the secondary concentrated water line L5 and maintaining it for a certain period of time.

When it is confirmed that hot water is no longer being discharged from each discharge line L11-L15, L31-L34, and the introduction of clean air through the clean air inlet line is stopped, the steam sterilization process begins. In the steam sterilization process, steam is first introduced into the first UF membrane device 10 and the second UF membrane device 20.

Specifically, the on-off valve V21 on the steam inlet line L20 is opened, and the on-off valve V3 on the first discharge line L11, the on-off valve V4 on the second feedwater line L2, and the on-off valve V8 on the third discharge line L13 are closed, thereby introducing steam into the first UF membrane device 10 through the primary concentrated water line L3. The introduced steam flows through the primary side of each UF membrane module 11-13, then is discharged from the feedwater line L1 to the outside via the primary discharge line L31, and also passes through the secondary side of each UF membrane module 11-13, before being discharged from the permeate lines L2a and L2b to the outside via the secondary discharge line L32. At the same time, the on-off valve V22 on the steam inlet line L20 is also opened, and accordingly, the on-off valve V5 on the second feedwater line L2, the on-off valve V10 on the fourth discharge line L14, the on-off valve V11 on the reflux line L8, and the on-off valve (not shown) on the water supply line L4 are closed, thereby introducing steam into the second UF membrane device 20 through the secondary concentrated water line L5. The introduced steam flows through the primary side of each UF membrane module 21-23, and is then discharged from the feedwater line L1 to the outside via the primary side discharge line L33. It also passes through the secondary side of each UF membrane module 21-23 and is discharged from the permeate lines L4a and L4b to the outside via the secondary side discharge line L34.

In this way, steam is introduced into the first UF membrane device 10 and the second UF membrane device 20. By doing this in parallel, the time it takes for steam to reach the UF membranes of each UF membrane device 10, 20 after the completion of the preliminary heating step is shortened. As a result, the temperature drop of the UF membranes after the completion of the preliminary heating step is suppressed, and ultimately, a rapid temperature increase of the UF membranes due to the subsequent introduction of steam is suppressed. Another method for introducing steam into the first UF membrane device 10 and the second UF membrane device 20 in parallel is to introduce steam vertically upward from the respective treated water inlets via the first water supply line L1 and the second water supply line L2. However, residual water is likely to remain near the treated water inlets. This residual water is difficult to push out from below with steam, resulting in repeated collisions with the steam, which can cause water hammer and damage to the UF membranes. For this reason, it is preferable that steam be introduced into the first UF membrane device 10 and the second UF membrane device 20 vertically downward from their respective concentrated water outlets through the primary concentrated water line L3 and secondary concentrated water line L5, as in this embodiment. Furthermore, introducing steam vertically downward from the concentrated water outlets is also advantageous in that it allows for the efficient discharge of condensed water that forms within the hollow fiber membranes of each UF membrane module 11-13, 21-23.

After that, when the UF membrane devices 10, 20 have been sufficiently heated to the desired sterilization temperature (e.g., 121°C or higher), the micro-hole on-off valves (not shown) on each discharge line L31-L34 of the UF membrane devices 10, 20 are closed. Whether the UF membrane devices 10, 20 have been sufficiently heated can be confirmed by checking whether the detection value of the temperature sensors (not shown) installed on each discharge line L31-L34 reaches or exceeds a predetermined value. In this way, the discharge of steam from each discharge line L31-L34 of the UF membrane devices 10, 20 is stopped, and once only condensed water is being discharged, the introduction of steam into the remaining system begins, gradually expanding the range of steam introduction.

Specifically, first, the on-off valve V4 of the second water supply line L2 is opened, causing steam introduced into the first UF membrane device 10 to be discharged from the second water supply line L2 to the outside via the second discharge line L12. This allows steam to be introduced into the portion of the second water supply line L2 from the first UF membrane device 10 to its connection with the second discharge line L12 (hereinafter also referred to as the "upstream portion"). Then, when it is confirmed that the detection value of the temperature sensor 6 has reached or exceeded a predetermined value, i.e., that the upstream portion of the second water supply line L2 has been sufficiently heated, the on-off valve V4 of the second water supply line L2 is closed, and the flow of steam from the upstream portion of the second water supply line L2 to the second discharge line L12 is stopped. At the same time, the on-off valve V5 of the second water supply line L2 is opened, causing the steam introduced into the second UF membrane device 20 to be discharged from the second water supply line L2 to the outside via the second discharge line L12. This introduces steam into the section of the second water supply line L2 from its connection with the second discharge line L12 to the second UF membrane device 20 (hereinafter also referred to as the "downstream section"). Then, when it is confirmed that the detection value of the temperature sensor 6 has reached a predetermined value or higher, i.e., that the downstream section of the second water supply line L2 has been sufficiently heated, the micro-hole on-off valve CV1 of the second discharge line L12 is closed so that only condensed water is discharged from the second discharge line L12. In this way, steam is introduced into the second water supply line L2 within the system of the water for injection manufacturing apparatus 1.

Even if the second supply water line L2 does not have on-off valves V4 and V5, it is conceivable that steam can also be introduced into the second supply water line L2 when steam is introduced into the first UF membrane device 10 and the second UF membrane device 20, as long as the second discharge line L12 is connected. However, when steam is introduced into the first and second UF membrane devices 10 and 20, the steam flowing in from the first UF membrane device 10 and the steam flowing in from the second UF membrane device 20 collide in the second supply water line L2 connecting the two, easily forming air pockets. As a result, steam may not flow sufficiently through the second discharge line L12, or steam may be more likely to flow in from only one of the first UF membrane device 10 or the second UF membrane device 20, which may result in insufficient temperature rise in the second supply water line L2. Therefore, in order to prevent the above-mentioned collision of steam, it is preferable that the second feedwater line L2 be provided with on-off valves V4 and V5 as shutoff means for shutting off the flow of steam when steam is introduced into the first and second UF membrane devices 10 and 20.

Steam can be introduced into the second water supply line L2 from either the upstream or downstream portion, or both simultaneously. However, if the on-off valves V4 and V5 of the second water supply line L2 are opened simultaneously, as described above, steam may flow only through either the upstream or downstream portion. Even if the detection value of the temperature sensor 6 reaches a predetermined value, it is not possible to determine whether the upstream or downstream portion has been sufficiently heated. Therefore, it is preferable to introduce steam into the second water supply line L2 separately from the upstream and downstream portions by switching the on-off valves V4 and V5 between open and closed, as in this embodiment.

Next, the on-off valve V12 of the fifth discharge line L15 is opened, causing the steam that has flowed into the secondary concentrated water line L5 to be discharged from the reflux line L8 through the fifth discharge line L15 to the outside, thereby introducing steam into the reflux line L8. Then, when it is confirmed that the detection value of the temperature sensor 7 has reached a predetermined value or higher, i.e., that the reflux line L8 has been sufficiently heated, the micro-hole on-off valve CV2 of the fifth discharge line L15 is closed so that only condensed water is discharged from the fifth discharge line L15. Similar to the second feedwater line L2, the reflux line L8 can also be considered a connecting line connecting the first UF membrane device 10 and the second UF membrane device 20. Therefore, as with the second feedwater line L2, if the reflux line L8 is not provided with an on-off valve V11, when steam is introduced into the first and second UF membrane devices 10, 20, there is a risk of air pockets being formed due to collision between steam flowing in from the primary concentrated water line L3 of the first UF membrane device 10 and steam flowing in from the second UF membrane device 20 through the second feedwater line L2. However, like the on-off valves V4, V5 of the second feedwater line L2, the on-off valve V11 functions as a shutoff means for shutting off the flow of steam in the reflux line L8, thereby preventing the formation of such air pockets.

Then, the on-off valve V3 of the first discharge line L11, the on-off valve V8 of the third discharge line L13, and the on-off valve V10 of the fourth discharge line L14 are opened in sequence as shown below, thereby sequentially introducing pure water into the system of the water for injection manufacturing apparatus 1. However, the order in which the on-off valves V8, V10, and V12 are opened is not limited to the following.

That is, first, the on-off valve V3 of the first discharge line L11 is opened, and steam is introduced into the portion of the first feedwater line L1 from the first UF membrane device 10 to its connection with the first discharge line L11. Then, when it is determined that the temperature of that portion has risen sufficiently based on the detection results of a temperature sensor (not shown) installed in the first discharge line L11, the on-off valve with micro-holes (not shown) installed in the first discharge line L11 is closed so that only condensed water is discharged from the first discharge line L11. At the same time, the on-off valve V8 of the third discharge line L13 is opened, and steam is introduced into the portion of the primary concentrated water line L3 downstream of its connection with the steam inlet line L20. Then, when it is determined that the temperature of that portion has risen sufficiently based on the detection results of the temperature sensor (not shown) installed in the third discharge line L13, the on-off valve with micro-holes (not shown) installed in the third discharge line L13 is closed so that only condensed water is discharged from the third discharge line L13. At the same time, the on-off valve V10 of the fourth discharge line L14 is opened, and steam is introduced into the portion of the secondary concentrated water line L5 downstream of its connection with the steam inlet line L20. When a temperature sensor (not shown) installed in the fourth discharge line L14 detects that the temperature of that portion has risen sufficiently, the on-off valve (not shown) with microholes installed in the fourth discharge line L14 is closed so that only condensed water is discharged from the fourth discharge line L14. While not described in detail, steam is also introduced into the return line (not shown) connected to the water supply line L4 in the same manner as described above.

Steam is introduced into the system in this way, and this state is maintained for a certain period of time, thereby sterilizing the water for injection manufacturing device 1.

(Temperature cooling process)
The temperature-lowering step is a step of lowering the temperature in the system to a temperature at which water can be collected into the water for injection tank when normal operation of the water for injection manufacturing apparatus 1 is resumed after the steam sterilization step is completed.

After the steam introduction has been performed for a certain period of time, the on-off valves V21 and V22 on the steam introduction line L20 are closed, halting the introduction of steam. Thus, the steam sterilization process is completed. For example, when the temperature within the system drops to 105°C or below, the temperature-reducing process begins. In the temperature-reducing process, the on-off valves V3, V6, V8, V10, V12, V31, V32, V34, and V35 on each discharge line L11-L15 and L31-L34 are closed, and the on-off valve V2 on the first water supply line L1, the on-off valve V7 on the primary concentrated water line L3, and the on-off valve V9 on the secondary concentrated water line L5 are opened. Then, the booster pump 4 is activated, and the hot water that circulated between the purified water tank 2 and the bypass line L7 during the steam sterilization process flows through the system via the first water supply line L1, resulting in the same hot water circulation as during the preliminary heating process. Thereafter, the amount of heat medium supplied to the heat exchanger 5 is gradually reduced, or a portion of the circulating hot water is discharged to the outside, and accordingly, room temperature purified water is gradually supplied to the purified water tank 2 through the purified water supply line L6, thereby starting to cool the hot water. When the circulating hot water has cooled to about room temperature, normal operation of the water for injection manufacturing apparatus 1 resumes, and in response to a request to collect water from the water for injection tank, water for injection manufactured by the water for injection manufacturing apparatus 1 is supplied to the water for injection tank through the water supply line L4. Note that if high-temperature water is circulated within the system during normal operation, cooling of the hot water can be omitted.

Figures 3(a) and 3(b) are schematic diagrams showing modified examples of the apparatus for producing water for injection according to this embodiment, and correspond to Figure 2.

The connection position of the second discharge line L12 to the second water supply line L2 is not limited to a position distant from the first and second UF membrane devices 10 and 20; for example, it may be a position close to the first UF membrane device 10. That is, as shown in FIG. 3(a), an on-off valve V4 may be provided close to the upstream end of the second water supply line L2 (specifically, the confluence with the permeate lines L2a and L2b), and the second discharge line L12 may be connected near its downstream side. In this case, the remaining on-off valve V5 provided in the above-described configuration may not be provided on the second water supply line L2. Alternatively, although not shown, the second discharge line L12 may be connected to the second water supply line L2 at a position close to the second UF membrane device 20. For example, an on-off valve V5 may be provided on the second water supply line L2 upstream of and close to the junction with the return line L8, and a second drain line L12 may be connected upstream of the on-off valve V5. In this case, the remaining on-off valve V4 provided in the above-described configuration may not be provided on the second water supply line L2. The number of second drain lines L12 does not have to be one. For example, as shown in FIG. 3(b), two second drain lines L12a and L12b may be connected to the second water supply line L2 close to each other. In this case, too, only one on-off valve V4 of the two on-off valves V4 and V5 provided in the above-described configuration may be provided on the second water supply line L2 between their connections, and the remaining on-off valve V5 may not be provided.

These modified examples are advantageous in that, as long as the on-off valve V4 (or on-off valve V5) is closed when steam is introduced into the first and second UF membrane devices 10, 20, steam can also be introduced into the second feedwater line L2 without any other operation being required. In the modified example shown in Figure 3(a), it is preferable to conduct a trial run in advance to confirm that the portion of the second feedwater line L2 upstream of the on-off valve V4 is sufficiently heated by the steam introduced into the first UF membrane device 10, even when the on-off valve V4 is closed.

Although not shown, as in the case of the second discharge line L12 described above, the connection position and number of the fifth discharge line L15 to the reflux line L8 may be changed. That is, an on-off valve V11 may be provided near the upstream end of the reflux line L5 (specifically, the branch point with the secondary concentrated water line L5), and the fifth drain line L15 may be connected near its downstream side. Alternatively, the on-off valve V11 and another on-off valve may be provided close to each other at positions away from the upstream and downstream ends of the reflux line L8, and the fifth drain line L15 may be connected between them. Furthermore, two fifth drain lines L15 may be connected close to each other at positions away from the upstream and downstream ends of the reflux line L8, with the on-off valve V11 sandwiched between them.

Second Embodiment
4 is a schematic diagram of an apparatus for preparing water for injection according to a second embodiment of the present invention. This embodiment differs from the first embodiment in that the purified water tank is also steam sterilized. The following description will focus on this difference.

In this embodiment, the steam introduction line L20 is connected to the purified water tank 2 via an on-off valve V23. Accordingly, a sixth discharge line L16 is provided on the first water supply line L1 upstream of the pressure pump 3 via an on-off valve V13. Like the other discharge lines L11 to L15, the sixth discharge line L16 is provided to discharge hot water from the purified water tank 2 to the outside during the preliminary heating process and to discharge steam introduced into the purified water tank 2 to the outside during the steam sterilization process. Although not shown, the sixth discharge line L16 is also provided with a temperature sensor and an on-off valve with a micro-hole, just like the other discharge lines L11 to L15.

Due to these changes in configuration, the steam sterilization process steps in this embodiment differ from those in the first embodiment in the following ways:

That is, during the preliminary heating process, when the temperature within the system rises to a predetermined temperature due to the circulation of hot water, the on-off valve V2 on the first water supply line L1, the on-off valve V7 on the primary concentrated water line L3, and the on-off valve V9 on the secondary concentrated water line L5 remain open, and the booster pump 4 and the pressure pump 3 are stopped. This stops all circulation of hot water within the system. Then, the on-off valve V13 on the sixth discharge line L16 is opened, and when the hot water within the system is discharged to the outside, the hot water in the purified water tank 2 is similarly discharged to the outside via the sixth discharge line L16.

During the steam sterilization process, the on-off valve V23 of the steam inlet line L20 is opened, and the on-off valve V2 of the first feedwater line L1, the on-off valve V7 of the primary concentrated water line L3, and the on-off valve V9 of the secondary concentrated water line L5 are closed, thereby introducing steam into the purified water tank 2. When the temperature of the purified water tank 2 is confirmed to be sufficiently elevated based on the detection results of a temperature sensor (not shown) installed in the sixth discharge line L11, the micro-hole on-off valve (not shown) installed in the sixth discharge line L16 is closed so that only condensed water is discharged from the sixth discharge line L16. The on-off valve V7 of the primary concentrated water line L3 and the on-off valve V9 of the secondary concentrated water line L5 are then opened, thereby introducing steam in parallel from the purified water tank 2 through the primary concentrated water line L3 and the secondary concentrated water line L5 to the first UF membrane device 10 and the second UF membrane device 20. This allows the purified water tank 2 to be sterilized while simultaneously heating the UF membrane devices 10 and 20.

During the temperature-lowering process, the on-off valve V23 on the steam inlet line L20 is closed to stop the introduction of steam. The system of the water for injection production apparatus 1 is first cooled by clean air introduced from the clean air inlet line (not shown) through the purified water tank 2. Thereafter, for example, when the temperature of the purified water tank 2 drops below 90°C, the introduction of clean air is stopped. Then, the supply of purified water to the purified water tank 2 begins via the purified water supply line L6, and normal operation of the water for injection production apparatus 1 resumes. Specifically, the on-off valves V3, V6, V8, V10, V12, V13, V31, V32, V34, and V35 on each discharge line L11-L16 and L31-L34 are closed, and the pressure pump 3 and booster pump 4 are activated. This resumes normal operation, in which the purified water in the purified water tank 2 is sequentially treated in the UF membrane devices 10 and 20. When replenishing purified water into the purified water tank 2, it is preferable to start with preheated purified water and then gradually lower its temperature to prevent large temperature changes within the system.

(Third embodiment)
5 is a schematic diagram of an apparatus for producing water for injection according to a third embodiment of the present invention. This embodiment differs from the first embodiment in that a first UF membrane device and a second UF membrane device are connected in parallel. The following description will focus on this difference.

In this embodiment, the first UF membrane device 10 and the second UF membrane device 20 are connected in parallel between the first water supply line L1 and the water supply line L4. Specifically, the first water supply line L1 is connected to the treated water inlets of the first and second UF membrane devices 10, 20 via two branch water supply lines L21, L22, and the water supply line L4 is connected to the permeate outlets of the first and second UF membrane devices 10, 20 via two branch water supply lines L23, L24. In other words, in this embodiment, two branch water supply lines L21, L22 are provided that branch purified water flowing through the first water supply line L1 and supply it to the first and second UF membrane devices 10, 20, and two branch water supply lines L23, L24 are provided that allow permeate water from the first and second UF membrane devices 10, 20 to flow through and merge with the water supply line L4.

Accordingly, in this embodiment, the second water supply line L2 is omitted, and the on-off valves V4 and V5 and the second discharge line L12 that were provided in the second water supply line L2 are provided in the second branch water supply line L22, which is a connecting line connecting the first UF membrane device 10 and the second UF membrane device 20, just like the second water supply line L2. The booster pump 4 that was provided in the second water supply line L2 is also omitted, and therefore the fifth discharge line L15 is also not provided. In this embodiment, two on-off valves V14 and V15 are provided close to each other in the second branch water supply line L24, which is a connecting line connecting the first UF membrane device 10 and the second UF membrane device 20, and a seventh discharge line L17 is connected between them via an on-off valve V16. The seventh discharge line L17 is provided with a temperature sensor 8 and a micro-hole on-off valve CV3, similar to the second discharge line L12. The on-off valves V4 and V5 and the second discharge line L12 may be provided in the first branch water supply line L21 instead of the second branch water supply line L22, and the on-off valves V14 and V15 and the seventh discharge line L17 may be provided in the first branch water supply line L23 instead of the second branch water supply line L24.

The steam sterilization process in this embodiment is similar to that in the first embodiment, except that during the steam sterilization process, after steam is introduced into the first and second UF membrane devices 10, 20, steam is introduced into the second branch water supply line L22 in the same manner as for the second water supply line L2, and steam is introduced into the second branch water supply line L24. As with the second water supply line L2, steam is introduced into the second branch water supply line L24 by switching the on-off valves V14, V15 between on and off, based on the detection results of the temperature sensor 8 installed in the seventh discharge line L17. Also, similar to the first embodiment, once it is confirmed that the temperature of the second branch water supply line L24 has been sufficiently increased, the micro-hole on-off valve CV3 in the seventh discharge line L17 is closed so that only condensed water is discharged from the seventh discharge line L17.

In this embodiment, as in the modified example of the first embodiment (Figure 3), the connection position and number of the second discharge line L12 to the second branch water supply line L22 may be changed. That is, an on-off valve V4 may be provided near the upstream end of the second branch water supply line L22 (specifically, the branch point with the first branch water supply line L21), and the second drain line L12 may be connected near the downstream side thereof. In this case, an on-off valve V5 may not be provided in the second branch water supply line L22. Alternatively, an on-off valve V5 may be provided near the downstream end of the second branch water supply line L22 (specifically, the connection point with the first UF membrane module 21 of the second UF membrane device 20), and the second drain line L12 may be connected near the upstream side thereof. In this case, an on-off valve V4 may not be provided in the second branch water supply line L22. Additionally, two second discharge lines L12 may be connected to the second branch water supply line L22 in close proximity to each other. In this case, too, only the on-off valve V4 may be provided between the connections, and the on-off valve V5 may not be provided.

The connection position and number of the seventh discharge line L17 to the second branch water supply line L24 may also be changed in a similar manner. That is, an on-off valve V14 may be provided near the upstream end of the second branch water supply line L24 (specifically, the connection point with the third UF membrane module 23 of the second UF membrane device 20), with the seventh drainage line L17 connected near its downstream side. In this case, the on-off valve V15 may not be provided in the second branch water supply line L24. Alternatively, the on-off valve V15 may be provided near the downstream end of the second branch water supply line L24 (specifically, the confluence point with the first branch water supply line L23), with the seventh drainage line L17 connected near its upstream side. In this case, the on-off valve V14 may not be provided in the second branch water supply line L24. Additionally, two seventh discharge lines L17 may be connected to the second branch water supply line L22 in close proximity to each other. In this case, too, only the on-off valve V14 may be provided between the connections, and the on-off valve V15 may not be provided.

In the above-described embodiment, an example was given in which multiple UF membrane devices were connected in series or parallel, but the connection configuration of multiple UF membrane devices is not limited to this and may be a combination of series and parallel.

1. Water for injection production equipment (water treatment equipment)
4 Booster pump 6, 7 Temperature sensor 10 First UF membrane device 20 Second UF membrane device 11-13, 21-23 UF membrane module L2 Second water supply line (supply line)
L3 Primary concentrated water line L5 Secondary concentrated water line L8 Reflux line L12 Second discharge line L17 Seventh discharge line L20 Steam introduction line (steam introduction means)
L21, L22 Branch water supply line L23, L24 Branch water transmission line V4, V5, V11, V14, V15 Opening and closing valve (shutoff means)

Claims (9)

a plurality of ultrafiltration membrane devices each having at least one ultrafiltration membrane module;
a steam introducing means for introducing steam into the plurality of ultrafiltration membrane devices in parallel;
a shutoff means provided in a connection line connecting a first ultrafiltration membrane device and a second ultrafiltration membrane device among the plurality of ultrafiltration membrane devices, and configured to shut off the flow of steam in the connection line;
At least one exhaust line connected to the connection line and configured to exhaust the blocked steam to the outside;
and at least one temperature sensor disposed in the at least one discharge line . a plurality of concentrated water lines through which concentrated water discharged from the plurality of ultrafiltration membrane devices flows;
The water treatment device according to claim 1 , wherein the steam introducing means is capable of introducing steam into each of the plurality of ultrafiltration membrane devices through the plurality of concentrated water lines. the at least one ultrafiltration membrane module is an internal pressure cross-flow type hollow fiber membrane module, and is arranged so that a concentrated water outlet of the hollow fiber membrane module faces upward;
The water treatment device according to claim 2 , wherein the plurality of concentrate lines are connected to the concentrate outlet of the at least one ultrafiltration membrane module of the plurality of ultrafiltration membrane devices, respectively. a supply line through which permeated water from the first ultrafiltration membrane device flows and supplies the permeated water to the second ultrafiltration membrane device;
The water treatment device according to claim 1 , wherein the connection line is the supply line. a booster pump provided in the supply line;
The water treatment device according to claim 4 , further comprising: a reflux line branching off from the concentrated water line of the second ultrafiltration membrane device and connected to the supply line upstream of the booster pump. a supply line through which permeated water from the first ultrafiltration membrane device flows and supplies the permeated water to the second ultrafiltration membrane device;
a booster pump provided in the supply line;
a reflux line branching from the concentrated water line of the second ultrafiltration membrane device and connected to the supply line upstream of the booster pump;
The water treatment device according to claim 1 , wherein the connection line is the return line. two branch water supply lines that branch and supply the water to be treated to the first ultrafiltration membrane device and the second ultrafiltration membrane device;
The water treatment device according to claim 1 , wherein the connection line is one of the two branch water supply lines. two branch water supply lines through which the permeated water from the first ultrafiltration membrane device and the permeated water from the second ultrafiltration membrane device are circulated and joined together;
The water treatment device according to claim 1 , wherein the connection line is one of the two branch water supply lines. 1. A method for operating a water treatment system having a plurality of ultrafiltration membrane devices, each having at least one ultrafiltration membrane module, comprising:
introducing steam into the plurality of ultrafiltration membrane devices in parallel and sterilizing the plurality of ultrafiltration membrane devices with the steam ;
When introducing steam into the plurality of ultrafiltration membrane devices, the method includes introducing steam into a connection line connecting a first ultrafiltration membrane device and a second ultrafiltration membrane device among the plurality of ultrafiltration membrane devices, and sterilizing the connection line with the steam ,
The step of introducing steam into the connection line includes switching between blocking the flow of steam from the second ultrafiltration membrane device to the connection line by a blocking means provided on the connection line, while circulating steam from the first ultrafiltration membrane device to the connection line and discharging the steam to the outside through at least one discharge line connected to the connection line, and blocking the flow of steam from the first ultrafiltration membrane device to the connection line, while circulating steam from the second ultrafiltration membrane device to the connection line and discharging the steam to the outside through at least one discharge line, based on the detection value of at least one temperature sensor provided on the at least one discharge line .