JP3558251B2 - Filtration tower and method of operating the same - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a filtration tower which is preferably used when removing suspended substances from high-temperature water having a water temperature of 100 ° C. or higher, which changes into steam under atmospheric pressure, such as heater drain water in a power plant, and its operation. About the method.
[0002]
Problems to be solved by the prior art and the invention
For example, since the heater drain water of a pressurized water nuclear power plant or a thermal power plant is high temperature water of at least 100 ° C., this high temperature water is mainly recovered to a condensing system and repeatedly used as steam generation water, and the heat of the condensing system is We try to prevent loss as much as possible. Such high-temperature water contains suspended substances such as iron oxide fine particles during repeated use, but at present, there is no filtration tower suitable for high-temperature water filtration, so high-temperature water must be treated at all. Is supplied to the steam generator or boiler. However, if suspended materials such as iron oxide fine particles contained in high-temperature water are repeatedly used as water for steam generation without treatment, these suspended materials adhere to the outer surface of the steam generator or the heat transfer tube of the boiler, and the respective suspended materials adhere to each other. There were problems such as lowering the heat transfer efficiency.
[0003]
Therefore, conventionally, a filter using an inorganic filter such as a metal filter or a ceramic filter has been studied as a filtration tower for high-temperature water. Since these inorganic filters have heat resistance, they can be used for high-temperature water such as heater drain water, but the iron component such as iron oxide, which is the main component of the suspended substance, is extremely fine particles. However, there is a problem that the iron removal performance is unstable, the differential pressure easily rises, or impurities are easily eluted from the filter itself, so that it has not yet been fully introduced.
[0004]
The present invention has been made to solve the above problems, and has as its object to provide a filtration tower capable of removing suspended substances in high-temperature water such as, for example, heater drain water. Further, the present invention, for example, when filtering high-temperature water such as heater drain water, it is possible to smoothly pass water without impairing the filtration function of the polymer membrane filter element, and to efficiently remove suspended substances in the high-temperature water. It is an object of the present invention to provide a filter tower and a method of operating the same.
[0005]
[Means for Solving the Problems]
The present inventors have found that the polymer membrane filter is capable of reducing the pore size, has a stable performance of removing suspended substances such as iron oxide fine particles, and has no elution of impurities from the membrane itself. Focusing on having such characteristics, various studies were made on the structure of a filtration tower equipped with a polymer membrane filter for use in high-temperature water. For example, in the case of filtering high-temperature water such as heater drain water using a filtration tower, when starting filtration, water having a water temperature (10 to 30 ° C.) substantially equal to the ambient temperature that is full in the tower body 51 is used. Although filtration is performed while replacing with high-temperature water, in the case of a conventional polymer membrane filter, the polymer membrane filter is thermally degraded by high-temperature water and cannot maintain its original filtration performance. Accordingly, the present inventors have made various changes in the polymer material of the polymer membrane filter and have examined variously the processability and the filtration performance. As a result, the specific heat-resistant polymer material is a polymer membrane filter for high-temperature water. It was found that it can be used as.
[0006]
Furthermore, as a result of further study on the filtration performance of the filtration tower shown in FIG. 4 equipped with a specific polymer membrane filter, special contrivance was applied to the structure of the filtration tower, and by adopting a specific operation mode, the heater drain water and the like were removed. It has been found that even in such high-temperature water, suspended substances such as iron oxide fine particles can be efficiently and stably removed.
[0007]
The present invention has been made based on the above findings, and the filtration tower according to claim 1 has a partition plate for partitioning the inside of the tower body into a lower chamber and an upper chamber, and an end is fixed to the partition plate and A plurality of polymer membrane filter elements disposed in the lower chamber along the axis of the tower body, By inflow pipe The raw water flowing into the lower chamber is filtered by the respective polymer membrane filter elements, and the filtered water collected in the upper chamber is filtered. From the outflow pipe In the filtration tower to be discharged, Only the lower chamber and the upper chamber were connected by a communication pipe, and a gate valve was provided in this communication pipe. It is characterized by the following.
[0009]
In addition, the present invention Claim 2 The operation method of the filtration tower described in the above, is a partition plate for partitioning the inside of the tower body into a lower chamber and an upper chamber, an end fixed to the partition plate, and disposed in the lower chamber along the axis of the tower body. A plurality of polymer membrane filter elements provided, a communication pipe connecting the lower chamber and the upper chamber, and a method of operating a filtration tower including a gate valve provided in the communication pipe, Prior to starting filtration of raw water using a filtration tower, after opening the gate valve and communicating the lower chamber and the upper chamber by the communication pipe, the raw water is sequentially passed through the lower chamber and the communication pipe. The air is supplied to the upper chamber through the lower chamber and the pressure in the lower chamber and the pressure in the upper chamber are equalized.
[0010]
In addition, the present invention Claim 3 The operation method of the filtration tower described in Claim 2 In the invention described in (1), high-temperature water of 100 ° C. or more is used as the raw water.
[0011]
In addition, the present invention Claim 4 The operation method of the filtration tower described in Claim 2 Or Claim 3 In the invention described in (1), the gate valve is gradually closed from a fully open state to a fully closed state.
[0012]
In addition, the present invention Claim 5 The operation method of the filtration tower described in Claim 4 In the invention described in the above, the valve operation time for gradually closing the gate valve from the fully open state to the fully closed state is longer than at least the time required for replacing the water retained in the tower body with the raw water. It is characterized by the following.
[0013]
In addition, the present invention Claim 6 The operation method of the filtration tower described in Claim 2 ~ Claim 5 In the invention according to any one of the above, prior to stopping the filtration of the raw water, a gate valve of the communication pipe is opened.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, the present invention will be described based on the embodiment shown in FIGS. In each of the drawings, FIG. 1 is a flowchart showing a power plant to which the filtration tower of the present invention is applied, and FIG. 2 is a configuration showing one embodiment of the filtration tower of the present invention applied to the power plant shown in FIG. FIG. 3 is a sectional view showing a hollow fiber membrane module used as a polymer membrane filter element of the filtration tower shown in FIG. 2, and FIG. Filtration tower that can be suitably used for the operation method FIG. In FIG. 1, the solid line is a water piping line, and the broken line is a steam piping line.
[0015]
First, a power plant to which the filtration tower of the present embodiment is applied will be outlined with reference to FIG. The power plant is a system that generates power by rotating a turbine using high-temperature and high-pressure steam as shown in FIG. That is, when high-temperature and high-pressure steam is generated in the steam generator 1, the high-temperature and high-pressure steam is supplied to the high-pressure turbine 2, and drives a generator via the high-pressure turbine 2. The steam whose energy has been consumed in the high-pressure turbine 2 is mainly subjected to moisture separation in the moisture separator 3. The steam from which the water has been separated is reheated in the reheater 4 using a part of the steam generated in the steam generator 1. The reheated steam is supplied to the low-pressure turbine 5 and drives a generator via the low-pressure turbine 5. The steam whose energy has been consumed in the low-pressure turbine 5 is mainly supplied to the condenser 6 and is cooled in the condenser 6 to be condensed. This condensate is supplied to the condensate demineralizer 8 by the pump 7, and impurity ions such as metal ions mixed in the condensate are removed in the condensate demineralizer 8. Although not shown, a filtration tower may be provided in front of the condensate desalination apparatus 8, and in such a case, suspended substances such as iron oxide fine particles are removed in the filtration tower. .
[0016]
The condensate from which the impurity ions have been removed in the condensate desalination device 8 is supplied to a low-pressure heater 10 by a pump 9. The low-pressure heater 10 receives a part of the steam from the low-pressure turbine 5 and heats the condensate supplied from the condensate desalination device 8. Then, the heater drain water generated in the low-pressure heater 10 merges with the condensate heated by the low-pressure heater 10 and is supplied to the deaerator 11. The condensate from which oxygen and the like dissolved in the condensate have been deaerated in the deaerator 11 is supplied to a high-pressure heater 13 by a pump 12. The high-pressure heater 13 receives a part of the steam from the high-pressure turbine 2 and heats the condensate received from the deaerator 11, and the condensate having a high temperature is supplied to the steam generator 1 again and used for circulation. . In addition, the deaerator 11 receives the heater drain water of the reheater 4 and the high-pressure heater 13 and the drain water generated in the moisture separator 3 in addition to the condensate from the condensate desalination device 8 and uses them for generating steam. It is like that.
[0017]
Now, of the condensate supplied to the deaerator 11, the moisture separator drain water separated in the moisture separator 3 and the heater drain water of the high-pressure heater 13 all flow out of the high-pressure turbine 2, Since each water contains suspended substances such as iron oxide fine particles, it is not preferable to supply the water to the steam generator 1 as it is, and the suspended substances in each drain water are removed in advance using a filtration tower. Need to be kept. Since all of these drain waters are high-temperature waters of 100 ° C. or more, in the present embodiment, the water separator shown in FIG. The filtration tower 20 of the embodiment was used. The filtration tower 20 disposed in the pipe 14 filters drain water from the moisture separator 3 (hereinafter, referred to as “moisture separator drain water”), and the filtration tower 20 disposed in the pipe 15 is a high-pressure heater. Drain water (hereinafter, referred to as “high-pressure heater drain water”) from the filter 13, which has basically the same configuration. Each of these drain waters reaches 100 ° C. or higher, and usually reaches 150 ° C. or higher and 200 ° C. or higher. Therefore, the filtration tower 20 of the present embodiment is preferably used under high-temperature water of 100 ° C. or higher, and is also preferably used under the above-mentioned drain water of 150 ° C. or higher, and more preferably 200 ° C. or higher.
[0018]
Therefore, the filtration tower 20 for high-pressure heater drain water will be described as an example. As shown in FIG. 2, the filtration tower 20 has a tower body 21, a partition plate 24 for dividing the inside of the tower body 21 into a lower chamber 22 and an upper chamber 23, and an upper end fixed to the partition plate 24 and a lower end. And a plurality of polymer membrane filter elements 25 hanging down to the lower chamber 22 side. High-pressure heater drain water is guided into the lower chamber 22 through the pipe 15 and the inflow pipe 26, and the polymer membrane filter in the lower chamber 22 is provided. After being filtered by the element 25 and removing suspended substances such as iron oxide fine particles from the high-pressure heater drain water, the filtered water is supplied to the deaerator 11 through the outflow pipe 27 and the pipe 15.
[0019]
A baffle plate 28 is disposed at the center near the bottom in the lower chamber 22 so as to face the inlet of the high-pressure heater drain water, and the baffle plate 28 disperses the heater drain water flowing into the lower chamber 22. is there. A distribution mechanism 29 is provided between the baffle plate 28 and the lower end of the hollow fiber membrane module 25. The distribution mechanism 29 temporarily receives the high-pressure heater drain water from the baffle plate 28, and continuously receives the hollow fiber membrane module 25. The high-pressure heater drain water is distributed to the heater.
[0020]
Further, the filtration tower 20 of the present embodiment is provided with a communication pipe 30 that communicates the upper end of the lower chamber 22 with the upper chamber 23, and a gate valve 31 is provided in the communication pipe 30. By opening and closing the gate valve 31, the lower chamber 22 and the upper chamber 23 are communicated or shut off. This communication pipe 30 is used when the operation method of the present invention is performed at the start of filtration. Once the filtration tower 20 enters a steady operation, the gate valve 31 is closed so that the communication pipe 30 is not used. Further, by connecting one end of the communication pipe 30 to the upper end of the lower chamber 22, the water retained in the lower chamber 22 can be reliably pushed out to the upper chamber 23 in preference to the high-temperature water.
[0021]
As the polymer membrane filter element 25, for example, a hollow fiber membrane type, pleated type, or spiral type polymer membrane filter can be used. Thus, in the present embodiment, a case will be described in which, for example, a hollow fiber membrane module is used as the polymer membrane filter element 25. Accordingly, hereinafter, the polymer membrane filter element 25 will be described as the hollow fiber membrane module 25 shown in FIG. In FIG. 2, 15A is a bypass pipe of the pipe 15, and 15B is a valve of the bypass pipe 15A.
[0022]
Next, the hollow fiber membrane module 25 will be described with reference to FIG. As shown in the figure, the hollow fiber membrane module 25 includes about 100 to 50,000 hollow fiber membrane filters 251 and a protection cylinder 252 that bundles and stores the hollow fiber membrane filters 251. I have. Each hollow fiber membrane filter 251 is formed as a hollow fiber having an outer diameter of 0.3 to 5 mm and an inner diameter of 0.2 to 4 mm by a resin thin film having fine pores of, for example, 0.01 to 0.3 μm. A flange 252A is formed at the upper end of the protective cylinder 252, and the flange 252A hangs down from the partition plate 24.
[0023]
Further, a skirt portion 252B is formed at a lower end portion of the protective cylinder 252, and the skirt portion 252B collects gas flowing in at the time of cleaning. An upper joint 253 is formed by binding the upper end of each hollow fiber membrane filter 251 with an adhesive or the like at the upper end of the protective cylinder 252 and joining the lower end thereof to the lower end of each hollow fiber membrane filter 251. A lower joining portion 254 joined and fixed similarly to the upper end portion is formed. At the upper joint 253, each hollow fiber membrane filter 251 is open, and at the lower joint 254, each hollow fiber membrane filter 251 is closed, and filtered water flows out of the opening of the hollow fiber membrane filter 251 and collects in the upper chamber 23. It is watered. When collecting water from both ends of each hollow fiber membrane filter 251, a lower water collecting chamber (not shown) is provided in a state where the lower end is also opened like the upper end. A flow hole 254A through which the backwash air flows is formed in the lower joint portion 254, and the backwash air collected in the skirt portion 252B flows into the hollow fiber membrane module 25 through the flow hole 254A. It is. Further, flow holes 252C and 252D are formed slightly below the upper joint 253 and slightly above the lower joint 254 of the protective cylinder 252, respectively, and the high-pressure heater drain water is hollowed through these flow holes 252C and 252D. It flows into the yarn membrane module 25.
[0024]
By the way, since the above-mentioned moisture separator drain system and high-pressure feed water heater drain system both reach a high temperature of 100 to 300 ° C., the polymer material used for the hollow fiber membrane filter 251 has heat resistance to such high-temperature water. Is required. As a typical heat-resistant polymer material is formed of a heat-resistant polymer resin that does not substantially hydrolyze in high-temperature water, for example, polyether ketone, polytetrafluoroethylene, polyphenylene sulfide, Polymer compounds such as polysulfone, polyamide-based, polyimide-based, polyamideimide-based, dehydration polycondensation compounds such as polyetherimide-based, etc., but in the present embodiment, without considering thermal degradation, especially hydrolysis by high-temperature water must not. In consideration of this point, as the heat-resistant polymer resin, the former polyetherketone-based, polytetrafluoroethylene-based, polyphenylene sulfide-based, and polysulfone-based polymer compounds are preferable because they are particularly excellent in heat resistance in high-temperature water, Further, in consideration of workability into a film, polyetherketone and polytetrafluoroethylene are more preferable. In the present invention, being substantially not hydrolyzed in high-temperature water means not hydrolyzing at all in high-temperature water but slightly hydrolyzing when used in high-temperature water for a long time (for example, about 5 years). However, it means that a degree of hydrolysis that does not affect the filtration performance is included.
[0025]
Next, an embodiment of the method for operating the filtration tower of the present invention will be described. For example, immediately before receiving high-pressure heater drain water, the inside of the tower main body 21 of the filtration tower 20 is filled with water having a water temperature substantially equal to the ambient temperature. When filtering the high-pressure heater drain water in the filtration tower 20, the following operation is performed with the valve 15B of the bypass pipe 15A closed. First, after the gate valve 31 of the communication pipe 30 is fully opened, the valve 26A of the inflow pipe 26 and the valve 27A of the outflow pipe 27 are sequentially opened to guide the high-pressure heater drain water generated in the high-pressure heater 13 into the lower chamber 22. Then, the water held in the lower chamber 22 is gradually pushed out of the lower chamber 22 by the high-pressure heater drain water. At this time, since the flow resistance of the hollow fiber membrane module 25 is large, the water retained in the lower chamber 22 hardly passes through the hollow fiber membrane module 25 and gradually flows to the upper chamber 23 through the communication pipe 30 having a low flow resistance. It is pushed out and supplied to the deaerator 11.
[0026]
Since the lower chamber 22 and the upper chamber 23 communicate with each other through the communication pipe 30 by the above-described operation, the pressure in the lower chamber 22 and the pressure in the upper chamber 23 are substantially equal, and the pressure in the two chambers 22 and 23 is uniform. The temperature of the retained water in the lower chamber 22 and the upper chamber 23 gradually rises due to the high-pressure heater drain water flowing into the lower chamber 22 as well. When the pressures in the two chambers 22 and 23 become substantially uniform as described above, the gate valve 31 of the communication pipe 30 is closed, for example, by 20% and opened by 80%. The water in the lower chamber 22 is partially filtered by the hollow fiber membrane module 25, and the filtered water flows out to the upper chamber 23. At this time, since there is almost no pressure difference between the lower chamber 22 and the upper chamber 23, the hollow fiber membrane module 25 is not damaged, and the water pressure in the lower chamber 22 and the upper chamber 23 is high-pressure heater drain water. Since the pressure is higher than the saturated vapor pressure, the vapor does not adhere to the membrane surface of the hollow fiber membrane filter 251 in the hollow fiber membrane module 25, and the hollow fiber membrane module 25 functions normally, and the water in the lower chamber 22 Are filtered smoothly.
[0027]
Thereafter, the system waits for the entire amount of water in the lower chamber 22 to be replaced with the high-pressure heater drain water. When the entire amount of the water has been replaced, the gate valve 31 of the communication pipe 30 is gradually closed. When the pressure gradually increases and finally the gate valve 31 is fully closed, the high-pressure heater drain water is completely filtered by the hollow fiber membrane module 25. After the gate valve 31 is closed, the filtration tower 20 enters a steady operation state. When the operation of the filtration tower 20 is stopped, the gate valve 31 of the communication pipe 30 is opened prior to the stop. By this operation, the pressure between the lower chamber 22 and the upper chamber 23 can be made uniform to prevent the above-described generation of steam on the membrane surface and the like, and the next filtration process can be smoothly performed.
[0028]
The valve operation of the communication pipe 30 may be a manual operation or an automatic control operation by a controller. Further, when the high-pressure heater drain water is introduced into the filtration tower 20, the valve opening speed of the valve 26A of the inflow pipe 26 may be controlled to gradually increase the flow rate of the communication pipe 30.
[0029]
As described above, according to the present embodiment, since the communication pipe 30 that connects the lower chamber 22 and the upper chamber 23 in the tower main body 21 is provided and the gate valve 31 is provided in the communication pipe 30, the filtration of the high-pressure heater drain water is performed. Prior to the start of the operation, the gate valve 31 is opened and the lower chamber 22 and the upper chamber 23 are communicated with each other by the communication pipe 30, and then the high-pressure heater drain water is sequentially passed through the lower chamber 22 and the communication pipe 30 to the upper chamber 23. The pressure in the lower chamber 22 and the upper chamber 23 can be made uniform, so that there is no fear that excessive pressure is applied to the hollow fiber membrane module 25 when the high-pressure heater drain water is introduced. Loss Scratch can be prevented, and vapor is not generated on the membrane surface of the hollow fiber membrane module 25 or in micropores in the membrane, and the high-pressure heater drain water can be smoothly supplied without impairing the filtration function of the hollow fiber membrane module 25. The suspended matter can be reliably removed by filtration, and there is no danger of the hollow fiber membrane module 25 being dried.
[0030]
In addition, according to the present embodiment, the gate valve 31 is gradually closed from the fully open state to the fully closed state, so that the original filtration function is surely exerted while the load on the hollow fiber membrane module 25 is gradually increased. be able to. At this time, if the valve operation time for gradually closing the gate valve 31 from the fully opened state to the fully closed state is longer than the time required for replacing the water retained in the tower body 21 with the high-pressure heater drain water, the lower chamber 22 The water temperature in the inside does not rise at a stretch, and the generation of steam on the membrane surface of the hollow fiber membrane module 25 or the micropores in the membrane can be reliably prevented, and the original filtration function of the hollow fiber membrane module 25 is completely completed. Can be secured. Further, before the filtration of the high-pressure heater drain water is stopped, the pressure between the lower chamber 22 and the upper chamber 23 is made uniform by opening the gate valve 31 of the communication pipe 30, and the next filtration is smoothly performed. Can be.
[0031]
Next, a case where a polymer membrane filter made of the same heat-resistant polymer material as the hollow fiber membrane module 25 shown in FIG. 3 is applied to the filtration tower 50 having the structure shown in FIG. 4 will be described. As shown in the figure, for example, the filtration tower 50 has a partition plate 54 for dividing the inside of the tower main body 51 into a lower chamber 52 and an upper chamber 53, an upper end fixed to the partition plate 54, and an axis of the tower main body 51. A plurality of polymer membrane filter elements 55 disposed in the lower chamber 52 so as to hang down along the heart, an inflow pipe 56 connected to the lower chamber 52, and an outflow pipe 57 connected to the upper chamber 53. , Except for the polymer material of the membrane filter of the polymer membrane filter element 55, in accordance with a conventional filtration tower. 56A is a valve of the inflow pipe 56, 57A is a valve of the outflow pipe 57, 58 is a mother pipe of raw water, 59 is a mother pipe of filtered water, 60 is a bypass pipe, and 60A is a valve of the bypass pipe 60.
[0032]
The polymer membrane filter element 55 used in the filtration tower 50 of the present embodiment has a polymer membrane filter formed of the same heat-resistant polymer material as in the above embodiment, and the polymer membrane filter is, for example, a hollow fiber membrane. Molded, pleated and spiral shaped. By using such a polymer membrane filter element 55, the original filtration performance can be maintained in high-temperature water without being subjected to hydrolysis of the membrane filter by high-temperature water.
[0033]
In the case where high-temperature water such as heater drain water having a temperature of 100 ° C. or more is filtered to remove suspended substances by using the filtration tower of the present embodiment, the inflow pipe is first opened with the valve 60A of the bypass pipe 60 closed. After gradually opening the valve 56A of 56 and the valve 57A of the outflow pipe 57 and gradually supplying high-temperature water from the inflow pipe 56 into the lower chamber 52 to gradually increase the water pressure in the lower chamber 22 and replace the retained water, Enter regular operation. Here, if it is attempted to replace the retained water with high-temperature water at once, an excessively large differential pressure is applied to the polymer membrane filter element 55 at a stretch, and the polymer membrane filter element 55 may be damaged, which is not preferable.
[0034]
If high-temperature water is introduced into the lower chamber 52 at once, an excessively large differential pressure is applied to the polymer membrane filter element 55 at a stretch, and the polymer membrane filter element 55 may be damaged. Further, when the internal pressure of the lower chamber 52 and the upper chamber 53 is lower than the saturated vapor pressure of the high-temperature water when the high-temperature water is introduced into the lower chamber 52, steam is generated in the lower chamber 52 and the polymer membrane filter element is formed. As a result, the fine pores of the polymer membrane filter element 55 are blocked by steam, the effective filtration area is reduced, and the pressure difference between the lower chamber 52 and the upper chamber 53 is further increased, and There is a concern that the membrane filter element 55 may be damaged. Further, once dried, the polymer membrane filter element 55 has a property that the filtration function is significantly impaired. Therefore, for example, as described above, when the saturated vapor pressure on the filtered water side is lower than the saturated vapor pressure on the raw water side which is high-temperature water due to the membrane differential pressure, the system differential pressure, or the water temperature in the initial stage of water passage as described above. , High-temperature water generates steam in the micropores on the membrane surface or in the film thickness part of the polymer membrane filter, closes the pores, and the heat of the steam dries the polymer membrane filter, losing the filtration function of the polymer membrane filter There is a risk of doing so. Therefore, the filtration tower 50 may be operated while the internal pressure of the lower chamber 52 and the upper chamber 53 is set higher than the saturated vapor pressure of the high-temperature water while gradually replacing the retained water with the high-temperature water.
[0035]
In the above embodiment, the high-temperature water system of the condensate such as the high-pressure heater drain water and the moisture separator drain water of the power plant as the raw water has been described as an example. The present invention can be preferably applied to a case where high-temperature water is filtered, and can be widely applied to other than high-temperature water. When a communication pipe is provided in the filtration tower, an overload on the polymer membrane filter can be reduced in the initial stage of water flow to the filtration tower, and damage to the polymer membrane filter can be prevented. Further, the case where the hollow fiber membrane module 25 is used as the polymer membrane filter element has been described, but it is also possible to use a pleated polymer membrane filter, a spiral polymer membrane filter, or the like as the polymer membrane filter element. Not even. Further, the operation method of the filtration tower 20 is not limited to the above embodiment.
[0036]
【The invention's effect】
According to the first aspect of the present invention, for example, high-temperature water such as heater drain water Even when filtration is performed, damage to the polymer membrane filter element can be prevented at the start of the filtration operation, water can flow smoothly without impairing the filtration function of the polymer membrane filter element, and suspension in high-temperature water can be performed. Efficient removal of suspended matter A filtration tower that can be provided.
[0037]
In addition, according to the invention described in claims 2 to 6 of the present invention, even when high-temperature water such as heater drain water is filtered, , Preventing damage to the polymer membrane filter element at the start of operation, Filtration that allows water to flow smoothly without impairing the filtration function of the polymer membrane filter element and efficiently removes suspended substances in high-temperature water Of the tower Providing driving methods Can .
[Brief description of the drawings]
FIG. 1 is a flowchart showing a power plant to which a filtration tower of the present invention is applied.
FIG. 2 is a configuration diagram showing one embodiment of a filtration tower of the present invention applied to the power plant shown in FIG.
FIG. 3 is a cross-sectional view showing a hollow fiber membrane module used as a polymer membrane filter element of the filtration tower shown in FIG.
FIG. 4 shows the filtration tower of the present invention. Filtration tower that can be suitably used for the operation method FIG.
[Explanation of symbols]
20, 50 filtration tower
21, 51 Tower body
22, 52 Lower chamber
23, 53 Upper room
24, 54 Partition plate
25, 55 Hollow fiber membrane module (polymer membrane filter element)
26, 56 Inflow pipe
27, 57 Outflow pipe
30 communicating pipe
31 Gate valve

Claims (6)

A partition plate for partitioning the inside of the tower body into a lower chamber and an upper chamber; and a plurality of polymer membrane filter elements having ends fixed to the partition plate and disposed in the lower chamber along the axis of the tower body. A filtration tower that filters the raw water flowing into the lower chamber by the inflow pipe through each of the polymer membrane filter elements, and allows the filtered water collected in the upper chamber to flow out of the outflow pipe. A filtration tower wherein only the upper chamber is connected by a communication pipe and a gate valve is provided in the communication pipe. A partition plate for partitioning the inside of the tower body into a lower chamber and an upper chamber; and a plurality of polymer membrane filter elements having ends fixed to the partition plate and disposed in the lower chamber along the axis of the tower body. And a communication pipe for connecting the lower chamber and the upper chamber, and a method of operating a filtration tower including a gate valve provided in the communication pipe, and starting filtration of raw water using the filtration tower. Prior to doing so, after opening the gate valve and communicating the lower chamber and the upper chamber by the communication pipe, the raw water is supplied to the upper chamber through the lower chamber and the communication pipe sequentially, A method for operating a filtration tower, wherein pressures in the lower chamber and the upper chamber are equalized. The method for operating a filtration tower according to claim 2 , wherein high-temperature water of 100C or more is used as the raw water. The method according to claim 2 or 3 , wherein the gate valve is gradually closed from a fully opened state to a fully closed state. Claims, characterized in that the valve operating time from the fully open state to gradually closed to the fully closed state gate valve, the holdings water of at least the tower body be longer than the time required for replacing the above raw water 5. The method for operating the filtration tower according to 4 . The filtration of the raw water prior to the stop, the method of driving the filtration tower according to any one of claims 2 to 5 you, wherein opening the gate valve of the communicating pipe.

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