Ion removal device, ion removal method, and flash evaporation device

Abstract

To efficiently remove various impurity ions by placing an ion removal apparatus applicable from room temperature to high temperature in each evaporation chamber.SOLUTION: An ion removal apparatus 2 includes an adsorbent packing part 4 filled with a first adsorbent material 3 made of either titanium or niobium or a mixture thereof, a liquid supply port 5a where liquid containing impurity ions is supplied to the adsorbent packing part, and a liquid outlet 5b where liquid after treatment is discharged from the adsorbent packing part.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] An embodiment of the present invention relates to an ion removal device, an ion removal method, and a flash evaporation device for removing impurity ions contained in a liquid. [Background technology]

[0002] For example, a multi-stage flash evaporator is used as a means of desalinating seawater. In this flash evaporator, heated seawater is sent to multiple evaporation chambers with successively increasing degrees of pressure reduction, and fresh water is produced by repeating evaporation and cooling in each stage and separating the steam and liquid in a demister. Since the fresh water produced is distilled water, it is highly safe and is widely used as water for daily life.

[0003] However, the fresh water produced may contain impurity ions, such as sodium ions and chloride ions derived from seawater, and metal ions, such as iron, copper, and nickel, that have leached from metal components that make up the equipment and piping. Therefore, a method has been proposed for removing these impurity ions by placing an adsorbent material, such as a membrane, ion exchange resin, inorganic adsorbent, activated carbon, or the like, at the outlet of the flash evaporator. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 61-61690 [Patent Document 1] JP 2006-70889 A Summary of the Invention [Problem to be solved by the invention]

[0005] As described above, a flash evaporation apparatus that has an impurity ion removal device at the outlet has been proposed in order to remove impurity ions. However, this has the problem that the apparatus becomes large in size and the maintenance work burden for regenerating and replacing the adsorbent becomes large.

[0006] One possible method to remove impurity ions is to place an adsorbent in each evaporation chamber of the flash evaporation device; however, the first evaporation chamber generally reaches a high temperature of 120°C or more, making it difficult to use conventional adsorbents such as ion exchange resins, which are used at temperatures below approximately 60°C.

[0007] In order to solve the above-mentioned problems, the inventors conducted extensive research and discovered that some adsorbents are capable of removing impurity ions even at high temperatures, which led to the present invention. Specifically, it is an object of the present invention to provide an ion removal device, ion removal method, and flash evaporation device that are compact and have high removal efficiency, which can efficiently remove various impurity ions by making it possible to place an adsorbent in each evaporation chamber. [Means for solving the problem]

[0008] In order to solve the above problems, the ion removal device according to the present embodiment has an adsorbent-filled section filled with a first adsorbent made of either titanium or niobium or a mixture thereof, a liquid supply port through which a liquid containing impurity ions is supplied to the adsorbent-filled section, and a liquid discharge port through which the treated liquid is discharged from the adsorbent-filled section. A demister is disposed between the adsorbent-filled section and a liquid supply port, and between the adsorbent-filled section and a liquid discharge port. do.

[0009] In addition, the ion removal method according to this embodiment uses the ion removal device of this embodiment to adsorb and remove impurity ions in a liquid.

[0010] In addition, the flash evaporator according to the present embodiment is a multi-stage flash evaporator in which a plurality of evaporation chambers are arranged adjacent to each other. The evaporation chambers are provided with a seawater storage section at the bottom, and a storage section for storing impurity ions in the steam generated in the evaporation chambers. In the adsorbent filling section Adsorb and remove The method according to claim 1 The system includes an ion removal device, a cooling pipe for condensing steam that has passed through the ion removal device, a freshwater storage section for storing the condensed freshwater, and a freshwater recovery pipe for recovering the freshwater from the freshwater storage section. Effect of the Invention

[0011] According to this embodiment, by disposing an adsorbent in each evaporation chamber, it is possible to provide a compact ion removal device, ion removal method, and flash evaporation device that can efficiently remove various impurity ions and have high removal efficiency. [Brief description of the drawings]

[0012] [Figure 1] FIG. 2 is a schematic diagram of the ion removal device (without a demister) according to the first embodiment. [Diagram 2] FIG. 2 is a schematic diagram of an ion removal device (with a demister) according to the first embodiment. [Diagram 3] FIG. 1 is a configuration diagram of a flash evaporation device according to a first embodiment. [Figure 4] FIG. 4 is a graph showing the results of a performance test of the ion removal device according to the first embodiment. [Diagram 5] FIG. 5 is a configuration diagram of a flash evaporation device according to a second embodiment. [Figure 6] FIG. 11 is a configuration diagram of a flash evaporation device according to a third embodiment. [Figure 7] FIG. 13 is a configuration diagram of a flash evaporation device according to a fourth embodiment. [Figure 8] FIG. 13 is a configuration diagram of a flash evaporation device according to a fifth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of an ion removal device, an ion removal method, and a flash evaporation device according to the present invention will be described with reference to the drawings.

[0014] [First embodiment] An ion removal device, an ion removal method, and a flash evaporation device according to a first embodiment will be described with reference to FIGS. 1 to 4. FIG.

[0015] (Configuration of ion removal device) FIG. 1 is a schematic diagram of an ion removal device 1 (without demister) filled with adsorbent 3, and comprises a liquid supply port 5a to which liquid containing impurity ions is supplied, an adsorbent filling section 4 which is filled with, for example, granular adsorbent 3, and a liquid discharge port 5b from which the liquid after the impurity ions have been removed is discharged. The liquid supply port 5a and the liquid discharge port 5b are formed, for example, from a mesh-like or net-like metal or ceramic plate.

[0016] FIG. 2 is a schematic diagram of an ion removal device 2 (with demister) equipped with a demister (gas-liquid separation section) 6, in which a mesh-like demister (gas-liquid separation section) 6 that separates liquid and vapor is disposed between the liquid supply port 5a and the adsorbent filled section 4, and between the liquid discharge port 5b and the adsorbent filled section 4. These ion removal devices 1 and 2 can be used not only as the multi-stage flash evaporation device 10 but also as a general impurity ion removal device.

[0017] (Adsorbent) As the adsorbent 3, a newly developed adsorbent 3a (first adsorbent) made of either titanium or niobium or a mixture thereof applicable at room temperature to approximately 280°C, and / or an adsorbent 3b (second adsorbent) made of a known ion exchange resin, activated carbon, inorganic adsorbent, etc. applicable at room temperature to approximately 60°C is used.

[0018] In particular, in the evaporation chamber of the flash evaporation device 10 to which high-temperature seawater of 120° C. or more is supplied, it is desirable to use the adsorbent 3a (see FIG. 6) that is applicable even at high temperatures.

[0019] The adsorbent 3a can efficiently adsorb and remove impurity ions, particularly metal ions such as alkali metal ions, alkaline earth metal ions, and transition metal ions such as cobalt ions, iron ions, and nickel ions.

[0020] The adsorbent 3b is made of a known ion exchange resin, activated carbon, inorganic adsorbent, or the like that is applicable at room temperature to about 60° C., and adsorbs and removes impurity ions such as sodium ions and chloride ions contained in seawater.

[0021] These adsorbents 3a and 3b are used in the evaporation chambers 7 to 9 of a multi-stage flash evaporation apparatus 10 as described later. The adsorbents 3a and 3b are in the form of particles of about 0.1 to several millimeters.

[0022] (Configuration of flash evaporation device) FIG. 3 is a configuration diagram of a multi-stage flash evaporation apparatus 10 incorporating the ion removal apparatus 2 (with demister) shown in FIG.

[0023] The flash evaporation apparatus 10 of this embodiment has, for example, three stages of evaporation chambers 7, 8, and 9 arranged adjacent to each other, and each evaporation chamber 7-9 has a demister 6 that separates the steam generated in the evaporation chamber into gas and liquid, an ion removal device 2 equipped with an adsorbent 3 that removes impurity ions, a cooling pipe 11 that condenses the steam that has passed through the ion removal device 2 with cooling water such as seawater to produce fresh water, a freshwater storage section 12 that stores the produced fresh water, a freshwater recovery pipe 14 that recovers the fresh water, and a seawater supply pipe 15 that supplies heated seawater to the seawater storage section 13 of each evaporation chamber 7-9. Although FIG. 3 shows an example in which the evaporation chamber has three stages, it may have four or more stages.

[0024] (action) In the multi-stage flash evaporation apparatus 10 configured as described above, first, heated seawater is supplied to the first-stage evaporation chamber 7 through the seawater supply pipe 15 and evaporated. The generated steam moves upward in the evaporation chamber 7 and passes through the ion removal device 2 having the demister 6. During this process, impurity ions mixed in the steam are removed by the adsorbent 3, and then gas-liquid separation is performed by the demister 6. The passed steam is cooled by the cooling pipe 11 to become fresh water, which is then stored in the fresh water storage section 12.

[0025] Next, the seawater that has not evaporated in the first-stage evaporation chamber 7 is sent to the second-stage evaporation chamber 8, which has a higher degree of vacuum, and evaporated, producing fresh water in the same manner as in the first-stage evaporation chamber 7. This process is repeated in the subsequent evaporation chambers 9, and finally the fresh water stored in the fresh water storage section 12 of each of the evaporation chambers 7-9 is recovered to the outside through the fresh water recovery pipe 14.

[0026] As the adsorbent 3, a newly developed adsorbent 3a made of either titanium or niobium or a mixture thereof that is applicable at room temperature to about 280°C, and / or an adsorbent 3b made of a known ion exchange resin, activated carbon, inorganic adsorbent, or the like that is applicable at room temperature to about 60°C is used. In particular, it is desirable to use the adsorbent 3a made of either titanium or niobium or a mixture thereof as the adsorbent 3 filled in the ion removal device 2 in the first-stage evaporation chamber 7 to which seawater at 120°C or higher is supplied.

[0027] In addition, in the second and subsequent evaporation chambers 8 and 9 where the temperature drops, the adsorbent 3b may be used or the adsorbent 3b may be used in combination. Furthermore, since it is possible that the first evaporation chamber 7 does not reach a high temperature, the adsorbents 3a and 3b may be used in combination.

[0028] These adsorbents 3a and 3b can efficiently adsorb and remove metal ions and various impurity ions such as sodium ions and chloride ions.

[0029] (Performance test) The adsorption performance of the adsorbent 3a (titanium or niobium or a mixture thereof) was tested by passing a divalent metal cation solution at a concentration of 10 ppm at a flow rate of 0.80 ml / min in a high temperature environment of 280°C.

[0030] FIG. 4 shows the performance test results, with the horizontal axis representing BV (bed volume; water flow rate / adsorbent amount) and the vertical axis representing the ion removal ratio (outlet concentration of metal cations / inlet concentration).

[0031] From FIG. 4, the adsorbent 3a has a distribution coefficient of about 6×10 3It was found that the ion removal ratio remained almost zero up to about 10,100 BV, that is, about 100% of the ions were adsorbed and removed.

[0032] In the performance test shown in FIG. 4, the test was performed using an ion-containing solution at 280°C, but it was confirmed that the removal performance was almost the same in the range of room temperature to 280°C.

[0033] Generally, the temperature of seawater supplied to the first-stage evaporation chamber 7 of a flash evaporation device is approximately 120°C, and the adsorbent 3a developed this time can be used at temperatures from room temperature to high temperatures below 280°C. Therefore, it is possible to install an ion removal device filled with this adsorbent 3a in the evaporation chambers from the first stage to the final stage.

[0034] The evaporation chambers 7 to 9 have a tendency for the temperature to decrease going downward. In particular, in the evaporation chambers in the lower stages, in addition to the adsorbent 3a that adsorbs and removes metal ions, the adsorbent 3b made of an ion exchange resin, activated carbon, an inorganic adsorbent, or the like can be used alone or in combination with the adsorbent 3a.

[0035] Furthermore, a conventional ion removal device may be provided at the outlet of the flash evaporation device 10 in combination, and the ion removal devices 2 need not be provided in all of the evaporation chambers 7 to 9, and may be omitted in part.

[0036] (effect) As described above, according to the first embodiment, by providing an ion removal device 2 filled with an adsorbent 3a that can be used at higher temperatures in at least one of the evaporation chambers 7-9, it is possible to efficiently adsorb and remove metal ions in particular and to reduce the size of the entire device.

[0037] In addition, by using an adsorbent 3b made of an ion exchange resin, activated carbon, an inorganic adsorbent, or the like in each of the evaporation chambers 7 to 9, or using it alone, impurity ions derived from seawater, such as sodium ions and chloride ions, can also be adsorbed and removed.

[0038] [Second embodiment] An ion removal device, an ion removal method, and a flash evaporation device according to a second embodiment will be described with reference to FIG.

[0039] In the second embodiment, assuming that the ion removal device 2 shown in FIG. 3 is unable to adsorb and remove all impurity ions or that metal ions are generated from piping or the like in the evaporation chambers 7 to 9, an ion removal device 1 (without a demister) is additionally provided in each of the evaporation chambers 7 to 9.

[0040] In the example shown in FIG. 5, the ion removal device 1 is provided above the fresh water storage section 12 and in a fresh water recovery pipe 14 extending from the fresh water storage section 12.

[0041] As a result, the steam discharged from the liquid outlet 5b of the ion removal device 2 further adsorbs and removes impurity ions in the ion removal device 1 provided above the freshwater storage section 12, and the ion removal device 1 provided in the freshwater recovery piping 14 downstream of the freshwater storage section 12 adsorbs and removes impurity ions contained in the freshwater in the freshwater recovery piping 14.

[0042] According to the second embodiment, by providing a plurality of ion removal devices 1 and 2 in the evaporation chamber, it is possible to further improve the efficiency of adsorption and removal of impurity ions.

[0043] The ion removal device provided above the fresh water storage section 12 may be an ion removal device 2 (with a demister). In addition, in the example of FIG. 5, a plurality of ion removal devices 1, 2 are provided in each of the evaporation chambers 7 to 9, but the present invention is not limited to this and may be omitted as appropriate.

[0044] [Third embodiment] An ion removal device, an ion removal method, and a flash evaporation device according to a third embodiment will be described with reference to FIG.

[0045] In the third embodiment, an ion removal device 2a filled with an adsorbent 3a or an ion removal device 2b filled with an adsorbent 3b is disposed in each of the evaporation chambers 7 to 9.

[0046] As described above, the temperatures of the evaporation chambers 7-9 decrease as they go down, so in the example shown in Figure 6, an ion removal device 2a filled with an adsorbent 3a that is applicable from room temperature to 280°C is installed in the first evaporation chamber 7, and an ion removal device 2b filled with an adsorbent 3b that is applicable from room temperature to 60°C is installed in the evaporation chambers 8 and 9 from the second stage onwards.

[0047] In this way, by installing the ion removal devices 2a, 2b filled with the appropriate adsorbents 3a, 3b according to the temperature environment in the evaporation chambers 7-9, various kinds of impurity ions can be efficiently adsorbed and removed.

[0048] Note that, as in the second embodiment, these ion removal devices 2a and 2b may be additionally provided above the fresh water storage section 12 or on the fresh water recovery pipe 14 extending from the fresh water storage section 12.

[0049] [Fourth embodiment] An ion removal device, an ion removal method, and a flash evaporation device according to a fourth embodiment will be described with reference to FIG.

[0050] In the fourth embodiment, an ion removal device 2a filled with an adsorbent 3a and an ion removal device 2b filled with an adsorbent 3b are disposed in each of the evaporation chambers 7 to 9.

[0051] In the example shown in FIG. 7, an ion removal device 2b filled with an adsorbent 3b applicable from room temperature to 60°C is installed in each of the evaporation chambers 7 to 9, and an ion removal device 2a filled with an adsorbent 3a applicable from room temperature to 280°C is installed above it.

[0052] That is, seawater at 120°C or higher is usually supplied to the first stage evaporation chamber 7, but it is expected that seawater at close to room temperature may be supplied in some cases, so two types of ion removal devices 2a, 2b capable of adsorbing and removing various ionic impurities are arranged in each of the evaporation chambers 7-9.

[0053] In this way, by installing the ion removal devices 2a and 2b in the evaporation chambers 7 to 9, various kinds of impurity ions can be efficiently adsorbed and removed even if the temperature environment changes.

[0054] [Fifth embodiment] An ion removal device, an ion removal method, and a flash evaporation device according to a fifth embodiment will be described with reference to FIG.

[0055] In the fifth embodiment, each of the evaporation chambers 7 to 9 is configured such that an adsorbent 3a that is applicable from room temperature to 280° C. and an adsorbent 3b that is applicable from room temperature to 60° C. are mixed and filled in one ion removal device 2.

[0056] This allows various kinds of impurity ions to be efficiently adsorbed and removed in each of the evaporation chambers 7 to 9 even if the temperature environment changes, and also allows the ion removal device 2 to be made compact.

[0057] Although several embodiments of the present invention have been described above, these embodiments are presented as examples and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, substitutions, modifications, and combinations can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope of the invention and its equivalents described in the claims, as well as in the scope and spirit of the invention. [Explanation of symbols]

[0058] 1...Ion removal device (without demister), 2, 2a, 2b...Ion removal device (with demister), 3, 3a, 3b...Adsorbent, 4...Adsorbent filling section, 5a...Liquid supply port, 5b...Liquid discharge port, 6...Demister, 7-9...Evaporation chamber, 10...Flash evaporation device, 11...Cooling piping, 12...Freshwater storage section, 13...Seawater storage section, 14...Freshwater recovery piping, 15...Seawater supply piping

Claims

1. An ion removal device comprising: an adsorbent-filled section filled with a first adsorbent made of either titanium or niobium or a mixture thereof; a liquid supply port through which a liquid containing impurity ions is supplied to said adsorbent-filled section; and a liquid discharge port through which treated liquid is discharged from said adsorbent-filled section, with demisters disposed between said adsorbent-filled section and the liquid supply port, and between said adsorbent-filled section and the liquid discharge port.

2. 2. The ion removal device according to claim 1, wherein the first adsorbent is applicable in a temperature range from room temperature to 280[deg.] C. and adsorbs and removes alkali metal ions, alkaline earth metal ions, or transition metal ions.

3. 3. The ion removal device according to claim 2, wherein the transition metal ions are cobalt ions, iron ions or nickel ions.

4. 4. An ion removal method for adsorbing and removing impurity ions from a liquid, using the ion removal device according to claim 1.

5. In a multi-stage flash evaporation apparatus having a plurality of evaporation chambers arranged adjacent to each other, The evaporation chamber is provided with a seawater storage section at a lower portion thereof, an ion removal device as described in claim 1 which adsorbs and removes impurity ions in the steam generated in the evaporation chamber using an adsorbent filled section, a cooling pipe which condenses the steam which has passed through the ion removal device, a freshwater storage section which stores the condensed freshwater, and a freshwater recovery pipe which recovers the freshwater from the freshwater storage section.

6. 6. A flash evaporation apparatus as described in claim 5, wherein the adsorbent filling section is filled with a first adsorbent consisting of either titanium or niobium or a mixture thereof, or a second adsorbent consisting of an ion exchange resin, activated carbon or an inorganic adsorbent.

7. 6. A flash evaporation apparatus as described in claim 5, wherein a first adsorbent consisting of either titanium or niobium or a mixture thereof and a second adsorbent consisting of an ion exchange resin, activated carbon or an inorganic adsorbent are mixed and filled in the adsorbent filling section.

8. 6. A flash evaporation apparatus according to claim 5, in which an ion removal device having an adsorbent packed section filled with a first adsorbent made of either titanium or niobium or a mixture thereof, and an ion removal device having an adsorbent packed section filled with a second adsorbent made of an ion exchange resin, activated carbon or an inorganic adsorbent are arranged adjacent to each other vertically.

9. 6. A flash evaporation apparatus as described in claim 5, wherein an ion removal device having an adsorbent filled section filled with a first adsorbent consisting of either titanium or niobium or a mixture thereof is disposed in a first evaporation chamber, and an ion removal device having an adsorbent filled section filled with a second adsorbent consisting of an ion exchange resin, activated carbon or an inorganic adsorbent is disposed in a second or subsequent evaporation chamber.

10. A flash evaporation apparatus as described in any one of claims 5 to 9, further comprising an ion removal device having an adsorbent filled section filled with a first adsorbent consisting of either titanium or niobium or a mixture thereof, above the fresh water storage section and / or the fresh water recovery pipe, or an ion removal device having an adsorbent filled section filled with a second adsorbent consisting of an ion exchange resin, activated carbon or an inorganic adsorbent.

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