JP4896929B2 - Seawater desalination system and system - Google Patents

Description

  The present invention relates to an apparatus and system for desalinating seawater.

For example, in Patent Document 1, an electric double layer capacitor containing pasty activated carbon is immersed in saline, an electric field is applied to the electric double layer capacitor, and sodium ions and chlorine ions of saline are adsorbed on the pasty activated carbon, resulting in a low concentration. The salt water (fresh water) is taken out.
JP 2003-285066 A

Since the desalination apparatus of the above-mentioned patent document 1 is a batch type, efficiency is not improved and the production amount of fresh water is bad.
This invention is made | formed in view of the said matter, and aims at desalinating seawater efficiently.

In order to solve the above problems, a desalination apparatus according to the present invention includes:
An apparatus main body having a flow path for mixing and flowing activated carbon powder in seawater;
A first filter which is accommodated in the apparatus main body so as to partition the flow path into first and second regions parallel to each other, and allows permeation of seawater and prevents permeation of activated carbon powder;
A first electrode provided in the first region;
A second electrode provided in the second region so as to face the first electrode across the first filter;
A direct current power source for setting the first electrode to a higher potential than the second electrode in a range where seawater is not electrolyzed;
A first extraction port connected to the flow path downstream from the first electrode and the second electrode;
A second filter that is provided at the first outlet and allows seawater to pass therethrough and prevents activated carbon powder from passing through;
It is provided with.
According to this characteristic configuration, the activated carbon powder is positively charged by the first electrode, and chlorine ions in seawater in the first region are adsorbed to the activated carbon powder. Further, chlorine ions in the seawater in the second region pass through the first filter and are adsorbed on the positively charged activated carbon powder. Further, the activated carbon powder is negatively charged at the second electrode, and sodium ions in the seawater in the second region are adsorbed to the activated carbon powder. Furthermore, sodium ions in seawater in the first region pass through the first filter and are adsorbed on the negatively charged activated carbon powder. Thereby, seawater can be desalinated efficiently. Here, not only sodium ions (Na ⁺ ) and chlorine ions (Cl ⁻ ) but also magnesium ions (Mg ⁺ ) and sulfate ions (SO ₄ ²⁻ ) exist in seawater. These ions behave similarly to sodium ions and chlorine ions.

The first outlet is disposed in an intermediate portion of the flow path, and the first filter and thus the first and second regions extend downstream from the intermediate portion of the flow path;
A third electrode provided in a first region downstream of the first outlet,
A fourth electrode provided in a second region downstream of the first extraction port so as to face the third electrode across the first filter;
Preferably, wiring is performed so that current flows out from the third electrode and current flows into the fourth electrode.
A high electromotive force is generated between the third electrode and the fourth electrode with respect to the fourth electrode. At this time, since there is a current flowing out from the third electrode and a current flowing into the fourth electrode, chlorine ions can be released from the activated carbon powder in the third electrode, and from the activated carbon powder in the fourth electrode. Sodium ions can be released.

In order to allow a current to flow out from the third electrode and to allow a current to flow into the fourth electrode, a wiring structure in which the third electrode and the fourth electrode are short-circuited may be used, but the following wiring structure is preferably employed.
That is, the positive electrode of the DC power supply is connected to the first electrode, the negative electrode of the DC power supply is connected to the third electrode, and the second electrode and the fourth electrode are short-circuited, or the DC It is preferable that a positive electrode of a power supply is connected to the fourth electrode, a negative electrode of the DC power supply is connected to the second electrode, and the first electrode and the third electrode are short-circuited.
As a result, current can flow out from the third electrode and current can flow into the fourth electrode. In addition, the voltage of the DC power supply can be lowered by the amount of electromotive force generated between the third and fourth electrodes. Thereby, power efficiency can be improved.

The desalination apparatus, a second extraction port connected to the downstream end of the flow path;
A third filter that is provided at the second outlet and allows seawater to pass therethrough and prevents activated carbon powder from passing through;
A recovery path for returning the activated carbon powder from the downstream end to the upstream end of the flow path;
Is preferably further provided.
Thereby, activated carbon powder can be reused.

It is preferable that the first electrode allows permeation of seawater and activated carbon powder. Thereby, the contact frequency of activated carbon powder to the 1st electrode can be raised, and positive charge of activated carbon powder and adsorption | suction of a chlorine ion can be caused efficiently.
It is preferable that the second electrode allows permeation of seawater and activated carbon powder. Thereby, the contact frequency of the activated carbon powder to the second electrode can be increased, and negative charging of the activated carbon powder and adsorption of sodium ions can be efficiently caused.
It is preferable that the third electrode allows permeation of seawater and activated carbon powder. Thereby, the contact frequency to the 3rd electrode of the activated carbon powder which adsorb | sucked the chlorine ion can be raised, and collection | recovery of positive charge and detachment | leave of a chlorine ion can be caused efficiently.
It is preferable that the fourth electrode allows permeation of seawater and activated carbon powder. Thereby, the contact frequency to the 4th electrode of the activated carbon powder which adsorb | sucked the sodium ion can be raised, and collection | recovery of a negative charge and detachment | leave of a sodium ion can be caused efficiently.

The first electrode is preferably made of metal wool. Thereby, seawater and activated carbon powder can be reliably transmitted through the first electrode.
The second electrode is preferably made of metal wool. Thereby, seawater and activated carbon powder can be reliably transmitted through the second electrode.
The third electrode is preferably made of metal wool. Thereby, seawater and activated carbon powder can be surely transmitted through the third electrode.
The fourth electrode is preferably made of metal wool. Thereby, seawater and activated carbon powder can be surely transmitted through the fourth electrode.

The first filter is preferably an insulator. It is preferable that the first electrode is in contact with the first filter. It is preferable that the second electrode is in contact with the first filter. It is preferable that the third electrode is in contact with the first filter. It is preferable that the fourth electrode is in contact with the first filter.
Thereby, the resistance at the time of a chlorine ion or sodium ion moving between 1st, 2nd area | regions via a 1st filter can be made small.

It is preferable that the first electrode is filled in the entire flow section of the first region. Thereby, the whole mixed fluid of seawater and activated carbon powder passing through the first region can be transmitted through the inside of the first electrode, and a reaction at the first electrode can be sufficiently ensured.
It is preferable that the second electrode is filled in the entire flow section of the second region. Thereby, the whole mixed fluid of seawater and activated carbon powder passing through the second region can pass through the inside of the second electrode, and the reaction at the second electrode can be sufficiently ensured.
It is preferable that the third electrode is filled in the entire flow section of the first region. Thereby, the whole mixed fluid of seawater and activated carbon powder passing through the first region can pass through the inside of the third electrode, and the reaction at the third electrode can be sufficiently ensured.
It is preferable that the fourth electrode is filled in the entire flow section of the second region. Thereby, the whole mixed fluid of seawater and activated carbon powder passing through the second region can pass through the inside of the fourth electrode, and the reaction at the fourth electrode can be sufficiently ensured.

The desalination system according to the present invention is characterized in that the desalination apparatus includes a plurality of stages, and the first extraction port of the front stage desalination apparatus is connected to the upstream end of the flow path of the rear stage desalination apparatus.
According to this characteristic configuration, high-quality fresh water can be obtained by sequentially passing seawater through a plurality of stages of desalination apparatuses and proceeding with desalination for each stage.
You may provide the desalination apparatus of a reverse osmosis membrane method in the back | latter stage of this desalination apparatus. If it does so, in this desalination apparatus, the salt concentration in seawater can be reduced and the osmotic pressure of seawater can be reduced significantly. For this reason, in the latter stage reverse osmosis membrane method desalination apparatus, the pressurization pressure may be low, which contributes to the durability of the membrane and simplification of the pressurization apparatus.

  According to the present invention, seawater can be efficiently desalinated.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
As shown in FIG. 3, the seawater desalination system S includes a plurality of seawater desalination apparatuses 1, 1. These desalination apparatuses 1, 1... Are connected in series to form a cascade.

  As shown in FIG. 1, each desalination apparatus 1 includes an apparatus main body 10, a DC power supply 20, and electrodes 31 to 34.

  The apparatus main body 10 is preferably made of a salt water-resistant resin (insulator) and has a vertically long container shape. As shown in FIG. 2, the cross section of the apparatus main body 10 is a square, but is not limited thereto, and may be a circular cross section or a polygonal cross section other than a square.

  As shown in FIG. 1, the internal space of the apparatus main body 10 is a flow path 11. A seawater supply port 12 is provided on a wall at one end in the longitudinal direction of the apparatus main body 10 (upstream end wall, upper in FIG. 1). As shown in FIGS. 1 and 3, a seawater supply path 51 is connected to the supply port 12 of the first-stage desalination apparatus 1. Seawater is supplied into the flow path 11 from the supply port 12 through the supply path 51. Activated carbon powder 92 is mixed in the seawater in the flow path 11. The average particle diameter of the activated carbon powder 92 is, for example, 10 to 1000 μm.

A first filter 41 is provided in the interior 11 of the apparatus body 10. The first filter 41 is constituted by a filter made of a resin (insulator) such as cellulose or Teflon (registered trademark), for example, and allows permeation of seawater and prevents permeation of activated carbon powder. The size of the first filter 41 is formed to be smaller than the particle size of the activated carbon powder 92, for example, in the range of about 0.5 to 500 μm. The thickness of the first filter 41 is, for example, about 10 to 50 μm.
Filter paper may be used as the first filter 41.

  The first filter 41 extends in the longitudinal direction of the apparatus main body 10 (up and down in FIG. 1). As shown in FIG. 1, both end portions of the first filter 41 in the longitudinal direction do not reach the end walls on the same side in the longitudinal direction of the apparatus body 10, but are slightly separated from the end walls. As shown in FIG. 2, both end portions in the width direction of the first filter 41 reach the peripheral wall of the apparatus main body 10. As shown in FIGS. 1 and 2, the flow path 11 is partitioned into a first region 13 and a second region 14 by the first filter 41. As shown in FIG. 1, the first and second regions 13 and 14 extend in the longitudinal direction of the apparatus body 10 in parallel with each other.

  The first electrode 31 is accommodated in a portion upstream of the intermediate portion of the first region 13 (upper in FIG. 1). The first electrode 31 is made of, for example, stainless wool. Not only seawater but also activated carbon powder 92 can pass through the first electrode 31. As shown in FIG. 2, the first electrode 31 is filled in the entire flow section of the first region 13. The peripheral surface of the first electrode 31 is in close contact with the first filter 41 and the inner surface of the apparatus main body 10.

  The second electrode 32 is accommodated in a portion upstream of the intermediate portion of the second region 14. The second electrode 32 is made of, for example, stainless wool like the first electrode 31 and allows permeation of seawater and activated carbon powder 92. The second electrode 32 is filled in the entire flow section of the second region 14. The peripheral surface of the second electrode 32 is in close contact with the first filter 41 and the inner surface of the apparatus main body 10.

  The first electrode 31 and the second electrode 32 face each other with the first filter 41 interposed therebetween.

  As shown in FIG. 1, an upper flow path portion 11 a is formed between the upstream end wall of the apparatus main body 10 and the upstream end portions of the electrodes 31, 32 and the first filter 41. The upper flow path portion 11 a is continuous with the supply port 12, spans between the upstream ends of the first region 13 and the second region 14, and communicates with the regions 13 and 14.

The first filter 41 and thus the first and second regions 13 and 14 extend downstream from the first and second electrodes 31 and 32.
A third electrode 33 is disposed in a portion of the first region 13 on the downstream side (the side opposite to the supply port 12) from the first electrode 31. The third electrode 33 is made of, for example, stainless wool and allows permeation of seawater and activated carbon powder 92. The third electrode 33 is filled in the entire flow section of the first region 13. The peripheral surface of the third electrode 33 is in close contact with the first filter 41 and the inner surface of the apparatus main body 10.

  A fourth electrode 34 is disposed in a portion of the second region 14 on the downstream side of the second electrode 32. The fourth electrode 34 is made of, for example, stainless wool and allows permeation of seawater and activated carbon powder 92. The fourth electrode 34 is filled in the entire flow section of the second region 14. The peripheral surface of the fourth electrode 34 is in close contact with the first filter 41 and the inner surface of the apparatus main body 10.

  The third electrode 33 and the fourth electrode 34 are opposed to each other with the first filter 41 interposed therebetween.

  The DC power source 20 includes a battery 21 as a main component. A positive electrode of the DC power supply 20 is connected to the first electrode 31. A negative electrode of the DC power supply 20 is connected to the third electrode 33. The second electrode 32 and the fourth electrode 34 are connected by the short-circuit line 22. When the DC power supply 20 is turned on, the first electrode 31 becomes higher in potential than the second electrode 32. The potential difference between the electrodes 31 and 32 is smaller than the size at which seawater is electrolyzed (about 1 V). The second electrode 32 and the fourth electrode 34 are equipotential.

  The first electrode 31 and the third electrode 33 are sufficiently separated so that the electric field acting between them can be ignored. A first intermediate region 13a (an intermediate portion of the first region 13 of the flow path 11) is formed between the first electrode 31 and the third electrode 33.

  The second electrode 32 and the fourth electrode 34 are separated by substantially the same distance as the first and third electrodes 31 and 33. A second intermediate region 14 a (an intermediate portion of the second region 14 of the flow path 11) is formed between the second electrode 32 and the fourth electrode 34.

  A first take-out port 15 is provided in the longitudinal direction of the apparatus main body 10 and the flow path 11. The take-out port 15 opens so as to continue to the second intermediate region portion 14a. A second filter 42 is provided at the outlet 15. Similar to the first filter 41, the second filter 42 is configured by a filter made of a resin (insulator) such as cellulose or Teflon (registered trademark), and allows permeation of seawater and prevents permeation of activated carbon powder. . The size of the second filter 42 is smaller than the particle size of the activated carbon powder 92, for example, about 10 μm.

  A fresh water supply path 52 extends from the outlet 15. As shown in FIG. 3, the supply path 52 is connected to the supply port 12 of the next-stage desalination apparatus 1.

  As shown in FIG. 1, a lower flow path portion 11 b is formed between the downstream ends of the electrodes 33 and 34 and the first filter 41 and the downstream end wall of the apparatus main body 10. The lower flow path portion 11 b extends between the downstream ends of the first region 13 and the second region 14 and communicates with the regions 13 and 14.

  A second outlet 16 is provided on the downstream end wall of the apparatus body 10. The take-out port 16 opens so as to be continuous with the lower flow path portion 11b. A third filter 43 is provided at the outlet 16. Similar to the first and second filters 41 and 42, the third filter 43 is composed of a filter made of a resin (insulator) such as cellulose or Teflon (registered trademark), and allows permeation of seawater. Blocks the transmission of. The size of the third filter 43 is smaller than the particle size of the activated carbon powder 92, for example, about 10 μm.

  A discharge path 53 is drawn out from the outlet 16.

At the downstream end of the peripheral wall of the apparatus main body 10, an activated carbon recovery port 17 connected to the lower flow path portion 11b is provided. The recovery port 17 can take in the activated carbon powder 92 in the lower flow path portion 11b together with a small amount of seawater. An activated carbon recovery path 54 extends from the recovery port 17. An activated carbon recovery pump 55 such as a screw pump or a tube pump is provided in the recovery path 54. An activated carbon return port 18 is provided at the upstream end of the peripheral wall of the apparatus body 10. A collection path 54 is connected to the activated carbon return port 18. The return port 18 opens to the upper flow path portion 11a.
The activated carbon recovery lines 17, 18, 54, 55 are provided in two sets so as to correspond to the first and second regions 13, 14, respectively, but only one set may be used. The recovery port 17 may be provided on the end wall on the downstream side in the longitudinal direction of the apparatus body 10, and the return port 18 may be provided on the end wall on the upstream side in the longitudinal direction of the apparatus body 10.

A method for desalinating seawater with the desalination system S having the above-described configuration will be described.
A constant amount of seawater is always supplied from the supply port 12 of the first-stage desalination apparatus 1 to the upper flow path portion 11a through the supply path 51. Seawater is mixed with the activated carbon powder 92 in the upper flow path portion 11a. About half of the mixed fluid of seawater and activated carbon powder 92 flows into the first region 13 and enters the first electrode 31 made of stainless wool. The remaining half of the mixed fluid flows into the second region 14 and enters the second electrode 32 made of stainless wool.
Since the electrodes 31 and 32 are filled in the entire flow section of the regions 13 and 14, the mixed fluid can surely enter the electrodes 31 and 32, and does not pass outside the electrodes 31 and 32. Can be. As a result, reaction (Formulas 1-4) mentioned later can be made to occur reliably.

  A potential difference is formed between the first electrode 31 and the second electrode 32 by the DC power supply 20, and the first electrode 31 is at a higher potential than the second electrode 32. The potential difference between the electrodes 31 and 32 is, for example, about 1 V, which is smaller than the seawater electrolysis voltage. Therefore, generation of hydrochloric acid or the like can be prevented.

A positive charge is induced in the first electrode 31, and a negative charge is induced in the second electrode 32. Therefore, when the activated carbon powder 92 in the mixed fluid that has flowed into the first region 13 comes into contact with the stainless wool constituting the first electrode 31, the electrons are deprived (given positive charge) and charged positively (formula 1).
C → C ⁺ + e ⁻ (Formula 1)
Chlorine ions of seawater are adsorbed on the positively charged activated carbon powder 92 (Equation 2). For convenience, the activated carbon powder 92 and chloride ion conjugate is denoted as CCl.
C ^{+ +} Cl ^- → CCl (Equation 2)
Furthermore, due to the electric field between the electrodes 31 and 32, chlorine ions in the upstream side portion of the second region 14 (inside the second electrode 32) pass through the first filter 41, and the upstream side portion of the first region 13 (the first side) 1 electrode 31). Chlorine ions from the second region 14 are also adsorbed to the positively charged activated carbon powder 92 in the first electrode 31 (Formula 2). Since the electrodes 31 and 32 are in close contact with the filter 41, the resistance when chlorine ions in the second region 14 move to the first region 13 can be reduced, and the electric field strength between the electrodes 31 and 32 can be increased. Can also promote the movement of chloride ions.

Further, when the activated carbon powder 92 in the mixed fluid flowing into the second region 14 comes into contact with the stainless wool constituting the second electrode 32, the activated carbon powder 92 receives electrons from the second electrode 32 and is negatively charged (formula 3).
C + e ⁻ → C ⁻ (Formula 3)
The negatively charged activated carbon powder 92 adsorbs sodium ions in seawater (Formula 4). For convenience, the activated carbon powder 92 and sodium ion conjugate are expressed as CNa.
C ⁻ + Na ⁺ → CNa (Formula 4)
Further, due to the electric field between the electrodes 31 and 32, sodium ions in the upstream side portion (inside the first electrode 31) of the first region 13 pass through the first filter 41, and the upstream side portion (second state) of the second region 14. The inside of the two electrodes 32). Sodium ions from the first region 13 are also adsorbed to the negatively charged activated carbon powder 92 in the second electrode 32 (Formula 4). Since the electrodes 31 and 32 are in close contact with the filter 41, the resistance when sodium ions in the first region 13 move to the second region 14 can be reduced, and the electric field strength between the electrodes 31 and 32 can be increased. Can also promote the movement of sodium ions.

  As a result, the concentration of chlorine ions and sodium ions in seawater in the mixed fluid is reduced inside the electrodes 31 and 32. Therefore, seawater is desalinated.

The activated carbon powder 92 in the first electrode 31 cannot pass through the first filter 41 and does not move into the second electrode 32.
The activated carbon powder 92 in the second electrode 32 cannot pass through the first filter 41 and does not move into the first electrode 31.

  The mixed fluid of the desalinated seawater and the activated carbon powder 92 flows from the inside of the electrodes 31 and 32 to the intermediate region portions 13a and 14a. The fresh seawater that has entered the intermediate region 14 a from the second electrode 32 passes through the second filter 42. Fresh seawater that has entered the first intermediate region 13a from the first electrode 31 passes through the first filter 41, and passes through the second filter 42 through the second intermediate region 14a. Thereby, fresh seawater can be taken out from the take-out port 15.

The activated carbon powder 92 that has entered the first intermediate region portion 13 a is blocked by the first filter 41 from entering the second intermediate region portion 14 a, and as a result is prevented from flowing out from the outlet 15.
The activated carbon powder 92 that has entered the second intermediate region portion 14 a is blocked by the first filter 41 from entering the first intermediate region portion 13 a and is blocked by the second filter 42 from flowing out from the take-out port 15.

  The fresh seawater taken out from the take-out port 15 of the first-stage desalination apparatus 1 passes through the supply path 52 extending from the take-out port 15 and enters the apparatus main body 10 from the supply port 12 of the second-stage desalination apparatus 1. be introduced. And it is further desalinated by the same operation as the first stage, and is taken out from the second stage outlet 15. Subsequently, it is introduced into the third-stage desalination apparatus 1 through the take-out port 15 connecting the second and third stages, and further desalinated. In this way, high-quality fresh water can be obtained by sequentially passing seawater through the multi-stage desalination apparatus 1 and promoting desalination for each stage.

The mixed fluid of seawater and activated carbon powder 92 remaining in the first intermediate region 13a enters the inside of the third electrode 33 made of stainless wool. The activated carbon powder 92 in the mixed fluid is positively charged and adsorbs chlorine ions. When the activated carbon powder 92 comes into contact with the stainless wool constituting the third electrode 33, it receives electrons from the third electrode 33 (gives positive charge to the third electrode 33) and becomes electrically neutral. As a result, the chlorine ions are separated from the activated carbon powder 92 and dissolved in seawater (Formula 5).
CCl + e ⁻ → C + Cl ⁻ (Formula 5)
Therefore, a mixed fluid of seawater with a high chlorine ion concentration and electrically neutral activated carbon powder 92 is formed. This mixed fluid flows out from the third electrode 33 to the lower flow path portion 11b.

The mixed fluid of seawater and activated carbon powder 92 remaining in the second intermediate region portion 14a enters the fourth electrode 34 made of stainless wool. The activated carbon powder 92 in the mixed fluid is negatively charged, and sodium ions are adsorbed. When the activated carbon powder 92 comes into contact with the stainless wool constituting the fourth electrode 34, electrons are given to the fourth electrode 34 to become electrically neutral. Thereby, sodium ion leaves | separates from the activated carbon powder 92, and melt | dissolves in seawater (Formula 6).
CNa − e ⁻ → C + Na ⁺ (formula 6)
Therefore, a mixed fluid of seawater having a high sodium ion concentration and electrically neutral activated carbon powder 92 is formed. This mixed fluid flows out from the fourth electrode 34 to the lower flow path portion 11b.

  Since the third and fourth electrodes 31 and 32 are filled in the entire flow sections of the regions 13 and 14, respectively, the mixed fluid can surely enter the electrodes 33 and 34. You can prevent it from passing outside. Therefore, the above reactions (formulas 5 to 6) can be sufficiently caused.

  The third electrode 33 can recover positive charges from the activated carbon powder 92, and the fourth electrode 34 can recover negative charges from the activated carbon powder 92. The positive charge recovered by the third electrode 33 can be used for positive charging of the activated carbon powder 92 at the first electrode 31. The negative charge collected by the fourth electrode 34 can be used for negative charging of the activated carbon powder 92 by the second electrode 32. Therefore, a small amount of current is supplied from the DC power supply 20. Further, since the third electrode 33 receives a positive charge and the fourth electrode 34 receives a negative charge, an electromotive force is generated between the electrodes 33 and 34, and the third electrode 33 becomes higher in potential than the fourth electrode 34. The potential difference between the third electrode 33 and the fourth electrode 34 is slightly smaller than the potential difference between the first electrode 31 and the second electrode 32. For example, when the voltage between the electrodes 31 and 32 is about 1V, the voltage between the electrodes 33 and 34 is about 0.95V. The difference in potential difference corresponds to the voltage of the DC power supply 20. Therefore, the voltage of the DC power supply 20 can be as small as about 0.05V, for example. Thereby, power efficiency can be improved.

  The activated carbon powder 92 in the third electrode 33 cannot pass through the first filter 41 and does not move into the fourth electrode 34. The activated carbon powder 92 in the fourth electrode 34 cannot pass through the first filter 41 and does not move into the third electrode 33. Therefore, it is possible to prevent the positively charged active end powder 92 and the negatively charged activated carbon powder 92 from coming into direct contact. Thereby, the charge recovery efficiency can be increased.

  In the lower flow path portion 11b, the mixed fluid from the third electrode 33 and the mixed fluid from the fourth electrode 34 are mixed. Thereby, a mixed fluid of concentrated seawater with high salinity and activated carbon powder 92 that is electrically neutralized is formed. The concentrated seawater of the mixed fluid passes through the third filter 43. Thereby, the concentrated seawater is taken out from the take-out port 16 and discarded through the discharge path 53.

  The activated carbon powder 92 in the lower flow path portion 11 b cannot pass through the third filter 43. The activated carbon powder 92 is mixed with a small amount of seawater by driving the recovery pump 55, passes through the recovery path 54 through the recovery port 17, and is returned to the upper flow path portion 11 a from the return port 18. As a result, the activated carbon powder 92 can be circulated and reused.

  In the desalination system S, unlike the batch type in which desalination is performed for each certain amount, seawater can be continuously desalted while constantly circulating seawater in the apparatus body 10 of each desalination apparatus 1. Therefore, productivity can be improved.

Next, another embodiment of the present invention will be described. In the following embodiments, the same reference numerals are given to the drawings for the same configurations as those already described, and the description thereof is omitted.
In the embodiment of FIG. 4, the positive electrode of the DC power supply 20 is connected to the fourth electrode 34. A negative electrode of the DC power supply 20 is connected to the second electrode 32. The first electrode 31 and the third electrode 33 are connected by the short-circuit line 22. This embodiment is electrically equivalent to the first embodiment shown in FIG. 1, and a reaction similar to that of the first embodiment occurs at each of the electrodes 31 to 34, and seawater is desalinated.

  In the embodiment of FIG. 5, the first take-out port 15 is provided on the peripheral wall on the first intermediate region portion 13 a side instead of the second intermediate region portion 14 a side of the apparatus body 10, and continues to the first intermediate region portion 13 a. Yes. The fresh seawater that has entered the intermediate region 13 a from the first electrode 31 passes through the second filter 42 and is taken out from the takeout port 15. The fresh seawater that has entered the intermediate region 14 a from the second electrode 32 passes through the first filter 41, passes through the intermediate region 13 a, passes through the second filter 42, and is taken out from the outlet 15.

  In the embodiment of FIG. 6, the first take-out ports 15 are respectively provided on the peripheral wall on the first intermediate region portion 13 a side and the peripheral wall on the second intermediate region portion 14 a side of the apparatus main body 10. A supply path 52 extends from each first outlet 15. The two supply paths 52 and 52 merge with each other. The fresh seawater that has entered the first intermediate region 13a from the first electrode 31 passes through the second filter 42 on the first intermediate region 13a side and is extracted from the outlet 15 on the intermediate region 13a side. The fresh seawater that has entered the second intermediate region portion 14a from the second electrode 32 passes through the second filter 42 on the second intermediate region portion 14a side, and is extracted from the extraction port 15 on the intermediate region portion 14a side. Then, the fresh seawater from the two outlets 15 and 15 are joined together. In this embodiment, even if the part which partitions off the 1st, 2nd intermediate | middle area | region parts 13a and 14a in the 1st filter 41 does not prevent permeation | transmission of activated carbon powder 92 but also permeation | transmission of seawater. Good.

The present invention is not limited to the above embodiment, and various modifications can be made.
For example, as shown in FIG. 7, the positive electrode of the DC power supply 20 is connected to the first electrode 31, the negative electrode of the DC power supply 20 is connected to the second electrode 32, and the third electrode 33 and the fourth electrode 34 are connected to the short-circuit line 22. You may connect with. As a result, current can flow out from the third electrode 33, and current can flow into the fourth electrode 34. In this case, a load may be provided on the wiring 22 and the electromotive force generated between the electrodes 33 and 34 may be consumed by the load.

  The positive electrode of the DC power supply 20 may be connected to the first electrode 31, the negative electrode of the DC power supply 20 may be connected to the second electrode 32, and the electrodes 33 and 34 may be omitted. In this case, the mixed fluid that has flowed into the lower flow path portion 11b via the first area 13 downstream from the intermediate area portion 13a and the mixed fluid that has flowed into the lower flow path portion 11b via the second area 14 downstream from the intermediate area portion 14a. The fluid is mixed, and the positively charged activated carbon powder 92 from the first region 13 and the negatively charged activated carbon powder 92 from the second region 14 are electrically neutralized with each other, and each activated carbon powder 92 is electrically neutralized. Leaves chloride ions or sodium ions.

It is preferable that the electrodes 31 to 34 allow permeation of seawater and the activated carbon powder 92. The electrodes 31 to 34 are not limited to metal wool such as stainless wool, and may be made of wool-like carbon fiber. A plurality of metal plates may be arranged, and seawater and activated carbon powder 92 may flow (permeate) between these metal plates. Each of the electrodes 31 to 34 may be composed of one metal plate. The reactions of the above formulas 1-6 can occur on the surface of the metal plate.
The electrodes 31 to 34 may be separated from the filter 41, and a gap may be formed between the electrodes 31 to 34 and the filter 41. In this case, the filter 41 may be a conductor.
You may make the volume of the apparatus main body 10 small as the desalination apparatus 1 of the back | latter stage of the cascade system S. FIG.

  The present invention is applicable to seawater desalination treatment.

It is a longitudinal cross-sectional view of the seawater desalination apparatus which concerns on 1st Embodiment of this invention. It is a plane sectional view of the above-mentioned seawater desalination apparatus along the II-II line of FIG. 1 is a schematic configuration diagram of a seawater desalination system according to a first embodiment of the present invention. It is a longitudinal cross-sectional view of a part of the seawater desalination apparatus according to the second embodiment of the present invention. It is a longitudinal cross-sectional view of a part of the seawater desalination apparatus according to the third embodiment of the present invention. It is a longitudinal cross-sectional view of a part of the seawater desalination apparatus according to the fourth embodiment of the present invention. It is a longitudinal cross-sectional view which shows the modification of the wiring structure of the seawater desalination apparatus which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS S Seawater desalination system 1 Seawater desalination apparatus 10 Apparatus main body 11 Flow path 11a Upper flow path part 11b Lower flow path part 12 Seawater supply port 13 1st area | region 13a 1st intermediate | middle area part 14 2nd area | region 14a 2nd intermediate | middle area part 15 1st 1 outlet 16 second outlet 17 activated carbon recovery port 18 activated carbon return port 20 DC power source 22 short-circuit wire 31 first electrode 32 second electrode 33 third electrode 34 fourth electrode 41 first filter 42 second filter 43 third filter 51 Seawater supply path 52 Fresh water supply path 53 Discharge path 54 Activated carbon recovery path 55 Activated carbon recovery pump 92 Activated carbon powder

Claims (9)

An apparatus for desalinating seawater,
An apparatus main body having a flow path for mixing and flowing activated carbon powder in seawater;
A first filter which is accommodated in the apparatus main body so as to partition the flow path into first and second regions parallel to each other, and allows permeation of seawater and prevents permeation of activated carbon powder;
A first electrode provided in the first region;
A second electrode provided in the second region so as to face the first electrode across the first filter;
A direct current power source for setting the first electrode to a higher potential than the second electrode in a range where seawater is not electrolyzed;
A first extraction port connected to the flow path downstream from the first electrode and the second electrode;
A second filter that is provided at the first outlet and allows seawater to pass therethrough and prevents activated carbon powder from passing through;
A desalination apparatus comprising: The first outlet is disposed in an intermediate portion of the flow path, and the first filter and thus the first and second regions extend downstream from the intermediate portion of the flow path;
A third electrode provided in a first region downstream of the first outlet,
A fourth electrode provided in a second region downstream of the first extraction port so as to face the third electrode across the first filter;
The desalination apparatus according to claim 1, further comprising: a wiring that causes a current to flow out of the third electrode and a current to flow into the fourth electrode.   The positive electrode of the DC power supply is connected to the first electrode, the negative electrode of the DC power supply is connected to the third electrode, and the second electrode and the fourth electrode are short-circuited, or the DC power supply The positive electrode is connected to the fourth electrode, the negative electrode of the DC power supply is connected to the second electrode, and the first electrode and the third electrode are short-circuited. Desalination equipment. A second extraction port connected to the downstream end of the flow path;
A third filter that is provided at the second outlet and allows seawater to pass therethrough and prevents activated carbon powder from passing through;
A recovery path for returning the activated carbon powder from the downstream end to the upstream end of the flow path;
The desalination apparatus according to claim 1, further comprising:   The desalination apparatus according to any one of claims 2 to 4, wherein each of the first to fourth electrodes allows permeation of seawater and activated carbon powder.   Each of the said 1st-4th electrode is comprised with the metal wool, The desalination apparatus in any one of Claims 2-4 characterized by the above-mentioned.   The desalination apparatus according to claim 5 or 6, wherein the first filter is an insulator, and each of the first to fourth electrodes is in contact with the first filter.   The desalination apparatus according to claim 7, wherein each of the first to fourth electrodes is filled in the entire flow section of the first region or the second region.   A fresh water comprising a plurality of stages of the desalination apparatus according to any one of claims 1 to 8, wherein the first outlet of the front stage desalination apparatus is connected to the upstream end of the flow path of the rear stage desalination apparatus. System.

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