JP2019126764A - Wet exhaust gas desulfurization device and method - Google Patents

Abstract

To provide a wet exhaust gas desulfurization device needing no COD reduction process for drainage.SOLUTION: A wet exhaust gas desulfurization device 101 comprises: a housing 10; an exhaust gas introduction port 11a for introducing the exhaust gas inside the housing 10; a dispersion unit 26 for dispersing an absorbent inside the housing 10; an exhaust gas discharge port 11b for discharging the exhaust gas outside the housing 10; a retention part 13 for retaining the absorbent dispersed by the dispersion unit 26 and composed as a part of the housing 10; and an absorbent discharge port 14 for discharging the absorbent retaining in the retention part 13 outside the housing 10. The wet exhaust gas desulfurization device 101 is configured so that the absorbent dispersed by the unit 26 is capable of contacting with a massive antibacterial metallic member 61 including an antibacterial metal having an antibacterial action against sulfur oxidation bacteria.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a wet exhaust gas desulfurization apparatus and a wet exhaust gas desulfurization method.

  Exhaust gas discharged from a thermal power plant or the like is released into the atmosphere after being desulfurized by an exhaust gas desulfurization apparatus from the viewpoint of suppressing the release of sulfur oxides into the atmosphere. The exhaust gas desulfurization apparatus includes a dry exhaust gas desulfurization apparatus and a wet exhaust gas desulfurization apparatus. Among these, the dry exhaust gas desulfurization apparatus removes the sulfur oxides in the exhaust gas by bringing the exhaust gas into contact with a solid adsorbent such as activated carbon, for example, and adsorbing the sulfur oxides on the solid adsorbent. The wet exhaust gas desulfurization apparatus removes sulfur oxide in exhaust gas by bringing the exhaust gas into contact with an absorption liquid containing an alkali component and absorbing the sulfur oxide in the absorption liquid.

  As a desulfurization method using a wet exhaust gas desulfurization apparatus, a plurality of methods are known depending on the type of absorbing liquid to be used. Specific examples include a lime gypsum method, a caustic soda method, a magnesium method, and the like. For example, limestone (calcium carbonate) is contained in the absorption liquid (slurry) used in the lime gypsum method. When sulfur oxides (such as sulfur dioxide) in the exhaust gas are absorbed by the absorption liquid, sulfite ions are generated in the absorption liquid. And sulfate ion is produced | generated by oxidizing a sulfite ion in an absorption liquid. Sulfate ions react easily with limestone to produce calcium sulfate (gypsum). Thereby, the sulfur content originating in a sulfur oxide can be removed from an absorption liquid as gypsum.

  As a technique related to a wet exhaust gas desulfurization apparatus, a technique described in Patent Document 1 is known. Patent Document 1 describes a wet exhaust gas desulfurization apparatus provided with an absorption tower for absorbing the sulfur oxides contained in the exhaust gas into the absorption liquid by bringing the exhaust gas and the absorption liquid into contact with each other. The wet exhaust gas desulfurization apparatus includes an absorption liquid storage tank for storing an absorption liquid and an absorption liquid ejection part for ejecting the absorption liquid into the inside of the absorption tower, and the ejection liquid is ejected from the absorption liquid ejection part. Then, the absorption liquid that has absorbed the sulfur oxide is stored in the absorption liquid storage tank.

International Publication No. 2017/014200

  By the way, when the present inventors examined, it turned out that COD (chemical oxygen demand) may be high in an absorption liquid (used absorption liquid) which contacted exhaust gas and absorbed sulfur oxide. The reason for this is considered to be that the autotrophic bacteria sulfur oxidizing bacteria (for example, bacteria belonging to the genus Thermithiobacillus) grew in the absorbing solution in which sulfur oxides were absorbed, according to the study of the present inventors. And if sulfur oxidation bacteria proliferate, heterotrophic bacteria (for example, Pseudomonas genus bacteria) which proliferate using the product (organic substance) of sulfur oxidation bacteria may grow. Since organic substances such as saccharides are also produced in the grown heterotrophic bacteria, it is considered that the COD of the used absorbent increases with the production of organic substances by sulfur-oxidizing bacteria.

  If the COD is higher than the drainage standard, the drainage cannot be discharged into a river or the like. Therefore, it is preferable to suppress the increase in COD. Therefore, it is considered effective to suppress the growth of the above-mentioned sulfur-oxidizing bacteria for suppressing the increase in COD. By suppressing the growth of sulfur-oxidizing bacteria, the amount of organic matter produced by sulfur-oxidizing bacteria can be reduced. Moreover, the growth suppression of sulfur oxidizing bacteria also suppresses the growth of heterotrophic bacteria, and the amount of organic substances calculated by the autotrophic bacteria can also be reduced. And as a result, it is thought that the output of organic substance is suppressed and the increase in COD of the used absorbent can be suppressed.

  An object of at least one embodiment of the present invention is to provide a wet exhaust gas desulfurization apparatus and a wet exhaust gas desulfurization method which do not require COD reduction treatment for drainage.

  (1) The wet exhaust gas desulfurization apparatus according to at least some embodiments of the present invention causes sulfur oxide in the exhaust gas to be absorbed in the absorption liquid and removed from the exhaust gas by bringing the exhaust gas and the absorbent into contact with each other. A wet exhaust gas desulfurization device for reducing the exhaust gas, comprising: a casing; an exhaust gas inlet for introducing the exhaust gas into the casing; An exhaust gas discharge port for discharging the exhaust gas to the outside of the housing, and a retention part for retaining the absorption liquid sprayed by the spraying device, and is configured as a part of the housing A retention unit, and an absorption solution outlet for discharging the absorption solution staying in the retention unit to the outside of the casing, and the wet exhaust gas desulfurization device includes the absorption solution dispersed by the dispersion device. And sulfur oxide fine Characterized in that it is contactable to configure the antimicrobial metal member including an antimicrobial metal having antimicrobial activity against.

  According to the configuration of (1) above, the growth of sulfur-oxidizing bacteria can be suppressed by the antibacterial metal member. Thereby, the amount of organic matter produced by sulfur-oxidizing bacteria can be suppressed. In addition, by suppressing the growth of sulfur-oxidizing bacteria, it is possible to suppress the growth of heterotrophic bacteria that grow using the product of sulfur-oxidizing bacteria. Thereby, the output of the organic substance by heterotrophic bacteria can be suppressed. And, from these things, it is possible to suppress the rise of COD of the waste water discharged from the wet waste gas desulfurization device, and it is possible to provide a wet waste gas desulfurization device which does not require COD reduction processing for waste water.

  (2) In some embodiments, in the configuration of the above (1), the spraying device sprays the absorbing liquid discharged to the outside of the housing through the absorbing liquid discharge port into the inside of the housing It is comprised so that it may do.

  According to the configuration of the above (2), it is possible to scatter again the absorbing liquid dispersed inside the casing, absorbing the sulfur oxide and staying in the retention portion. As a result, it is possible to reduce the amount of newly used absorption liquid. Further, even if the absorbent is repeatedly used, COD in the absorbent is maintained at a low level because the growth of sulfur oxidizing bacteria and the like is suppressed as described above. For this reason, the COD reduction process for drainage becomes unnecessary.

  (3) In some embodiments, in the configuration of the above (1) or (2), the antibacterial metal member is disposed at a position where it is immersed in at least a part of the absorbing liquid retained in the retention portion. Features.

  According to the configuration of (3) above, it is possible to suppress the growth of sulfur-oxidizing bacteria and the like in the staying portion, which is an environment in which the absorbing solution containing sulfur oxides stays and sulfur-oxidizing bacteria and the like easily grow.

  (4) In some embodiments, in the configuration of the above (3), the antibacterial metal member includes a massive antibacterial metal member formed in a lump.

  According to the structure of said (4), it is excellent in the handleability of a block antibacterial metal member, and can be made easy to arrange | position to a wet waste gas desulfurization apparatus. In addition, it is possible to promote a certain degree of free movement of the massive antibacterial metal member in the stagnation part by the change of the water pressure accompanying the dispersion of the absorbing liquid by the scattering device. As a result, the antibacterial action of the massive antibacterial metal member can be easily exhibited over a wide area of the retention portion.

  (5) In some embodiments, in the configuration of (4), the wet exhaust gas desulfurization apparatus further includes a mesh member disposed so as to cover the absorption liquid discharge port, and the antibacterial metal member includes the antibacterial metal member, It is configured to be larger than the mesh diameter of the mesh member.

  According to the structure of said (5), it can suppress that an antimicrobial metal member flows out with an absorption liquid through an absorption liquid discharge port. Thereby, the state which the antibacterial metal member was immersed in the absorption liquid can be maintained, and the antibacterial action by the antibacterial metal member can be maintained for a long time.

  (6) In some embodiments, in the configuration of the above (2), the antibacterial metal member is above the liquid level of the absorbing liquid staying in the staying portion and is sprayed by the spraying device. It is arrange | positioned in the position which can contact the said absorption liquid made.

According to the configuration of the above (6), the concentration of the antibacterial metal in the absorbent can be increased, and the growth of sulfur oxidizing bacteria and the like can be suppressed more reliably. That is, the absorbing solution sprayed by the spraying device is an absorbing solution extracted from the retention portion through the absorbing solution discharge port, and has already been in contact with the antibacterial metal member. Therefore, the concentration of the antimicrobial metal in the absorbing liquid can be increased by repeating the contact, the retention, the withdrawal, and the scattering above the retention part.
In addition, since the antibacterial metal member is disposed above the liquid surface, the antibacterial metal member can be easily replaced even when, for example, foreign matter (eg, gypsum) adheres to the surface of the antibacterial metal member. be able to. Furthermore, since the antibacterial metal member can be disposed inside the housing, the wet exhaust gas desulfurization apparatus can be downsized.

  (7) In some embodiments, in the configuration of the above (1) or (2), the wet exhaust gas desulfurization device is configured to circulate the absorbent flowing out of the casing through the absorbent outlet. The antibacterial metal member further includes a circulation system including a pipe line, and an absorption liquid reflux port for returning the absorption liquid flowing through the circulation pipe to the retention portion, and the antibacterial metal member is the absorption liquid flowing through the circulation system. It is arrange | positioned in the position which can contact with.

  According to the configuration of the above (7), it is possible to use again the absorption liquid dispersed inside the housing to absorb the sulfur oxide and stay in the retention part for absorption of the sulfur oxide. As a result, it is possible to reduce the amount of newly used absorption liquid. Further, even if the absorbent is repeatedly used, COD in the absorbent is maintained at a low level because the growth of sulfur oxidizing bacteria and the like is suppressed as described above. For this reason, the COD reduction process for drainage becomes unnecessary. Furthermore, even if foreign matter (for example, gypsum etc.) adheres to the surface of the antibacterial metal member, for example, the antibacterial metal member can be easily replaced outside the housing.

  (8) In some embodiments, in the configuration of the above (7), the circulation system includes at least one antibacterial tank configured to receive the absorption liquid flowing through the circulation line, The antibacterial metal member is disposed inside the at least one antibacterial tank.

  According to said (8), when replacing | exchanging an antibacterial metal member, an antibacterial metal member can be replaced | exchanged without touching an antibacterial metal member by exchanging the whole antibacterial tank, and replacement | exchange work can be performed easily. .

  (9) In some embodiments, in the configuration of the above (1) or (2), at least a part of the inner surface of the staying portion includes the antibacterial metal member.

  According to the configuration of the above (9), it is not necessary to separately add an arrangement process of the antibacterial metal member, and the antibacterial metal member can be arranged at the time of construction of the wet exhaust gas desulfurization apparatus. Thereby, proliferation of sulfur oxidation bacteria etc. can be suppressed, maintaining the number of processes in construction of wet exhaust gas desulfurization equipment.

  (10) In some embodiments, in the configuration of (1) or (2), the wet exhaust gas desulfurization apparatus supplies ions of the antibacterial metal to the absorption liquid sprayed by the spraying apparatus. An antibacterial metal ion supply device is further provided.

  According to the configuration of the above (10), since the ion of the antibacterial metal can be supplied to the absorbing liquid, the diffusion speed of the ion in the absorbing liquid can be improved. Thereby, an antimicrobial action can be exhibited promptly, and an antimicrobial action can be exhibited from the initial stage of operation of a wet exhaust gas desulfurization apparatus. In addition, the concentration of antibacterial metal ions in the absorbent can be easily adjusted.

  (11) In some embodiments, in any one of the configurations (1) to (11), the antibacterial metal contains at least one of nickel and tungsten.

  According to the configuration of the above (11), since the environmental load is small while showing the antibacterial action against sulfur oxidizing bacteria, it is possible to drain to a river or the like without the need to separately provide a process for removing the antibacterial metal member.

  (12) In the wet exhaust gas desulfurization method according to at least some embodiments of the present invention, sulfur oxide in the exhaust gas is absorbed into the absorption liquid and removed from the exhaust gas by bringing the exhaust gas into contact with the absorption liquid. A wet exhaust gas desulfurization method for performing an antibacterial action on the absorbent and the sulfur-oxidizing bacteria sprayed by a spraying device for spraying the absorbent in a casing constituting the wet exhaust gas desulfurization device And contacting with an antimicrobial metal member containing an antimicrobial metal.

  According to the above method (12), the absorbing liquid can contain an antibacterial metal, and the antibacterial metal member can suppress the growth of sulfur-oxidizing bacteria. Thereby, the amount of organic matter produced by sulfur-oxidizing bacteria can be suppressed. In addition, by suppressing the growth of sulfur-oxidizing bacteria, it is possible to suppress the growth of heterotrophic bacteria that grow using the product of sulfur-oxidizing bacteria. Thereby, the output of the organic substance by heterotrophic bacteria can be suppressed. And, from these things, it is possible to suppress the rise of COD of the waste water discharged from the wet waste gas desulfurization apparatus, and it is possible to provide a wet waste gas desulfurization method which does not require COD reduction processing for waste water.

  According to the present invention, it is possible to provide a wet exhaust gas desulfurization device and a wet exhaust gas desulfurization method which do not require COD reduction treatment for waste water.

It is a schematic diagram of the wet exhaust gas desulfurization apparatus which concerns on one Embodiment of this invention. It is a schematic diagram of the wet exhaust gas desulfurization apparatus which concerns on two embodiment of this invention. It is a schematic diagram of the wet exhaust gas desulfurization apparatus which concerns on three embodiment of this invention. It is a schematic diagram of the wet exhaust gas desulfurization apparatus which concerns on four embodiment of this invention. It is a schematic diagram of the wet exhaust gas desulfurization apparatus which concerns on five embodiment of this invention. It is a schematic diagram of the wet exhaust gas desulfurization apparatus which concerns on 6 embodiment of this invention. It is a schematic diagram of the wet exhaust gas desulfurization apparatus which concerns on seven embodiment of this invention. It is a schematic diagram of the wet exhaust gas desulfurization apparatus which concerns on 8 embodiment of this invention. It is a schematic diagram of the wet exhaust gas desulfurization apparatus according to the ninth embodiment of the present invention. It is a schematic diagram of the wet waste gas desulfurization apparatus which concerns on ten embodiment of this invention. It is a schematic diagram of the wet exhaust gas desulfurization apparatus according to the eleventh embodiment of the present invention.

  Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the contents described in the following embodiments or the contents described in the drawings are merely examples, and can be arbitrarily changed and implemented without departing from the gist of the present invention. Moreover, each embodiment can be implemented in any combination of two or more.

  In addition, the dimensions, materials, shapes, relative arrangements, and the like of the components described in the embodiments or shown in the drawings are not intended to limit the scope of the present invention, but are merely illustrative examples. Absent. For simplification of illustration, the relative dimensional ratio may be changed as appropriate.

  For example, a representation representing a relative or absolute arrangement such as “in a direction”, “along a direction”, “parallel”, “orthogonal”, “center”, “concentric” or “coaxial” is strictly Not only does it represent such an arrangement, but also represents a state of relative displacement with an angle or distance that allows the same function to be obtained.

  For example, an expression indicating that things such as “identical”, “equal”, and “homogeneous” are in an equal state not only represents an exactly equal state, but also has a tolerance or a difference that can provide the same function. It also represents the existing state.

  For example, expressions representing shapes such as quadrilateral shapes and cylindrical shapes not only represent shapes such as rectangular shapes and cylindrical shapes in a geometrically strict sense, but also uneven portions and chamfers within the range where the same effect can be obtained. A shape including a part or the like is also expressed.

  On the other hand, the expressions “comprising”, “comprising”, “comprising”, “including”, or “having” one constituent element are not exclusive expressions for excluding the existence of the other constituent elements.

  FIG. 1 is a schematic view of a wet exhaust gas desulfurization apparatus 101 according to an embodiment of the present invention. Hereinafter, the “wet exhaust gas desulfurization apparatus” is simply referred to as “desulfurization apparatus” for the sake of simplicity. The desulfurization apparatus 101 shown in FIG. 1 is configured to cause sulfur oxide (sulfur dioxide, etc.) in exhaust gas to be absorbed by the absorption liquid and removed from the exhaust gas by bringing the exhaust gas generated in a thermal power plant or the like into contact with the absorption liquid. belongs to.

  The absorption liquid used is optional as long as it can absorb sulfur oxides, for example, a slurry (lime gypsum method) in which limestone is dissolved (dispersed), an aqueous solution of sodium hydroxide (sodium hydroxide method), hydroxide hydroxide A slurry (magnesium method) in which magnesium is dissolved (dispersed) can be applied. In this specification, as an example, a slurry in which limestone is dissolved (dispersed) is used. Although the slurry is not strictly a liquid, it is treated as a liquid for convenience in this specification.

  The desulfurization apparatus 101 includes a housing 10, an exhaust gas inlet 11a for introducing exhaust gas into the housing 10, an exhaust gas outlet 11b for discharging exhaust gas to the outside of the housing 10, and a scattering device 26 And a retention portion 13 configured as a part of the housing 10. The absorbing liquid stays in the staying part 13. The stagnant absorption liquid usually contains not only sulfite ions generated by absorbing sulfur oxides in exhaust gas but also sulfate ions generated by oxidation of sulfite ions. Supply of the absorption liquid to the inside of the housing 10 is performed by the pump 21 through an absorption liquid supply system 71 connected to an absorption liquid tank (not shown).

  Further, the desulfurization device 101 includes a spraying device 26 for spraying the absorbing liquid inside the casing 10 and an absorbing liquid discharge port 14 for discharging the absorbing liquid in the staying portion 13 to the outside of the casing 10. . The absorbing liquid is sprayed by the spraying device 26, and the sprayed absorbing liquid and the exhaust gas come into contact with each other in the internal space 15 of the housing 10, whereby the sulfur oxide in the exhaust gas can be absorbed by the absorbing liquid. As a result, sulfur oxides in the exhaust gas are removed, and the sulfur oxide is exhausted to the outside of the desulfurization apparatus 101 as a purified gas which is a purified exhaust gas.

  Further, in the absorbing solution, absorption of sulfur oxides (sulfur dioxide) generates sulfite ions as described above. Then, the sulfite ion is oxidized by air diffusion by the air diffusion pipe 22 (described later) to generate sulfate ion. The generated sulfate ion reacts with calcium carbonate in the absorbing solution to form calcium sulfate (gypsum) and carbon dioxide. The generated carbon dioxide is exhausted to the outside of the desulfurization apparatus 101 together with the purified gas. Further, the produced calcium sulfate is separated and recovered by a solid-liquid separator 43 described later.

  The exhaust gas introduced into the inside of the housing 10 is usually at a high temperature, and the water contained in the absorbing liquid evaporates. Therefore, in order to compensate for the water that has evaporated and decreased, the supply of makeup water through the makeup water nozzle 51 is appropriately performed. The makeup water nozzle 51 is connected by a makeup water supply system 77 to a makeup water tank (not shown). Then, by driving the pump 24 provided in the makeup water supply system 77, the makeup water is supplied via the makeup water nozzle 51.

  Further, the desulfurization apparatus 101 is provided with a diffusion tube 22 for diffusing the oxidation air with respect to the stagnated absorption liquid. The air diffuser 22 is open to the atmosphere via the air supply system 72. Then, the air (oxidation air) in the atmosphere is supplied to the air diffusion pipe 22 through the pump 23 provided in the air supply system 72, and is diffused into the absorbing liquid. Thereby, sulfite ions in the absorbing solution can be oxidized, and sulfate ions can be generated.

  In the desulfurization apparatus 101, the scattering device 26 is configured to disperse the absorbing liquid discharged to the outside of the housing 10 through the absorbing liquid discharge port 14 into the inside of the housing 10. That is, in the desulfurization apparatus 101, the absorbent is repeatedly used. Specifically, the desulfurization apparatus 101 includes a circulation system 73 and a pump 41 for extracting the absorbent from the retention unit 13 through the circulation system 73. Among these, the circulation system 73 includes a circulation pipe 73a through which the absorption liquid discharged to the outside of the casing 10 through the absorption liquid discharge port 14 flows, and an absorption liquid flowing through the circulation pipe 73a inside the casing 10 ( Specifically, it is provided with an absorption liquid recirculation port 73b for returning to the retention part 13). Then, the absorption liquid is circulated between the staying part 13 and the spraying device 26 by driving the pump 41.

  In the desulfurization apparatus 101, the absorption liquid is also circulated in another route. That is, the three-way valve 42 is provided in the circulation system 73, and a part of the absorption liquid flowing in the circulation system 73 is supplied to the solid-liquid separator 43 through the extraction system 74. The solid-liquid separator 43 is, for example, a belt filter (belt press). The absorbing solution supplied to the solid-liquid separator 43 contains calcium sulfate (gypsum) produced as described above. Therefore, calcium sulfate is separated in the solid-liquid separator 43, whereby the sulfur content derived from the sulfur oxides of the exhaust gas stream is removed as a solid content.

  On the other hand, the absorbent after separating calcium sulfate in the solid-liquid separator 43 is drained to the outside through the drainage system 75 and the three-way valve 44. However, part of the absorbent flowing through the drainage system 75 is returned to the inside of the housing 10 through the three-way valve 44 and the return system 76 from the viewpoint of liquid balance.

  As described above, the absorption liquid circulates through the absorption liquid recirculation ports 73b and 73b, so that the absorption liquid dispersed inside the casing 10 and absorbing the sulfur oxide and staying in the retention portion 13 is absorbed. Again, it can be used for the absorption of sulfur oxides. As a result, it is possible to reduce the amount of newly used absorption liquid. Further, even if the absorbent is repeatedly used, COD in the absorbent is maintained at a low level because the growth of sulfur oxidizing bacteria and the like is suppressed as described above. For this reason, the COD reduction process for drainage becomes unnecessary.

  The desulfurization device 101 is configured to be able to contact the absorbing liquid sprayed by the spraying device 26 with an antimicrobial metal member containing an antimicrobial metal having an antimicrobial effect against sulfur-oxidizing bacteria. Specifically, the absorbing liquid sprayed by the spraying device 26 falls by gravity and stays in the staying part 13. Then, in the absorption liquid sprayed by the spraying device 26, that is, the absorption liquid retained in the retention portion 13, a bulk antibacterial metal member 61 (mass The antibacterial metal member is sinking. As a result, the bulk antibacterial metal member 61 is disposed at a position where it is immersed in the absorbing liquid retained in the retention portion 13.

  As described above, it was found by the present inventors that sulfur-oxidizing bacteria and the like easily grow in the inside of the housing 10 (in particular, in the absorbing liquid). And as a result, it turned out that COD of waste_water | drain increases. Therefore, when the massive antibacterial metal member 61 is soaked in the absorbing solution, the absorbing solution containing sulfur oxides is retained, and the growth of sulfur oxidizing bacteria etc. is suppressed in the retention portion 13 which is an environment in which sulfur oxidizing bacteria etc. easily grow. can do. As a result, the increase in the COD of the waste water can be suppressed.

  Note that the bulk antibacterial metal member 61 does not need to be completely immersed in the absorption liquid retained in the retention portion 13, and a part of the bulk antibacterial metal member 61 may be immersed in the absorption liquid.

  Further, by providing the massive antibacterial metal member 61 as the antibacterial metal member, the massive antibacterial metal member 61 can be easily handled and easily disposed in the desulfurization apparatus 101. In addition, the dispersion of the absorbing liquid by the spraying device 26 and the change in the water pressure accompanying the air diffused by the air diffuser 22 can facilitate the movement of the massive antibacterial metal member 61 in the stay part 13 to some extent. As a result, the antibacterial action by the massive antibacterial metal member 61 can be easily exerted over a wide range of the stay part 13.

  The physical properties of the massive antibacterial metal member 61 are not particularly limited as long as they are so-called "bulk". Here, the “lumb shape” refers to a state of being a lump, for example, a lump formed in a shape such as a substantially spherical shape, a substantially cubic shape, a substantially rectangular parallelepiped shape, a substantially weight shape, or a substantially columnar shape. The size of the massive antibacterial metal member 61 is not particularly limited, but the length (particle size) of the longest part is, for example, usually 40 μm or more, preferably 100 μm or more, more preferably 400 μm or more, and the upper limit is usually May be 30 cm or less, preferably 20 cm or less, more preferably 10 cm or less.

  Further, from the viewpoint of suppressing the passage of the bulk antibacterial metal member 61, the mesh diameter (opening) of the filter 62 is preferably smaller than the size (particle diameter) of the bulk antibacterial metal member 61. Therefore, the mesh diameter of the filter 62 may be determined based on the size of the massive antibacterial metal member 61. Specifically, for example, it is usually 40 μm or more, preferably 100 μm or more, more preferably 400 μm or more, and its upper limit. Is usually 25 cm or less, preferably 20 cm or less, more preferably 15 cm or less.

  When the massive antibacterial metal member 61 has a particle diameter of, for example, about several tens of μm to several cm, the massive antibacterial metal member 61 can be said to be macroscopically in a macroscopic manner. However, for example, when observed with a microscope, the massive antibacterial metal member 61 has a certain degree of lumpy state. That is, microscopically, a plurality of antibacterial metal particles (metal particles) are aggregated to form a lump. Therefore, even if it is a macroscopic granular antibacterial metal member, it is referred to as a “bulk antibacterial metal member”.

  Moreover, it is preferable that the surface is rough from the viewpoint of increasing the surface area of the massive antibacterial metal member 61 and enhancing the antibacterial action. Therefore, the bulk antibacterial metal member 61 is preferably manufactured by a manufacturing method that can increase the surface area. Specifically, for example, after preparing a member containing an antibacterial metal, it can be obtained by roughly grinding the prepared member. More specifically, for example, when the antibacterial metal is nickel oxide, for example, nickel (single substance) is put in a container and fired to obtain nickel oxide, and then nickel oxide taken out from the container is crushed. The massive antibacterial metal member 61 can be obtained. However, the nickel oxide taken out from the container can be used as it is without being pulverized.

  Specific types of antibacterial metals contained in the massive antibacterial metal member 61 include nickel, tungsten, silver, copper and the like. The antimicrobial metal may be used alone or in combination of two or more. The antibacterial metal may be a simple substance or a compound such as an oxide, a sulfide, or a complex. When the massive antibacterial metal member 61 is a compound, it may be a compound containing two or more types of antibacterial metals, or a compound containing one or more types of antibacterial metals and a metal other than the antibacterial metals.

  The massive antibacterial metal member 61 preferably contains at least one of nickel and tungsten. By containing at least one metal of nickel and tungsten, it exhibits an antibacterial action against sulfur-oxidizing bacteria, and the environmental load is also small, so it is not necessary to separately provide a process for removing the massive antibacterial metal member 61. It can be drained to etc.

  In addition, when the massive antibacterial metal member 61 comes into contact with the absorbing solution, the antibacterial metal contained in the massive antibacterial metal member 61 is usually eluted in the form of ions (or complex ions). Thereby, an antimicrobial effect is show | played in an absorption liquid. Moreover, when the form of the bulk antibacterial metal member 61 is physically collapsed, the simple substance or compound (or both) of the antibacterial metal is dispersed in the absorption liquid, and thereby the antibacterial action is exhibited in the absorption liquid. is there. Therefore, in the present specification, when “the antibacterial metal is contained in the absorption liquid”, unless otherwise specified, an ion of the antibacterial metal, a simple substance, or a compound (two or more of these) may be the absorption liquid. Is included.

  Further, in the present specification, “the absorption liquid sprayed by the spraying device 26 can be brought into contact with the massive antimicrobial metal member 61 including an antimicrobial metal having an antimicrobial action against sulfur-oxidizing bacteria”, For example, as shown in FIG. 1, the absorbing liquid sprayed by the spraying device 26 and indirect contact with the absorbing liquid staying in the staying portion 13, as shown in FIG. In addition, it is assumed to include direct contact that is sprayed by the spraying device 26 and comes into contact with the absorbing liquid before reaching the staying portion 13.

  A filter 62 disposed so as to cover the absorbent discharge port 14 is provided at the absorbent discharge port 14 which is a connection portion between the retention portion 13 and the circulation system 73. The filter 62 is made of a metal mesh. The massive antibacterial metal member 61 is configured to be larger than the mesh diameter of the filter 62.

  Since the massive antibacterial metal member 61 is larger than the mesh diameter of the filter 62, the massive antibacterial metal member 61 can be prevented from flowing out together with the absorbing liquid through the absorbing liquid discharge port. Thereby, the massive antibacterial metal member 61 can be maintained in the absorbing liquid, and the antibacterial action of the massive antibacterial metal member 61 can be maintained for a long time.

  According to the desulfurization apparatus 101 as described above, the bulk antibacterial metal member 61 can suppress the growth of sulfur oxidizing bacteria. Thereby, the amount of organic matter produced by sulfur-oxidizing bacteria can be suppressed. In addition, by suppressing the growth of sulfur-oxidizing bacteria, it is possible to suppress the growth of heterotrophic bacteria that grow using the product of sulfur-oxidizing bacteria. Thereby, the output of the organic substance by heterotrophic bacteria can be suppressed. And from these, the desulfurization apparatus 101 which can suppress the raise of COD of the waste_water | drain discharged | emitted from a wet exhaust gas desulfurization apparatus, and does not require the COD reduction process for waste_water | drain can be provided.

  Next, a wet exhaust gas desulfurization method in the desulfurization apparatus 101 will be described. In the following description, the “wet exhaust gas desulfurization method” is simply referred to as the “desulfurization method” to simplify the description. A desulfurization method according to an embodiment of the present invention is a method for absorbing sulfur oxides in exhaust gas generated in a thermal power plant or the like into absorption liquid and removing it from exhaust gas by contacting exhaust gas with absorption liquid. It is.

  The desulfurization method according to an embodiment of the present invention is directed to the absorbent and the sulfur-oxidizing bacteria sprayed by the spraying device 26 for spraying the absorbent in the casing 10 constituting the desulfurization device 101. This includes a step of bringing the massive antibacterial metal member 61 having an antibacterial action into contact.

  By going through this process, the absorbing liquid can be made to contain the antibacterial metal, and the massive antibacterial metal member 61 can suppress the growth of sulfur-oxidizing bacteria. Thereby, the amount of organic matter produced by sulfur-oxidizing bacteria can be suppressed. In addition, by suppressing the growth of sulfur-oxidizing bacteria, it is possible to suppress the growth of heterotrophic bacteria that grow using the product of sulfur-oxidizing bacteria. Thereby, the output of the organic substance by heterotrophic bacteria can be suppressed. And from these things, the raise of COD of the waste_water | drain discharged | emitted from a wet exhaust gas desulfurization apparatus can be suppressed, and the desulfurization method which does not require the COD reduction process for waste_water | drain can be provided.

  In the above example, the massive antibacterial metal member 61 is exemplified as the antibacterial metal member, but the antibacterial metal member can have any shape (for example, a plate shape) other than massive.

  FIG. 2 is a schematic diagram of a wet exhaust gas desulfurization apparatus 102 according to two embodiments of the present invention. Hereinafter, the description of the desulfurization apparatus 102 that is common to the desulfurization apparatus 101 will be omitted, and different points will be mainly described.

  In the above desulfurization apparatus 101, the massive antibacterial metal member 61 is provided, but in the desulfurization apparatus 102 shown in FIG. 2, the massive antibacterial metal member 61 is not provided. However, in the desulfurization apparatus 102, the growth of sulfur-oxidizing bacteria in the absorbing solution is suppressed by bringing the corrugated plate 63 carrying the above-mentioned antibacterial metal on the surface into contact with the absorbing solution. Therefore, in the desulfurization apparatus 102, the corrugated sheet 63 carrying the above-mentioned antibacterial metal on the surface corresponds to the antibacterial metal member.

  In the desulfurization apparatus 102, two antibacterial baths 64 and 64 accommodating the corrugated plate 63 are provided. Two antibacterial baths 64, 64 are provided in parallel in the circulation system 73. Therefore, the circulation system 73 is provided with two (at least one may be sufficient) antibacterial baths 64 and 64 configured to receive the absorbent flowing through the circulation pipeline 73a. In the antibacterial tanks 64 and 64, a corrugated plate 63 carrying the antibacterial metal is disposed, and the corrugated plate 63 (antibacterial metal member) is disposed so as to be able to come into contact with an absorbent flowing in the circulation system 73. ing.

  By providing the antibacterial tanks 64 and 64 containing the corrugated sheet 63, the corrugated sheet 63 can be replaced with a new one without touching the corrugated sheet 63 by replacing the entire antibacterial tanks 64 and 64. Work can be done easily.

  In addition, the antibacterial tank 64 through which the absorption liquid flows can be switched by the three-way valves 65 and 65. The two antibacterial tanks 64 and 64 can be removed. By these, while flowing an absorption liquid to one antibacterial tank 64, the other antibacterial tank 64 can be removed and maintenance of the removed antibacterial tank 64 can be performed easily.

  FIG. 3 is a schematic diagram of the wet exhaust gas desulfurization apparatus 103 according to the third embodiment of the present invention. In the desulfurization apparatus 102 shown in FIG. 2 described above, the two antibacterial vessels 64, 64 are provided in the circulation system 73. However, in the desulfurization apparatus 103 shown in FIG. 3, the two antibacterial tanks 64, 64 are provided in the antibacterial tank system 79 independent of the circulation system 73.

  The antibacterial tank system 79 is for extracting the absorption liquid of the retention part 13 and supplying it to the two antibacterial tanks 64, 64, and after bringing the absorption liquid into contact with the corrugated plates 63, 63, it is returned to the retention part 13. is there. Therefore, the absorption liquid circulates between the retention portion 13 and the antibacterial tank 64, 64, and the antibacterial tank system 79 also functions as a circulation system 73. The antibacterial tank system 79 includes the absorption liquid discharge port 14 and the absorption liquid recirculation port 73b, similarly to the circulation system 73 described above. Further, the antibacterial tank system 79 is provided with a pump 78, and the absorption liquid flows through the antibacterial tank system 79 by driving the pump 78.

  The absorption liquid drained from the absorption liquid discharge port 14 to the outside of the housing 10 flows through the antibacterial tank system 79 and is supplied to the antibacterial tanks 64, 64. Then, after the absorption liquid and the corrugated plates 63 and 63 come into contact with each other in the antibacterial tanks 64 and 64, the absorption liquid flows through the antibacterial tank system 79 and is returned to the staying part 13 from the absorption liquid reflux port 73 b. Therefore, the corrugated plates 63, 63 (antibacterial metal members) accommodated in the antibacterial baths 64, 64 are disposed at positions where they can be in contact with the absorbent flowing through the antibacterial bath system 79.

  By arranging the two antibacterial baths 64, 64 in this manner, the antibacterial baths 64, 64 can be easily attached to the existing desulfurization apparatus later. Therefore, even in the existing desulfurization apparatus, the growth of sulfur oxidizing bacteria can be suppressed while maintenance is easily performed.

  FIG. 4 is a schematic diagram of the wet exhaust gas desulfurization apparatus 104 according to the fourth embodiment of the present invention. In the desulfurization apparatus 104 shown in FIG. 4, unlike the above-described desulfurization apparatus 101, the massive antibacterial metal member 61 is not immersed in the absorption liquid of the retention portion 13. Instead, in the desulfurization apparatus 104, the bulk antibacterial metal member 61 is located above the liquid level of the absorption liquid retained in the retention portion 13 and can be in contact with the absorption liquid sprayed by the spraying apparatus 26. Is arranged.

  Specifically, in the desulfurization apparatus 104, a shelf 81 formed of mesh is installed above the spraying apparatus 26 that sprays upward and at a position where the absorbed liquid sprayed reaches. Then, on the upper surface of the shelf 81, a bulk antibacterial metal member 61 is placed. The shelf 81 is supported and fixed inside the housing 10 by a fixing member (not shown). The shelf 81 is made of metal, for example.

  The absorbing solution sprayed upward from the spraying device 26 passes through the bottom surface of the shelf 81 (formed by the mesh as described above) and contacts the bulk antibacterial metal member 61 from below the bulk antibacterial metal member 61. By this contact, the antibacterial metal is contained in the absorption liquid. Then, the absorbing solution that contains the antibacterial metal falls by gravity and stays in the retention portion 13. For this reason, the antibacterial metal is contained in the absorbing liquid staying in the staying portion 13.

  Thus, by arranging the massive antibacterial metal member 61 at the above position, the concentration of the antibacterial metal in the absorbing liquid can be increased, and the proliferation of sulfur-oxidizing bacteria and the like can be more reliably suppressed. That is, the absorbing solution sprayed by the spraying device 26 is an absorbing solution extracted from the retention portion 13 through the absorbing solution discharge port 14 and has already been in contact with the antibacterial metal member. Therefore, the concentration of the antibacterial metal in the absorbing liquid can be increased by repeating the contact, the retention, the extraction, and the scattering above the retention portion 13.

  In addition, since the massive antibacterial metal member 61 is disposed above the liquid surface, even if foreign matter (such as gypsum, for example) adheres to the surface of the massive antibacterial metal member 61, for example, the massive antibacterial effect can be easily achieved. The metal member 61 can be replaced. Furthermore, since the massive antibacterial metal member 61 can be disposed inside the housing 10, the desulfurization apparatus 104 can be downsized.

  Furthermore, since the shelf 81 has rigidity, even if the absorbing liquid is continuously sprayed from the spraying device 26, the shelf 81 is hardly deformed. Therefore, the durability of the shelf 81 can be increased.

  FIG. 5 is a schematic diagram of the wet exhaust gas desulfurization apparatus 105 according to the fifth embodiment of the present invention. In the desulfurization device 104 shown in FIG. 4 described above, the bulk antibacterial metal member 61 is above the liquid level of the absorbing liquid staying in the staying portion 13 and further above the spraying device 26 that sprays upward. Had been placed in. However, in the desulfurization apparatus 105 shown in FIG. 5, the desulfurization apparatus 105 is disposed above the level of the absorption liquid retained in the retention section 13 but below the spraying apparatus 26 that sprays upward. That is, the massive antibacterial metal member 61 is disposed between the liquid surface of the absorbing liquid retained in the retention portion 13 and the spraying device 26 for spraying upward.

  The absorbing liquid sprayed upward by the spraying device 26 falls by gravity when it reaches a certain height. Therefore, the falling absorbing liquid comes in contact with the massive antibacterial metal member 61 disposed below the spraying device 26 from above. By this contact, the antimicrobial metal is contained in the absorbent. Then, the absorbing liquid which contains the antibacterial metal is further dropped by gravity and retained in the retention portion 13. For this reason, an antibacterial metal will be contained in the absorption liquid currently retained by retention part 13.

  Thus, by arranging the massive antibacterial metal member 61 at the above position, the concentration of the antibacterial metal in the absorbing liquid can be increased, and the proliferation of sulfur-oxidizing bacteria and the like can be more reliably suppressed. That is, the absorbing solution sprayed by the spraying device 26 is an absorbing solution extracted from the retention portion 13 through the absorbing solution discharge port 14 and has already been in contact with the antibacterial metal member. Therefore, the concentration of the antibacterial metal in the absorbing liquid can be increased by repeating the contact, the retention, the extraction, and the scattering above the retention portion 13.

  FIG. 6 is a schematic diagram of the wet exhaust gas desulfurization apparatus 106 according to the sixth embodiment of the present invention. In the desulfurization apparatus 104 shown in FIG. 4 described above, the mesh-like shelf 81 is disposed above the spraying apparatus 26, and the massive antibacterial metal member 61 is placed thereon. However, in the desulfurization device 106 shown in FIG. 6, the mesh net 82 is suspended above the spraying device 26, and the massive antibacterial metal member 61 is placed on the net 82. The net 82 is made of metal, for example. Also, the net 82 can be suspended inside the housing 10, for example, by being held (hooked) at any, for example, three or more places on the inner wall of the housing 10.

  The absorbing liquid sprayed upward from the spraying device 26 passes through the mesh net 82 and contacts the bulk antibacterial metal member 61 from below the bulk antibacterial metal member 61. By this contact, the antibacterial metal is contained in the absorption liquid. Then, in the same manner as the desulfurization device 104 shown in FIG. 4 described above, the absorption liquid retained in the retention portion 13 contains an antibacterial metal.

  By placing the massive antibacterial metal member 61 on the net 82, the concentration of the antibacterial metal in the absorbing liquid can be increased as in the case of the desulfurization apparatus 104 shown in FIG. 4 described above. In particular, the net 82 is lightweight and can be easily arranged by being fastened to the inner wall of the housing 10. Therefore, by using the net 82, the massive antibacterial metal member 61 can be easily disposed.

  Further, since the net 82 is flexible, the net 82 can be deformed by the upward dispersion of the absorbing liquid from the distribution device 26. The net 82 can also be deformed by the wind pressure of the exhaust gas. Therefore, the net 82 and the massive antibacterial metal member 61 placed thereon move up and down inside the housing 10. Thereby, even if solid content (calcium carbonate, gypsum, etc.) contained in the absorption liquid adheres to the net 82 and the massive antibacterial metal member 61, the net 82 and the massive antibacterial metal member 61 move up and down appropriately, It is difficult for a minute to stick. As a result, clogging of the mesh constituting the net 82 is suppressed, and the absorbent can be easily brought into contact with the massive antibacterial metal member 61 for a long time. Moreover, since the surface of the massive antibacterial metal member 61 is not easily covered with the solid content and the absorbing liquid easily comes into contact with the surface of the massive antibacterial metal member 61, the antibacterial action can be maintained.

  FIG. 7 is a schematic view of a wet exhaust gas desulfurization apparatus 107 according to the seventh embodiment of the present invention. In the desulfurization apparatus 101 shown in FIG. 1 described above, the massive antibacterial metal member 61 was able to move freely to some extent inside the absorbing liquid. However, in the desulfurization apparatus 107 shown in FIG. 7, the massive antibacterial metal member 61 is accommodated in a mesh-like case 83, and the case 83 containing the massive antibacterial metal member 61 is submerged in the absorbent. The case 83 is made of metal, for example.

  Since the case 83 accommodating the massive antibacterial metal member 61 has a mesh shape, the absorbing liquid flows freely inside and outside the case 83. For this reason, the absorbing liquid can contact the massive antibacterial metal member 61 inside the case 83. Thereby, the growth of sulfur oxidizing bacteria and the like in the absorbing solution can be suppressed. In addition, since the massive antibacterial metal member 61 does not come out of the case 83, the massive antibacterial metal member 61 does not flow out through the absorbent discharge port 14. Thus, the bulk antibacterial metal member 61 can be inserted into the housing 10 without arranging the filter 62 described in FIG. For this reason, the bulk antibacterial metal member 61 can be applied to the existing desulfurization apparatus 107 by retrofitting, and the growth of sulfur oxidizing bacteria and the like can be easily suppressed.

  FIG. 8 is a schematic view of a wet exhaust gas desulfurization apparatus 108 according to an eighth embodiment of the present invention. In the desulfurization apparatuses 101 to 107 shown in FIGS. 1 to 7 described above, a massive antibacterial metal member 61 is used to suppress the growth of sulfur oxidizing bacteria and the like in the absorbing liquid. However, in the desulfurization apparatus 108 shown in FIG. 8, instead of the massive antimicrobial metal member 61, a metal mesh 66 (which may be another structure) configured to include the above-described antimicrobial metal is used. The metal mesh 66 may be composed of an antibacterial metal itself, or the surface of a metal mesh composed of a metal other than the antibacterial metal may be plated with an antibacterial metal or applied with a paint containing the antibacterial metal. It may be given.

  The metal meshes 66 and 66 are immersed in the absorbing liquid in the staying portion 13. Therefore, since the metal meshes 66, 66 are in contact with the absorbing liquid, the metal meshes 66, 66 correspond to the antibacterial metal members. And metal mesh 66, 66 is supported and fixed to case 10 inside absorption liquid. Two metal meshes 66 and 66 are arranged in the desulfurization apparatus 108. Since the metal mesh 66, 66 has a mesh shape as described above, the antibacterial metal eluted from the metal mesh 66, 66 is spread throughout in the absorbing liquid.

  By containing the metal mesh 66 containing an antibacterial metal in the absorbent, it is possible to suppress the growth of sulfur oxidizing bacteria and the like in the absorbent contacting with the metal mesh 66. In particular, since the structure accommodated in the housing 10 may be formed using an antibacterial metal, it is possible to suppress the growth of sulfur-oxidizing bacteria and the like without using a special member.

  FIG. 9 is a schematic diagram of the wet exhaust gas desulfurization apparatus 109 according to the ninth embodiment of the present invention. In each of the desulfurization apparatuses 101 to 108 described above, the antibacterial metal member is provided separately from the casing 10. However, in the desulfurization apparatus 109 shown in FIG. 9, the inner surface of the retention portion 13 constituting a part of the housing 10 is configured to include the antibacterial film 67 as the antibacterial metal material. Note that the antibacterial film 67 may be a part of the inner surface of the stay part 13 instead of the entire inner surface.

  In the dismounting device 109, an antibacterial film 67 containing the above-mentioned antibacterial metal is formed on the inner surface of the retention portion 13. Then, since the antibacterial film 67 contacts the absorbing liquid dispersed and retained by the scattering device 26, the antibacterial film 67 corresponds to the antibacterial metal member. The antibacterial film 67 can be formed by, for example, plating an antibacterial metal on the inner surface of the retention part 13 or applying and drying a paint containing the antibacterial metal on the inner surface of the retention part 13.

  By forming the antibacterial film 67 on the inner surface of the staying portion 13, it is not necessary to add an additional step of arranging the antibacterial metal member, and the antibacterial metal member can be arranged when the desulfurization apparatus 109 is constructed. Thereby, the growth of sulfur oxidizing bacteria and the like can be suppressed while maintaining the number of steps in the installation of the desulfurization apparatus 109.

  FIG. 10 is a schematic diagram of the wet exhaust gas desulfurization apparatus 110 according to the tenth embodiment of the present invention. In each of the desulfurization apparatuses 101 to 109, solid antibacterial metal members are used. Then, when the solid antibacterial metal member and the absorbing liquid come in contact with each other, the absorbing liquid exhibits an antibacterial effect. However, in the desulfurization apparatus 110 shown in FIG. 10, the antibacterial effect | action with an absorption liquid comes to be show | played by inject | pouring an antibacterial metal ion (antibacterial metal ion) directly into an absorption liquid as a liquid antibacterial metal member. ing.

  The desulfurization device 110 includes a pump 91 (antibacterial metal ion supply device) for supplying an antibacterial metal ion-containing aqueous solution containing antibacterial metal ions to the absorbent dispersed by the distribution device 26. The pump 91 is provided in an antibacterial metal ion supply system 90 connected to an antibacterial metal ion-containing aqueous solution tank (not shown). The pump 91 is inverter-controlled, and the injection amount of the antibacterial metal ions can be changed by changing the rotational speed of the inverter (not shown).

  In addition, the desulfurization apparatus 110 is provided with an ion concentration sensor 92 for measuring the concentration of antibacterial metal ions, and a pump 93 for supplying the absorbing solution to the ion concentration sensor 92. As the ion concentration sensor 92, for example, a densitometer based on absorptiometry can be adopted, but it is not limited thereto. The desulfurization device 110 is provided with a calculation control device 94 for adjusting the injection amount of the antibacterial metal ion-containing aqueous solution by the pump 91. Although not shown, the arithmetic and control unit 94 includes a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), an HDD (Hard Disk Drive), a control circuit, and the like. The stored predetermined control program is implemented by the CPU.

  In the desulfurization apparatus 110, the injection of the antibacterial metal ion is performed so that the concentration of the antibacterial metal ion in the absorbing liquid becomes a predetermined set value (which may be a range, hereinafter the same). That is, the drainage from the three-way valve 44 described above reduces the amount of antibacterial metal ions in the absorbent. Therefore, injection of the antibacterial metal ion aqueous solution by the pump 91 is performed so as to compensate for the decrease.

  Specifically, during operation of the desulfurization apparatus 110, the concentration of the antibacterial metal ion in the absorbing liquid is measured using the ion concentration sensor 92. This measured value is input to the arithmetic and control unit 94 through an electric signal line with a broken line in FIG. Then, the arithmetic and control unit 94 controls the rotational speed of the pump 91 and controls the injection amount so that the measured ion concentration becomes a predetermined set value. Thereby, the density | concentration of the antibacterial metal ion in an absorption liquid is maintained by a setting value (it may be near), and proliferation of sulfur oxidation bacteria etc. in an absorption liquid is suppressed.

  As described above, the provision of the pump 91 makes it possible to supply the antibacterial metal ions to the absorbing liquid, so that the diffusion speed of the ions in the absorbing liquid can be improved. Thereby, an antibacterial action can be exhibited rapidly and an antibacterial action can be exhibited from the operation | movement initial stage of the desulfurization apparatus 110. FIG. Further, the concentration of antibacterial metal ions in the absorbing liquid can be easily adjusted.

  FIG. 11 is a schematic view of a wet exhaust gas desulfurization apparatus 111 according to the eleventh embodiment of the present invention. Although not shown, in the desulfurization apparatus 111 shown in FIG. 11 as well, for example, in the same manner as in the embodiments shown in FIGS. In each of the above desulfurizers 101 to 110, the absorbing liquid was sprayed upward from the diffuser 26. However, in the desulfurization device 111 shown in FIG. 11, the absorbing liquid is sprayed downward from the spraying device 26.

  Even if the absorbing liquid is sprayed downward from the spraying device 26, the absorbing liquid can be brought into contact with the exhaust gas to absorb sulfur oxides in the exhaust gas into the absorbing liquid. And since antibacterial metal is contained in the absorption liquid as described above, the growth of sulfur oxides can be suppressed in the absorption liquid.

11a Exhaust gas inlet 11b Exhaust gas outlet 12 Retained liquid 13 Retained portion 14 Absorbed liquid outlet 15 Internal space 22 Aeration pipes 23, 24, 41, 78, 91, 93 Pump 26 Sprinklers 42, 44, 65 Three-way valve 43 Solid liquid Separator 51 Replenishing water nozzle 61 Bulk antibacterial metal member 62 Filter 63 Corrugated plate 64 Antibacterial tank 66 Metal mesh 67 Antibacterial membrane 71 Absorbing liquid replenishment system 72 Air supply system 73 Circulating system 73a Circulating line 73b Absorbing liquid return port 74 Extraction system 75 Drainage system 76 Return system 77 Supply water supply system 79 Antibacterial tank system 81 Shelf 82 Net 83 Case 90 Antibacterial metal ion supply system 91 Pump (Antibacterial metal ion supply device)
92 Ion concentration sensor 94 Arithmetic control devices 101, 102, 103, 104, 105, 106, 107, 108, 109, 110, 111 Desulfurization device (wet exhaust gas desulfurization device)

Claims (12)

A wet exhaust gas desulfurization device for contacting the exhaust gas with the absorbing liquid to absorb the sulfur oxide in the exhaust gas into the absorbing liquid and removing it from the exhaust gas,
And
An exhaust gas inlet for introducing the exhaust gas into the housing;
A spraying device for spraying the absorbent into the housing;
An exhaust gas outlet for discharging the exhaust gas to the outside of the housing;
A retention part for retaining the absorption liquid sprayed by the spraying device, and a retention part configured as a part of the housing;
And an absorption liquid discharge port for discharging the absorption liquid accumulated in the accumulation portion to the outside of the housing;
The wet exhaust gas desulfurization device is configured to be able to contact the absorption liquid sprayed by the spraying device and an antibacterial metal member containing an antibacterial metal having an antibacterial action against sulfur-oxidizing bacteria. Wet exhaust gas desulfurization equipment.   The said spraying device is comprised so that the said absorption liquid discharged | emitted outside the said housing | casing through the said absorption liquid discharge port might be spread | dispersed inside the said housing | casing. Wet exhaust gas desulfurization equipment.   3. The wet exhaust gas desulfurization apparatus according to claim 1, wherein the antibacterial metal member is disposed at a position where the antibacterial metal member is immersed in at least a part of the absorbing liquid staying in the staying portion.   The wet exhaust gas desulfurization apparatus according to claim 3, wherein the antibacterial metal member includes a massive antibacterial metal member formed in a lump. The wet exhaust gas desulfurization apparatus further includes a mesh member arranged to cover the absorption liquid outlet,
The wet exhaust gas desulfurization apparatus according to claim 4, wherein the antibacterial metal member is configured to be larger than the mesh diameter of the mesh member.   The antibacterial metal member is disposed above the liquid surface of the absorbing liquid staying in the staying portion and in a position where it can come into contact with the absorbing liquid sprayed by the spraying device. The wet exhaust gas desulfurization apparatus according to claim 2. The wet exhaust gas desulfurization apparatus is configured to return a circulation pipe through which the absorption liquid discharged to the outside of the housing through the absorption liquid discharge port and the absorption liquid flowing through the circulation pipe to the staying portion. And further comprising a circulation system including an absorption liquid reflux port,
The wet exhaust gas desulfurization apparatus according to claim 1, wherein the antibacterial metal member is disposed at a position where it can be in contact with the absorbent flowing in the circulation system. The circulation system includes at least one antibacterial tank configured to allow the absorption liquid that has flowed through the circulation line to flow in,
The wet exhaust gas desulfurization apparatus according to claim 7, wherein the antibacterial metal member is disposed inside the at least one antibacterial tank.   The wet exhaust gas desulfurization apparatus according to claim 1, wherein at least a part of the inner surface of the retention portion is configured to include the antibacterial metal member.   The said wet exhaust gas desulfurization apparatus was further equipped with the antibacterial metal ion supply apparatus for supplying the ion of the said antibacterial metal to the said absorption liquid spread | dispersed by the said spreading apparatus, It is characterized by the above-mentioned. Wet exhaust gas desulfurization equipment.   The said antibacterial metal contains the metal of at least one of nickel and tungsten, The wet waste gas desulfurization apparatus in any one of Claims 1-10 characterized by the above-mentioned. A wet exhaust gas desulfurization method for removing sulfur oxide in the exhaust gas by absorbing the sulfur oxide in the exhaust gas by contacting the exhaust gas with the absorption liquid;
The absorption liquid sprayed by a spraying device for spraying the absorption liquid into a casing constituting a wet exhaust gas desulfurization device, and an antibacterial metal member containing an antibacterial metal having an antibacterial action against sulfur-oxidizing bacteria A wet exhaust gas desulfurization method comprising a step of contacting.

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