WO2013115108A1 - Oxidation tank, seawater flue-gas desulfurization system and power generation system - Google Patents

Oxidation tank, seawater flue-gas desulfurization system and power generation system Download PDF

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Publication number
WO2013115108A1
WO2013115108A1 PCT/JP2013/051640 JP2013051640W WO2013115108A1 WO 2013115108 A1 WO2013115108 A1 WO 2013115108A1 JP 2013051640 W JP2013051640 W JP 2013051640W WO 2013115108 A1 WO2013115108 A1 WO 2013115108A1
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WIPO (PCT)
Prior art keywords
seawater
sulfur
oxidation tank
flue gas
absorbing
Prior art date
Application number
PCT/JP2013/051640
Other languages
French (fr)
Japanese (ja)
Inventor
貴志 吉元
進 沖野
晴治 香川
裕 中小路
Original Assignee
三菱重工業株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 三菱重工業株式会社 filed Critical 三菱重工業株式会社
Priority to MYPI2014701912A priority Critical patent/MY185282A/en
Priority to CN201390000229.4U priority patent/CN204107298U/en
Publication of WO2013115108A1 publication Critical patent/WO2013115108A1/en

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES 
    • F23J15/00—Arrangements of devices for treating smoke or fumes
    • F23J15/02—Arrangements of devices for treating smoke or fumes of purifiers, e.g. for removing noxious material
    • F23J15/04—Arrangements of devices for treating smoke or fumes of purifiers, e.g. for removing noxious material using washing fluids
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
    • B01D53/34—Chemical or biological purification of waste gases
    • B01D53/46—Removing components of defined structure
    • B01D53/48—Sulfur compounds
    • B01D53/50—Sulfur oxides
    • B01D53/507—Sulfur oxides by treating the gases with other liquids
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2251/00—Reactants
    • B01D2251/10—Oxidants
    • B01D2251/11—Air
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2252/00—Absorbents, i.e. solvents and liquid materials for gas absorption
    • B01D2252/10—Inorganic absorbents
    • B01D2252/103—Water
    • B01D2252/1035—Sea water
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2258/00—Sources of waste gases
    • B01D2258/02—Other waste gases
    • B01D2258/0283—Flue gases
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/72—Treatment of water, waste water, or sewage by oxidation
    • C02F1/74—Treatment of water, waste water, or sewage by oxidation with air
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
    • C02F2103/08—Seawater, e.g. for desalination
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2209/00—Controlling or monitoring parameters in water treatment
    • C02F2209/06—Controlling or monitoring parameters in water treatment pH
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2209/00—Controlling or monitoring parameters in water treatment
    • C02F2209/08—Chemical Oxygen Demand [COD]; Biological Oxygen Demand [BOD]
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES 
    • F23J2215/00—Preventing emissions
    • F23J2215/20—Sulfur; Compounds thereof
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES 
    • F23J2219/00—Treatment devices
    • F23J2219/40—Sorption with wet devices, e.g. scrubbers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES 
    • F23J2900/00—Special arrangements for conducting or purifying combustion fumes; Treatment of fumes or ashes
    • F23J2900/15041—Means for absorbing SOx using seawater

Definitions

  • the present invention relates to an oxidation tank, a seawater flue gas desulfurization system, and a power generation system that oxidizes sulfur-absorbing seawater containing sulfur desulfurized using seawater.
  • exhaust gas combustion exhaust gas
  • SOx sulfur oxide
  • SO 2 sulfur dioxide
  • Seawater flue gas desulfurization equipment supplies seawater and boiler exhaust gas into a desulfurization tower (absorption tower) that has a cylindrical shape or a square shape such as a substantially cylindrical shape placed vertically, and makes the gas-liquid contact with seawater as an absorption liquid. SOx is removed. Seawater after desulfurization (sulfur content-absorbing seawater) used as an absorbent in the desulfurization tower is supplied to the oxidation tank. The sulfur-absorbing seawater flowing in the oxidation tank is diluted with seawater that is not used for desulfurization.
  • a desulfurization tower that has a cylindrical shape or a square shape such as a substantially cylindrical shape placed vertically, and makes the gas-liquid contact with seawater as an absorption liquid. SOx is removed.
  • Seawater after desulfurization (sulfur content-absorbing seawater) used as an absorbent in the desulfurization tower is supplied to the oxidation tank.
  • the sulfur-absorbing seawater flowing in the oxidation tank is diluted with seawater
  • the sulfur-absorbing seawater is oxidized and decarboxylated (aerated) by fine bubbles flowing out from an aeration apparatus (aeration apparatus) installed on the bottom surface of the oxidation tank (see, for example, Patent Document 1).
  • an aeration apparatus as an installed on the bottom surface of the oxidation tank
  • the sulfur-absorbing seawater is discharged after being oxidized with SO 3 and aerated with CO 2 so as to satisfy local environmental standards.
  • An oxidation tank is generally a long water channel (Seawater Oxidation Treatment System: SOTS) with a width of 20 m to 40 m and a length of about 100 m to 200 m, and requires a large installation area.
  • SOTS Seawater Oxidation Treatment System
  • oxygen is supplied in the state of air from the aeration apparatus provided at the bottom of the oxidation tank to almost the entire bottom of the oxidation tank.
  • Conventionally used oxidation tanks supply oxygen in the state of air to sulfur-absorbing seawater flowing through the oxidation tank from the entire bottom surface of the oxidation tank, so the power cost required to operate the oxidation tank is high. .
  • oxygen more than necessary for oxidation of SO 3 in sulfur-absorbing seawater and aeration of CO 2 is supplied, and oxygen is supplied more than necessary, and SO in sulfur-absorbing seawater
  • the oxidation of 3 and the aeration of CO 2 are not performed efficiently.
  • the present invention provides an oxidation tank, a seawater flue gas desulfurization system, and a power generation system that can efficiently process sulfur-absorbing seawater and reduce the total amount of air supplied into the oxidation tank. This is the issue.
  • 1st invention of this invention for solving the subject mentioned above is the dilution which connects with a tank main body, and supplies the seawater for dilution to the sulfur content absorption seawater containing the sulfur content discharged
  • the oxidation tank is characterized in that the amount of air supplied from the means to the sulfur-absorbing seawater is adjusted.
  • the relationship between any one or more of pH, sulfurous acid concentration, alkalinity, and temperature of the sulfur-absorbing seawater and the dissolved oxygen concentration is calculated in advance,
  • the oxidation tank is obtained based on any one or more of pH, sulfurous acid concentration, alkalinity, and temperature of the sulfur-absorbing seawater calculated in advance.
  • the third invention is the oxidation tank according to the first or second invention, wherein the air supply means supplies the air to the sulfur-absorbing seawater at intervals.
  • the air supply means supplies when the dissolved oxygen concentration of the sulfur-absorbing seawater becomes a predetermined value or less. It is a tank.
  • 5th invention is provided in the exhaust gas desulfurization absorption tower which carries out gas-liquid contact of waste gas and seawater, and is provided in the downstream of the said flue gas desulfurization absorption tower, and is any 1st thru
  • a seawater flue gas desulfurization system comprising: a seawater discharge line; and a diluted seawater supply line that supplies the seawater to one or both of the sulfur-absorbing seawater discharge line and the oxidation tank.
  • 6th invention uses the boiler, the exhaust gas discharged
  • a condenser having a desulfurization system for collecting and circulating water condensed by the steam turbine, a flue gas denitration device for denitrating exhaust gas discharged from the boiler, and removing dust in the exhaust gas And a dust collecting device.
  • FIG. 1 is a schematic diagram showing the configuration of a seawater flue gas desulfurization system to which an oxidation tank according to Example 1 of the present invention is applied.
  • FIG. 2 is a diagram showing an example of the relationship between the length of the oxidation tank and the dissolved oxygen concentration in the sulfur-absorbing seawater.
  • FIG. 3 is an explanatory diagram showing an example of the relationship between the length of the oxidation tank and the SO 3 ⁇ concentration and dissolved oxygen concentration dissolved in the sulfur-absorbing seawater.
  • FIG. 4 is an explanatory diagram showing the relationship between the length of the oxidation tank and the air supply amount.
  • FIG. 5 is a schematic diagram illustrating a configuration of a power generation system according to Embodiment 2 of the present invention.
  • FIG. 1 is a schematic diagram showing the configuration of a seawater flue gas desulfurization system to which an oxidation tank according to Example 1 of the present invention is applied.
  • the seawater flue gas desulfurization system 10 includes a flue gas desulfurization absorption tower 11, an oxidation tank 12 according to this embodiment, and a seawater supply line L ⁇ b> 11 that supplies seawater 13 to the flue gas desulfurization absorption tower 11.
  • the seawater 13 is pumped from the sea 21 to the seawater supply line L11 by the pump 22, and a part of the seawater 13 is supplied to the flue gas desulfurization absorption tower 11 via the seawater supply line L12 by the pump 23 or gravity drive as the absorbed seawater 13a. .
  • a part of the remaining seawater 13 is supplied as diluted seawater 13b to the sulfur-absorbing seawater discharge line L13 via the diluted seawater supply line L14, and the remainder of the diluted seawater 13b is supplied as diluted seawater 13c via the diluted seawater supply line L15. It is supplied to the oxidation tank 12.
  • seawater 13 seawater pumped directly from the sea 21 by the pump 22 is used.
  • the present invention is not limited to this, and seawater discharged from a condenser (not shown) is used. May be.
  • the flue gas desulfurization absorption tower 11 is a tower that purifies the exhaust gas 25 by gas-liquid contact between the exhaust gas 25 and the absorbed seawater 13a.
  • the absorbed seawater 13a is ejected in a liquid column shape above the spray nozzle 26, and the exhaust gas 25 and the absorbed seawater 13a supplied via the seawater supply line L12 are brought into gas-liquid contact.
  • the spray nozzle 26 is a spray nozzle that ejects upward in the form of a liquid column, but is not limited thereto, and may be sprayed downward in the form of a shower.
  • the exhaust gas 25 and the absorbed seawater 13a are brought into gas-liquid contact in the flue gas desulfurization absorption tower 11 to cause a reaction represented by the following formula (I), and contained in the form of SO 2 or the like in the exhaust gas 25.
  • the sulfur content such as SOx is absorbed by the absorption seawater 13a, and the sulfur content in the exhaust gas 25 is removed using the absorption seawater 13a.
  • the purified gas 28 desulfurized by the flue gas desulfurization absorption tower 11 is released into the atmosphere through the purified gas discharge passage L16.
  • the diluted seawater supply line L14 is connected to the sulfur content absorption seawater discharge line L13, and the sulfur content absorption seawater 14 in the sulfur content absorption seawater discharge line L13 is mixed with the diluted seawater 13b and diluted.
  • the pH of the sulfur-absorbing seawater 14 in the sulfur-absorbing seawater discharge line L13 can be increased, and re-emission of SO 2 gas can be prevented.
  • SO 2 in the sulfur content absorbed seawater discharge line L13 is dissipated, preventing the leaking to the outside, it can be prevented from emitting a pungent odor.
  • the dilution mixing tank which dilutes and mixes the sulfur content absorption seawater 14 with the dilution seawater 13b in the sulfur content absorption seawater discharge line L13.
  • the sulfur-absorbing seawater 14 is mixed with the diluted seawater 13b in the dilution mixing tank and diluted.
  • the pH of the sulfur-absorbing seawater 14 in the dilution mixing tank can be raised, and re-emission of SO 2 gas can be prevented.
  • SO 2 from being diffused and leaking to the outside in the diluting / mixing tank, it is possible to prevent emitting an irritating odor.
  • the oxidation tank 12 is provided on the downstream side of the flue gas desulfurization absorption tower 11, and is a diluted seawater supply line L15 as dilution seawater supply means, an aeration device (aeration apparatus) 31 as air supply means, and a dissolved oxygen concentration measurement device. 32.
  • the diluted seawater supply line L15 is provided and the diluted seawater 13c is supplied to the oxidation tank 12.
  • the present invention is not limited to this, and the diluted seawater supply line L15 is not provided. Also good.
  • the diluted seawater supply line L15 connects the diluted seawater supply line L14 and the oxidation tank 12, and supplies the diluted seawater 13c to the sulfur-absorbing seawater 14 in the oxidation tank 12.
  • the aeration apparatus 31 is provided in the oxidation tank 12 and supplies air 33 to the sulfur-absorbing seawater 14.
  • the aeration apparatus 31 includes an oxidation air blower 34 that supplies air 33, an air diffuser 35 that supplies air 33, and an oxidation that supplies air 33 to the sulfur-absorbing seawater 14 in the oxidation tank 12. And an air nozzle 36.
  • the external air 33 is sent from the oxidizing air nozzle 36 into the oxidation tank 12 through the air diffuser 35 by the oxidizing air blower 34, and oxygen is dissolved as shown in the following formula (II).
  • the sulfur content in the sulfur-absorbing seawater 14 comes into contact with the air 33, and an oxidation reaction of bisulfite ions (HSO 3 ⁇ ) such as the following formulas (III) to (V) and bicarbonate ions (HCO 3 - produce and decarboxylation), sulfur absorbing seawater 14 is water recovered, the water recovery seawater 37.
  • the number of the oxidizing air nozzles 36 is not particularly limited, and is appropriately provided according to the size of the inside of the oxidation tank 12.
  • the pH of the sulfur-absorbing seawater 14 can be raised and the chemical oxygen demand (COD) can be reduced, and the pH, dissolved oxygen concentration, and COD of the water-recovered seawater 37 can be discharged into the seawater. Can be released as any level.
  • the generated gas can be diffused in the oxidation tank 12 so as to satisfy the SO 2 environmental standard concentration.
  • the water quality recovery seawater 37 is discharged into the sea 21 through the seawater discharge line L17.
  • a dissolved oxygen concentration measuring device 32 is provided in the oxidation tank 12 to measure the dissolved oxygen concentration in the sulfur-absorbing seawater 14.
  • a plurality of dissolved oxygen concentration measuring devices 32 are provided in the flow direction of the sulfur-absorbing seawater 14 in the oxidation tank 12. Examples of the dissolved oxygen concentration measuring device 32 include commercially available portable oxygen and stationary oxygen meters. The measurement result measured by the dissolved oxygen concentration measuring device 32 is transmitted to the control device 38.
  • the dissolved oxygen concentration can be determined based on any one or more of pH, sulfurous acid concentration, alkalinity, and temperature of the sulfur-absorbing seawater 14.
  • the relationship between any one or more of the pH, sulfurous acid concentration, alkalinity, and temperature of the sulfur-absorbing seawater 14 and the dissolved oxygen concentration is calculated in advance, and the controller 38 calculates the pH of the sulfur-absorbing seawater 14 calculated in advance.
  • the controller 38 calculates the pH of the sulfur-absorbing seawater 14 calculated in advance.
  • the controller 38 calculates the pH of the sulfur-absorbing seawater 14 calculated in advance.
  • the controller 38 calculates the pH of the sulfur-absorbing seawater 14 calculated in advance.
  • the controller 38 calculates the pH of the sulfur-absorbing seawater 14 calculated in advance.
  • the controller 38 calculates the pH of the sulfur-absorbing seawater 14 calculated in advance.
  • the controller 38 calculates the pH of the sulfur-absorbing seawater 14 calculated in advance.
  • control device 38 determines the sulfur from each oxidized air nozzle 36 of the aeration device 31 based on the relationship between the length of the oxidation tank 12 and the dissolved oxygen concentration in the sulfur-absorbing seawater 14 determined in advance. The amount of air 33 supplied to the partial absorption seawater 14 is adjusted.
  • FIG. 2 An example of the relationship between the length of the oxidation tank 12 and the dissolved oxygen concentration in the sulfur-absorbing seawater 14 is shown in FIG. As shown in FIG. 2, the relationship between the length of the oxidation tank 12 and the dissolved oxygen concentration in the sulfur-absorbing seawater 14 is used to determine the air 33 supplied to the sulfur-absorbing seawater 14 from each aeration device 31. The amount of air can be adjusted.
  • the aeration apparatus 31 supplies the air 33 to the sulfur-absorbing seawater 14 with an interval.
  • the supply with a gap means a meaning other than the case where the air 33 is constantly supplied from all the oxidized air nozzles 36 to the sulfur-absorbing seawater 14. This means that the air 33 is supplied to the sulfur-absorbing seawater 14 from the limited oxidizing air nozzle 36 while being maintained.
  • the aeration apparatus 31 is preferably supplied when the dissolved oxygen concentration of the sulfur-absorbing seawater 14 becomes a predetermined value or less.
  • the predetermined value refers to an amount that can secure a sufficient oxidation rate. This predetermined value is not limited to the case where the dissolved oxygen concentration is 1/3 of the saturated concentration.
  • the aeration apparatus 31 When supplying the air 33 to the sulfur-absorbing seawater 14, the aeration apparatus 31 supplies a large amount of air 33 to the upstream side of the oxidation tank 12 and reduces the supply amount of the air 33 as it goes downstream of the oxidation tank 12. It is preferable to do this. This is because the air 33 supplied to the oxidation tank 12 is not immediately consumed by the oxidation of sulfite ions (SO 3 ⁇ ) dissolved in the sulfur-absorbing seawater 14 or CO 2 aeration. It flows downstream of the oxidation tank 12. Further, since the concentration of SO 3 ⁇ is high on the upstream side of the oxidation tank 12 and the oxidation easily proceeds, the dissolved oxygen in the sulfur-absorbing seawater 14 tends to decrease.
  • SO 3 ⁇ sulfite ions
  • FIG. 3 is an explanatory diagram showing an example of the relationship between the length of the oxidation tank 12 and the SO 3 ⁇ concentration and dissolved oxygen concentration dissolved in the sulfur-absorbing seawater 14.
  • the air 33 is supplied to the oxidant tank 12 at intervals, and the supply amount is adjusted so that the SO 3 ⁇ concentration in the sulfur-absorbing seawater 14 is constantly supplied to the oxidizer 12. Can be reduced to almost the same.
  • the length of the oxidation tank 12 is approximately equal to the length of the oxidation tank 12 required to regenerate and release the sulfur-absorbing seawater 14 by constantly supplying air 33 into the oxidation tank 12 as in the prior art. Can be adjusted.
  • FIG. 4 is an explanatory diagram showing the relationship between the length of the oxidation tank 12 and the air supply amount.
  • the length of the oxidation tank 12 in the longitudinal direction is set to 1.0, and the oxidation tank 12 when the air 33 is uniformly supplied to each of the regions equally divided into five in the length direction of the oxidation tank 12.
  • the ratio of the total air supplied to the inside is set to 1.0 (see Comparative Example 1).
  • the length of each region when the oxidation tank 12 is divided into five is changed, and the amount of air supplied to each region is adjusted.
  • the length of the region where the air 33 is supplied to the oxidation tank 12 is lengthened, the length of the region where the air 33 is not supplied is shortened, and the amount of air supplied into the oxidation tank 12 is It is adjusted so that it increases toward the downstream side of the oxidation tank 12 and decreases toward the downstream side of the oxidation tank 12.
  • the total amount of air supplied to the oxidation tank 12 is reduced by, for example, about 20%, compared to the case where the air 33 is constantly and uniformly supplied to each region in the oxidation tank 12 as in Comparative Example 1.
  • each relationship of the aeration apparatus 31 is shown using the relationship figure which shows the relationship between the length of the oxidation tank 12 calculated
  • FIG. The amount of air 33 supplied to the sulfur-absorbing seawater 14 from the oxidized air nozzle 36 is adjusted, and the length of each region when the oxidation tank 12 is divided into a plurality of regions and the amount of air supplied to each region are adjusted. Yes. Therefore, the oxidation tank 12 which concerns on a present Example reduces the number of the aeration apparatus 31 installed in the oxidation tank 12 by enlarging the oxidation tank 12 by processing the sulfur content absorption seawater 14 efficiently. In addition, it is possible to reduce the total air amount of the air 33 supplied from the aeration device 31 into the oxidation tank 12 and reduce the power required to supply the air 33.
  • the seawater flue gas desulfurization system 10 to which the oxidation tank 12 according to the present embodiment is applied can reduce the number of oxidized air nozzles 36 of the aeration apparatus 31 installed in the oxidation tank 12 and also the oxidation tank 12. Since the total amount of air supplied into the interior can be reduced and the power required to supply the air 33 can be reduced, the sulfur-absorbing seawater 14 that has flowed into the outer open type oxidation tank 12 is efficiently oxidized, Water quality recovery treatment can be performed.
  • the sulfur-absorbing seawater 14 discharged from the flue gas desulfurization absorption tower 11 is converted into the oxidized air of the aeration apparatus 31 in the oxidation tank 12. Since the air 33 is efficiently supplied into the oxidation tank 12 while reducing the number of nozzles 36, the sulfur-absorbing seawater 14 can be efficiently processed and the water quality recovery process can be performed.
  • a flue gas desulfurization system can be provided.
  • seawater flue gas desulfurization system for treating the absorbed seawater 13a used for the seawater desulfurization in the flue gas desulfurization absorption tower 11 has been described, but the present invention is not limited to this.
  • Seawater flue gas desulfurization system is included in exhaust gas discharged from, for example, factories in various industries, power plants such as large and medium-sized thermal power plants, large boilers for electric utilities or general industrial boilers, steelworks, smelters, etc.
  • the present invention can also be applied to a seawater flue gas desulfurization apparatus that desulfurizes the generated sulfur oxides.
  • the flue gas desulfurization absorption tower 11 and the oxidation tank 12 are independent as separate tanks, and the flue gas desulfurization absorption tower 11 and the oxidation tank 12 are connected by a sulfur content absorption seawater discharge line L13.
  • the present embodiment is not limited to this, and the flue gas desulfurization absorption tower 11 and the oxidation tank 12 may be integrated into a single tank.
  • a power generation system according to Example 2 of the present invention will be described with reference to the drawings.
  • the seawater flue gas desulfurization system according to the first embodiment is used for the seawater flue gas desulfurization system applied to the power generation system according to the present embodiment.
  • symbol is attached
  • FIG. 5 is a schematic diagram illustrating a configuration of a power generation system according to Embodiment 2 of the present invention.
  • a power generation system 40 according to this embodiment includes a boiler 41, a steam turbine 42, a condenser 43, a flue gas denitration device 44, a dust collector 45, and a seawater flue gas desulfurization system. 10.
  • the sulfur-absorbing seawater 14 is used seawater that has absorbed sulfur such as SO 2 in the seawater flue gas desulfurization system 10.
  • the boiler 41 injects and burns fuel 46 supplied from an oil tank or a coal mill from a burner (not shown) together with air 48 preheated by an air preheater (AH) 47.
  • the air 48 supplied from the outside is supplied to the air preheater 47 by the pushing fan 49 and preheated.
  • the fuel 46 and the air 48 preheated by the air preheater 47 are supplied to a burner (not shown), and the fuel 46 is combusted by the boiler 41. Thereby, the steam 50 for driving the steam turbine 42 is generated.
  • the exhaust gas 51 generated by combustion in the boiler 41 is sent to the flue gas denitration device 44. Further, the exhaust gas 51 is used as a heat source for exchanging heat with water 52 discharged from the condenser 43 and generating steam 50.
  • the steam turbine 42 drives the generator 53 using the generated steam 50.
  • the condenser 43 collects the water 52 condensed by the steam turbine 42 and returns it to the boiler 41 for circulation.
  • the exhaust gas 51 discharged from the boiler 41 is denitrated in the flue gas denitration device 44, exchanged heat with the air 48 by the air preheater 47, and then sent to the dust collector 45 to remove the dust in the exhaust gas 51.
  • the exhaust gas 51 removed by the dust collector 45 is supplied into the flue gas desulfurization absorption tower 11 by the induction fan 55.
  • the exhaust gas 51 is heat-exchanged by the heat exchanger 56 with the purified gas 28 desulfurized and discharged by the flue gas desulfurization absorption tower 11, and then supplied into the flue gas desulfurization absorption tower 11.
  • the exhaust gas 51 may be directly supplied to the flue gas desulfurization absorption tower 11 without exchanging heat with the purified gas 28 by the heat exchanger 56.
  • the heat exchanger 56 includes a heat recovery device and a reheater, and a heat medium circulates between the heat recovery device and the reheater.
  • the heat recovery unit is provided between the induction fan 55 and the flue gas desulfurization absorption tower 11 and exchanges heat between the exhaust gas 51 discharged from the boiler 41 and the heat medium.
  • the reheater is provided on the downstream side of the flue gas desulfurization absorption tower 11, exchanges heat between the purified gas discharged from the flue gas desulfurization absorption tower 11 and the heat medium, and reheats the purified gas. To do.
  • the seawater flue gas desulfurization system 10 is the seawater flue gas desulfurization apparatus according to Example 1 described above. That is, the seawater flue gas desulfurization system 10 includes a flue gas desulfurization absorption tower 11, an oxidation tank 12, seawater supply lines L11 and L12, a sulfur content absorption seawater discharge line L13, and diluted seawater supply lines L14 and L15. It is what you have.
  • the seawater desulfurization is performed using the seawater 13 pumped up from the sea 21 by sulfur contained in the exhaust gas 51.
  • the seawater 13 is pumped from the sea 21 by the pump 22, and after heat exchange is performed by the condenser 43, a part of the absorbed seawater 13 a is supplied to the seawater flue gas desulfurization system 10 by the pump 23 via the seawater supply line L 12. Is done.
  • the remaining diluted seawater 13b is fed to the upstream side of the oxidation tank 12 through the diluted seawater supply line L14.
  • the exhaust gas 51 and the absorbed seawater 13a are brought into gas-liquid contact, and the sulfur content in the exhaust gas 51 is absorbed by the absorbed seawater 13a.
  • the sulfur-absorbing seawater 14 that has absorbed the sulfur is discharged from the flue gas desulfurization absorption tower 11, mixed with diluted seawater 13 b, diluted, and fed upstream of the oxidation tank 12. Further, the exhaust gas 51 purified by the seawater flue gas desulfurization system 10 becomes the purified gas 28 and is discharged outside from the chimney 57 through the purified gas discharge passage L16.
  • the electric power generation system 40 which concerns on a present Example supplies a part of dilution seawater 13b to the upstream in the oxidation tank 12 via the dilution seawater supply line L15, it is not limited to this, Dilution A part of the seawater 13b may not be supplied to the upstream side in the oxidation tank 12 via the diluted seawater supply line L15.
  • the seawater 13 pumped from the sea 21 is heat-exchanged by the condenser 43 and then sent to the seawater flue gas desulfurization system 10 for use in seawater desulfurization.
  • the seawater 13 pumped from the sea 21 is condensed into water. Instead of heat exchange in the vessel 43, it may be directly fed to the seawater flue gas desulfurization system 10 and used for seawater desulfurization.
  • the oxidation tank 12 After the sulfur-absorbing seawater 14 is mixed with the diluted seawater 13b in the dilution mixing tank, it is fed to the oxidation tank 12.
  • the oxidation tank 12 has a diluted seawater supply line L15, an aeration device 31, and a dissolved oxygen concentration measurement device 32.
  • the control device 38 determines each aeration device 31 based on the relationship between the length of the oxidation tank 12 and the dissolved oxygen concentration in the sulfur-absorbing seawater 14 obtained in advance. The amount of air 33 supplied to the sulfur-absorbing seawater 14 from the oxidized air nozzle 36 is adjusted.
  • the sulfur-absorbing seawater 14 is efficiently processed, and the oxidation tank 12 is not enlarged.
  • the number of aeration devices 31 installed in the tank 12 can be reduced, and the power required to supply the air 33 by reducing the total amount of air 33 supplied from the aeration device 31 into the oxidation tank 12. Can be reduced.
  • the water quality recovery seawater 37 obtained in the oxidation tank 12 is discharged from the oxidation tank 12 to the sea 21 via the seawater discharge line L17 with pH, dissolved oxygen concentration, and COD at a level at which seawater can be discharged.
  • the electric power generation system 40 which concerns on a present Example is equipped with the diluted seawater supply line L18 which supplies a part of seawater 13 from the seawater supply line L11 to the downstream of the oxidation tank 12 other than the absorption seawater 13a and the diluted seawater 13b. Yes.
  • the power generation system 40 according to the present embodiment supplies a part of the seawater 13 from the seawater supply line L11 to the downstream side of the water quality recovery seawater 37 in the oxidation tank 12 via the diluted seawater supply line L18. Thereby, the water quality recovery seawater 37 can be further diluted.
  • the pH of the water quality recovery seawater 37 is increased, the pH of the seawater drainage is increased until it approaches the pH of the seawater 21, and the drainage standard (pH 6.0 or higher) of the pH of the seawater drainage is satisfied.
  • the pH and COD of the water quality recovery seawater 37 can be released as a level at which seawater can be discharged.
  • the water is supplied to the downstream side in the oxidation tank 12 via the diluted seawater supply line L18.
  • the present invention is not limited to this, and a part of the diluted seawater 13b is supplied to the diluted seawater supply line. It is not necessary to supply to the downstream side in the oxidation tank 12 via L18.
  • the air 33 is efficiently supplied into the oxidation tank 12 while reducing the number of aeration devices 31 installed in the oxidation tank 12.
  • the sulfur-absorbing seawater 14 can be efficiently processed and the total amount of air supplied into the oxidation tank 12 can be reduced. Therefore, the power for supplying the air 33 to the sulfur-absorbing seawater 14 in the oxidation tank 12 This can reduce the running cost. Therefore, since the power generation system 40 according to the present embodiment can efficiently and stably process the sulfur-absorbing seawater 14 and perform water quality recovery processing, it is possible to provide a power generation system with high safety and reliability. it can.
  • seawater flue gas desulfurization system 10 is, for example, in exhaust gas discharged from factories in various industries, power plants such as large-sized and medium-sized thermal power plants, large boilers for electric utilities, or general industrial boilers. Can be used for removal of sulfur content in the sulfur content absorption solution produced by desulfurizing seawater.

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Abstract

This oxidation tank (12) is characterized by comprising: a diluted seawater supply line (L14) which is coupled to a tank body in order to supply diluted seawater (13b) for dilution to sulfur content-absorbed seawater (14) containing sulfur content and discharged from a flue-gas desulfurization absorption tower (11); an aeration device (31) which is provided in the tank body and supplies air (33) to the sulfur content-absorbed seawater (14) discharged from the flue-gas desulfurization absorption tower (11); and a dissolved oxygen concentration measurement device (32) which is provided in the tank body and measures the dissolved oxygen concentration in the sulfur content-absorbed seawater (14), and adjusting the air quantity to be supplied from the aeration device (31) to the sulfur content-absorbed seawater (14) on the basis of the relation between the previously acquired length of the oxidation tank (12) and the dissolved oxygen concentration in the sulfur content-absorbed seawater (14).

Description

酸化槽、海水排煙脱硫システムおよび発電システムOxidation tank, seawater flue gas desulfurization system and power generation system
　本発明は、海水を用いて脱硫した硫黄分を含んだ硫黄分吸収海水を酸化処理する酸化槽、海水排煙脱硫システムおよび発電システムに関する。 The present invention relates to an oxidation tank, a seawater flue gas desulfurization system, and a power generation system that oxidizes sulfur-absorbing seawater containing sulfur desulfurized using seawater.
　石炭や原油等を燃料とする発電プラントにおいて、石炭等の化石燃料を燃焼することでボイラから排出される燃焼排気ガス（以下、「排ガス」という）には硫黄酸化物（ＳＯｘ）など硫黄分が含まれる。そのため、排ガスは、脱硫処理され、排ガス中に含まれている二酸化硫黄（ＳＯ2）等の硫黄酸化物（ＳＯｘ）を除去してから大気に放出される。このような脱硫処理方法として、石灰石膏法、スプレードライヤー法および海水法等がある。 In power plants that use coal or crude oil as fuel, combustion exhaust gas (hereinafter referred to as “exhaust gas”) discharged from boilers by burning fossil fuels such as coal contains sulfur components such as sulfur oxide (SOx). included. Therefore, the exhaust gas is desulfurized and released to the atmosphere after removing sulfur oxides (SOx) such as sulfur dioxide (SO 2 ) contained in the exhaust gas. Examples of such a desulfurization method include a lime gypsum method, a spray dryer method, and a seawater method.
　発電所などは大量の冷却水を必要とするため海に面した場所に建設される場合が多い。そのため、脱硫処理に要する稼動コストを抑えることなどの観点から、海水を排ガス中の硫黄酸化物を吸収する吸収液として利用して脱硫を行う海水脱硫を用いた海水排煙脱硫装置が提案されている。 発 電 Power plants are often constructed in locations facing the sea because they require a large amount of cooling water. For this reason, a seawater flue gas desulfurization apparatus using seawater desulfurization that performs desulfurization using seawater as an absorbing liquid that absorbs sulfur oxide in exhaust gas has been proposed from the viewpoint of suppressing the operating cost required for the desulfurization treatment. Yes.
　海水排煙脱硫装置は、略円筒のような筒形状または角形状を縦置きにした脱硫塔（吸収塔）の内部に海水およびボイラ排ガスを供給し、海水を吸収液として気液接触させることでＳＯｘを除去している。脱硫塔内で吸収剤として使用した脱硫後の海水（硫黄分吸収海水）は、酸化槽に供給される。酸化槽内を流れる硫黄分吸収海水は脱硫に用いていない海水と混合して希釈される。また、硫黄分吸収海水は、酸化槽の底面に設置した曝気装置（エアレーション装置）から流出される微細気泡によって酸化・脱炭酸（曝気）される（例えば、特許文献１参照）。これにより、硫黄分吸収海水は、ＳＯ3の酸化とＣＯ2の曝気処理がされて、地域の環境基準を満足するようにした後に放流される。 Seawater flue gas desulfurization equipment supplies seawater and boiler exhaust gas into a desulfurization tower (absorption tower) that has a cylindrical shape or a square shape such as a substantially cylindrical shape placed vertically, and makes the gas-liquid contact with seawater as an absorption liquid. SOx is removed. Seawater after desulfurization (sulfur content-absorbing seawater) used as an absorbent in the desulfurization tower is supplied to the oxidation tank. The sulfur-absorbing seawater flowing in the oxidation tank is diluted with seawater that is not used for desulfurization. In addition, the sulfur-absorbing seawater is oxidized and decarboxylated (aerated) by fine bubbles flowing out from an aeration apparatus (aeration apparatus) installed on the bottom surface of the oxidation tank (see, for example, Patent Document 1). As a result, the sulfur-absorbing seawater is discharged after being oxidized with SO 3 and aerated with CO 2 so as to satisfy local environmental standards.
特開２００７－１２５４７４号公報JP 2007-125474 A
　酸化槽は、一般に、幅２０ｍ～４０ｍ、長さ１００ｍ～２００ｍ程度の上部が開放された長い水路（Seawater　Oxidation　Treatment　System；ＳＯＴＳ）であり、広い設置面積が必要である。酸化槽では、酸化槽の底部に設けたエアレーション装置から酸化槽の底部のほぼ全面に空気の状態で酸素を供給するようにしている。 An oxidation tank is generally a long water channel (Seawater Oxidation Treatment System: SOTS) with a width of 20 m to 40 m and a length of about 100 m to 200 m, and requires a large installation area. In the oxidation tank, oxygen is supplied in the state of air from the aeration apparatus provided at the bottom of the oxidation tank to almost the entire bottom of the oxidation tank.
　従来から用いられている酸化槽は、酸化槽の底部全面から酸化槽内を流れる硫黄分吸収海水に空気の状態で酸素を供給するようにしているため、酸化槽の運転に要する動力コストが高い。また、硫黄分吸収海水中のＳＯ3の酸化とＣＯ2の曝気に必要な酸素以上の酸素を供給している場所もあり、酸素を必要以上に供給しており、硫黄分吸収海水中のＳＯ3の酸化とＣＯ2の曝気が効率的に行われていない。 Conventionally used oxidation tanks supply oxygen in the state of air to sulfur-absorbing seawater flowing through the oxidation tank from the entire bottom surface of the oxidation tank, so the power cost required to operate the oxidation tank is high. . In addition, there is a place where oxygen more than necessary for oxidation of SO 3 in sulfur-absorbing seawater and aeration of CO 2 is supplied, and oxygen is supplied more than necessary, and SO in sulfur-absorbing seawater The oxidation of 3 and the aeration of CO 2 are not performed efficiently.
　本発明は、前記課題に鑑み、硫黄分吸収海水の処理を効率良く行い、酸化槽内に供給される総空気量を低減することができる酸化槽、海水排煙脱硫システムおよび発電システムを提供することを課題とする。 In view of the above problems, the present invention provides an oxidation tank, a seawater flue gas desulfurization system, and a power generation system that can efficiently process sulfur-absorbing seawater and reduce the total amount of air supplied into the oxidation tank. This is the issue.
　上述した課題を解決するための本発明の第１の発明は、槽本体と連結し、排煙脱硫吸収塔から排出される硫黄分を含んだ硫黄分吸収海水に希釈用の海水を供給する希釈用海水供給手段と、前記槽本体内に設けられ、前記排煙脱硫吸収塔から排出される前記硫黄分吸収海水に空気を供給する複数の空気供給手段と、前記槽本体内に設けられ、前記硫黄分吸収海水中の溶存酸素濃度を測定する溶存酸素濃度測定装置と、を有し、予め求めた酸化槽の長さと硫黄分吸収海水中の溶存酸素濃度との関係に基づいて、前記空気供給手段から前記硫黄分吸収海水に供給する空気量を調整することを特徴とする酸化槽である。 1st invention of this invention for solving the subject mentioned above is the dilution which connects with a tank main body, and supplies the seawater for dilution to the sulfur content absorption seawater containing the sulfur content discharged | emitted from a flue gas desulfurization absorption tower Seawater supply means, a plurality of air supply means provided in the tank main body, for supplying air to the sulfur-absorbing seawater discharged from the flue gas desulfurization absorption tower, provided in the tank main body, A dissolved oxygen concentration measuring device for measuring the dissolved oxygen concentration in the sulfur-absorbing seawater, and the air supply based on the relationship between the length of the oxidation tank determined in advance and the dissolved oxygen concentration in the sulfur-absorbing seawater The oxidation tank is characterized in that the amount of air supplied from the means to the sulfur-absorbing seawater is adjusted.
　第２の発明は、第１の発明において、前記硫黄分吸収海水のｐＨ、亜硫酸濃度、アルカリ性、温度の何れか１つ以上と溶存酸素濃度との関係を予め算出し、前記溶存酸素濃度は、予め算出された前記硫黄分吸収海水のｐＨ、亜硫酸濃度、アルカリ性、温度の何れか１つ以上に基づいて求められることを特徴とする酸化槽である。 According to a second invention, in the first invention, the relationship between any one or more of pH, sulfurous acid concentration, alkalinity, and temperature of the sulfur-absorbing seawater and the dissolved oxygen concentration is calculated in advance, The oxidation tank is obtained based on any one or more of pH, sulfurous acid concentration, alkalinity, and temperature of the sulfur-absorbing seawater calculated in advance.
　第３の発明は、第１または第２の発明において、前記空気供給手段は、前記硫黄分吸収海水に前記空気を間隔をおきながら供給することを特徴とする酸化槽である。 The third invention is the oxidation tank according to the first or second invention, wherein the air supply means supplies the air to the sulfur-absorbing seawater at intervals.
　第４の発明は、第１乃至第３の何れか１つの発明において、前記空気供給手段は、前記硫黄分吸収海水の溶存酸素濃度が所定値以下となった時に供給することを特徴とする酸化槽である。 According to a fourth invention, in any one of the first to third inventions, the air supply means supplies when the dissolved oxygen concentration of the sulfur-absorbing seawater becomes a predetermined value or less. It is a tank.
　第５の発明は、排ガスと海水とを気液接触して前記排ガスを洗浄する排煙脱硫吸収塔と、前記排煙脱硫吸収塔の後流側に設けられ、第１乃至第４の何れか１つの発明の酸化槽と、前記海水を前記排煙脱硫吸収塔に供給する海水供給ラインと、前記排煙脱硫吸収塔から排出される前記硫黄分吸収海水を前記酸化槽に供給する硫黄分吸収海水排出ラインと、前記海水を前記硫黄分吸収海水排出ラインと前記酸化槽との何れか一方または両方に供給する希釈海水供給ラインと、を有することを特徴とする海水排煙脱硫システムである。 5th invention is provided in the exhaust gas desulfurization absorption tower which carries out gas-liquid contact of waste gas and seawater, and is provided in the downstream of the said flue gas desulfurization absorption tower, and is any 1st thru | or 4th An oxidation tank of one invention, a seawater supply line for supplying the seawater to the flue gas desulfurization absorption tower, and a sulfur content absorption for supplying the sulfur content absorption seawater discharged from the flue gas desulfurization absorption tower to the oxidation tank A seawater flue gas desulfurization system comprising: a seawater discharge line; and a diluted seawater supply line that supplies the seawater to one or both of the sulfur-absorbing seawater discharge line and the oxidation tank.
　第６の発明は、ボイラと、前記ボイラから排出される排ガスを蒸気発生用の熱源として使用すると共に、発生した蒸気を用いて発電機を駆動する蒸気タービンと、第５の発明の海水排煙脱硫システムとを有し、前記蒸気タービンで凝縮した水を回収し、循環させる復水器と、前記ボイラから排出される排ガスの脱硝を行う排煙脱硝装置と、前記排ガス中の煤塵を除去する集塵装置と、を有することを特徴とする発電システムである。 6th invention uses the boiler, the exhaust gas discharged | emitted from the said boiler as a heat source for steam generation, drives a generator using the generated steam, and the seawater flue gas of 5th invention A condenser having a desulfurization system for collecting and circulating water condensed by the steam turbine, a flue gas denitration device for denitrating exhaust gas discharged from the boiler, and removing dust in the exhaust gas And a dust collecting device.
　本発明によれば、硫黄分吸収海水の処理を効率良く行い、酸化槽内に供給される総空気量を低減することができる。 According to the present invention, it is possible to efficiently treat sulfur-absorbing seawater and reduce the total amount of air supplied into the oxidation tank.
図１は、本発明による実施例１に係る酸化槽を適用した海水排煙脱硫システムの構成を示す概略図である。FIG. 1 is a schematic diagram showing the configuration of a seawater flue gas desulfurization system to which an oxidation tank according to Example 1 of the present invention is applied. 図２は、酸化槽の長さと硫黄分吸収海水中の溶存酸素濃度との関係の一例を示す図である。FIG. 2 is a diagram showing an example of the relationship between the length of the oxidation tank and the dissolved oxygen concentration in the sulfur-absorbing seawater. 図３は、酸化槽の長さと硫黄分吸収海水に溶解しているＳＯ3 -濃度および溶存酸素濃度との関係の一例を示す説明図である。FIG. 3 is an explanatory diagram showing an example of the relationship between the length of the oxidation tank and the SO 3 − concentration and dissolved oxygen concentration dissolved in the sulfur-absorbing seawater. 図４は、酸化槽の長さと空気供給量との関係を示す説明図である。FIG. 4 is an explanatory diagram showing the relationship between the length of the oxidation tank and the air supply amount. 図５は、本発明の実施例２に係る発電システムの構成を示す概略図である。FIG. 5 is a schematic diagram illustrating a configuration of a power generation system according to Embodiment 2 of the present invention.
　以下、本発明につき図面を参照しつつ詳細に説明する。なお、下記の実施例により本発明が限定されるものではない。また、下記実施例における構成要素には、当業者が容易に想定できるもの、実質的に同一のもの、いわゆる均等の範囲のものが含まれる。さらに、下記実施例で開示した構成要素は適宜組み合わせることが可能である。 Hereinafter, the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by the following Example. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art, those that are substantially the same, and those in a so-called equivalent range. Furthermore, the constituent elements disclosed in the following embodiments can be appropriately combined.
　本発明による実施例１に係る酸化槽を適用した海水排煙脱硫システムについて、図面を参照して説明する。図１は、本発明による実施例１に係る酸化槽を適用した海水排煙脱硫システムの構成を示す概略図である。図１に示すように、海水排煙脱硫システム１０は、排煙脱硫吸収塔１１と、本実施例に係る酸化槽１２と、海水１３を排煙脱硫吸収塔１１に供給する海水供給ラインＬ１１、Ｌ１２と、排煙脱硫吸収塔１１から排出される硫黄分を含んだ硫黄分吸収海水１４を酸化槽１２に供給する硫黄分吸収海水排出ラインＬ１３と、海水１３を硫黄分吸収海水排出ラインＬ１３、酸化槽１２に供給する希釈海水供給ラインＬ１４、Ｌ１５と、を有する。 A seawater flue gas desulfurization system to which an oxidation tank according to Example 1 of the present invention is applied will be described with reference to the drawings. FIG. 1 is a schematic diagram showing the configuration of a seawater flue gas desulfurization system to which an oxidation tank according to Example 1 of the present invention is applied. As shown in FIG. 1, the seawater flue gas desulfurization system 10 includes a flue gas desulfurization absorption tower 11, an oxidation tank 12 according to this embodiment, and a seawater supply line L <b> 11 that supplies seawater 13 to the flue gas desulfurization absorption tower 11. L12, a sulfur-absorbing seawater discharge line L13 for supplying the sulfur-absorbing seawater 14 containing sulfur discharged from the flue gas desulfurization absorption tower 11 to the oxidation tank 12, and a seawater 13 for the sulfur-absorbing seawater discharge line L13. Diluted seawater supply lines L14 and L15 to be supplied to the oxidation tank 12.
　海水１３は海２１からポンプ２２により海水供給ラインＬ１１に汲み上げられ、一部の海水１３は吸収海水１３ａとしてポンプ２３または重力駆動により海水供給ラインＬ１２を介して排煙脱硫吸収塔１１に供給される。残りの海水１３の一部は希釈海水１３ｂとして希釈海水供給ラインＬ１４を介して硫黄分吸収海水排出ラインＬ１３に送給され、希釈海水１３ｂの残りは希釈海水１３ｃとして希釈海水供給ラインＬ１５を介して酸化槽１２に供給される。海水１３は、海２１からポンプ２２により直接汲み上げた海水を用いているが、本発明はこれに限定されるものではなく、図示しない復水器から排出される海水の排液などを用いるようにしてもよい。 The seawater 13 is pumped from the sea 21 to the seawater supply line L11 by the pump 22, and a part of the seawater 13 is supplied to the flue gas desulfurization absorption tower 11 via the seawater supply line L12 by the pump 23 or gravity drive as the absorbed seawater 13a. . A part of the remaining seawater 13 is supplied as diluted seawater 13b to the sulfur-absorbing seawater discharge line L13 via the diluted seawater supply line L14, and the remainder of the diluted seawater 13b is supplied as diluted seawater 13c via the diluted seawater supply line L15. It is supplied to the oxidation tank 12. As the seawater 13, seawater pumped directly from the sea 21 by the pump 22 is used. However, the present invention is not limited to this, and seawater discharged from a condenser (not shown) is used. May be.
　排煙脱硫吸収塔１１は、排ガス２５と吸収海水１３ａとを気液接触して排ガス２５を浄化する塔である。排煙脱硫吸収塔１１では、吸収海水１３ａは噴霧ノズル２６より上方に液柱状に噴出させ、排ガス２５と海水供給ラインＬ１２を介して供給される吸収海水１３ａとを気液接触させて、排ガス２５中の硫黄分の脱硫を行っている。本実施例では、噴霧ノズル２６は、上方に液柱状に噴出させる噴霧ノズルであるが、これに限定されるものではなく、下方にシャワー状に噴霧するようにしてもよい。 The flue gas desulfurization absorption tower 11 is a tower that purifies the exhaust gas 25 by gas-liquid contact between the exhaust gas 25 and the absorbed seawater 13a. In the flue gas desulfurization absorption tower 11, the absorbed seawater 13a is ejected in a liquid column shape above the spray nozzle 26, and the exhaust gas 25 and the absorbed seawater 13a supplied via the seawater supply line L12 are brought into gas-liquid contact. Desulfurization of the sulfur content in it. In the present embodiment, the spray nozzle 26 is a spray nozzle that ejects upward in the form of a liquid column, but is not limited thereto, and may be sprayed downward in the form of a shower.
　即ち、排煙脱硫吸収塔１１において排ガス２５と吸収海水１３ａとを気液接触させて、下記式（I）に示すような反応を生じさせ、排ガス２５中のＳＯ2などの形態で含有されているＳＯｘなどの硫黄分を吸収海水１３ａに吸収させ、排ガス２５中の硫黄分を、吸収海水１３ａを用いて除去している。
ＳＯ2（ｇ）　＋　Ｈ2Ｏ　→　Ｈ2ＳＯ3（ｌ）　→　ＨＳＯ3 -　＋　Ｈ＋　　　・・・（I） That is, the exhaust gas 25 and the absorbed seawater 13a are brought into gas-liquid contact in the flue gas desulfurization absorption tower 11 to cause a reaction represented by the following formula (I), and contained in the form of SO 2 or the like in the exhaust gas 25. The sulfur content such as SOx is absorbed by the absorption seawater 13a, and the sulfur content in the exhaust gas 25 is removed using the absorption seawater 13a.
SO 2 (g) + H 2 O → H 2 SO 3 (l) → HSO 3 − + H + (I)
　この海水脱硫により吸収海水１３ａと排ガス２５との気液接触により発生したＨ2ＳＯ3が解離して水素イオン（Ｈ+）が吸収海水１３ａ中に遊離するためｐＨが下がり、硫黄分吸収海水１４には多量の硫黄分が吸収される。このため、硫黄分吸収海水１４は硫黄分を高濃度に含んでいる。このとき、硫黄分吸収海水１４のｐＨとしては、例えば３～６程度となる。そして、排煙脱硫吸収塔１１で硫黄分を吸収した硫黄分吸収海水１４は、排煙脱硫吸収塔１１の塔底部に貯留される。排煙脱硫吸収塔１１の塔底部に貯留された硫黄分吸収海水１４は、硫黄分吸収海水排出ラインＬ１３を介して酸化槽１２に送給される。 Due to this seawater desulfurization, H 2 SO 3 generated by gas-liquid contact between the absorbed seawater 13a and the exhaust gas 25 is dissociated and hydrogen ions (H + ) are liberated in the absorbed seawater 13a, so that the pH is lowered, and the sulfur content-absorbing seawater 14 A large amount of sulfur is absorbed in For this reason, the sulfur-absorbing seawater 14 contains a high concentration of sulfur. At this time, the pH of the sulfur-absorbing seawater 14 is about 3 to 6, for example. And the sulfur content absorption seawater 14 which absorbed the sulfur content in the flue gas desulfurization absorption tower 11 is stored in the tower bottom part of the flue gas desulfurization absorption tower 11. The sulfur-absorbing seawater 14 stored at the bottom of the flue gas desulfurization absorption tower 11 is fed to the oxidation tank 12 via the sulfur-absorbing seawater discharge line L13.
　また、排煙脱硫吸収塔１１で脱硫された浄化ガス２８は浄化ガス排出通路Ｌ１６を介して大気中に放出される。 Further, the purified gas 28 desulfurized by the flue gas desulfurization absorption tower 11 is released into the atmosphere through the purified gas discharge passage L16.
　また、硫黄分吸収海水排出ラインＬ１３には希釈海水供給ラインＬ１４が連結され、硫黄分吸収海水排出ラインＬ１３内の硫黄分吸収海水１４を希釈海水１３ｂと混合し、希釈する。硫黄分吸収海水１４を希釈海水１３ｂと混合し、希釈することで、硫黄分吸収海水排出ラインＬ１３内の硫黄分吸収海水１４のｐＨを上昇させ、ＳＯ2ガスの再放散を防ぐことができる。また、硫黄分吸収海水排出ラインＬ１３においてＳＯ2が放散され、外部に漏洩するのを防止することで、刺激臭を放つのを防止することができる。 Moreover, the diluted seawater supply line L14 is connected to the sulfur content absorption seawater discharge line L13, and the sulfur content absorption seawater 14 in the sulfur content absorption seawater discharge line L13 is mixed with the diluted seawater 13b and diluted. By mixing and diluting the sulfur-absorbing seawater 14 with the diluted seawater 13b, the pH of the sulfur-absorbing seawater 14 in the sulfur-absorbing seawater discharge line L13 can be increased, and re-emission of SO 2 gas can be prevented. Also, SO 2 in the sulfur content absorbed seawater discharge line L13 is dissipated, preventing the leaking to the outside, it can be prevented from emitting a pungent odor.
　また、硫黄分吸収海水排出ラインＬ１３には硫黄分吸収海水１４を希釈海水１３ｂと希釈・混合する希釈混合槽を設けるようにしてもよい。硫黄分吸収海水１４は希釈混合槽において希釈海水１３ｂと混合され、希釈される。硫黄分吸収海水１４を希釈海水１３ｂと混合し、希釈することで、希釈混合槽内の硫黄分吸収海水１４のｐＨを上昇させ、ＳＯ2ガスの再放散を防ぐことができる。また、希釈混合槽においてＳＯ2が放散され、外部に漏洩するのを防止することで、刺激臭を放つのを防止することができる。 Moreover, you may make it provide the dilution mixing tank which dilutes and mixes the sulfur content absorption seawater 14 with the dilution seawater 13b in the sulfur content absorption seawater discharge line L13. The sulfur-absorbing seawater 14 is mixed with the diluted seawater 13b in the dilution mixing tank and diluted. By mixing and diluting the sulfur-absorbing seawater 14 with the diluted seawater 13b, the pH of the sulfur-absorbing seawater 14 in the dilution mixing tank can be raised, and re-emission of SO 2 gas can be prevented. Further, by preventing SO 2 from being diffused and leaking to the outside in the diluting / mixing tank, it is possible to prevent emitting an irritating odor.
　酸化槽１２は、排煙脱硫吸収塔１１の後流側に設けられ、希釈用海水供給手段として希釈海水供給ラインＬ１５と、空気供給手段として曝気装置（エアレーション装置）３１と、溶存酸素濃度測定装置３２とを有する槽である。なお、本実施例においては、希釈海水供給ラインＬ１５を設け、酸化槽１２に希釈海水１３ｃを供給するようにしているが、これに限定されるものではなく、希釈海水供給ラインＬ１５は設けなくてもよい。 The oxidation tank 12 is provided on the downstream side of the flue gas desulfurization absorption tower 11, and is a diluted seawater supply line L15 as dilution seawater supply means, an aeration device (aeration apparatus) 31 as air supply means, and a dissolved oxygen concentration measurement device. 32. In this embodiment, the diluted seawater supply line L15 is provided and the diluted seawater 13c is supplied to the oxidation tank 12. However, the present invention is not limited to this, and the diluted seawater supply line L15 is not provided. Also good.
　希釈海水供給ラインＬ１５は、希釈海水供給ラインＬ１４と酸化槽１２とを連結し、酸化槽１２内の硫黄分吸収海水１４に希釈海水１３ｃを供給するものである。 The diluted seawater supply line L15 connects the diluted seawater supply line L14 and the oxidation tank 12, and supplies the diluted seawater 13c to the sulfur-absorbing seawater 14 in the oxidation tank 12.
　曝気装置３１は、酸化槽１２内に設けられ、硫黄分吸収海水１４に空気３３を供給するものである。本実施例では、曝気装置３１は、空気３３を供給する酸化用空気ブロア３４と、空気３３を送給する散気管３５と、空気３３を酸化槽１２内の硫黄分吸収海水１４に供給する酸化空気用ノズル３６とを有する。酸化用空気ブロア３４により外部の空気３３が散気管３５を介して酸化空気用ノズル３６から酸化槽１２内に送り込まれ、下記式（II）のような酸素の溶解を生じる。酸化槽１２において硫黄分吸収海水１４中の硫黄分が空気３３と接触して下記式（III）～（V）のような亜硫酸水素イオン（ＨＳＯ3 -）の酸化反応と、重炭酸イオン（ＨＣＯ3 -）の脱炭酸反応とを生じ、硫黄分吸収海水１４は水質回復され、水質回復海水３７となる。なお、酸化空気用ノズル３６の数は特に限定されるものではなく、酸化槽１２内部の大きさに応じて適宜設けるようにする。
Ｏ2(ｇ)　→　Ｏ2（ｌ）・・・（II）
ＨＳＯ3 -　＋　１／２Ｏ2　→　ＳＯ4 2-　＋　Ｈ＋　・・・（III）
ＨＣＯ3 -　＋　Ｈ＋　→　ＣＯ2（ｇ）　＋　Ｈ2Ｏ　・・・（IV）
ＣＯ3 2-　＋２Ｈ＋　→　ＣＯ2（ｇ）　＋　Ｈ2Ｏ　・・・（V） The aeration apparatus 31 is provided in the oxidation tank 12 and supplies air 33 to the sulfur-absorbing seawater 14. In the present embodiment, the aeration apparatus 31 includes an oxidation air blower 34 that supplies air 33, an air diffuser 35 that supplies air 33, and an oxidation that supplies air 33 to the sulfur-absorbing seawater 14 in the oxidation tank 12. And an air nozzle 36. The external air 33 is sent from the oxidizing air nozzle 36 into the oxidation tank 12 through the air diffuser 35 by the oxidizing air blower 34, and oxygen is dissolved as shown in the following formula (II). In the oxidation tank 12, the sulfur content in the sulfur-absorbing seawater 14 comes into contact with the air 33, and an oxidation reaction of bisulfite ions (HSO 3 − ) such as the following formulas (III) to (V) and bicarbonate ions (HCO 3 - produce and decarboxylation), sulfur absorbing seawater 14 is water recovered, the water recovery seawater 37. The number of the oxidizing air nozzles 36 is not particularly limited, and is appropriately provided according to the size of the inside of the oxidation tank 12.
O 2 (g) → O 2 (l) (II)
HSO 3 − + 1 / 2O 2 → SO 4 2− + H + (III)
HCO 3 − + H + → CO 2 (g) + H 2 O (IV)
CO 3 2- + 2H + → CO 2 (g) + H 2 O (V)
　これにより、硫黄分吸収海水１４のｐＨを上昇させると共に、化学的酸素要求量（ＣＯＤ：Chemical　Oxygen　Demand）を低減することができ、水質回復海水３７のｐＨ、溶存酸素濃度、ＣＯＤを海水放流可能なレベルとして放出することができる。また、酸化槽１２で硫黄分吸収海水１４の水質回復を行う際にガスが発生しても、この発生するガスはＳＯ2環境基準濃度を満たすようにして酸化槽１２で放散させることができる。水質回復海水３７は海水排出ラインＬ１７を介して海２１へ放流される。 As a result, the pH of the sulfur-absorbing seawater 14 can be raised and the chemical oxygen demand (COD) can be reduced, and the pH, dissolved oxygen concentration, and COD of the water-recovered seawater 37 can be discharged into the seawater. Can be released as any level. Moreover, even if gas is generated when the water quality of the sulfur-absorbing seawater 14 is recovered in the oxidation tank 12, the generated gas can be diffused in the oxidation tank 12 so as to satisfy the SO 2 environmental standard concentration. The water quality recovery seawater 37 is discharged into the sea 21 through the seawater discharge line L17.
　また、溶存酸素濃度測定装置３２が酸化槽１２内に設けられており、硫黄分吸収海水１４中の溶存酸素濃度を測定している。溶存酸素濃度測定装置３２は酸化槽１２内の硫黄分吸収海水１４の流れ方向に複数設けられる。溶存酸素濃度測定装置３２としては、例えば、市販のポータブル型、定置型などの溶存酸素計が挙げられる。溶存酸素濃度測定装置３２で測定された測定結果は制御装置３８に伝達される。 Also, a dissolved oxygen concentration measuring device 32 is provided in the oxidation tank 12 to measure the dissolved oxygen concentration in the sulfur-absorbing seawater 14. A plurality of dissolved oxygen concentration measuring devices 32 are provided in the flow direction of the sulfur-absorbing seawater 14 in the oxidation tank 12. Examples of the dissolved oxygen concentration measuring device 32 include commercially available portable oxygen and stationary oxygen meters. The measurement result measured by the dissolved oxygen concentration measuring device 32 is transmitted to the control device 38.
　本実施例においては、溶存酸素濃度は、硫黄分吸収海水１４のｐＨ、亜硫酸濃度、アルカリ性、温度の何れか１つ以上に基づいて求めることができる。硫黄分吸収海水１４のｐＨ、亜硫酸濃度、アルカリ性、温度の何れか１つ以上と溶存酸素濃度との関係を予め算出しておき、制御装置３８は、予め算出された硫黄分吸収海水１４のｐＨ、亜硫酸濃度、アルカリ性、温度の何れか１つ以上と溶存酸素濃度との関係に基づいて、硫黄分吸収海水１４のｐＨ、亜硫酸濃度、アルカリ性、温度の何れか１つ以上の値から溶存酸素濃度を求める。 In this embodiment, the dissolved oxygen concentration can be determined based on any one or more of pH, sulfurous acid concentration, alkalinity, and temperature of the sulfur-absorbing seawater 14. The relationship between any one or more of the pH, sulfurous acid concentration, alkalinity, and temperature of the sulfur-absorbing seawater 14 and the dissolved oxygen concentration is calculated in advance, and the controller 38 calculates the pH of the sulfur-absorbing seawater 14 calculated in advance. Based on the relationship between any one or more of sulfite concentration, alkalinity, and temperature and the dissolved oxygen concentration, the dissolved oxygen concentration from any one or more of pH, sulfite concentration, alkalinity, and temperature of the sulfur-absorbing seawater 14 Ask for.
　本実施例においては、制御装置３８は、予め求めた酸化槽１２の長さと硫黄分吸収海水１４中の溶存酸素濃度との関係に基づいて、曝気装置３１の各々の酸化空気用ノズル３６から硫黄分吸収海水１４に供給する空気３３の空気量を調整している。 In the present embodiment, the control device 38 determines the sulfur from each oxidized air nozzle 36 of the aeration device 31 based on the relationship between the length of the oxidation tank 12 and the dissolved oxygen concentration in the sulfur-absorbing seawater 14 determined in advance. The amount of air 33 supplied to the partial absorption seawater 14 is adjusted.
　酸化槽１２の長さと硫黄分吸収海水１４中の溶存酸素濃度との関係の一例を図２に示す。図２に示すように、酸化槽１２の長さと硫黄分吸収海水１４中の溶存酸素濃度との関係を示す関係図を用いて各々の曝気装置３１から硫黄分吸収海水１４に供給する空気３３の空気量を調整することができる。 An example of the relationship between the length of the oxidation tank 12 and the dissolved oxygen concentration in the sulfur-absorbing seawater 14 is shown in FIG. As shown in FIG. 2, the relationship between the length of the oxidation tank 12 and the dissolved oxygen concentration in the sulfur-absorbing seawater 14 is used to determine the air 33 supplied to the sulfur-absorbing seawater 14 from each aeration device 31. The amount of air can be adjusted.
　曝気装置３１は、硫黄分吸収海水１４に空気３３を間隔を空けながら供給することが好ましい。本実施例において、間隔を空けながら供給とは、すべての酸化空気用ノズル３６から硫黄分吸収海水１４に空気３３を常時供給する場合以外の意味をいい、酸化槽１２の長さ方向に間隔を保ちながら限定された酸化空気用ノズル３６から硫黄分吸収海水１４に空気３３を供給することをいう。 It is preferable that the aeration apparatus 31 supplies the air 33 to the sulfur-absorbing seawater 14 with an interval. In the present embodiment, the supply with a gap means a meaning other than the case where the air 33 is constantly supplied from all the oxidized air nozzles 36 to the sulfur-absorbing seawater 14. This means that the air 33 is supplied to the sulfur-absorbing seawater 14 from the limited oxidizing air nozzle 36 while being maintained.
　曝気装置３１は、硫黄分吸収海水１４の溶存酸素濃度が所定値以下となった時に供給することが好ましい。所定値とは、十分な酸化速度を確保できる量をいい、例えば硫黄分吸収海水１４の溶存酸素濃度が飽和濃度の１／３以下になったら供給する。なお、この所定値は、溶存酸素濃度が飽和濃度の１／３の場合に限定されるものではない。 The aeration apparatus 31 is preferably supplied when the dissolved oxygen concentration of the sulfur-absorbing seawater 14 becomes a predetermined value or less. The predetermined value refers to an amount that can secure a sufficient oxidation rate. This predetermined value is not limited to the case where the dissolved oxygen concentration is 1/3 of the saturated concentration.
　曝気装置３１は、硫黄分吸収海水１４に空気３３を供給する際には、酸化槽１２の上流側に空気３３を多く供給し、酸化槽１２の下流側に行くほど空気３３の供給量を低減するのが好ましい。これは、酸化槽１２に供給された空気３３は直ぐに硫黄分吸収海水１４に溶解している亜硫酸イオン（ＳＯ3 -）の酸化や、ＣＯ2曝気に消費されないことから、硫黄分吸収海水１４が酸化槽１２の下流側に流れる。また、酸化槽１２の上流側はＳＯ3 -の濃度が高く、酸化が進みやすいため、硫黄分吸収海水１４中の溶存酸素が少なくなりやすい傾向にある。従って、硫黄分吸収海水１４に溶解しているＳＯ3 -が酸化される反応時間、ＣＯ2曝気に必要な時間を考慮して、酸化槽１２の上流側で空気３３を多く供給し、酸化槽１２の下流側では空気３３の供給量を低減することで、酸化槽１２内で硫黄分吸収海水１４のＳＯ3 -濃度を確実に低減できるためである。 When supplying the air 33 to the sulfur-absorbing seawater 14, the aeration apparatus 31 supplies a large amount of air 33 to the upstream side of the oxidation tank 12 and reduces the supply amount of the air 33 as it goes downstream of the oxidation tank 12. It is preferable to do this. This is because the air 33 supplied to the oxidation tank 12 is not immediately consumed by the oxidation of sulfite ions (SO 3 − ) dissolved in the sulfur-absorbing seawater 14 or CO 2 aeration. It flows downstream of the oxidation tank 12. Further, since the concentration of SO 3 − is high on the upstream side of the oxidation tank 12 and the oxidation easily proceeds, the dissolved oxygen in the sulfur-absorbing seawater 14 tends to decrease. Accordingly, in consideration of the reaction time during which SO 3 − dissolved in the sulfur-absorbing seawater 14 is oxidized and the time required for CO 2 aeration, a large amount of air 33 is supplied upstream of the oxidation tank 12, and the oxidation tank This is because the SO 3 − concentration of the sulfur-absorbing seawater 14 can be reliably reduced in the oxidation tank 12 by reducing the supply amount of the air 33 on the downstream side of the air 12.
　図３は、酸化槽１２の長さと硫黄分吸収海水１４に溶解しているＳＯ3 -濃度および溶存酸素濃度との関係の一例を示す説明図である。図３に示すように、酸化槽１２内に空気３３を間隔を空けて供給するようにしている場合でも、硫黄分吸収海水１４の溶存酸素濃度が所定の設定値αとなった時点で酸化槽１２内に空気３３を間隔を空けて供給すると共にその供給量を調整することで、硫黄分吸収海水１４中のＳＯ3 -濃度を酸化槽１２内に空気３３を常時供給するようにしている場合とほぼ同等に低減することができる。 FIG. 3 is an explanatory diagram showing an example of the relationship between the length of the oxidation tank 12 and the SO 3 − concentration and dissolved oxygen concentration dissolved in the sulfur-absorbing seawater 14. As shown in FIG. 3, even when the air 33 is supplied into the oxidation tank 12 at intervals, the oxidation tank when the dissolved oxygen concentration of the sulfur-absorbing seawater 14 reaches a predetermined set value α. The air 33 is supplied to the oxidant tank 12 at intervals, and the supply amount is adjusted so that the SO 3 − concentration in the sulfur-absorbing seawater 14 is constantly supplied to the oxidizer 12. Can be reduced to almost the same.
　また、酸化槽１２内に空気３３を間隔を空けて供給することで、硫黄分吸収海水１４中に溶解しているＳＯ3 -濃度を所定値以下にするまでに要する酸化槽１２の長さが変化する場合でも、酸化槽１２の深さ、流路幅を調整して硫黄分吸収海水１４の流速が遅くなるように調整することで、硫黄分吸収海水１４を再生し、放出するのに要する酸化槽１２の長さを、従来のように酸化槽１２内に空気３３を常時供給して硫黄分吸収海水１４を再生し、放出するのに要する酸化槽１２の長さと同等程度となるように調整することができる。 Further, the length of the oxidation tank 12 required to reduce the SO 3 − concentration dissolved in the sulfur-absorbing seawater 14 to a predetermined value or less by supplying the air 33 into the oxidation tank 12 at intervals. Even when it changes, it is necessary to regenerate and release the sulfur-absorbing seawater 14 by adjusting the depth and flow path width of the oxidation tank 12 so that the flow rate of the sulfur-absorbing seawater 14 becomes slower. The length of the oxidation tank 12 is approximately equal to the length of the oxidation tank 12 required to regenerate and release the sulfur-absorbing seawater 14 by constantly supplying air 33 into the oxidation tank 12 as in the prior art. Can be adjusted.
　図４は、酸化槽１２の長さと空気供給量との関係を示す説明図である。図４に示すように、酸化槽１２の長手方向の長さを１．０とし、酸化槽１２の長さ方向に均等に５分割した各領域に空気３３を均等に供給した場合の酸化槽１２内に供給される総空気量比を１．０とする（比較例１参照）。このとき、実験例１のように、酸化槽１２を５分割したときの各領域の長さを変更し、各領域に供給する空気量を調整する。具体的には、酸化槽１２に空気３３を供給する領域の長さを長めとし、空気３３を供給しない領域の長さは短くし、酸化槽１２内に供給される空気量は、酸化槽１２の上流側ほど多くし、酸化槽１２の下流側に向かうほど少なくなるように調整する。 FIG. 4 is an explanatory diagram showing the relationship between the length of the oxidation tank 12 and the air supply amount. As shown in FIG. 4, the length of the oxidation tank 12 in the longitudinal direction is set to 1.0, and the oxidation tank 12 when the air 33 is uniformly supplied to each of the regions equally divided into five in the length direction of the oxidation tank 12. The ratio of the total air supplied to the inside is set to 1.0 (see Comparative Example 1). At this time, as in Experimental Example 1, the length of each region when the oxidation tank 12 is divided into five is changed, and the amount of air supplied to each region is adjusted. Specifically, the length of the region where the air 33 is supplied to the oxidation tank 12 is lengthened, the length of the region where the air 33 is not supplied is shortened, and the amount of air supplied into the oxidation tank 12 is It is adjusted so that it increases toward the downstream side of the oxidation tank 12 and decreases toward the downstream side of the oxidation tank 12.
　これにより、実験例１では、比較例１のように酸化槽１２内に各領域に空気３３を均等に常時供給する場合よりも酸化槽１２に供給する総空気量を例えば２０％程度低減することができる。よって、酸化槽１２を複数領域に分割したときの各領域の長さと各領域に供給する空気量を調整することにより、硫黄分吸収海水１４の処理を効率良く行うことができるため、酸化槽１２内の無駄な位置に曝気装置３１を設置するのを軽減することができると共に、酸化槽１２内に供給される総空気量を低減することができ、酸化槽１２内に必要以上に酸素を供給するのを低減することができる。 Thus, in Experimental Example 1, the total amount of air supplied to the oxidation tank 12 is reduced by, for example, about 20%, compared to the case where the air 33 is constantly and uniformly supplied to each region in the oxidation tank 12 as in Comparative Example 1. Can do. Therefore, by adjusting the length of each area when the oxidation tank 12 is divided into a plurality of areas and the amount of air supplied to each area, the sulfur-absorbing seawater 14 can be efficiently processed. It is possible to reduce the installation of the aeration device 31 at a useless position in the inside, and it is possible to reduce the total amount of air supplied into the oxidation tank 12 and supply oxygen more than necessary into the oxidation tank 12. Can be reduced.
　したがって、本実施例に係る酸化槽１２によれば、予め求めた酸化槽１２の長さと硫黄分吸収海水１４中の溶存酸素濃度との関係を示す関係図を用いて、曝気装置３１の各々の酸化空気用ノズル３６から硫黄分吸収海水１４に供給する空気３３の空気量を調整し、酸化槽１２を複数領域に分割したときの各領域の長さと各領域に供給する空気量を調整している。そのため、本実施例に係る酸化槽１２は、硫黄分吸収海水１４の処理を効率良く行うことで、酸化槽１２を大きくすることなく酸化槽１２内に設置される曝気装置３１の数を低減することができると共に、曝気装置３１から酸化槽１２内に供給する空気３３の総空気量を低減して空気３３を供給するために要する動力を低減することができる。 Therefore, according to the oxidation tank 12 which concerns on a present Example, each relationship of the aeration apparatus 31 is shown using the relationship figure which shows the relationship between the length of the oxidation tank 12 calculated | required previously, and the dissolved oxygen concentration in the sulfur content absorption seawater 14. FIG. The amount of air 33 supplied to the sulfur-absorbing seawater 14 from the oxidized air nozzle 36 is adjusted, and the length of each region when the oxidation tank 12 is divided into a plurality of regions and the amount of air supplied to each region are adjusted. Yes. Therefore, the oxidation tank 12 which concerns on a present Example reduces the number of the aeration apparatus 31 installed in the oxidation tank 12 by enlarging the oxidation tank 12 by processing the sulfur content absorption seawater 14 efficiently. In addition, it is possible to reduce the total air amount of the air 33 supplied from the aeration device 31 into the oxidation tank 12 and reduce the power required to supply the air 33.
　このように、本実施例に係る酸化槽１２を適用した海水排煙脱硫システム１０は、酸化槽１２内に設置される曝気装置３１の酸化空気用ノズル３６の数を低減できると共に、酸化槽１２内に供給する総空気量を低減し、空気３３を供給するために要する動力を低減することができるため、外開放型の酸化槽１２に流れた硫黄分吸収海水１４を効率良く酸化処理し、水質回復処理を行うことができる。 As described above, the seawater flue gas desulfurization system 10 to which the oxidation tank 12 according to the present embodiment is applied can reduce the number of oxidized air nozzles 36 of the aeration apparatus 31 installed in the oxidation tank 12 and also the oxidation tank 12. Since the total amount of air supplied into the interior can be reduced and the power required to supply the air 33 can be reduced, the sulfur-absorbing seawater 14 that has flowed into the outer open type oxidation tank 12 is efficiently oxidized, Water quality recovery treatment can be performed.
　したがって、本実施例に係る酸化槽１２を適用した海水排煙脱硫システム１０によれば、排煙脱硫吸収塔１１から排出される硫黄分吸収海水１４を、酸化槽１２において曝気装置３１の酸化空気用ノズル３６の数を低減しつつ効率良く酸化槽１２内に空気３３を供給することで、硫黄分吸収海水１４を効率良く処理し、水質回復処理を行うことができるため、信頼性の高い海水排煙脱硫システムを提供することができる。 Therefore, according to the seawater flue gas desulfurization system 10 to which the oxidation tank 12 according to the present embodiment is applied, the sulfur-absorbing seawater 14 discharged from the flue gas desulfurization absorption tower 11 is converted into the oxidized air of the aeration apparatus 31 in the oxidation tank 12. Since the air 33 is efficiently supplied into the oxidation tank 12 while reducing the number of nozzles 36, the sulfur-absorbing seawater 14 can be efficiently processed and the water quality recovery process can be performed. A flue gas desulfurization system can be provided.
　また、本実施例においては、排煙脱硫吸収塔１１で海水脱硫に用いた吸収海水１３ａの処理をする海水排煙脱硫システムについて説明したが、本発明はこれに限定されるものではない。海水排煙脱硫システムは、例えば、各種産業における工場、大型、中型火力発電所などの発電所、電気事業用大型ボイラまたは一般産業用ボイラ、製鉄所、精錬所等から排出される排ガス中に含まれる硫黄酸化物を海水脱硫する海水排煙脱硫装置にも適用することができる。 In the present embodiment, the seawater flue gas desulfurization system for treating the absorbed seawater 13a used for the seawater desulfurization in the flue gas desulfurization absorption tower 11 has been described, but the present invention is not limited to this. Seawater flue gas desulfurization system is included in exhaust gas discharged from, for example, factories in various industries, power plants such as large and medium-sized thermal power plants, large boilers for electric utilities or general industrial boilers, steelworks, smelters, etc. The present invention can also be applied to a seawater flue gas desulfurization apparatus that desulfurizes the generated sulfur oxides.
　また、本実施例においては、排煙脱硫吸収塔１１、酸化槽１２は各々別々の槽として独立しており、排煙脱硫吸収塔１１と酸化槽１２とを硫黄分吸収海水排出ラインＬ１３で連結するようにしているが、本実施例はこれに限定されるものではなく、排煙脱硫吸収塔１１、酸化槽１２を一体として１つの槽で構成してもよい。 In this embodiment, the flue gas desulfurization absorption tower 11 and the oxidation tank 12 are independent as separate tanks, and the flue gas desulfurization absorption tower 11 and the oxidation tank 12 are connected by a sulfur content absorption seawater discharge line L13. However, the present embodiment is not limited to this, and the flue gas desulfurization absorption tower 11 and the oxidation tank 12 may be integrated into a single tank.
　本発明の実施例２に係る発電システムについて、図面を参照して説明する。本実施例に係る発電システムに適用される海水排煙脱硫システムには、実施例１に係る海水排煙脱硫システムが用いられる。なお、実施例１と同様の部材については、同一符号を付してその説明は省略する。 A power generation system according to Example 2 of the present invention will be described with reference to the drawings. The seawater flue gas desulfurization system according to the first embodiment is used for the seawater flue gas desulfurization system applied to the power generation system according to the present embodiment. In addition, about the member similar to Example 1, the same code | symbol is attached | subjected and the description is abbreviate | omitted.
　図５は、本発明の実施例２に係る発電システムの構成を示す概略図である。図５に示すように、本実施例に係る発電システム４０は、ボイラ４１と、蒸気タービン４２と、復水器４３と、排煙脱硝装置４４と、集塵装置４５と、海水排煙脱硫システム１０とを有するものである。なお、本実施例において、上述のように、硫黄分吸収海水１４とは、海水排煙脱硫システム１０においてＳＯ2など硫黄分を吸収した使用済み海水をいう。 FIG. 5 is a schematic diagram illustrating a configuration of a power generation system according to Embodiment 2 of the present invention. As shown in FIG. 5, a power generation system 40 according to this embodiment includes a boiler 41, a steam turbine 42, a condenser 43, a flue gas denitration device 44, a dust collector 45, and a seawater flue gas desulfurization system. 10. In the present embodiment, as described above, the sulfur-absorbing seawater 14 is used seawater that has absorbed sulfur such as SO 2 in the seawater flue gas desulfurization system 10.
　ボイラ４１は、油タンクまたは石炭ミルなどから供給される燃料４６を空気予熱器（ＡＨ）４７で予熱された空気４８と共にバーナ（不図示）から噴射して燃焼させる。外部から供給される空気４８は押込みファン４９により空気予熱器４７に送給され予熱される。燃料４６と空気予熱器４７で予熱された空気４８とはバーナ（不図示）に供給され、燃料４６はボイラ４１で燃焼される。これにより、蒸気タービン４２を駆動するための蒸気５０を発生する。 The boiler 41 injects and burns fuel 46 supplied from an oil tank or a coal mill from a burner (not shown) together with air 48 preheated by an air preheater (AH) 47. The air 48 supplied from the outside is supplied to the air preheater 47 by the pushing fan 49 and preheated. The fuel 46 and the air 48 preheated by the air preheater 47 are supplied to a burner (not shown), and the fuel 46 is combusted by the boiler 41. Thereby, the steam 50 for driving the steam turbine 42 is generated.
　ボイラ４１内で燃焼して発生する排ガス５１は排煙脱硝装置４４に送給される。また、排ガス５１は復水器４３から排出される水５２と熱交換し、蒸気５０を発生するための熱源として使用される。蒸気タービン４２はこの発生した蒸気５０を用いて発電機５３を駆動している。そして、復水器４３は蒸気タービン４２で凝縮した水５２を回収し、再びボイラ４１に戻し、循環させている。 The exhaust gas 51 generated by combustion in the boiler 41 is sent to the flue gas denitration device 44. Further, the exhaust gas 51 is used as a heat source for exchanging heat with water 52 discharged from the condenser 43 and generating steam 50. The steam turbine 42 drives the generator 53 using the generated steam 50. The condenser 43 collects the water 52 condensed by the steam turbine 42 and returns it to the boiler 41 for circulation.
　ボイラ４１から排出された排ガス５１は排煙脱硝装置４４内で脱硝され、空気予熱器４７で空気４８と熱交換した後、集塵装置４５に送給され、排ガス５１中の煤塵を除去する。そして、集塵装置４５で除塵された排ガス５１は、誘引ファン５５により排煙脱硫吸収塔１１内に供給される。この時、排ガス５１は熱交換器５６で、排煙脱硫吸収塔１１で脱硫され排出される浄化ガス２８と熱交換された後、排煙脱硫吸収塔１１内に供給される。また、排ガス５１は熱交換器５６で浄化ガス２８と熱交換することなく排煙脱硫吸収塔１１に直接供給するようにしてもよい。 The exhaust gas 51 discharged from the boiler 41 is denitrated in the flue gas denitration device 44, exchanged heat with the air 48 by the air preheater 47, and then sent to the dust collector 45 to remove the dust in the exhaust gas 51. The exhaust gas 51 removed by the dust collector 45 is supplied into the flue gas desulfurization absorption tower 11 by the induction fan 55. At this time, the exhaust gas 51 is heat-exchanged by the heat exchanger 56 with the purified gas 28 desulfurized and discharged by the flue gas desulfurization absorption tower 11, and then supplied into the flue gas desulfurization absorption tower 11. Further, the exhaust gas 51 may be directly supplied to the flue gas desulfurization absorption tower 11 without exchanging heat with the purified gas 28 by the heat exchanger 56.
　また、熱交換器５６は、熱回収器と、再加熱器とを含むものであり、前記熱回収器と前記再加熱器との間を熱媒体が循環している。前記熱回収器は、誘引ファン５５と排煙脱硫吸収塔１１との間に設けられ、ボイラ４１から排出される排ガス５１と前記熱媒体とを熱交換する。前記再加熱器は、排煙脱硫吸収塔１１の後流側に設けられ、排煙脱硫吸収塔１１から排出される浄化ガス２８と前記熱媒体とを熱交換して、浄化ガス２８を再加熱する。 Further, the heat exchanger 56 includes a heat recovery device and a reheater, and a heat medium circulates between the heat recovery device and the reheater. The heat recovery unit is provided between the induction fan 55 and the flue gas desulfurization absorption tower 11 and exchanges heat between the exhaust gas 51 discharged from the boiler 41 and the heat medium. The reheater is provided on the downstream side of the flue gas desulfurization absorption tower 11, exchanges heat between the purified gas discharged from the flue gas desulfurization absorption tower 11 and the heat medium, and reheats the purified gas. To do.
　海水排煙脱硫システム１０は、上述の実施例１に係る海水排煙脱硫装置である。すなわち、海水排煙脱硫システム１０は、排煙脱硫吸収塔１１と、酸化槽１２と、海水供給ラインＬ１１、Ｌ１２と、硫黄分吸収海水排出ラインＬ１３と、希釈海水供給ラインＬ１４、Ｌ１５と、を有するものである。 The seawater flue gas desulfurization system 10 is the seawater flue gas desulfurization apparatus according to Example 1 described above. That is, the seawater flue gas desulfurization system 10 includes a flue gas desulfurization absorption tower 11, an oxidation tank 12, seawater supply lines L11 and L12, a sulfur content absorption seawater discharge line L13, and diluted seawater supply lines L14 and L15. It is what you have.
　海水排煙脱硫システム１０では、上述の通り、排ガス５１中に含有されている硫黄分を海２１から汲み上げられた海水１３を用いて海水脱硫を行っている。また、海水１３は海２１からポンプ２２により汲み上げられ、復水器４３で熱交換した後、一部の吸収海水１３ａは海水供給ラインＬ１２を介してポンプ２３により海水排煙脱硫システム１０に送給される。また、残りの希釈海水１３ｂは希釈海水供給ラインＬ１４を介して酸化槽１２の上流側に送給される。海水排煙脱硫システム１０において排ガス５１と吸収海水１３ａとを気液接触させて、排ガス５１中の硫黄分を吸収海水１３ａに吸収している。硫黄分を吸収した硫黄分吸収海水１４は排煙脱硫吸収塔１１から排出された後、希釈海水１３ｂと混合し、希釈され、酸化槽１２の上流側に送給される。また、海水排煙脱硫システム１０で浄化された排ガス５１は、浄化ガス２８となって浄化ガス排出通路Ｌ１６を介して煙突５７から外部に排出される。 In the seawater flue gas desulfurization system 10, as described above, the seawater desulfurization is performed using the seawater 13 pumped up from the sea 21 by sulfur contained in the exhaust gas 51. In addition, the seawater 13 is pumped from the sea 21 by the pump 22, and after heat exchange is performed by the condenser 43, a part of the absorbed seawater 13 a is supplied to the seawater flue gas desulfurization system 10 by the pump 23 via the seawater supply line L 12. Is done. The remaining diluted seawater 13b is fed to the upstream side of the oxidation tank 12 through the diluted seawater supply line L14. In the seawater flue gas desulfurization system 10, the exhaust gas 51 and the absorbed seawater 13a are brought into gas-liquid contact, and the sulfur content in the exhaust gas 51 is absorbed by the absorbed seawater 13a. The sulfur-absorbing seawater 14 that has absorbed the sulfur is discharged from the flue gas desulfurization absorption tower 11, mixed with diluted seawater 13 b, diluted, and fed upstream of the oxidation tank 12. Further, the exhaust gas 51 purified by the seawater flue gas desulfurization system 10 becomes the purified gas 28 and is discharged outside from the chimney 57 through the purified gas discharge passage L16.
　また、本実施例に係る発電システム４０は、希釈海水１３ｂの一部を希釈海水供給ラインＬ１５を介して酸化槽１２内の上流側に供給しているがこれに限定されるものではなく、希釈海水１３ｂの一部を希釈海水供給ラインＬ１５を介して酸化槽１２内の上流側に供給しなくてもよい。 Moreover, although the electric power generation system 40 which concerns on a present Example supplies a part of dilution seawater 13b to the upstream in the oxidation tank 12 via the dilution seawater supply line L15, it is not limited to this, Dilution A part of the seawater 13b may not be supplied to the upstream side in the oxidation tank 12 via the diluted seawater supply line L15.
　また、海２１から汲み上げられた海水１３は復水器４３で熱交換した後、海水排煙脱硫システム１０に送給し、海水脱硫に用いているが、海２１から汲み上げた海水１３を復水器４３で熱交換させずに海水排煙脱硫システム１０に直接送給し、海水脱硫に用いるようにしてもよい。 The seawater 13 pumped from the sea 21 is heat-exchanged by the condenser 43 and then sent to the seawater flue gas desulfurization system 10 for use in seawater desulfurization. The seawater 13 pumped from the sea 21 is condensed into water. Instead of heat exchange in the vessel 43, it may be directly fed to the seawater flue gas desulfurization system 10 and used for seawater desulfurization.
　希釈混合槽で硫黄分吸収海水１４を希釈海水１３ｂと混合した後、酸化槽１２に送給される。本実施例では、酸化槽１２は、希釈海水供給ラインＬ１５と、曝気装置３１と、溶存酸素濃度測定装置３２とを有している。制御装置３８は、溶存酸素濃度測定装置３２で測定された測定結果から、予め求めた酸化槽１２の長さと硫黄分吸収海水１４中の溶存酸素濃度との関係に基づいて、各々の曝気装置３１の酸化空気用ノズル３６から硫黄分吸収海水１４に供給する空気３３の空気量を調整する。酸化槽１２を複数領域に分割したときの各領域の長さと各領域に供給する空気量を調整することにより、硫黄分吸収海水１４の処理を効率良く行い、酸化槽１２を大きくすることなく酸化槽１２内に設置される曝気装置３１の数を低減することができると共に、曝気装置３１から酸化槽１２内に供給する空気３３の総空気量を低減して空気３３を供給するために要する動力を低減することができる。 After the sulfur-absorbing seawater 14 is mixed with the diluted seawater 13b in the dilution mixing tank, it is fed to the oxidation tank 12. In the present embodiment, the oxidation tank 12 has a diluted seawater supply line L15, an aeration device 31, and a dissolved oxygen concentration measurement device 32. Based on the measurement result measured by the dissolved oxygen concentration measuring device 32, the control device 38 determines each aeration device 31 based on the relationship between the length of the oxidation tank 12 and the dissolved oxygen concentration in the sulfur-absorbing seawater 14 obtained in advance. The amount of air 33 supplied to the sulfur-absorbing seawater 14 from the oxidized air nozzle 36 is adjusted. By adjusting the length of each region and the amount of air supplied to each region when the oxidation tank 12 is divided into a plurality of regions, the sulfur-absorbing seawater 14 is efficiently processed, and the oxidation tank 12 is not enlarged. The number of aeration devices 31 installed in the tank 12 can be reduced, and the power required to supply the air 33 by reducing the total amount of air 33 supplied from the aeration device 31 into the oxidation tank 12. Can be reduced.
　このようにして酸化槽１２で硫黄分吸収海水１４を水質回復し、水質回復海水３７を得る。酸化槽１２で得られた水質回復海水３７は、ｐＨ、溶存酸素濃度、ＣＯＤを海水放流可能なレベルとして酸化槽１２から海水排出ラインＬ１７を介して海２１へ放流される。 In this way, the water content of the sulfur-absorbing seawater 14 is recovered in the oxidation tank 12 to obtain water quality-recovered seawater 37. The water quality recovery seawater 37 obtained in the oxidation tank 12 is discharged from the oxidation tank 12 to the sea 21 via the seawater discharge line L17 with pH, dissolved oxygen concentration, and COD at a level at which seawater can be discharged.
　また、本実施例に係る発電システム４０は、海水供給ラインＬ１１から吸収海水１３ａおよび希釈海水１３ｂ以外に海水１３の一部を酸化槽１２の後流側に供給する希釈海水供給ラインＬ１８を備えている。本実施例に係る発電システム４０は、海水供給ラインＬ１１から海水１３の一部を希釈海水供給ラインＬ１８を介して酸化槽１２内の水質回復海水３７の後流側に供給するようにしている。これにより、水質回復海水３７を更に希釈することができる。この結果、水質回復海水３７のｐＨを上昇させ、海水排液のｐＨを海水２１のｐＨに近くなるまで上昇させ、海水排液のｐＨの排水基準（ｐＨ６．０以上）を満たすと共に、ＣＯＤを低減することができ、水質回復海水３７のｐＨ、ＣＯＤを海水放流可能なレベルとして放出することができる。なお、本実施例では、希釈海水供給ラインＬ１８を介して酸化槽１２内の下流側に供給するようにしているがこれに限定されるものではなく、希釈海水１３ｂの一部を希釈海水供給ラインＬ１８を介して酸化槽１２内の下流側に供給しなくてもよい。 Moreover, the electric power generation system 40 which concerns on a present Example is equipped with the diluted seawater supply line L18 which supplies a part of seawater 13 from the seawater supply line L11 to the downstream of the oxidation tank 12 other than the absorption seawater 13a and the diluted seawater 13b. Yes. The power generation system 40 according to the present embodiment supplies a part of the seawater 13 from the seawater supply line L11 to the downstream side of the water quality recovery seawater 37 in the oxidation tank 12 via the diluted seawater supply line L18. Thereby, the water quality recovery seawater 37 can be further diluted. As a result, the pH of the water quality recovery seawater 37 is increased, the pH of the seawater drainage is increased until it approaches the pH of the seawater 21, and the drainage standard (pH 6.0 or higher) of the pH of the seawater drainage is satisfied. The pH and COD of the water quality recovery seawater 37 can be released as a level at which seawater can be discharged. In this embodiment, the water is supplied to the downstream side in the oxidation tank 12 via the diluted seawater supply line L18. However, the present invention is not limited to this, and a part of the diluted seawater 13b is supplied to the diluted seawater supply line. It is not necessary to supply to the downstream side in the oxidation tank 12 via L18.
　このように、本実施例に係る発電システム４０によれば、酸化槽１２において、酸化槽１２内に設置される曝気装置３１の数を低減しつつ、効率良く酸化槽１２内に空気３３を供給することで、硫黄分吸収海水１４を効率良く処理し、酸化槽１２内に供給される総空気量を低減することができるため、酸化槽１２において硫黄分吸収海水１４へ空気３３を供給する動力を低減し、ランニングコストの抑制を図ることができる。したがって、本実施例に係る発電システム４０は、硫黄分吸収海水１４を効率良く安定して処理し、水質回復処理を行うことができるので、安全性および信頼性の高い発電システムを提供することができる。 Thus, according to the power generation system 40 according to the present embodiment, in the oxidation tank 12, the air 33 is efficiently supplied into the oxidation tank 12 while reducing the number of aeration devices 31 installed in the oxidation tank 12. By doing so, the sulfur-absorbing seawater 14 can be efficiently processed and the total amount of air supplied into the oxidation tank 12 can be reduced. Therefore, the power for supplying the air 33 to the sulfur-absorbing seawater 14 in the oxidation tank 12 This can reduce the running cost. Therefore, since the power generation system 40 according to the present embodiment can efficiently and stably process the sulfur-absorbing seawater 14 and perform water quality recovery processing, it is possible to provide a power generation system with high safety and reliability. it can.
　また、本実施例に係る海水排煙脱硫システム１０は、例えば、各種産業における工場、大型、中型火力発電所などの発電所、電気事業用大型ボイラまたは一般産業用ボイラ等から排出される排ガス中に含まれる硫黄酸化物を海水脱硫することで生じる硫黄分吸収溶液中の硫黄分の除去に利用することができる。 In addition, the seawater flue gas desulfurization system 10 according to the present embodiment is, for example, in exhaust gas discharged from factories in various industries, power plants such as large-sized and medium-sized thermal power plants, large boilers for electric utilities, or general industrial boilers. Can be used for removal of sulfur content in the sulfur content absorption solution produced by desulfurizing seawater.
　１０　海水排煙脱硫システム
　１１　排煙脱硫吸収塔
　１２　酸化槽
　１３　海水
　１３ａ　吸収海水
　１３ｂ、１３ｃ　希釈海水
　１４　硫黄分吸収海水
　２１　海
　２２、２３　ポンプ
　２５、５１　排ガス
　２６　噴霧ノズル
　２８　浄化ガス
　３１　曝気装置（エアレーション装置）
　３２　溶存酸素濃度測定装置
　３３　空気
　３４　酸化用空気ブロア
　３５　散気管
　３６　酸化空気用ノズル
　３７　水質回復海水
　３８　制御装置
　４０　発電システム
　４１　ボイラ
　４２　蒸気タービン
　４３　復水器
　４４　排煙脱硝装置
　４５　集塵装置
　４６　燃料
　４７　空気予熱器（ＡＨ）
　４８　空気
　４９　押込みファン
　５０　蒸気
　５２　水
　５３　発電機
　５５　誘引ファン
　５６　熱交換器
　５７　煙突
　Ｌ１１、Ｌ１２　海水供給ライン
　Ｌ１３　硫黄分吸収海水排出ライン
　Ｌ１４、Ｌ１５、Ｌ１８　希釈海水供給ライン
　Ｌ１６　浄化ガス排出通路
　Ｌ１７　海水排出ライン DESCRIPTION OF SYMBOLS 10 Seawater flue gas desulfurization system 11 Flue gas desulfurization absorption tower 12 Oxidation tank 13 Seawater 13a Absorption seawater 13b, 13c Diluted seawater 14 Sulfur content absorption seawater 21 Sea 22, 23 Pump 25, 51 Exhaust gas 26 Spray nozzle 28 Purified gas 31 Aeration apparatus ( Aeration equipment)
32 Dissolved oxygen concentration measuring device 33 Air 34 Oxidizing air blower 35 Aeration pipe 36 Oxidizing air nozzle 37 Water quality recovery seawater 38 Control device 40 Power generation system 41 Boiler 42 Steam turbine 43 Condenser 44 Flue gas denitration device 45 Dust collector 46 Fuel 47 Air preheater (AH)
48 Air 49 Push-in fan 50 Steam 52 Water 53 Generator 55 Induction fan 56 Heat exchanger 57 Chimney L11, L12 Seawater supply line L13 Sulfur component absorption seawater discharge line L14, L15, L18 Diluted seawater supply line L16 Purified gas discharge passage L17 Seawater Discharge line

Claims (6)

  1. 　槽本体と連結し、排煙脱硫吸収塔から排出される硫黄分を含んだ硫黄分吸収海水に希釈用の海水を供給する希釈用海水供給手段と、
    　前記槽本体内に設けられ、前記排煙脱硫吸収塔から排出される前記硫黄分吸収海水に空気を供給する空気供給手段と、
    　前記槽本体内に設けられ、前記硫黄分吸収海水中の溶存酸素濃度を測定する溶存酸素濃度測定装置と、
    を有し、
    　予め求めた酸化槽の長さと硫黄分吸収海水中の溶存酸素濃度との関係に基づいて、前記空気供給手段から前記硫黄分吸収海水に供給する空気の供給量を調整することを特徴とする酸化槽。     Seawater supply means for dilution that is connected to the tank body and supplies seawater for dilution to sulfur-absorbing seawater containing sulfur discharged from the flue gas desulfurization absorption tower,
    An air supply means provided in the tank body, for supplying air to the sulfur-absorbing seawater discharged from the flue gas desulfurization absorption tower;
    A dissolved oxygen concentration measuring device provided in the tank body for measuring the dissolved oxygen concentration in the sulfur-absorbing seawater;
    Have
    Oxidation characterized by adjusting the amount of air supplied from the air supply means to the sulfur-absorbing seawater based on the relationship between the length of the oxidation tank determined in advance and the dissolved oxygen concentration in the sulfur-absorbing seawater Tank.
  2. 　請求項１において、
    　前記硫黄分吸収海水のｐＨ、亜硫酸濃度、アルカリ性、温度の何れか１つ以上と溶存酸素濃度との関係を予め算出し、
    　前記溶存酸素濃度は、予め算出された前記硫黄分吸収海水のｐＨ、亜硫酸濃度、アルカリ性、温度の何れか１つ以上に基づいて求められることを特徴とする酸化槽。     In claim 1,
    Calculate in advance the relationship between any one or more of the pH, sulfurous acid concentration, alkalinity, and temperature of the sulfur-absorbing seawater and the dissolved oxygen concentration,
    The said dissolved oxygen concentration is calculated | required based on any one or more of pH, sulfurous acid concentration, alkalinity, and temperature of the said sulfur content absorption seawater calculated beforehand.
  3. 　請求項１または２において、
    　前記空気供給手段は、前記硫黄分吸収海水に前記空気を間隔をおきながら供給することを特徴とする酸化槽。     In claim 1 or 2,
    The said air supply means supplies the said air to the said sulfur content absorption seawater at intervals, The oxidation tank characterized by the above-mentioned.
  4. 　請求項１乃至３の何れか１つにおいて、
    　前記空気供給手段は、前記硫黄分吸収海水の溶存酸素濃度が所定値以下となった時に供給することを特徴とする酸化槽。     In any one of Claims 1 thru | or 3,
    The said air supply means supplies when the dissolved oxygen concentration of the said sulfur content absorption seawater becomes below a predetermined value, The oxidation tank characterized by the above-mentioned.
  5. 　排ガスと海水とを気液接触して前記排ガスを洗浄する排煙脱硫吸収塔と、
    　前記排煙脱硫吸収塔の後流側に設けられ、請求項１乃至４の何れか１つに記載の酸化槽と、
    　前記海水を前記排煙脱硫吸収塔に供給する海水供給ラインと、
    　前記排煙脱硫吸収塔から排出される前記硫黄分吸収海水を前記酸化槽に供給する硫黄分吸収海水排出ラインと、
    　前記海水を前記硫黄分吸収海水排出ラインと前記酸化槽との何れか一方または両方に供給する希釈海水供給ラインと、
    を有することを特徴とする海水排煙脱硫システム。     A flue gas desulfurization absorption tower that cleans the exhaust gas by gas-liquid contact between the exhaust gas and seawater;
    The oxidation tank according to any one of claims 1 to 4, provided on the downstream side of the flue gas desulfurization absorption tower,
    A seawater supply line for supplying the seawater to the flue gas desulfurization absorption tower;
    A sulfur-absorbing seawater discharge line for supplying the sulfur-absorbing seawater discharged from the flue gas desulfurization absorption tower to the oxidation tank;
    A diluted seawater supply line for supplying the seawater to one or both of the sulfur-absorbing seawater discharge line and the oxidation tank;
    A seawater flue gas desulfurization system characterized by comprising:
  6. 　ボイラと、
    　前記ボイラから排出される排ガスを蒸気発生用の熱源として使用すると共に、発生した蒸気を用いて発電機を駆動する蒸気タービンと、
    　請求項５の海水排煙脱硫システムとを有し、
    　前記蒸気タービンで凝縮した水を回収し、循環させる復水器と、
    　前記ボイラから排出される排ガスの脱硝を行う排煙脱硝装置と、
    　前記排ガス中の煤塵を除去する集塵装置と、
    を有することを特徴とする発電システム。     With a boiler,
    Using the exhaust gas discharged from the boiler as a heat source for generating steam, and a steam turbine for driving a generator using the generated steam;
    A seawater flue gas desulfurization system according to claim 5;
    A condenser for collecting and circulating the water condensed in the steam turbine;
    A flue gas denitration device for denitrating exhaust gas discharged from the boiler;
    A dust collector for removing the dust in the exhaust gas;
    A power generation system comprising:
PCT/JP2013/051640 2012-01-31 2013-01-25 Oxidation tank, seawater flue-gas desulfurization system and power generation system WO2013115108A1 (en)

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