0001]The present invention relates to an exhaust gas treatment system.
BACKGROUND
[0002]For example, CO in the exhaust gas from the steel production process or the like 2 to CO 2 when recovered by the recovery facility, for example, drawn into the absorption column, in this absorption tower CO 2 by contacting the absorption liquid (hereinafter referred to as "absorbing solution") , CO in the exhaust gas 2 is taken up in the absorption solution, CO 2 technique for removing recovered is proposed. The CO 2 absorbing solution which has absorbed is fed to the regenerator, CO by heating with steam 2 to dissipate, high purity CO 2 is recovered.
[0003]
　Current CO 2 in the recovery facility, because huge steam consumption for absorbing solution regeneration, toward the reduction of the steam consumption, it is necessary to aim to further energy saving. Simultaneously, when the solid dust and the like contained in the exhaust gas in the absorbing liquid is accumulated, when separating removed by the solids from the absorption liquid e.g. reclaimer or the like, the absorbent adhering to the discharge solids and loss reduction, efficient solids removal from the absorbing liquid is an issue.
[0004]
　Therefore, as a technique for efficiently removed solids from the absorption solution, for example, a flocculant is added to the absorption liquid, by coarse flocculated fine metallic impurities in the absorbing liquid, solid separation efficiency of the filtration device techniques for improving has been proposed (Patent Document 1).
[0005]
　Further, using the configured filter heavy medium also specific gravity than the solids captured from the absorption liquid in those held in mesh, by sedimentation filtration from the mixed effluent solids and the filter medium after the filtration unit backwashing, recovery and reuse techniques have been proposed filter media (Patent Document 2).
CITATION
Patent Document
[0006]
Patent Document 1: JP-A-3-151015 JP
Patent Document 2: JP 2011-56399 JP
Summary of the Invention
Problems that the Invention is to Solve
[0007]
　However, in the technique of Patent Document 1, the removal of the absorbent and the discharged solids remain in sedimentation, reduced sorbent loss there is a problem that it is insufficient.
[0008]
　Further, in the technique of Patent Document 2, solids removal becomes waste, must be treated as a separate waste, there is a problem that increase its processing cost.
[0009]
　That is, in the state of the art, the reduction of the absorbent loss adhering to the discharge solids, although solids separated off improvement from the absorption liquid is carried out as a problem of the efficiency of the absorption liquid in the solids removal, removal costs for processing the rear solids as waste increase, there is a problem that.
[0010]
　Thus, for example, iron-based solid material and acid gas discharged from the reduction equipment such as steelmaking process (e.g. CO 2 , H 2 from the exhaust gas containing a S or the like), after collected ferrous solids collected solid things effectively utilizing the emergence of technologies to reduce the waste is desired.
[0011]
　In view of the above problems, the exhaust gas containing the iron-based solids is discharged and acid gas from the reduction equipment, after collecting the iron-based solid material, it is possible to effectively utilize the collected solids and to provide an exhaust gas treatment system.
Means for Solving the Problems
[0012]
　The first aspect of the present invention to solve the above problems, comprises the reduction facility to reduce processing iron oxide reduced iron, and at least an iron-based solid material and acid gas discharged from the reduction equipment gas from the acid gas recovery equipment for recovering the acid gas by the acid gas absorbing liquid, and a recovery facility collecting device for collecting the iron-based solid material contained in the acid gas absorbing liquid was collected in the collecting device the iron-based solids desorbed gas from the reduction equipment, characterized in that the recovery facility desorption containing the desorbed iron-based solid material and a separated matters return line back into the reduction equipment-side in the processing system.
[0013]
　The second invention according to the first invention, the collecting device is provided with an extraction line for extracting the acid gas absorbing liquid from the acid gas recovery facility, the filtrate after collecting the iron-based solid material, wherein lying in the exhaust gas treatment system of the reduction equipment, characterized in comprising: a filtrate supply line back to the acid gas recovery facility, the.
[0014]
　The third invention is the invention of the first or second acid gas recovery is provided before downstream equipment, circulating cooling water exhaust gases containing at least iron solids and acid gas discharged from the reduction equipment a cooling device for cooling by a collecting device for collecting the iron-based solid material contained in the circulating cooling water, a cooling tower desorption device for desorbing ferrous solids were collected by the collection device, exhaust gas treatment system of the reduction equipment, characterized in that and a separated matters return line back into the reduction equipment-side cooling towers desorption containing the cooling tower desorption desorbed iron-based solid material in the apparatus It is in.
[0015]
　A fourth invention, in the third invention, the cooling tower desorption apparatus, wherein a extraction line for extracting the cooling water from the cooling device, the filtrate after collecting the iron-based solid material, the cooling tower in the exhaust gas treatment system of the reduction equipment, characterized in that and a filtrate supply line back to.
[0016]
　A fifth invention, in any one invention of the first to fourth, wherein the collecting device comprises a filter, said filter, cartridge filter, precoat filter, metal slit filter, a wire mesh filter, sintered metal filters, magnetic in the exhaust gas treatment system of the reduction equipment, which is a any one or combination of filters.
[0017]
　According to a sixth aspect, in any one invention of the first to fourth, wherein the collecting device comprises a filter, said filter, cartridge filter, precoat filter, metal slit filter, a wire mesh filter, any sintered metal filter or it is one or a combination thereof, on the surface of the filter, provided with a filter medium, the filter medium is that the particles of iron-based compounds coated with a resin is deposited from reduction equipment, characterized in the exhaust gas treatment system.
[0018]
　According to a seventh invention, in any one invention of the first to fourth, wherein the collecting device comprises a filter, the filter is a magnetic filter, the surface of the magnetic filter, provided with a filter medium, wherein the filter medium is a iron compound particles having magnetism while being covered with the resin, upon application of a magnetic field, reducing equipment, wherein the iron-based compound particles are deposited on the surface of said magnetic filter the exhaust gas treatment system from one.
Effect of the invention
[0019]
　According to the present invention, by recycling the iron-based solid material is a high filter trapped material having utility in reducing equipment, it is possible to achieve a significant reduction of the amount of waste has been conventionally discarded. Further, the iron-based solid material, at the reduction equipment, it is possible to obtain reduced iron by again reducing treatment, it is possible to improve recycling efficiency.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020]
[1] Figure 1 is a schematic view of the exhaust gas treatment system from reducing facility according to Example 1.
FIG. 2 is a schematic view of the exhaust gas treatment system of the other reducing facility according to Example 1.
FIG. 3 is an explanatory view of a filtration mechanism to place the collecting device according to the present embodiment.
[4] FIG. 4 is an explanatory diagram of another filtration mechanism to place the collecting device according to the present embodiment.
FIG. 5 is, CO according to the second embodiment 2 is a schematic view of a recovery system.
[Figure 6-1] Figure 6-1 is a schematic view of the operation sequence of the recovery facility collecting apparatus according to the present embodiment.
[Figure 6-2] Figure 6-2 is a schematic view of the operation sequence of the recovery facility collecting apparatus according to the present embodiment.
[Figure 6-3] Figure 6-3 is a schematic view of the operation sequence of the recovery facility collecting apparatus according to the present embodiment.
[Figure 6-4] Figure 6-4 is a schematic view of the operation sequence of the recovery facility collecting apparatus according to the present embodiment.
[Figure 6-5] Figure 6-5 is a schematic view of the operation sequence of the recovery facility collecting apparatus according to the present embodiment.
[Figure 6-6] Figure 6-6 is a schematic view of the operation process of the filtration membrane apparatus according to the present embodiment.
DESCRIPTION OF THE INVENTION
[0021]
　With reference to the accompanying drawings, illustrating preferred embodiments of the present invention in detail. It is not intended the invention be limited by this example, also, if the embodiment there are a plurality, i.e., an constitute a combination of each embodiment.
Example 1
[0022]
　Figure 1 is a schematic view of the exhaust gas treatment system from reducing facility according to the present embodiment. As shown in FIG. 1, the exhaust gas processing system 10A according to the present embodiment, the addition of iron oxide (e.g., iron ore, etc.) 11 reducing agent 12, and reducing the equipment 14 to reduction treatment reduced iron 13, reduction facility 14 exhaust gas line L from 1 is discharged through the at least powdered iron-based solid material 15 and the acid gas (CO 2 ) and CO from the exhaust gas 16 containing an acidic gas absorbing liquid 2 absorbing solution (hereinafter "absorbing solution" CO is an acidic gas by that) 20 2 and the acid gas recovery equipment 21 to recover, and recovery equipment collecting device 31A for collecting ferrous solids 15 contained in the absorbent solution 20 by the filter, collecting facility collecting the iron-based solids 15 collected in apparatus 31A desorbed line L returns the first separated matters returning the separated matters 32A containing the desorbed iron-based solid material 15 in the reducing facility 14 side 4 and , it is those with a. In this embodiment, CO and acidified gas 2 will be described with reference to, the present invention is not limited thereto, for example, H 2 can also be applied to acidic gases such as S.
[0023]
　In this embodiment, recovery facility collecting device 31A is extraction line L withdrawing the absorption liquid 20 from the acid gas recovery equipment 21 2 and the filtrate 20A after collecting the iron-based solid material 15, an acid gas recovery filtrate supply line L to return to the facility 21 3 and is provided with a filtrate 20A is reused as the absorption liquid in the acid gas recovery equipment 21.
[0024]
　Evacuation line L withdrawn from the acid gas recovery equipment 21 2 iron-based solid material present in the absorbent solution 20 was withdrawn by 15 are separated by the recovery facility collecting device 31A having the collecting member such as a filter that. Then, CO in the system 2 for separating the iron-based solid material retained on the filter by washing the filter with absorbent low concentration waste water containing or wash water, and absorbent components to be attached. The separated sorbent components, CO 2 absorbent with low concentration waste water containing or wash water, filtered supply line L into the system of the acid gas recovery equipment 21 3 are recovered via.
[0025]
　Examples of the filter installed in the recovery facility collecting device 31A, but are not particularly limited as long as it collects the iron-based solids 15 contained in the absorbing liquid 20, for example a cartridge filter, precoat filter, metal slit filter, a wire mesh filter, sintered metal filter, is preferably either or combination of magnetic filter.
[0026]
　Here, filter for collecting ferrous solid 15 is installed in the recovery facility collecting device 31A. Then, as the desorbing means for desorbing the iron-based solids 15 from the filter, it can be mentioned, for example, scraper, backwash facilities by the gas. Further, prior to desorption, keep advance was partially dried are preferred.
[0027]
　On the other hand, the separated matters 32A to an iron-based solid material 15 trapped by the filter as a main component, the line L returns the first separated matters to reduction facility 14 ore 4 is recycled through.
[0028]
　According to this embodiment, by recycling iron-based solids 15 it is highly useful filter the collected matter in the reduction facility 14, it is possible to achieve a significant reduction of the amount of waste has been conventionally discarded. Further, iron-based solids, the reduction facility 14, it is possible to obtain a reduced iron 13 by again reducing treatment, it is possible to improve recycling efficiency.
[0029]
　Figure 2 is a schematic view of the exhaust gas treatment system of the other reducing facility according to the present embodiment. Figure, the exhaust gas treatment system 10A having the same configuration according to the first embodiment of the present invention shown in FIG. 1 and redundant description are denoted by the same reference numerals will be omitted. As shown in FIG. 2, the exhaust gas processing system 10B according to this embodiment, prior to downstream side of the acid gas recovery equipment 21, has established a cooling tower 19 for cooling the exhaust gas, cooling circulating the cooling tower 19 the water 18 is also, in the cooling tower collecting device 31B, similarly removed by a filter, cooling tower separated matters 32B containing iron-based solid material 15, the line L back second separated matters 7 iron ore through the so that recycled to the reduction facility 14. The cooling tower trap 31B is extraction line L from the cooling tower 19 is withdrawn cooling water 18 5 and, filtrate feed the filtrate 18A after collecting the iron-based solid material 15 back to the cooling tower 19 line L 6 includes a, a.
[0030]
　According to this embodiment, by recycling iron-based solids 15 is a filter trapped material highly useful contained in the coolant 18 circulating in the cooling tower 19 to the reduction facility 14, it has been conventionally discarded it is possible to achieve a significant reduction of waste. Further, iron-based solids, the reduction facility 14, it is possible to obtain a reduced iron 13 by again reducing treatment, it is possible to improve recycling efficiency.
[0031]
　Figure 3 is an explanatory view of a filtration mechanism to place the collecting device according to the present embodiment.
[0032]
　As shown in FIG. 3, in this embodiment, the filter 51, the particles of iron-based compounds, is deposited as a filter medium 52. The particles of iron-based compounds, for example iron oxide (Fe 2 O 3 , Fe 3 O 4 , Fe 2 O 3 · nH 2 O, FeO (OH), FeO etc.) and iron carbonate (FeCO 3 and the like) it can.
[0033]
　Particles of iron-based compound to be deposited on the filter 51 as a filter medium 52 is coated, for example, epoxy resin or the like. The particle size of the particles of iron-based compounds, have a larger than mesh of the filter 51, that is deposited on the filter surface by supplying particles to the filter 51 constitute a filter medium 52 of the filter layer .
[0034]
　By forming the filter medium 52 consisting of particles of iron-based compounds, it can be enhanced removal efficiency of solids in the filter 51. Further, by using an iron-based compound as a filter medium particles, even when recycled to the reduction facility 14 of iron ore, not the impurity reduction step, it is possible to reduce the amount of impurities entering into the reduction equipment 14.
[0035]
　Further, in this embodiment, the particles of iron-based compound is preferably coated with a coating material such as epoxy resin. By coating the surface of particles in an epoxy resin or the like, so as to prevent the elution of iron ions from the filter medium 52 into the absorption liquid 20 in the filter portion of the recovery system collecting device 31A. Which, if present is iron ions in the absorption liquid, promote the oxidation of the absorbent to be incorporated into the absorption liquid, the absorption capacity of acid gases is reduced, in order to avoid this.
[0036]
　Examples of the coating agent, the use of thermally decomposed material at a high temperature such as an epoxy resin, without separating the absorbing liquid iron-based solid material 15 was present in 20 and filter media particles, iron ore it can be recycled as it is as a raw material to the reduction facility 14.
[0037]
　The temperature of the coating material of the epoxy resin, at least the process temperature of the acid gas recovery equipment 21, and for example, the following reduction treatment temperature in a reducing facility 14 of iron ore, preferably in the range of 200 ~ 300 ° C..
[0038]
　Figure 4 is an explanatory diagram of another filtration mechanism to place the collecting device according to the present embodiment. As shown in FIG. 4, in this embodiment, as the filter 55, using a magnetic filter, a magnetic field is applied, the particles 56a of an iron compound is deposited by depositing a magnetic filter medium 56 magnetized ing. Particles 56a of an iron compound having a magnetism, and coated with resin such as the as well as, for example, epoxy resin described above, to prevent the elution of iron ions.
[0039]
　As shown in FIG. 4, to supply particles 56a having magnetic on the surface of the magnetic filter 55 a magnetic field is applied to deposit a magnetic filter medium 56. When supplying the particles, since a magnetic field is formed, the particles 56a of an iron-based compound, even when a smaller particles than mesh of the magnetic filter 55, the magnetic filter medium 56 is formed, in Fig. 3 filter layer than can be improved trapping efficiency becomes dense.
[0040]
　When the filtering process the absorption liquid 20 is allowed to magnetize the magnetic filter 55 and the magnetic filter medium 56 while applying a magnetic field. Then, the absorbing liquid 20 containing an iron-based solid 15 was filtered process, when passing through the filter medium 56 which absorbs liquid 20 is magnetized, when the iron-based solid material 15 has magnetism, the filter medium 56 It is collected by a magnetic force. Further, the iron-based solid material 15 in each case having no magnetism, are collected by colliding with the magnetic filter medium 56 which is formed densely. After filtration process is completed, stop the application of a magnetic field, the magnetization of the filter to dissipate causes the filter medium 56 iron-based solid material 15 has been collected from the magnetic filter 55 eliminated.
[0041]
　According to this embodiment, by the operation of applying a magnetic field to the filter, the filter medium for collecting the iron-based solid material 15 can be formed densely, improvement of the collection amount of the iron-based solid material 15 it can be achieved. Further, by the operation of the application of a magnetic field facilitates attachment and detachment of the magnetic filter 55 and filter medium 56.
Example 2
[0042]
　In this embodiment, carbon dioxide (CO as acid gases 2 illustrate), the carbon dioxide recovery unit as acid gas recovery equipment (hereinafter "CO 2 will be described below with reference to that recovery unit"). 5, CO according to the second embodiment 2 is a schematic view of a recovery system. As shown in FIG. 5, CO according to Example 2 2 recovery system 1000 includes a reduction facility 14 for reduction treatment iron oxide (e.g., iron ore) 11 to reduced iron, iron-based solid material which is discharged from the reduction facility 14 15 and CO 2 and the exhaust gas 16 and CO containing 2 contacting the absorbing solution 1005 CO 2 CO removing 2 and absorption tower (hereinafter referred to as "absorption tower") 1004, CO 2 rich solution 1005A which has absorbed CO by the heat exchange of the vapor from the reboiler 1020 2 and the absorbent regenerator (hereinafter referred to as "regeneration tower") 1006 to play dissipate, with withdrawal of the rich solution 1005A from the absorption tower 1004, introduced to the regenerator 1006 side to the rich solution supply line L 11 and, CO reproduced by the regeneration tower 1006 2The lean solution 1005B but which is dissipated, with withdrawn from the regeneration tower 1006, the lean solution supply line L by introducing lean solution 1005B reused in the absorption tower 1004 in the absorption tower 1004 12 and the lean solution supply line L 12 from branch branch fluid line L 21 is interposed, and a recovery facility collecting device 31A for collecting the iron-based solids 15 contained in the lean solution 1005B-1 that branches filter 51, collecting facility collecting device the filtrate 1005B-2, which has passed through the 31A lean solution supply line L 12 filtrate supply line L to return to 22 and a desorption device for desorbing iron-based solid material 15 that is collected by collection equipment collecting device 31A, line L back separated matters returning separated matters 32A including iron-based solids 15 detached with desorber to reduction facility 14 side 4 and one in which comprises a.
[0043]
　In this embodiment, cooling tower 1030 for cooling the flue gas 16 is installed in the upstream side of the absorption tower 1004, to cool the flue gas 16 by using cooling water 1031 to circulate to a predetermined temperature prior to introduction into the absorption tower 1004 there.
[0044]
　Further, to the regenerator 1006, CO accompanied the released steam from the top 1006a of the absorbent regenerator 1006 2 condenses the water vapor in the discharged gas 1007 containing gas as condensed water 1028, separating condensed water 1028 It provided with a separation drum 1026 to. Moreover, the absorption tower 1004, CO 2 gas and CO containing 2 contacting the absorbing solution 1005 CO in the flue gas 16 2 CO absorbs 2 and the recovery unit 1010, the CO 2 in the upper side of the recovery unit 1010 is arranged, CO 2 CO removing the 2 to cool the flue gas 16A, entrained CO 2 and water washing section 1013 for collecting the washing water 1013a liquid absorbent is disposed on the lower side of the washing unit 1013, washing and a condensed-water receiver 1015a to collect condensed water 1014 generated in parts inside 1013. Washing water 1013a used by the water washing section 1013, the condensed water supplying line L a portion of the condensed water 1028 separated by the separation drum 1026 24 are supplied by. Incidentally, CO with washing water 1013a 2 purifying exhaust gas 16B removing the absorbing liquid is discharged to the outside from the top of the absorption tower 1004.
[0045]
　In the present embodiment, as washing water 1013b to clean the filter 51, CO was recovered in the condensate receiver 1015a 2 uses a portion of the condensed water 1014 containing absorbing solution 1005, the cleaning water supply line L 15 It is to be supplied to the recovery facility collecting device 31A through the.
[0046]
　The CO 2 recovery system 1000 CO using a 2 in the recovery process, in an absorber 1004, CO 2 containing exhaust gas 16, CO provided on the lower side of the absorption tower 1004 2 nozzles in the recovery unit 1010, a liquid distributor 1011 CO supplied from 2 countercurrent contact with absorption liquid 1005, CO 2 CO in exhaust gas containing 16 2 , for example, chemical reaction (2R-NH 2 + CO 2 → R-NH 3 + + R-NH-COO - , R-NH 2 + H 2 O + CO 2 → R-NH 3 + + HCO 3 - ) by CO 2 is absorbed in the absorbing solution 1005.　
[0047]
　Then, CO 2 CO after was removed 2 flue gas 16A is, CO is supplied from the nozzle 1011 in the washing section 1013 2 contacts the cleaning water 1013a and gas-liquid containing absorbing solution 1005, CO 2 in the flue gas 16A entrained CO 2 absorbing solution 1005 is collected. Further, CO was recovered in the condensate receiver 1015a 2 condensed water 1014 containing absorbing solution 1005, the liquid circulation line L 14 is fed through and is reused as cleaning water washing section 1013.
[0048]
　Furthermore, CO is withdrawn from the bottom of the absorption tower 1004 2 CO which has been absorbed 2 concentration is high rich solution 1005A is rich solution supply line L 11 rich solvent pump P through a 1 at the feed to the regenerator 1006 side is, is introduced from the top 1006a vicinity of the regenerator 1006 in the column, when flowing down the column, caused an endothermic reaction by indirectly heated steam by saturated steam 1021 in reboiler 1020, most of the CO 2 was released and regenerated. Incidentally, the saturated steam 1021 is discharged from the reboiler 1020 as condensed water 1022.
[0049]
　Further, from the top of 1006a of the absorbing solution regeneration tower 1006, the released gas 1007 with steam released from the rich solution 1005A is derived in the tower. The released gas 1007 with steam is water vapor is condensed by the cooling section 1025, water is separated as condensate 1028 in the separation drum 1026, CO 2 only gas is recovered is discharged out of the system. Condensed water 1028 separated in the separation drum 1026 is supplied to the upper or the like of the upper and the absorption tower 1004 of the absorbing solution regeneration tower 1006, and adjust the water balance in the closed system.
[0050]
　The regeneration tower 1006 CO reproduced by 2 concentration is low lean solution 1005B is cooled is replaced rich solution 1005A and the heat in the heat exchanger 1016, a lean solvent pump P followed 2 is boosted by further lean solvent after being cooled by the cooler is fed to the absorption tower 1004 again, CO 2 is circulated reused as absorbing solution 1005.
[0051]
　In this embodiment, such CO 2 when performing the recovery, if there is improvement in the concentration of the iron-based solid material 15 in the lean solution 1005B, introducing lean solution 1005B to recovery facilities collecting device 31A, the filter by collecting the iron-based solid material 15 remaining in the lean solution 1005B-1 at 51, the lean solution 1005B-2 iron-based solid material 15 has been removed the lean solution supply line L 12 can be supplied to the .
[0052]
　Thus, CO circulates the absorption tower 1004 and the regenerator 1006 2 so that reduce the solids concentration in the absorbing solution 1005.
[0053]
　Then, the recovery facility collecting device 31A, after the recovery facility separated matters 32A in desorber not shown detached, the recovery system eliminated material 32A, the line L return separated matters 4 of iron ore through the It is recycled to the reduction facility 14.
[0054]
　It will now be described washing removal operation and filter 51 of the iron-based solid material 15 in the recovery facility collecting device 31A. Figure 6-1 to Figure 6-6 is a schematic view of the operation sequence of the recovery facility collecting apparatus according to the present embodiment. Usually, CO in the exhaust gas 16 2 CO absorbs removed 2 In operation of recovering, as shown in Figure 6-1, when circulating through the absorption tower 1004 and the regeneration tower 1006, the branch fluid line L 21 valve V interposed 11 , filtrate supply line L 22 valve V interposed 12 with closing the lean solution supply line L 12 valve V interposed 13 by opening, closed system an inner, CO 2 circulating reused absorbing solution 1005 (lean solution 1005B).
[0055]
　In contrast, it is determined that the concentration of the iron-based solid material 15 in the lean solution 1005B becomes high, the operation in the case of removing the iron-based solid material 15 from the absorbent solution, as shown in Figure 6-2, when filtering a lean solution 1005B-1 in the recovery facility collecting device 31A, the valve V 11 , V 12 to open the. Thus, the lean solution supply line L 12 lean solution 1005B-1 was extracted partially from the branch fluid line L to the recovery facility collecting device 31A side feed the lean solution 1005B-1 Kyusuru 21 recovery equipment collecting via is fed into the device 31A, collecting the iron-based solid material 15 remaining in the lean solution 1005B-1 in filter 51 by the filter medium (not shown). The lean solution 1005B-2 is a filtrate iron-based solid material 15 has been removed, filtrate supply line L 22 lean solution supply line L through 12 are supplied to the.
[0056]
　Then, after the separation of the iron-based solid material 15 is completed, as shown in Figure 6-3, the cleaning water supply line L 15 valve V is interposed in 16 to release the, circulating in the system low concentration of CO 2 is supplied into the filtration apparatus main body 17 to absorb liquid as wash water 1013b. This supply of washing water 1013b, CO attached to the filter 51 2 to recover the absorbing solution 1005 in the wash water 1013b, to implement the rough cleaning of the filter 51.
[0057]
　In After this rough cleaning is completed, as shown in Figure 6-4, the cleaning water supply line L 15 valve V of 16 was closed, the cleaning water supply line L 23 valve V of 17 releases the, CO 2 absorption supplying washing water 25 containing no liquid 1005 to the recovery facility collecting device 31A. CO is supplied from the outside 2 the washing water 25 containing no absorbent solution, CO was attached to the filter 51 and the iron-based solids 15 2 implementing the final wash for cleaning and removing absorbing solution 1005. The finishing washing by implementing, in the rough cleaning can be removed the absorber component having adhered to the filter 51 and iron-based solid material 15 which can not be removed.
[0058]
　The final cleaning of CO was performed 2 finish washing water 25A containing the absorbing fluid return line L 22 lean solution supply line L through the 13 is supplied to and introduced into the absorption tower 1004.
[0059]
　In After the cleaning is completed, as shown in Figure 6-5, the valve V 11 , V 12 , V 16 and V 17 all closed, air line L to the recovery facility collecting device 31A 25 by air 28 the supplied from the same direction as in the case of washing with the wash water 25 to dry the filter 51.
[0060]
　After the drying is completed, as shown in Figure 6-6, the air 28 compressed backwash air line L from the opposite direction to the recovery facility collecting device 31A 26 and supplied by, blowing the filter medium of a filter, collecting as facilities elimination thereof 32A, desorption was return line L to the reduction facility 14 ore 4 is recycled through.
[0061]
　Results for introducing the final washing water 25A that this was a sorbent component desorbed absorption tower 1004, so so that the water from the outside is introduced, so that the amount of water in a closed system is increased. Therefore, in this embodiment, CO adjust the water balance in the absorption tower 1004 holds the water content in the system at a predetermined value, circulating in the system 2 operation to maintain the concentration of the absorbing solution 1005 to a predetermined concentration the may be conducted separately.
[0062]
　In this embodiment, CO circulates the absorption tower and the regeneration tower 2 has been explained that the removal of the iron-based solids contained in the absorbing solution 1005 is contained in the cooling water 18 circulating through the cooling tower 19 Iron was similarly removed the system solids 15 may be performed similarly to recycle the cooling tower separated matters to reduction facility 14.
DESCRIPTION OF SYMBOLS
[0063]
　10A, 10B the exhaust gas treatment system
　11 iron oxide (e.g., iron ore,
　etc.) 12 reducing agent
　13 reduced iron
　14 reduction facility
　15 iron-based solid material
　16 flue gas
　18 cooling water
　19 cooling tower
　20 absorbs liquid
　20A filtrate
　21 acid gas recovery equipment
　31A recovery facilities collecting device
　31B tower collecting device
　32A eliminated material
　32B cooling towers separated matters
　1004 absorption tower
　1005 CO 2 absorbing solution
　1005A rich solution
　1005B lean solution
　1006 absorbent regenerator
　1010 CO 2 recovery unit
　1030 cooling tower
　1031 coolant　

WE CLAIM

And reducing equipment for reduction treatment iron oxide reduced iron,
　from an exhaust gas containing at least iron solids and acid gases are discharged from the reduction equipment, acid gas recovery equipment for recovering the acid gas by the acid gas absorbing liquid When,
　a recovery facility collecting device for collecting the iron-based solid material contained in the acid gas absorbing liquid,
　the iron-based solids were collected by collecting device desorbed this desorbed ferrous solid exhaust gas treatment system of the reduction equipment, characterized in that and a return line eliminated material recovery facilities elimination thereof back into the reduction equipment side including the.
[Requested item 2]
　According to claim 1,
　wherein the collecting device comprises a discharge line for withdrawing the acid gas absorbing liquid from the acid gas recovery facility, the filtrate after collecting the iron-based solids, returned to the acid gas recovery equipment filtration exhaust gas treatment system of the reduction equipment, characterized in that it comprises a liquid supply line, the.
[Requested item 3]
　According to claim 1 or 2,
　provided on the upstream side of the acid gas recovery equipment,
　a cooling device for cooling the exhaust gas by the circulating cooling water containing at least iron solids and acid gas discharged from the reduction equipment,
　a collecting device for collecting the iron-based solid material contained in the circulating cooling water,
　the iron-based solid material which was collected by the collecting device and the cooling tower desorber for desorption
　in the cooling tower desorber exhaust gas treatment system of the reduction equipment, characterized in that it comprises a line cooling towers separated matters back eliminated material back into the reduction equipment side including the desorbed ferrous solids, the.
[Requested item 4]
　According to claim 3,
　wherein the cooling tower desorption apparatus, and an extraction line for extracting the cooling water from the cooling device, the filtrate after collecting the iron-based solid material, and filtrate supply line back to the cooling tower exhaust gas treatment system of the reduction equipment, characterized in that it comprises,.
[Requested item 5]
　In any one of claims 1 to 4,
　wherein the collecting device comprises a filter,
　one of said filter, cartridge filter, precoat filter, metal slit filter, a wire mesh filter, sintered metal filters, magnetic filters or the exhaust gas treatment system of the reduction equipment, which is a combination thereof.
[Requested item 6]
　In any one of claims 1 to 4,
　wherein the collecting device comprises a filter,
　said filter, cartridge filter, precoat filter, metal slit filter, a wire mesh filter, any one or a combination of sintered metal filter , and the
　on the surface of the filter, provided with a filter medium, the exhaust gas treatment system of the reduction facility the filter medium, characterized in that the particles of iron-based compounds coated with a resin is deposited.
[Requested item 7]
　In any one of claims 1 to 4,
　wherein the collecting device comprises a filter,
　the filter is a magnetic filter,
　the filter medium is provided on the surface of the magnetic filter,
　the filter medium is covered with a resin a iron-based compound particles having magnetism with being, when a magnetic field is applied, the exhaust gas treatment system of the reduction equipment, wherein the iron-based compound particles are deposited on the surface of the magnetic filter.