AU2013201118A1 - Fluidized bed drying apparatus, integrated gasification combined cycle system, drainage treating method, and lifetime determining method of activated carbon adsorption layer - Google Patents

Abstract

A fluidized bed drying apparatus is provided including: a fluidized bed drying devic; a crasher; a classifying unit; and a drainage treatment tank, wherein condensed water from the fluidized bed drying device is introduced into the drainage treatment tank, and is passed through the activated carbon adsorption layer that has been subjected to the biological treatment to be purified.

Description

FLUIDIZED BED DRYING APPARATUS, INTEGRATED GASIFICATION COMBINED CYCLE SYSTEM, DRAINAGE TREATING METHOD, AND LIFETIME DETERMINING METHOD OF ACTIVATED CARBON ADSORPTION LAYER BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluidized bed drying apparatus, an integrated gasification combined cycle system, a drainage treating method, and a lifetime determining method of an activated carbon adsorption layer which can be applied to a gasification system for gasifying carbonaceous fuel such as coal. 2. Description of the Related Art For example, an integrated coal gasification combined cycle gasifies coal in combination with combined cycle, and is a power generation apparatus which tries to achieve still higher efficiency and higher degree of environmental performance as compared a conventional coal-fired thermal power. This integrated coal gasification combined cycle apparatus is greatly advantageous in capable of using coal abundantly available, and it is known that, by enlarging the types of coals that can be used, still greater advantages can be obtained. In general, a conventional integrated coal gasification combined cycle apparatus includes a coaling device, a drying device, a gasification furnace, a gas purification device, a gas turbine apparatus, a steam turbine apparatus, a heat recovery steam generator, a gas purifying device, and the like. Accordingly, coal is dried and crushed, and is supplied to the gasification furnace as powdered coal, and at the same time, air is retrieved, and in this gasification furnace, the coal is made into 2 combustion gas, whereby produced gas (combustible gas) is generated. Then, this produced gas is purified, and then, the produced gas is provided to the gas turbine apparatus, and it is burned, so that high temperature and high pressure combustion gas is generated, which drives the turbine, thermal energy of the flue gas, which has driven the turbine, is recovered by the heat recovery steam generator, which generates steam which is provided to the steam turbine apparatus, so that the turbine is driven. Accordingly, electric power is generated. On the other hand, the flue gas of which heat is recovered by the heat recovery steam generator is provided to the gas purifying device where harmful substances are removed therefrom, and the flue gas is discharged to the atmosphere through a stack - By the way, the coal used in the integrated coal gasification combined cycle system (IGCC) may be not only high quality coal (high-grade coal) having a high degree of heat generation such as bituminous coal and anthracithe coal but also low-grade coal such as brown coal and subbituminous coal. The coal provided to the integrated coal gasification combined cycle system (IGCC) is required to be pulverized in view of the reactivity and airflow transport in the gasification furnace, and therefore, coal mill is used as the powdered coal device. For this reason, first, the coal provided as raw material is roughly crushed by a crusher, and thereafter, it is dried by a drier, and thereafter it is stored in a dried coal bunker. Subsequently, the coal providing device provides it to the coal mill, which crushes and dries the coal to make it into powdered coal, thereafter, it is carried with carrier gas, and is provided to the gasification furnace (Japanese Patent Application 3 Laid-open No. 7-279621). By the way, when the coal is fluidized and dried using steam when the drying device dries the coal, much condensed water of steam generated from wet material (of which moisture content is 60%) such as brown coal and much drain water from the drying device are generated, and, for example, organic acids and organic carbon components (COD components) are dissolved in the water thus generated, and as a result, pH is low which is p1H of about 3, and therefore separate drainage treatment is required. Coarse particles are generated from the drying device and the crasher which crushes raw coal fed into the drying device, and it is necessary for the crasher to crush the particles again. When foreign objects such as steel which is other than the brown coal included in the coarse particles are fed into the drying device as they are, the foreign objects may be stored in the apparatus system and may be concentrated, and it is strongly desired to do countermeasures of separation and removal thereof. SUMMARY OF THE INVENTION According to a first aspect of the present invention, there is provided a fluidized bed drying apparatus including: a fluidized bed drying device for receiving fluidized gas and causing wet material such as low-grade coal to flow so as to dry the wet material; a crasher provided at an upstream side of the fluidized bed drying device, for crushing the wet material into fine particles and coarse particles; a classifying unit for classifying part of the coarse particles from the crushed material and providing mixed particles including the fine particles and unclassified coarse particles to the fluidized bed drying 4 device; and a drainage treatment tank for receiving the coarse particles classified by the classifying unit and the coarse particles which are discharged from the fluidized bed drying device and which are included in the mixed particles, and provided with an absorption container having an activated carbon adsorption layer obtained by applying biological treatment, wherein condensed water from the fluidized bed drying device is introduced into the drainage treatment tank, and is passed through the activated carbon adsorption layer that has been subjected to the biological treatment to be purified. According to a second aspect of the present invention, there is provided a fluidized bed drying apparatus including.: a fluidized. bed drying device for receiving fluidized gas and causing wet material such as low-grade coal provided to a drying chamber to flow to dry the wet material to produce dried coal; a crasher provided at an upstream side of the fluidized bed drying device, for crushing the wet material into fine particles and coarse particles; a classifying unit for classifying part of coarse particles from the crushed material and providing mixed particles including the fine particles and unclassified coarse particles to the fluidized bed drying device; a gasification furnace for processing the dried coal provided from the fluidized bed drying device so as to change the dried coal into gasification gas; and a drainage treatment tank for extracting part of char included together with the gasification gas, receiving the extracted char, and provided with an absorption container having an activated carbon adsorption layer obtained by applying biological treatment, wherein condensed water from the fluidized bed drying device is introduced into the drainage treatment tank, and is passed through the activated carbon 5 adsorption layer that has been subjected to the biological treatment to be purified. According to a third aspect of the present invention, there is provided an integrated gasification combined cycle system including; the fluidized bed drying apparatus according to the first or second aspect; a gasification furnace for processing dried coal provided from the fluidized bed drying device so as to change the dried coal into gasification gas; a gas turbine for operating using the gasification gas as fuel; a steam turbine for operating with steam generated by a heat recovery steam generator receiving turbine flue gas from the gas turbine; and an electric power generator coupled with the gas turbine and/or the steam turbine. According to a fourth aspect of the present invention, there is provided a drainage treating method including: crushing wet material such as low-grade coal into coarse particles and fine particles; classifying part of coarse particles from the wet material; providing mixed particles including the fine particle and the coarse particles which are not classified in the classifying to a fluidized bed drying device; receiving fluidized gas and causing the mixed particles to flow to dry the mixed particles; dropping the coarse particles included in the mixed particles into a drainage treatment tank provided with an absorption container having an activated carbon adsorption layer obtained by applying biological treatment; and introducing condensed water from the fluidized bed drying device into the drainage treatment tank, and passing the condensed water through the activated carbon adsorption layer having been subjected to the biological treatment to purify the condensed water. According to a fifth aspect of the present invention, 6 there is provided a drainage treating method including: crushing wet material such as low-grade coal into coarse particles and fine particles; classifying part of coarse particles from the wet material; providing mixed particles including the fine particle and the coarse particles which are not classified in the classifying to a fluidized bed drying device; receiving fluidized gas and causing the mixed particles to flow to dry the mixed particles, thus generating dried coal; processing the dried coal provided from the fluidized bed drying device to change the dried coal into gasification gas; extracting part of the char included together with the gasification gas and dropping the extracted char into a drainage treatment tank provided with an .absorp.tiofn._.oqt.aiGer having an activated carbon adsorption layer obtained by applying biological treatment; and introducing the condensed water from the fluidized bed drying device into the drainage treatment tank, and passing the condensed water through the activated carbon adsorption layer having been subjected to the biological treatment to purify the condensed water. According to a six aspect of the present invention, there i.s provided a lifetime determining method of an activated carbon adsorption layer using the fluidized bed drying apparatus according to the first or second aspect, wherein a differential pressure gauge is provided to measure differential pressures before and after the activated carbon adsorption layer, and change of the differential pressure is monitored after a predetermined period of time passes, and, when a predetermined pressure setting value is attained, it is determined that a lifetime of the activated carbon treatment layer is reached. BRIEF DESCRIPTION OF THE DRAWINGS 7 FIG. 1 is a schematic view illustrating a fluidized bed drying apparatus according to a first embodiment; FIG. 2 is a schematic view illustrating steps of receiving separated coarse particles, performing biological treatment, and installation into a drainage treatment tank;. FIG. 3 is a schematic view illustrating the drainage treatment tank in which a monitoring unit for monitoring the degree of degradation is installed; FIG. 4 is a schematic view illustrating an example of differential pressure monitoring; FIG. 5 is a schematic view illustrating an example of differential pressure monitoring; FIG. 6 is a schematic view illustrating a fluidized bed._ ryin.g. apparats according to a second embodiment; FIG. 7 is a schematic view illustrating an example of a char extracting unit for extracting char from a char bin of a char recovery device; FIG. 8 is a schematic view illustrating another example of a drainage treatment tank; FIG. 9 is a view illustrating relationship of particle size distribution and accumulative rate (%) of char and crushed coarse particles of brown coal; and FIG. 10 is a schematic configuration diagram illustrating an integrated gasification combined cycle system according to the first embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention are made in view of the problems, and it is an object to provide a fluidized bed drying apparatus, an integrated gasification combined cycle system, a drainage treating method, and a lifetime determining method of an activated carbon adsorption layer capable of purifying the drainage condensed and generated 8 by the drying device and making raw coal coarse particles into finer particles. Hereinafter, preferred embodiments of fluidized bed drying devices according to the present invention will be explained in detail with reference to appended drawings. It is to be understood that the present invention is not limited by the embodiments, and when there are multiple embodiments, a configuration including a combination of embodiments may be included. [First embodiment] FIG. I is a schematic view illustrating the fluidized bed drying apparatus according to the first embodiment. .EIG......10..is a .schematic configuration diagram illustrating an integrated gasification combined cycle system according to the first embodiment. As illustrated in FIG. 10, an integrated gasification combined cycle (IGCC) system 10 according to the present embodiment employs air combustion method for generating coal gas in a gasification furnace using air as oxidizer, and generates electric power by providing coal gas purified by a gas purification device to a gas turbine apparatus as fuel gas. More specifically, the integrated coal gasification combined cycle of the present embodiment is electric power generation equipment of air combustion (air blown) method. In the present embodiment, low-grade coal of wet material is used as coal raw material provided to a gasification furnace 14. As illustrated in FIG. 10, in the present embodiment, an integrated gasification combined cycle system 10 includes a low-grade coal supply apparatus 11 providing wet material 101 providing wet material 101 which is original coal, a fluidized bed drying apparatus 12 according to the first embodiment and the second embodiment for drying the wet material 101, a gasification furnace 14 which provides dried coal 101C obtained by drying the wet material 101 and gasifies the dried coal 101C to produce gasification gas (combustible gas or produced gas) 200, a char recovery device 15 which recovers char 1OF in the gasification gas 200, a gas purification device 16 which purifies the gasification gas 200A obtained by recovering the char 101F, a gas turbine apparatus 12 which drives a turbine by burning fuel gas 200B purified, a steam turbine (ST) apparatus 18 operating with steam generated by a heat recovery steam generator (HRSG) 20 receiving turbine flue gas from the gas turbine apparatus 17, and an electric power.. gnerator..(. cpl with the gas turbine (GT) apparatus 17 and/or the steam turbine (ST) apparatus 18. The low-grade coal supply apparatus 11 according to the present embodiment includes a raw coal bunker 21, a raw coal supply device 22, and a crasher 23. The raw coal bunker 21 can store the wet material (low-grade coal) 101, and can drop a predetermined amount of wet material 101 into the raw coal supply device .22. The raw coal supply device 22 can convey the wet material 101 dropped by the raw coal bunker 21 with, for example, a conveyor, and can drop it into the crasher 23. This crasher 23 can crush the dropped wet material 101 into fine particles 101A and coarse particles 101B which are of predetermined sizes, thus making it into crushed coal. A fluidized bed drying device 102 uses the device according to the first or second embodiment to provide drying steam (for example, superheated steam of about 150 degrees Celsius) A to the fine particles 101A of the wet material 101 dropped by the low-grade coal supply apparatus 11, thereby heating and drying the this low-grade coal 10 while causing this low-grade coal to flow, and can remove moisture included in the fine particles 1OA of the wet material 101. This fluidized bed drying device 102 is provided with a cooling device 31 for cooling the dried coal 101C that has been dried and retrieved to the outside, and the dried and cooled dried coal 101C'is stored in a dried coal bunker 32. In addition, a dust recovery device 105 such as dried coal cyclone for separating particles of dried coal included together with a generated steam 104 retrieved from the top portion of the fluidized bed drying device 102 is provided to separate fine particles of dried coal from.the generated steam 104. The generated steam 104 from which dried coal is separated by the dust recovery evice 105 such as cyclone is compressed by the steam compression device 106 and provided, as drying steam A, to a heat transmission member 103 of the fluidized bed drying device 102. The dried and cooled dried coal 101C which has been dried in the main body of the drying chamber and then cooled by the cooling device 31 is temporarily stored to the dried coal bunker 32 by way -of a fine particle dried coal discharge line 123, and thereafter finely crushed by a powdered coal device 34 with a coal feeding device 33, and then, fine particles are removed by a powdered coal bug filter 35, and thereafter, stored by a powdered coal supply hopper 36. Depending on the degree of fineness of particles, the powdered coal device 34 may be omitted. The gasification furnace 14 can be provided with the dried coal 101C provided by the powdered coal supply hopper 36, and is provided with char (unburned coal) 101F recovered by the char recovery device 15, thus enabling 1~1 recycling. More specifically, the gasification furnace 14 is connected to a compressed air providing line 41 connected from the gas turbine apparatus 17 (compression device 61), so that compressed air compressed by this gas turbine apparatus 17 can be provided thereto. An air separation device 42 separates and generates nitrogen (N 2 ) and oxygen (02) from air 40 in the atmosphere, and a first nitrogen providing line 43 is connected to the gasification furnace 14, and this first nitrogen providing line 43 is connected to a fine particle dried coal discharge/feeding line 123. A second nitrogen providing line 45 is also connected to the gasification furnace 14, and this second nitrogen providing line 45..is connected to a char returning _line. 46 for returning the char 101F recovered from the char recovery device 15. Further, an oxygen providing line 47 is connected to the compressed air providing line 41. In this case, nitrogen (N 2 ) is used as carrier gas for the dried coal 101C and the char 101F, and oxygen (02) is used as oxidizer. The gasification furnace 14 is, for example, entrained bed- gasification furnace. The gasification furnace 14 burns and gasifies the dried coal 101C, the char 101F, air (oxygen), or steam as gasifying agent provided therein, and combustible gas (produced gas, coal gas) 200 is generated of which main component is carbon monoxide, and gasification reaction occurs using this combustible gas 200 as the gasifying agent. The gasification furnace -14 is provided with a foreign object removing device 48 for removing foreign -objects such as molten slag in the powdered coal. In this example, the entrained bed gasification furnace is illustrated as an example of the gasification 12 furnace 14, but the present invention is not limited thereto. For example, fluid bed gasification furnace and fixed bed gasification furnace may be employed. Then, this gasification furnace 14 is provided with a gas generation line 45 for the gasification gas 200 to the char recovery device 15, and is capable of discharging the combustible gas 200 including the char 101F. In this case, preferably, the gas generation line 49 is.provided with a gas cooling device, so that the gasification gas 200 is cooled to a predetermined temperature and is then provided to the char recovery device 15. The char recovery device 15 includes dust recovery devices 51, 54, a char bin 52, and a char supply hopper 53. In..thiccasa,. the dust.recovery devices 51 5Ainclude multiple bag filters and cyclones, and can separate the char 101F included in the combustible gas 200 generated by the gasification furnace 14. Then, the combustible gas 200A from which the char 101F is separated is conveyed via a gas discharge line 55 to the gas purification device 16. The char supply hopper 53 stores the char 101F, which is separated from the combustible gas 200 by the dust recovery device 51, by way of the char bin 52. The char returning line 46 connected from the char supply hopper 53 is connected to the second nitrogen providing line 45 in which carrier nitrogen (N2) is supplied. The gas purification device 16 performs gas purification by removing impurities such as sulfur compounds and nitrogen compounds from the combustible gas 200A from which char 101F is separated by the char recovery device 15. The gas purification device 16 produces the fuel gas 2005 by purifying the combustible gas 200A from which char 101F is separated, and provides this to the gas turbine apparatus 17, Since the combustible gas 200A from 13 which char 101F is separated still includes sulfur component (I 2 S), the gas purification device 16 removes it with, e.g., amine absorption liquid, so that the sulfur component is ultimately recovered as gypsum which is effectively made use of. The gas turbine apparatus 17 includes a compression device 61, a combustion chamber 62, and a turbine 63, and the compression device -61 and the turbine 63 are connected by a rotation shaft 64. The combustion chamber 62 is connected to a compressed air providing line 65 connected from the compression device 61, and is connected to a fuel gas providing line 66 connected from the gas purification device 16, and the combustion chamber 62 is connected to a combustion.gas providing.line 67 connected to the turbine 63. The gas turbine apparatus 17 is provided with the compressed air providing line 41 extending from the compression device 61 to the gasification furnace 14, and the compressed air providing line 41 has a pressurization device 68 is interposed in the compressed air providing line 41. Therefore, the combustion chamber 62 mixes and burns the fuel gas 200B provided from the gas purification device 16 with a compressed air 40A provided from the compression device 61, and the turbine 63 rotates the rotation shaft 64 using a generated combustion gas 212, and therefore, the combustion chamber 62 can drive the electric power generator 19. The steam turbine apparatus 18 has a turbine 69 coupled with the rotation shaft 64 of the gas turbine apparatus 17, and the electric power generator 19 is connected to a proximal end of this rotation shaft 64. The heat recovery steam generator 20 is provided in a flue gas line 70 connected from the gas turbine apparatus 17 (turbine 63), and generates steam 214 by exchanging heat 14 between air 40 and high temperature flue gas 213- For this reason, the heat recovery steam generator 20 is provided with a steam providing line 71 which provides steam 214 and which is arranged between the heat recovery steam generator 20 and the turbine 69 of the steam turbine apparatus 18. The heat recovery steam generator 20 is also provided with a steam recovering line 72, and a condensing device 73 is provided in the steam recovering line 72. Therefore, in the steam turbine apparatus 18, the turbine 69 is driven by the steam 214 provided from the heat recovery steam generator 20, and by rotating the rotation shaft 64, the electric power generator 19 can be driven. . Further, the flue gas 215- of which heat is recovered by the heat recovery steam generator 20 is provided to a gas purifying device 74 where harmful substances are removed therefrom, and the purified flue gas 215 is discharged to the atmosphere through a stack 75. Now, operation of the integrated gasification combined cycle system 10 of the present embodiment will be explained, The integrated gasification combined cycle system 10 of the present embodiment is configured such that, in the low-grade coal supply apparatus 11, the wet material 101 which is raw coal is stored in the raw coal bunker 21, and the wet material 101 in this raw coal bunker 21 is dropped by the raw coal supply device 22 into the crasher 23; which crushes it into a predetermined size. Then, the fine particles 101A which have been crashed and classified are heated and dried by the fluidized bed drying device 102, this dried coal 1OIC thus dried is extracted by the fine particle dried coal discharge line 123, and thereafter, it is cooled by the cooling device 31 to be made into cooled dried coal 101C of fine particles, which is stored in the dried coal bunker 32. Thereafter, the powdered coal device 15 34 pulverizes the coal, and the coal is stored in the powdered coal supply hopper 36. The dried coal 1OIC of fine particles stored in the powdered coal supply hopper 36 is provided to the gasification furnace 14 through the fine particle dried coal discharge line 123 with nitrogen provided from the air separation device 42. The char 101F recovered by the char recovery device 15 explained later is provided to the gasification furnace 14 via the char returning line 46 with nitrogen provided from the air separation device 42. Further, after a compressed air .37 bled from the gas turbine apparatus 17 explained later is pressurized by the pressurization device 68, it is provided via the compressed air providing line 41 to the gasificat-ion furnace 14 together with oxygen provided from the air separation device 42. The gasification furnace 14 burns the dried coal 1OIC, and the char 101F thus provided using compressed air (oxygen) 37 to gasify the dried coal 101C and the char 101F, thus producing combustible gas (coal gas) 200 main component of which is carbon monoxide. Then, this combustible gas 200.is discharged. from the gasification furnace 14 via the gas generation line 49, and is sent to the char recovery device 15. In this char recovery device 15, first, the gasification gas 200 is provided to the dust recovery device 51, and the dust recovery device 51 separates the char 101F included in the combustible gas 200. Then, the combustible gas 200A from which the char 101F is separated is conveyed via the gas discharge line 55 to the gas purification device 16- On the other hand, fine particle char 101F separated from the combustible gas 200 is stacked on the char supply hopper 53, and is returned via the char 16 returning line 46 back to the gasification furnace.14 to be recycled. The gas purification device 16 performs gas purification by removing impurities such as sulfur compounds and nitrogen compounds from the combustible gas 200A from which char 101F is separated by the char recovery device 15, so that fuel gas 200B is produced. Then, in the gas turbine apparatus 17, when the compression device 61 produces compressed air 40A and provides the air to the combustion chamber 62, this combustion chamber 62 mixes and burns the compressedair 40A provided by the compression device 61 and the fuel gas 200B provided from the gas purification device 16, thus producing combustion gas 212, and by driving the turbine 63 with this combustion gas 212, the electric power generator 19 is driven via the rotation shaft 64, and electric power can be generated. Then, the flue gas 213 discharged from the turbine 63 of the gas turbine apparatus 17 is subjected to heat exchange with air 40 in the heat recovery steam generator 20, whereby steam 214 is generated, and this generated steam 214 is provided to the steam turbine apparatus 18. In the steam turbine apparatus 1B, the turbine 69 is driven by the steam 214 provided from the heat recovery steam generator 20, and by rotating the rotation shaft 64, the electric power generator 19 is driven, and electric power can be generated. Thereafter, in the gas purifying device 74, harmful substances are removed from the flue gas 215 discharged from the heat recovery steam generator 20, and a purified flue gas 21A is discharged to the atmosphere through the stack 75. Hereinafter, the fluidized bed drying apparatus 12 in the integrated gasification combined cycle system 10 17 explained above will be explained in detail. As illustrated in FIG. 1, a fluidized bed drying apparatus 12A according to the present embodiment includes a fluidized bed drying device 102 receiving a fluidized gas 107 and causing the wet material 101 such as low-grade coal provided to a drying chamber 102a to flow to dry the wet material 101, a crasher 23 provided at the upstream side of the fluidized bed drying device 102 and crushing the wet material 101 into fine particles 101A and coarse particles 101B, a classifying unit 110 classifying some of coarse particles 101B from the crushed material and providing mixed particles including the fine particles 101A and unclassified coarse particles 101D to the fluidized bed drying device 102,-a drainage treatment tank 203 receiving the coarse particles 101B classified by the classifying unit 110 and the coarse particles 101D discharged from the fluidized bed drying device 102 included in the mixed particles and provided with an absorption container 202A having an activated carbon adsorption layer 201A obtained by applying biological treatment, wherein condensed water

B

1 , B 2 from the fluidized bed drying device 102 is introduced into the drainage treatment tank 203, and is passed through the activated carbon adsorption layer 201A that has been subjected to the biological treatment to be purified, and made into purified water 204. In FIG. 1, symbol F denotes freeboard, symbol S denotes a fluidized ,bed, and numeral 108 denotes a wind box providing the fluidized gas. In the fluidized bed drying device 102, the fine particles 101A classified by the classifying unit 110 are dropped via the fine particle providing line Li, and the fluidized bed S is formed together with the fluidized gas 107 provided to the wind box 108 .at the lower portion of 18 the main body of the drying chamber, and the fine particles 101A are dried by the heat transmission member 103 inserted into the fluidized bed S. The dried coal 101C that has been dried therein is discharged from the dried coal discharge line Lii to the outside. For example, the classifying unit 110 for classifying the crushed coal may be a publicly known particle classifying unit such as wind classifier and sieve classifier. In the present embodiment, the fine particles 101A are those of, for example, 2 mm or less, and the coarse particles 101B including foreign objects of 2 mm or more are provided into the absorption container 202A via a coarse particle providing line L2 and a combined line L 16 (*1). In the present embodiment, the fluidized steam 107 forming the fluidized bed S is discharged from the fluidized bed drying device 102, and a portion of the generated steam 104 from which dust has been recovered by the dust recovery device 105 is sent into the main body of the drying chamber by, for example, a circulation fan 109 interposed in the fluidized gas providing line L 12 . In the present embodiment, a portion of the generated steam 104 is reused as a fluidized medium for fluidizing the fluidized bed S, but the present embodiment is not limited thereto. For example, nitrogen, carbon dioxide or air of low oxygen concentration including these gases may be used. The heat transmission member 103 is provided in the fluidized bed S. For example, drying steam (superheated steam) A of 150 degrees Celsius is provided into the heat transmission member 103, and using the latent heat of high temperature drying steam (superheated steam) A, the fine 19 particle 101A in wet state is dried indirectly. In the present embodiment, a portion of the generated steam 104 from which dust has been recovered by the dust recovery device 105 is compressed by a latent heat recovering apparatus 106 having, for example, a compression device interposed in the steam providing line Li 3 , and is provided as the drying steam A to the heat transmission member 103. The drying steam (superheated steam) A used for drying process is discharged to the *outside -of the main body of the drying chamber as the condensed water B of 150 degrees Celsius, for example. Alternatively, a portion of drying steam (superheated steam) A may be compensated from the outside More specifically, on the inner surface of the heat transmission member 103 which is a heating unit, the drying steam (superheated steam) A is condensed and made into liquid (moisture), and therefore, the condensed latent heat radiated at this occasion is effectively used for heating for drying the fine particles 101A in wet state. In addition to high-temperature drying steam (superheated steam) A, any heat medium capable of phase change may be employed. For example, freon, pentane, and ammonia may be employed as an example. The heat transmission member may be not only the use of heat medium but also installation of electric heater. In the present embodiment, a heat transmission member in a tube shape is illustrated as an example of the heat transmission member 103 explained above, but the present invention is not limited thereto. For example, a plate shaped heat transmission member may be used. In this explanation, the drying steam (superheated steam) A is provided to the heat transmission member 103, and the fine particle 101A in wet state is dried indirectly, 20 but the present invention is not limited thereto. For example, the fine particles 101A in wet state may be dried directly with the fluidized steam 107 for causing the fluidized bed S of the fine particles 101A in wet state to flow, or heating fluidized gas may be provided to dry the fine particles 101A. In the present embodiment, the coarse particles 101D separated from the fluidized bed drying device 102 are provided via the coarse particle discharge line T 15 and the combined line L1E to the absorption container 202A. FIG. 2 is a schematic view illustrating steps of receiving separated coarse particles, performing biological treatment, and installation into a drainage treatment tank. As illustrated in FIG. 2, a predetermined amount of coarse particles (*1) 101B, 101D are filled into the absorption container 202A. Subsequently, biological treatment is applied using microorganisms 220, and the activated carbon adsorption layer 201A is formed in the absorption container 202A. It should be noted that the bottom portion of the absorption container 202A is a mesh 202a which passes water. In order to breed microorganisms, activated sludge for sewage treatment and drainage treatment may be used. The absorption container 202A filled with the activated carbon adsorption layer 201A formed by the biological treatment is installed on a stand 203b formed in a passage of the first drainage treatment tank 203A by way of an opening portion 203a. In this biological treatment, an apparatus for forming the activated carbon adsorption layer 201A obtained by breeding microorganisms in advance is installed at all times, and when it is time to replace the activated carbon adsorption layer 201A of the first drainage treatment tank 21 203A, the absorption container 202A having the activated carbon adsorption layer 201A is drawn out as a cartridge,. and, for example, using a heavy machinery such as a crane, it is installed into the first drainage treatment tank 203A. Then, the absorption container 202A having the activated carbon adsorption layer 201A to which the biological treatment is applied is installed in a portion of drainage passage in the first drainage treatment tank 203A. Then-, the condensed water B 1 , B2 are provided to the first drainage treatment tank 203A as "water to be treated, and by passing the water through the activated carbon adsorption layer 201A, organic acid components (for example, formic acid, acetic acid) and fine particles included at the side of the condensed water are moved to the side of the coarse particles, and are absorbed in the coarse particles 101B, 101D which are biologically treated- As a result, organic acids and the like are removed from the condensed water B 1 , B 2 The purified water 204 having passed the first drainage treatment tank 203A does not include any organic acid or organic carbon component (COD component) in the moisture, and therefore, for example, the purified water 204 having passed the first drainage treatment tank 203A can be used as makeup water such as general-purpose cooling wate and industrial water. When used for a predetermined period of time, the activated carbon adsorption layer 201A that absorbs and removes the organic acids and the like from the condensed -water B 1 , B2 is degraded, and is therefore replaced. FIG. 3 is a schematic view illustrating the drainage treatment tank in which a monitoring unit for monitoring the degree of degradation is installed.

22 As illustrated in FIG. 3, a differential pressure gauge 205 for measuring a differential pressure before and after the activated carbon adsorption layer 201A is provided. Then, change of the differential pressure after a predetermined period of time is monitored, and when a setting value is attained, it is determined that the lifetime of the activated carbon adsorption layer 201A is reached, and the activated carbon adsorption layer 201A is replaced. FIG. 4 is a schematic view illustrating an example of differential pressure monitoring. As illustrated in FIG. 4, when the drainage treatment is performed, and the differential pressure is monitored with the differential pressure gauge..205 on every predetermined period of time, and when the setting value is almost attained, the lifetime (approximate lifetime) is determined to be reached, and the absorption container 202A is replaced with an absorption container 202A having a new activated carbon adsorption layer. It should be noted that the setting value is obtained in advance at which operation is difficult. In addition to the method of measurement with the differential pressure gauge, degradation may be determined based on the change of pH of treatment water. As illustrated in FIG. 3, a pH meter 207 is provided in the discharge line 206 for the purified water 204 connected from the first drainage treatment tank 203A in order to measure pH of the purified water 204. Then, change of pH after a predetermined period of time is monitored, and when a setting value is attained, it is determined that the lifetime of the activated carbon adsorption layer 201A is reached, and the activated carbon adsorption layer 201A is replaced.

23 FIG. 5 is a -schematic view illustrating an example of differential pressure monitoring. As illustrated in FIG. 5, when the drainage treatment is performed, and pH is monitored with the pH meter 207 on .every predetermined period of time, and when the lower limit pH value (for example, pH of 6.5) .of the setting - value is almost attained, the lifetime (approximate lifetime) is determined to be reached, and the absorption - container 202A is replaced with an absorption container . . 202A having. a new activated carbon adsorption layer. The - . criterion of pH in- FIG. 5 is merely an example, and it is riot limited thereto. As described above, the lifetime (cartridge replacement, time) of the-activated carbon adsorption. layer 201A is determined on the basis of any one of or both of the measured values of the differential pressure of the activated carbon adsorption layer and pH in the drainage. In this case, when a determination is made using the differential pressure gauge 205, the differential pressure gradually increases as the fine particles in the water to be treated are accumulated in the activated carbon adsorption layer, and therefore, it is necessary to replace the cartridge before a differential pressure at which continuation of operation can be determined to be difficult is reached. When the determination is made using the pH meter 207, and the effect of absorption with the activated carbon is reduced, pH decreases (returning back to the side of the condensed water), and it is beyond the range of the environment provision, and therefore, it is necessary to . replace the cartridge before that. Accordingly, the crushed material of the wet material 101 crushed by the crasher 23 is classified into the fine 24 particles 1OA and the coarse particles 101B by the classifying unit 110, and the classified fine particles 1OA are dried by the heat transmission member 103 inserted into the fluidized bed S formed in the fluidized bed drying device 102, and are discharged as the dried coal 101C. Predetermined amounts of classified coarse particles 101B and coarse particles 101D from the fluidized bed drying device 102 are filled into the absorption container 202A, and the biological treatment is applied to make the activated carbon adsorption layer 201A. The absorption container 202A formed with this activated carbon adsorption layer 201A is installed in the first drainage treatment tank 203A in a cartridge form, and the drainage treatment of the condensed water is performed. Then, when the condensed water passes through the activated carbon adsorption tank 201A, organic acids component and fine particle components included in the condensed water are moved to the coarse particles, and are absorbed by the coarse particles. As a result, organic acids and the like are removed from the condensed water BI,

B

2 , As a result, in the present, embodiment, no particles but the fine particles 101A of which sizes are equal to or less than a predetermined particle size are introduced into the fluidized bed drying device 102, and coarse particles of which particle sizes are large are not introduced which causes insufficient drying, and therefore, the efficiency of drying is improved. The classified coarse particles 101B and the coarse particles 101D discharged from the fluidized bed drying device 102 form the activated carbon adsorption layer 201A for purifying the condensed water B 1 , B2, and are installed in the first drainage treatment tank 203A, so that organic 25 acids and the like are moved from the condensed water to the coarse particles, and the condensed water B 1 , B 2 can be purified efficiently. As a result, installation of a separate, independent drainage treatment apparatus is omitted. Moreover, this eliminates the necessity of purchase of dedicated activated carbon for biological activated carbon treatment from the outside, and this can greatly reduce the cost of the drainage treatment. In addition, the purified water 204 can be reused as makeup water such as cooling water, and therefore, the amount of used makeup water separately supplied and the cost of the usage can be reduced, so that the efficiency of the system is improved. At the upstream side of the drainage treatment tank 203, for example, preprocessing unit of at least one of or both of an ozone treatment tank and a filtration treatment tank is installed, so that the condensed water B1, B 2 may be purified before the condensed water B 1 , B2 are introduced to the drainage treatment tank 203. [Second embodiment). FIG. 5 is a schematic view illustrating a fluidized bed drying apparatus according to the second embodiment. Members having the same functions as those of the above embodiment are denoted with the same reference numerals, and detailed description is omitted. As illustrated in FIG. 6, a fluidized bed drying apparatus 12B of the second embodiment uses a portion of the char 101F separated from the char recovering apparatus 15 as illustrated in FIG. 10 instead of the coarse particles used in the fluidized bed drying apparatus 12A of the first embodiment (*2).

26 As illustrated in FIG. 6, the fluidized bed drying apparatus 12B according to the present embodiment includes a fluidized bed drying device 102 receiving the fluidized gas 107 and causing the wet material 101 such as low-grade coal provided to the drying chamber 102a to flow to dry the wet material 101 to produce dried coal 101C, a crasher 23 provided at the upstream side of the fluidized bed drying device 102 and crushing the wet material 101 into fine particles 101A and coarse particles 101B, a classifying unit 110 classifying some of coarse particles 101B from the crushed material and providing mixed particles including the fine particles 101A and unclassified coarse particles 101D to the fluidized bed drying device 102, a gasification furnace 14 processing the dried coal 101C provided from the fluidized bed drying device 102 to change it into gasification gas 200, a drainage treatment tank 203 extracting some of the char included together with the gasification gas 200 and receiving the extracted char 101F and provided with an absorption container 202B having an activated carbon adsorption layer 201B obtained by applying biological treatment, wherein condensed water B, B2 from the fluidized bed drying device 102 is introduced into the drainage treatment tank 203, and passed through the activated.carbon adsorption layer 201B that has been subjected to the biological treatment to be purified, and made into purified water 204. FIG. 7 is a schematic view illustrating an example of a char extracting unit for extracting char from a char bin of a char recovery device. As illustrated in FIG. 7, a char extracting line 230 provided on the bottom portion of the char bin 52, an extracting hopper 231 which is an extracting unit interposed in the char extracting line 230, and a 27 recovering chamber 232 provided at the side of the bottom portion of the extracting hopper 231 are provided. In FIG. 7, V, and V 2 denote a bleeder valve. As illustrated in FIG. 7, the char extracting unit of the present embodiment extracts a portion of the char 101F from the bottom portion of the char bin 52, and separates char 11F and gas 234 using a filter 233 installed in the extracting hopper 231. Thereafter, the bleeder valve V 2 is operated, the char 101F is recovered in normal pressure state into the absorption container 2023 in the recovering chamber 232 from the extracting hopper 231. The gas 234 is subjected to combustion treatment by a separate flare unit. Alternatively, a char foreign object removing unit in an existing IGCC plant may be used without providing a separate extracting hopper 231. Like the coarse particles 101B, 101D explained above, the extracted char 101F is subjected to the biological treatment, and the activated carbon adsorption layer 201B is formed to make a second drainage treatment tank 203B. Then, the condensed water B 1 , B 2 are provided to the second drainage treatment tank 203B as

T

treatment water, and by passing theater through the activated carbon adsorption layer 201B, organic acid components (for example, formic acid, acetic acid) and fine particles included at the side of the condensed water are moved to the side of the coarse particles, and are absorbed in the char 101F which are biologically treated. As a result, organic acids and the like are removed from the condensed water B1, B2 The moisture having passed the second drainage treatment tank 203B does not include any organic acid or organic carbon component (COD component) in the moisture, and therefore, for example, it can be used, as the purified water 204, as makeup water such as general-purpose cooling 28 wate and industrial water.. FIG. B is a schematic view illustrating another example of a drainage treatment tank. As illustrated in FIG. 8, in a third drainage treatment tank 203C, an absorption container 202A of an activated carbon adsorption layer 201A including coarse particles 101B, 101D.and an absorption container 202B of an activated carbon adsorption layer 201B.including char 101F are installed continuously in the drainage treatment passage. FIG. 9 is a view illustrating relationship of particle size distribution and accumulative rate (%) -of char and crushed coarse particles of brown coal. As illustrated in FIG. 9, the particle size distribution of the char 101F and the brown coal *coarse particles 101B, 101D are such that the particle size. distribution of the char is in the range of 80 to 120 pm, and on the other hand, the width of the particle size distribution of the coarse particles are wider. Therefore, by making use of such difference in the particle sizes of the coarse brown coal and the char (coarse brown coal>char), multiple-step drainage treatment tank is made to further increase the efficiency of absorption. In the third drainage treatment tank 203C of the present embodiment, the activated carbon adsorption layer 201A absorbs relatively coarse particles with the brown coal layer at the upstream side, and the fine particles that could not be absorbed here are absorbed by the activated carbon adsorption layer. 202B with the char layer .at the downstream side. Accordingly, the load of absorption can be reduced, and the lifetime of the drainage treatment tank can be 29 improved. In this case, in the activated carbon adsorption layer used in the drainage treatment tank, the coarse particles may be provided to the crasher 23 or the fluidized bed drying device 102 again and dried by the fluidized bed drying device 102, and provided to the gasification furnace. - The char may be dried by the fluidized bed drying device 102, and provided to the gasification furnace. A predetermined rate of char may be mixed in the activated carbon absorption layer 201A formed with the coarse particles 101B, 101D of the first drainage treatment tank 203A of FIG. 1, and a mixed layer may be made. According to a fluidized bed drying device of the present invention, only fine particles of which sizes are equal to or less than a predetermined particle size are introduced into the fluidized bed drying device by the classifying device, and therefore, the efficiency of drying is improved. The classified coarse particle, the coarse particles discharged from the fluidized bed drying device, or the char from the gasification furnace is used to form the activated carbon adsorption layer, with which the condensed water which is the drainage, from the fluidized bed drying device is purified, and therefore, installation of a separate, independent drainage treatment apparatus using activated carbon can be omitted.

Claims (14)

1. A fluidized bed drying apparatus comprising: a fluidized bed drying device for receiving fluidized gas and causing wet material such as low-grade coal to flow so as to dry the wet material; a crasher provided at an upstream side of the fluidized bed drying device, for crushing the wet material into fine particles and coarse particles; a classifying unit for classifying part of the coarse particles from the crushed material and providing mixed particles including the fine particles and unclassified coarse particles to the fluidized bed drying device; and a drainage treatment tank for receiving the coarse particles classified by the classifying unit and the coarse particles which are discharged from the fluidized bed drying device and which are included in the mixed particles, and provided with an absorption container having an activated carbon adsorption layer obtained by applying biological treatment, wherein condensed water from the fluidized bed drying device is introduced into the drainage treatment tank, and is passed through the activated carbon adsorption layer that has been subjected to the biological treatment to be purified.

2. A fluidized bed drying apparatus comprising: a fluidized bed drying device for receiving fluidized gas and causing wet material such as low-grade coal provided to a drying chamber to flow to dry the wet material to produce dried coal; a crasher provided at an upstream side of the fluidized bed drying device, for crushing the wet material into fine particles and coarse particles; 31 a classifying unit for classifying part of coarse particles from the crushed material and providing mixed particles including the fine particles and unclassified coarse particles to the fluidized bed drying device; a gasification furnace for processing the dried coal provided from the fluidized bed drying device so as to change the dried coal into gasification gas; and a drainage treatment tank for extracting part of char included together with the gasification gas, receiving the extracted char, and provided with an absorption container having an activated carbon adsorption layer obtained by applying biological treatment, wherein condensed water from the fluidized bed drying device is introduced into. the drainage treatment tank, and is passed through the activated carbon adsorption layer that has been subjected to the biological treatment to be purified.

3. The fluidized bed drying apparatus according to claim 1, further comprising: a first absorption container for receiving the coarse particles discharged from the fluidized bed drying device and having an activated carbon adsorption layer obtained by applying the biological treatment; and a second absorption container for receiving char and having an activated carbon adsorption layer obtained by applying the biological treatment Wherein the first and second absorption containers are provided continuously in the drainage treatment tank.

4. The fluidized bed drying apparatus according to any one of claims 1 to 3, wherein one of or both of an ozone treatment tank and 32 a filtration treatment tank is provided at an upstream side of the drainage treatment tank.

5. An integrated gasification combined cycle system comprising: the fluidized bed drying apparatus according to any one of claims 1 to 4; a gasification furnace for processing dried coal provided from the fluidized bed drying device so as to change the dried coal into gasification gas; a gas turbine for operating using the gasification gas as fuel; a steam turbine for operating with steam generated by a heat recovery steam generator receiving turbine flue gas from the gas turbine; and an electric power generator coupled with the gas turbine and/or the steam turbine.

6. The integrated gasification combined cycle system according to claim 5 further comprising: a char recovery device for recovering char included together with the gasification gas from the gasification furnace; and an extracting unit for extracting part of the char recovered by the char recovery device.

7. The integrated gasification combined cycle system according to claims 5 and 6, wherein the purified condensed water is used again as makeup water such as cooling water and industrial water.

8. A drainage treating method comprising: crushing wet material such as low-grade coal into 33 coarse particles and fine particles; classifying part of coarse particles from the wet material; providing mixed particles including the fine particle and the coarse particles which are not classified in the classifying to a fluidized bed drying device; receiving fluidized gas and causing the mixed particles to flow to dry the mixed particles; dropping the coarse particles included in the mixed particles into a drainage treatment tank provided with an absorption container having an activated carbon adsorption layer obtained by applying biological treatment; and introducing condensed water from the fluidized.bed drying device into the drainage treatment tank, and passing the condensed water through the activated carbon adsorption layer having been subjected to the biological treatment to purify the condensed water.

9. A drainage treating method comprising: crushing wet material such as low-grade coal into coarse particles and fine particles; classifying part of coarse particles from the wet material; providing mixed particles including the fine particle and the coarse particles which are not classified in the classifying to a fluidized bed drying device; receiving fluidized gas and causing the mixed particles to flow to dry the mixed particles, thus generating dried coal; processing the dried coal provided from the fluidized bed drying device to change the dried coal into gasification gas; extracting part of the char included together with the - 34 gasification gas and dropping the extracted char into a drainage treatment tank provided with an absorption container having an activated carbon adsorption layer obtained by applying biological treatment; and introducing the condensed water from the fluidized bed drying device into the drainage treatment tank, and passing the condensed water through the activated carbon adsorption layer having been subjected to the biological treatment to purify the condensed water.

10. A lifetime determining method of an activated carbon adsorption layer using the fluidized bed drying apparatus according to claim 1 or 2, wherein a differential pressure gauge is provided to measure differential pressures before and after the activated carbon adsorption layer, and change of the differential pressure is monitored after a predetermined period of time passes, and, when a predetermined pressure setting value is attained, it is determined that a lifetime of the activated carbon treatment layer is reached.

11. A fluidized bed drying apparatus substantially as herein described with reference to any one of the embodiments of the invention illustrated in the accompanying drawings and/or examples.

12. An integrated gasification combined cycle power generating facility substantially as herein described with reference to any one of the embodiments of the invention illustrated in the accompanying drawings and/or examples.

13. A drainage treatment method substantially as herein described with reference to any one of the embodiments of the invention illustrated in the accompanying drawings and/or examples. - 35

14. A lifetime determining method of an activated carbon adsorption layer substantially as herein described with reference to any one of the embodiments of the invention illustrated in the accompanying drawings and/or examples.