AU2012259944B2

AU2012259944B2 - Fluidized bed drying device

Info

Publication number: AU2012259944B2
Application number: AU2012259944A
Authority: AU
Inventors: Kenichi Arima; Ryuhei Takashima; Isao Torii
Original assignee: Mitsubishi Heavy Industries Ltd
Current assignee: Mitsubishi Heavy Industries Ltd
Priority date: 2011-05-20
Filing date: 2012-05-18
Publication date: 2015-06-11
Anticipated expiration: 2032-05-18
Also published as: WO2012161131A1; AU2012259944A1

Abstract

A drying furnace (5) that forms a fluidized bed (3) internally by using a fluidized gas to force lignite to flow is provided. The drying furnace (5) is divided into a first drying chamber (21) that carries out an initial drying of lignite, and a second drying chamber (22) that carries out a final drying of the lignite. In the first drying chamber (21), the lignite that is supplied is dried while undergoing completely mixed flow, and in the second drying chamber (22), the lignite that is supplied from the first drying chamber is dried while undergoing plug flow.

Description

DESCRIPTION FLUID-BED DRIER Field [0001] The present invention relates to a fluid-bed 5 drier that dries wetting fuel such as lignite with fluidizing the wetting fuel. Background [0002] A control device capable of controlling a coal dry and classification apparatus that dries the coal 10 supplied to a fluidizing and drying room with fluidizing the coal with hot air blowing from under the coal has been known in the past (For example, Patent Literature 1). The dry and classification apparatus controlled by the control device includes the fluidizing and drying room and a 15 classifying room such so as to dry the coal in the fluidizing and drying room and classify the coal into milled coal and coarse coal in the classifying room. Citation List Patent Literature 20 [0003] Patent Literature 1: Japanese Laid-open Patent Publication 7-11270 [0003a] Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part 25 of common general knowledge in the field. Summary Technical Problem [0004] However, such a dry and classification apparatus in the past dries coal in the fluidizing and drying room 30 with fluidizing the coal from the upper stream to the lower stream of the direction in which the coal is to fluidize. The coal supplied to the fluidizing and drying room tends to diffuse in the direction in which the coal is to 1 fluidize at that time. Thus, a part of the coal possibly flows into the classifying room at the lower stream of the direction in which the coal is to fluidize as the coal has not been dried. Thus, it is difficult to sufficiently dry 5 the coal in the dry and classification apparatus in the past because the coal that has not been dried is mixed with the dried coal in the classifying room. [0005] In light of the foregoing, an objective of the present invention is to provide a fluid-bed drier capable 10 of sufficiently drying wetting fuel. [0005a] It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative. [0005b] Unless the context clearly requires otherwise, 15 throughout the description and the claims, the words "comprise", "comprising", and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to". 20 Solution to Problem [0006] According to an aspect of the present invention, a fluid-bed drier includes: a drying furnace configured to form a fluid bed therein by fluidizing wetting fuel with fluidizing gas; 25 a recirculation line configured to cause the wetting fuel to flow out of the first drying room and to flow into the first drying room again; and a foreign matter removing unit provided on the recirculation line and configured to remove foreign matter 30 from the wetting fuel passing through the recirculation line. The drying furnace is divided into a first drying room in which the wetting fuel is dried by an initial dry and a second drying room in which the wetting fuel supplied 2 from the first drying room is dried by a late dry, the supplied wetting fuel is dried as being formed into a complete mixed flow in the first drying room, and the wetting fuel supplied from the first drying room is dried 5 as being formed into a flow along a direction in which the wetting fuel is to fluidize in the second drying room. [0007] According to the structure, the supplied wetting fuel can be dried because of the complete mixed flow in the first drying room such that the moisture content of the 10 wetting fuel is uniform. Thus, the homogenous wetting fuel can be supplied to the second drying room. The supplied wetting fuel can be dried along the direction in which the wetting fuel is to fluidize because of the flow along the direction in which the wetting fuel is to fluidize in the 15 second drying room. Thus, the wetting fuel can be dried in the first drying room and the second drying room. This can sufficiently dry the wetting fuel. [0008] Advantageously, in the fluid-bed drier, the flow along the direction in which the wetting fuel is to 20 2a Docket No. PMHA-13050-PCT fluidize is an extruded flow. [0009] According to the structure, the supplied wetting fuel can be dried without diffusing the wetting fuel in the direction in which the wetting fuel is to fluidize because 5 of the extruded flow in the second drying room. This makes it difficult for the wetting fuel that has not been dried to move across the dried wetting fuel and can prevent the discharge of the wetting fuel that has not been dried. Thus, the wetting fuel can sufficiently be dried. 10 [0010] Advantageously, in the fluid-bed drier, the second drying room includes a plurality of drying compartments that is divided in the direction in which the wetting fuel is to fluidize. [0011] According to the structure, the wetting fuel 15 supplied from the first drying room is dried as passing through all of the drying compartments in the second drying room. Thus, the wetting fuel can be dried in a plurality of drying compartments. This can sufficiently dry the wetting fuel over time. 20 [0012] Advantageously, the fluid-bed drier further includes: a recirculation line configured to cause the wetting fuel to flow out of the first drying room and to flow into the first drying room again; and a foreign matter removing unit provided on the recirculation line and 25 configured to remove foreign matter from the wetting fuel passing through the recirculation line. [0013] According to the structure, providing the recirculation line can discharge the wetting fuel that is currently dried from the first drying room and can supply 30 the discharged wetting fuel to the first drying room again. Thus, both of the wetting fuel that is currently dried and the wetting fuel that has not been dried are supplied to the first drying room. Supplying the wetting fuel that is 3 Docket No. PMHA-13050-PCT currently dried can facilitate the dry of the wetting fuel. At that time, providing a foreign matter removing unit on the recirculation line can remove foreign matter from the wetting fuel flowing in the recirculation line. This can 5 prevent the foreign matter from blocking the recirculation line. Note that the foreign matter includes, for example, the metal or wood mixed with the wetting fuel, or the solid of condensed wetting fuel. [0014] Advantageously, in the fluid-bed drier, the 10 recirculation line includes a fuel discharge port configured to cause the wetting fuel to flow out of the first drying room, and the fuel discharge port is connected to a bottom surface on the first drying room side of a boundary between the first drying room and the second 15 drying room. [0015] According to the structure, the wetting fuel before flowing into the second drying room or, namely, the wetting fuel dried by the initial dry can be circulated again. This can further facilitate the dry of the wetting 20 fuel in the first drying room. [0016] Advantageously, in the fluid-bed drier, the second drying room is provided with a holding back unit on a bottom surface on the second drying room side of the boundary between the first drying room and the second 25 drying room. [0017] According to the structure, a part of the wetting fuel supplied from the first drying room to the second drying room can be held back with a holding back unit. Thus, the held back wetting fuel can flow into the fuel 30 discharge port on the recirculation line. This can increase the amount of the wetting fuel that flows into the recirculation line. This can further facilitate the dry of the wetting fuel in the first drying room. 4 Docket No. PMHA-13050-PCT [0018] It is preferable in that case that the recirculation line includes a re-feed port configured to cause the wetting fuel that has flowed out of the first drying room to flow into the first drying room and the re 5 feed port is connected to the first drying room. [0019] According to the structure, the wetting fuel flowing in the recirculation line can directly be supplied to the first drying room. [0020] It is preferable in that case that the 10 recirculation line includes a re-feed port configured to cause the wetting fuel that has flowed out of the first drying room to flow into the first drying room and the re feed port is connected to a fuel banker configured to store the wetting fuel that is to be supplied to the first drying 15 room. [0021] According to the structure, the wetting fuel flowing in the recirculation line can indirectly be supplied to the first drying room through the fuel banker. [0022] Advantageously, in the fluid-bed drier, a floor 20 area ratio of the first drying room and the second drying room is "the first drying room : the second drying room = 30 to 50% : 70 to 50%". [0023] According to the structure, the wetting fuel fluidizing in the first drying room and in the second 25 drying room can be dried depending on the floor area ratio. This can preferably dry the wetting fuel in the first drying room and in the second drying room. [0024] Advantageously, the fluid-bed drier, further includes a plurality of dividing members that is provided 30 in the second drying room and is positioned at predetermined intervals in the direction in which the wetting fuel is to fluidize. The dividing members form spaces with a bottom of the second drying room, and each of 5 Docket No. PMHA-13050-PCT the dividing members includes a panel tube that is heat exchanger tubes formed into a panel shape. [0025] According to the structure, the wetting fuel in the second drying room can be heated with the panel tube. 5 This can sufficiently dry the wetting fuel. [0026] Advantageously, the fluid-bed drier further includes a plurality of heat exchanger tubes positioned at an inside of the fluid bed between the dividing members. [0027] According to the structure, the wetting fuel can 10 further be heated with the heat exchanger tubes. This can further facilitate the dry of the wetting fuel. Note that the heat exchanger tubes can also be formed into a grid pattern or a staggered pattern. [0028] Advantageously, in the fluid-bed drier, the 15 spaces are provided such that the spaces become narrower as being located at lower stream. [0029] According to the structure, the wetting fuel located between the dividing members becomes less able to fluidize as moving to the lower stream of the direction in 20 which the wetting fuel is to fluidize. This can increase the retention time in which the wetting fuel remains. This can increase the heating time of the wetting fuel. Thus, the dry of the wetting fuel can further be facilitated. [0030] It is preferable in that case that the dividing 25 members further include a dividing panel connected to the panel tube. The panel tube is positioned at the inside of the fluid bed. The dividing plate is positioned at the outside of the fluid bed. [0031] According to the structure, providing the 30 dividing plate can prevent the wetting fuel that has not been dried from moving across the panel tube. Thus, the wetting fuel can fluidize as passing through the spaces between the dividing members and the bottom of the drying 6 Docket No. PMHA-13050-PCT room. This can sufficiently dry the wetting fuel. [0032] Advantageously, in the fluid-bed drier further includes a flow adjusting unit that is provided at a space between the dividing member positioned at an end of the 5 lower stream of the direction in which the wetting fuel is to fluidize and the bottom of the second drying room and that is capable of adjusting the flow of the wetting fuel flowing out of the space. [0033] According to the structure, the flow of the 10 wetting fuel flowing out of the space at the end of the lower stream in the direction in which the wetting fuel is to fluidize can be adjusted. Thus, adjusting the flow of the wetting fuel can adjust the retention time of the wetting fuel. This can appropriately adjust the flow 15 according to the degree of dry of the wetting fuel in the drying room. Advantageous Effects of Invention [0034] The fluid-bed drier of the present invention can dry the wetting fuel supplied in the second drying room 20 without diffusing the wetting fuel along the direction in which the wetting fuel is to fluidize. This makes it difficult for the wetting fuel that has not been dried to move across the dried wetting fuel. Thus, the wetting fuel can preferably be dried while the discharge of the wetting 25 fuel that has not been dried is prevented. Brief Description of Drawings [0035] FIG. 1 is a schematic structure diagram of an integrated coal gasification combined cycle applying a fluid-bed drier according to a first embodiment. 30 FIG. 2 is a schematic structure diagram schematically illustrating the fluid-bed drier according to the first embodiment. FIG. 3 is a schematic structure diagram schematically 7 Docket No. PMHA-13050-PCT illustrating a fluid-bed drier according to a second embodiment. FIG. 4 is a schematic structure diagram schematically illustrating a fluid-bed drier according to an exemplary 5 variation. FIG. 5 is a schematic structure diagram schematically illustrating a fluid-bed drier according to a third embodiment. Description of Embodiments 10 [0036] Hereinafter, a fluid-bed drier according to the present invention will be described with reference to the accompanying drawings. Note that the present invention is not limited to the embodiments to be described below. Further, the components in the embodiments include 15 components that are exchangeable and simply for persons skilled in the art, or materials substantially equivalent to the components. [First Embodiment] [0037] FIG. 1 is a schematic structure diagram of an 20 integrated coal gasification combined cycle applying a fluid-bed drier according to a first embodiment. An Integrated Coal Gasification Combined Cycle (IGCC) 100 applying a fluid-bed drier 1A according to the first embodiment employs an air combustion system that generates 25 gasified coal in a gasification furnace with the air as oxidant so as to generate electric power with supplying the gasified coal purified in a gas refinery as combustion gas to a gas turbine facility. In other words, the integrated coal gasification combined cycle 100 according to the first 30 embodiment is an air combustion (air blown) power plant. Lignite is used as wetting material to be supplied to the gasification furnace in that case. [0038] Note that any fuel that has high moisture content, 8 Docket No. PMHA-13050-PCT for example, low rank coal including subbituminous coal, peat including sludge, or high rank coal can also be used as the wetting material although lignite is used in the first embodiment. Further, not only coal including lignite 5 but also biomass used as reusable biological organic resource can be used as the wetting material. For example, forest thinning wood, scrap wood, driftwood, grasses, waste materials, sludge, or tires, or recycle fuel (pellets or chips) made of the above-mentioned materials can also be 10 used. [0039] As illustrated in FIG. 1, the integrated coal gasification combined cycle 100 includes a stoker 111, the fluid-bed drier 1A, a coal mill 113, a coal gasification furnace 114, a char recovery unit 115, a gas refinery 116, 15 a gas turbine unit 117, a steam turbine unit 118, a generator 119, and an Heat Recovery Steam Generator (HRSG) 120 in the first embodiment. [0040] The stoker 111 includes a raw coal banker 121, a coal supplier 122, and a crasher 123. The raw coal banker 20 121 is capable of storing lignite so as to drop a predetermined amount of lignite to the coal supplier 122. The coal supplier 122 conveys the lignite dropped from the raw coal banker 121 with a conveyer or the like and drops the dropped lignite to the crasher 123. The crasher 123 25 finely crashes the dropped lignite so as to grind the lignite to fine particles. [0041] The fluid-bed drier 1A supplies drying steam such as superheated steam to the lignite input from the stoker 111 so as to heat and dry the lignite with fluidizing the 30 lignite so as to remove the moisture content from the lignite. The fluid-bed drier 1A is provided with a cooler 131 that cools the dried lignite (dry coal) extracted from the lower part such that the dried and cooled dry coal is 9 Docket No. PMHA-13050-PCT stored in a dry coal banker 132. The fluid-bed drier 1A is further provided with a dry coal cyclone 133 and an electronic dry coal precipitator 134 that separate particles of the dry coal from the steam extracted from the 5 upper part of the fluid-bed drier 1A such that the particles of the dry coal separated from the steam are stored in the dry coal banker 132. Note that the steam from which the dry coal has been separated in the electronic dry coal precipitator 134 is supplied to the 10 fluid-bed drier 1A as drying steam after being compressed in a steam compressor 135. [0042] The coal mill 113 is a coal grinder that crashes the lignite dried in the fluid-bed drier 1A (dry coal) to fine particles so as to produce milled coal. In other 15 words, when the dry coal stored in the dry coal banker 132 is dropped with a coal feeder 136, the coal mill 113 mills the dry coal to milled coal having a predetermined particle diameter. Then, the coal milled in the coal mill 113 is separated from conveying gas in milled coal bag filters 20 137a and 137b and is stored in milled coal feed hoppers 138a and 138b. [0043] The coal gasification furnace 114 is supplied with the milled coal processed in the coal mill 113 and the char (unburned combustible components of the coal) 25 recovered in the char recovery unit 115. [0044] The coal gasification furnace 114 is connected to a compressed air feed line 141 from the gas turbine unit 117 (a compressor 161) such that the air compressed in the gas turbine unit 117 can be supplied. An air separator 142 30 is configured to separate and produce nitrogen and oxygen from the atmosphere. A first nitrogen feed line 143 is connected to the coal gasification furnace 114. Coal feed lines 144a and 144b from the milled coal feed hoppers 138a 10 Docket No. PMHA-13050-PCT and 138b are connected to the first nitrogen feed line 143. A second nitrogen feed line 145 is also connected to the coal gasification furnace 114. A char return line 146 from the char recovery unit 115 is connected to the second 5 nitrogen feed line 145. An oxygen feed line 147 is connected to the compressed air feed line 141. In that case, the nitrogen is used as the gas for conveying the coal and the char. The oxygen is used as oxidant. [0045] The coal gasification furnace 114 is, for example, 10 an entrained-bed gasification furnace that burns and gasifies the coal, char, and air (oxygen) or steam used as gasifying agent that have been supplied therein, and generates carbon dioxide-based combustible gas (produced gas, or gasified coal) so as to cause gasification reaction 15 using the combustible gas as gasifying agent. Note that the coal gasification furnace 114 is provided with a foreign matter removal device 148 that removes a foreign matter mixed with the milled coal. In that case, the coal gasification furnace 114 is not limited to an entrained-bed 20 gasification furnace and can also be a fluid-bed gasification furnace or a fixed-bed gasification furnace. The coal gasification furnace 114 is provided with a gas production line 149 of the combustible gas directed to the char recovery unit 115 such that the combustible gas 25 including the char can be exhausted. In that case, providing a gas cooler on the gas production line 149 can supply the combustible gas to the char recovery unit 115 after cooling the combustible gas to a predetermined temperature. 30 [0046] The char recovery unit 115 includes a precipitator 151 and a feed hopper 152. In that case, the precipitator 151 includes one or a plurality of bag filters or cyclones so as to separate the char from the combustible 11 Docket No. PMHA-13050-PCT gas produced in the coal gasification furnace 114. Then, the combustible gas from which the char has been separated is sent to the gas refinery 116 through a gas emission line 153. The feed hopper 152 is configured to store the char 5 separated from the combustible gas in the precipitator 151. Note that a bin can be provided between the precipitator 151 and the feed hopper 152 such that a plurality of feed hoppers 152 can be connected to the bin. The char return line 146 from the feed hopper 152 is connected to the 10 second nitrogen feed line 145. [0047] The gas refinery 116 is configured to purify the combustible gas from which the char has been separated in the char recovery unit 115 by removing impurities such as sulfur compound or nitrogen compound from the combustible 15 gas. The gas refinery 116 produces fuel gas by purifying the combustible gas so as to supply the gas to the gas turbine unit 117. Note that sulfur content (H 2 S) is still included in the combustible gas from which the char has been separated in the gas refinery 116. The sulfur content 20 is removed by amine absorbent and is finally recovered as gypsum for efficient use. [0048] The gas turbine unit 117 includes the compressor 161, a combustor 162, and a turbine 163. The compressor 161 is communicated with the turbine 163 through a rotary 25 shaft 164. The combustor 162 is connected to a compressed air feed line 165 from the compressor 161 and is connected to a fuel gas feed line 166 from the gas refinery 116. A combustion gas feed line 167 is connected to the turbine 163. The gas turbine unit 117 is provided with the 30 compressed air feed line 141 extending from the compressor 161 to the coal gasification furnace 114. A booster 168 is provided on the compressed air feed line 141. Thus, the compressed air supplied from the compressor 161 and the 12 Docket No. PMHA-13050-PCT fuel gas supplied from the gas refinery 116 are mixed with each other and burnt in the combustor 162. Rotating the rotary shaft 164 with the generated combustion gas in the turbine 163 can drive the generator 119. 5 [0049] The steam turbine unit 118 includes a turbine 169 communicated with the rotary shaft 164 in the gas turbine unit 117. The generator 119 is communicated with the base end of the rotary shaft 164. The heat recovery steam generator 120 is provided on a flue gas line 170 from the 10 gas turbine unit 117 (the turbine 163) so as to produce steam by exchanging the heat between the air and the hot flue gas. Thus, a steam feed line 171 and a steam recovery line 172 including a steam condenser 173 are provided between the heat recovery steam generator 120 and the 15 turbine 169 of the steam turbine unit 118. Thus, the turbine 169 driven by the steam supplied from the heat recovery steam generator 120 rotates the rotary shaft 164 in the steam turbine unit 118 so that the rotary shaft 164 can drive the generator 119. 20 [0050] A gas purification device 174 removes toxic substance from the flue gas of which heat has been recovered in the heat recovery steam generator 120. The purified flue gas is emitted from a stack 175 into the air. [0051] Hereinafter, the operation of the integrated coal 25 gasification combined cycle 100 in the present embodiment will be described. [0052] The integrated coal gasification combined cycle 100 in the present embodiment stores raw coal (lignite) in the raw coal banker 121 of the stoker 111. The coal 30 supplier 122 drops the lignite in the raw coal banker 121 to the crasher 123 such that the lignite is crushed into a predetermined size. The crushed lignite is heated and dried in the fluid-bed drier 1A and is cooled with a cooler 13 Docket No. PMHA-13050-PCT 131. Then, the lignite is stored in the dry coal banker 132. The steam extracted from the upper part of the fluid bed drier 1A is compressed in the steam compressor 135 after the particles of dry coal are removed from the steam 5 in the dry coal cyclone 133 and the electronic dry coal precipitator 134. After that, the steam returns to the fluid-bed drier 1 as drying steam. On the other hand, the particles of dry coal separated from the steam are stored in the dry coal banker 132. 10 [0053] The dry coal stored in the dry coal banker 132 is input to the coal mill 113 from the coal feeder 136 such that the dry coal is milled into fine particles and milled coal is produced therein. The milled coal is stored in the milled coal feed hoppers 138a and 138b through the milled 15 coal bag filters 137a and 137b. The milled coal stored in the milled coal feed hoppers 138a and 138b is supplied to the coal gasification furnace 114 through the first nitrogen feed line 143 with the nitrogen supplied from the air separator 142. The char recovered with the char 20 recovery unit 115 to be described below is supplied to the coal gasification furnace 114 through the second nitrogen feed line 145 with the nitrogen supplied from the air separator 142. Further, after being boosted in the booster 168, the compressed air extracted from the gas turbine unit 25 117 to be described below is supplied to the coal gasification furnace 114 through the compressed air feed line 141 with the oxygen supplied from the air separator 142. [0054] The coal gasification furnace 114 can generate 30 carbon dioxide-based combustible gas (gasified coal) by burning the milled coal and char supplied thereto with the compressed air (oxygen) and gasifying the milled coal and the char. Then, the combustible gas is emitted from the 14 Docket No. PMHA-13050-PCT coal gasification furnace 114 through the gas production line 149 and is sent to the char recovery unit 115. [0055] The combustible gas is first supplied to the precipitator 151 such that the precipitator 151 separates 5 the char from the combustible gas in the char recovery unit 115. Then, the combustible gas from which the char has been separated is sent to the gas refinery 116 through the gas emission line 153. On the other hand, the fine char separated from the combustible gas accumulates in the feed 10 hopper 152 and returns to the coal gasification furnace 114 through the char return line 146 for recycling. [0056] The combustible gas from which the char has been separated in the char recovery unit 115 is purified by a removal of impurities such as sulfur compound or nitrogen 15 compound from the combustion gas in the gas refinery 116 so as to produce fuel gas. The compressor 161 generates the compressed air and supplies the compressed air to the combustor 162 in the gas turbine unit 117. The combustor 162 mixes the compressed air supplied from the compressor 20 161 with the fuel gas supplied from the gas refinery 116 and burns the mixed gas so as to generate combustion gas. The combustion gas drives the turbine 163 so as to drive the generator 119 through the rotary shaft 164. This can generate electric power. 25 [0057] The flue gas emitted from the turbine 163 in the gas turbine unit 117 generates steam by exchanging the heat with the air in the heat recovery steam generator 120. The generated steam is supplied to the steam turbine unit 118. The steam supplied from the heat recovery steam generator 30 120 drives the turbine 169 so as to drive the generator 119 through the rotary shaft 164 in the steam turbine unit 118. This can generate electric power. [0058] After that, the toxic substance is removed from 15 Docket No. PMHA-13050-PCT the flue gas emitted from the heat recovery steam generator 120 in the gas purification device 174 and the purified flue gas is emitted from the stack 175 into the air. [0059] Hereinafter, the fluid-bed drier 1A in the above 5 mentioned integrated coal gasification combined cycle 100 will be described in detail. FIG. 2 is a schematic structure diagram schematically illustrating the fluid-bed drier according to the first embodiment. The fluid-bed drier 1A in the first embodiment heats and dries lignite 10 that is coal having a high moisture content with fluidizing the lignite with fluidizing gas. [0060] The fluid-bed drier 1A includes a drying furnace 5 to which lignite is supplied and a gas diffusing plate 6 provided in the drying furnace 5. The drying furnace 5 is 15 formed into a rectangular box shape. The lignite supplied to the drying furnace 5 forms a fluid bed 3 in the drying furnace 5 by fluidizing with the fluidizing gas. The fluid bed 3 formed in the drying furnace 5 fluidizes in the longitudinal direction of the drying furnace 5 (horizontal 20 direction in FIG. 2). The gas diffusing plate 6 separates the internal space of the drying furnace 5 into a chamber room 11 located on the vertically lower side (the lower side in the drawing) and a drying room 12 located on the vertically upper side (the upper side in the drawing). A 25 number of through holes are formed on the gas diffusing plate 6 so as to introduce the fluidizing gas such as steam into the chamber room 11. [0061] The drying room 12 formed in the drying furnace 5 includes a first drying room 21 provided on the upper 30 stream of the direction in which the lignite is to fluidize and a second drying room 22 provided on the lower stream of the direction in which the lignite is to fluidize. The first drying room 21 and the second drying room 22 are 16 Docket No. PMHA-13050-PCT communicated with each other. The first drying room 21 is a complete mixing area in which the initial dry is performed. The second drying room 22 is an extrusion area (plug flow area) in which the late dry is performed. 5 [0062] The first drying room 21 is configured to cause the supplied lignite to be a complete mixed flow therein. The complete mixed flow means a flow in which the lignite is mixed such that the moisture content of the lignite is uniform in the fluid bed 3 formed in the first drying room 10 21. Thus, back mixing in which the lignite is mixed with a back flow in the direction in which the lignite is to fluidize is allowed in the first drying room 21. The first drying room 21 is provided with a feed port 31 that supplies the lignite and a heat exchanger tube 33 that 15 heats the lignite. [0063] The feed port 31 is connected to the sidewall of the first drying room 21 at the upper stream of the direction in which the lignite is to fluidize so as to work as a feed opening for supplying the lignite to the first 20 drying room 21. The crasher 123 is connected to the feed port 31 such that the finely grinded lignite is supplied to the first drying room 21. [0064] The heat exchanger tube 33 is provided in the fluid bed 3. The drying steam is supplied to the inside of 25 the heat exchanger tube 33 so as to remove the moisture content from the lignite in the fluid bed 3. Thus, when the drying steam is supplied to the heat exchanger tube 33, the heat exchanger tube 33 dries the lignite in the first drying room 21 using the latent heat of the drying steam. 30 After that, the drying steam used for drying the lignite is emitted to the outside of the first drying room 21. [0065] Thus, when the lignite is supplied from the feed port 31, the supplied lignite forms the fluid bed 3 by 17 Docket No. PMHA-13050-PCT fluidizing with the fluidizing gas supplied through the gas diffusing plate 6. The lignite formed into the fluid bed 3 is dried when being heated with the fluidizing gas and the heat exchanger tube 33. 5 [0066] This can cause the lignite formed into the fluid bed 3 in the first drying room 21 to be a complete mixed flow. Thus, the lignite that is the complete mixed flow can be dried as being homogenized in the fluid bed 3 in the first drying room 21. At that time, the steam generated by 10 drying the lignite is emitted to the dry coal cyclone 133 from the steam emission port 42 provided in the second drying room 22 to be described below. Then, the lignite dried by the initial dry in the first drying room 21 is supplied to the second drying room 22. Note that the 15 lignite, for example, having the moisture content of around 60% is dried to around 40% by the initial dry in the first drying room 21. [0067] The second drying room 22 is configured such that the supplied lignite flows along the direction in which the 20 lignite is to fluidize therein. Especially, the second drying room 22 is configured such that the lignite is formed into an extruded flow. The extruded flow means a flow in which the lignite is extruded in the direction in which the lignite is to fluidize to prevent the lignite 25 from diffusing in the direction in which the lignite is to fluidize in the fluid bed 3 formed in the second drying room 22. The second drying room 22 is provided with an discharge port 41 from which the lignite is discharged, the steam emission port 42 from which the generated steam is 30 emitted, a plurality of dividing members 43, a plurality of heat exchanger tubes 44, and a flow adjusting unit 47. [0068] The discharge port 41 is connected to the bottom of the second drying room 22 at the lower stream of the 18 Docket No. PMHA-13050-PCT direction in which the lignite is to fluidize so as to work as a discharge opening for discharging the lignite from the second drying room 22. The lignite dried by the late dry in the second drying room 22 is discharged as dry coal from 5 the discharge port 41. The discharged dry coal is supplied toward the cooler 131. [0069] The steam emission port 42 is connected to the upper surface of the second drying room 22 at the lower stream of the direction in which the lignite is to fluidize 10 so as to work as an emission opening for emitting the steam generated from the first drying room 21 and from the second drying room 22 when the lignite is dried. Note that the generated steam emitted from the steam emission port 42 is supplied toward the dry coal cyclone 133. 15 [0070] The dividing members 43 are positioned at predetermined intervals in the direction in which the lignite is to fluidize. Thus, the dividing members 43 divide the second drying room 22 into a plurality of drying compartments 45. The drying compartments 45 are formed 20 side by side in the direction in which the lignite is to fluidize. Each of the dividing members 43 includes a panel tube 51 provided in the fluid bed 3, and a dividing plate 52 provided at the outside of the fluid bed 3. The dividing plate 52 is connected on the upper side of the 25 panel tube 51. [0071] The panel tube 51 is formed with heat exchanger tubes vertically arranged side by side such that the heat exchanger tubes are formed into a panel shape. The panel tube 51 circulates superheated steam therein so as to heat 30 the lignite forming the fluid bed 3. The dividing plate 52 prevents the lignite from moving into the drying compartment 45 at the lower stream over the panel tube 51. The dividing plate 52 is provided such that the plate 19 Docket No. PMHA-13050-PCT surface is perpendicular to the direction in which the lignite is to fluidize. [0072] Each of the dividing members 43 having the above mentioned structure is provided so as to have a space with 5 the gas diffusing plate 6 of the second drying room 22. The spaces work as a plurality of circulation openings 46. At that case, the dividing members 43 are provided such that the circulation openings 46 (spaces) become narrower as being located at the lower stream of the direction in 10 which the lignite is to fluidize. Specifically, the dividing members 43 are formed such that a dividing member 43 that is located at the lower stream has a shorter length in the vertical direction of the panel tube 51. [0073] The heat exchanger tubes 44 are provided at the 15 drying compartments 45, respectively such that the axial directions are the same as the width direction of the drying furnace 5. Some heat exchanger tubes 44 are vertically arranged and the other heat exchanger tubes 44 are arranged in the direction in which the lignite is to 20 fluidize such that the heat exchanger tubes 44 are formed into a grid pattern. Note that the heat exchanger tubes 44 are formed into a grid pattern in the present embodiment. However, the formation is not limited to the present embodiment. The heat exchanger tubes 44 can also be formed 25 into a staggered pattern. [0074] The flow adjusting unit 47 includes a flow dividing plate 55 provided at the further lower stream than the circulation opening 46 at the end of the lower stream of the direction in which the lignite is to fluidize. A 30 driving mechanism (not illustrated in the drawings) vertically moves the flow dividing plate 55. Thus, the flow adjusting unit 47 can adjust the flow of the lignite discharged from the circulation opening 46 by adjusting the 20 Docket No. PMHA-13050-PCT vertical length of the circulation opening 46 at the end of the lower stream. Specifically, the flow adjusting unit 47 reduces the discharge of the lignite by narrowing the circulation opening 46 when the lignite is insufficiently 5 dried. This increases the retention time of the lignite in the drying compartments 45, so that the heating time of the lignite can be increased. On the other hand, the flow adjusting unit 47 increases the discharge of the lignite by expanding the circulation opening 46 when the lignite is 10 excessively dried. This shortens the retention time of the lignite in the drying compartments 45, so that the heating time of the lignite can be reduced. [0075] Thus, after the lignite dried by the initial dry is supplied from the first drying room 21, the supplied 15 lignite is supplied to the drying compartment 45 at the start of the upper stream of the second drying room 22 through the circulation opening 46 between the dividing member 43 at the start of the upper stream of the direction in which the lignite is to fluidize and the gas diffusing 20 plate 6. The lignite supplied to the drying compartment 45 is formed into the fluid bed 3 by fluidizing with the fluidizing gas supplied through the gas diffusing plate 6. The lignite formed into the fluid bed 3 is heated and dried with the fluidizing gas, the panel tube 51, and the heat 25 exchanger tubes 44. The lignite dried in the drying compartment 45 is extruded to the drying compartment 45 at the lower stream through the circulation opening 46 between the dividing member 43 at the lower stream in the direction in which the lignite is to fluidize and the gas diffusing 30 plate 6. [0076] At that time, the circulation openings 46 become narrower as being located at the lower stream of the direction in which the lignite is to fluidize. Thus, the 21 Docket No. PMHA-13050-PCT flow of the lignite from a circulation opening 46 decreases every time when the lignite moves to a drying compartment 45 at the lower stream. This facilitates the retention of the lignite in each of the drying compartments 45. Thus, 5 the heating time can be increased. [0077] Then, the lignite flows out of the circulation opening 46 at the end of the lower stream of which flow has been adjusted with the flow adjusting unit 47. Note that the flow adjusting unit 47 adjusts the opening area of the 10 circulation opening 46 depending on the degree of dry of the lignite. The flow adjusting unit 47 adjusts the amount of the remaining lignite in the drying compartments 45 by adjusting the flow of the lignite discharged from the circulation opening 46. As described above, the lignite 15 moves as being extruded from a drying compartment 45 at the upper stream to a drying compartment 45 at the lower stream. While passing through all of the drying compartments 45, the lignite is dry by the late dry. [0078] Thus, the lignite formed into the fluid bed 3 in 20 the second drying room 22 can be an extruded flow by sequentially moving through the drying compartments 45 from the upper stream. This can dry the lignite that is an extruded flow in the fluid bed 3 in the second drying room 22 without diffusing the lignite in the direction in which 25 the lignite is to fluidize. At that time, the steam generated when the lignite is dried is emitted from the steam emission port 42 provided at the second drying room 22. Then, the lignite dried by the late dry in the second drying room 22 is discharged as dry coal from the discharge 30 port 41. Note that the lignite, for example, having the moisture content of around 40% is dried to around 10% by the late dry in the second drying room 22. [0079] At that case, the floor area ratio between the 22 Docket No. PMHA-13050-PCT first drying room 21 and the second drying room 22 or, namely, the area ratio of the gas diffusing plate 6 in the room 21 and the gas diffusing plate 6 in the room 22 is "the first drying room : the second drying room = 30 to 5 50% : 70 to 50%". [0080] According to the structure in the first embodiment as described above, the supplied lignite can be heated and dried with the complete mixed flow in the first drying room 21 such that the moisture content of the 10 lignite is uniform. This can supply the homogenized lignite to the second drying room 22. The extruded flow can cause the supplied lignite to be heated and dried in the second drying room 22 without diffusing the lignite in the direction in which the lignite is to fluidize. This 15 makes it difficult for the lignite that has not been dried to move across the dried lignite and can prevent the discharge of the lignite that has not been dried. Thus, the lignite can sufficiently be dried. [0081] Further, the structure in the first embodiment 20 can dry the lignite supplied from the first drying room 21 toward the second drying room 22 while passing the lignite through all of the drying compartments 45. This can dry the lignite along the direction in which the lignite is to fluidize using the drying compartments 45. Thus, the 25 lignite can sufficiently be dried over time. [0082] Further, according to the structure in the first embodiment, providing the panel tube 51 in the second drying room 22 can cause the panel tube 51 to heat and dry the lignite. This can facilitate the dry of the lignite in 30 the second drying room 22. Thus, the lignite can sufficiently be dried. [0083] Further, according to the structure in the first embodiment, providing the heat exchanger tubes 44 in the 23 Docket No. PMHA-13050-PCT second drying room 22 can cause the heat exchanger tubes 44 to heat and dry the lignite. This can further facilitate the dry of the lignite in the second drying room 22. Thus, the lignite can sufficiently be dried. 5 [0084] Further, according to the structure in the first embodiment, the circulation openings 46 become narrower as being located at the lower stream of the direction in which the lignite is to fluidize. This can increase the detention time of the lignite in the drying compartments 45. 10 This can increase the heating time of the lignite. Thus, the dry of the lignite is further facilitated. [0085] Further, according to the structure in the first embodiment, providing the dividing plate 52 on the upper side of the panel tube 51 can prevent the lignite from 15 moving over the panel tube 51. This can move the lignite from a drying compartment 45 at the upper stream to a drying compartment 45 at the lower stream through the circulation opening 46. Thus, the lignite as an extruded flow can be dried. 20 [0086] Further, according to the structure in the first embodiment, the flow adjusting unit 47 adjusts the flow of the lignite from the circulation opening 46 at the end of the lower stream. This can adjust the degree of dry of the lignite. 25 [Second Embodiment] [0087] Next, a fluid-bed drier 1B according to the second embodiment will be described with reference to FIG. 3 and FIG. 4. FIG. 3 is a schematic structure diagram schematically illustrating the fluid-bed drier according to 30 the second embodiment. FIG. 4 is a schematic structure diagram schematically illustrating a fluid-bed drier according to an exemplary variation. To avoid the overlapping descriptions, the components different from the 24 Docket No. PMHA-13050-PCT first embodiment will be described in the second embodiment. The panel tubes 51 are provided in the second drying room 22 of the drying furnace 5 in the fluid-bed drier 1A according to the first embodiment. However, the fluid-bed 5 drier 1B according to the second embodiment has a structure in which panel tubes 51 are omitted. Hereinafter, the fluid-bed drier 1B according to the second embodiment will be described with reference to FIG. 3 and FIG. 4. [0088] Similarly to the fluid-bed drier 1A in the first 10 embodiment, the fluid-bed drier 1B includes a drying furnace 5 to which lignite is supplied and a gas diffusing plate 6 provided in the drying furnace 5. A drying room 12 formed in the drying furnace 5 includes a first drying room 21 and a second drying room 22. The first drying room 21 15 and the second drying room 22 are communicated with each other. The first drying room 21 is a complete mixing area in which the initial dry is performed. The second drying room 22 is an extrusion area (plug flow area) in which the late dry is performed. 20 [0089] The second drying room 22 is provided with a discharge port 41 from which the lignite is discharged, a steam emission port 42 from which the generated steam is emitted, and a plurality of dividing plates 43. The descriptions of the discharge port 41 and the steam 25 emission port 42 will be omitted because they are the same as in the first embodiment. [0090] The dividing plates 43 are positioned at predetermined intervals in the direction in which the lignite is to fluidize. Each of the dividing plates 43 is 30 provided such that the plate surface is perpendicular to the direction in which the lignite is to fluidize. Thus, the dividing plates 43 divide the second drying room 22 into a plurality of drying compartments 45. The drying 25 Docket No. PMHA-13050-PCT compartments 45 are formed side by side in the direction in which the lignite is to fluidize. Each of the dividing members 43 is provided so as to have a space with a gas diffusing plate 6 of the second drying room 22. The space 5 works as a circulation opening 46 for the lignite. [0091] Thus, when the lignite dried by the initial dry is supplied from the first drying room 21, the supplied lignite is supplied to the drying compartment 45 at the start of the upper stream in the second drying room 22 10 through the circulation opening 46 between the dividing plate 43 and a gas diffusing plate 6 at the start of the upper stream of the direction in which the lignite is to fluidize. The lignite supplied to the drying compartments 45 is formed into a fluid bed 3 by fluidizing with the 15 fluidizing gas supplied through the gas diffusing plate 6. The lignite that is the fluid bed 3 is dried with the fluidizing gas. The lignite dried in the drying compartment 45 is extruded to the drying compartment 45 at the lower stream through the circulation opening 46 between 20 the dividing plate 43 at the lower stream of the direction in which the lignite is to fluidize and the gas diffusing plate 6. As described above, the lignite moves as being extruded from a drying compartment 45 at the upper stream to a drying compartment 45 at the lower stream. While 25 passing through all of the drying compartments 45, the lignite is dry by the late dry. [0092] Thus, the lignite formed into the fluid bed 3 in the second drying room 22 can be an extruded flow by sequentially moving through the drying compartments 45 from 30 the upper stream. This can dry the lignite that is an extruded flow in the fluid bed 3 in the second drying room 22 without diffusing the lignite in the direction in which the lignite is to fluidize. At that time, the steam 26 Docket No. PMHA-13050-PCT generated when the lignite is dried is emitted from the steam emission port 42 provided at the second drying room 22. Then, the lignite dried by the late dry in the second drying room 22 is discharged as dry coal from the discharge 5 port 41. Note that the lignite, for example, having the moisture content of around 40% is dried to around 10% by the late dry in the second drying room 22. [0093] Note that the floor area ratio between the first drying room 21 and the second drying room 22 or, namely, 10 the area ratio of the gas diffusing plate 6 in the room 21 and the gas diffusing plate 6 in the room 22 is "the first drying room : the second drying room = 30 to 50% : 70 to 50%" in the second embodiment. [0094] Further, the fluid-bed drier 1 further includes a 15 recirculation line L that causes the lignite flowed out of the first drying room 21 to flow into the first drying room 21 again, a foreign matter removing device (foreign matter removing unit) 57 provided on the recirculation line L, and a holding back unit 58 that holds back a part of the 20 lignite to be supplied to the second drying room 22. [0095] The recirculation line L includes a lignite discharge port (fuel discharge port) 61 that causes the lignite to flow out of the first drying room 21, and a re feed port 62 that supplies the lignite to the first drying 25 room 21 again. The lignite discharge port 61 is provided on the first drying room 21 side of the boundary between the first drying room 21 and the second drying room 22 and is connected to the gas diffusing plate 6 that is the bottom surface of the first drying room 21. In other words, 30 the lignite discharge port 61 is connected to the gas diffusing plate 6 that is the bottom surface of the first drying room 21 at the lower stream of the direction in which the lignite is to fluidize. The re-feed port 62 is 27 Docket No. PMHA-13050-PCT formed on the sidewall of the first drying room 21 at the upper stream of the direction in which the lignite is to fluidize and is located at roughly the same position as the feed port 31. Thus, the lignite discharged through the 5 lignite discharge port 61 passes through the recirculation line L and is supplied to the first drying room 21 again through the re-feed port 62. [0096] The holding back unit 58 is provided on the second drying room 22 side of the boundary between the 10 first drying room 21 and the second drying room 22 and is provided on the gas diffusing plate 6 that is the bottom surface of the second drying room 22. In other words, the holding back unit 58 is provided on the gas diffusing plate 6 that is the bottom surface of the second drying room 22 15 at the upper stream of the direction in which the lignite is to fluidize. Note that the holding back unit 58 in the second embodiment can be provided at the further upper stream than the circulation opening 46 between the dividing plates 43 at the upper stream of the direction in which the 20 lignite is to fluidize and gas diffusing plate 6 although the holding back unit 58 is provided at the circulation opening 46 as illustrated in FIG. 3. [0097] The foreign matter removing device 57 removes the foreign matter from the lignite passing through the 25 recirculation line L. The foreign matter includes, for example, the metal or wood mixed with the lignite, or the solid of coal formed by the particle condensation. For example, as the foreign matter removing device 57, a cyclone foreign matter removing device that can separate 30 foreign matter using the specific gravity can be applied. However, the foreign matter removing device is not limited to the example. Any devices capable of removing foreign matter can be used. 28 Docket No. PMHA-13050-PCT [0098] Thus, a part of the lignite fluidizing in the first drying room 21 is held back with the holding back unit 58. The held back lignite flows into the lignite discharge port 61 on the recirculation line L. The lignite 5 that has been dried by the initial dry and has flowed out of the first drying room 21 through the lignite discharge port 61 flows into the foreign matter removing device 57. The lignite that has flowed into the foreign matter removing device 57 is separated into foreign matter and the 10 lignite from which the foreign matter has been removed in the foreign matter removing device 57. The separated foreign matter is discharged out of the foreign matter removing device 57. The lignite from which the foreign matter has been removed is supplied toward the re-feed port 15 62 on the recirculation line L. After that, the lignite from which the foreign matter has been removed is supplied to the upper stream in the first drying room 21 through the re-feed port 62. [0099] According to the second embodiment, providing the 20 recirculation line L can discharge the lignite that is currently dried from the first drying room 21 and can supply the lignite to the first drying room 21 again as described above. Thus, both of the lignite dried by the initial dry and the lignite that has not been dried are 25 supplied to the first drying room 21. Supplying the lignite dried by the initial dry can facilitate the dry of the lignite in the first drying room 21. At that time, the foreign matter removing device 57 provided on the recirculation line L can remove the foreign matter from the 30 lignite flowing in the recirculation line L. This can prevent the foreign matter from blocking the recirculation line L. [0100] Further, according to the second embodiment, a 29 Docket No. PMHA-13050-PCT part of the lignite supplied from the first drying room 21 to the second drying room 22 can be held back with the holding back unit 58. This can cause the held back lignite to flow into the lignite discharge port 61 on the 5 recirculation line L. This can increase the amount of lignite flowing into the recirculation line L. Thus, the dry of the lignite in the first drying room 21 can further be facilitated. [0101] Further, according to the second embodiment, the 10 re-feed port 62 is connected to the first drying room 21 so that the lignite passing through the recirculation line L can directly be supplied to the first drying room 21. [0102] Note that the structure illustrated in FIG. 4 can be applied although the re-feed port 62 on the 15 recirculation line L is connected to the first drying room 21 in the second embodiment. FIG. 4 is a schematic structure diagram schematically illustrating a fluid-bed drier according to an exemplary variation. As illustrated in FIG. 4, a recirculation line L includes a re-feed port 20 62 connected to a raw coal banker 121. Thus, the lignite that has been dried by the initial dry and has flowed out of a lignite discharge port 61 on the recirculation line L is separated into foreign matter and the lignite from which the foreign matter has been removed in a foreign matter 25 removing device 57. Then, the lignite from which the foreign matter has been removed is supplied toward the re feed port 62 on the recirculation line L and is supplied to the raw coal banker 121 through the re-feed port 62. Thus, the structure in the exemplary variation can indirectly 30 supply the lignite flowing in the recirculation line L to the first drying room 21 through the raw coal banker 121. [Third Embodiment] [0103] Next, a fluid-bed drier 1C according to the third 30 Docket No. PMHA-13050-PCT embodiment will be described with reference to FIG. 5. FIG. 5 is a schematic structure diagram schematically illustrating a fluid-bed drier according to the third embodiment. Note that, to avoid the overlapping 5 descriptions, the components different from the above mentioned embodiments will be described in the third embodiment. Although the second drying room 22 of the drying furnace 5 has a structure in which the lignite supplied therein is formed into an extruded flow in the 10 fluid-bed drier 1B according to the second embodiment, a second drying room 72 of a drying furnace 5 has a structure in which the lignite supplied therein flows along the direction in which the lignite is to fluidize and, especially, has a structure in which the lignite supplied 15 therein is formed into an overflow. Hereinafter, the second drying room 72 of the drying furnace 5 in the fluid bed drier 1C according to the third embodiment will be described with reference to FIG. 5. [0104] The second drying room 72 is provided with a 20 discharge port 41 from which the lignite is discharged, a steam emission port 42 from which the generated steam is emitted, and a plurality of dividing plates 73. Note that the descriptions of the discharge port 41 and the steam emission port 42 will be omitted because they have the same 25 structures as in the second embodiment. [0105] The dividing plates 73 are positioned at predetermined intervals in the direction in which the lignite is to fluidize. Each of the dividing plates 73 is provided such that the plate surface is perpendicular to 30 the direction in which the lignite is to fluidize. Thus, the dividing plates 43 divide the second drying room 22 into a plurality of drying compartments 75. The drying compartments 75 are formed side by side in the direction in 31 Docket No. PMHA-13050-PCT which the lignite is to fluidize. Each of the dividing plates 73 is connected to a gas diffusing plate 6 of the second drying room 22. The upper end is positioned lower than the upper surface of a fluid bed 3. 5 [0106] Thus, when the lignite dried by the initial dry is supplied from the first drying room 21, the supplied lignite flows into the drying compartment 75 at the start of the upper stream in the second drying room 22 as moving over the dividing plate 73 at the start of the upper stream 10 in the direction in which the lignite is to fluidize. The lignite that has flowed into the drying compartments 75 is formed into a fluid bed 3 by fluidizing with the fluidizing gas supplied through the gas diffusing plate 6. The lignite formed into the fluid bed 3 is dried with the 15 fluidizing gas. Whereas the dried lignite moves upward in the drying compartments 75, the lignite that has not been dried moves downward in the drying compartments 75. The lignite dried in the drying compartment 75 overflows to the drying compartment 75 at the lower stream as moving over 20 the dividing plate 73 at the lower stream in the direction in which the lignite is to fluidize. As described above, the lignite moves as overflowing from a drying compartment 75 at the upper stream to a drying compartment 75 at the lower stream. While passing through all of the drying 25 compartments 75, the lignite is dry by the late dry. [0107] According to the structure in the third embodiment described above, the lignite supplied in the second drying room 72 can be heated and dried while the lignite fluidizes using the overflow along the direction in 30 which the lignite is to fluidize. Thus, the lignite that has not been dried moves downward in the drying compartments 75. The dried lignite moves upward in the drying compartments 75 and fluidizes along the direction in 32 Docket No. PMHA-13050-PCT which the lignite is to fluidize. Thus, the fluid-bed drier 1C in the third embodiment can prevent the discharge of the lignite that has not been dried. This can sufficiently dry the lignite. 5 Reference Signs List [0108] 1A Fluid-bed drier (First embodiment) 1B Fluid-bed drier (Second embodiment) 1C Fluid-bed drier (Third embodiment) 3 Fluid bed 10 5 Drying furnace 6 Gas diffusing plate 11 Chamber room 12 Drying room 21 First drying room 15 22 Second drying room 31 Feed port 33 Heat exchanger tube 41 Discharge port 42 Steam emission port 20 43 Dividing member 45 Drying compartment 46 Circulation opening 47 Flow adjusting unit 51 Panel tube 25 52 Dividing plate 55 Flow dividing plate 57 Foreign matter removing device (Second embodiment) 58 Holding back unit (Second embodiment) 61 Lignite discharge port (Second embodiment) 30 62 Re-feed port (Second embodiment) 72 Second drying room (Third embodiment) 73 Dividing plate (Third embodiment) 75 Drying compartment (Third embodiment) 33 Docket No. PMHA-13050-PCT L Recirculation line 34

Claims

1. A fluid-bed drier comprising: a drying furnace configured to form a fluid bed therein by fluidizing wetting fuel with fluidizing gas; 5 a recirculation line configured to cause the wetting fuel to flow out of the first drying room and to flow into the first drying room again; and a foreign matter removing unit provided on the recirculation line and configured to remove foreign matter 10 from the wetting fuel passing through the recirculation line, wherein the drying furnace is divided into a first drying room in which the wetting fuel is dried by an initial dry and a second drying room in which the wetting fuel supplied from 15 the first drying room is dried by a late dry, the supplied wetting fuel is dried as being formed into a complete mixed flow in the first drying room, and the wetting fuel supplied from the first drying room is dried as being formed into a flow along a direction in 20 which the wetting fuel is to fluidize in the second drying room.

2. The fluid-bed drier according to claim 1, wherein the flow along the direction in which the 25 wetting fuel is to fluidize is an extruded flow.

3. The fluid-bed drier according to claim 1 or 2, wherein the second drying room includes a plurality of drying compartments that is divided in the direction in 30 which the wetting fuel is to fluidize.

4. The fluid-bed drier according to claim 1, wherein the recirculation line includes a fuel 35 discharge port configured to cause the wetting fuel to flow out of the first drying room, and the fuel discharge port is connected to a bottom surface on the first drying room side of a boundary between 5 the first drying room and the second drying room.

5. The fluid-bed drier according to claim 4, wherein the second drying room is provided with a holding back unit on a bottom surface on the second drying 10 room side of the boundary between the first drying room and the second drying room.

6. The fluid-bed drier according to any one of claims 1 to 5, 15 wherein the recirculation line includes a re-feed port configured to cause the wetting fuel that has flowed out of the first drying room to flow into the first drying room, and the re-feed port is connected to the first drying room. 20

7. The fluid-bed drier according to any one of claims 1 to 6, wherein the recirculation line includes a re-feed port configured to cause the wetting fuel that has flowed out of 25 the first drying room to flow into the first drying room, and the re-feed port is connected to a fuel banker configured to store the wetting fuel to be supplied to the first drying room. 30

8. The fluid-bed drier according to any one of claims 1 to 7, wherein a floor area ratio of the first drying room 36 and the second drying room is "the first drying room : the second drying room = 30 to 50% : 70 to 50%".

9. The fluid-bed drier according to any one of claims 1 5 to 8, further comprising: a plurality of dividing members that is provided in the second drying room and is positioned at predetermined intervals in the direction in which the wetting fuel is to fluidize, 10 wherein the dividing members form spaces with a bottom of the second drying room, and each of the dividing members includes a panel tube that is heat exchanger tubes formed into a panel shape. 15

10. The fluid-bed drier according to claim 9, further comprising: a plurality of heat exchanger tubes positioned at an inside of the fluid bed between the dividing members. 20

11. The fluid-bed drier according to any one of claim 9 or 10, wherein the spaces are provided such that the spaces become narrower as being located at lower stream. 25

12. The fluid-bed drier according to any one of claims 9 to 11, wherein the dividing members includes a dividing plate connected to the panel tube, the panel tube is positioned at the inside of the 30 fluid bed, and the dividing plate is positioned at an outside of the fluid bed. 37

13. The fluid-bed drier according to any one of claims 9 to 12, further comprising: a flow adjusting unit that is provided at a space between the dividing member positioned at an end of the 5 lower stream of the direction in which the wetting fuel is to fluidize and the bottom of the second drying room and that is capable of adjusting the flow of the wetting fuel flowing out of the space. 38