JP2012241992A - Drying system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drying system capable of efficiently using an inert gas without igniting brown coal directing to a pulverized coal supply hopper from a fluidized bed drying device.SOLUTION: This drying system includes the fluidized bed drying device 12 capable of discharging an exhaust gas generated in drying brown coal while discharging the dried brown coal, a classifier 13 for classifying the dried brown coal into coarse brown coal and fine brown coal, a coal pulverizer 14 for pulverizing the coarse brown coal to obtain fine brown coal, a dust collector 15 collecting the fine brown coal included in the discharged gas, a fine coal supply hopper 19 storing the fine brown coal classified by the classifier 13, the fine brown coal pulverized by the coal pulverizer 14, and the fine brown coal collected by the dust collector 15, and an inert gas circulating device 20 for circulating the inert gas at least in a part of a brown coal conveying path from the fluidized bed drying device 12 to the fine coal supply hopper 19.

Description

  The present invention relates to a drying system for drying wet fuel such as lignite.

  Conventionally, as such a drying system, a coal pretreatment device is known in which coal is dried and the dried coal is burned in a coke oven and a blast furnace (see, for example, Patent Document 1). This pretreatment device has a fluidized bed drying device that dries the coal and classifies it into coarse coal and fine coal, conveys the classified coarse coal to a coke oven, and converts the classified fine coal into a blast furnace. It is transported to a blast furnace through a pulverized coal production machine.

JP 2002-309265 A

  By the way, when conveying dried coal toward a coke oven and a blast furnace, an inert gas (inert gas) such as nitrogen may be supplied in order to suppress coal ignition. However, if the inert gas is continuously supplied during the drying of the coal, the amount of the supplied inert gas increases, so that it is difficult to use the inert gas efficiently.

  Then, this invention makes it a subject to provide the drying system which can use inert gas efficiently, without igniting the dry fuel which goes to a dry fuel storage part from a drying apparatus.

  The drying system of the present invention discharges the dry fuel obtained by drying the wet fuel, and at the same time, discharges the exhaust gas generated during the drying of the wet fuel, and supplies the dry fuel. Included in exhaust gas, classification device for classifying into granular dry fuel and fine dry fuel, coarse dry fuel supplied, pulverizing supplied dry fuel into fine dry fuel, and fine dry fuel Dust collector that collects fine dry fuel collected, fine dry fuel classified by classifier, fine dry fuel crushed by pulverizer, fine dry fuel collected by dust collector And a dry gas storage unit for circulating the inert gas in at least a part of the dry fuel transport path from the drying device to the dry fuel storage unit.

  According to this configuration, since the inert gas is supplied to the transport path from the drying device to the dry fuel storage unit, the dry fuel is supplied from the drying device to the dry fuel storage unit without igniting the fine dry fuel. be able to. At this time, since the inert gas is circulated in the transport path from the drying device to the dry fuel storage unit, the amount of the inert gas used can be suppressed, so that the inert gas can be used efficiently.

  In this case, the inert gas circulation device is interposed between the pulverizer and the dry fuel storage unit, separates the mixed dry fuel and inert gas supplied from the pulverizer, and stores the separated dry fuel in the dry fuel storage It is preferable to have the 1st solid-gas separation apparatus supplied toward a part, and the 1st gas circulation blower which supplies the inert gas isolate | separated by the 1st solid-gas separation apparatus toward a grinder.

  According to this configuration, the inert gas can be circulated in the transfer path from the pulverizer to the dry fuel storage unit by the first solid-gas separation device and the first gas circulation blower. Thereby, the dry fuel separated from the inert gas can be supplied to the dry fuel reservoir, and the separated inert gas can be supplied from the first solid-gas separation device to the pulverizer.

  In this case, the first cooling device that is provided between the drying device and the classification device and cools the dry fuel discharged from the drying device, and is interposed between the dust collecting device and the dry fuel storage unit, and collects the dust. A second cooling device that cools the dry fuel collected by the device, and a part of the dry fuel transport path from the classification device to the dry fuel storage portion reaches the dry fuel storage portion from the dust collector The inert gas circulation device is interposed in the merged conveyance path and separates the dry fuel and the inert gas in a mixed state and stores the separated dry fuel in the dry fuel storage. And a second gas circulation blower for supplying the inert gas separated by the second solid-gas separation device to the first cooling device and the second cooling device. It is preferable.

  According to this configuration, the second solid-gas separation device and the second gas circulation blower transfer the first cooling device to the dry fuel storage unit via the classifier, and the second cooling device to the dry fuel storage unit. Inert gas can be circulated in the transport path to reach. Thereby, the dry fuel separated from the inert gas can be supplied to the dry fuel reservoir, and the separated inert gas is supplied from the second solid-gas separation device to the first cooling device and the second cooling device. Can do.

  In this case, the second gas circulation blower supplies the inert gas toward the dry fuel conveyance path from the drying apparatus to the first cooling apparatus and the dry fuel conveyance path from the dust collector to the second cooling apparatus. Is preferred.

  According to this configuration, the inert gas separated by the second solid-gas separation device can be supplied to the conveyance path from the drying device to the first cooling device and the conveyance route from the dust collector to the second cooling device. it can.

  According to the drying system of the present invention, the inert gas can be circulated in the transport route of the dry fuel from the drying device to the dry fuel storage unit, so that the dry fuel from the drying device toward the dry fuel storage unit is not ignited, Inert gas can be used efficiently.

FIG. 1 is a schematic configuration diagram of a coal gasification combined power generation facility to which a drying system according to the present embodiment is applied.

  Hereinafter, a drying system according to the present invention will be described with reference to the accompanying drawings. The present invention is not limited to the following examples. In addition, constituent elements in the following embodiments include those that can be easily replaced by those skilled in the art or those that are substantially the same.

  FIG. 1 is a schematic configuration diagram of a coal gasification combined power generation facility to which a drying system according to the present embodiment is applied. An integrated coal gasification combined cycle (IGCC) 100 to which the drying system 1 of the present embodiment is applied employs an air combustion method in which coal gas is generated in a gasification furnace using air as an oxidant, Coal gas after being refined by a gas purifier is supplied to gas turbine equipment as fuel gas to generate electricity. That is, the coal gasification combined power generation facility 100 of the present embodiment is an air combustion type (air blowing) power generation facility. In this case, lignite is used as a wet raw material supplied to the gasifier.

  In this example, lignite was applied as a wet raw material, but low-grade coal including subbituminous coal, peat such as sludge, etc. may be applied as long as the moisture content is high. Even charcoal is applicable. In addition, the wet raw material is not limited to coal such as lignite, but may be biomass used as organic resources derived from renewable organisms. For example, thinned wood, waste wood, driftwood, grass, waste, It is also possible to use sludge, tires, and recycled fuel (pellets and chips) made from these raw materials.

  In this embodiment, as shown in FIG. 1, the coal gasification combined power generation facility 100 includes a coal supply device 111, a drying system 1, a coal gasification furnace 114, a char recovery device 115, a gas purification device 116, and a gas turbine facility 117. , A steam turbine facility 118, a generator 119, and a heat recovery steam generator (HRSG) 120.

  The coal feeder 111 includes a raw coal bunker 121, a coal feeder 122, and a crusher 123. The raw coal bunker 121 can store lignite, and drops a predetermined amount of lignite into the coal feeder 122. The coal feeder 122 transports the brown coal dropped from the raw coal bunker 121 by a conveyor or the like and drops it on the crusher 123. The crusher 123 finely pulverizes the dropped lignite into fine particles.

  The drying system 1 heats and drys the crushed lignite dropped from the coal feeder 111 and supplies the dried lignite to the coal gasifier 114 as fine lignite (pulverized coal). The details of the drying system 1 will be described later.

  The coal gasification furnace 114 is supplied with pulverized coal processed by the drying system 1 and also with char (unburned coal) recovered by the char recovery device 115.

  The coal gasification furnace 114 is connected to a compressed air supply line 141 from a gas turbine facility 117 (compressor 161), and can supply compressed air compressed by the gas turbine facility 117. The air separation device 142 separates and generates nitrogen and oxygen from air in the atmosphere, and a first nitrogen supply line 143 is connected to the coal gasification furnace 114, and the first nitrogen supply line 143 is connected to drying described later. A coal supply line 144 from the pulverized coal supply hopper 19 of the system 1 is connected. The second nitrogen supply line 145 is also connected to the coal gasifier 114, and the char return line 146 from the char recovery device 115 is connected to the second nitrogen supply line 145. Further, the oxygen supply line 147 is connected to the compressed air supply line 141. In this case, nitrogen is used as a carrier gas for coal and char, and oxygen is used as an oxidant.

  The coal gasification furnace 114 is, for example, a spouted bed type gasification furnace, which combusts and gasifies coal, char, air (oxygen) supplied therein, or water vapor as a gasifying agent, and produces carbon dioxide. A combustible gas (product gas, coal gas) containing carbon as a main component is generated, and a gasification reaction takes place using this combustible gas as a gasifying agent. The coal gasification furnace 114 is provided with a foreign matter removing device 148 that removes foreign matter mixed in the pulverized coal. In this case, the coal gasification furnace 114 is not limited to the spouted bed gasification furnace, and may be a fluidized bed gasification furnace or a fixed bed gasification furnace. The coal gasification furnace 114 is provided with a gas generation line 149 for combustible gas toward the char recovery device 115, and can discharge combustible gas containing char. In this case, by providing a gas cooler in the gas generation line 149, the combustible gas may be cooled to a predetermined temperature and then supplied to the char recovery device 115.

  The char recovery device 115 includes a dust collector 151 and a supply hopper 152. In this case, the dust collector 151 is constituted by one or a plurality of bag filters or cyclones, and can separate the char contained in the combustible gas generated in the coal gasification furnace 114. The combustible gas from which the char has been separated is sent to the gas purifier 116 through the gas discharge line 153. The supply hopper 152 stores the char separated from the combustible gas by the dust collector 151. A bin may be disposed between the dust collector 151 and the supply hopper 152, and a plurality of supply hoppers 152 may be connected to the bin. A char return line 146 from the supply hopper 152 is connected to the second nitrogen supply line 145.

The gas purification device 116 performs gas purification by removing impurities such as sulfur compounds and nitrogen compounds from the combustible gas from which the char has been separated by the char recovery device 115. The gas purifier 116 purifies the combustible gas to produce fuel gas, and supplies it to the gas turbine equipment 117. In this gas purifier 116, since the combustible gas from which the char is separated still contains sulfur (H ₂ S), the sulfur is finally removed by removing it with the amine absorbent. Is recovered as gypsum and used effectively.

  The gas turbine equipment 117 includes a compressor 161, a combustor 162, and a turbine 163, and the compressor 161 and the turbine 163 are connected by a rotating shaft 164. The combustor 162 has a compressed air supply line 165 connected from the compressor 161, a fuel gas supply line 166 connected from the gas purification device 116, and a combustion gas supply line 167 connected to the turbine 163. Further, the gas turbine equipment 117 is provided with a compressed air supply line 141 extending from the compressor 161 to the coal gasification furnace 114, and a booster 168 is interposed in the compressed air supply line 141. Therefore, in the combustor 162, the compressed air supplied from the compressor 161 and the fuel gas supplied from the gas purifier 116 are mixed and burned, and the rotating shaft 164 is rotated by the generated combustion gas in the turbine 163. By doing so, the generator 119 can be driven.

  The steam turbine equipment 118 has a turbine 169 connected to the rotating shaft 164 in the gas turbine equipment 117, and the generator 119 is connected to the base end portion of the rotating shaft 164. The exhaust heat recovery boiler 120 is provided in the exhaust gas line 170 from the gas turbine equipment 117 (the turbine 163), and generates steam by exchanging heat between air and high-temperature exhaust gas. Therefore, the exhaust heat recovery boiler 120 is provided with a steam supply line 171 and a steam recovery line 172 between the turbine 169 of the steam turbine equipment 118, and a condenser 173 is provided in the steam recovery line 172. Yes. Therefore, in the steam turbine equipment 118, the turbine 169 is driven by the steam supplied from the exhaust heat recovery boiler 120, and the generator 119 can be driven by rotating the rotating shaft 164.

  The exhaust gas from which heat has been recovered by the exhaust heat recovery boiler 120 is removed of harmful substances by the gas purification device 174, and the purified exhaust gas is discharged from the chimney 175 to the atmosphere.

  Here, the operation | movement of the coal gasification combined cycle power generation equipment 100 of a present Example is demonstrated.

  In the coal gasification combined power generation facility 100 of the present embodiment, raw coal (brown coal) is stored in the raw coal bunker 121 by the coal feeder 111, and the lignite in the raw coal bunker 121 is crushed by the coal feeder 122. It is dropped to 123, where it is crushed to a predetermined size. The crushed lignite is supplied to the drying system 1. The drying system 1 uses the pulverized lignite as pulverized coal, and the pulverized coal is supplied to the coal gasifier 114 through the first nitrogen supply line 143 by nitrogen supplied from the air separation device 142. Further, the char recovered by the char recovery device 115 described later is supplied to the coal gasifier 114 through the second nitrogen supply line 145 by nitrogen supplied from the air separation device 142. Further, compressed air extracted from a gas turbine facility 117 described later is boosted by a booster 168 and then supplied to the coal gasifier 114 through the compressed air supply line 141 together with oxygen supplied from the air separation device 142.

  In the coal gasification furnace 114, the supplied pulverized coal and char are combusted by compressed air (oxygen), and the pulverized coal and char are gasified, so that combustible gas (coal gas) mainly containing carbon dioxide is obtained. Can be generated. This combustible gas is discharged from the coal gasifier 114 through the gas generation line 149 and sent to the char recovery device 115.

  In the char recovery device 115, the combustible gas is first supplied to the dust collector 151, and the dust collector 151 separates the char contained in the combustible gas. The combustible gas from which the char has been separated is sent to the gas purifier 116 through the gas discharge line 153. On the other hand, the fine char separated from the combustible gas is deposited on the supply hopper 152, returned to the coal gasifier 114 through the char return line 146, and recycled.

  The combustible gas from which the char has been separated by the char recovery device 115 is gas purified by removing impurities such as sulfur compounds and nitrogen compounds by the gas purification device 116 to produce fuel gas. In the gas turbine equipment 117, when the compressor 161 generates compressed air and supplies the compressed air to the combustor 162, the combustor 162 is supplied from the compressed air supplied from the compressor 161 and the gas purifier 116. Combustion gas is generated by mixing with fuel gas and combusting, and the turbine 163 is driven by this combustion gas, so that the generator 119 is driven via the rotating shaft 164 to generate power.

  The exhaust gas discharged from the turbine 163 in the gas turbine facility 117 generates steam by exchanging heat with air in the exhaust heat recovery boiler 120, and supplies the generated steam to the steam turbine facility 118. . In the steam turbine equipment 118, the turbine 169 is driven by the steam supplied from the exhaust heat recovery boiler 120, whereby the generator 119 can be driven via the rotating shaft 164 to generate power.

  Thereafter, in the gas purification device 174, harmful substances in the exhaust gas discharged from the exhaust heat recovery boiler 120 are removed, and the purified exhaust gas is released from the chimney 175 to the atmosphere.

  Next, with reference to FIG. 1, the drying system 1 in the coal gasification combined cycle facility 100 mentioned above is demonstrated in detail. As described above, the drying system 1 heats and dries lignite, which is coal having a high water content, supplied from the coal supply device 111 to pulverized coal, and supplies the pulverized coal to the coal gasifier 114.

  The drying system 1 includes a fluidized bed dryer (dryer) 12, a classifier (classifier) 13, a pulverized coal machine (pulverizer) 14, a dust collector 15, and a first cooler (first cooler). ) 16, a second cooler (second cooling device) 17, a pulverized coal bag filter 18, a pulverized coal supply hopper (dry fuel storage unit) 19, and an inert gas circulation device 20.

  The fluidized-bed drying device 12 supplies drying steam such as superheated steam to the lignite charged by the coal feeder 111, thereby heating and drying the lignite while flowing, thereby removing moisture contained in the lignite. It is. The fluidized bed drying apparatus 12 discharges the lignite after drying as dry charcoal and discharges exhaust gas generated when the lignite is dried.

  The first cooler 16 is connected to the fluidized bed drying device 12 via the first cooling line 81 and cools the lignite (dry coal) discharged from the fluidized bed drying device 12. The inert gas is supplied to the first cooling line 81 and the first cooler 16 by the inert gas circulation device 20. The inert gas is an inert gas, and nitrogen is used in this embodiment. Thereby, in the 1st cooling line 81 and the 1st cooler 16, the ignition of lignite is suppressed. The first cooler 16 discharges the lignite after cooling together with the inert gas.

  The classifier 13 is connected to the first cooler 16 and classifies the lignite after cooling supplied from the first cooler 16. As the classifier 13, for example, a cyclone type is used, and the supplied lignite is classified into coarse lignite and fine lignite (pulverized coal). The classifier 13 supplies coarse lignite to the pulverized coal machine 14 while supplying fine lignite to the pulverized coal bug filter 18.

  The pulverized coal machine 14 is a coal pulverizer such as a mill, and pulverized coarse lignite supplied from the classifier 13 into fine particles to produce pulverized coal. That is, when the coarse lignite is supplied from the classifier 13, the pulverized coal machine 14 pulverizes the coarse lignite into fine lignite. The pulverized coal after pulverization is supplied to the pulverized coal bag filter 18. The pulverized coal machine 14 is supplied with inert gas by an inert gas circulation device 20. Thereby, in the pulverized coal machine 14, the ignition of lignite is suppressed. The pulverized coal machine 14 discharges the pulverized lignite together with the inert gas.

  The dust collector 15 includes a dry coal cyclone 133 and a dry coal electric dust collector 134. The dry coal cyclone 133 is connected to the fluidized bed dryer 12 and separates fine lignite contained in the exhaust gas discharged from the fluidized bed dryer 12. The dry coal cyclone 133 supplies the separated lignite to the second cooler 17, and supplies the exhaust gas after the lignite separation to the dry coal electric machine dust collector 134.

  The dry coal electric dust collector 134 is connected to the dry coal cyclone 133, and further separates the fine lignite contained in the exhaust gas discharged from the dry coal electric dust collector 134. The dry coal electric dust collector 134 supplies the separated lignite toward the second cooler 17. The exhaust gas from which the brown coal is separated by the dry coal electrostatic precipitator 134 may be supplied to the fluidized bed drying device 12 as drying steam after being compressed by the steam compressor 135.

  The second cooler 17 is connected to the dry coal cyclone 133 and the dry coal electric dust collector 134 via the second cooling line 86, respectively, and the lignite (pulverized coal) discharged from the dry coal cyclone 133 and the dry coal electric dust collector 134. ) Is cooling. The inert gas is supplied to the second cooling line 86 and the second cooler 17 by the inert gas circulation device 20. Thereby, in the 2nd cooling line 86 and the 2nd cooler 17, the ignition of lignite is suppressed. Moreover, the 2nd cooler 17 discharges | emits the lignite after cooling toward the pulverized coal bag filter 18 with inert gas.

  The pulverized coal bag filter 18 is connected to the pulverized coal machine 14 via the first pulverized coal supply line 82, and is connected to the second cooler 17 via the second pulverized coal supply line 83. Further, the second pulverized coal supply line 83 is connected to the classifier 13 via the third pulverized coal supply line 84. That is, a part of the downstream side in the conveyance direction of the second pulverized coal supply line 83 includes a conveyance path for conveying pulverized coal from the second cooler 17 to the pulverized coal bag filter 18, and a pulverized coal bag filter 18 from the classifier 13. It becomes the confluence | merging conveyance path | route 83a with which the conveyance path | route which conveys pulverized coal to. The pulverized coal bag filter 18 separates the pulverized coal supplied from the classifier 13, the pulverized coal machine 14, and the second cooler 17, and supplies the pulverized coal to the pulverized coal supply hopper 19. The pulverized coal supply hopper 19 stores the pulverized coal separated by the pulverized coal bag filter 18.

  Therefore, the lignite dried by the fluidized bed drying device 12 is supplied to the first cooler 16 and cooled, and then supplied from the first cooler 16 to the classifier 13. The lignite supplied to the classifier 13 is classified into coarse lignite and fine lignite, and the classified coarse lignite is supplied to the pulverized coal machine 14, while the classified fine lignite is The pulverized coal bag filter 18 is supplied. The coarse lignite supplied to the pulverized coal machine 14 is pulverized into fine lignite by the pulverized coal machine 14 and then supplied toward the pulverized coal bug filter 18.

  On the other hand, fine lignite in the exhaust gas discharged from the fluidized bed drying device 12 is supplied to the dry coal cyclone 133 and the dry coal electric dust collector 134 and collected, and then supplied to the second cooler 17. To be cooled. The cooled fine lignite is supplied to the pulverized coal bag filter 18.

  The inert gas circulation device 20 circulates the inert gas in the lignite conveying path from the fluidized bed drying device 12 to the pulverized coal bag filter 18. The inert gas circulation device 20 includes a first solid gas separation device 31, a second solid gas separation device 32, a first gas circulation blower 33, and a second gas circulation blower 34.

  The first solid-gas separation device 31 is a so-called cyclone type dust collector, and has the same configuration as that of the dry coal cyclone 133. The first solid-gas separation device 31 is provided in the first pulverized coal supply line 82 and separates the mixed lignite and inert gas that pass through the first pulverized coal supply line 82. The first solid-gas separation device 31 supplies the separated lignite toward the pulverized coal bag filter 18. On the other hand, the first solid-gas separation device 31 supplies the inert gas after the lignite separation toward the pulverized coal machine 14 via the first gas supply line 91.

  The first gas circulation blower 33 is interposed in the first gas supply line 91 and supplies the inert gas discharged from the first solid-gas separation device 31 toward the pulverized coal machine 14. Thus, the inert gas flows from the pulverized coal machine 14 through the first pulverized coal supply line 82 to the first solid-gas separation device 31 and from the first solid-gas separation device 31 through the first gas supply line 91 to the pulverized powder. It flows into the charcoal machine 14. That is, the inert gas circulates between the pulverized coal machine 14 and the first solid-gas separation device 31.

  Similar to the first solid-gas separation device 31, the second solid-gas separation device 32 is a cyclone type dust collector. The second solid-gas separation device 32 is interposed in the merging and conveying path 83 a of the second pulverized coal supply line 83. The second solid-gas separation device 32 separates the lignite and the inert gas in a mixed state that pass through the confluence conveyance path 83a. The second solid-gas separation device 32 supplies the separated lignite toward the pulverized coal bag filter 18. On the other hand, the second solid-gas separation device 32 converts the inert gas after lignite separation into the first cooler 16, the second cooler 17, the first cooling line 81, and the second cooling via the second gas supply line 92. Supply toward line 86.

  The second gas circulation blower 34 is provided in the second gas supply line 92 and converts the inert gas discharged from the second solid-gas separation device 32 into the first cooler 16, the second cooler 17, and the first cooling. Supplying toward the line 81 and the second cooling line 86. Thus, the inert gas flows from the first cooler 16 to the classifier 13 and then flows from the classifier 13 to the third pulverized coal supply line 84. Thereafter, the inert gas merges from the third pulverized coal supply line 84 to the second pulverized coal supply line 83 and then flows into the second solid-gas separation device 32. On the other hand, the inert gas flows from the second cooler 17 to the second pulverized coal supply line 83 and then flows into the second solid-gas separation device 32. The inert gas flowing into the second solid / gas separation device 32 is supplied from the second solid / gas separation device 32 toward the first cooler 16, the second cooler 17, the first cooling line 81, and the second cooling line 86. That is, the inert gas circulates between the first cooler 16, the second cooler 17, the first cooling line 81, the second cooling line 86, and the second solid-gas separation device 32.

  As described above, according to the configuration of the present embodiment, the inert gas circulation device 20 can circulate the inert gas in at least a part of the conveyance path from the fluidized bed drying device 12 to the pulverized coal supply hopper 19, The lignite can be supplied from the fluidized bed dryer 12 to the pulverized coal supply hopper 19 without igniting the fine lignite. At this time, since the inert gas is circulated by the inert gas circulation device 20, the amount of the inert gas used can be suppressed, so that the inert gas can be used efficiently.

  Further, according to the configuration of the present embodiment, the inert gas can be circulated between the pulverized coal machine 14 and the first solid-gas separation device 31 by the first solid-gas separation device 31 and the first gas circulation blower 33. it can. Thereby, the lignite separated from the inert gas can be supplied toward the pulverized coal supply hopper 19, and the inert gas after separation can be supplied from the first solid-gas separation device 31 toward the pulverized coal machine 14. .

  Further, according to the configuration of the present embodiment, the first cooler 16, the second cooler 17, the first cooling line 81, and the second cooling line 86 are performed by the second solid-gas separation device 32 and the second gas circulation blower 34. And the inert gas can be circulated between the second solid-gas separation device 32. Thereby, the lignite separated from the inert gas can be supplied to the pulverized coal supply hopper 19, and the inert gas after separation is supplied from the second solid-gas separation device 32 to the first cooler 16, the second cooler 17, It can be supplied toward the first cooling line 81 and the second cooling line 86.

DESCRIPTION OF SYMBOLS 1 Drying system 12 Fluidized bed drying apparatus 13 Classifier 14 Pulverized coal machine 15 Dust collector 16 1st cooler 17 2nd cooler 18 Pulverized coal bag filter 19 Pulverized coal supply hopper 20 Inert gas circulation device 31 1st solid-gas separation apparatus 32 2nd solid-gas separation device 33 1st gas circulation blower 34 2nd gas circulation blower 81 1st cooling line 82 1st pulverized coal supply line 83 2nd pulverized coal supply line 83a Confluence conveyance path 84 3rd pulverized coal supply line 86 Second cooling line 91 First gas supply line 92 Second gas supply line

Claims (4)

A drying device that discharges the dry fuel obtained by drying the wet fuel and can discharge exhaust gas generated when the wet fuel is dried;
A classifier for supplying the dry fuel, and classifying the supplied dry fuel into the coarse dry fuel and the fine dry fuel;
A pulverizer supplied with the coarse dry fuel, pulverizing the supplied dry fuel into fine dry fuel;
A dust collector that collects the fine dry fuel contained in the exhaust gas;
A dry fuel storage unit that stores the fine dry fuel classified by the classifier, the fine dry fuel pulverized by the pulverizer, and the fine dry fuel collected by the dust collector When,
An drying system comprising: an inert gas circulation device that circulates an inert gas in at least a part of a transport path of the dry fuel from the drying device to the dry fuel storage unit. The inert gas circulation device is
The mixed dry fuel and the inert gas, which are interposed between the pulverizer and the dry fuel storage unit and are supplied from the pulverizer, are separated, and the dry fuel after separation is separated from the dry fuel storage unit A first solid-gas separation device for feeding toward the
The drying system according to claim 1, further comprising: a first gas circulation blower that supplies the inert gas separated by the first solid-gas separation device to the pulverizer. A first cooling device that is provided between the drying device and the classifying device and that cools the dry fuel discharged from the drying device;
A second cooling device that is interposed between the dust collector and the dry fuel reservoir and cools the dry fuel collected by the dust collector;
A part of the dry fuel transfer path from the classifier to the dry fuel storage part is a confluence transfer path that merges with the dry fuel transfer path from the dust collector to the dry fuel storage part. ,
The inert gas circulation device is
A second solid-gas separation device that is interposed in the merged conveyance path, separates the dry fuel and the inert gas in a mixed state, and supplies the dry fuel after separation toward the dry fuel storage unit;
The second gas circulation blower that supplies the inert gas separated by the second solid-gas separation device toward the first cooling device and the second cooling device. The drying system according to 1 or 2. The second gas circulation blower is
The inert gas is supplied to a transport route of the dry fuel from the drying device to the first cooling device and a transport route of the dry fuel from the dust collecting device to the second cooling device. The drying system according to claim 3.

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