JP5916426B2 - Fluidized bed drying apparatus, gasification combined power generation facility, and drying method - Google Patents

Description

  The present invention relates to a fluidized bed drying apparatus, a gasification combined power generation facility, and a drying method for drying while flowing wet fuel such as lignite.

  Conventionally, as such a fluidized bed drying apparatus, a dryer main body, a planar perforated plate that partitions the interior of the dryer main body into an upper flow chamber and a lower air box, and the flow chamber as a front flow chamber And a partition wall partitioning into a rear fluid chamber are known (for example, see Patent Document 1). In this stirring heat transfer type fluid drying apparatus, the front fluid chamber is provided with a hollow rotating shaft disposed in the longitudinal direction and a stirring heat transfer member attached to the hollow rotating shaft, and the hollow rotating shaft is the center. As the stirring heat transfer member rotates, the material supplied to the front fluid chamber is mixed and heated.

Japanese Patent Laid-Open No. 4-13086

  By the way, in a fluidized bed drying apparatus that heats wet fuel such as lignite while flowing in the flow direction with a fluidized gas, the moisture content of the wet fuel on the supply side (upstream side) in the flow direction and the discharge side (downstream) in the flow direction The moisture content of the wet fuel is different. In other words, the wet fuel on the upstream side in the flow direction has just been supplied to the fluidized bed drying device, so the moisture content is high, while the wet fuel on the downstream side in the flow direction becomes the wet fuel on the upstream side in the flow direction. In comparison, the moisture content is low because of heating for a long time in the fluidized bed drying apparatus. For this reason, since the moisture content of the wet fuel is high on the upstream side in the flow direction of the fluidized bed drying apparatus, the wet fuel tends to aggregate and easily adhere to the furnace wall or the bottom of the furnace. Moreover, when the heat transfer tube is provided inside, the wet fuel tends to adhere to the heat transfer tube. As a result, deposits may be generated due to the adhesion of the wet fuel, or agglomerates may be generated due to the aggregation of the wet fuel, which may cause a flow failure.

  Therefore, an object of the present invention is to provide a fluidized bed drying apparatus, a gasification combined power generation facility, and a drying method capable of suitably flowing wet fuel.

  The fluidized bed drying apparatus according to the present invention includes a drying furnace in which a fluidized bed is formed by flowing the supplied wet fuel along the flow direction by the fluidizing gas, and a drying furnace upstream of the flow direction. A fuel inlet for introducing wet fuel into the drying furnace, a fuel outlet for discharging the wet fuel dried in the drying furnace at the downstream of the flow direction, and a fluidized bed And a reverse flow supply unit for supplying wet fuel by flowing backward from the downstream side in the flow direction toward the upstream side.

  According to this configuration, a part of the wet fuel on the downstream side in the flow direction can be supplied to the upstream side in the flow direction by the backflow supply unit. For this reason, the inside of the drying furnace on the upstream side in the flow direction is supplied with wet fuel having a lower moisture content than that on the upstream side in the flow direction. Thus, the wet fuel flowing in the drying furnace on the upstream side in the flow direction is supplied with the low moisture content from the downstream side in the flow direction even if the wet fuel is supplied from the fuel input port. Water content is reduced. Therefore, when the moisture content of the wet fuel is lowered, the wet fuel is less likely to agglomerate and adhere less. Thereby, generation | occurrence | production of the deposit by adhesion of wet fuel can be suppressed, and generation | occurrence | production of the agglomerate by aggregation of wet fuel can be suppressed, Therefore Wet fuel can be made to flow suitably.

  In this case, the interior of the drying furnace is divided into a plurality of drying chambers along the flow direction, and the backflow supply unit flows back from the drying chamber downstream in the flow direction toward the drying chamber upstream in the flow direction. It is preferable to supply the wet fuel while allowing the fuel to flow.

  According to this configuration, part of the wet fuel in the downstream drying chamber can be supplied to the upstream drying chamber by the backflow supply unit. For this reason, the wet fuel having a lower water content than the upstream drying chamber is supplied to the inside of the upstream drying chamber. As a result, the wet fuel flowing in the upstream drying chamber is reduced in moisture content because the wet fuel having a low water content is supplied from the downstream drying chamber even when the wet fuel is supplied from the fuel inlet. . Therefore, when the moisture content of the wet fuel is lowered, the wet fuel is less likely to agglomerate and adhere less. Thereby, in the upstream drying chamber, the generation of deposits due to the adhesion of the wet fuel can be suppressed, and the generation of aggregates due to the aggregation of the wet fuel can be suppressed, so that the wet fuel can be suitably flowed.

  In this case, the plurality of drying chambers are three drying chambers including a drying chamber on the upstream side in the flow direction, a drying chamber on the midstream side in the flow direction, and a drying chamber on the downstream side in the flow direction. The unit supplies wet fuel while backflowing from the downstream drying chamber in the flow direction toward the intermediate drying chamber in the flow direction, and from the drying chamber downstream in the flow direction to the upstream drying chamber in the flow direction. It is preferable to supply the wet fuel while making it flow backward.

  According to this configuration, the wet fuel in the downstream drying chamber can be supplied to the intermediate drying chamber and the upstream drying chamber by the backflow supply unit. As a result, the moisture content of the wet fuel in the drying chamber on the middle stream side and the drying chamber on the upstream side can be reduced, so that the wet fuel is less likely to agglomerate and adhere less. Therefore, in the middle drying chamber and the upstream drying chamber, the generation of deposits due to the adhesion of the wet fuel can be suppressed, and the generation of agglomerates due to the aggregation of the wet fuel can be suppressed. Can be made.

  In this case, the backflow supply unit preferably has a screw feeder that supplies wet fuel from the downstream side to the upstream side in the flow direction.

  According to this configuration, by providing the screw feeder inside the fluidized bed, it is possible to supply wet fuel with a simple configuration from the downstream side to the upstream side in the flow direction.

  In this case, it is preferable that the screw feeder is provided over the flow direction and is provided below the fluidized bed in the vertical direction.

  According to this configuration, the screw feeder can supply wet fuel from the downstream side to the upstream side below the fluidized bed. For this reason, since it is possible to supply the wet fuel on the downstream side toward the wet fuel on the upstream side that is easily deposited on the lower side of the fluidized bed, it is possible to suitably suppress the occurrence of poor flow.

  In this case, it is preferable that the screw feeder is provided over the flow direction and is provided above the fluidized bed in the vertical direction.

  According to this configuration, since the flow of the wet fuel on the lower side of the fluidized bed is not inhibited by the screw feeder, the wet fuel on the downstream side is directed upstream while the wet fuel is preferably flowed in the flow direction. Can be supplied.

  In this case, the fuel inlet is provided on the upper side in the vertical direction of the drying furnace, the fuel outlet is provided on the lower side in the vertical direction of the drying furnace, and the screw feeder has an upstream end in the flow direction. Preferably, the fluidized bed is provided on the upper side in the vertical direction and the downstream end of the fluidized bed is provided on the lower side in the vertical direction of the fluidized bed, so that the fluidized bed is provided obliquely across the fluidized direction.

  According to this configuration, the screw feeder can supply wet fuel around the fuel discharge port toward the fuel input port. For this reason, the screw feeder can supply the wet fuel having a lower water content near the fuel discharge port toward the wet fuel having a higher water content immediately after the fuel is supplied. The water content of can be suitably reduced.

  A gasification combined power generation facility of the present invention includes the above fluidized bed drying apparatus, a gasification furnace that processes the wet fuel after drying supplied from the fluidized bed drying apparatus and converts it into gasification gas, and gasification gas A gas turbine operated as fuel, a steam turbine operated by steam generated by an exhaust heat recovery boiler that introduces turbine exhaust gas from the gas turbine, and a generator connected to the gas turbine and the steam turbine It is characterized by.

  According to this structure, the wet fuel suitably flowed and dried in the fluidized bed drying apparatus can be supplied to the gasification furnace.

  The drying method of the present invention is a drying method in which wet fuel is dried while flowing the supplied wet fuel along the flow direction with a fluidizing gas, and is wet inside the fluidized bed and downstream in the flow direction. It is characterized in that a part of the fuel is supplied by flowing backward to the upstream side in the flow direction.

  According to this configuration, part of the wet fuel on the downstream side in the flow direction can be supplied to the upstream side in the flow direction. For this reason, the wet fuel having a lower water content than the upstream side in the flow direction is supplied to the wet fuel on the upstream side in the flow direction. Thereby, the wet fuel on the upstream side in the flow direction is supplied with the wet fuel having a low water content from the downstream side in the flow direction, so that the water content is lowered. Therefore, when the moisture content of the wet fuel is lowered, the wet fuel is less likely to agglomerate and adhere less. Thereby, generation | occurrence | production of the deposit by adhesion of wet fuel can be suppressed, and generation | occurrence | production of the agglomerate by aggregation of wet fuel can be suppressed, Therefore Wet fuel can be made to flow suitably.

  According to the fluidized bed drying apparatus and the drying method of the present invention, the moisture content of the wet fuel on the upstream side in the flow direction can be reduced, so that accumulation and agglomeration of the wet fuel can be suppressed, and the wet fuel can be suitably flowed. Can do.

FIG. 1 is a schematic configuration diagram of a coal gasification combined power generation facility to which a fluidized bed drying apparatus according to a first embodiment is applied. FIG. 2 is a schematic configuration diagram schematically illustrating the fluidized bed drying apparatus according to the first embodiment. FIG. 3 is a schematic configuration diagram schematically illustrating the fluidized bed drying apparatus according to the second embodiment. FIG. 4 is a schematic configuration diagram schematically illustrating the fluidized bed drying apparatus according to the third embodiment. FIG. 5 is a schematic configuration diagram schematically illustrating the fluidized bed drying apparatus according to the fourth embodiment. FIG. 6 is a plan view schematically illustrating the fluidized bed drying apparatus according to the fourth embodiment.

  Hereinafter, a fluidized bed drying apparatus and a drying method 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 fluidized bed drying apparatus according to a first embodiment is applied. An integrated coal gasification combined cycle (IGCC) 100 to which the fluidized bed drying apparatus 1 of Example 1 is applied employs an air combustion system that generates coal gas in a gasification furnace using air as an oxidant. The coal gas refined by the gas purifier is supplied as fuel gas to the gas turbine equipment for power generation. That is, the combined coal gasification combined power generation facility 100 according to the first embodiment is an air combustion type (air blowing) power generation facility. In this case, lignite is used as wet fuel supplied to the gasifier.

  In Example 1, lignite was used as the wet fuel, but low-grade coal including sub-bituminous 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 fuel 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 Example 1, as shown in FIG. 1, the coal gasification combined power generation facility 100 includes a coal supply device 111, a fluidized bed drying device 1, a pulverized coal machine (mill) 113, a coal gasification furnace 114, and a char recovery device 115. , Gas refiner 116, gas turbine facility 117, steam turbine facility 118, generator 119, and exhaust 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.

  Although details will be described later, the fluidized bed drying apparatus 1 removes moisture contained in the lignite by drying the lignite input from the coal supply apparatus 111 while flowing it with a fluidizing gas such as superheated steam. . The fluidized bed drying apparatus 1 is connected to a cooler 131 for cooling the discharged dried lignite (dry coal). The cooler 131 is connected to a dry charcoal bunker 132 for storing cooled dry charcoal. In addition, a dry coal cyclone 133 and a dry coal electric dust collector 134 are connected to the fluidized bed dryer 1 as a dust collector 139 for separating dry coal particles from exhaust gas discharged to the outside. The dry coal particles separated from the exhaust gas in the dry coal cyclone 133 and the dry coal electrostatic precipitator 134 are stored in the dry coal bunker 132. The exhaust gas from which the dry coal is separated by the dry coal electrostatic precipitator 134 is compressed by the vapor compressor 135 and then used as various heat sources.

  The pulverized coal machine 113 is a coal pulverizer, and pulverized coal (dried coal) dried by the fluidized bed drying apparatus 1 is pulverized into fine particles to produce pulverized coal. In other words, when the dry coal stored in the dry coal bunker 132 is dropped by the coal feeder 136, the pulverized coal machine 113 converts the dry coal into pulverized coal having a predetermined particle size or less. The pulverized coal after being pulverized by the pulverized coal machine 113 is separated from the conveying gas by the pulverized coal bag filters 137a and 137b and stored in the pulverized coal supply hoppers 138a and 138b.

  The coal gasifier 114 is supplied with pulverized coal processed by the pulverized coal machine 113 and supplied 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. A first nitrogen supply line 143 is connected to the coal gasifier 114, and a pulverized coal supply hopper is connected to the first nitrogen supply line 143. Charging lines 144a and 144b from 138a and 138b are 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 that combusts and gasifies coal, char, oxidant (oxygen) supplied therein, or water vapor as a gasifying agent, A combustible gas (generated gas, coal gas) containing carbon dioxide as a main component is generated, and a gasification reaction takes place using this combustible gas as a gasifying agent. Note that the coal gasification furnace 114 is provided with a foreign matter removing device 148 that removes foreign matter mixed with 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 fine 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 freed 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 action | operation of the coal gasification combined cycle power generation equipment 100 of Example 1 is demonstrated.

  In the combined coal gasification combined power generation facility 100 of the first 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 heated and dried by the fluidized bed drying apparatus 1, cooled by the cooler 131, and stored in the dry coal bunker 132. Further, the steam taken out from the upper part of the fluidized bed drying apparatus 1 is used as various heat sources after the dry coal particles are separated by the dry coal cyclone 133 and the dry coal electric dust collector 134 and compressed by the vapor compressor 135. The On the other hand, dry coal particles separated from the steam are stored in the dry coal bunker 132.

  The dry coal stored in the dry coal bunker 132 is supplied to the pulverized coal machine 113 by the coal feeder 136, where it is pulverized into fine particles to produce pulverized coal, and the pulverized coal bag filters 137a and 137b are used. And stored in pulverized coal supply hoppers 138a and 138b. The pulverized coal stored in the pulverized coal supply hoppers 138 a and 138 b is supplied to the coal gasification furnace 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.

  Hereinafter, the fluidized bed drying apparatus 1 in the coal gasification combined power generation facility 100 described above will be described in detail. FIG. 2 is a schematic configuration diagram schematically illustrating the fluidized bed drying apparatus according to the first embodiment. The fluidized-bed drying apparatus 1 of Example 1 heat-drys the lignite which is coal with a high water content, making it flow with a fluidization gas.

  As shown in FIG. 2, the fluidized bed drying apparatus 1 includes a drying furnace 5 in which lignite is supplied and a gas dispersion plate 6 provided inside the drying furnace 5. The drying furnace 5 is formed in a rectangular box shape. The gas distribution plate 6 divides the space inside the drying furnace 5 into a wind chamber 11 positioned on the lower side in the vertical direction (lower side in the drawing) and a drying chamber 12 positioned on the upper side in the vertical direction (upper side in the drawing). ing. A number of through holes are formed in the gas dispersion plate 6, and fluidized gas such as steam is introduced into the wind chamber 11. As the gas dispersion plate 6, in addition to a plate in which a large number of through holes are formed, a plate in which holes are formed, a plate in which a nozzle is attached to the top of the wind chamber 11, or the like may be applied.

  In the drying chamber 12 of the drying furnace 5, a lignite input port (fuel input port) 31 for charging lignite, a dry coal discharge port (fuel discharge port) 41 for discharging dry coal obtained by heating and drying lignite, and a fluidized gas A gas discharge port 42 for discharging generated steam as an exhaust gas and a screw feeder 45 are provided.

  The brown coal charging port 31 is formed on the upper side in the vertical direction on one end side (the left side in the drawing) of the drying chamber 12. A coal supply device 111 is connected to the lignite charging unit 31, and the lignite supplied from the coal supply device 111 is supplied to the drying chamber 12.

  The dry coal discharge port 41 is formed on the lower side in the vertical direction on the other end side (the right side in the drawing) of the drying chamber 12. The brown coal dried in the drying chamber 12 is discharged as dry coal from the dry coal discharge port 41, and the discharged dry coal is supplied toward the cooler 131 described above.

  The gas discharge port 42 is formed on the upper side in the vertical direction on the other end side of the drying chamber 12. The gas discharge port 42 discharges the generated steam generated from the drying chamber 12 together with the fluidized gas supplied to the drying chamber 12 when the lignite is dried. The fluidized gas and generated steam discharged from the gas discharge port 42 are supplied toward the dust collector 139 described above.

  Therefore, the lignite supplied to the drying chamber 12 via the lignite charging port 31 flows by the fluidized gas supplied via the gas dispersion plate 6 to form the fluidized bed 3 in the drying chamber 12. The free board portion F is formed above the fluidized bed 3. The flow direction of the fluidized bed 3 formed in the drying chamber 12 is a direction from one end side to the other end side of the drying chamber 12. The supplied lignite is dried while flowing along the flow direction, so that moisture contained in the lignite becomes generated steam and is discharged from the gas discharge port 42 together with the fluidizing gas. The lignite from which moisture has been removed and which has flowed to the other end of the drying chamber 12 is discharged from the dry charcoal discharge port 41 as dry charcoal.

  The screw feeder 45 functions as a backflow supply unit that supplies a part of the lignite on the downstream side in the flow direction so as to flow back to the upstream side in the flow direction. The screw feeder 45 includes a motor 51 serving as a drive source, a rotating shaft 52 connected to the motor 51, a screw portion 53 attached to the rotating shaft 52, and an outer cylinder 54 covering the screw portion 53. .

  The motor 51 is provided outside the drying furnace 5 and rotates the rotating shaft 52. The rotating shaft 52 is provided so as to penetrate the inside and outside of the drying furnace 5, and rotates the attached screw portion 53. The rotating shaft 52 is provided horizontally across the flow direction, and is provided on the lower side of the fluidized bed 3 in the vertical direction. The screw part 53 rotates when the motor 51 rotates the rotating shaft 52. The inside of the outer cylinder 54 is a reverse flow supply path 55, in which the lignite flows from the downstream side to the upstream side in the flow direction. A rotating shaft 52 and a screw portion 53 are stored inside the outer cylinder 54.

  The screw feeder 45 is provided on the lower side of the fluidized bed 3 in the vertical direction. That is, the screw feeder 45 is provided in the vicinity of the gas dispersion plate 6 and is provided away from the free board portion F.

  Therefore, when the rotating shaft 52 is rotated by the motor 51, the screw feeder 45 rotates the screw portion 53, so that a part of the lignite on the downstream side in the flow direction of the drying chamber 12 on the lower side of the fluidized bed 3. Is taken into the inside from the downstream end of the outer cylinder 54. The brown coal taken in the outer cylinder 54 flows from the downstream side in the flow direction of the backflow supply path 55 toward the upstream side as the screw portion 53 rotates. And the brown coal which distribute | circulated the backflow supply path 55 is discharged | emitted from the upstream edge part of the outer cylinder 54 outside, and is supplied to the drying chamber 12 in the downward direction of the fluidized bed 3, and the upstream of a flow direction. .

  As described above, according to the configuration of the first embodiment, a part of the brown coal on the downstream side of the drying chamber 12 can be supplied to the upstream side of the drying chamber 12 by the screw feeder 45. For this reason, lignite having a lower moisture content than the upstream side is supplied to the upstream side of the drying chamber 12. Thereby, even if lignite is supplied from the lignite charging port 31 to the upstream side of the drying chamber 12, lignite having a low moisture content is supplied from the downstream side, so that the moisture content is lowered. Therefore, when the moisture content of lignite is lowered, lignite becomes difficult to aggregate and hardly adheres. Thereby, since generation | occurrence | production of the deposit by adhesion | attachment of lignite can be suppressed and generation | occurrence | production of the aggregate by aggregation of lignite can be suppressed, lignite can be made to flow suitably.

  Moreover, according to the structure of Example 1, since the screw feeder 45 is provided in the inside of the fluidized bed 3, and the lignite can be supplied from the downstream side of the flow direction to the upstream side by the screw feeder 45, it is complicated. The fluidized bed drying apparatus 1 itself can be simplified without using the configuration.

  Further, according to the configuration of the first embodiment, by providing the screw feeder 45 on the lower side of the fluidized bed 3, lignite can be supplied from the downstream side of the drying chamber 12 to the upstream side on the lower side of the fluidized bed 3. it can. That is, the brown coal around the dry coal discharge port 41 can be supplied to the lower side of the fluidized bed 3 on the upstream side of the drying chamber 12. For this reason, since the fluidized-bed drying apparatus 1 can supply the lignite on the downstream side toward the lignite on the upstream side of the drying chamber 12 that easily deposits on the lower side of the fluidized bed 3, the occurrence of poor flow is preferable. Can be suppressed.

  Next, the fluidized bed drying apparatus 200 according to the second embodiment will be described with reference to FIG. FIG. 3 is a schematic configuration diagram schematically illustrating the fluidized bed drying apparatus according to the second embodiment. In the second embodiment, parts that are different from the first embodiment will be described in order to avoid duplicated descriptions, and parts that have the same configuration as the first embodiment are denoted by the same reference numerals. In the fluidized bed drying apparatus 1 according to the first embodiment, the screw feeder 45 is provided on the lower side in the vertical direction of the fluidized bed 3. However, in the fluidized bed drying apparatus 200 according to the second embodiment, the screw feeder 201 is connected to the fluidized bed 3. It is provided on the upper side in the vertical direction. Hereinafter, the fluidized bed drying apparatus 200 according to the second embodiment will be described.

  As shown in FIG. 3, in the fluidized bed drying apparatus 200 according to the second embodiment, the screw feeder 201 is configured in the same manner as in the first embodiment, and a part of the lignite on the downstream side in the flow direction is transferred to the upstream side in the flow direction. It functions as a backflow supply unit that flows back to the back. That is, the screw feeder 201 includes the motor 51, the rotating shaft 52, the screw portion 53, and the outer cylinder 54 as in the first embodiment. The screw feeder 201 is provided with the rotating shaft 52 horizontally along the flow direction and on the upper side of the fluidized bed 3 in the vertical direction. That is, the screw feeder 201 is provided away from the gas dispersion plate 6 in the vertical direction, and is provided close to the free board portion F.

  Therefore, when the rotating shaft 52 is rotated by the motor 51, the screw feeder 201 rotates part of the brown coal on the downstream side in the flow direction of the drying chamber 12 above the fluidized bed 3 by rotating the screw part 53. Is taken into the inside from the downstream end of the outer cylinder 54. The brown coal taken in the outer cylinder 54 flows from the downstream side in the flow direction of the backflow supply path 55 toward the upstream side as the screw portion 53 rotates. And the brown coal which distribute | circulated the backflow supply path 55 is discharged | emitted from the upstream edge part of the outer cylinder 54 outside, and is supplied to the drying chamber 12 in the flow direction upstream in the fluid bed 3 upper side. .

  As described above, according to the configuration of the second embodiment, by providing the screw feeder 201 on the upper side of the fluidized bed 3, lignite is supplied from the downstream side of the drying chamber 12 to the upstream side of the fluidized bed 3. can do. For this reason, since the fluidized bed drying apparatus 200 does not inhibit the flow of the lignite in the lower side of the fluidized bed by the screw feeder 201, a part of the lignite on the downstream side while appropriately flowing the lignite in the flow direction. Can be suitably supplied toward the upstream side.

  Next, with reference to FIG. 4, the fluidized bed drying apparatus 210 which concerns on Example 3 is demonstrated. FIG. 4 is a schematic configuration diagram schematically illustrating the fluidized bed drying apparatus according to the third embodiment. In the third embodiment, portions that are different from the first embodiment will be described in order to avoid duplicated descriptions, and the same reference numerals will be given to portions that have the same configuration as the first embodiment. In the fluidized bed drying apparatus 1 according to the first embodiment, the screw feeder 45 is provided on the lower side in the vertical direction of the fluidized bed 3. However, in the fluidized bed drying apparatus 210 according to the third embodiment, the screw feeder 211 is disposed in the flow direction. It is provided diagonally. Hereinafter, the fluidized bed drying apparatus 210 according to the third embodiment will be described.

  As shown in FIG. 4, in the fluidized bed drying apparatus 210 according to the third embodiment, the screw feeder 211 is configured in the same manner as in the first embodiment, and a part of the lignite on the downstream side in the flow direction is transferred to the upstream side in the flow direction. It functions as a backflow supply unit that flows back to the back. That is, the screw feeder 211 includes the motor 51, the rotating shaft 52, the screw portion 53, and the outer cylinder 54 as in the first embodiment. The screw feeder 211 is provided with the rotation shaft 52 extending in the flow direction and the rotation shaft 52 inclined with respect to the horizontal. That is, the rotating shaft 52 is provided with an upstream end in the flow direction on the upper side in the vertical direction of the fluidized bed and a downstream end in the flow direction on the lower side in the vertical direction of the fluidized bed. . For this reason, as for the screw feeder 211, the edge part of the upstream of a flow direction is located around the brown coal injection port 31, and the edge part of the downstream of a flow direction is located around the dry coal discharge port 41.

  Therefore, when the rotating shaft 52 is rotated by the motor 51, the screw feeder 211 rotates the screw part 53, so that a part of the brown coal on the downstream side in the flow direction of the drying chamber 12 on the lower side of the fluidized bed 3. Is taken into the inside from the downstream end of the outer cylinder 54. The brown coal taken in the outer cylinder 54 flows from the downstream side in the flow direction of the backflow supply path 55 toward the upstream side as the screw portion 53 rotates. And the brown coal which distribute | circulated the backflow supply path 55 is discharged | emitted from the upstream edge part of the outer cylinder 54 outside, and is supplied to the drying chamber 12 in the flow direction upstream in the fluid bed 3 upper side. .

  As described above, according to the configuration of Example 3, the upstream end of the screw feeder 211 is provided above the fluidized bed 3, and the downstream end of the screw feeder 211 is disposed below the fluidized bed 3. By providing, the lignite on the lower side of the fluidized bed 3 on the downstream side of the drying chamber 12 can be supplied to the upper side of the fluidized bed 3 on the upstream side of the drying chamber 12. That is, the lignite around the dry coal discharge port 41 can be supplied around the lignite input port 31. For this reason, since the fluidized bed drying apparatus 210 can supply the lignite having a lower moisture content near the dry coal discharge port 41 toward the lignite having a higher moisture content immediately after the lignite is charged, the fluidized bed drying apparatus 210 is upstream in the flow direction. The water content of lignite can be suitably reduced.

  Next, a fluidized bed drying apparatus 220 according to Example 4 will be described with reference to FIGS. 5 and 6. FIG. 5 is a schematic configuration diagram schematically illustrating the fluidized bed drying apparatus according to the fourth embodiment. FIG. 6 is a plan view schematically illustrating the fluidized bed drying apparatus according to the fourth embodiment. In the fourth embodiment, portions that are different from the first embodiment will be described in order to avoid duplicated descriptions, and the same reference numerals are given to the portions that have the same configuration as the first embodiment. In the fluidized bed drying apparatus 1 according to the first embodiment, one screw feeder 45 is provided in one drying chamber 12. However, in the fluidized bed drying apparatus 220 according to the fourth embodiment, the drying chamber 12 is fluidized by the partition plate 222. A plurality of screw feeders 221 are provided along the direction. Hereinafter, the fluidized bed drying apparatus 220 according to the fourth embodiment will be described.

  As shown in FIG. 5, the fluidized bed drying apparatus 220 according to the fourth embodiment includes a wind chamber 11 provided on the lower side and a drying chamber 12 provided on the upper side across the gas dispersion plate 6. 5 is provided. A plurality of partition plates 222 are provided inside the drying furnace 5. The some partition plate 222 has divided the drying chamber 12 into plurality along the flow direction of brown coal. In Example 4, two partition plates 222 are provided, and three drying chambers 12 are provided, that is, a drying chamber 12a on the upstream side in the flow direction, a drying chamber 12b on the midstream side in the flow direction, and a drying chamber on the downstream side in the flow direction. It is divided into chambers 12c.

  In the drying chamber 12 of the drying furnace 5, as in Example 1, a lignite charging port 31 for charging lignite, a drying coal discharge port 41 for discharging dry coal by heating and drying lignite, fluidized gas, and generated steam. And a plurality of screw feeders 221 are provided.

  The brown coal inlet 31 is formed on the upper side in the vertical direction of one end side (the left side in the figure) of the drying chamber 12a on the upstream side. A coal supply device 111 is connected to the lignite charging port 31, and the lignite supplied from the coal supply device 111 is supplied to the drying chamber 12a on the upstream side.

  The dry charcoal discharge port 41 is formed on the lower side in the vertical direction on the other end side (the right side in the figure) of the downstream drying chamber 12c. The brown coal dried in the drying chamber 12 is discharged as dry coal from the dry coal discharge port 41, and the discharged dry coal is supplied toward the cooler 131 described above.

  The gas discharge port 42 is formed on the upper side in the vertical direction on the other end side of the drying chamber 12c on the downstream side. The gas discharge port 42 discharges the generated steam generated from the drying chamber 12 together with the fluidized gas supplied to the drying chamber 12 when the lignite is dried. The fluidized gas and generated steam discharged from the gas discharge port 42 are supplied toward the dust collector 139 described above.

  Accordingly, the lignite supplied to the upstream drying chamber 12a via the lignite inlet 31 flows from the upstream drying chamber 12a to the downstream side by flowing with the fluidized gas supplied via the gas dispersion plate 6. The fluidized bed 3 is formed over the drying chamber 12 c, and the free board portion F is formed above the fluidized bed 3. The flow direction of the fluidized bed 3 formed in the drying chamber 12 is a direction from one end side to the other end side of the drying chamber 12. And the lignite supplied to the drying chamber 12a of the upstream side is dried while flowing along the flow direction, so that moisture contained in the lignite becomes generated steam, and from the gas discharge port 42 together with the fluidizing gas. Discharged. The lignite from which moisture has been removed and which has flowed to the other end of the drying chamber 12c on the downstream side is discharged from the dry coal discharge port 41 as dry coal.

  In Example 4, two screw feeders 221 are provided, and one screw feeder 221a is provided between the upstream drying chamber 12a and the downstream drying chamber 12c, and the other screw feeder 221b. Is provided between the drying chamber 12b on the middle stream side and the drying chamber 12c on the downstream side. As shown in FIG. 6, the two screw feeders 221a and 221b are provided in parallel with a predetermined interval in the width direction orthogonal to the flow direction.

  One screw feeder 221a is configured in the same manner as in the first embodiment, and supplies a part of the lignite in the downstream drying chamber 12c back to the upstream drying chamber 12a. That is, the screw feeder 221a includes the motor 51a, the rotating shaft 52a, the screw portion 53a, and the outer cylinder 54a, as in the first embodiment. The screw feeder 221a is provided with an outer cylinder 54a penetrating the two partition plates 222, a rotating shaft 52a provided horizontally along the flow direction, and provided below the fluidized bed 3 in the vertical direction. ing.

  The other screw feeder 221b is also configured in the same manner as in Example 1, and a part of the lignite in the downstream drying chamber 12c is fed back to the intermediate drying chamber 12b. That is, the screw feeder 221b has a motor 51b, a rotating shaft 52b, a screw portion 53b, and an outer cylinder 54b, as in the first embodiment. The screw feeder 221b is provided with an outer cylinder 54b penetrating through one partition plate 222, a rotating shaft 52b provided horizontally along the flow direction, and provided below the fluidized bed 3 in the vertical direction. ing.

  Accordingly, in the one screw feeder 221a, when the rotating shaft 52a is rotated by the motor 51a, the screw portion 53a rotates, so that a part of the lignite in the downstream drying chamber 12c is below the fluidized bed 3. Then, it is taken into the inside from the downstream end of the outer cylinder 54a. The brown coal taken in the outer cylinder 54a flows from the downstream side in the flow direction of the backflow supply path 55a toward the upstream side as the screw portion 53a rotates. And the lignite which distribute | circulated the backflow supply path | route 55a is discharged | emitted from the upstream edge part of the outer cylinder 54a outside, and is supplied to the drying chamber 12a of an upstream in the downward side of the fluidized bed 3. FIG.

  Further, when the rotating shaft 52b is rotated by the motor 51b, the other screw feeder 221b rotates the screw portion 53b, so that a part of the lignite in the downstream drying chamber 12c is formed on the lower side of the fluidized bed 3. Then, it is taken in from the downstream end of the outer cylinder 54b. The brown coal taken into the outer cylinder 54b circulates from the downstream side to the upstream side in the flow direction of the backflow supply path 55b as the screw portion 53b rotates. And the lignite which distribute | circulated the backflow supply path | route 55b is discharged | emitted from the upstream edge part of the outer cylinder 54b outside, and is supplied to the drying chamber 12b of the midstream side in the downward side of the fluidized bed 3. FIG.

  As mentioned above, according to the structure of Example 4, one screw feeder 221a can supply a part of brown coal in the downstream drying chamber 12c to the upstream drying chamber 12a. Further, the other screw feeder 221b can supply a part of the lignite in the downstream drying chamber 12c to the intermediate drying chamber 12b. For this reason, lignite in the downstream drying chamber 12c having a low water content is supplied to the upstream drying chamber 12a. Further, the lignite in the downstream drying chamber 12c having a low water content is supplied to the drying chamber 12b on the middle stream side. Thereby, even if lignite is supplied to the drying chamber 12a on the upstream side from the lignite charging port 31, lignite having a low moisture content is supplied from the drying chamber 12c on the downstream side, so that the moisture content is lowered. Moreover, since the brown coal with a low moisture content is supplied to the drying chamber 12b on the middle stream side from the drying chamber 12c on the downstream side, the moisture content is lowered. Therefore, when the moisture content of lignite is lowered, lignite becomes difficult to aggregate and hardly adheres. Thereby, since generation | occurrence | production of the deposit by adhesion | attachment of lignite can be suppressed and generation | occurrence | production of the aggregate by aggregation of lignite can be suppressed, lignite can be made to flow suitably.

  In Examples 1 to 4, lignite is supplied from the downstream side in the flow direction to the upstream side using the screw feeders 45, 201, 211, and 221. However, the present invention is not limited to this configuration. For example, a scraper chain conveyor may be applied instead of the screw feeders 45, 201, 211, and 221. In this case, the scraper chain conveyor is preferably provided in the drying chamber 12. Further, in Example 4, the drying chamber 12 is divided into a plurality along the flow direction by the partition plate 222, and a plurality of screw feeders 221 are provided, but even when the drying chamber 12 is not divided into a plurality, The same effect can be obtained by providing a plurality of screw feeders 221.

DESCRIPTION OF SYMBOLS 1 Fluidized bed drying apparatus 3 Fluidized bed 5 Drying furnace 6 Gas dispersion plate 11 Air chamber 12 Drying chamber 31 Brown coal inlet 41 Dry coal outlet 42 Gas outlet 45 Screw feeder 51 Motor 52 Rotating shaft 53 Screw part 54 Outer cylinder 55 Backflow Supply path 200 Fluidized bed drying apparatus (Example 2)
201 Screw feeder (Example 2)
210 Fluidized bed dryer (Example 3)
211 Screw feeder (Example 3)
220 Fluidized bed dryer (Example 4)
221 Screw feeder (Example 4)
222 Partition board F Free board part

Claims (8)

A drying furnace in which a fluidized bed is formed by the supplied wet fuel flowing along the flow direction by the fluidizing gas;
Provided in the drying furnace on the upstream side in the flow direction, and a fuel inlet for introducing the wet fuel into the drying furnace;
A fuel discharge port provided in the drying furnace on the downstream side in the flow direction, for discharging the wet fuel dried in the drying furnace;
A reverse flow supply unit provided inside the fluidized bed and configured to flow backward from the downstream side in the flow direction toward the upstream side to supply the wet fuel;
A partition plate that divides the inside of the drying furnace into a plurality of drying chambers along the flow direction;
The backflow supply unit is disposed through the partition plate, and supplies the wet fuel while backflowing from the drying chamber on the downstream side in the flow direction toward the drying chamber on the upstream side in the flow direction. A fluidized bed drying apparatus. The plurality of drying chambers are three drying chambers composed of a drying chamber on the upstream side in the flow direction, a drying chamber on the midstream side in the flow direction, and a drying chamber on the downstream side in the flow direction,
The backflow supply unit supplies the wet fuel while backflowing from the drying chamber on the downstream side in the flow direction to the drying chamber on the midstream side in the flow direction, and from the drying chamber on the downstream side in the flow direction. The fluidized bed drying apparatus according to claim 1 , wherein the wet fuel is supplied while flowing back toward the drying chamber on the upstream side in the flow direction. The backflow supply unit, a fluidized bed dryer according to claim 1 or 2, characterized in that it has a screw feeder for supplying the wet fuel toward the upstream side from the downstream side of the flow direction. The fluidized bed drying apparatus according to claim 3 , wherein the screw feeder is provided over the flow direction and is provided on a lower side in the vertical direction of the fluidized bed. The fluidized bed drying apparatus according to claim 3 , wherein the screw feeder is provided over the flow direction and is provided on an upper side in the vertical direction of the fluidized bed. The fuel inlet is provided on the upper side in the vertical direction of the drying furnace,
The fuel discharge port is provided on the lower side in the vertical direction of the drying furnace,
The screw feeder is provided with an upstream end in the flow direction on the upper side in the vertical direction of the fluidized bed and a downstream end in the flow direction on the lower side in the vertical direction of the fluidized bed. Thus, the fluidized bed drying apparatus according to claim 3 , wherein the fluidized bed drying apparatus is provided obliquely over the flow direction. A fluidized bed drying apparatus according to any one of claims 1 to 6 ,
A gasification furnace for treating the wet fuel after drying supplied from the fluidized bed drying device and converting it into gasification gas;
A gas turbine operated using the gasified gas as fuel;
A steam turbine operated by steam generated by an exhaust heat recovery boiler that introduces turbine exhaust gas from the gas turbine;
A gasification combined power generation facility comprising the gas turbine and a generator connected to the steam turbine. The wet fuel supplied to the drying oven at Rukoto to flow along the flow direction by the fluidizing gas, while forming a fluidized bed in the interior of the drying oven, a drying process of drying the wet fuel ,
The drying furnace is divided into a plurality of drying chambers along the flow direction by a partition plate,
By the partition plate backflow supply unit which is disposed through the inside of the fluidized bed, said part of the wet fuel in the drying chamber in the flow direction of the downstream side, the drying of the upstream side of the flow direction A drying method, characterized by being fed back to the chamber .

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