WO2012161130A1 - Fluidized bed drying device - Google Patents

Abstract

Provided are: a drying furnace (5) that forms a fluidized bed (3) internally by using a fluidized gas to force lignite to flow from an upstream side to a downstream side; a cyclone dust collector (34) which is disposed inside the drying furnace (5), and which is capable of collecting lignite contained in exhaust gas discharged from the drying furnace; and an ejector (35) which is disposed inside the drying furnace (5), and which feeds the lignite collected by the dust collector (34) toward the upstream side of the fluidized bed (3).

Description

Fluidized bed dryer

The present invention relates to a fluidized bed drying apparatus that dries while flowing wet fuel such as lignite.

Conventionally, as such a fluidized bed drying apparatus, a fluidized dryer having a drying chamber which is a dispersible plate having a plurality of openings at the bottom and an air chamber located at the lower portion of the drying chamber is known. (For example, refer to Patent Document 1). This fluid dryer dries while flowing the material to be dried by supplying fluidizing gas (drying gas) from the wind chamber to the drying chamber through the dispersion plate, and the fluidization gas supplied to the drying chamber The gas is discharged from an exhaust port formed in the upper part of the drying chamber together with the vapor generated from the material to be dried.

JP 2008-89243 A

In such a conventional fluidized bed drying apparatus, the gas discharged through the exhaust port contains dust-like material to be dried that has been dried in the drying chamber. For this reason, a dust collector is usually connected to the exhaust port of the fluidized bed drying apparatus. When a dust collector is provided outside the fluidized bed drying apparatus, it is necessary to separately add a configuration for handling the collected material to be dried, which is a complicated configuration.

For this reason, it is considered to provide a dust collector around the exhaust port in the drying chamber. In this case, since the matter to be dried accumulates in the dust collector, it is necessary to remove the accumulated matter to be dried. However, if the object to be removed is in an undried state, the object to be dried is mixed into the object to be dried after being discharged from the drying chamber, and the object to be discharged is undried. There is a possibility of becoming a state.

Therefore, an object of the present invention is to provide a fluidized bed drying apparatus capable of suitably drying wet fuel even when dust collecting means is provided in the drying furnace.

The fluidized bed drying apparatus of the present invention is provided with a drying furnace in which a fluidized bed is formed by flowing a wet fuel from the upstream side to the downstream side with a fluidizing gas, and a drying furnace provided in the drying furnace. Dust collecting means capable of collecting wet fuel contained in the exhaust gas discharged, and an ejector provided in the drying furnace and supplying the wet fuel collected by the dust collecting means toward the upstream side of the fluidized bed And.

According to this configuration, the wet fuel collected by the dust collecting means can be returned to the upstream side of the fluidized bed by the ejector. Thereby, since it can suppress that the wet fuel of an undried state is supplied to the downstream of a fluidized bed, the possibility that the wet fuel discharged | emitted from a downstream may be in an undried state can be reduced. Moreover, by returning the wet fuel in an undried state to the upstream side of the fluidized bed, drying of the wet fuel in the fluidized bed can be promoted. Therefore, even when the dust collecting means is provided in the drying furnace, the wet fuel can be suitably dried.

In this case, the dust collecting means includes a suction port for sucking exhaust gas, a cyclone dust collection unit for separating wet fuel from the suctioned exhaust gas, and a fuel discharge port for discharging wet fuel separated in the cyclone dust collection unit. The cyclone dust collecting section preferably has a gas discharge port for discharging the exhaust gas from which the wet fuel is separated, and the ejector is preferably connected to the fuel discharge port.

According to this configuration, the wet fuel in the exhaust gas separated in the cyclone dust collecting unit can be discharged from the fuel discharge port, and the wet fuel discharged from the fuel discharge port is returned to the fluidized bed by the ejector. Can do.

In this case, superheated steam is supplied to the ejector, and the ejector passes the fuel exhaust port through the supplied superheated steam so that the lignite discharged from the fuel exhaust port is upstream of the fluidized bed together with the superheated steam. It is preferable to supply toward the side.

According to this configuration, the ejector can supply the wet fuel collected by the dust collecting means to the upstream side of the fluidized bed using the superheated steam, and therefore can promote the drying of the wet fuel. Also, drying in the fluidized bed can be promoted.

According to the fluidized bed drying apparatus of the present invention, even if the dust collecting means is provided in the drying furnace, the wet fuel collected by the dust is provided upstream of the fluidized bed by providing the ejector in the drying furnace. Since it can return, discharge | emission of the wet fuel of an undried state can be suppressed and a wet fuel can be dried suitably.

FIG. 1 is a schematic configuration diagram of a combined coal gasification combined power generation facility to which a fluidized bed drying apparatus according to the present embodiment is applied. FIG. 2 is a schematic configuration diagram schematically illustrating the fluidized bed drying apparatus according to the present embodiment.

Hereinafter, a fluidized bed drying apparatus 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 combined coal gasification combined power generation facility to which a fluidized bed drying apparatus according to the present embodiment is applied. The coal gasification combined power generation facility (IGCC: Integrated Coal Gasification Combined Cycle) 100 to which the fluidized bed drying apparatus 1 of the present embodiment is applied adopts an air combustion method that generates coal gas in a gasification furnace using air as an oxidizing agent. The coal gas refined by the gas purifier is supplied as fuel gas to the gas turbine equipment for power generation. 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 fluidized bed drying device 1, a pulverized coal machine (mill) 113, a coal gasification furnace 114, and a char recovery device 115. , A gas purifier 116, 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 fluidized bed drying apparatus 1 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 1 is provided with a cooler 131 that cools dried lignite (dry coal) taken out from the lower portion, and the dried and cooled dried coal is stored in the dried coal bunker 132. In addition, the fluidized bed drying apparatus 1 is provided with a dry coal electrostatic precipitator 134 that separates dry coal particles from steam taken out from above, and the dry coal particles separated from the steam are stored in the dry coal bunker 132. . The steam from which the dry coal is separated by the dry coal electrostatic precipitator 134 is compressed by the steam compressor 135 and then supplied to the fluidized bed drying apparatus 1 as drying steam.

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 gasification furnace 114 is supplied with the pulverized coal processed by the pulverized coal machine 113 and the 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, 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. 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 collection device 115 includes a dust collecting device 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 facility 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.

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

Here, the operation of the coal gasification combined cycle facility 100 of the present embodiment will be described.

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 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 device 1 is separated into dry coal particles by the dry coal electrostatic precipitator 134 and compressed by the steam compressor 135 and then returned to the fluidized bed drying device 1 as drying steam. It is. 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 subjected to gas purification by removing impurities such as sulfur compounds and nitrogen compounds in 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 discharged 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 present embodiment. The fluidized bed drying apparatus 1 of the present embodiment heats and drys lignite, which is coal having a high water content, with fluidizing 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 chamber chamber 11 located on the lower side in the vertical direction (lower side in the drawing) and a drying chamber 12 located on the upper side in the vertical direction (upper side in the drawing). Yes. A number of through holes are formed in the gas dispersion plate 6, and a fluidizing gas such as steam is introduced into the chamber chamber 11.

The drying chamber 12 of the drying furnace 5 includes a brown coal charging port 31 for charging lignite, a dry coal discharging port 41 for discharging the heat-dried lignite as dry coal, a heat transfer tube 33 for heating the lignite, and an exhaust gas. A dust collector 34 for separating the lignite and the ejector 35 for returning the separated lignite to the fluidized bed 3 are provided.

The brown coal inlet 31 is formed on one end side (the left side in the drawing) of the drying chamber 12. The crusher 123 described above is connected to the lignite charging port 31, and the pulverized lignite is supplied to the drying chamber 12.

The dry coal discharge port 41 is formed at the bottom of 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 lignite supplied to the drying chamber 12 flows by the fluidized gas supplied via the gas dispersion plate 6, thereby forming the fluidized bed 3 in the drying chamber 12. A free board portion F is formed above the formed fluidized bed 3. The flow direction of the fluidized bed 3 formed in the drying chamber 12 is the longitudinal direction of the drying chamber 12 (the left-right direction in FIG. 2). The fluidized gas supplied to the drying chamber 12 goes to the dust collector 34 together with the steam generated by drying the lignite.

The heat transfer tube 33 is provided inside the fluidized bed 3. The heat transfer pipe 33 is supplied with drying steam therein to remove moisture in the brown coal of the fluidized bed 3. Therefore, when the drying steam is supplied to the heat transfer pipe 33, the heat transfer pipe 33 uses the latent heat of the drying steam to dry the lignite in the drying chamber 12. Thereafter, the drying steam used for drying is discharged to the outside of the drying chamber 12.

The dust collector 34 is a cyclone type dust collector, and includes a suction port 45, a cyclone dust collector 46 connected to the suction port 45, and a fuel discharge port 47 connected to the lower side of the cyclone dust collector 46. And a gas discharge port 48 connected to the upper side of the cyclone dust collecting portion 46.

The cyclone dust collecting portion 46 is formed in a tapered shape that tapers from the upper side to the lower side in the vertical direction. The axial direction of the cyclone dust collection part 46 comprised in this way is a perpendicular direction. In this cyclone dust collection part 46, the brown coal contained in the exhaust gas which flowed into the inside is isolate | separated. That is, the inflowing exhaust gas becomes a cyclone flow inside the cyclone dust collecting unit 46, and the lignite in the exhaust gas is guided to the fuel discharge port 47 on the lower side, while the exhaust gas from which the lignite has been separated is To the gas discharge port 48 on the side.

The suction port 45 is provided so as to extend in the tangential direction on the upper outer periphery of the cyclone dust collecting portion 46. The suction port 45 has one end connected to the cyclone dust collecting portion 46 and the other end serving as a suction port 51 for sucking exhaust gas. The suction port 45 supplies the exhaust gas sucked from the suction port 51 toward the cyclone dust collecting unit 46.

The fuel discharge port 47 is provided extending in the axial direction on the lower side of the cyclone dust collecting portion 46. The upper end portion of the fuel discharge port 47 is connected to the cyclone dust collecting portion 46, and the lower end portion thereof serves as a fuel discharge port 52 for discharging brown coal. The fuel discharge port 52 is connected to the ejector 35. The fuel discharge port 47 discharges the lignite separated in the cyclone dust collecting section 46 toward the ejector 35.

The gas discharge port 48 is provided extending in the axial direction on the upper side of the cyclone dust collecting portion 46. The gas discharge port 48 has an upper end connected to the dry coal electrostatic precipitator 134 located outside the drying furnace 5, and a lower end connected to the gas discharge port 53 for discharging the exhaust gas after the lignite separation. It has become. At this time, the lower end portion of the gas discharge port 48 is provided so as to be located inside the cyclone dust collecting portion 46. The gas discharge port 48 discharges the exhaust gas from which the lignite has been separated in the cyclone dust collecting section 46 toward the dry coal electric dust collector 134 from the gas discharge port 53.

The ejector 35 is formed in a tubular shape having a steam flow path R1 in which superheated steam flows, and the fuel discharge port 52 is connected to the middle of the steam flow path R1. One end (right side in the figure) of the ejector 35 is located outside the drying furnace 5, and superheated steam flows from one end thereof. On the other hand, the ejector 35 has the other end (the left side in the drawing) positioned above the upstream side of the fluidized bed 3 formed inside the drying furnace 5, and lignite with superheated steam from the other end. Discharged.

That is, when superheated steam flows from one end of the ejector 35, the superheated steam flows along the steam flow path R1. When the superheated steam flowing along the steam flow path R1 passes through the fuel discharge port 52, the lignite discharged from the fuel discharge port 52 is drawn into the steam flow path R1. The superheated steam that has passed through the fuel discharge port 52 flows out from the other end of the ejector 35 together with the brown coal drawn from the fuel discharge port 52.

In the fluidized bed drying apparatus 1 configured as described above, when lignite is supplied to the drying chamber 12 from the lignite inlet 31, the supplied lignite is fluidized by the fluidized gas supplied via the gas dispersion plate 6. As a result, the fluidized bed 3 is formed. The lignite that has become the fluidized bed 3 is dried by being heated by the fluidizing gas and the heat transfer tube 33. Thereafter, the fluidized gas becomes exhaust gas together with the generated steam generated from the lignite and goes to the dust collector 34. Exhaust gas directed to the dust collector 34 is sucked from the suction port 51 of the dust collector 34 and supplied to the cyclone dust collector 36 through the suction port 45.

When the exhaust gas is supplied to the cyclone dust collecting unit 36, the cyclone dust collecting unit 36 separates the lignite contained in the exhaust gas. The separated lignite is directed to the fuel discharge port 47, while the exhaust gas after the lignite separation is directed to the gas discharge port 48 and then supplied to the dry coal electric dust collector 134. The lignite toward the fuel discharge port 47 is drawn into the ejector 35 and discharged to the upstream side of the fluidized bed 3 formed in the drying chamber 12 together with the superheated steam supplied to the ejector 35. Then, the lignite dried in the drying chamber 12 is discharged from the dry coal discharge port 41.

As described above, according to the configuration of the present embodiment, the lignite collected in the dust collector 34 by the ejector 35 can be returned to the upstream side of the fluidized bed 3. Thereby, since undried lignite is not supplied to the downstream of the fluidized bed 3, it can suppress that undried lignite is discharged | emitted from the dry coal discharge port 41. FIG. In addition, since the undried lignite can be returned to the upstream side of the fluidized bed 3, the drying of the lignite in the fluidized bed 3 can be promoted.

Moreover, according to the structure of a present Example, while separating the lignite contained in exhaust gas with the cyclone type dust collector 34, the exhaust gas from which the lignite was isolate | separated can be discharged | emitted from the drying furnace 5. Thus, the lignite after separation can be discharged from the fuel discharge port. Thereby, the lignite discharged from the fuel discharge port 52 can be discharged toward the fluidized bed 3 by the ejector 35.

Further, according to the configuration of the present embodiment, the lignite discharged from the fuel discharge port 52 can be drawn into the steam flow path R1 of the ejector 35 by the inflowing superheated steam. For this reason, the ejector 35 can dry the lignite which circulates with superheated steam suitably.

In this embodiment, the other end of the ejector 35 is positioned on the upper side upstream of the fluidized bed 3. However, the present invention is not limited to this configuration, and the other end of the ejector 35 is connected to the fluidized bed 3. It may be located inside the upstream side.

In the present embodiment, the dust collector 34 is applied to the cyclone dust collector 34. However, the present invention is not limited to this configuration. For example, the dust collector 34 may be applied to a filter dust collector.

DESCRIPTION OF SYMBOLS 1 Fluidized bed drying apparatus 3 Fluidized bed 5 Drying furnace 6 Gas dispersion plate 11 Chamber room 12 Drying room 31 Brown coal input port 33 Heat transfer pipe 34 Dust collector 35 Ejector 41 Dry coal discharge port 45 Suction port 46 Cyclone dust collection part 47 Fuel discharge Port 48 Gas exhaust port 51 Suction port 52 Fuel exhaust port 53 Gas exhaust port R1 Steam flow path

Claims (3)

A drying furnace that forms a fluidized bed inside by flowing the wet fuel from the upstream side toward the downstream side with the fluidizing gas;
A dust collecting means provided in the drying furnace and capable of collecting the wet fuel contained in exhaust gas discharged from the drying furnace;
An fluidized bed drying apparatus comprising: an ejector provided in the drying furnace and configured to supply the wet fuel collected by the dust collecting means toward the upstream side of the fluidized bed. The dust collecting means includes
A suction port for sucking the exhaust gas;
A cyclone dust collecting unit for separating the wet fuel from the exhaust gas sucked;
A fuel discharge port for discharging the wet fuel separated in the cyclone dust collecting unit;
A gas discharge port for discharging the exhaust gas from which the wet fuel is separated in the cyclone dust collecting unit;
The fluidized bed drying apparatus according to claim 1, wherein the ejector is connected to the fuel discharge port. The ejector is supplied with superheated steam,
The ejector supplies the lignite discharged from the fuel discharge port to the upstream side of the fluidized bed together with the superheated steam when the supplied superheated steam passes through the fuel discharge port. The fluidized bed drying apparatus according to claim 2.

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