JP2014145577A - Drying system of wet fuel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drying system of wet fuel in which fine powder can be properly removed from an exhaust gas exhausted from a device and can be reused as a fluidizing gas, and also the device can be simplified.SOLUTION: A drying system includes: a fluidized bed dryer 12 for fluidizing and drying coal by supplying a fluidizing gas; a cyclone 33 for separating particles (fine powder) of the coal with respect to the exhaust gas exhausted from the fluidized bed dryer 12; a cooling water atomiser 201 for making the separated particles fall by atomizing cooling water in the cyclone 33; a fluidizing gas feeder 202 for feeding the exhaust gas in which the particles are removed by the cyclone 33 to the fluidized bed dryer 12 as the fluidizing gas; and a heater 203 for heating the fluidizing gas that is fed to the fluidized bed dryer 12 by the fluidizing gas feeder 202.

Description

  The present invention relates to a wet fuel drying system in which wet fuel is dried by a fluidized gas in a fluidized bed.

  For example, a combined coal gasification power generation facility is a power generation facility that aims to further increase the efficiency and environmental performance compared to conventional coal-fired power generation by gasifying coal and combining it with combined cycle power generation. This coal gasification combined cycle power generation facility has a great merit that it can use coal with abundant resources, and it is known that the merit can be further increased by expanding the applicable coal types.

  Conventional coal gasification combined power generation facilities generally have a coal supply device, a drying device, a coal gasification furnace, a gas purification device, a gas turbine facility, a steam turbine facility, an exhaust heat recovery boiler, a gas purification device, and the like. ing. Therefore, after the coal is dried, it is pulverized, supplied to the coal gasifier as pulverized coal, and air is taken in. Gas) is produced. Then, the product gas is purified and then supplied to the gas turbine equipment to burn and generate high-temperature and high-pressure combustion gas to drive the turbine. The exhaust gas after driving the turbine recovers thermal energy by the exhaust heat recovery boiler, generates steam and supplies it to the steam turbine equipment, and drives the turbine. As a result, power generation is performed. On the other hand, the exhaust gas from which the thermal energy has been recovered is released into the atmosphere through a chimney after harmful substances are removed by the gas purification device.

  As a coal drying apparatus used for such a coal gasification combined power generation facility, there are those described in the following patent documents. In the multi-chamber fluidized bed classifying apparatus described in Patent Document 1, a fluidized bed is provided on the upper side of the wind box via a perforated plate type gas dispersion plate, and this chamber is partitioned into a drying chamber and a classification chamber by a partition plate, A communication passage is formed below the partition plate, and fluidized gas having a role as hot air for drying and a role as classification gas can be supplied to the wind box.

JP 2000-197854 A JP 2011-080746 A

  By the way, since a drying apparatus dries coal with fluidized gas, the exhaust gas which the fine powder mixed in fluidized gas is discharged | emitted. Therefore, in the conventional multi-chamber fluidized bed classifier described in Patent Document 1 described above, exhaust gas containing fine powder discharged from the gas discharge port is introduced into a solid-gas separation device such as a cyclone or a bag filter, and the fine powder is removed. It collects and separates. In order to recycle the exhaust gas from which fine powder has been removed and use it as a fluidizing gas, it is necessary to condense the evaporated water that has been mixed in, and a device such as a condenser must be provided in addition to a device such as a cyclone. This leads to an increase in the size and cost of the apparatus.

  The present invention solves the above-described problems, and removes fine particles from the exhaust gas discharged from the apparatus so that it can be reused as a fluidized gas. The purpose is to provide a system.

  In order to achieve the above object, a wet fuel drying system of the present invention includes a fluidized bed drying device that fluidizes and dries wet fuel by supplying a fluidizing gas, and is discharged from the fluidized bed drying device. A cyclone for separating fine particles from exhaust gas, a cooling water spraying device for lowering the fine particles separated by spraying cooling water in the cyclone, and the exhaust gas from which fine particles have been removed by the cyclone as fluidized gas A fluidized gas supply device that supplies the fluidized bed drying device and a heating device that heats the fluidized gas supplied to the fluidized bed drying device by the fluidized gas supply device.

  Therefore, in the fluidized bed drying device, the wet fuel is fluidized by the supplied fluidized gas and dried, and the exhaust gas discharged from the fluidized bed drying device is separated into fine particles by the cyclone, and the cooling water spray device is placed in the cyclone. While the fine particles are lowered by spraying the cooling water, the exhaust gas from which the fine particles have been removed by the cyclone is heated by the heating device and then supplied to the fluidized bed drying device by the fluidizing gas supply device as the fluidized gas. It will be. Therefore, fine particles can be appropriately removed from the exhaust gas and reused as fluidized gas, and the apparatus can be simplified.

  In the wet fuel drying system of the present invention, the storage tank storing the mixed liquid containing the cooling water sprayed by the cooling water spraying apparatus and the descending fine particles, and the liquid from which the waste is removed from the mixed liquid of the storage tank A cooling water circulation device for supplying the cooling water spraying device as cooling water is provided.

  Therefore, the liquid mixture of cooling water and fine particles is stored in the storage tank, and the liquid from which the waste is removed from the liquid mixture in the storage tank by the cooling water circulation device is supplied as cooling water to the cooling water spray device. The cooling water and the water condensed from the fluidized gas can be used effectively, and the processing cost can be reduced.

  In the wet fuel drying system of the present invention, the cooling water circulation device is provided with a cooling device for cooling the cooling water supplied to the cooling water spray device.

  Therefore, when the liquid from which the waste has been removed by the cooling water circulation device is supplied as cooling water to the cooling water spray device, the liquid is cooled by the cooling device. As a result, the exhaust gas is sprayed into the cyclone, and by efficiently cooling the exhaust gas, dust removal, cooling, and condensation can be performed efficiently.

  In the wet fuel drying system of the present invention, the storage tank has a separation function of separating the waste that has floated from the mixed liquid.

  Therefore, it is possible to easily separate the waste by rising and separating the waste from the liquid mixture, and it is possible to simplify the apparatus and reduce the cost.

  In the wet fuel drying system of the present invention, the cyclone is provided with a discharge pipe for discharging the exhaust gas from which fine particles have been removed from below, and the discharge port of the discharge pipe is disposed at the top and in the horizontal central side. On the other hand, the spray nozzle of the cooling water spray device is arranged at the upper part and on the outer peripheral side in the horizontal direction.

  Accordingly, the exhaust gas from which the fine particles have been removed by the discharge pipe is discharged from the lower part, the overall height of the cyclone can be reduced, and the compactness can be achieved, and the discharge port of the discharge pipe and the spray nozzle are provided. As a result, the cooling water is displaced in the horizontal direction, and cooling water can be prevented from being mixed into the discharge pipe.

  In the wet fuel drying system of the present invention, there is provided a heat exchange device for exchanging heat between the exhaust gas supplied to the cyclone and the fluidized gas supplied to the fluidized bed drying device by the fluidized gas supply device. It is characterized by that.

  Accordingly, the fluidized gas can be heated by the heat of the exhaust gas, and the exhaust heat efficiency can be improved.

  The wet fuel drying system of the present invention is characterized in that an inert gas or low-temperature air is applied as the fluidizing gas.

  Therefore, when the fluidizing gas is an inert gas or low-temperature air, the fine particles can be appropriately removed from the exhaust gas and reused as the fluidizing gas.

  According to the wet fuel drying system of the present invention, the cyclone that separates the fine particles from the exhaust gas discharged from the fluidized bed drying device, the cooling water spray device that sprays the cooling water into the cyclone, and the fine particles are removed. A fluidized gas supply device that supplies exhaust gas as fluidized gas to the fluidized bed drying device and a heating device that heats the fluidized gas are provided, so that fine particles can be appropriately removed from the exhaust gas and reused as fluidized gas. And the apparatus can be simplified.

FIG. 1 is a schematic configuration diagram illustrating a wet fuel drying system according to an embodiment of the present invention. FIG. 2 is a schematic configuration diagram of a coal gasification combined power generation facility to which the fluidized bed drying apparatus of the present embodiment is applied. FIG. 3 is a schematic side view showing the fluidized bed drying apparatus of the present embodiment. FIG. 4 is a schematic rear view showing the fluidized bed drying apparatus of the present embodiment. FIG. 5 is a schematic side view showing a modification of the fluidized bed drying apparatus.

  Exemplary embodiments of a wet fuel drying system according to the present invention will be described below in detail with reference to the accompanying drawings. In addition, this invention is not limited by this Example, Moreover, when there exists multiple Example, what comprises combining each Example is also included.

  FIG. 1 is a schematic configuration diagram illustrating a wet fuel drying system according to an embodiment of the present invention. FIG. 2 is a schematic configuration diagram of a coal gasification combined power generation facility to which a fluidized bed drying apparatus according to the present embodiment is applied. FIG. 3 is a schematic side view showing the fluidized bed drying apparatus of the present embodiment, and FIG. 4 is a schematic rear view showing the fluidized bed drying apparatus of the present embodiment.

  The coal gasification combined power generation facility (IGCC: Integrated Coal Gasification Combined Cycle) of the present embodiment adopts an air combustion method in which coal gas is generated in a gasification furnace using air as an oxidizer and is purified by a gas purification device. Coal gas is supplied as fuel gas to a gas turbine facility for power generation. That is, the combined coal gasification combined power generation facility of this embodiment is a power generation facility of an air combustion system (air blowing).

  In this embodiment, as shown in FIG. 2, the coal gasification combined power generation facility 10 includes a coal supply device 11, a fluidized bed drying device 12, a pulverized coal machine (mill) 13, a coal gasification furnace 14, and a char recovery device 15. , A gas refining device 16, a gas turbine facility 17, a steam turbine facility 18, a generator 19, and a heat recovery steam generator (HRSG) 20.

  The coal feeder 11 includes a raw coal bunker 21, a coal feeder 22, and a crusher 23. The raw coal bunker 21 can store coal and can drop a predetermined amount of coal into the coal feeder 22. The coal feeder 22 can transport the coal dropped from the raw coal bunker 21 by a conveyor or the like and drop it on the crusher 23. The crusher 23 can crush the dropped coal into a predetermined size.

  The fluidized bed drying device 12 supplies the fluidized gas to the coal introduced by the coal supply device 11 so as to heat and dry the coal while flowing, and can remove moisture contained in the coal. it can. The fluidized bed drying device 12 is provided with a cooler 31 that cools the extracted dry coal, and the dry coal is stored in the dry coal bunker 32. In addition, the fluidized bed drying apparatus 12 is provided with a cyclone 33 for separating dry coal particles from the extracted exhaust gas, and the dry coal particles separated from the exhaust gas are stored in the dry coal bunker 32 to separate the dry coal. The exhaust gas is returned to the fluidized bed drying device 12 as fluidized gas.

  The pulverized coal machine 13 is a coal pulverizer, and pulverizes coal (dried coal) dried by the fluidized bed dryer 12 into fine particles to produce pulverized coal. That is, in the pulverized coal machine 13, the dry coal stored in the dry coal bunker 32 is dropped by the coal feeder 36, and the dry coal is converted into pulverized coal having a predetermined particle size or less. The pulverized coal after being pulverized by the pulverized coal machine 13 is separated from the transfer gas by the bag filters 37a and 37b and stored in the supply hoppers 38a and 38b.

  The coal gasification furnace 14 can supply pulverized coal processed by the pulverized coal machine 13 and can be recycled by returning the char (unburned coal) recovered by the char recovery device 15. .

  That is, the coal gasification furnace 14 is connected to the compressed air supply line 41 from the gas turbine equipment 17 (compressor 61), and can supply compressed air compressed by the gas turbine equipment 17. The air separation device 42 separates and generates nitrogen and oxygen from air in the atmosphere, and a first nitrogen supply line 43 is connected to the coal gasification furnace 14, and a supply hopper 38 a, Charging lines 44a and 44b from 38b are connected. The second nitrogen supply line 45 is also connected to the coal gasification furnace 14, and the char return line 46 from the char recovery device 15 is connected to the second nitrogen supply line 45. Further, the oxygen supply line 47 is connected to the compressed air supply line 41. 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 14 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 14 is provided with a foreign matter removing device 48 that removes foreign matter mixed with pulverized coal. In this case, the coal gasification furnace 14 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 14 is provided with a gas generation line 49 for combustible gas toward the char recovery device 15, and can discharge combustible gas containing char. In this case, by providing a gas cooler in the gas generation line 49, the combustible gas may be cooled to a predetermined temperature and then supplied to the char recovery device 15.

  The char recovery device 15 includes a dust collector 51 and a supply hopper 52. In this case, the dust collector 51 is constituted by one or a plurality of bag filters or cyclones, and can separate char contained in the combustible gas generated in the coal gasification furnace 14. The combustible gas from which the char has been separated is sent to the gas purification device 16 through the gas discharge line 53. The supply hopper 52 stores the char separated from the combustible gas by the dust collector 51. A char return line 46 from the supply hopper 52 is connected to the second nitrogen supply line 45.

The gas purification device 16 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 15. The gas purifier 16 purifies the combustible gas to produce fuel gas and supplies it to the gas turbine equipment 17. In the gas purifier 16, 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 17 includes a compressor 61, a combustor 62, and a turbine 63, and the compressor 61 and the turbine 63 are connected by a rotating shaft 64. The combustor 62 has a compressed air supply line 65 connected to the compressor 61, a fuel gas supply line 66 connected to the gas purifier 16, and a combustion gas supply line 67 connected to the turbine 63. Further, the gas turbine equipment 17 is provided with a compressed air supply line 41 extending from the compressor 61 to the coal gasification furnace 14, and a booster 68 is provided in the middle. Therefore, in the combustor 62, the compressed air supplied from the compressor 61 and the fuel gas supplied from the gas purifier 16 are mixed and burned, and the rotating shaft 64 is rotated by the generated combustion gas in the turbine 63. By doing so, the generator 19 can be driven.

  The steam turbine facility 18 includes a turbine 69 that is coupled to the rotating shaft 64 in the gas turbine facility 17, and the generator 19 is coupled to the base end portion of the rotating shaft 64. The exhaust heat recovery boiler 20 is provided in the exhaust gas line 70 from the gas turbine equipment 17 (the turbine 63), and generates steam by exchanging heat between the air and the high temperature exhaust gas. Therefore, the exhaust heat recovery boiler 20 is provided with the steam supply line 71 between the steam turbine equipment 18 and the turbine 69 of the steam turbine equipment 18, the steam recovery line 72 is provided, and the steam recovery line 72 is provided with the condenser 73. Yes. A gas purification device 74 and a chimney 75 are connected to the exhaust heat recovery boiler 20.

  In the combined coal gasification combined cycle power generation facility 10 of this embodiment configured as described above, the raw coal is dropped into the crusher 23 by the coal feeder 22 and crushed by the coal feeder 11 and heated by the fluidized bed dryer 12. After being dried, it is cooled by a cooler 31 and stored in a dry charcoal bunker 32. The dry coal of the dry coal bunker 32 is pulverized by the pulverized coal machine 13 to produce pulverized coal, and is stored in the pulverized coal supply hoppers 38a and 38b. The pulverized coal stored in the pulverized coal supply hoppers 38a and 38b is supplied to the coal gasification furnace 14, and combusted with compressed air to be gasified, thereby combustible gas (coal gas containing carbon dioxide as a main component). ) Is generated. The combustible gas is separated into char by the char recovery device 15 and sent to the gas purification device 16.

  In the gas purification device 16, the combustible gas is purified by removing impurities such as sulfur compounds and nitrogen compounds to produce fuel gas. In the gas turbine facility 17, when the compressor 61 generates compressed air and supplies the compressed air to the combustor 62, the combustor 62 generates combustion gas by mixing the compressed air and the fuel gas and combusting, The turbine 63 is driven to generate power by the generator 19. The exhaust gas discharged from the gas turbine equipment 17 generates steam in the exhaust heat recovery boiler 20 and supplies the steam to the steam turbine equipment 18. In the steam turbine facility 18, the turbine 69 is driven by this steam and the generator 19 generates power. Thereafter, in the gas purification device 74, harmful substances in the exhaust gas discharged from the exhaust heat recovery boiler 20 are removed, and the purified exhaust gas is discharged from the chimney 75 to the atmosphere.

  Here, the wet fuel drying system of this embodiment will be described in detail.

  As shown in FIG. 1, the wet fuel drying system of this embodiment includes a fluidized bed drying device 12, a cyclone 33, a cooling water spray device 201, a fluidized gas supply device 202, and a heating device 203. doing. The fluidized bed drying apparatus 12 fluidizes and dries coal (wet fuel) by supplying fluidized gas. In this embodiment, an inert gas (for example, nitrogen gas) or low-temperature air is applied as the fluidizing gas.

  The fluidized bed drying apparatus 12 is a plug flow type drying apparatus, and as shown in FIGS. 3 and 4, a drying container 101, a coal input port 102, a dry coal discharge port 103, and a fluidized gas supply unit. 104 (104a, 104b, 104c), a gas discharge port 105, and heat transfer tubes 106, 107, 108 are provided.

  The drying container 101 has a hollow box shape, and has a coal inlet 102 for charging coal on one end side, and a dry coal discharge for discharging dry coal obtained by heating and drying coal at the lower part on the other end side. An outlet 103 is formed. In this case, although the coal input port 102 and the dry coal discharge port 103 are provided one by one at the end of the drying container 101, a plurality of them may be provided. Moreover, the drying container 101 can adjust the amount of coal supplied from the coal inlet 102 to the inside by a coal feeder 22 (see FIG. 2). Further, the drying container 101 can adjust the coal discharge amount by adjusting the rotational speed of a rotary valve (not shown) provided at the dry coal discharge port 103.

  Further, the drying container 101 is provided with a dispersion plate 109 having a plurality of through holes at a predetermined distance from the bottom plate 101a in the lower portion, so that the upper drying chamber (111, 112, 113) and the lower wind box 110 are provided. It is divided into. The drying container 101 is provided with a fluidizing gas supply unit 104 (104a, 104b, 104c) for supplying fluidizing gas to the bottom plate 101a via the wind box 110 and above the dispersion plate 109. Further, in the drying container 101, a gas discharge port 105 for discharging fluidized gas and generated steam is formed in the ceiling plate 101b on the dry coal discharge port 103 side.

  The drying container 101 is supplied with coal from the coal inlet 102 and supplied with fluidizing gas from the fluidizing gas supply unit 104 through the wind box 110 and the dispersion plate 109, so that the upper side of the dispersion plate 109. A fluidized bed S having a predetermined thickness is formed, and a free board portion F is formed above the fluidized bed S.

  The drying container 101 includes a first drying chamber 111 provided on the upstream side in the direction of coal flow, a second drying chamber 112 provided on the downstream side of the first drying chamber 111, and a flow of coal. A third drying chamber 113 provided on the most downstream side in the direction is provided.

  More specifically, the drying container 101 includes a plurality (two in this embodiment) of fluidized beds S in the direction of coal flow (three in this embodiment) by a plurality of (two in this embodiment) partition plates (partition members) 114 and 115. The partition plates 114 and 115 form coal passage openings 116 and 117. The partition plates 114 and 115 are arranged along a vertical direction orthogonal to the flow direction of coal, and are arranged at predetermined intervals in the flow direction of coal. Installed on. And each partition plate 114,115 is located so that a lower end part may be located in the dispersion plate 109 with a predetermined clearance, and an upper end part may be extended upwards from the fluidized bed S. FIG. That is, passage openings 116 and 117 having a predetermined height and width (opening area) are secured between the partition plates 114 and 115 and the dispersion plate 109, and the passage openings 116 and 117 are substantially The same opening area is set.

  As described above, the drying container 101 is divided into the first drying chamber 111, the second drying chamber 112, and the third drying chamber 113 by providing the partition plates 114 and 115. The drying chambers 111, 112, and 113 are In addition, communication is made above the partition plates 114 and 115. In this case, the first drying chamber 111 is a region (preheating drying region) where the freeboard portion F1 and the fluidized bed S1 are formed and the initial drying of the coal is performed. In the second drying chamber 112, the free board portion F2 and the fluidized bed S2 are formed, and the second drying chamber 112 is an area (fixed rate drying area) for performing the intermediate drying of coal. In the third drying chamber 113, the freeboard portion F3 and the fluidized bed S3 are formed, and the third drying chamber 113 is a region where the coal is later dried (decrease rate drying region).

  In this case, each of the drying chambers 111, 112, and 113 is set so that the floor area is substantially the same, but may be set to an optimum ratio according to the moisture content of the coal. It is desirable to set the floor area of the drying chamber 112 to the maximum. That is, the first drying chamber 111 is a preheat drying region in which the drying rate of coal is increased to a predetermined moisture content because the moisture content of the input coal is high. Since the drying rate of coal rises to a predetermined drying rate and becomes constant, the second drying chamber 112 is a constant rate drying region in which the drying rate of coal is constant. Since the drying rate of coal is processed when the moisture content of coal reaches a predetermined moisture content (limit moisture content), the third drying chamber 113 is a reduced rate drying region in which the drying rate of coal decreases. Therefore, the drying efficiency is improved by maximizing the volume of the second drying chamber 112 that is the constant rate drying region.

  In addition, the drying container 101 corresponds to the three drying chambers 111, 112, and 113, and the wind box 110 is made to flow of coal by a plurality of (two in this embodiment) partition plates (partition members) 118 and 119. It is divided into a plurality (three in this embodiment) in the direction. That is, the wind box 110 is divided into three wind boxes 110a, 110b, and 110c by two partition plates 118 and 119, and three flow boxes are provided so as to correspond to the three wind boxes 110a, 110b, and 110c. The activated gas supply units 104a, 104b, and 104c are provided. The fluidized bed drying apparatus 12 is provided with a gas supply line 121 for supplying a fluidized gas to each of the drying chambers 111, 112, and 113, and three branch lines 121 a and 121 b branched from the gas supply line 121. , 121c are connected to wind boxes 110a, 110b, 110c (fluidized gas supply units 104a, 104b, 104c), respectively.

  The drying container 101 is configured as a plug flow system so that the supplied coal flows in the room. This extruding flow is a flow of extruding this coal in the fluidizing direction so that the coal does not diffuse in the fluidizing direction in the fluidized bed S.

  Further, the drying container 101 is provided with a plurality of heat transfer tubes 106, 107, and 108 that pass through the drying container 101 from the outside and circulate in the fluidized beds S1, S2, and S3 in the drying chambers 111, 112, and 113, respectively. Has been. The heat transfer tubes 106, 107, and 108 are positioned so as to be embedded in the fluidized beds S1, S2, and S3, and the coal in the fluidized beds S1, S2, and S3 is heated and dried by the fluidized gas flowing inside. can do. In this case, the temperature of the heat transfer tubes 106, 107, 108 can be adjusted by changing the pressure of the supplied superheated steam.

  Therefore, the coal supplied to the first drying chamber 111 is fluidized by the fluidizing gas and heated by the heat transfer tube 106 to be dried. Then, the coal initially dried in the first drying chamber 111 is moved to the second drying chamber 112 through the passage opening 116 at the lower portion of the partition plate 114, and is heated by the heat transfer tube 107 here. Dried. Then, the coal dried in the second stage in the second drying chamber 112 is moved to the third drying chamber 113 through the passage opening 117 at the lower part of the partition plate 115, where it is heated by the heat transfer tube 108 to be in the latter period. Dried.

  As a result, the coal forming the fluidized beds S1, S2, and S3 of the drying chambers 111, 112, and 113 sequentially moves between the fluidized beds S1, S2, and S3 from the upstream side through the passage openings 116 and 117. Therefore, it can be made an extruded flow and is dried without being diffused in the flow direction.

  Next, the cyclone 33 separates fine particles of dry coal from the exhaust gas (fluidized gas and generated steam) discharged from the gas outlet 105 of the fluidized bed drying device 12. Therefore, an exhaust gas supply line 211 is provided from the gas discharge port 105 of the fluidized bed drying device 12 toward the upper part of the cyclone 33. The cyclone 33 is provided with a discharge pipe 212 that discharges the exhaust gas from which fine particles have been removed from below. The discharge pipe 212 is arranged along the vertical direction at the center in the cyclone 33, the discharge port 212a at the upper end is arranged at the upper part of the cyclone 33 and at the horizontal center, and the lower end is in the horizontal direction. And is bent outward from the lower part of the cyclone 33. The lower end of the discharge pipe 212 is connected to the chimney 214 via the pipe 213.

  Further, the cyclone 33 is provided with a cooling water spray device 201 at the top. The cooling water spray device 201 sprays cooling water into the cyclone 33 to lower the fine particles separated from the exhaust gas. The cooling water spray device 201 is disposed on the upper part of the cyclone 33, and a plurality of spray nozzles 215 are provided at predetermined intervals (equal intervals) in the circumferential direction on the outer peripheral side in the horizontal direction, and directed downward from each spray nozzle 215. Cooling water can be sprayed. In this case, although the spray nozzle 215 and the discharge port 212a of the discharge pipe 212 are shifted up and down, they are also shifted left and right (in the radial direction of the cyclone 33), so that the cooling water sprayed from the spray nozzle 215 is discharged. It does not enter the outlet 212a.

  The fluidizing gas supply device 202 supplies exhaust gas from which fine particles have been removed by the cyclone 33 to the fluidized bed drying device 12 as a fluidizing gas. The fluidizing gas supply device 202 includes a fluidizing gas return line 216 that connects the pipe 213 and the gas supply line 121, and a circulation blower 217 provided in the fluidizing gas return line 216. The fluidizing gas supply device 202 is provided with a heating device 203 for heating the fluidizing gas supplied to the fluidized bed drying device 12. The heating device 203 is provided downstream of the circulating blower 217 in the fluidizing gas return line 216 in the fluidizing gas flow direction. The heating device 203 is, for example, a combustion burner or a heat exchanger.

  In addition, the cyclone 33 is provided with a storage tank 221 for storing a mixed liquid containing cooling water sprayed by the cooling water spray device 201 and the descending fine particles. The storage tank 221 is provided so as to communicate with a swirl chamber in which the lower part of the cyclone 33 is reduced in diameter, and can store a mixed liquid containing coal fine particles. The storage tank 221 has a separation function for separating the waste (fine particles) that has floated with respect to the mixed liquid, and the liquid exceeding the reference surface of the stored water can be recovered as waste liquid (fine particles). it can. That is, the storage tank 221 is connected to the waste liquid tank 223 via the intermediate chamber 222, and treats the fine particles accumulated in the waste liquid tank 223 as waste. Note that the fine particles may be recycled and reused without being treated as waste.

  The storage tank 221 is provided with a cooling water circulation device 231 that supplies a liquid obtained by removing waste from the stored mixed liquid to the cooling water spray device 201 as cooling water. The cooling water circulation device 231 includes a cooling water circulation line 232 that connects the lower part of the storage tank 221 and the cooling water spray device 201, and a strainer 233 and a circulation pump 234 provided in the cooling water circulation line 232. Further, the cooling water circulation device 231 is provided with a cooling device 235 that cools the cooling water supplied to the cooling water spray device 201. The cooling device 235 is a cooling tower or a heat exchanger.

  There is provided a heat exchange device 241 that exchanges heat between the exhaust gas supplied from the fluidized bed drying device 12 to the cyclone 33 and the fluidized gas supplied to the fluidized bed drying device 12 by the fluidized gas supply device 202. The heat exchange device 241 includes a first heat exchanger 242 provided in the upper part of the cyclone 33, a second heat exchanger 243 provided in the fluidized gas return line 216, a first heat exchanger 242 and a second heat exchanger 242. A circulation line 244 through which the heat exchange medium circulates with the heat exchanger 243 and a circulation blower 245 provided in the circulation line 244 are provided. Therefore, the fluidized gas supplied to the fluidized bed drying device 12 by the fluidized gas supply device 202 can be heated by the heat of the exhaust gas supplied from the fluidized bed drying device 12 to the cyclone 33.

  Here, the operation of the wet fuel drying system of this embodiment will be described.

  In the wet fuel drying system, in the fluidized bed drying device 12, as shown in FIG. 3, coal is supplied from the coal inlet 102 to the drying container 101 and fluidized through the dispersion plate 109 from the fluidizing gas supply unit 104. By supplying the gas, fluidized beds S1, S2, and S3 having a predetermined thickness are formed above the dispersion plate 109. The coal moves the fluidized beds S1, S2, and S3 to the dry coal discharge port 103 side by the fluidizing gas, and at this time, the coal is heated and dried by receiving heat from the heat transfer tubes 106, 107, and 108.

  That is, when coal is supplied from the coal inlet 102, first, in the first drying chamber 111, fluidizing gas is supplied from the fluidizing gas supply unit 104a through the dispersion plate 109 and receives heat from the heat transfer tube 106. Thus, it is dried while flowing in the fluidized bed S1. Next, the coal that has been initially dried in the first drying chamber 111 flows into the second drying chamber 112 through the passage opening 116 of the partition plate 114. In the second drying chamber 112, the fluidizing gas is supplied from the fluidizing gas supply unit 104 b through the dispersion plate 109, and is also dried while flowing in the fluidized bed S <b> 2 by receiving heat from the heat transfer tube 107. Then, the coal whose medium-term drying is completed in the second drying chamber 112 flows to the third drying chamber 113 through the passage opening 117 of the partition plate 115. In the third drying chamber 113, the fluidizing gas is supplied from the fluidizing gas supply unit 104 c through the dispersion plate 109 and receives heat from the heat transfer tube 108, thereby being dried while flowing in the fluidized bed S <b> 3. Thus, the coal flows in the fluidized beds S1, S2 and S3 by the fluidized gas supplied while being heated by the heat transfer tubes 106, 107 and 108, and does not diffuse in the flow direction as an extruded flow. Dried.

  Thereafter, the dry coal from which the coal has been dried is discharged to the outside from the dry coal discharge port 103, and the steam generated by heating and drying the coal in the fluidized bed S rises together with the fluidized gas, and the dry coal discharge port The gas flows to the 103 side and is discharged to the outside through the gas discharge port 105.

  Exhaust gas (fluidized gas and generated steam) discharged from the gas outlet 105 of the fluidized bed drying device 12 is supplied to the cyclone 33 through the exhaust gas supply line 211. The exhaust gas supplied to the cyclone 33 is swirled inside, whereby coal fine particles are separated to the outer peripheral side, and descends by the cooling water sprayed from each spray nozzle 215 of the cooling water spray device 201. On the other hand, the exhaust gas from which the fine particles have been removed is cooled by cooling water and the vapor is condensed, and the inert gas is sucked into the discharge pipe 212 from the discharge port 212a. It is processed.

  Here, a part of the exhaust gas discharged from the cyclone 33 to the pipe 213 through the discharge pipe 212 is supplied to the fluidized bed drying apparatus 12 by the fluidizing gas supply apparatus 202 as a fluidizing gas. That is, when the circulation blower 217 is operated, a part of the exhaust gas discharged to the pipe 213 is sucked into the fluidized gas return line 216 and heated to a predetermined temperature by the heating device 203 and the heat exchange device 241 and then gas. It is sent to the supply line 121 and supplied to the fluidized bed drying apparatus 12 as fluidized gas.

  On the other hand, cooling water containing fine particles descending in the cyclone 33 and water condensed with steam are stored in the storage tank 221. In the storage tank 221, the waste (fine particles) is separated from the stored liquid mixture by floating, and the separated waste is collected in the waste liquid tank 223 through the intermediate chamber 222.

  In addition, the liquid from which the waste is removed from the mixed liquid in the storage tank 221 is supplied to the cooling water spraying apparatus 201 as cooling water by the cooling water circulating apparatus 231. At this time, the liquid flows through the cooling water circulation line 232 by the circulation pump 234, foreign matter is removed by the strainer 233, and the liquid is cooled to a predetermined temperature by the cooling device 235 before being supplied to the cooling water spray device 201.

  As described above, in the wet fuel drying system according to the first embodiment, fluidized bed drying device 12 that fluidizes and drys coal by supplying fluidized gas, and exhaust gas discharged from fluidized bed drying device 12. The cyclone 33 for separating fine coal particles (fine powder), the cooling water spray device 201 for lowering the fine particles separated by spraying the cooling water into the cyclone 33, and the exhaust gas from which the fine particles have been removed by the cyclone 33 A fluidized gas supply device 202 that supplies the fluidized gas to the fluidized bed drying device 12 as a fluidized gas and a heating device 203 that heats the fluidized gas supplied to the fluidized bed drying device 12 by the fluidized gas supply device 202 are provided. .

  Therefore, in the fluidized bed drying device 12, the coal is fluidized and dried by the supplied fluidized gas, and the exhaust gas discharged from the fluidized bed drying device 12 is separated into fine particles by the cyclone 33. The fine particles are lowered by spraying the cooling water into the cyclone 33. On the other hand, the exhaust gas from which the fine particles have been removed by the cyclone 33 is heated by the heating device 203 and then flows as a fluidizing gas by the fluidizing gas supply device 202. It will be supplied to the layer drying device 12. Therefore, fine particles can be appropriately removed from the exhaust gas and reused as fluidized gas, and the apparatus can be simplified.

  In this case, the cyclone 33 has the cooling water spraying device 201, so that one device has a dust removal function, a cooling function, and a condensation function. Therefore, cost reduction can be achieved.

  In the wet fuel drying system according to the first embodiment, the waste water is removed from the storage tank 221 that stores the liquid mixture containing the cooling water sprayed by the cooling water spray device 231 and the descending fine particles, and the liquid mixture in the storage tank 221. A cooling water circulation device 231 that supplies liquid as cooling water to the cooling water spray device 201 is provided. Therefore, a mixed liquid of cooling water, fine particles, and condensed water is stored in the storage tank 221, and the liquid from which the waste is removed from the mixed liquid of the storage tank 221 by the cooling water circulation device 231 is used as the cooling water in the cooling water spray apparatus 201. As a result, the sprayed cooling water and the water condensed from the fluidized gas can be used effectively, and the processing cost can be reduced.

  In the wet fuel drying system of the first embodiment, the cooling water circulation device 201 is provided with a cooling device 235 for cooling the cooling water supplied to the cooling water spray device. Therefore, when the liquid from which the waste has been removed by the cooling water circulation device 231 is supplied as cooling water to the cooling water spraying device 201, the cooling device 235 cools this liquid. It will be sprayed in the cyclone 33 by the apparatus 201, and dust removal, cooling, and condensation can be performed efficiently by cooling exhaust gas efficiently.

  In the wet fuel drying system according to the first embodiment, the storage tank 221 is provided with a separation function for separating the waste floating on the mixed liquid. Therefore, the fine particles of coal have a porous shape and a low specific gravity and are likely to float on water. Therefore, it is easy to separate waste by floating and separating waste from the liquid mixture. This can be performed, and simplification and cost reduction of the apparatus can be achieved.

  In the wet fuel drying system according to the first embodiment, the cyclone 33 is provided with a discharge pipe 212 for discharging the exhaust gas from which fine particles have been removed from below, and the discharge port 212a of the discharge pipe 212 is disposed at the top and in the horizontal central side. On the other hand, the spray nozzle 215 of the cooling water spray device 201 is arranged at the upper part and on the outer peripheral side in the horizontal direction. Therefore, the exhaust gas from which the fine particles have been removed by the discharge pipe 212 is discharged from the lower part of the cyclone 33, the overall height of the cyclone 33 can be lowered, and the apparatus can be made compact. In addition, the discharge port 212a of the discharge pipe 212 and the spray nozzle 215 are disposed so as to be shifted in the horizontal direction, and mixing of the cooling water into the discharge pipe 212 can be prevented.

  In the wet fuel drying system of the first embodiment, the heat exchange device 241 that performs heat exchange between the exhaust gas supplied to the cyclone 33 and the fluidized gas supplied to the fluidized bed drying device 12 by the fluidized gas supply device 202 is provided. Provided. Accordingly, the fluidizing gas can be heated by the heat of the exhaust gas, and the exhaust heat efficiency can be improved by efficiently using the heat to be discarded.

  In the wet fuel drying system of Example 1, an inert gas (nitrogen gas) is applied as the fluidizing gas. Therefore, when the fluidizing gas is an inert gas, fine particles can be appropriately removed from the exhaust gas and reused as the fluidizing gas.

  In the above-described embodiment, the inside of the drying container 101 is divided into the three drying chambers 111, 112, and 113 in the fluidized bed drying device 12, but two drying chambers or four or more drying chambers may be used. Further, the configuration and arrangement of the shape of the drying container 101, the coal inlet 102, the dry coal outlet 103, the fluidized gas supply unit 104, the gas outlet 105, and the heat transfer tubes 106, 107, 108 are limited to each embodiment. However, the fluidized bed drying device 12 can be changed as appropriate according to the installation location and application of the fluidized bed drying device 12. That is, the wet fuel drying system of the present invention does not depend on the form of the fluidized bed drying apparatus.

  FIG. 5 is a schematic side view showing a modification of the fluidized bed drying apparatus. As shown in FIG. 5, the fluidized bed drying apparatus 301 includes a drying container 301, a coal inlet 302, a dry coal outlet 303, a fluidized gas supply unit 304, a gas outlet 305, and a heat transfer tube 306. have.

  The drying container 301 is divided into an upper drying chamber 311 and a lower wind box 310 by providing a dispersion plate 309 having a plurality of through holes in the lower portion. The drying container 301 is provided with a fluidizing gas supply unit 304 that supplies fluidizing gas from the wind box 310 to the drying chamber 311 through the dispersion plate 309.

  The drying container 301 is supplied with coal from the coal inlet 302 and supplied with fluidizing gas from the fluidizing gas supply unit 304 through the wind box 310 and the dispersion plate 309, so that the drying container 301 is disposed above the dispersion plate 309. A fluidized bed S having a predetermined thickness is formed, and a free board portion F is formed above the fluidized bed S. Here, the drying container 301 includes a single drying chamber 311.

  The operation in the fluidized bed drying apparatus is the same as that described above, and a description thereof will be omitted.

  In the above-described embodiments, low-grade coal is used as the wet fuel, but even high-grade coal can be applied, and is not limited to coal, and can be used as a renewable organic organic resource. For example, it is also possible to use thinned wood, waste wood, driftwood, grass, waste, sludge, tires, and recycled fuel (pellets or chips) using these as raw materials.

  In the above-described embodiment, the fluidizing gas is supplied into the drying container 101. However, air or the like may be applied as the fluidizing gas in addition to the inert gas.

DESCRIPTION OF SYMBOLS 11 Coal feeder 12 Fluidized bed dryer 13 Pulverized coal machine 14 Coal gasifier 15 Char recovery device 16 Gas refiner 17 Gas turbine equipment 18 Steam turbine equipment 19 Generator 20 Waste heat recovery boiler 33 Cyclone 101 Drying vessel 104 Fluidization Gas supply section 105 Gas discharge port 106, 107, 108 Heat transfer pipe 201 Cooling water spray device 202 Fluidized gas supply device 203 Heating device 211 Exhaust gas supply line 212 Discharge pipe 215 Spray nozzle 216 Fluidized gas return line 221 Storage tank 231 Cooling water circulation Equipment 232 Cooling water circulation line 235 Cooling equipment 241 Heat exchange equipment S, S1, S2, S3 Fluidized bed

Claims (7)

A fluidized bed drying device for fluidizing and drying wet fuel by supplying fluidized gas;
A cyclone separating fine particles from the exhaust gas discharged from the fluidized bed drying device;
A cooling water spraying device for lowering the separated fine particles by spraying cooling water into the cyclone;
A fluidized gas supply device for supplying the fluidized bed drying device with the exhaust gas from which fine particles have been removed by the cyclone as a fluidized gas;
A heating device for heating the fluidized gas supplied to the fluidized bed drying device by the fluidized gas supply device;
A wet fuel drying system comprising:   A storage tank for storing a mixed liquid containing the cooling water sprayed by the cooling water spraying apparatus and the descending fine particles, and a liquid obtained by removing waste from the mixed liquid in the storage tank is supplied to the cooling water spraying apparatus as cooling water. A wet fuel drying system according to claim 1, further comprising a cooling water circulation device.   3. The wet fuel drying system according to claim 2, wherein the cooling water circulation device is provided with a cooling device for cooling the cooling water supplied to the cooling water spraying device.   4. The wet fuel drying system according to claim 2, wherein the storage tank has a separation function of separating the waste that has floated with respect to the mixed liquid. 5.   The cyclone is provided with a discharge pipe for discharging the exhaust gas from which fine particles have been removed from the lower part, and the discharge port of the discharge pipe is disposed at the upper side and in the horizontal central side, while the spray nozzle of the cooling water spray device The wet fuel drying system according to any one of claims 1 to 4, wherein the fuel is disposed at an upper portion and on an outer peripheral side in a horizontal direction.   The heat exchange apparatus which performs heat exchange between the exhaust gas supplied to the cyclone and the fluidized gas supplied to the fluidized bed drying apparatus by the fluidized gas supply apparatus is provided. The drying system for wet fuel according to any one of the above.   7. The wet fuel drying system according to claim 1, wherein an inert gas or low-temperature air is applied as the fluidizing gas.

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