JP2012241990A - Fluidized bed drying device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the drying efficiency of a fluidized bed drying device.SOLUTION: The fluidized bed drying device is provided with a drying container 101 in a hollow shape; a coal feed opening 102 for feeding raw coal to one end side of the drying container 101; a dry coal discharge opening 103 for discharging dry coal obtained by heating and drying the raw coal from the other end side of the drying container 101; a fluidized gas supply part 104 which supplies fluidized gas to a lower part of the drying container 101 to form a fluidized bed S with the raw coal; a gas discharge opening 105 which discharges fluidized gas and generated steam from above the raw coal feed opening 102 on the one end side of the drying container 101; and an electric heater 106 and heat transfer tubes 107, 108 which heat the raw coal of the fluidized bed S.

Description

  The present invention relates to a fluidized bed drying apparatus for drying a material to be dried by fluidizing gas.

  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, the coal is dried and then pulverized, supplied to the coal gasifier as pulverized coal, and air is taken in. The coal gas is combusted and gasified in this coal gasifier, and the product gas (combustible) 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.

  By the way, the coal used in such a coal gasification combined power generation facility is not only a high-grade coal (high-grade coal) having a high calorific value such as bituminous coal and anthracite, but also a comparison such as sub-bituminous coal and lignite. There is a low-grade coal (low-grade coal) with a low calorific value. This low-grade coal has a large amount of moisture to be brought in, and the power generation efficiency decreases due to this moisture. For this reason, in the case of low-grade coal, it is necessary to dry the coal with the above-described drying apparatus to remove moisture and then pulverize and supply the coal gasifier.

  As a drying apparatus for drying such coal, there is one described in Patent Document 1 below. The fluidized drying method and fluidized bed drying apparatus described in Patent Document 1 supply a raw material containing moisture from a raw material supply port to a supply chamber, and the fluidized gas flows through a dispersion plate in the supply chamber and the drying classification chamber. When the animal is fluidized and dried and classified into fine powder and coarse particles, the layer thickness of the fluidized bed in the supply chamber is controlled separately from the layer thickness of the fluidized bed in the dry classification chamber.

JP 2008-128524 A

  As described above, low-grade coal has a higher water content than high-grade coal, and thus fluidization failure occurs in the drying apparatus, which may cause coal drying failure. In particular, in the region close to the inlet portion, the water concentration is high and the dispersibility of the particles is not good. This may cause fluidization failure, adhesion, and accumulation near the heat transfer tube and at the bottom surface, resulting in blockage. . Therefore, it is necessary to reduce the amount of coal to be input, and there is a problem that the processing amount decreases. The fluidized drying method and fluidized bed drying apparatus described in Patent Document 1 described above are materials having a high water content by controlling the layer thickness of the fluidized bed in the supply chamber separately from the layer thickness of the fluidized bed in the drying classification chamber. Are stably dried and classified while suppressing the agglomeration of the raw material particles and the occurrence of adhesion to the apparatus. However, this technique has a problem that the moisture evaporation load per unit volume of the fluidized bed in the supply chamber is increased, and the amount of heat for properly drying the raw material is insufficient.

  The present invention solves the above-described problems, and an object thereof is to provide a fluidized bed drying apparatus capable of improving the drying efficiency.

  In order to achieve the above object, a fluidized bed drying apparatus of the present invention includes a drying container having a hollow shape, a wet fuel charging unit for charging wet fuel to one end side of the drying container, and the other end side of the drying container. A dry matter discharge unit that discharges a dry matter obtained by heating and drying the wet fuel, a fluidizing gas supply unit that forms a fluidized bed together with the wet fuel by supplying a fluidizing gas to a lower portion of the drying vessel, and the drying vessel An electric heater disposed on the side of the wet fuel input unit, and a gas discharge unit that discharges fluidized gas and generated steam from above, and a heating unit that heats the wet fuel in the fluidized bed. And a heat transfer tube disposed on the dry matter discharge part side.

  Therefore, when wet fuel is fed into the dry container from the wet fuel feed section and fluidized gas is supplied from the fluidized gas supply section to the lower part of the dry container, the wet fuel flows by the fluidized gas. A fluidized bed is formed, and the wet fuel in the fluidized bed is heated by the heating unit to be gradually dried to become a dried product, and the dried product is discharged to the outside from the dried product discharge unit. Steam generated by the drying of the wet fuel is discharged to the outside from the gas discharge unit. In this case, the electric heater arranged on the wet fuel input part side as the heating part has a heating capacity larger than that of the heat transfer tube, so that the wet fuel with a large amount of water immediately after the input is given a sufficient amount of heat by this electric heater. The wet fuel can be heated and the fluidization failure of the wet fuel, adhesion to the surroundings and accumulation can be suppressed, and the drying efficiency of the wet fuel can be improved.

  In the fluidized bed drying apparatus of the present invention, the electric heater is arranged over a predetermined range from a wall surface of the drying container where the wet fuel charging unit is provided toward the dry matter discharge unit.

  Accordingly, the wet fuel with a large amount of water introduced from the wet fuel input unit is heated by receiving an appropriate amount of heat by the electric heater arranged over a predetermined range, and the drying efficiency of the wet fuel can be improved. .

  In the fluidized bed drying apparatus of the present invention, the interval between the wires in the electric heater is set narrower than the interval between the pipes in the heat transfer tube.

  Therefore, the electric heater can give a sufficient amount of heat to the wet fuel that is supplied from the wet fuel supply portion and has a large amount of water.

  In the fluidized bed drying apparatus of the present invention, a fluidized bed temperature detection sensor that detects the temperature of the fluidized bed, and a control device that controls the electric heater based on a detection result of the fluidized bed temperature detection sensor are provided. It is said.

  Therefore, by controlling the electric heater based on the temperature of the fluidized bed, an optimal amount of heat can be applied according to the flow state of the wet fuel in the fluidized bed.

  In the fluidized bed drying apparatus of the present invention, the fluidized bed is divided into a plurality of regions for each predetermined size, and the electric heater and the fluidized bed temperature detection sensor are respectively disposed in the plurality of regions, and the control device Is characterized in that the heating temperature by the electric heater is adjusted according to the temperature of the region.

  Therefore, it becomes possible to grasp the temperature distribution in the entire fluidized bed by using a plurality of fluidized bed temperature detection sensors, and by adjusting the heating temperature by the electric heater according to the temperature of each region, an appropriate temperature can be obtained over the entire fluidized bed. And the drying efficiency of the wet fuel can be improved.

  According to the fluidized bed drying apparatus of the present invention, as the heating unit for heating the wet fuel in the fluidized bed, an electric heater disposed on the wet fuel charging unit side and a heat transfer tube disposed on the dry matter discharge unit side are provided. Therefore, the wet fuel with a large amount of water immediately after being charged is heated by being supplied with a sufficient amount of heat by an electric heater having a large heat capacity, so that the wet fuel does not fluidize properly, and adheres to and accumulates on the surroundings. The drying efficiency of the fuel can be improved.

FIG. 1 is a schematic side view showing a fluidized bed drying apparatus according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the first drying chamber in the fluidized bed drying apparatus of the present embodiment. FIG. 3 is a cross-sectional view of the second drying chamber in the fluidized bed drying apparatus of the present embodiment. FIG. 4 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.

  Exemplary embodiments of a fluidized bed drying apparatus 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 side view showing a fluidized bed drying apparatus according to an embodiment of the present invention, FIG. 2 is a sectional view of a first drying chamber in the fluidized bed drying apparatus of the present embodiment, and FIG. Sectional drawing of the 2nd drying chamber in the fluidized-bed drying apparatus of this, FIG. 4 is a schematic block diagram of the coal gasification combined cycle power generation facility to which the fluidized-bed drying apparatus of a present Example was applied.

  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 gas turbine equipment to generate electricity. 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 case, low-grade coal is used as the wet fuel supplied to the gasifier.

  In this embodiment, as shown in FIG. 4, 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 low-grade coal, and can drop a predetermined amount of low-grade coal into the coal feeder 22. The coal feeder 22 can transport the low-grade 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 low-grade coal into a predetermined size.

  The fluidized bed drying device 12 supplies drying steam (superheated steam) to the low-grade coal introduced by the coal feeder 11 so as to heat and dry the low-grade coal while flowing. Moisture contained in the graded coal can be removed. The fluidized bed drying device 12 is provided with a cooler 31 for cooling the dried low-grade coal taken out from the lower portion, and the dried and cooled dried coal is stored in the dried coal bunker 32. Further, the fluidized bed drying apparatus 12 is provided with a dry coal cyclone 33 and a dry coal electrostatic precipitator 34 for separating dry coal particles from steam taken out from above, and the dry coal particles separated from the steam are dried coal bunker. 32 is stored. The steam from which the dry coal has been separated by the dry coal electrostatic precipitator 34 is compressed by the steam compressor 35 and then supplied to the fluidized bed drying device 12 as drying steam.

  The pulverized coal machine 13 is a coal pulverizer, and pulverizes the low-grade 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 low-grade coal having a predetermined particle size or less, that is, pulverized coal. The pulverized coal after being pulverized by the pulverized coal machine 13 is separated from the conveying gas by the pulverized coal bag filters 37a and 37b and stored in the pulverized coal 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. A first nitrogen supply line 43 is connected to the coal gasifier 14, and a pulverized coal supply hopper is connected to the first nitrogen supply line 43. Charging lines 44a and 44b from 38a and 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 bin may be disposed between the dust collector 51 and the supply hopper 52, and a plurality of supply hoppers 52 may be connected to the bin. 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. Therefore, in the steam turbine facility 18, the turbine 69 is driven by the steam supplied from the exhaust heat recovery boiler 20, and the generator 19 can be driven by rotating the rotating shaft 64.

  The exhaust gas from which heat has been recovered by the exhaust heat recovery boiler 20 is freed of harmful substances by the gas purification device 74, and the purified exhaust gas is discharged from the chimney 75 to the atmosphere.

  Here, the action | operation of the coal gasification combined cycle power generation equipment 10 of a present Example is demonstrated.

  In the coal gasification combined power generation facility 10 of the present embodiment, raw coal (low-grade coal) is stored in the raw coal bunker 21 by the coal feeder 11, and the low-grade coal of the raw coal bunker 21 is supplied to the coal. The machine 22 drops the crusher 23 where it is crushed to a predetermined size. The crushed low-grade coal is heated and dried by the fluidized bed drying device 12, cooled by the cooler 31, and stored in the dry coal bunker 32. Further, the steam taken out from the upper part of the fluidized bed drying device 12 is separated into dry coal particles by the dry coal cyclone 33 and the dry coal electrostatic precipitator 34 and compressed by the steam compressor 35 before being supplied to the fluidized bed drying device 12. Returned as drying steam. On the other hand, the dry coal particles separated from the steam are stored in the dry coal bunker 32.

  The dry coal stored in the dry coal bunker 32 is fed into the pulverized coal machine 13 by the coal feeder 36, where it is pulverized into fine particles to produce pulverized coal, and through the pulverized coal bag filters 37a and 37b. And stored in the pulverized coal supply hoppers 38a and 38b. The pulverized coal stored in the pulverized coal supply hoppers 38 a and 38 b is supplied to the coal gasification furnace 14 through the first nitrogen supply line 43 by nitrogen supplied from the air separation device 42. Further, the char recovered by the char recovery device 15 described later is supplied to the coal gasifier 14 through the second nitrogen supply line 45 by nitrogen supplied from the air separation device 42. Further, the compressed air extracted from the gas turbine equipment 17 to be described later is boosted by the booster 68 and then supplied to the coal gasification furnace 14 through the compressed air supply line 41 together with oxygen supplied from the air separation device 42.

  In the coal gasification furnace 14, the supplied pulverized coal and char are combusted by compressed air (oxygen), and the pulverized coal and char are gasified to generate combustible gas (coal gas) mainly composed of carbon dioxide. Can be generated. The combustible gas is discharged from the coal gasifier 14 through the gas generation line 49 and sent to the char recovery device 15.

  In the char recovery device 15, the combustible gas is first supplied to the dust collector 51, whereby the char contained in the gas is separated from the combustible gas. The combustible gas from which the char has been separated is sent to the gas purification device 16 through the gas discharge line 53. On the other hand, the fine char separated from the combustible gas is deposited on the supply hopper 52, returned to the coal gasifier 14 through the char return line 46, and recycled.

  The combustible gas from which the char has been separated by the char recovery device 15 is subjected to gas purification by removing impurities such as sulfur compounds and nitrogen compounds in the gas purification device 16 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 is supplied from the compressed air supplied from the compressor 61 and the gas purification device 16. Combustion gas is generated by mixing with fuel gas and combusting, and the turbine 63 is driven by this combustion gas, so that the generator 19 can be driven via the rotating shaft 64 to generate power.

  The exhaust gas discharged from the turbine 63 in the gas turbine equipment 17 generates steam by exchanging heat with air in the exhaust heat recovery boiler 20, and supplies the generated steam to the steam turbine equipment 18. . In the steam turbine facility 18, the generator 69 can be driven through the rotating shaft 64 to generate electric power by driving the turbine 69 with the steam supplied from the exhaust heat recovery boiler 20.

  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.

  Hereinafter, the fluidized bed drying apparatus 12 in the coal gasification combined power generation facility 10 described above will be described in detail.

  As shown in FIGS. 1 to 3, the fluidized bed drying apparatus 12 includes a drying container 101, a raw coal charging port (wet fuel charging unit) 102, a dry coal discharging port (dry matter discharging unit) 103, and a fluidization A gas supply unit 104 (104a, 104b), a gas discharge port (gas discharge unit) 105, an electric heater 106 as a heating unit, and heat transfer tubes 107, 108 are provided.

  The drying container 101 has a hollow box shape, and a raw coal charging port 102 for charging raw coal is formed on one end side, and a dried product obtained by heating and drying raw coal is discharged to the lower portion on the other end side. A dry charcoal discharge port 103 is formed. In this case, the raw coal input port 102 and the dry coal discharge port 103 are provided one by one at the end of the drying container 101, but a plurality of them may be provided. Further, the drying container 101 is provided with a dispersion plate 109 having a plurality of openings at a predetermined distance from the bottom plate 101a in the lower portion, so that the wind box 110 is partitioned. The drying container 101 is provided with a fluidized gas supply unit 104 that supplies fluidized gas (superheated steam) 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 raw coal from the raw 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. A fluidized bed S having a predetermined thickness is formed above, and a free board portion F is formed above the fluidized bed S.

  And the drying container 101 is comprised by the 1st drying chamber 111 provided in the upstream of the flow direction of raw coal, and the 2nd drying chamber 112 provided in the downstream of the flow direction of raw coal, A partition plate 113 that partitions the first drying chamber 111 and the second drying chamber 112 is provided on the dispersion plate 109, and the first drying chamber 111 and the second drying chamber 112 communicate with each other above the partition plate 113. . In this case, the first drying chamber 111 is formed with a freeboard portion F1 and a fluidized bed S1, and is a complete mixing region for initial drying of raw coal, and the second drying chamber 112 is fluidized with the freeboard portion F2. A layer S2 is formed, which serves as an extrusion region (plug flow region) for late drying of raw coal. The first drying chamber 111 and the second drying chamber 112 have a floor area ratio of 30 to 50%: 70 to 50%, which is set to an optimum ratio according to the raw coal processing amount. When the amount of raw coal is large, the first drying chamber 111 is preferably widened, and the floor area ratio between the first drying chamber 111 and the second drying chamber 112 is 50%: 50%. Set to.

  In this case, the wind box 110 is partitioned into wind boxes 110a and 110b corresponding to the first drying chamber 111 and the second drying chamber 112, and fluidized gas supply units 104a and 104b are provided corresponding to the wind boxes 110a and 110b. It has been. And the amount of fluidization gas supplied to wind box 110a, 110b can be adjusted by adjusting the opening of the flow control valve which is not illustrated.

  That is, the first drying chamber 111 is configured such that the supplied raw coal is in a completely mixed flow in the chamber. This completely mixed flow is a flow mixed in the fluidized bed S1 formed in the first drying chamber 111 so that the moisture content (moisture content) in the raw coal becomes uniform. For this reason, in the first drying chamber 111, back-mixing occurs in the flow direction.

  Moreover, the 2nd drying chamber 112 is comprised so that the supplied raw coal may flow in the chamber. This extrusion flow is a flow in which the raw coal is pushed in the flow direction so that the raw coal does not diffuse in the flow direction in the fluidized bed S2 formed in the second drying chamber 112.

  In the first drying chamber 111, the electric heater 106 and the heat transfer tubes 107 and 108 are arranged in series along the flow direction. In this case, the electric heater 106 is disposed over a predetermined range from the wall surface of the drying vessel 101 where the raw coal inlet 102 is provided toward the dry coal outlet 103 (second drying chamber 112), and the heat transfer tube 107 is electrically connected to the electric heater 106. It is disposed between the heater 106 and the partition plate 113. The electric heater 106 is disposed over a predetermined region, so that the wiring can be heated to heat the raw coal of the fluidized bed S1. Further, the heat transfer tube 107 can be dried by heating the raw coal of the fluidized bed S1 with superheated steam flowing inside.

  That is, the electric heater 106 is supported by the plurality of first support plates 121 along the direction orthogonal to the flow direction and along the vertical direction, and a plurality of (in the present embodiment, a predetermined interval in the flow direction). 4). On the other hand, the heat transfer tubes 107 are supported by the plurality of second support plates 122 along the flow direction and along the vertical direction, and a plurality of heat transfer tubes 107 with a predetermined interval in the direction perpendicular to the flow direction (in this embodiment, 5).

  In this case, in the electric heater 106, the wiring is supported on the first support plate 121 in a wave shape up and down with a predetermined interval W1, and is arranged with a predetermined interval L1 in the flow direction. On the other hand, in the heat transfer tube 107, the pipe is supported on the second support plate 122 in a wave shape up and down with a predetermined interval W2, and is arranged with a predetermined interval L2 in a direction orthogonal to the flow direction. The intervals W1, L1 between the wires in the electric heater 106 are set to be narrower than the intervals W2, L2 between the tubes in the heat transfer tube 107.

  Further, in the first drying chamber 111, the fluidized bed S in which the electric heater 106 is disposed is partitioned into a plurality of regions by being partitioned for each predetermined size (volume). For example, the horizontal direction is partitioned into a plurality of regions and the vertical direction is partitioned into a plurality of regions, and a temperature sensor (fluidized bed temperature detection sensor) 123 that detects the temperature of the fluidized bed S is provided in each region. ing. In this case, each temperature sensor 123 is supported by the support rod 124 from the side wall (or bottom plate 101a, ceiling plate 101b) of the drying container 101.

  The ends of the plurality of electric heaters 106 are connected to the heater control unit 125, and the heating temperature by the electric heater 106 can be adjusted by the heater control unit 125. The control device 126 can input the detection results of the plurality of temperature sensors 123 and can control the heater control unit 125. Accordingly, the control device 126 can individually adjust the heating temperature of each electric heater 106 by controlling the heater control unit 125 based on the detection result of the temperature sensor 123.

  Therefore, when raw coal is introduced into the first drying chamber 111 in the drying container 101 from the raw coal introduction port 102, the raw coal is first heated by the electric heater 106 while flowing in the fluidized bed S1 by the fluidizing gas. Subsequently, it is dried by being heated by the heat transfer tube 107. As a result, the raw coal forming the fluidized bed S1 of the first drying chamber 111 can be made into a completely mixed flow, and is dried so that the moisture content (moisture content) is uniform. In the first drying chamber 111, for example, raw coal having a moisture content of about 60% can be initially dried until the moisture content becomes about 30 to 40%.

  Further, in the second drying chamber 112, a plurality of partition plates 129 along the horizontal direction perpendicular to the flow direction of the raw coal and along the vertical direction are arranged at predetermined intervals in the flow direction of the raw coal. It is attached to the wall. A plurality of heat transfer tubes 108 that pass through the drying container 101 from the outside and circulate in the fluidized bed S <b> 2 are supported by the partition plates 129. Each partition plate 129 that supports the heat transfer tube 107 has a lower end portion that is separated from the upper surface of the dispersion plate 108 so that a predetermined gap (flow port) is secured, and the upper end portion extends upward from the fluidized bed S2. The raw coal of the fluidized bed S2 can be heated and dried by the superheated steam flowing in the heat transfer tube 132.

  In this case, since the plurality of partition plates 129 are arranged at predetermined intervals in the flow direction of the raw coal, the second drying chamber 112, specifically, the fluidized bed S2 is divided into the plurality of compartments S21, The plurality of compartments S21, S22, S23, S24, and S25 are divided into S22, S23, S24, and S25, have substantially the same volume, and are formed side by side along the flow direction of the raw coal. . Therefore, the raw coal can move from the respective distribution ports through the compartments S21, S22, S23, S24, and S25 while being dried in the fluidized bed S2.

  Therefore, when raw coal that has been initially dried is supplied from the first drying chamber 111, the raw coal flows in the fluidized bed S2 by the fluidized gas, and the distribution port between each partition plate 129 and the dispersion plate 109. The compartments S21, S22, S23, S24, S25 are moved through. At this time, the raw coal is dried by being heated by the heat transfer tube 108.

  As a result, the raw coal forming the fluidized bed S2 of the second drying chamber 112 can be made into an extruded flow by sequentially moving the plurality of compartments S21, S22, S23, S24, and S25 from the upstream side. Dried without diffusing in the direction. Note that the second drying chamber 112 can dry the raw coal having a moisture content of about 30 to 40%, for example, until the moisture content becomes about 10%.

  Here, the entire operation of the fluidized bed drying apparatus 12 of the present embodiment will be described.

  In the fluidized bed drying apparatus 12, the raw coal is supplied from the raw coal inlet 102 to the drying container 101 and the fluidized gas is supplied from the fluidized gas supply unit 104 through the dispersion plate 109. A fluidized bed S having a predetermined thickness is formed above the dispersion plate 109. The raw coal moves through the fluidized bed S to the dry coal discharge port 103 side by the fluidizing gas, and is heated and dried by receiving heat from the electric heater 106 and the heat transfer tubes 107 and 108 at this time.

  In this case, the raw coal is heated and dried by the heat from the electric heater 106 and the heat transfer tubes 107 and 108 and the fluidized gas while moving from the raw coal inlet 102 to the dry coal outlet 103. The raw coal immediately after being introduced from the mouth 102 has a high moisture concentration, and there is a risk that proper drying becomes difficult. However, in this embodiment, the interior of the drying container 101 is divided into a first drying chamber 111 and a second drying chamber 112, and further, an electric power whose heating temperature can be adjusted to the raw coal input port 102 side in the first drying chamber 111. A heater 106 is provided. Therefore, the raw coal input to the first drying chamber 111 from the raw coal input port 102 is first heated by the electric heater 106 and then heated by the heat transfer tube 107.

  At this time, the plurality of temperature sensors 123 detect the temperature of the arrangement region of the electric heater 106 in the fluidized bed S1, and the control device 126 controls the heater control unit 125 based on the detection result of each temperature sensor 123. The heating temperature of each electric heater 106 is individually adjusted. For example, the heating temperature of each electric heater 106 is adjusted by the heater control unit 125 so that the temperature is set to a preset heating temperature region in the arrangement region of the electric heater 106 in the fluidized bed S1. That is, if the raw coal input from the raw coal input port 102 stays, the temperature in the staying region decreases, so the heating temperature of the electric heater 106 arranged in that region is increased. In the fluidized bed S <b> 1 of the first drying chamber 111, the raw coal becomes a completely mixed flow, and is dried so that the moisture content is substantially uniform within the region of the first drying chamber 111.

  The raw coal that has been initially dried in the first drying chamber 111 flows over the partition plate 113 to the second drying chamber 112. In the second drying chamber 112, the raw coal flows in the fluidized bed S2 by the fluidized gas, and passes through the flow port between each partition plate 129 and the dispersion plate 109 to enter the compartments S21, S22, S23, S24, and S25. Move in order. At this time, the raw coal is dried in the fluidized bed S2 without being diffused in the flow direction as an extruded flow while being heated by the heat transfer tube 108.

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

  As described above, in the fluidized bed drying apparatus of the present embodiment, the drying container 101 having a hollow shape, the raw coal charging port 102 for charging raw coal to one end side of the drying container 101, and the other end of the drying container 101 are provided. A dry coal discharge port 103 for discharging dry coal heated and dried from the raw coal from the side, and a fluidized gas supply unit 104 for forming a fluidized bed S together with the raw coal by supplying a fluidizing gas to the lower part of the drying vessel 101; A gas outlet 105 for discharging fluidized gas and generated steam from above the raw coal inlet 102 on one end side of the drying container 101, an electric heater 106 and heat transfer tubes 107, 108 for heating the raw coal of the fluidized bed S, Is provided.

  Therefore, when raw coal is introduced into the drying container 101 from the raw coal inlet 102 and fluidized gas is supplied from the lower part of the drying container 101 through the dispersion plate 107 from the fluidized gas supply unit 104, the raw coal is supplied. When fluidized gas flows, a fluidized bed S is formed. When the raw coal of the fluidized bed S moves by fluidized gas, it is heated by the heat transfer tube 106 to be dried to become dry coal. Is discharged to the outside from the dry coal discharge port 103, while steam generated by drying the fluidized gas and raw coal is discharged to the outside from the gas discharge port 105. In this case, the electric heater 106 arranged on the raw coal charging port 102 side has a heating capacity larger than that of the heat transfer tube 107, so that the raw coal with a large amount of moisture immediately after charging has a sufficient amount of heat by the electric heater 106. It can be applied and heated, and the poor fluidization of the raw coal, adhesion to the surroundings and accumulation can be suppressed, and the drying efficiency of the raw coal can be improved.

  Moreover, in the fluidized bed drying apparatus of the present embodiment, the electric heater 106 is disposed over a predetermined range from the wall surface of the drying container 101 where the raw coal input port 102 is provided toward the dry matter discharge port 103 side. Therefore, the raw coal with a large amount of water input from the raw coal input port 102 is heated by receiving an appropriate amount of heat by the electric heater 106 arranged over a predetermined range, thereby improving the drying efficiency of the raw coal. Can do.

  Further, in the fluidized bed drying apparatus of the present embodiment, the intervals W1, L1 between the wires in the electric heater 106 are set narrower than the intervals W2, L2 between the tubes in the heat transfer tube 107. Therefore, the electric heater 106 can give a sufficient amount of heat to the raw coal having a high water content introduced from the raw coal inlet 102.

  In the fluidized bed drying apparatus of the present embodiment, a temperature sensor 123 that detects the temperature of the fluidized bed S1 and a control device 126 that controls the electric heater 106 based on the detection result of the temperature sensor 123 are provided. Therefore, by controlling the electric heater 106 based on the temperature of the fluidized bed S1, an optimal amount of heat can be applied according to the flow state of the raw coal in the fluidized bed S1.

  Further, in the fluidized bed drying apparatus of the present embodiment, the fluidized bed S1 in which the electric heater 106 is disposed is divided into a plurality of regions for each predetermined size, the temperature sensors 123 are disposed in the plurality of regions, and the control device 126 is provided. The heating temperature by the electric heater 106 can be adjusted according to the temperature of each region. Therefore, it becomes possible to grasp the temperature distribution in the whole area of the fluidized bed S1 where the electric heater 106 is arranged by the plurality of temperature sensors 123, and by adjusting the heating temperature by the electric heater 106 according to the temperature of each region, It becomes possible to adjust to an appropriate temperature over the whole fluidized bed S1, and the drying efficiency of raw coal can be improved.

  In the above-described embodiment, the electric heater 106 in the fluidized bed S1 is divided into a plurality of regions. However, this number is not limited, and is appropriately determined according to the size of the drying container 101 (fluidized bed S1). You only need to set it.

  Moreover, in each Example mentioned above, although the inside of the drying container 101 was divided into the 1st drying chamber 111 and the 2nd drying chamber 112, it is good also as only the 1st drying chamber 111 or the 2nd drying chamber 112 only. Further, the configuration and arrangement of the shape of the drying container, the raw coal inlet 102, the dry coal outlet 103, the fluidized gas supply unit 104, the gas outlet 105, and the heat transfer tubes 107 and 108 are limited to each embodiment. It is not a thing, and it can change suitably according to the installation place, use, etc. of the fluidized bed drying apparatus 12. FIG.

  Moreover, in each Example mentioned above, although low grade coal was used as a wet fuel, it is applicable even if it is high grade coal, and it is not limited to coal, but can be used as an organic resource derived from renewable organisms. For example, it is also possible to use thinned wood, waste wood, driftwood, grass, waste, sludge, tires, and recycled fuel (pellets and chips) made from these raw materials. .

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 101 Drying vessel 102 Raw coal input (Wet fuel input part)
103 Dry coal discharge port (dry matter discharge part)
104 Fluidizing gas supply unit 105 Gas outlet (gas outlet)
106 Electric heater (heating unit)
107,108 Heat transfer tube (heating unit)
111 1st drying chamber 112 2nd drying chamber 121 1st support plate 122 2nd support plate 123 Temperature sensor (fluidized bed temperature detection sensor)
125 Heater control part 126 Control device 129 Partition plate F, F1, F2 Free board part S, S1, S2 Fluidized bed

Claims (5)

A drying container having a hollow shape;
A wet fuel charging unit for charging wet fuel to one end of the drying container;
A dry matter discharge unit for discharging dry matter obtained by heating and drying wet fuel from the other end of the drying container;
A fluidized gas supply unit that forms a fluidized bed with wet fuel by supplying fluidized gas to a lower portion of the drying container;
A gas discharge part for discharging fluidized gas and generated steam from above the drying container;
A heating unit for heating the wet fuel in the fluidized bed;
With
The heating unit includes an electric heater disposed on the wet fuel charging unit side and a heat transfer tube disposed on the dry matter discharge unit side.
A fluidized bed drying apparatus.   2. The fluidized bed drying apparatus according to claim 1, wherein the electric heater is disposed over a predetermined range from a wall surface of the drying container where the wet fuel charging unit is provided toward the dry matter discharge unit.   The fluidized bed drying apparatus according to claim 1 or 2, wherein an interval between wirings in the electric heater is set to be narrower than an interval between pipes in the heat transfer tube.   4. A fluidized bed temperature detection sensor for detecting the temperature of the fluidized bed, and a control device for controlling the electric heater based on a detection result of the fluidized bed temperature detection sensor. The fluidized bed drying apparatus according to claim 1.   The fluidized bed is divided into a plurality of regions for each predetermined size, and the electric heater and the fluidized bed temperature detection sensor are respectively disposed in the plurality of regions, and the control device is configured to respond to the temperature of the region. The fluidized bed drying apparatus according to claim 4, wherein a heating temperature by the electric heater is adjusted.

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