JP5693494B2 - Fluidized bed dryer - Google Patents

Description

  The present invention relates to a fluidized bed drying apparatus for drying a material to be dried by fluidizing steam or 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 are those described in Patent Documents 1 and 2 below. The fluidized drying method and fluidized bed drying apparatus described in Patent Document 1 supplies wet fuel containing moisture from a fuel supply port to a supply chamber, and is covered by fluidized gas through a dispersion plate in the supply chamber and the drying classification chamber. When the fluid is fluidized and dried and classified into fine powder and coarse particles, the bed height of the fluidized bed in the supply chamber is controlled separately from the bed height of the fluidized bed in the dry classification chamber.

  In addition, the fluidized dryer and the drying method described in Patent Document 2 are configured so that the flow rate of the heat source / fluidizing gas blown from the lower side of the gas dispersion plate just below the charging chute is below the gas dispersion plate other than the lower portion of the charging chute. It is made faster than the flow rate of the heat source and fluidizing gas blown from the side.

JP 2008-128524 A JP 2011-69609 A

  As described above, the low-grade coal has a higher moisture content than the high-grade coal, so that fluidization failure occurs in the drying device, which may cause 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.

  In the proposal described in Patent Document 1 described above, by controlling the bed height of the fluidized bed in the supply chamber separately from the bed height of the fluidized bed in the drying classification chamber, a raw material (raw coal) having a high water content is used as raw material particles. Is stably dried and classified while suppressing the occurrence of agglomeration and 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.

Further, in the proposal described in Patent Document 2, the flow rate of the heat source / fluidizing gas is set to be higher than the flow rate of the heat source / fluidizing gas blown from the lower side of the gas dispersion plate other than just below the charging chute. However, for example, low-grade coal such as lignite has a moisture content of 60% or more, which is higher than the moisture content of coal, which is high-grade coal (9-13%), so it is not sufficient to make the fluidizing gas faster. Therefore, further measures to cope with the drying of low-grade coal are eagerly desired.
Also, when water vapor is used for drying low-grade coal, water vapor condenses on the raw material particles immediately after charging, and the fluidized material particles form agglomerated particles due to condensation, and the agglomerated particles settle on the bottom of the dryer. There is a risk of causing a flow failure phenomenon.
Furthermore, in some large-capacity drying devices, heat transfer tubes are provided to promote drying. However, when raw materials with extremely high water content are supplied, they adhere to the periphery of the heat transfer tubes and become blocked. There is a risk of letting it.

  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.

The first invention of the present invention for solving the above-described problems includes a dry container having a hollow shape, a wet fuel input part for supplying wet fuel to one end side of the dry container, and the other end side of the dry container A dry matter discharge unit that discharges dry matter obtained by heating and drying the wet fuel, and fluidized steam or fluidization that forms a fluidized bed together with the wet fuel by supplying fluidized steam or fluidized gas to the lower part of the drying container. A gas supply unit; a gas discharge unit for discharging fluidized steam or fluidized gas and generated steam from above the drying container ; and at least 2 formed by dividing the drying container in the moving direction of the wet fuel in the fluidized bed. it and a more dry chamber heat transfer tubes provided in each of the drying chamber, the drying chamber bottom of the drying chamber of the wet fuel input side, in cross section corrugated, the grooves of the wave plate Formed along the moving direction of wet fuel Using a plate-shaped distribution plate, with supplying fluidizing steam or fluidizing gas, the wave plate of the dispersion plate, that the angle of the wave plate disposed above the angle of repose of the particles of the dried product The fluidized bed drying apparatus is characterized.
The second invention is characterized in that, in the first invention, the corrugated dispersion plate is arranged with an angle of the corrugated plate of 50 degrees or more.
According to a third invention, in the first or second invention, the relationship between the pitch (D ₁ ) of the crests forming the top of the corrugated dispersion plate and the pitch (D ₂ ) of the flat part is [D ₂ / (D ₁ + D ₂ )] × 100 <4%.

According to a fourth invention, in any one of the first to third inventions, a water repellent material is applied to a wall surface in the drying chamber on the wet fuel input side and a surface of the corrugated dispersion plate. It is in the fluidized bed drying apparatus characterized by this.

According to the present invention, a corrugated dispersion in which the cross-sectional shape is corrugated and the groove portion of the corrugated plate is formed along the moving direction of the wet fuel at the bottom of the drying chamber in the drying chamber on the wet fuel input portion side. Since fluidized steam or fluidized gas is supplied using a plate, the agglomerated particles are crushed and the groove portion of the corrugated plate is formed along the moving direction. It will be gone.
As a result, it is possible to avoid adhesion, blockage, and flow failure during drying on the inlet side of the wet fuel, and it is possible to make the drying apparatus more compact and stable operation by improving the drying efficiency per unit volume.

FIG. 1 is a schematic side view showing a fluidized bed drying apparatus according to Embodiment 1 of the present invention. 2 is a schematic cross-sectional view taken along line AA of FIG. 1 showing the fluidized bed drying apparatus of Example 1. FIG. FIG. 3 is a perspective view of the corrugated dispersion plate according to the first embodiment. FIG. 4 is a cross-sectional view of a corrugated dispersion plate. FIG. 5 is a schematic configuration diagram of a coal gasification combined power generation facility to which the fluidized bed drying apparatus of Example 1 is applied.

  Hereinafter, the present invention will be described in detail with reference to the 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. In addition, constituent elements in the following embodiments include those that can be easily assumed by those skilled in the art or those that are substantially the same.

  FIG. 1 is a schematic side view showing a fluidized bed drying apparatus according to Embodiment 1 of the present invention, and FIG. 5 is a schematic configuration diagram of a coal gasification combined power generation facility to which the fluidized bed drying apparatus of Embodiment 1 is applied. .

  The coal gasification combined power generation facility (IGCC: Integrated Coal Gasification Combined Cycle) of Example 1 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 purifier. 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 Example 1, as shown in FIG. 5, 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 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 this gas purification device 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 absorbing solution. 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 Example 1 is demonstrated.

  In the coal gasification combined power generation facility 10 of the first 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 input to 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 FIG. 1, 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, fluidized steam or fluidized flow. Fluidized gas supply parts (not shown) for supplying a gasified gas (hereinafter referred to as “fluidized gas”) 104a, 104b, 104c, a gas discharge port (gas discharge part) 105, a heat transfer tube (heating part) 106a, 106b, 106c.

  The drying container 101 has a hollow box shape, and is formed with a raw coal charging port 102 for charging raw coal (wet fuel) on one end side, and dried by heating and drying raw coal on a lower portion on the other end side. A dry charcoal discharge port 103 for discharging the material is formed, and the raw coal is dried by an extrusion method (plug flow) inside the drying container 101. 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. In addition, the drying container 101 is provided with a dispersion plate 108 having a plurality of openings at a predetermined distance from the bottom plate 101a in the lower portion, so that an air box 109 is partitioned. The drying container 101 supplies fluidized gas (superheated steam) 104a, 104b, and 104c to the upper side of the dispersion plates 108A, 108B, and 108C through the air boxes 109a, 109b, and 109c on the bottom plate 101a side. A supply unit is provided. Further, in the drying container 101, a gas discharge port 105 for discharging the fluidized gas 104 and generated steam is formed in the ceiling plate 101b on the dry coal discharge port 103 side.

  In the drying container 101, raw coal is supplied from the raw coal inlet 102, and fluidized gases 104a, 104b, 104c are supplied from a fluidized gas supply unit through wind boxes 109a, 109b, 109c and dispersion plates 108A, 108B, 108C. Is supplied, fluidized beds S1, S2, and S3 having a predetermined thickness are formed above the dispersion plates 108A, 108B, and 108C, and a free board portion F is formed above the fluidized bed S. .

  And the drying container 101 of a present Example has the 1st drying chamber 111a with which the inside was provided in the upstream of the flow direction of raw coal, and the 2nd drying chamber 111b sequentially provided in the downstream of the flow direction of raw coal. And the third drying chamber 111c, the first drying chamber 111a on the dispersion plate 108A, the second drying chamber 111b on the dispersion plate 108B, and the third drying chamber 111c on the dispersion plate 108C and a partition plate that partitions them. 113 is provided.

  The partition plate 113 is installed at a predetermined interval from the upper surface of the dispersion plate 108, and an opening (flow port) 113 a through which raw coal passes is formed in a part of the partition plate 113. Note that the shape and the opening size of the opening 113a may be appropriately changed or changed depending on the wet state of the raw coal. Further, the upper end portion of the partition plate 113 is positioned so as to extend above the fluidized beds S1, S2, and S3 so that the flowd raw coal does not flow over the partition plate 113 to the downstream side. Yes.

  The first drying chamber 111a, the second drying chamber 111b, and the third drying chamber 111c communicate with each other above the partition plate 113. In this case, the first drying chamber 111a is a region in which the free board portion F1 and the fluidized bed S1 are formed to perform initial drying (preliminary drying) of the raw coal, and the second drying chamber 111b is the free board portion F2. And a fluidized bed S2 is formed, which is an area for drying (mid-term drying). The third drying chamber 111c is a region where the freeboard portion F3 and the fluidized bed S3 are formed, and the latter drying (finish drying) of the raw coal is performed.

  In this case, the air box 109 is partitioned into air boxes 109a to 109c corresponding to the first drying chamber 111a to the third drying chamber 111c, and a fluidizing gas supply unit is provided corresponding to the air boxes 109a to 109c. . And the gas quantity of the fluidization gas 104a-104c supplied in the wind boxes 109a-109c can be adjusted by adjusting the opening degree of the flow regulating valve which is not illustrated.

2 is a schematic cross-sectional view taken along line AA of FIG. 1 showing the fluidized bed drying apparatus of Example 1. FIG. FIG. 3 is a perspective view of the corrugated dispersion plate according to the first embodiment. FIG. 4 is a cross-sectional view of a corrugated dispersion plate.
As shown in FIGS. 2 and 3, the dispersion plate installed at the bottom of the first drying chamber 111a in the drying container 101 is a corrugated dispersion plate 108A, and its cross-sectional shape is corrugated. The channel of the corrugated groove 108b is formed along the flow direction of the wet fuel (FIG. 1).
Further, the corrugated plate angle (α) is preferably not less than the angle of repose of the particles, for example, preferably not less than 50 degrees.

As a result, since it is a corrugated dispersion plate 108A, the aggregated particles falling on the top 108a are crushed, and the groove 108b of the corrugated plate is formed along the flow direction, so the flow is good, The fixed part will be lost.
As a result, it is possible to avoid adhesion, blockage, and flow failure during drying on the inlet side of the wet fuel, and it is possible to make the drying apparatus more compact and stable operation by improving the drying efficiency per unit volume.

  That is, in the case of the conventional flat-shaped dispersion plate 108B installed in the second drying chamber 111b, particles with poor flow are deposited between the ejection holes or the eye plates where the fluidized gas 104b is ejected. Then, the poorly flowable particles are immobilized and form a flow inhibition.

  On the other hand, by using the corrugated dispersion plate 108A at the bottom of the first drying chamber 111a, this flow failure is eliminated and the flow is moved along the groove portion 108b. Reduction can be achieved.

Further, the wall surface of the first drying chamber 111a and the dispersion plate 108A are made of a water repellent material that hardly causes dew condensation.
As a water-repellent material that is difficult to condense, for example, a Teflon (registered trademark) coating or a Teflon (registered trademark) sheet is used and applied to or pasted on the wall surface and the dispersion plate.
Alternatively, a sheet containing silica (SiO ₂ ) may be attached.

  By applying the water repellent material to the surface such as the wall surface in this way, the wall surface does not get wet and particles on the wall surface slide, and aggregation due to condensation is reduced.

Further, as shown in FIG. 4, the pitches D ₁ and D ₂ between the peak and the flat part need to ensure the differential pressure between the plates necessary for maintaining a good flow state, but should be changed as appropriate. Can do.
It is preferable that the relationship [D ₂ / (D ₁ + D ₂ )] × 100 is set to 4% or less so that the fluid state is suitably maintained.

  In the present embodiment, the flow rates of the fluidized gases 104a, 104b, and 104c are the same. However, the present invention is not limited to this, and depending on the moisture content of the wet fuel to be introduced, the drying chambers 111a, 111b, and 111c are supplied. The flow speeds of these may be different.

Here, in this embodiment, the floor area ratio of the first drying chamber 111a, the second drying chamber 111b, and the third drying chamber 111c is made uniform, but the present invention is not limited to this, and these ratios are changed as appropriate. May be.
The optimum ratio is set according to the amount of raw coal treated. For example, when the amount of raw coal treated is large, the first drying chamber 111a is preferably widened and appropriately set. .

  Here, the whole operation | movement of the fluidized bed drying apparatus 12 of Example 1 is demonstrated.

  In the fluidized bed drying device 12, as shown in FIGS. 1 and 2, the raw coal is supplied from the raw coal inlet 102 to the drying container 101, and the dispersion plates 108A, 108B, For example, fluidized gases 104a, 104b, and 104c of superheated steam are supplied through 108C, so that fluidized beds S1, S2, and S3 having a predetermined thickness are formed above the dispersion plates 108A to 108C. The raw coal of the wet fuel gradually moves the fluidized beds S1, S2, and S3 to the dry coal discharge port 103 side in a compacted state by the fluidized gases 104a, 104b, and 104c, and at this time, the heat transfer tubes 106a, 106b, and 106c It is heated and dried by receiving heat.

In this case, the raw coal is heated and dried by the heat from the heat transfer tubes 106a to 106c and the fluidized gases 104a to 104c while moving from the raw coal inlet 102 to the dry coal outlet 103. The raw coal immediately after being introduced from 102 has a high moisture concentration, and there is a possibility that proper drying becomes difficult.
However, in this embodiment, the dispersion plate at the bottom of the first drying chamber 111a on the wet fuel charging unit 102 side is a corrugated dispersion plate 108A, so that the aggregated particles of the wet fuel are crushed and flowed. It is possible to reduce defects. Therefore, the raw coal input to the first drying chamber 111a from the raw coal input port 102 does not stay at the bottom of the drying chamber, and is preferably first dried (preliminary drying) in the first drying chamber 111a.

  The raw coal which has been initially dried in the first drying chamber 111a is pushed away at the opening 113a of the partition plate 113 and gradually flows into the second drying chamber 111b. In the second drying chamber 111b, the raw coal flows in the fluidized bed S2 by the fluidized gas 104b, and is heated by the heat transfer pipe 106b in the fluidized bed S2 and becomes an extruded flow without being diffused in the flow direction. Is done.

Thereafter, the dry coal from which the raw coal has been dried is pushed away at the opening 113a of the partition plate 113 and gradually flows into the third drying chamber 111c. In the third drying chamber 111c, the raw coal flows in the fluidized bed S3 by the fluidized gas 104c, and finish drying is performed while being heated by the heat transfer tube 106c in the fluidized bed S3.
Thereafter, the dry coal is discharged to the outside from the dry coal discharge port 103, and the steam generated by heating and drying the raw coal in the fluidized beds S1, S2, and S3 rises together with the fluidizing gas, and the dry coal discharge port 103 To the outside and discharged from the gas discharge port 105 to the outside.

  Thus, in the fluidized bed drying apparatus of Example 1, the drying container 101 having a hollow shape, the raw coal charging port 102 for charging raw coal into one end side of the drying container 101, and the other end of the drying container 101 are provided. The dry coal discharge port 103 for discharging the dry coal heated and dried from the raw coal from the side and the fluidized gas 104a, 104b, 104c are supplied to the lower part of the drying vessel 101, thereby the fluidized beds S1, S2, S3 together with the raw coal. The fluidized gas supply section to be formed, the gas outlet 105 for discharging fluidized gas and generated steam from above the raw coal inlet 102 on one end side of the drying vessel 101, and the moving fuel in the fluidized bed move in the moving direction. The container 101 is divided to form at least two (three in this embodiment) drying chambers 111a, 111b, and 111c, and the wet fuel in the fluidized beds S1, S2, and S3 is heated in each of the drying chambers. The heat transfer tubes 106a, 106b, 106c are provided, and the cross-sectional shape is corrugated at the bottom of the drying chamber in the first drying chamber 111a on the wet fuel charging portion 102 side, and the groove portion of the corrugated plate is wet fuel. The fluidizing gas 104a is supplied using a corrugated dispersion plate 108A formed along the moving direction.

  Accordingly, raw coal is introduced into the drying container 101 from the raw coal inlet 102, and fluidized gases 104a, 104b, and 104c from the fluidizing gas supply section pass through the dispersion plates 108A, 108B, and 108C from the lower portion of the drying container 101. When supplied, the raw coal flows by the fluidized gases 104a, 104b, 104c to form fluidized beds S1, S2, S3. When the raw coal in the fluidized beds moves by the fluidized gas, the heat transfer tube 106a , 106b and 106c are dried to become dry charcoal, and this dry charcoal is discharged to the outside from the dry charcoal discharge port 103, while steam generated by drying the fluidized gas and raw coal is gas. It is discharged from the discharge port 105 to the outside.

At this time, although the raw coal immediately after being input from the raw coal input portion 102 has a large amount of moisture, the cross-sectional shape is corrugated at the bottom of the drying chamber in the first drying chamber 111a, and the groove portion of the corrugated plate has By supplying the fluidizing gas 104a using the corrugated dispersion plate 108A formed along the moving direction of the wet fuel, in the preliminary drying of this raw coal, fluidization failure, adhesion to the surroundings and deposition. Then, it is forced to flow into the second drying chamber 111b and the third drying chamber 111c, and intermediate drying and finishing are performed here, so that the drying efficiency of the raw coal can be improved.
As a result, it is possible to avoid adhesion, clogging, and poor flow in the drying in the first drying chamber 111a on the inlet side of the wet fuel, and the drying efficiency per unit volume can be improved and the drying apparatus can be made compact and stable. It becomes possible.

  In this embodiment, the fluidized bed for drying the raw coal is used as an extrusion (plug flow) method, but the present invention is not limited to this, and can be applied to a complete mixing method in which the fluidized bed is completely mixed. Alternatively, the initial drying may be a complete mixing method and the final drying may be an extrusion (plug flow) method.

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)
104a, 104b, 104c Fluidized gas 105 Gas outlet (gas outlet)
106a, 106b, 106c Heat transfer tube (heating unit)
108A Corrugated plate-like dispersion plate 111a First drying chamber 111b Second drying chamber 111c Third drying chamber 113 Partition plate F1, F2, F3 Free board portion S1, S2, S3 Fluidized bed

Claims (4)

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 steam or fluidized gas supply unit that forms a fluidized bed with wet fuel by supplying fluidized steam or fluidized gas to a lower portion of the drying container;
A gas discharge part for discharging fluidized steam or fluidized gas and generated steam from above the drying container;
A heat transfer tube provided in each of the drying chambers of at least two or more drying chambers formed by dividing a drying container in the moving direction of the wet fuel in the fluidized bed,
Using a corrugated dispersion plate in which the cross-sectional shape is corrugated and the groove portion of the corrugated plate is formed along the moving direction of the wet fuel at the bottom of the drying chamber inside the drying chamber on the wet fuel input side. Supplying vaporized or fluidized gas ,
The fluidized bed drying apparatus, wherein the corrugated dispersion plate is arranged such that the angle of the corrugated plate is equal to or greater than the repose angle of the particles of the dried product.   In claim 1,
  The fluidized bed drying apparatus, wherein the corrugated dispersion plate is disposed with a corrugated plate angle of 50 degrees or more. In claim 1 or 2,
  The pitch of the crests that form the top of the corrugated dispersion plate (D ₁ ) And the pitch of the flat part (D ₂ ) Is [D ₂ / (D ₁ + D ₂ ]] Fluidized bed dryer characterized by satisfying x100 <4%. In any one of Claims 1 thru | or 3 ,
A fluidized bed drying apparatus, wherein a water-repellent material is applied to a wall surface in the drying chamber on the wet fuel input side and a surface of the corrugated dispersion plate.

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