AU2012232314A1

AU2012232314A1 - Fluidized bed drying device

Info

Publication number: AU2012232314A1
Application number: AU2012232314A
Authority: AU
Inventors: Koji Ohura
Original assignee: Mitsubishi Heavy Industries Ltd
Current assignee: Mitsubishi Heavy Industries Ltd
Priority date: 2011-03-22
Filing date: 2012-03-14
Publication date: 2013-10-10
Anticipated expiration: 2032-03-14
Also published as: AU2012232314B9; WO2012128151A1; AU2012232314B2; JP5848014B2; JP2012197976A

Abstract

A fluidized bed drying device is provided with: a drying container (101) that forms a hollow shape; a raw coal introduction port (102) at one end of the drying container (101) through which raw coal is introduced; a dried coal discharge port (103) that discharges from the other end of the drying container (101) the dried coal that results when the raw coal is heated and dried; a fluidizing gas supply port (104) that supplies a fluidizing gas to the lower part of the drying container (101) to form, together with the raw coal, a fluidized bed (S); a gas discharge port (105) that discharges the fluidizing gas and generated steam from a location higher than the raw coal introduction port (102) at one end of the drying container (101); and a heat transfer pipe (106) that heats the raw coal in the fluidized bed (S). A control device (125) adjusts the degree of opening of a flow volume adjustment valve (114) of a gas discharge line (113) on the basis of the temperature of the fluidized bed (S) as detected by a first temperature sensor (121), and thus changes the dew-point temperature by changing the pressure inside the drying container (101), which enables improved drying efficiency.

Description

Docket No. PMHA-13046-PCT 1 DESCRIPTION FLUID BED DRYING APPARATUS Field [0001] The present invention relates to a fluid bed 5 drying apparatus that dries a subject drying material by a fluidizing gas in a fluidized state. Background [0002] For example, an integrated coal gasification combined cycle is a power generating facility that gasifies 10 coal and generates power by the combination with a combined cycle power generation technique. This power generating facility aims at high efficiency and high environment property compared to a conventional coal fired power generation technique. The integrated coal gasification 15 combined cycle has much merit that coal existing as rich resources may be used. Also, it is known that the more merit is obtained with an increase in the number of the application coal types. [0003] The conventional integrated coal gasification 20 combined cycle generally includes a coal supply device, a drying device, a coal gasification furnace, a gas purification device, a gas turbine facility, a steam turbine facility, an exhausted heat recovery boiler, a gas purification device, and the like. Accordingly, coal is 25 dried and milled, and the coal is supplied as pulverized coal into the coal gasification furnace. At this time, air is supplied into the coal gasification furnace, and the coal inside the coal gasification furnace becomes a combustion gas, so that a product gas (combustible gas) is 30 produced. Then, the product gas is purified and is supplied to the gas turbine facility. Here, the product gas is burned to thereby produce a hot and pressurized combustion gas, and the turbine is driven by the combustion Docket No. PMHA-13046-PCT 2 gas. A flue gas which is produced after driving the turbine passes through the exhausted heat recovery boiler so that thermal energy is collected from the flue gas, and steam is produced and is supplied to the steam turbine 5 facility so as to drive the turbine. In this way, power generation is performed. Meanwhile, the flue gas from which the thermal energy is collected passes through the gas purification device so that a harmful substance is removed from the flue gas, and is discharged to the 10 atmosphere through a stack. [0004] By the way, the coal which is used in the integrated coal gasification combined cycle may be not only coal of high quality (high-grade coal) such as bituminous coal or smokeless coal generating a large amount of heat, 15 but also coal of low quality (low-grade coal) such as subbituminous coal or brown coal generating a comparatively low amount of heat. However, since the low-grade coal carries a large amount of moisture therein, the power generation efficiency is degraded by the moisture. For 20 this reason, in a case of the low-grade coal, there is a need to conduct a process in which the coal is dried by the above-described drying device so as to remove the moisture therefrom, is milled, and then is supplied to the coal gasification furnace. 25 [0005] As such a drying device for drying the coal, a drying device disclosed in Patent Literature 1 is known. In a method and a device for controlling a fluid bed dryer disclosed in Patent Literature 1, a flue gas which is a heat source is introduced as a heat source and a fluidizing 30 gas into a fluid bed dryer so as to dry a wet raw material, and a part of the gas introduced into a lower portion thereof is guided to the vicinity of a flue gas outlet in a bypassing manner. Here, in order to stabilize the fluid Docket No. PMHA-13046-PCT 3 bed, the FBD introduction gas amount, the processing amount, and the drying degree are set to predetermined values. Then, in order to prevent the dew condensation of a flue gas system and a circulation system, the relative humidity 5 of the flue gas of the FBD outlet is set. Moreover, the temperature of the flue gas as the heat source is measured, and an FBD introduction gas temperature, a bypassing flue gas amount, a circulating flue gas amount, and a flue gas amount of the heat source are calculated and controlled as 10 control amounts in response to a change in the temperature. Citation List Patent Literature [0006] Patent Literature 1: Japanese Laid-open Patent Publication No. 10-253251 15 Summary Technical Problem [0007] In the method and the device for controlling the fluid bed dryer of Patent Literature 1, the temperature of the flue gas which is introduced as the fluidizing gas and 20 the heat source into the fluid bed dryer so as to dry the wet raw material is measured, and the fluid bed dryer introduction gas temperature, the bypassing flue gas amount, the circulating flue gas amount, and the flue gas amount of the heat source are controlled in response to a change in 25 the temperature. However, since the wet raw material input into the fluid bed dryer or the dryer body has a large thermal capacity, the response time is extended. Accordingly, even when the temperature or the amount of the flue gas is adjusted, it is not possible to change the 30 temperature inside the fluid bed dryer at an early timing. Also, it is difficult to keep the desired processing amount and the desired drying degree in a stable operation state at all times.

Docket No. PMHA-13046-PCT 4 [0008] The invention is made to solve the above described problems, and it is an object of the invention to provide a fluid bed drying apparatus capable of improving drying efficiency. 5 Solution to Problem [0009] According to a fluid bed drying apparatus of the present invention in order to solve the above problems, it is characterized by including: a drying container formed in a hollow shape; a wet raw material input unit for inputting 10 a wet raw material to one end side of the drying container; a dry material discharge unit for discharging a dry material obtained by heating and drying the wet raw material from the other end side of the drying container; a fluidizing gas supply unit for supplying a fluidizing gas 15 to a lower portion of the drying container so as to form a fluid bed along with the wet raw material; a gas discharge unit for discharging the fluidizing gas and product steam from the upside of the wet raw material input unit at one end side of the drying container; a heating unit for 20 heating the wet raw material of the fluid bed; a dew-point temperature changing device for changing a dew-point temperature inside the drying container; a fluid bed temperature detecting sensor for detecting the temperature of the fluid bed; and a control device for controlling the 25 dew-point temperature changing device based on a detection result of the fluid bed temperature detecting sensor. [0010] Accordingly, when the wet raw material is supplied from the wet raw material input unit into the drying container and the fluidizing gas is supplied from 30 the fluidizing gas supply unit into the lower portion of the drying container, the wet raw material is fluidized by the fluidizing gas so as to form the fluid bed. Then, the wet raw material of the fluid bed is heated and dried by Docket No. PMHA-13046-PCT 5 the heating unit so as to become the dry material, and the dry material is discharged from the dry material discharge unit to the outside. Meanwhile, the steam which is produced by drying the fluidizing gas and the wet raw 5 material is discharged from the gas discharge unit to the outside. At this time, the fluid bed temperature detecting sensor detects the temperature of the fluid bed. When the temperature of the fluid bed changes, the control device changes the dew-point temperature inside the drying 10 container by controlling the dew-point temperature changing device. Then, the wet raw material drying degree inside the drying container becomes constant, and the stable wet raw material drying process may be performed at all times, so that the drying efficiency may be improved. 15 [0011] According to the fluid bed drying apparatus of the present invention, it is characterized that the dew point temperature changing device is a decompressor for changing a pressure inside the drying container, and the control device is suitable for controlling the decompressor 20 based on the temperature of the fluid bed. [0012] Accordingly, since the temperature of the fluid bed is defined by the dew-point temperature depending on the partial steam pressure inside the drying container, the deviation between the temperature of the fluid bed and the 25 dew-point temperature inside the drying container may be maintained at a predetermined value by changing the pressure inside the drying container based on the temperature of the fluid bed, and hence the stable wet raw material drying process may be performed at all times. 30 [0013] According to the fluid bed drying apparatus of the present invention, it is characterized that the control device is suitable for controlling the decompressor so that the pressure inside the drying container decreases when the Docket No. PMHA-13046-PCT 6 temperature of the fluid bed decreases. [0014] Accordingly, the deviation between the temperature of the fluid bed and the dew-point temperature inside the drying container may be easily maintained at a 5 predetermined value by decreasing the pressure inside the drying container when the temperature of the fluid bed decreases. [0015] According to the fluid bed drying apparatus of the present invention, it is characterized that the 10 fluidizing gas supply unit is suitable for supplying steam and a non-condensable gas as a fluidizing gas to the lower portion of the drying container, the dew-point temperature changing device is a device for controlling the fluidizing gas supply unit so that a steam concentration inside the 15 drying container is adjusted, and the control device is suitable for controlling the steam concentration adjusting device based on the temperature of the fluid bed. [0016] Accordingly, since the temperature of the fluid bed is defined by the dew-point temperature of the steam 20 depending on the partial steam pressure inside the drying container, the deviation between the temperature of the fluid bed and the dew-point temperature inside the drying container may be maintained at a predetermined value by adjusting the steam concentration inside the drying 25 container based on the temperature of the fluid bed, and hence the stable wet raw material drying process may be performed at all times. [0017] According to the fluid bed drying apparatus of the present invention, it is characterized that the control 30 device is suitable for controlling the steam concentration adjusting device so that the steam concentration inside the drying container decreases when the temperature of the fluid bed decreases.

Docket No. PMHA-13046-PCT 7 [0018] Accordingly, the deviation between the temperature of the fluid bed and the dew-point temperature inside the drying container may be easily maintained at a predetermined value by decreasing the steam concentration 5 inside the drying container when the temperature of the fluid bed decreases. [0019] According to the fluid bed drying apparatus of the present invention, it is characterized that the control device is suitable for increasing a non-condensable gas 10 supply amount when the temperature of the fluid bed decreases. [0020] Accordingly, since the non-condensable gas supply amount is increased when the temperature of the fluid bed decreases, the fluidizing gas amount inside the drying 15 container increases, and hence the fluidization of the wet raw material may be promoted. Thus, the drying efficiency may be improved. [0021] According to the fluid bed drying apparatus of the present invention, it is characterized that the control 20 device is suitable for decreasing a steam supply amount and increasing a non-condensable gas supply amount when the temperature of the fluid bed decreases so that a fluidizing gas amount is maintained at a constant value. [0022] Accordingly, since the steam supply amount is 25 decreased and the non-condensable gas supply amount is increased when the temperature of the fluid bed decreases, the fluidizing gas amount inside the drying container is maintained at a constant amount, and the pressure acting on the drying container does not excessively increase, so that 30 the safety may be improved. Advantageous Effects of Invention [0023] According to the fluid bed drying apparatus of the invention, since the fluid bed drying apparatus Docket No. PMHA-13046-PCT 8 includes the dew-point temperature changing device which changes the dew-point temperature inside the drying container, the fluid bed temperature detecting sensor which detects the temperature of the fluid bed, and the control 5 device which controls the dew-point temperature changing device based on the detection result of the fluid bed temperature detecting sensor, the wet raw material drying degree inside the drying container becomes constant, and the stable wet raw material drying process may be performed 10 at all times, so that the drying efficiency may be improved. Brief Description of Drawings [0024] FIG. 1 is a schematic configuration diagram illustrating an integrated coal gasification combined cycle that employs a fluid bed drying apparatus according to a 15 first embodiment of the invention. FIG. 2 is a schematic diagram illustrating the fluid bed drying apparatus of the first embodiment. FIG. 3 is a graph illustrating a dew-point temperature with respect to a pressure inside a container. 20 FIG. 4 is a schematic diagram illustrating a fluid bed drying apparatus according to a second embodiment of the invention. FIG. 5 is a graph illustrating a dew-point temperature with respect to a steam concentration inside a drying 25 container. FIG. 6 is a schematic side view illustrating a fluid bed drying apparatus according to a third embodiment of the invention. Description of Embodiments 30 First Embodiment [0026] FIG. 1 is a schematic configuration diagram illustrating an integrated coal gasification combined cycle that employs a fluid bed drying apparatus according to a Docket No. PMHA-13046-PCT 9 first embodiment of the invention, FIG. 2 is a schematic diagram illustrating the fluid bed drying apparatus of the first embodiment, and FIG. 3 is a graph illustrating a dew point temperature with respect to a pressure inside a 5 container. [0027] The Integrated Coal Gasification Combined Cycle (IGCC) of the first embodiment adopts an air combustion type in which a coal gas is produced inside a gasification furnace by using air as an oxidation agent and supplies the 10 coal gas purified by a gas purification device as a fuel gas to a gas turbine facility so as to generate power. That is, the integrated coal gasification combined cycle of the embodiment is a power generating facility of an air combustion (air blow) type. In this case, low-grade coal 15 is used as a wet raw material supplied to the gasification furnace. [0028] In the first embodiment, as illustrated in FIG. 1, an integrated coal gasification combined cycle 10 includes a coal supply device 11, a fluid bed drying apparatus 12, a 20 coal pulverizer (mill) 13, a coal gasification furnace 14, a char recovery unit 15, a gas purification device 16, a gas turbine facility 17, a steam turbine facility 18, a generator 19, and an exhausted heat recovery boiler (HRSG: Heat Recovery Steam Generator) 20. 25 [0029] The coal supply device 11 includes a raw coal bunker 21, a coal feeder 22, and a crusher 23. The raw coal bunker 21 may store low-grade coal, and inputs a predetermined amount of the low-grade coal into the coal feeder 22. The coal feeder 22 conveys the low-grade coal 30 input from the raw coal bunker 21 by a conveyor or the like, and inputs the low-grade coal into the crusher 23. The crusher 23 may crush the input low-grade coal into a predetermined size.

Docket No. PMHA-13046-PCT 10 [0030] The fluid bed drying apparatus 12 is used to heat and dry the low-grade coal in a fluidized state by supplying drying steam (superheated steam) to the low-grade coal input by the coal supply device 11, and may remove 5 moisture contained in the low-grade coal. Then, the fluid bed drying apparatus 12 is equipped with a cooler 31 which cools the low-grade coal of the drying agent extracted from the lower portion thereof, and the dry coal of the drying and cooling agent is stored in a dry coal bunker 32. 10 Further, the fluid bed drying apparatus 12 is equipped with a dry coal cyclone 33 which separates the particles of the dry coal from the steam extracted from the upper portion thereof and an electronic dry coal precipitator 34, and the particles of the dry coal separated from the steam are 15 stored in the dry coal bunker 32. Furthermore, the steam from which the dry coal is separated by the electronic dry coal precipitator 34 is compressed by a steam compressor 35, and is supplied as drying steam to the fluid bed drying apparatus 12. 20 [0031] The coal pulverizer 13 is a coal mill, and produces pulverized coal by milling the low-grade coal (the dry coal) dried by the fluid bed drying apparatus 12 into fine particles. That is, when the dry coal stored in the dry coal bunker 32 is input to the coal pulverizer 13 by a 25 coal feeder 36, the coal pulverizer mills the dry coal into pulverized coal having a predetermined particle diameter or less. Then, the pulverized coal which is milled by the coal pulverizer 13 is separated from the carrier gas by pulverized coal bag filters 37a and 37b and is stored in 30 pulverized coal supply hoppers 38a and 38b. [0032] To the coal gasification furnace 14, the pulverized coal which is processed by the coal pulverizer 13 is supplied and char (the unburned portion of coal) Docket No. PMHA-13046-PCT 11 which is collected by the char recovery unit 15 is supplied. [0033] That is, the coal gasification furnace 14 is connected with a compressed air supply line 41 from the gas turbine facility 17 (compressor 61) so that the air 5 compressed by the gas turbine facility 17 may be supplied thereto. An air separating device 42 is used to produce separate nitrogen and oxygen from the air in the atmosphere, a first nitrogen supply line 43 is connected to the coal gasification furnace 14, and the first nitrogen supply line 10 43 is connected with coal supply lines 44a and 44b from the pulverized coal supply hoppers 38a and 38b. Further, a second nitrogen supply line 45 is also connected to the coal gasification furnace 14, and the second nitrogen supply line 45 is connected with a char return line 46 from 15 the char recovery unit 15. Further, an oxygen supply line 47 is connected to the compressed air supply line 41. In this case, the nitrogen is used as a carrier gas for the coal and the char, and the oxygen is used as an oxidation agent. 20 [0034] The coal gasification furnace 14 is, for example, an entrained bed gasification furnace, and is used to burn and gasify the coal, the char, the air (the oxygen), or the moisture vapor as the gasifying agent supplied thereinto and generates a combustible gas (a product gas and a coal 25 gas) mainly including carbon dioxide, so that a gasification reaction occurs using the combustible gas as a gasifying agent. Furthermore, the coal gasification furnace 14 is equipped with a foreign matter removing device 48 which removes foreign matter mixed with the 30 pulverized coal. In this case, the coal gasification furnace 14 is not limited to the entrained bed gasification furnace, and may be also a fluid bed gasification furnace or a fixed bed gasification furnace. Then, in the coal Docket No. PMHA-13046-PCT 12 gasification furnace 14, a combustible gas generation line 49 is installed toward the char recovery unit 15, so that the combustible gas including the char may be discharged therethrough. In this case, the gas generation line 49 may 5 be equipped with a gas cooler, and the combustible gas may be cooled to a predetermined temperature and be supplied to the char recovery unit 15. [0035] The char recovery unit 15 includes a precipitator 51 and a supply hopper 52. In this case, the precipitator 10 51 includes one or plural bag filters or cyclones, and hence may separate the char included in the combustible gas produced by the coal gasification furnace 14. Then, the combustible gas from which the char is separated is sent to the gas purification device 16 through a gas discharge line 15 53. The supply hopper 52 is used to store the fine char separated from the combustible gas in the precipitator 51. Furthermore, a bin may be disposed between the precipitator 51 and the supply hopper 52 and a plurality of the supply hoppers 52 may be connected to the bin. Then, the char 20 return line 46 from the supply hopper 52 is connected to the second nitrogen supply line 45. [0036] The gas purification device 16 performs gas purification on the combustible gas from which the char is separated by the char recovery unit 15 by removing 25 impurities such as a sulfur compound or a nitrogen compound. Then, the gas purification device 16 produces a fuel gas by purifies the combustible gas and supplies the result to the gas turbine facility 17. Furthermore, in the gas purification device 16, since a sulfur content (H 2 S) is 30 still included in the combustible gas from which the char is separated, the sulfur content is collected as gypsum by the removal using amine absorbent and is effectively used. [0037] The gas turbine facility 17 includes the Docket No. PMHA-13046-PCT 13 compressor 61, a combustor 62, and a turbine 63, and the compressor 61 and the turbine 63 are connected to each other by a rotary shaft 64. The combustor 62 is connected with a compressed air supply line 65 from the compressor 61, 5 and is connected with a fuel gas supply line 66 from the gas purification device 16, so that the turbine 63 is connected with a combustion gas supply line 67. Further, the gas turbine facility 17 is equipped with the compressed air supply line 41 which extends from the compressor 61 to 10 the coal gasification furnace 14, and a booster 68 is provided in the course of the compressed air supply line. Accordingly, in the combustor 62, the compressed air supplied from the compressor 61 is mixed with the fuel gas supplied from the gas purification device 16 and is burned. 15 Thus, in the turbine 63, the generator 19 may be driven by rotating the rotary shaft 64 by the produced combustion gas. [0038] The steam turbine facility 18 includes a turbine 69 which is connected to the rotary shaft 64 in the gas turbine facility 17, and the generator 19 is connected to 20 the base end of the rotary shaft 64. The exhausted heat recovery boiler 20 is provided in a flue gas line 70 from the gas turbine facility 17 (the turbine 63), and is used to produce steam by the heat exchange between air and the high-temperature flue gas. For this reason, a steam supply 25 line 71 and a steam recovery line 72 are provided between the exhausted heat recovery boiler 20 and the turbine 69 of the steam turbine facility 18, and a condenser 73 is provided in the steam recovery line 72. Accordingly, in the steam turbine facility 18, the turbine 69 is driven by 30 the steam supplied from the exhausted heat recovery boiler 20, and the generator 19 may be driven by the rotation of the rotary shaft 64. [0039] Then, the flue gas of which the heat is collected Docket No. PMHA-13046-PCT 14 in the exhausted heat recovery boiler 20 passes through a gas purification device 74 so as to remove a toxic material therefrom, and the purified flue gas is discharged from a stack 75 to the atmosphere. 5 [0040] Here, the operation of the integrated coal gasification combined cycle 10 of the first embodiment will be described. [0041] According to the integrated coal gasification combined cycle 10 of the first embodiment, in the coal 10 supply device 11, the raw coal (low-grade coal) is stored in the raw coal bunker 21, and the low-grade coal of the raw coal bunker 21 is input to the crusher 23 by the coal feeder 22 so that the low-grade coal is milled into a predetermined size. Then, the milled low-grade coal is 15 heated and dried by the fluid bed drying apparatus 12, is cooled by the cooler 31, and is stored in the dry coal bunker 32. Further, the steam which is extracted from the fluid bed drying apparatus 12 passes through the dry coal cyclone 33 and the electronic dry coal precipitator 34 so 20 that the particles of the dry coal are separated. Then, the result is compressed by the steam compressor 35 and is returned as drying steam to the fluid bed drying apparatus 12. Meanwhile, the particles of the dry coal separated from the steam are stored in the dry coal bunker 32. 25 [0042] The dry coal which is stored in the dry coal bunker 32 is input to the coal pulverizer 13 by the coal feeder 36. Here, the dry coal is milled into fine particles to thereby produce the pulverized coal, and is stored in the pulverized coal supply hoppers 38a and 38b 30 through the pulverized coal bag filters 37a and 37b. The pulverized coal which is stored in the pulverized coal supply hoppers 38a and 38b is supplied to the coal gasification furnace 14 through the first nitrogen supply Docket No. PMHA-13046-PCT 15 line 43 by the nitrogen supplied from the air separating device 42. Further, the char which is collected by the char recovery unit 15 to be described later is supplied to the coal gasification furnace 14 through the second 5 nitrogen supply line 45 by the nitrogen supplied from the air separating device 42. Further, the compressed air which is extracted from the gas turbine facility 17 to be described later is boosted by the booster 68, and is supplied to the coal gasification furnace 14 through the 10 compressed air supply line 41 along with the oxygen supplied from the air separating device 42. [0043] In the coal gasification furnace 14, the supplied pulverized coal and char are burned by the compressed air (the oxygen), and the pulverized coal and the char are 15 gasified, thereby producing the combustible gas (the coal gas) mainly including carbon dioxide. Then, the combustible gas is discharged from the coal gasification furnace 14 through the gas generation line 49 and is sent to the char recovery unit 15. 20 [0044] In the char recovery unit 15, the combustible gas is first supplied to the precipitator 51, and the precipitator 51 separates the char included in the combustible gas. Then, the combustible gas from which the char is separated is sent to the gas purification device 16 25 through the gas discharge line 53. Meanwhile, the fine char which is separated from the combustible gas is deposited on the supply hopper 52, and is returned to the coal gasification furnace 14 through the char return line 46 so as to be recovered. 30 [0045] The combustible gas from which the char is separated by the char recovery unit 15 passes through the gas purification device 16 so that impurities such as a sulfur compound or a nitrogen compound are removed and the Docket No. PMHA-13046-PCT 16 gas is purified, thereby producing a fuel gas. Then, in the gas turbine facility 17, when the compressor 61 produces the compressed air and supplies the compressed air to the combustor 62, the combustor 62 mixes the compressed 5 air supplied from the compressor 61 with the fuel gas supplied from the gas purification device 16 and burns the mixed result to thereby produce a combustion gas. Then, the turbine 63 is driven by the combustion gas, and the generator 19 is driven through the rotary shaft 64, thereby 10 generating power. [0046] Then, the flue gas which is discharged from the turbine 63 in the gas turbine facility 17 exchanges heat with air in the exhausted heat recovery boiler 20 so as to produce steam, and the produced steam is supplied to the 15 steam turbine facility 18. In the steam turbine facility 18, the turbine 69 is driven by the steam supplied from the exhausted heat recovery boiler 20, and hence power may be generated by driving the generator 19 through the rotary shaft 64. 20 [0047] Subsequently, in the gas purification device 74, the flue gas which is purified by removing the toxic material of the flue gas discharged from the exhausted heat recovery boiler 20 is discharged to the atmosphere from the stack 75. 25 [0048] Hereinafter, the fluid bed drying apparatus 12 of the integrated coal gasification combined cycle 10 will be described in detail. [0049] As illustrated in FIG. 2, the fluid bed drying apparatus 12 includes a drying container 101, a raw coal 30 input port (wet raw material input unit) 102, a dry coal discharge port (dry material discharge unit) 103, a fluidizing gas supply port (fluidizing gas supply unit) 104, a gas discharge port (gas discharge unit) 105, and a heat Docket No. PMHA-13046-PCT 17 transfer pipe (heating unit) 106. [0050] The drying container 101 is formed in a hollow box shape, where one end side thereof is equipped with the raw coal input port 102 which inputs the raw coal 5 therethrough and the other end side thereof is equipped with the dry coal discharge port 103 which discharges the dry material obtained by heating and drying the raw coal therethrough. Further, the lower portion of the drying container 101 is equipped with a dispersion plate 107 10 having plural openings and separated from the bottom plate by a predetermined distance, and the bottom plate is equipped with the fluidizing gas supply port 104 which supplies the fluidizing gas (superheated steam) into the drying container 101 therethrough. In this case, plural 15 fluidizing gas supply ports 104 are provided in the longitudinal direction of the drying container 101, but the number of the fluidizing gas supply ports may be one. Moreover, the upper portion of the drying container 101 near the dry coal discharge port 103 is equipped with the 20 gas discharge port 105 which discharges the fluidizing gas and the product steam therethrough. [0051] Since the raw coal is supplied from the raw coal input port 102 into the drying container 101 and the fluidizing gas is supplied from the fluidizing gas supply 25 port 104 thereinto through the dispersion plate 107, a fluid bed S having a predetermined thickness is formed at the upper side of the dispersion plate 107 and a freeboard F is formed at the upper side of the fluid bed S. Then, the heat transfer pipe 106 is disposed so as to penetrate 30 the drying container 101 from the outside while circulating inside the fluid bed S, and the raw coal may be heated and dried by the superheated steam flowing through the heat transfer pipe 106.

Docket No. PMHA-13046-PCT 18 [0052] In the drying container 101, a fluidizing gas supply line 111 is provided for each fluidizing gas supply port 104, and a flowrate adjustment valve 112 is attached to the fluidizing gas supply line 111. Further, in the 5 drying container 101, a gas discharge line 113 is provided for the gas discharge port 105, and a flowrate adjustment valve 114 and a fan 115 are attached to the gas discharge line 113. Moreover, in the drying container 101, the heat transfer pipe 106 is disposed inside the fluid bed S, but a 10 flowrate adjustment valve 116 is attached to the superheated steam supply side of the heat transfer pipe 106. [0053] Further, the drying container 101 is equipped with a first temperature sensor (fluid bed temperature detecting sensor) 121 which detects the temperature of the 15 fluid bed S and a second temperature sensor 122 which detects the temperature of the freeboard F. Moreover, the drying container 101 is equipped with a pressure sensor 123 which detects the pressure of the drying container 101. [0054] To the control device 125, the temperature Ti of 20 the fluid bed S detected by the first temperature sensor 121, the temperature T2 of the freeboard F detected by the second temperature sensor 122, and the pressure P of the drying container 101 detected by the pressure sensor 123 are input. Further, the control device 125 may adjust the 25 amount of the fluidizing gas supplied from each fluidizing gas supply port 104 into the drying container 101 through the fluidizing gas supply line 111 by adjusting the opening degree of the flowrate adjustment valve 112. Further, the control device 125 may adjust the steam amount (the 30 fluidizing gas amount + the product steam amount) of the steam discharged from the inside of the drying container 101 into the gas discharge line 113 through the gas discharge port 105 by adjusting the opening degree of the Docket No. PMHA-13046-PCT 19 flowrate adjustment valve 114 or the number of revolutions of the fan 115. Moreover, the control device 125 may adjust the amount of the superheated steam flowing through the heat transfer pipe 106 so as to adjust the amount of 5 heating the fluid bed S by adjusting the opening degree of the flowrate adjustment valve 116. [0055] Then, in the embodiment, the dew-point temperature inside the drying container 101 is changed by adjusting the pressure inside the drying container 101 in 10 response to a change in temperature at the fluid bed S. In this case, a decompressor is used as a dew-point temperature changing device which changes the dew-point temperature inside the drying container 101. Specifically, the flowrate adjustment valve 114 provided in the gas 15 discharge line 113 is employed. That is, when the opening degree of the flowrate adjustment valve 112 is set to a predetermined opening degree, a predetermined amount of the fluidizing gas is supplied through the fluidizing gas supply line 111 and the fan 115 rotates by a predetermined 20 number of revolutions. Also, when the opening degree of the flowrate adjustment valve 114 is set to a predetermined opening degree, the pressure inside the drying container 101 (the entire pressure) is maintained at a predetermined pressure at the time of discharging a predetermined amount 25 of the steam inside the drying container 101. [0056] When the opening degree of the flowrate adjustment valve 114 is increased in the operation state, the amount of the steam discharged from the inside of the drying container 101 increases, and hence the pressure 30 inside the drying container 101 may be decreased. Meanwhile, when the opening degree of the flowrate adjustment valve 114 is decreased in the above-described operation state, the amount of the steam discharged from Docket No. PMHA-13046-PCT 20 the inside of the drying container 101 decreases, and hence the pressure inside the drying container 101 may be increased. Furthermore, in the example herein, the pressure inside the drying container 101 is adjusted by the 5 adjustment of the opening degree of the flowrate adjustment valve 114. However, the pressure inside the drying container 101 may be adjusted by adjusting the number of revolutions of the fan 115 through an operation of setting the opening degree of the flowrate adjustment valve 114 to 10 a constant value or zero. [0057] Then, when the pressure inside the drying container 101 increases or decreases, the dew-point temperature inside the drying container 101 may be increased or decreased. In this case, since the 15 temperature of the fluid bed S is defined by the dew-point temperature of the steam depending on the partial steam pressure inside the drying container 101, the deviation between the temperature of the fluid bed S and the dew point temperature inside the drying container may be 20 maintained at a predetermined value by the change of the pressure inside the drying container 101 based on the temperature of the fluid bed S, and hence the raw coal of the fluid bed S may be heated by a constant heating degree at all times. 25 [0058] Specifically, the control device 125 changes the dew-point temperature inside the drying container 101 by adjusting the pressure inside the drying container 101 through the adjustment of the opening degree of the flowrate adjustment valve 114 based on the detection result 30 of the first temperature detecting sensor 121. That is, the control device 125 increases the opening degree of the flowrate adjustment valve 114 so as to decrease the pressure inside the drying container 101 when the Docket No. PMHA-13046-PCT 21 temperature of the fluid bed S decreases. [0059] Here, the operation of the fluid bed drying apparatus 12 of the first embodiment will be described. [0060] In the fluid bed drying apparatus 12, since the 5 raw coal is input from the raw coal input port 102 to the drying container 101 and the fluidizing gas is supplied from the fluidizing gas supply port 104 thereinto through the dispersion plate 107, the fluid bed S having a predetermined thickness is formed at the upper side of the 10 dispersion plate 107. The raw coal is moved toward the dry coal discharge port 103 in the fluid bed S by the fluidizing gas. At this time, the raw coal is heated and dried by the heat from the heat transfer pipe 106. In this case, the raw coal is heated and dried by the heat from the 15 heat transfer pipe 106 while being moved from the raw coal input port 102 to the dry coal discharge port 103. Specifically, the raw coal immediately after input from the raw coal input port 102 becomes a preheated state, and hence the moisture thereof substantially does not evaporate. 20 Then, when the raw coal enters the drying zone over the preheating zone, the evaporation of the moisture starts and the evaporation amount thereof gradually increases to the maximal evaporation amount. The evaporation amount decreases as it approaches the dry coal discharge port 103. 25 [0061] Then, the dry coal obtained by drying the raw coal is discharged from the dry coal discharge port 103 to the outside, and the steam which is produced by heating and drying the raw coal at the fluid bed S rises along with the fluidizing gas and is discharged from the gas discharge 30 port 105 to the outside. [0062] At this time, as illustrated in FIGS. 2 and 3, the control device 125 supplies a predetermined amount of the fluidizing gas through the fluidizing gas supply line Docket No. PMHA-13046-PCT 22 111 by setting the opening degree of the flowrate adjustment valve 112 to a predetermined opening degree. Meanwhile, the control device 125 rotates the fan 115 by a predetermined number of revolutions and sets the opening 5 degree of the flowrate adjustment valve 114 to a predetermined opening degree, so that a predetermined amount of the steam inside the drying container 101 is discharged. In such an operation state of the fluid bed drying apparatus 12, the temperature Ti of the fluid bed S 10 inside the drying container 101 is maintained at 110 0 C and the pressure (entire pressure) is maintained at 100 kPa. In this case, since the intersection point A between the pressure P inside the drying container 101 and the temperature Ti of the fluid bed S may be defined so as to 15 set the deviation Ta of the dew-point temperature inside the drying container 101 with respect to the temperature Ti of the fluid bed S inside the drying container 101, the sufficient heating and drying amount of the raw coal may be ensured. 20 [0063] When the raw coal supply amount increases or the moisture content of the raw coal increases in the operation state of the fluid bed drying apparatus 12, the temperature Ti of the fluid bed S decreases. At this time, when the control device 125 detects, for example, a state where the 25 temperature Ti of the fluid bed S decreases from 110 0 C to 105 0 C, the control device increases the opening degree of the flowrate adjustment valve 114. Then, since the amount of the steam discharged from the inside of the drying container 101 increases, the pressure inside the drying 30 container 101 decreases, and hence the dew-point temperature inside the drying container 101 decreases. In this case, since the intersection point B between the Docket No. PMHA-13046-PCT 23 pressure P inside the drying container 101 and the temperature Ti of the fluid bed S may be defined so as to set the deviation Tb of the dew-point temperature inside the drying container 101 with respect to the temperature Ti 5 of the fluid bed S inside the drying container 101 as in the deviation Ta of the above-described operation state even when the temperature Ti of the fluid bed S decreases, the sufficient heating and drying amount of the raw coal is ensured. 10 [0064] That is, the control device 125 sets the pressure P inside the drying container 101 satisfying the relation of the deviation Ta = Tb and adjusts the opening degree of the flowrate adjustment valve 114 so as to obtain the pressure P inside the drying container 101. It is 15 desirable to set the relation of the temperature Ti of the fluid bed S, the dew-point temperature, and the pressure P as a map in advance in response to the state of the fluid bed drying apparatus 12. [0065] Then, when the raw coal of the fluid bed S is 20 heated and dried so that the temperature Ti of the fluid bed S increases, the control device 125 ensures a predetermined deviation between the temperature Ti inside the drying container 101 and the dew-point temperature by decreasing the opening degree of the flowrate adjustment 25 valve 114 in a manner opposite to the above-described manner. [0066] In this way, the fluid bed drying apparatus of the first embodiment includes the drying container 101 which is formed in a hollow box shape, the raw coal input 30 port 102 which inputs the raw coal to one end side of the drying container 101 therethrough, the dry coal discharge port 103 which discharges the dry coal obtained by heating and drying the raw coal from the other end side of the Docket No. PMHA-13046-PCT 24 drying container 101, the fluidizing gas supply port 104 which supplies the fluidizing gas to the lower portion of the drying container 101 so as to form the fluid bed S along with the raw coal, the gas discharge port 105 which 5 discharges the fluidizing gas and the product steam from the upside of the raw coal input port 102 at one end side of the drying container 101, and the heat transfer pipe 106 which heats the raw coal of the fluid bed S, where the control device 125 changes the dew-point temperature by 10 changing the pressure P inside the drying container 101 through the adjustment of the opening degree of the flowrate adjustment valve 114 of the gas discharge line 113 based on the temperature Ti of the fluid bed S detected by the first temperature sensor 121. 15 [0067] Accordingly, when the raw coal is input from the raw coal input port 102 into the drying container 101 and the fluidizing gas is supplied from the fluidizing gas supply port 104 thereinto through the dispersion plate 107 from the lower portion of the drying container 101, the raw 20 coal is fluidized by the fluidizing gas so as to form the fluid bed S. When the raw coal of the fluid bed S is moved by the fluidizing gas, the raw coal is heated and dried by the heat transfer pipe 106 so as to become the dry coal. Then, the dry coal is discharged from the dry coal 25 discharge port 103 to the outside and the steam which is produced by drying the fluidizing gas and the raw coal is discharged from the gas discharge port 105 to the outside. At this time, when the temperature Ti of the fluid bed S changes, the control device 125 changes the dew-point 30 temperature by adjusting the pressure P inside the drying container 101 through the adjustment of the opening degree of the flowrate adjustment valve 114. Then, the raw coal drying degree inside the drying container 101 becomes Docket No. PMHA-13046-PCT 25 constant, and the stable raw coal drying process may be performed at all times, so that the drying efficiency may be improved. [0068] In this case, the control device 125 changes the 5 dew-point temperature by adjusting the pressure P inside the drying container 101 through the adjustment of the opening degree of the flowrate adjustment valve 114 based on the temperature Ti of the fluid bed S. Specifically, when the temperature Ti of the fluid bed S decreases, the 10 control device 125 decreases the pressure P inside the drying container 101 by increasing the opening degree of the flowrate adjustment valve 114. [0069] Accordingly, since the temperature of the fluid bed S is defined by the dew-point temperature depending on 15 the partial steam pressure inside the drying container 101, the deviation between the temperature Ti of the fluid bed S and the dew-point temperature inside the drying container 101 may be maintained at a predetermined value through the adjustment of the pressure P inside the drying container 20 101 based on the temperature Ti of the fluid bed S, and hence the stable raw coal drying process may be performed at all times. Second Embodiment [0070] FIG. 4 is a schematic diagram illustrating a 25 fluid bed drying apparatus according to a second embodiment of the invention, and FIG. 5 is a graph illustrating the dew-point temperature with respect to the steam concentration inside the drying container. Furthermore, the same reference sign will be given to the same component 30 as that of the above-described embodiment, and the detailed description thereof will not be repeated. [0071] In the second embodiment, as illustrated in FIG. 4, the fluid bed drying apparatus 12 includes the drying Docket No. PMHA-13046-PCT 26 container 101, the raw coal input port 102, the dry coal discharge port 103, the fluidizing gas supply port 104, the gas discharge port 105, and the heat transfer pipe 106. [0072] In the drying container 101, the fluidizing gas 5 supply line 111 is provided for each fluidizing gas supply port 104. Then, a steam supply line 131 is provided, and is equipped with a flowrate adjustment valve 132. Also, a non-condensable gas supply line 133 is provided, and is equipped with a flowrate adjustment valve 134. Thus, two 10 lines 131 and 133 are joined to each other so as to form the fluidizing gas supply line 111. Further, the steam supply line 131 and the non-condensable gas supply line 133 are equipped with flowmeters 135 and 136 which are positioned at the upstream side in relation to the 15 respective flowrate adjustment valves 132 and 134 and adjust the steam supply amount and the non-condensable gas supply amount. Furthermore, the non-condensable gas herein indicates, for example, a flue gas, an argon gas, a nitrogen gas, and the like. 20 [0073] Further, the drying container 101 is equipped with the gas discharge line 113 for the gas discharge port 105, and is attached with a flowmeter 137. Further, the flowrate adjustment valve 116 is attached to the superheated steam supply side of the heat transfer pipe 106. 25 Further, the drying container 101 is equipped with the first temperature sensor 121 which detects the temperature of the fluid bed S and the second temperature sensor 122 which detects the temperature of the freeboard F. [0074] To the control device 125, the temperature Ti of 30 the fluid bed S detected by the first temperature sensor 121 and the temperature T2 of the freeboard F detected by the second temperature sensor 122 are input. Further, the control device 125 may adjust the amount of the superheated Docket No. PMHA-13046-PCT 27 steam supplied from the fluidizing gas supply port 104 into the drying container 101 through the steam supply line 131 and the fluidizing gas supply line 111 by adjusting the opening degree of the flowrate adjustment valve 132. 5 Further, the control device 125 may adjust the amount of the non-condensable gas supplied from the fluidizing gas supply port 104 into the drying container 101 through the non-condensable gas supply line 133 and the fluidizing gas supply line 111 by adjusting the opening degree of the 10 flowrate adjustment valve 134. [0075] Then, in the embodiment, the dew-point temperature inside the drying container 101 is changed by adjusting the steam concentration inside the drying container 101 in response to a change in the temperature of 15 the fluid bed S. In this case, as the dew-point temperature changing device which changes the dew-point temperature inside the drying container 101, the steam concentration adjusting device is used. Specifically, the flowrate adjustment valve 134 provided in the non 20 condensable gas supply line 133 is employed. That is, the flowrate adjustment valve 132 provided in the steam supply line 131 is set to a predetermined opening degree so as to supply a predetermined amount of the superheated steam through the fluidizing gas supply line 111. Then, the 25 flowrate adjustment valve 134 provided in the non condensable gas supply line 133 is closed so as to maintain the steam concentration inside the drying container 101 at 100%. [0076] When the flowrate adjustment valve 134 is opened 30 by a predetermined opening degree in the operation state, the non-condensable gas is supplied into the drying container 101, so that the steam concentration inside the drying container 101 may be decreased. Furthermore, since Docket No. PMHA-13046-PCT 28 the steam is produced inside the drying container 101 by drying the raw coal, it is desirable to adjust the non condensable gas amount inside the drying container 101 in consideration of the product steam amount. That is, the 5 dew-point temperature inside the drying container 101 may be changed by adjusting the concentration of the steam discharged from the drying container 101 in response to a change in the temperature of the fluid bed S. [0077] Here, the steam concentration is adjusted by 10 supplying the non-condensable gas into the drying container 101 through the adjustment of the opening degree of the flowrate adjustment valve 134. However, at this time, the superheated steam amount may be decreased by decreasing the opening degree of the flowrate adjustment valve 132 15 provided in the steam supply line 131. That is, the amount of the fluidizing gas supplied into the drying container 101 may be maintained at a constant value by setting the non-condensable gas increase amount to be equal to the superheated steam decrease amount. Further, in a case 20 where the raw coal inside the drying container 101 is not sufficiently fluidized, the entire fluidizing gas amount may be increased in a manner such that the amount of the superheated steam from the steam supply line 131 is not decreased or the superheated steam decrease amount becomes 25 smaller than the non-condensable gas increase amount when the amount of the non-condensable gas supplied from the non-condensable gas supply line 133 increases. [0078] Then, when the steam concentration inside the drying container 101 increases or decreases, the dew-point 30 temperature inside the drying container 101 may be increased or decreased. In this case, since the temperature of the fluid bed S is defined by the dew-point temperature of the steam depending on the partial steam Docket No. PMHA-13046-PCT 29 pressure inside the drying container 101, the deviation between the temperature of the fluid bed S and the dew point temperature inside the drying container 101 may be maintained at a predetermined value by changing the steam 5 concentration inside the drying container 101 based on the temperature of the fluid bed S, and hence the raw coal of the fluid bed S may be uniformly heated at all times. [0079] Specifically, the control device 125 changes the dew-point temperature inside the drying container 101 by 10 adjusting the steam concentration inside the drying container 101 through the adjustment of the opening degrees of the flowrate adjustment valves 132 and 134 based on the detection result of the first temperature detecting sensor 121. That is, when the temperature of the fluid bed S 15 decreases, the control device 125 decreases the steam concentration by supplying the non-condensable gas into the drying container 101 while increasing the opening degree of the flowrate adjustment valve 134. [0080] Here, the operation of the fluid bed drying 20 apparatus 12 of the second embodiment will be described. [0081] In the fluid bed drying apparatus 12, since the raw coal is supplied from the raw coal input port 102 to the drying container 101 and the fluidizing gas is supplied from the fluidizing gas supply port 104 thereinto through 25 the dispersion plate 107, the fluid bed S having a predetermined thickness is formed at the upper side of the dispersion plate 107. The raw coal is moved in the fluid bed S by the fluidizing gas toward the dry coal discharge port 103. At this time, the raw coal is heated and dried 30 by the heat from the heat transfer pipe 106. In this case, the raw coal is heated and dried by the heat from the heat transfer pipe 106 while being moved from the raw coal input port 102 to the dry coal discharge port 103. Specifically, Docket No. PMHA-13046-PCT 30 the raw coal immediately after input into the raw coal input port 102 becomes a preheated state, so that the moisture thereof substantially does not evaporate. When the raw coal enters the drying zone over the preheating 5 zone, the evaporation of the moisture starts and gradually increases to the maximal state, and the evaporation decreases as it approaches the dry coal discharge port 103. [0082] Then, the dry coal obtained by drying the raw coal is discharged from the dry coal discharge port 103 to 10 the outside, and the steam which is produced by heating and drying the raw coal of the fluid bed S rises along with the fluidizing gas so as to be discharged to the outside from the gas discharge port 105. [0083] At this time, as illustrated in FIGS. 4 and 5, 15 when the control device 125 sets the opening degree of the flowrate adjustment valve 132 to a predetermined opening degree so that a predetermined amount of the superheated steam (fluidizing gas) is supplied from the steam supply line 131 through the fluidizing gas supply line 111, a 20 predetermined amount of the steam is extruded and discharged from the gas discharge line 113. In the operation state of the fluid bed drying apparatus 12, the temperature Ti of the fluid bed S inside the drying container 101 is maintained at 110 0 C and the pressure 25 (entire pressure) is maintained at 100 kPa. In this case, since the intersection point C between the steam concentration C inside the drying container 101c and the temperature Ti of the fluid bed is defined so as to set the deviation Tc of the dew-point temperature inside the drying 30 container 101 with respect to the temperature Ti of the fluid bed S inside the drying container 101, the sufficient heating and drying amount in the raw coal is ensured. [0084] When the raw coal supply amount increases or the Docket No. PMHA-13046-PCT 31 moisture content of the raw coal increases in the operation state of the fluid bed drying apparatus 12, the temperature Ti of the fluid bed S decreases. At this time, when the control device 125 detects, for example, a state where the 5 temperature Ti of the fluid bed S decreases from 110 0 C to 105 0 C, the control device increases the opening degree of the flowrate adjustment valve 134 and decreases the opening degree of the flowrate adjustment valve 132. Then, since the non-condensable gas inside the drying container 101 10 increases and the superheated steam amount decreases, the steam concentration inside the drying container 101 decreases and the dew-point temperature inside the drying container 101 decreases. In this case, since the intersection point D between the steam concentration C 15 inside the drying container 101 (the outlet) and the temperature Ti of the fluid bed S is defined so as to set the deviation Td of the dew-point temperature inside the drying container 101 with respect to the temperature Ti of the fluid bed S inside the drying container 101 as in the 20 deviation Tc of the above-described operation state even when the temperature Ti of the fluid bed S decreases, the sufficient heating and drying amount in the raw coal is ensured. [0085] That is, the control device 125 sets the steam 25 concentration C inside the drying container 101 (the outlet) satisfying the relation of the deviation Tc = Td and adjusts the opening degrees of the flowrate adjustment valves 132 and 134 so as to obtain the steam concentration C inside the drying container 101c. It is desirable to set 30 the relation of the temperature Ti of the fluid bed S, the dew-point temperature, and the steam concentration C as a map in advance in response to the state of the fluid bed drying apparatus 12. Further, the control device 125 may Docket No. PMHA-13046-PCT 32 conduct an operation of calculating the product steam amount inside the drying container 101 based on the measurement results of the respective flowmeters 135, 136, and 137, obtaining the steam concentration inside the 5 drying container 101, that is, the gas discharge line 113, and performing a feed-back control based on the steam concentration. [0086] Then, when the raw coal of the fluid bed S is heated and dried so that the temperature Ti of the fluid 10 bed S increases, the control device 125 increases the opening degree of the flowrate adjustment valve 132 and decreases the opening degree of the flowrate adjustment valve 134 in a manner opposite to the above-described manner so as to ensure a predetermined deviation between 15 the temperature Ti and the dew-point temperature inside the drying container 101. [0087] In this way, in the fluid bed drying apparatus of the second embodiment, the steam supply line 131 is provided at the lower portion of the drying container 101 20 and is attached with the flowrate adjustment valve 132. Also, the non-condensable gas supply line 133 is provided and is attached with the flowrate adjustment valve 134. Then, the control device 125 changes the dew-point temperature by changing the steam concentration C inside 25 the drying container 101c through the adjustment of the opening degrees of the flowrate adjustment valves 132 and 134 based on the temperature of the fluid bed S detected by the first temperature sensor 121. [0088] Accordingly, when the temperature Ti of the fluid 30 bed S changes, the control device 125 changes the dew-point temperature by changing the steam concentration C inside the drying container 101c through the adjustment of the opening degrees of the flowrate adjustment valves 132 and Docket No. PMHA-13046-PCT 33 134. Then, the raw coal drying degree inside the drying container 101 becomes constant, and the stable raw coal drying process may be performed at all times, so that the drying efficiency may be improved. 5 [0089] In this case, the control device 125 changes the dew-point temperature by adjusting the steam concentration C inside the drying container 101 through the adjustment of the opening degrees of the flowrate adjustment valves 132 and 134 based on the temperature Ti of the fluid bed S. 10 Specifically, when the temperature Ti of the fluid bed S decreases, the control device 125 decreases the steam concentration C inside the drying container 101 by increasing the opening degree of the flowrate adjustment valve 134. 15 [0090] Accordingly, since the temperature of the fluid bed S is defined by the dew-point temperature of the steam depending on the partial steam pressure inside the drying container 101, the deviation between the temperature Ti of the fluid bed S and the dew-point temperature inside the 20 drying container 101 may be maintained at a predetermined value through the adjustment of the steam concentration inside the drying container 101 based on the temperature of the fluid bed S, and hence the stable raw coal drying process may be performed at all times. 25 [0091] Further, in the fluid bed drying apparatus of the second embodiment, when the temperature of the fluid bed S decreases, the control device 125 increases the non condensable gas supply amount by increasing the opening degree of the flowrate adjustment valve 134. Accordingly, 30 since the fluidizing gas amount inside the drying container 101 increases, the fluidization of the raw coal may be promoted, and hence the drying efficiency may be improved. [0092] Further, in the fluid bed drying apparatus of the Docket No. PMHA-13046-PCT 34 second embodiment, when the temperature of the fluid bed S decreases, the control device 125 decreases the superheated steam supply amount by decreasing the opening degree of the flowrate adjustment valve 132 and increasing the non 5 condensable gas supply amount by increasing the opening degree of the flowrate adjustment valve 134, thereby maintaining the fluidizing gas amount at a constant value. Accordingly, the fluidizing gas amount inside the drying container 101 is maintained at a constant value, the 10 pressure acting on the drying container 101 does not excessively increases, and hence the safety may be improved. Third Embodiment [0093] FIG. 6 is a schematic side view illustrating a fluid bed drying apparatus according to a third embodiment 15 of the invention. Furthermore, the same reference sign will be given to the same component as that of the above described embodiment, and the detailed description thereof will not be repeated. [0094] The third embodiment is an embodiment obtained by 20 the combination of the first embodiment and the second embodiment. As illustrated in FIG. 6, in the drying container 101, the fluidizing gas supply line 111 is provided for each fluidizing gas supply port 104, and the fluidizing gas supply line 111 is connected with the steam 25 supply line 131 attached with the flowrate adjustment valve 132 and is connected with the non-condensable gas supply line 133 attached with the flowrate adjustment valve 134. Further, in the drying container 101, the gas discharge line 113 is provided for the gas discharge port 105, and is 30 attached with the flowrate adjustment valve 114 and the fan 115. [0095] Then, the control device 125 changes the dew point temperature inside the drying container 101 by Docket No. PMHA-13046-PCT 35 adjusting the pressure inside the drying container 101 through the adjustment of the opening degree of the flowrate adjustment valve 114 based on the detection result of the first temperature detecting sensor 121. That is, 5 when the temperature of the fluid bed S decreases, the control device 125 decreases the pressure inside the drying container 101 by increasing the opening degree of the flowrate adjustment valve 114. Further, the control device 125 changes the dew-point temperature inside the drying 10 container 101 by adjusting the steam concentration inside the drying container 101 through the adjustment of the opening degrees of the flowrate adjustment valves 132 and 134 based on the detection result of the first temperature detecting sensor 121. That is, when the temperature of the 15 fluid bed S decreases, the control device 125 supplies the non-condensable gas by increasing the opening degree of the flowrate adjustment valve 134 and decreases the steam concentration inside the drying container 101 by decreasing the opening degree of the flowrate adjustment valve 132. 20 [0096] In this case, the control device 125 may change the dew-point temperature by adjusting the pressure inside the drying container 101 based on the temperature of the fluid bed S or may adjust the dew-point temperature by adjusting the steam concentration inside the drying 25 container 101. Alternatively, both adjustments may be performed at the same time. [0097] Further, in the above-described respective embodiments, the low-grade coal is used as the wet raw material, but high-grade coal may be employed. Further, 30 the wet raw material is not limited to the coal, and biomass which is used as a renewable biological organic resource may be employed. For example, thinned wood, waste wood, driftwood, grass, waste, mud, a tire, and recycled Docket No. PMHA-13046-PCT 36 fuel (pellet or chip) produced therefrom may be employed. Reference Signs List [0098] 11 coal supply device 12 fluid bed drying apparatus 5 13 coal pulverizer 14 coal gasification furnace 15 char recovery unit 16 gas purification device 17 gas turbine facility 10 18 steam turbine facility 19 generator 20 exhausted heat recovery boiler 101 drying container 102 raw coal input port (wet raw material input unit) 15 103 dry coal discharge port (dry material discharge unit) 104 fluidizing gas supply port (fluidizing gas supply unit) 105 gas discharge port (gas discharge unit) 20 106 heat transfer pipe (heating unit) 111 fluidizing gas supply line 112 flowrate adjustment valve 113 gas discharge line 114 flowrate adjustment valve (dew-point temperature 25 changing device, decompressor) 115 fan 121 first temperature sensor (fluid bed temperature detecting sensor) 122 second temperature sensor 30 123 pressure sensor 125 control device 131 steam supply line 132 flowrate adjustment valve (dew-point temperature Docket No. PMHA-13046-PCT 37 changing device, steam concentration adjusting device) 133 non-condensable gas supply line 134 flowrate adjustment valve (dew-point temperature changing device, steam concentration adjusting device) 5

Claims

1. A fluid bed drying apparatus comprising: a drying container formed in a hollow shape; a wet raw material input unit for inputting a wet raw 5 material to one end side of the drying container; a dry material discharge unit for discharging a dry material obtained by heating and drying the wet raw material from the other end side of the drying container; a fluidizing gas supply unit for supplying a 10 fluidizing gas to a lower portion of the drying container so as to form a fluid bed along with the wet raw material; a gas discharge unit for discharging the fluidizing gas and product steam from the upside of the wet raw material input unit at one end side of the drying 15 container; a heating unit for heating the wet raw material of the fluid bed; a dew-point temperature changing device for changing a dew-point temperature inside the drying container; 20 a fluid bed temperature detecting sensor for detecting the temperature of the fluid bed; and a control device for controlling the dew-point temperature changing device based on a detection result of the fluid bed temperature detecting sensor. 25

2. The fluid bed drying apparatus according to claim 1, wherein the dew-point temperature changing device is a decompressor for changing a pressure inside the drying container, and the control device is suitable for 30 controlling the decompressor based on the temperature of the fluid bed.

3. The fluid bed drying apparatus according to claim 2, Docket No. PMHA-13046-PCT 39 wherein the control device is suitable for controlling the decompressor so that the pressure inside the drying container decreases when the temperature of the fluid bed decreases. 5

4. The fluid bed drying apparatus according to claim 1, wherein the fluidizing gas supply unit is suitable for supplying steam and a non-condensable gas as a fluidizing gas to the lower portion of the drying container, the dew 10 point temperature changing device is a device for controlling the fluidizing gas supply unit so that a steam concentration inside the drying container is adjusted, and the control device is suitable for controlling the steam concentration adjusting device based on the temperature of 15 the fluid bed.

5. The fluid bed drying apparatus according to claim 4, wherein the control device is suitable for controlling the steam concentration adjusting device so that the steam 20 concentration inside the drying container decreases when the temperature of the fluid bed decreases.

6. The fluid bed drying apparatus according to claim 5, wherein the control device is suitable for increasing 25 a non-condensable gas supply amount when the temperature of the fluid bed decreases.

7. The fluid bed drying apparatus according to claim 5, wherein the control device is suitable for decreasing a 30 steam supply amount and increasing a non-condensable gas supply amount when the temperature of the fluid bed decreases so that a fluidizing gas amount is maintained at a constant value.