JP6357969B2 - Drying apparatus and method for drying water-containing material - Google Patents

Description

  The present invention relates to a drying apparatus and a method for drying a water-containing material, such as a high-water content biomass or a low-grade coal such as lignite containing a large amount of water.

  In recent years, it has been required to use a high moisture content biomass or a water content such as a low grade coal such as a high moisture content lignite as a fuel for a boiler.

  When using hydrated products as boiler fuel, the amount of water brought into the furnace is large, so energy is consumed to evaporate the moisture in the hydrated product, and the temperature inside the furnace decreases due to water vapor evaporated from the hydrated products. However, there is a problem that the efficiency of the boiler is lowered.

  For this reason, when using a hydrated product as a fuel for a boiler, a drying device is provided, and the hydrated product is dried while flowing the hydrated product through a fluid medium in the drying device, and dried in advance to remove the moisture hydrated product. Things need to be supplied to the furnace.

  However, the pulverized hydrated product has a particle size distribution in the pulverization step before the hydrated product is put into the drying apparatus, and the particle size varies. Due to the variation in the particle size, a separation occurs in which the hydrated substances with small particle size gather at the upper part and the hydrated substances with large particle diameter gather at the lower part in the drying device, and the particle size collected at the lower part of the drying device. Large hydrated material is in a state where it is difficult to flow.

  In order to flow a hydrated substance having a large particle size, it is necessary to increase the flow rate of the fluidized medium supplied into the drying apparatus. However, increasing the flow rate of the fluidized medium increases energy consumption, There was a problem that scattering of a hydrous material having a small diameter increased.

  In Patent Document 1, the fluidized bed drying apparatus is divided into a first fluid chamber and a second fluid chamber by a partition, and the velocity of fluidized steam in the first fluid chamber is fluidized in the second fluid chamber. While making it larger than the speed of the steam, the coarse particles dried in the first fluidization chamber are selected, extracted by extraction means (not shown), sent to a pulverizer, mixed with wet lignite, pulverized, and again A configuration for supplying to a fluidized bed dryer is disclosed.

JP 2011-214817 A

  In view of such circumstances, the present invention provides a drying apparatus and a method for drying a hydrated product that improve the fluidity of the hydrated product and improve the drying efficiency.

  The present invention includes a drying chamber in which a powdered hydrated product is dried, a hydrated product supplying means for supplying the hydrated product from one end of the drying chamber, and the hydrated product dried from the other end of the drying chamber. Discharge means for discharging small particles, heating means provided in the drying chamber, and a plurality of dividing walls that divide the drying chamber into a plurality of drying compartments and alternately communicate the adjacent drying compartments in the upper part or the lower part Exhaust means for exhausting steam generated by heating from the other end of the drying chamber; fluid medium supply means for ejecting a fluid medium into the drying chamber to liquefy the hydrated material to form a fluidized bed; and Classification means for discharging large particles of hydrated substances, and at least one of the drying compartment on the most upstream side and the drying compartment adjacent to the drying compartment is a classification chamber, and the classification means is provided at the bottom of the classification chamber Related to the drying apparatus.

  Further, according to the present invention, the classifying means includes a cone-shaped collecting portion whose sectional area gradually decreases in the downward direction and whose lower end is opened to the outside, and a plurality of jet nozzles provided over the collecting portion. The fluid medium supply means has a wind box formed at the bottom of the drying chamber, and relates to a drying apparatus in which the classification pipe and the wind box communicate with each other.

  Further, in the present invention, the classifying means has a detecting means for detecting the amount of water of the discharged large particles, and if the amount of water detected by the detecting means is a set value or more, the large particles are removed from the drying chamber. If it is less than a set value, the large particles are combined with the hydrated matter discharged from the discharging means.

  According to the present invention, the fluid medium supply means has a wind box formed at the bottom of the drying chamber, and the window box is divided corresponding to each of the drying compartments, and the flow box is divided into the divided wind boxes. The present invention relates to a drying apparatus to which a medium is supplied.

  Furthermore, the present invention is provided at the bottom of the drying compartment on the upstream side, and a step of supplying a hydrated substance to the drying compartment located upstream of the drying compartment divided into a plurality of drying compartments by a plurality of dividing walls. A step of classifying the large particles of the hydrated product settled by its own weight by the classification unit, a step of detecting the moisture content of the large particles, and an undried hydrated product if the detected moisture content is not less than a set value; The present invention relates to a method for drying a hydrated product comprising a step of merging and a step of merging with a dried hydrated product if the detected water content is less than a set value.

  According to the present invention, the drying chamber in which the powdered hydrated material is dried, the hydrated material supplying means for supplying the hydrated material from one end of the drying chamber, and the dried from the other end of the drying chamber. A plurality of discharge means for discharging small particles of water-containing material, heating means provided in the drying chamber, and a plurality of drying chambers divided into a plurality of drying compartments, and adjacent drying compartments alternately communicating with each other at the upper part or the lower part. A partition wall; exhaust means for exhausting steam generated by heating from the other end of the drying chamber; and fluid medium supply means for ejecting a fluid medium into the drying chamber to liquefy the hydrate and form a fluidized bed. Classifying means for discharging large particles of the hydrated substance, and at least one of the most upstream of the drying compartment and the drying compartment adjacent to the drying compartment is a classification chamber, and the classification means is provided at the bottom of the classification chamber. Since the fluidized bed after classification is It is formed by particles, fluidity is improved, drying efficiency is improved, the supply flow rate of the fluid medium can be reduced, and energy saving in drying the hydrous material can be achieved. it can.

  According to the present invention, the step of supplying a hydrated substance to the drying compartment located upstream of the drying chamber divided into a plurality of drying compartments by a plurality of dividing walls, and the bottom of the drying compartment on the upstream side are provided. A step of classifying the large particles of the hydrated product settled by its own weight by the classification unit, a step of detecting the moisture content of the large particles, and an undried hydrated product if the detected moisture content is equal to or greater than a set value. And the step of merging with the dried hydrated substance if the detected water content is less than the set value, the hydrated substance remaining in the drying chamber becomes only small particles, and the fluidity is As well as improving, it is possible to prevent the merging of undried large particles and the dried hydrated product, the merging of the dried large particles and the hydrated hydrated product, and to improve the drying efficiency. Demonstrate the effect.

It is the schematic which shows the boiler apparatus with which the drying apparatus which concerns on the Example of this invention is applied. It is the schematic which shows the hydrated matter drying system with which the drying apparatus which concerns on the Example of this invention is applied. It is the schematic which shows the drying apparatus which concerns on the 1st Example of this invention. It is a schematic perspective view explaining the inside of the drying apparatus which concerns on the 1st Example of this invention. It is the schematic which shows the drying apparatus which concerns on the 2nd Example of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, referring to FIG. 1, a boiler device 1 to which a hydrated matter drying system according to an embodiment of the present invention is applied will be described.

  In FIG. 1, 2 indicates a furnace of the boiler device 1, and 3 indicates a burner provided on the furnace wall of the furnace 2. The furnace wall of the furnace 2 is provided with a heat transfer tube (not shown) for absorbing radiant heat from the inside of the furnace, and a super heater (superheated steam generation) for heating the generated steam above the furnace 2. 4) is provided.

  In FIG. 1, reference numeral 5 denotes a hydrated material drying system for drying hydrated materials such as biomass and low-grade coal, such as lignite, and when lignite 6 containing moisture is supplied to the hydrated material drying system 5. The hydrated coal drying system 5 dries the lignite 6 and supplies it as the dried lignite 7 to the burner 3.

  By supplying the dry lignite 7 to the burner 3, the dry lignite 7 is burned in the burner 3, and a flame is formed in the furnace 2. The combustion exhaust gas 8 generated by the combustion heats the inside of the furnace 2 and exchanges heat with the super heater 4 to be exhausted through the flue 9.

  Next, referring to FIG. 2, the hydrated material drying system 5 according to the first embodiment of the present invention will be described.

  In FIG. 2, 11 indicates a pulverizer such as a hammer mill that pulverizes the lignite 6 to a predetermined particle size, for example, 2 mm or less, and 12 indicates a drying device. The drying device 12 is pulverized inside. A drying chamber 13 for drying the lignite 6 and cooling it after drying is formed.

  The drying chamber 13 has a heating region 14 formed on the upstream side and a cooling region 15 formed on the downstream side, and the heating region 14 heats the lignite 6 to dry it, and The region 15 cools the dried lignite 7 dried in the heating region 14.

  A lignite supply line 16 for the lignite 6 is connected to an upper portion of the side wall of the drying chamber 13 on the heating region 14 side, and the pulverizer 11 is provided in the middle of the lignite supply line 16, downstream of the pulverizer 11. On the side, a brown coal hopper 17 is provided. The lignite hopper 17, the pulverizer 11, and the lignite supply line 16 constitute a hydrated material supply means.

  An exhaust line 19 as exhaust means is connected to a portion of the top plate 18 of the drying chamber 13 corresponding to the cooling region 15, that is, on the opposite side of the drying chamber 13 to the lignite supply line 16.

  A lignite discharge line 21 is connected to the side wall of the drying chamber 13 on the cooling region 15 side, and the lignite discharge line 21 is connected to the burner 3.

  A heating side wind box 23 is provided below the bottom plate 22 on the heating region 14 side of the drying chamber 13, and a plurality of steam supply nozzles 25 are provided on the bottom plate 22. A fluid medium such as high-temperature bubbling steam 24 is introduced from the steam supply nozzle 25 through a hole (not shown). A cooling side wind box 26 is provided below the bottom plate 22 on the cooling region 15 side, and a plurality of cooling air supply nozzles 28 are provided on the bottom plate 22. A fluid medium such as cooling air 27 is introduced from the cooling air supply nozzle 28 through a hole (not shown).

  Further, a classification portion 29 described later is formed in the vicinity of the side wall (the right side wall in FIG. 2) of the bottom plate 22 on the heating region 14 side. The classifying unit 29 classifies and extracts large particles having a large particle size from the powdery lignite 6 supplied to the drying chamber 13. A large particle classification line 31 is connected to the lower end of the classification unit 29, and the large particle classification line 31 branches into a large particle recovery line 32 and a large particle discharge line 33 on the downstream side. The large particle recovery line 32 is connected to the lignite hopper 17, and the large particle discharge line 33 is connected to the lignite discharge line 21.

  By supplying the bubbling steam 24 and the cooling air 27 to the lignite 6 supplied from the pulverizer 11 via the lignite hopper 17, lignite powder is floated by the bubbling steam 24 and the cooling air 27. Then, a fluidized bed 34 is formed in the drying chamber 13 by the lignite powder liquefied and liquefied.

  The heating region 14 in the fluidized bed 34 is provided with a large number of heat transfer tubes 35 (only one is shown in FIG. 2) as heating means. A superheated steam introduction line 36 is connected to the upstream end of the heat transfer pipe 35, and a part of superheated steam extracted from a turbine of an operating boiler (not shown) is introduced into the superheated steam introduction line 36. Superheated steam flows through the heat pipe 35.

  A drain pipe 37 is connected to the downstream end of the heat transfer pipe 35. The superheated steam flows through the heat transfer pipe 35 and is condensed by exchanging heat with the lignite 6 in the fluidized bed 34 to release latent heat of condensation. The condensed water whose latent condensation heat has been recovered is discharged from the drain pipe 37. The drain pipe 37 is connected to a condenser such as a condenser (not shown), and the condensed water is returned to the boiler.

  The superheated steam introduction line 36 is connected to a bubbling steam introduction line 38 that branches from a middle portion of the superheated steam introduction line 36. The bubbling steam introduction line 38 is connected to the heating side wind box 23, and the remaining superheated steam extracted from the boiler turbine serves as the bubbling steam 24 through the heating side wind box 23 and the steam supply nozzle 25. To be supplied.

  A cooling air introduction line 39 is connected to the cooling side window box 26. The cooling air introduction line 39 is connected to a cooling air supply source (not shown), and the cooling air 27 is supplied to the cooling air supply nozzle 28 via the cooling side window box 26.

  The steam supply nozzle 25, the cooling air supply nozzle 28, the heating side wind box 23, the cooling side window box 26, the bubbling steam introduction line 38, and the cooling air introduction line 39 constitute a fluid medium supply means. The

  Next, the details of the drying device 12 will be described with reference to FIGS. FIG. 4 is a view showing a part of the drying device 12. 3 and 4, the heat transfer tube 35 is shown only on the upper part of the fluidized bed 34 in the heating region 14, but the middle and lower portions of the fluidized bed 34 are also the same. Is provided.

  The lignite hopper 17 stores the lignite 6 pulverized by the pulverizer 11 (see FIG. 2), and the heating region 14 of the drying chamber 13 from the lignite hopper 17 through the lignite supply line 16. The lignite 6 is supplied to the upstream portion (first drying compartment 51 described later). The opening position of the lignite supply line 16 with respect to the drying chamber 13 is located above the opening position of the lignite discharge line 21 with respect to the drying chamber 13. The height difference between the opening position of the lignite supply line 16 and the opening position of the lignite discharge line 21 is appropriately determined according to the fluidity of the lignite 6 liquefied by bubbling and the drying processing capability of the drying device 12. .

  In the drying chamber 13, a plurality of dividing walls provided to divide the drying chamber 13 into a plurality of drying compartments, for example, a first dividing wall 41, a second dividing wall 42, and a third dividing wall from the upstream side. There are six divided walls 43, a fourth divided wall 44, a fifth divided wall 45, and a sixth divided wall 46.

  The first dividing wall 41 to the third dividing wall 43 are located in the heating region 14, and the fifth dividing wall 45 and the sixth dividing wall 46 are located in the cooling region 15. Further, the fourth dividing wall 44 is located at the boundary between the heating region 14 and the cooling region 15, so that the heating region 14 and the cooling region 15 are separated by the fourth dividing wall 44. It has become. In addition, the flow length of the lignite 6 is longer in the heating area 14 than in the cooling area 15.

  The first dividing wall 41, the third dividing wall 43, and the fifth dividing wall 45 each have an upper end protruding above the surface of the fluidized bed 34, and between the lower end and the bottom plate 22 of the drying chamber 13. Are formed with gaps 47, 48, 49 having predetermined intervals, respectively. The second dividing wall 42, the fourth dividing wall 44, and the sixth dividing wall 46 are provided so as to protrude above the bottom plate 22 of the drying chamber 13, and the upper end is lowered by a predetermined distance from the surface of the fluidized bed 34. It is located below. The interval between the gaps 47 to 49 is appropriately selected according to the fluidity of the fluidized bed 34.

  A first drying compartment 51 is formed between the first dividing wall 41 and the side wall of the drying apparatus 12 on the lignite supply line 16 side, and between the first dividing wall 41 and the second dividing wall 42. A second drying compartment 52 is formed, a third drying compartment 53 is formed between the second dividing wall 42 and the third dividing wall 43, and the third dividing wall 43 and the fourth dividing wall 44 A fourth drying compartment 54 is formed between them, a fifth drying compartment 55 is formed between the fourth partition wall 44 and the fifth partition wall 45, and the fifth partition wall 45 and the sixth partition wall 46. A sixth drying compartment 56 is formed between the sixth dividing wall 46 and a side wall of the drying device 12 on the lignite discharge line 21 side.

  The lignite 6 supplied from the lignite supply line 16 is liquefied by bubbling of the bubbling steam 24 and bubbling of the cooling air 27 and is discharged from the lignite discharge line 21 before the first drying. Flows in the compartment 51 to the fourth dry compartment 54 while being turned upside down and dried, and flows in the fifth dry compartment 55 to the seventh dry compartment 57 while being turned upside down and cooled. It is like. By flowing while the first dry compartment 51 to the seventh dry compartment 57 are turned upside down, the length of the flow path becomes long, and sufficient time is provided for drying and cooling.

  The first dry compartment 51 classifies the pulverized lignite 6 supplied from the lignite supply line 16 into large particles having a large particle size and small particles having a small particle size to extract large particles. It functions as a classification room.

  The classification part 29 is formed on the bottom plate 22 of the first drying compartment 51. The classification unit 29 includes, for example, an inverted quadrangular pyramid collection unit 58 whose cross-sectional area gradually decreases downward, and a plurality of classification pipes 59 provided across the upper end of the collection unit 58. Yes. The collecting portion 58 may have any shape as long as it is a cone whose sectional area gradually decreases downward, such as an inverted conical shape.

  The collecting unit 58 has a lower end that opens to the outside of the drying chamber 13 and communicates with the large particle classification line 31. The classification pipe 59 is disposed in a horizontal direction, for example, in parallel with a direction orthogonal to the heat transfer pipe 35, and communicates with the inside of the heating side wind box 23, and the inside of the classification pipe 59 passes through the bubbling steam. 24 is in circulation. In addition, a plurality of outlets (not shown) for ejecting the bubbling steam 24 downward are provided at a lower end of the classification pipe 59 at a predetermined interval. In addition, the space | interval between the said classification pipes 59 which adjoin is about 16 mm, for example, It is a magnitude | size which can pass the large particle | grains of the said lignite 6, for example, this lignite 6 with a particle size of about 2 mm.

  A rotary valve 61, a hopper 62, and a valve 63 are provided in the middle of the large particle classification line 31 in order from the upstream side. The rotary valve 61 is configured to send a large amount of the lignite 6 particles (hereinafter referred to as “large particles”) accumulated in the collecting unit 58 to the downstream side by a predetermined amount. The large particles sent out are temporarily stored. Further, the valve 63 is configured to send the large particles stored in the hopper 62 to a conveyor 64 described later.

  The hopper 62 is provided with a detecting means for detecting the amount of moisture in the large particles stored in the hopper 62, for example, a moisture sensor 65 using near infrared that can detect the amount of moisture without contact. Yes.

  Further, at the downstream end of the large particle classification line 31, the conveyor 64 serving as sorting means and conveying means is provided. The conveyor 64 includes a sorting conveyor 66 that can be driven forward and backward, a forward conveyor 67 that can be driven in the forward direction (conveying leftward in the figure), and a reverse that can be driven backward (conveying rightward in the figure). A conveyor 68 is provided. The sorting conveyor 66, the forward conveyor 67, and the reverse conveyor 68 are covered with an airtight case 69. The forward conveyor 67 conveys the large particles of the lignite 6 distributed by the distribution conveyor 66 to the large particle discharge line 33, and the reverse conveyor 68 transmits the lignite 6 distributed by the distribution conveyor 66. The large particles are conveyed to the large particle recovery line 32.

  The classification unit 29, the large particle classification line 31, the large particle recovery line 32, the large particle discharge line 33, the rotary valve 61, the hopper 62, the valve 63, the conveyor 64, the moisture sensor 65, The case 69 constitutes a classification means.

  Next, the drying of the lignite 6 by the hydrated matter drying system 5 according to the present embodiment will be further described.

  First, the unpulverized brown coal 6 is put into the pulverizer 11 and pulverized by the pulverizer 11 so that the particle diameter becomes 2 mm or less. After the lignite 6 pulverized by the pulverizer 11 is stored in the lignite hopper 17, the lignite 6 is charged into the drying device 12 through the lignite supply line 16. At this time, the lignite 6 has a particle size distribution of about 10 μm to 2 mm.

  The lignite 6 supplied to the drying device 12 is accumulated in the first drying compartment 51, and the bubbling steam 24 is supplied to the accumulated lignite 6 from an outlet (not shown) of the classification pipe 59. Thus, the fluidized bed 34 of the lignite 6 liquefied and having fluidity is formed.

  At this time, the flow rate of the bubbling steam 24 ejected from the ejection port is a flow rate for fluidizing only the lignite 6 having a small particle diameter of less than 1 mm. Accordingly, among the lignite 6, large particles of the lignite 6 having a particle diameter of 1 mm or more settle in the first dry compartment 51 without being fluidized. Further, since the jet port opens at the lower end of the classification pipe 59, the lignite 6 is prevented from flowing into the classification pipe 59.

  The large particles that have settled in the first drying compartment 51 pass between the classification pipes 59, 59 and accumulate in the collection unit 58. The large particles deposited on the collection unit 58 further descend along the slope of the collection unit 58 and are discharged to the large particle classification line 31 through the rotary valve 61.

  The large particles discharged to the large particle classification line 31 are sent to the hopper 62 by a predetermined amount while the airtight state of the classification unit 29 is maintained by the rotation of the rotary valve 61. It is stored in. The large particles stored in the hopper 62 are detected by the moisture sensor 65 to detect the amount of moisture contained therein, and the driving direction of the sorting conveyor 66 is determined depending on whether the amount of contained moisture is equal to or greater than a set value. . The set value of the water content of the large particles is set in the range of 10% to 30%, more preferably 20%.

  For example, if the water content of the large particles is 20% or more, the sorting conveyor 66 is driven so as to convey the large particles to one end side (the right side with respect to the paper surface in FIG. 3). If the moisture content is less than 20%, the sorting conveyor 66 is driven so as to convey the large particles to the other end side (left side with respect to the paper surface in FIG. 3).

  When the sorting conveyor 66 is driven based on the detection result of the moisture sensor 65, the valve 63 is opened, and the large particles stored in the hopper 62 are supplied onto the sorting conveyor 66. . After supplying the large particles in the hopper 62 onto the sorting conveyor 66, the valve 63 is closed.

  The large particles supplied onto the sorting conveyor 66 are transported to one end by the sorting conveyor 66 and the reverse conveyor 68 if the detected water content is equal to or greater than a set value, and the large particle recovery line It is circulated to the lignite hopper 17 through 32. Further, if the detected water content is less than a set value, the large particles are transported to the other end side by the sorting conveyor 66 and the forward conveyor 67, and the large particles are discharged via the large particle discharge line 33. It is sent to the brown coal discharge line 21.

  The moisture content of the large particles stored in the hopper 62 is continuously detected, and the driving direction of the sorting conveyor 66 is determined based on the detection result at each time. The large particles are conveyed to the large particle recovery line 32 or the large particle discharge line 33 by the rolling conveyor 67 and the reverse conveyor 68.

  The classification process described above is repeated until the drying process of the lignite 6 is completed.

  In parallel with the supply of the lignite 6 from the lignite supply line 16, superheated steam is introduced into the superheated steam introduction line 36, and the superheated steam flows through the heat transfer pipe 35.

  The fluidized bed 34 flows downward in the first drying compartment 51, the large particles are removed by the classifying unit 29, and the fluidized bed 34, which contains only small particles, enters the gap 47. It flows out and flows into the second drying compartment 52. At this time, since the introduced lignite 6 contains a large amount of water, the lignite 6 flows down by its own weight. The lignite 6 stays in the first drying compartment 51, but the lower lignite 6 is extruded from the gap 47 into the second drying compartment 52 by the pressure from the upper part and flows. The lignite 6 is in contact with the heat transfer pipe 35 in the process of flowing from the first dry compartment 51 to the second dry compartment 52, and the heat of the superheated steam flowing through the heat transfer pipe 35 and the bubbling steam 24. Heated by exchange and dried.

  The size of the gap 47 is set according to the fluidity of the fluidized bed 34 so that the lignite 6 does not move over the first dividing wall 41 and move to the second drying compartment 52. Further, the amount of the lignite 6 input from the lignite hopper 17 and the amount of the large particles discharged by the classification unit 29 are set so as not to get over the first dividing wall 41 and move to the second drying compartment 52. Adjusted.

  The lignite 6 that has flowed into the second drying compartment 52 is reversed in the second drying compartment 52 and flows upward from below, and passes over the second dividing wall 42 to the third drying compartment 53. Flows in the third drying compartment 53 and flows downward from above, flows through the gap 48 and flows into the fourth drying compartment 54, and inverts in the fourth drying compartment 54. It flows from the bottom to the top.

  At this time, the lignite 6 is dried by heat exchange in the first drying compartment 51, and the large particles are removed from the lignite 6 by classification by the classification unit 29, whereby the fluidity of the fluidized bed 34 is increased. Further, the lignite 6 smoothly flows to the third dry compartment 53 and the fourth dry compartment 54 without backflow by the pressure from the first dry compartment 51 side.

  Also in the second drying compartment 52 to the fourth drying compartment 54, the brown coal 6 is heated by the superheated steam and the bubbling steam 24 that circulates in the heat transfer pipe 35 in the process of flowing upside down. Dried.

  The dried lignite 7 dried in the first drying compartment 51 to the fourth drying compartment 54 passes over the fourth dividing wall 44 and flows to the fifth drying compartment 55 in the cooling region 15. The dry lignite 7 that has flowed into the fifth dry compartment 55 is reversed in the fifth dry compartment 55 and flows downward from above, flows through the gap 49, and flows into the sixth dry compartment 56. To do. The dry lignite 7 is reversed in the sixth dry compartment 56 and flows upward from below, flows over the sixth dividing wall 46 and flows into the seventh dry compartment 57, and the lignite discharge line 21. More discharged.

  The dry lignite 7 is cooled by the cooling air 27 supplied from the cooling air supply nozzle 28 in the process of flowing while inverting the fifth dry compartment 55 to the seventh dry compartment 57. Further, steam and cooling air 70 generated in the process in which the lignite 6 and the dried lignite 7 are dried and cooled by flowing through the first dry compartment 51 to the seventh dry compartment 57 are connected to the exhaust line 19. Exhausted to the outside.

  The superheated steam flowing through the heat transfer pipe 35 is subjected to heat exchange with the lignite 6 in the fluidized bed 34 in the process of flowing through the heat transfer pipe 35. Through heat exchange with the lignite 6, the condensation latent heat of the superheated steam is recovered and phase-changed to become condensed water, which is sent to a condenser such as a condenser (not shown) through the drain pipe 37.

  The cooled dry lignite 7 discharged from the drying chamber 13 is sent to the burner 3, and the dry lignite 7 is burned by the burner 3.

  As described above, in the first embodiment of the present invention, the drying compartment on the most upstream side of the drying chamber 13 is the first drying compartment 51, and the classification unit 29 is provided in the first drying compartment 51, The classification unit 29 extracts large particles having a predetermined particle size or more from the lignite 6 and discharges them to the outside of the drying chamber 13. Therefore, the fluidized bed 34 that flows in the drying chamber 13 is formed only by small particles having a particle diameter smaller than a predetermined particle size, and thus improves the fluidity of the fluidized bed 34 and improves the drying efficiency. it can.

  Further, the fluidized bed 34 on the downstream side of the first drying compartment 51 is formed of small particles of the lignite 6 so as to reduce the supply flow rate of the fluidized medium for causing the fluidized bed 34 to flow. Energy saving in the drying process of the lignite 6 can be achieved. Moreover, the small particle scattering can be reduced by reducing the supply flow rate of the fluid medium.

  Further, the classification unit 29 is provided at the bottom of the first drying compartment 51, and the classification unit 29 is provided across the collection unit 58 having an inverted quadrangular pyramid shape and the collection unit 58 to flow only the small particles. The classifying pipe 59 that ejects the bubbling vapor 24 at a flow rate to cause the large particle to settle by its own weight and deposit along the slope of the collecting unit 58, and a mechanism for classification This eliminates the need for a unit and simplifies the apparatus configuration.

  In addition, the moisture content of the large particles discharged through the classification unit 29 is detected by the moisture sensor 65, and the driving direction of the conveyor 64 is changed based on the detection result. Depending on the amount, the lignite hopper 17 and the lignite discharge line 21 are fed. Accordingly, it is possible to prevent the undried lignite 6 from being fed to the lignite discharge line 21 and to prevent the dried lignite 7 from being supplied to the drying chamber 13 again. The drying efficiency of can be improved.

  Further, in the first embodiment, the fourth dividing wall 44 partitions the drying chamber 13 into the heating region 14 for heating and drying the lignite 6 and the cooling region 15 for cooling the dry lignite 7. In addition, since the drying chamber 13 can both dry the lignite 6 and cool the dried lignite 7, there is no need to provide a separate cooling mechanism for cooling the dried lignite 7, and the apparatus configuration is simple. Thus, the manufacturing cost can be reduced.

  Also, the heating region 14 is divided into the first drying compartment 51, the four partition walls, the first partition wall 41, the second partition wall 42, the third partition wall 43, and the fourth partition wall 44. Divided into four dry compartments, a second dry compartment 52, a third dry compartment 53, and a fourth dry compartment 54, and each division so that the lignite 6 flows while turning upside down between the dry compartments 51-54. Walls 41 to 44 are arranged. Therefore, the distance over which the lignite 6 flows is increased, the time for heating by the heat transfer pipe 35 and the bubbling steam 24 can be increased, the drying device 12 can be downsized, and a large amount of the lignite 6 can be obtained. It can be dried efficiently.

  Also, the cooling region 15 is divided into the fifth drying compartment 55, the sixth drying compartment 56, the three partition walls of the fourth partition wall 44, the fifth partition wall 45, and the sixth partition wall 46. Each of the dividing walls 44 to 46 is arranged so that the dry lignite 7 is divided into three drying compartments of the seventh drying compartment 57 and flows while the dry lignite 7 is inverted between the respective drying compartments 55 to 57. Therefore, the distance that the dried lignite 7 flows, that is, the time for cooling by the cooling air 27 can be increased, and a large amount of the dried lignite 7 can be efficiently cooled.

  Further, the upper ends of the first dividing wall 41, the third dividing wall 43, and the fifth dividing wall 45 are protruded upward from the surface of the fluidized bed 34, and the first dividing wall 41, the third dividing wall are projected. 43, the gaps 47 to 49 are formed between the lower end of the fifth dividing wall 45 and the bottom plate 22, respectively, and the second dividing wall 42, the fourth dividing wall 44, and the sixth dividing wall 46 are formed. Since it is provided so as to protrude upward from the bottom plate 22 and no gap is formed between the bottom plate 22, the lignite 6 and the dry lignite 7 can be reliably reversed upward, It is possible to prevent the lignite 6 and the dried lignite 7 from staying in the drying chamber 13.

  Further, since the fourth dividing wall 44 is provided at the boundary between the heating region 14 and the cooling region 15, the bubbling vapor 24 can be prevented from entering the cooling region 15 and the cooling air 27 can be prevented. Can be prevented from being mixed into the heating region 14, and the heating efficiency of the lignite 6 and the cooling efficiency of the dry lignite 7 can be prevented from decreasing.

  Next, a second embodiment of the present invention will be described with reference to FIG. 5 that are the same as those in FIG. 3 are given the same reference numerals, and descriptions thereof are omitted.

  In the second embodiment, the heating side wind box 23 (see FIG. 3) and the cooling side window box 26 (see FIG. 3) are divided so as to correspond to the respective drying compartments 51 to 57. That is, the first wind box 71 corresponding to the first drying compartment 51, the second wind box 72 corresponding to the second drying compartment 52, the third wind box 73 corresponding to the third drying compartment 53, and the fourth drying compartment 54. A corresponding fourth wind box 74, a fifth wind box 75 corresponding to the fifth drying compartment 55, a sixth wind box 76 corresponding to the sixth drying compartment 56, and a seventh wind box 77 corresponding to the seventh drying compartment 57 are provided. Each is provided.

  The bubbling steam introduction line 38 is connected to the first wind box 71 to the fourth wind box 74, and the bubbling steam introduction line 38 has a first adjustment valve 79 to a fourth adjustment valve 82 corresponding to each wind box. Is provided.

  The cooling air introduction line 39 is connected to the fifth window box 75 to the seventh window box 77, respectively. The cooling air introduction line 39 has fifth adjustment valves 83 to seventh adjustments corresponding to the respective wind boxes. A valve 85 is provided.

  The bubbling steam 24 is adjusted in flow rate to the first adjustment valve 79 and supplied to the first window box 71, adjusted in flow rate to the second adjustment valve 80 and supplied to the second window box 72, and the third adjustment valve 79. The flow rate is adjusted by the adjustment valve 81 and supplied to the third window box 73, and the flow rate is adjusted by the fourth adjustment valve 82 and supplied to the fourth window box 74.

  The cooling air 27 is adjusted in flow rate to the fifth adjustment valve 83 and supplied to the fifth window box 75, and the flow rate is adjusted in the sixth adjustment valve 84 and supplied to the sixth window box 76. The flow rate is adjusted by the seventh adjustment valve 85 and supplied to the seventh window box 77.

  In the second embodiment, the flow rate of the flow rate medium supplied to each of the drying compartments 51 to 57 can be individually adjusted. Therefore, since the supply flow rate of the bubbling steam 24 and the cooling air 27 can be adjusted in accordance with the flow state of the fluidized bed 34, such as the drying condition of the brown coal 6, the fluidity of the fluidized bed 34 can be further improved. The drying efficiency of the lignite 6 can be improved.

  In the first embodiment and the second embodiment, the first drying compartment 51 is a classification chamber, and classification means is provided at the bottom of the first drying compartment 51. The second drying compartment 52 may be provided. In addition, it goes without saying that the classification means may be provided in both the first drying compartment 51 and the second drying compartment 52 so that the particle size of the lignite 6 forming the fluidized bed 34 becomes smaller. Nor.

DESCRIPTION OF SYMBOLS 1 Boiler apparatus 5 Water content drying system 6 Brown coal 12 Drying apparatus 13 Drying room 14 Heating area 15 Cooling area 17 Brown coal hopper 21 Brown coal discharge line 23 Heating side wind box 24 Bubbling steam 26 Cooling side wind box 27 Cooling air 29 Classifying part 31 Large Particle classification line 32 Large particle recovery line 33 Large particle discharge line 34 Fluidized bed 35 Heat transfer tube 51 First drying compartment 58 Collection section 59 Classification pipe 61 Rotary valve 64 Conveyor 65 Moisture sensor 71-77 First to seventh wind boxes 79- 85 1st to 7th adjustment valve

Claims (4)

A drying chamber in which the powdered water-containing material is dried, a water-containing material supply means for supplying the water-containing material from one end of the drying chamber, and small particles of the water-containing material dried from the other end of the drying chamber. A discharge means for discharging, a heating means provided in the drying chamber, a plurality of dividing walls that divide the drying chamber into a plurality of drying compartments, and alternately communicate the adjacent drying compartments in the upper part or the lower part, and by heating Exhaust means for exhausting the generated steam from the other end of the drying chamber, fluidized medium supply means for ejecting a fluidized medium into the drying chamber to liquefy the hydrated material to form a fluidized bed, Classification means for discharging particles, at least one of the most upstream drying compartment and the drying compartment adjacent to the drying compartment is a classification chamber, and the classification means is provided at the bottom of the classification chamber , and the classification Means detect the water content of the discharged large particles If the amount of water detected by the detection means is greater than or equal to a set value, the large particles are circulated to the drying chamber, and if less than the set value, the large particles are discharged from the discharge means. Further , the drying apparatus is characterized by being combined with the hydrated material .   The classifying means comprises: a cone-shaped collecting part whose sectional area gradually decreases downward and whose lower end opens to the outside; and a plurality of classifying pipes provided on the collecting part and formed with a plurality of jet outlets The drying apparatus according to claim 1, wherein the fluid medium supply means includes a wind box formed at a bottom portion of the drying chamber, and the classification pipe and the wind box communicate with each other. The fluid medium supply means has a window box formed at the bottom of the drying chamber, the window box is divided corresponding to each drying compartment, and the fluid medium is supplied to each of the divided window boxes. The drying apparatus according to claim 1 or 2 .   A step of supplying a hydrated substance to the drying compartment located upstream of the drying compartment divided into a plurality of drying compartments by a plurality of dividing walls, and sedimentation by its own weight by a classification section provided at the bottom of the drying compartment on the upstream side A step of classifying the large particles of the hydrated product, a step of detecting the moisture content of the large particles, a step of merging with an undried hydrated product if the detected moisture content is equal to or greater than a set value, and a detection And a step of merging with the dried hydrated product if the water content is less than the set value.

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