JP6520541B2 - Drying system - Google Patents

Description

  The present invention relates to a drying system for drying a material to be dried such as brown coal.

  Coal has a harvestable age of around 150 years, which is more than three times that of petroleum, and compared to petroleum, there is no uneven distribution of reserves, so it is a natural resource that can be stably supplied over a long period of time As expected. Coal is classified into peat, lignite, lignite, subbituminous coal, bituminous coal, semianthracite and anthracite in ascending order of carbon content; peat, lignite, lignite, subbituminous coal (hereinafter referred to as hydrous coal) is bituminous coal, The water content (water content) is higher than that of anthracite or anthracite (hereinafter referred to as anthracite).

  Among the water-containing coals, lignite is said to occupy half of the world's coal reserves, so effective use of lignite is being considered. However, as described above, water-containing coal such as lignite has a high water content as compared with anthracite etc., so the calorific value per unit weight is low and energy efficiency as fuel for transportation cost is low.

  Therefore, by supplying high temperature fluidization gas from the bottom of the storage tank containing water-containing coal, a fluid bed of water-containing coal is formed in the storage tank, and heat of the fluidization gas is added to the water-containing coal to obtain water-containing coal. Techniques for drying are being developed (eg, Patent Documents 1 and 2).

JP, 2013-44461, A Japanese Patent Publication No. 63-18636

  In the fluidized bed, the fluidity of the hydrous coal is biased, and the lower layer of the fluidized bed has lower fluidity of the hydrous coal than the upper layer. Therefore, in the lower layer of the fluidized bed, the contact probability between the water-containing coal and the fluidizing gas is low, and the drying efficiency is lower than in the upper layer.

  On the other hand, water-containing coal has variations in particle size and mass density, and particles with relatively large particle sizes and particles with relatively large mass density (hereinafter referred to as "heavy particles") have relatively large particle sizes. It is difficult to dry because the water content is larger than the particles having a relatively small particle size or particles having a relatively small mass density (hereinafter referred to as "light particles").

  As described above, when water-containing coal having variation in particle size and mass density is introduced into the storage tank, heavy particles that are difficult to dry are in the lower layer of the fluid bed with low drying efficiency, and light particles that are easy to dry are fluid with high drying efficiency. It tends to stay in the upper layer of the bed. Therefore, the deviation of the drying time becomes large between the heavy particles and the light particles, and the drying time of the whole of the water-containing coal is prolonged as compared with the case where there is no deviation.

  Further, as described above, since the light particles tend to stay in the upper layer of the highly fluid bed, the possibility of scattering from the fluid bed becomes high, and the fluid is discharged to the outside from the discharge port for discharging the fluidizing gas. There is a risk of

  Then, in view of such a subject, the present invention can dry efficiently things to be dried, such as brown coal which have variation in particle size and mass density, and can control scattering of a thing to be dried. It is intended to provide a drying system.

  In order to solve the above-mentioned subject, a drying system of the present invention forms a fluid bed by making a thing to be dried flow by fluidization gas, and it is the 1st drying furnace which dries a thing to be dried by fluidization gas, A dried material introduced by the first drying furnace is introduced, and the introduced dried material is fluidized by a fluidizing gas to form a fluidized bed, and the drying material is further dried by the fluidizing gas. 2) A drying furnace, a first moving means for moving a material to be dried under the fluidized bed in the first drying furnace to the upper layer of the fluidized bed in the second drying furnace, and a material to be dried over the fluidized bed in the first drying furnace And a second moving means for moving the lower layer to the lower layer of the fluidized bed in the second drying furnace.

  In addition, the first drying furnace has a lower outlet through which the lower-layer material to be dried is delivered, and an upper outlet provided above the lower outlet, and the upper-layer matter to be dried is discharged. The apparatus has an upper inlet into which the material to be dried delivered from the lower outlet is introduced, and a lower inlet provided below the upper inlet and into which the material to be dried delivered from the upper outlet is introduced; The moving means includes a first connecting pipe connecting the lower outlet of the first drying furnace and the upper inlet of the second drying furnace, and the second moving means includes the upper outlet of the first drying furnace, and 2) A second connecting pipe is provided to connect with the lower inlet of the drying oven, and the first drying oven and the second drying oven are such that the upper surface of the fluidized bed in the first drying oven is the same as that of the fluidized bed in the second drying oven The upper surface, the upper inlet of the second drying oven, and the lower inlet of the second drying oven shall be configured to be above. It may be.

  In the first and second drying ovens, the lower outlet of the first drying oven is disposed above the upper inlet of the second drying oven, and the upper outlet of the first drying oven is the lower portion of the second drying oven It may be configured to be disposed above the inlet.

  ADVANTAGE OF THE INVENTION According to this invention, to-be-dried things, such as a brown coal which have a dispersion | variation in a particle size or mass density, can be dried efficiently, and it becomes possible to suppress scattering of a to-be-dried material.

It is a figure for demonstrating a drying system. It is a conceptual diagram for demonstrating the behavior of the lignite in a 1st drying furnace. It is a conceptual diagram for demonstrating the behavior of the brown coal in a 2nd drying furnace.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values and the like shown in this embodiment are merely examples for facilitating the understanding of the invention, and do not limit the present invention unless otherwise specified. In the specification and the drawings, elements having substantially the same functions and configurations will be denoted by the same reference numerals to omit repeated description, and elements not directly related to the present invention will not be illustrated. Do.

  FIG. 1 is a diagram for explaining the drying system 100. As shown in FIG. In FIG. 1, the flow of the material to be dried is indicated by the black solid arrows, the flow of the fluidizing gas is indicated by the outlined arrows, and the flow of the heat medium is indicated by the broken arrows. Further, in the present embodiment, as a material to be dried, lignite is taken as an example and described.

  As shown in FIG. 1, the drying system 100 is configured to include a first drying furnace 110, a first separation device 120, a second drying furnace 210, and a second separation device 220. The first drying furnace 110 is configured to include a first housing portion 112, an air box 114, and a heat transfer tube 116.

  The first accommodation portion 112 is provided with an introduction port 112a, and brown coal is introduced into the first accommodation portion 112 through the introduction port 112a. In addition, a wind box 114 is provided below the first housing portion 112, and when the drying system 100 is operated, the inside of the first housing portion 112 from the bottom surface of the first housing portion 112 through the wind box 114. The fluidization gas (e.g., water vapor) is supplied to the

  Specifically, the upper portion of the wind box 114 also functions as a bottom surface of the first accommodation portion 112 and is formed of a dispersive plate 114 a that can be ventilated. The dispersion plate 114a is formed of, for example, a plate provided with a plurality of openings having a diameter smaller than the particle diameter of brown coal, or a plate provided with a nozzle provided with an opening having a diameter smaller than the particle diameter of brown coal. . The air box 114 supplies the fluidizing gas (eg, water vapor) into the first container 112 through the opening of the dispersion plate 114 a. The fluidizing gas thus supplied to the first containing portion 112 causes the lignite to flow in the first containing portion 112 to form a fluidized bed, and the high temperature (for example, about 110 ° C.) fluidizing gas with the lignite. Dry the lignite by contacting.

  In addition, a heat transfer pipe 116 is provided in the first accommodation portion 112, and a heat transfer medium (for example, water vapor) is supplied to the heat transfer pipe 116 from a supply source (not shown). With the configuration including the heat transfer tube 116, heat exchange is performed between the heat medium and the fluidizing gas in the first housing portion 112, and the fluidizing gas moving upward can be further heated. This further promotes the drying of the brown coal by the fluidizing gas.

  In addition, the first separation device 120 is connected to the first storage unit 112 via a gas discharge port 112 b provided at the upper part and a gas discharge pipe 112 c connected to the gas discharge port 112 b. The first separation device 120 is a solid-gas separation device (cyclone), and is connected to the first accommodation portion 112 and to the second connection pipe 260 described later via the downfalling pipe 122. In the first separation device 120, particulate brown coal scattered in the first storage unit 112 together with the gas in the first storage unit 112 (fluidization gas and steam evaporated from brown coal) through the gas discharge pipe 112c. Is introduced. Then, the brown coal recovered (separated) from the gas by the first separation device 120 is introduced into the second connection pipe 260 via the downfalling pipe 122.

  As described above, in the first drying furnace 110, the lignite is dried by the fluidizing gas, but the lignite introduced into the first drying furnace 110 has variations in particle diameter and mass density, and It is said that the whole brown coal can not be efficiently dried because heavy particles with relatively large particle size and mass density and light particles with relatively small particle size and mass density differ in ease of drying (the difficulty of drying). There's a problem.

  FIG. 2 is a conceptual diagram for explaining the behavior of brown coal in the first drying furnace 110. As shown in FIG. In FIG. 2, heavy particles are shown by white circles and light particles are shown by black circles for easy understanding. As described above, the fluidizing gas is supplied from the bottom of the first container 112 and causes the lignite to flow in the process of rising. The fluidizing gas has a small bubble diameter in the lower layer of the fluidized bed, but in the ascending process, the bubbles are associated with each other to increase the diameter. For this reason, the fluidity of the lignite by the fluidizing gas is higher in the upper layer than in the lower layer. Accordingly, it can be said that the upper layer of the fluidized bed has larger movement of the particles of the lignite than the lower layer, and therefore, the mass transfer between the particles of the lignite and the fluidizing gas is large and the drying efficiency is high.

  As shown in FIG. 2, of the lignite introduced into the first drying furnace 110, heavy particles move to the lower layer of the fluidized bed, as indicated by the solid arrows in FIG. On the other hand, the light particles hardly move to the lower layer of the fluidized bed and stay in the upper layer. That is, heavy particles that are difficult to dry stay in the lower layer with low drying efficiency, and light particles that are easy to dry stay in the upper layer with high drying efficiency. Then, the deviation of the drying time becomes large between the heavy particles and the light particles, and the drying time of the entire brown coal is prolonged as compared with the case where there is no deviation.

  In addition, since the upper layer of the fluidized bed has high fluidity, lignite may scatter from the upper layer of the fluidized bed. The first separating device 120 is provided because the scattered brown coal is discharged to the outside through the gas discharge port 112 b. However, in the first drying furnace 110, since the light particles that are more likely to scatter than the heavy particles stay in the upper layer of the fluidized bed, as shown by the broken arrows in FIG. As a result, the load on the first separation device 120 for recovering the scattered brown coal increases.

  Therefore, in the drying system 100 according to the present embodiment, the brown coal dried in the first drying furnace 110 is classified, and the introduced position of the classified brown coal into the second drying furnace 210 is devised, whereby the drying in the second drying furnace 210 is performed. It enables shortening of time and suppression of scattering of light particles.

  Referring back to FIG. 1, the second drying furnace 210 is configured to include a second housing portion 212, an air box 114, and a heat transfer tube 116. The air box 114 and the heat transfer tube 116 have substantially the same configuration as the air box 114 and the heat transfer tube 116 of the first drying furnace 110 described above, and thus the description thereof will be omitted.

  Although mentioned later in detail, the brown coal dried by the 1st drying furnace 110 is introduced into the 2nd seat part 212. As shown in FIG. A wind box 114 is provided below the second storage unit 212 in the same manner as the first storage unit 112 of the first drying furnace 110. When the drying system 100 is operated, the second A fluidizing gas (for example, water vapor) is supplied from the bottom of the storage portion 212 into the second storage portion 212. Then, the fluidizing gas supplied to the second containing portion 212 causes the lignite to flow in the second containing portion 212 to form a fluidized bed, and at the same time, the heat of the fluidizing gas is transferred to the lignite to generate the lignite. Heat to dry.

  In addition, a second separation device 220 is connected to the second accommodation portion 212 via a gas discharge port 212a provided at the upper part and a gas discharge pipe 212b connected to the gas discharge port 212a. The second separation device 220 is a solid-gas separation device (cyclone), and is connected to the second accommodation portion 212 and to the pipe 230 a connected to the outlet 212 e via the downfalling pipe 222. In the second separator 220, lignite (light particles) scattered in the second container 212 together with the gas in the second container 212 (fluidizing gas and steam evaporated from brown coal) via the gas discharge pipe 212b Is introduced. Then, the brown coal recovered from the gas by the second separation device 220 is introduced into the pipe 230 a through the downfalling pipe 222 and is delivered to the outside.

  Here, the movement (introduction) of the brown coal from the first storage portion 112 of the first drying furnace 110 to the second storage portion 212 of the second drying furnace 210 will be described in the first storage portion 112 of the first drying furnace 110. The lower outlet 112d is provided, and the upper outlet 112e is provided vertically above the lower outlet 112d. Further, an upper inlet 212 c is provided in the second accommodation portion 212 of the second drying furnace 210, and a lower inlet 212 d is provided vertically below the upper inlet 212 c.

  Furthermore, in the first drying furnace 110 and the second drying furnace 210, the upper surface U1 of the fluidized bed in the first drying furnace 110 is the upper surface U2 of the fluidized bed in the second drying furnace 210, and the upper inlet 212c of the second accommodation portion 212, And, it is configured to be above the lower inlet 212d. In the first drying furnace 110 and the second drying furnace 210, the lower outlet 112d of the first drying furnace 110 is disposed above the upper inlet 212c of the second drying furnace 210, and the upper outlet 112e of the first drying furnace 110 Are disposed above the lower inlet 212 d of the second drying furnace 210.

  Then, in the drying system 100, a first connection pipe 250 (first moving means) connecting the lower outlet 112d of the first drying furnace 110 and the upper inlet 212c of the second drying furnace 210, and the first drying furnace 110 A second connection pipe 260 (second moving means) connecting the upper outlet 112e of the second drying furnace 210 and the lower inlet 212d of the second drying furnace 210 is provided.

  Therefore, when lignite is continuously introduced into the first storage unit 112 through the inlet 112 a, the lignite is dried in the first drying furnace 110 and among the lignite dried in the first drying furnace 110, Lignite (heavy particles) in the lower layer of the fluidized bed is delivered from the lower outlet 112d. Then, after the lower layer lignite passes through the first connection pipe 250 by its own weight, it is introduced into the second accommodation portion 212 from the upper inlet 212 c of the second drying furnace 210, and the upper layer of the fluidized bed in the second drying furnace 210 Moved to On the other hand, among the lignite dried in the first drying furnace 110, the lignite in the upper layer of the fluidized bed (light particles) is delivered from the upper outlet 112e. Then, after the upper layer lignite passes through the second connection pipe 260 by its own weight, it is introduced from the lower inlet 212 d of the second drying furnace 210 into the second accommodation portion 212, and the lower layer of the fluidized bed in the second drying furnace 210 Moved to Then, in the second drying furnace 210, heavy particles are introduced to the upper layer of the fluidized bed, and light particles are introduced to the lower layer of the fluidized bed.

  FIG. 3 is a conceptual diagram for explaining the behavior of brown coal in the second drying furnace 210. As shown in FIG. In FIG. 3, heavy particles are shown by white circles and light particles are shown by black circles for easy understanding. As shown in FIG. 3, heavy particles are introduced into the upper layer of the fluidized bed in the second drying furnace 210 through the upper inlet 212c, and light particles are introduced into the lower layer of the fluidized bed through the lower inlet 212d. Then, as shown by the arrows in FIG. 3, the light particles introduced from the lower inlet 212d have a mass density (specific gravity) smaller than that of the heavy particles, and hence the fluidized bed is in the horizontal direction (horizontal direction in FIG. 3). While moving, ascend upward. On the other hand, heavy particles introduced from the upper inlet 212c settle downward while moving in the horizontal direction in the fluidized bed, as shown by the arrows in FIG. At this time, the rising of the light particles decelerates the sedimentation of the heavy particles, and the sedimentation of the heavy particles decelerates the rising of the light particles.

  Thereby, the residence time of heavy particles in the upper layer having high drying efficiency can be taken relatively long, and the total residence time of heavy particles (residence time in the second storage portion 212) compared to the first drying furnace 110 It is possible to increase the ratio of residence time in the upper layer in Thereby, the drying time of heavy particles can be shortened in the second drying furnace 210 as compared to the first drying furnace 110. Therefore, the deviation of the drying time between heavy particles and light particles can be reduced, and the drying time of the entire lignite can be shortened.

  In addition, the residence time of the light particles in the upper layer having high fluidity can be shortened, and in the upper layer in the total residence time of the light particles (residence time in the second accommodation portion 212) as compared with the first drying furnace 110. It is possible to lower the ratio of residence time of Thereby, scattering of light particles from the surface of the fluidized bed can be suppressed, and the load on the second separation device 220 can be reduced as compared to the first separation device 120.

  Thus, the brown coal dried in the second drying furnace 210 is delivered to the outside through the outlets 212 e and 212 f provided in the second accommodation portion 212 and the pipes 230 a and 230 b.

  Further, in the present embodiment, the valve 270 (rotation valve) is provided in the first connection pipe 250 and the pipe 230b. Thereby, it becomes possible to adjust appropriately the flow rate of the brown coal sent out from the 1st seat part 112 to the 2nd seat part 212.

  As described above, according to the drying system 100 according to the present embodiment, the lignite in the lower layer of the fluidized bed in the first drying furnace 110 is moved to the upper layer of the fluidized bed in the second drying furnace 210, and the first drying furnace By moving the brown coal in the upper layer of the fluidized bed in 110 to the lower layer of the fluidized bed in the second drying furnace 210, it is possible to efficiently dry the brown coal having variations in particle size and mass density, and scattering of brown coal. Can be suppressed. Thereby, the transportation cost of brown coal can be reduced and energy efficiency can be improved.

  Although the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to such embodiments. It is obvious that those skilled in the art can conceive of various changes or modifications within the scope of the claims, and it is naturally understood that they are also within the technical scope of the present invention. Be done.

  For example, in the above embodiment, lignite has been described as an example of the material to be dried by the drying system 100. However, it goes without saying that the drying system 100 can dry materials other than brown coal.

  In the above embodiment, the first drying oven 110 and the second drying oven 210 are arranged such that the lower outlet 112 d of the first drying oven 110 is located above the upper inlet 212 c of the second drying oven 210. The upper outlet 112e of the second drying furnace 210 is disposed above the lower inlet 212d of the second drying furnace 210. However, the upper surface U1 of the fluidized bed in the first drying furnace 110 is higher than the upper surface U2 of the fluidized bed in the second drying furnace 210, the upper inlet 212c of the second drying furnace 210, and the lower inlet 212d of the second drying furnace 210. There is no limitation on the positional relationship between the lower outlet 112 d and the upper inlet 212 c and the positional relationship between the upper outlet 112 e and the lower inlet 212 d as long as it is configured to be

  In the above embodiment, the first drying furnace 110 and the second drying furnace 210, the upper surface U1 of the fluidized bed in the first drying furnace 110, the upper surface U2 of the fluidized bed in the second drying furnace 210, the second drying furnace 210 And the upper moving inlet of the second drying furnace 210 and the upper moving inlet of the second drying furnace 210, and the first moving means is the first connecting pipe 250, and the second moving means is the second connecting pipe 260. An example of the configuration has been described. However, the first moving means can move the material to be dried in the lower layer of the fluidized bed in the first drying furnace 110 to the upper layer of the fluidized bed in the second drying furnace 210, and the second moving means is the first drying furnace The material to be dried in the upper layer of the fluidized bed at 110 may be moved to the lower layer of the fluidized bed in the second drying furnace 210. For example, the first moving means and the second moving means may be configured by a screw feeder or the like.

  Moreover, in the said embodiment, the drying system 100 comprised by two driers (1st drier 110, 2nd drier 210) was mentioned as the example, and was demonstrated. However, the drying system may be configured to include three or more drying ovens. In this case, the positional relationship and the connection relationship between the first drying furnace 110 and the second drying furnace 210 are the first drying furnace and the second drying furnace, and the second drying furnace and the third drying furnace. It is good to apply to each drying oven.

  The present invention can be used for a drying system for drying a material to be dried such as brown coal.

100 Drying system 110 first drying oven 112 d lower outlet 112 e upper outlet 210 second drying oven 212 c upper inlet 212 d lower inlet 250 first connecting pipe (first moving means)
260 2nd connecting pipe (2nd moving means)

Claims (3)

A first drying furnace that forms a fluidized bed by flowing a material to be dried with a fluidizing gas, and drying the material to be dried with the fluidizing gas,
The to-be-dried material dried by the first drying furnace is introduced, and the to-be-dried material introduced is fluidized by a fluidizing gas to form a fluidized bed, and the to-be-dried material is fluidized by the fluidizing gas. A second drying oven to further dry the
First moving means for moving the material to be dried in the lower layer of the fluidized bed in the first drying furnace to the upper layer of the fluidized bed in the second drying furnace;
A second moving means for moving the material to be dried in the upper layer of the fluidized bed in the first drying furnace to the lower layer of the fluidized bed in the second drying furnace;
A drying system characterized in that it comprises. The first drying furnace is
A lower outlet through which the lower layer material to be dried is delivered;
An upper outlet provided above the lower outlet, to which the material to be dried in the upper layer is delivered;
Have
The second drying furnace is
An upper inlet, into which the material to be dried delivered from the lower outlet is introduced;
A lower inlet provided below the upper inlet and into which the material to be dried delivered from the upper outlet is introduced;
Have
The first moving means includes a first connection pipe connecting a lower outlet of the first drying furnace and an upper inlet of the second drying furnace.
The second moving means includes a second connection pipe connecting the upper outlet of the first drying oven and the lower inlet of the second drying oven.
In the first drying oven and the second drying oven, the upper surface of the fluidized bed in the first drying oven is the upper surface of the fluidized bed in the second drying oven, the upper inlet of the second drying oven, and the second The drying system according to claim 1, wherein the drying system is configured to be above the lower inlet of the drying furnace. The first drying oven and the second drying oven are
The lower outlet of the first drying oven is disposed above the upper inlet of the second drying oven,
The drying system according to claim 1 or 2, wherein the upper outlet of the first drying oven is disposed above the lower inlet of the second drying oven.

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