JP6710928B2 - Fluidized bed system - Google Patents

Description

The present invention relates to a fluidized bed system for moving a fluidized medium from a first fluidized bed chamber in which a fluidized bed of a fluidized medium is formed to a second fluidized bed chamber.

A fluidized bed system using a fluidized bed formed by ejecting gas from below to above a fluidized bed chamber in which particulate solid matter is housed is a method for drying, burning, gasifying and granulating solid matter. It is used in various fields such as. Such a fluidized bed system is provided with a plurality of fluidized bed chambers in order to change the conditions of the fluidized bed (temperature, atmosphere, etc.), limit the installation area (installation volume), and ensure controllability. There are also things.

In a fluidized bed system including a plurality of fluidized bed chambers, as a technique for moving solid matter (fluidized medium) from the first fluidized bed chamber to the second fluidized bed chamber, a conveyor after removing the fluidized medium from the first fluidized bed chamber To move the second fluidized bed chamber to the second fluidized bed chamber (for example, Patent Document 1), or to arrange the first fluidized bed chamber above the second fluidized bed chamber and to communicate the first fluidized bed chamber and the second fluidized bed chamber. A technique (for example, Patent Document 2) has been developed in which a fluid medium is connected by a pipe and the fluid medium is moved by its own weight through a communication pipe.

JP, 2002-095952, A Japanese Patent No. 4083409

However, in the technique using the conveyor as described in Patent Document 1, the fluidizing medium is exposed to air during the moving process, and thus the fluidizing medium reacts with substances in the air such as oxygen and water, In the case of a substance that adsorbs, there is a problem that the properties of the fluid medium change during the movement process.

The technique of varying the installation height of the fluidized bed chamber described in Patent Document 2 occupies a wide area, so that the installation location is limited. Further, there is a problem that one fluidized bed chamber needs to be installed at a high place, resulting in high installation cost.

Therefore, in view of such problems, an object of the present invention is to provide a fluidized bed system capable of moving a fluidized medium at low cost while preventing property changes of the fluidized medium.

In order to solve the above problems, a fluidized bed system of the present invention is formed separately from a first fluidized bed chamber in which a fluidized bed of a fluidized medium is formed, and a fluidized bed of a fluidized medium. The second fluidized bed chamber to be formed, a predetermined first location on the side wall forming the first fluidized bed chamber, and a height substantially equal to the first location on the side wall forming the second fluidized bed chamber. The first flow so that the bed height of the fluidized bed formed in the first fluidized bed chamber and the communication pipe communicating with the second location and extending in the substantially horizontal direction is higher than that of the first location. The pressure control unit includes an introduction control unit that controls the introduction amount of the fluidized medium that is introduced into the layer chamber, and a pressure control unit that maintains the second fluidized bed chamber at a lower pressure than the first fluidized bed chamber. The moving speed of the fluidized medium is derived based on the residence time of the fluidized medium in the bed chamber and the second fluidized bed chamber and the volumes of the first fluidized bed chamber and the second fluidized bed chamber, and from the first fluidized bed chamber moving speed of the fluidized medium to the second fluidized bed chamber, controls either the pressure of one or both of the derived in the first fluidized bed chamber so that the moving speed and the second fluidized bed chamber, introducing controller Is characterized in that the introduction speed of the fluidized medium into the first fluidized bed chamber is the derived moving speed.

Also, a first exhaust part for discharging gas from a first freeboard part formed above the fluidized bed in the first fluidized bed chamber, and a second freeboard formed above the fluidized bed in the second fluidized bed chamber. A second exhaust part for exhausting gas from the part, and the pressure control part has an exhaust flow rate of each of the first exhaust part and the second exhaust part according to the pressure in the first fluidized bed chamber and the second fluidized bed chamber. May be controlled.

In addition, an extraction unit for extracting a part of the fluidized medium that has accumulated in the lower portion of the first fluidized bed chamber may be further provided.

According to the present invention, it is possible to move a fluidized medium at low cost while preventing changes in the properties of the fluidized medium.

It is a figure explaining a fluidized bed system.

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 shown in the embodiments are merely examples for facilitating understanding of the invention, and do not limit the invention unless otherwise specified. In this specification and the drawings, elements having substantially the same function and configuration are denoted by the same reference numerals to omit redundant description, and elements not directly related to the present invention are omitted. To do.

(Fluidized bed system 100)
FIG. 1 is a diagram illustrating a fluidized bed system 100. In the present embodiment, a configuration in which the fluidized bed system 100 dries brown coal as a fluid medium will be described as an example. In FIG. 1, the gas flow is indicated by a solid arrow, the flow of the fluid medium is indicated by an alternate long and short dash line, and the signal flow is indicated by a dashed arrow. As shown in FIG. 1, the fluidized bed system 100 includes an introduction unit 110, a moisture sensor 120, a first fluidized bed section 210, a second fluidized bed section 230, a communication pipe 250, and a central control section 260. It is configured to include.

(Introduction means 110, moisture sensor 120)
The introducing means 110 conveys brown coal to the first fluidized bed section 210 (first fluidized bed chamber 212) from the hopper 114 and the hopper 114 that temporarily stores the brown coal transported by the conveyor 112 and the conveyor 112. And an introducing valve 116 for introducing. In the present embodiment, in the introducing unit 110, the bed height of the fluidized bed formed in the first fluidized bed chamber 212 is higher than the first location 212c described below, under the control of the introduction control unit 262 described below. The lignite is introduced into the first fluidized bed chamber 212 with the introduction amount such that.

The water content sensor 120 measures the water content of the brown coal introduced into the first fluidized bed section 210 by the introduction means 110. As the moisture sensor 120, for example, a moisture sensor of a near infrared absorption type, a microwave absorption type, or the like can be adopted.

(First fluidized bed section 210)
The first fluidized bed section 210 includes a first fluidized bed chamber 212, a first fluidized gas supply section 214, a first heat transfer section 216, an extraction section 218, a first exhaust section 220, and a first pressure. It is configured to include a sensor 222.

The first fluidized bed chamber 212 accommodates the brown coal introduced by the introduction unit 110. The first fluidizing gas supply unit 214 supplies the first fluidizing gas (for example, steam) from the bottom surface of the first fluidized bed chamber 212. More specifically, the first fluidized gas supply unit 214 is configured to include an air box 214a, a first flow pipe 214b, and a first blower 214c. The wind box 214a is provided below the first fluidized bed chamber 212, and the upper part of the wind box 214a also functions as a bottom surface of the first fluidized bed chamber 212 and is formed of a ventilable dispersion plate 214d. The dispersion plate 214d is composed of, for example, a plate provided with a plurality of openings having a diameter smaller than that of brown coal, or a plate having a nozzle provided with an opening having a diameter smaller than that of brown coal. ..

The first flow pipe 214b is connected to the wind box 214a, and the first flow pipe 214b is provided with a first blower 214c for feeding the first fluidized gas. Therefore, when operating the fluidized bed system 100, the first fluidizing gas is supplied from the bottom surface of the first fluidized bed chamber 212 into the first fluidized bed chamber 212 through the air box 214a.

In this way, the first fluidized gas is supplied into the first fluidized bed chamber 212 by the first fluidized gas supply unit 214, and the first fluidized gas causes the brown coal to flow in the first fluidized bed chamber 212 and the brown coal. Of the water contained in the brown coal is vaporized by contacting the first fluidizing gas with the brown coal while forming the fluidized bed of

The first heat transfer section 216 is formed of, for example, a pipe through which a heat medium flows, and is arranged in the first fluidized bed chamber 212. The 1st heat transfer part 216 heats a brown coal with the heat which a heat medium has in the distribution process of a heat medium. With the configuration including the first heat transfer section 216, heat exchange is performed between the heat medium and the first fluidized gas in the first fluidized bed chamber 212, and the first fluidized gas moving upward is further increased. It can be heated. Therefore, the drying of the brown coal by the first fluidizing gas is further promoted.

The extraction unit 218 includes an extraction pipe 218a connected to a lower portion of a side wall 212a forming the first fluidized bed chamber 212, and an extraction valve 218b provided in the extraction pipe 218a. A part of the brown coal retained in the lower part of the fluidized bed chamber 212 is extracted to the outside. The effect of the extraction portion 218 will be described in detail later.

The first exhaust part 220 is configured to include a first exhaust pipe 220a connected to the upper wall of the first fluidized bed chamber 212 and a first exhaust valve 220b provided in the first exhaust pipe 220a. Gas is discharged from the space (first freeboard portion 212b) formed above the fluidized bed in the layer chamber 212.

The first pressure sensor 222 measures the pressure in the first fluidized bed chamber 212 (the pressure in the first freeboard portion 212b).

Thus, in the first fluidized bed section 210, undried brown coal is introduced into the first fluidized bed chamber 212, and the first fluidized gas supply section 214 and the first heat transfer section 216 heat the brown coal, so that the brown coal A part of the water is vaporized and removed from this. On the other hand, describing the flow of the brown coal, the brown coal moves from the first fluidized bed chamber 212 into the second fluidized bed chamber 232 through the communication pipe 250 under the control of the central control unit 260 described later. The movement of brown coal through the communication pipe 250 will be described in detail later.

(Second fluidized bed section 230)
The second fluidized bed section 230 includes a second fluidized bed chamber 232, a second fluidized gas supply section 234, a second heat transfer section 236, an overflow section 238, a second exhaust section 240, and a second pressure sensor. 242 is included.

The second fluidized bed chamber 232 is formed separately from the first fluidized bed chamber 212, and accommodates the brown coal introduced from the inside of the first fluidized bed chamber 212 through the communication pipe 250. The second fluidizing gas supply unit 234 supplies the second fluidizing gas (for example, steam) from the bottom surface of the second fluidized bed chamber 232. More specifically, the second fluidized gas supply unit 234 is configured to include a wind box 234a, a second fluidized pipe 234b, and a second blower 234c, like the first fluidized gas supply unit 214. It The wind box 234a is provided below the second fluidized bed chamber 232, and the upper part of the wind box 234a also functions as a bottom surface of the second fluidized bed chamber 232, and is formed of a dispersion plate 234d that is ventilated. The dispersion plate 234d is composed of, for example, a plate provided with a plurality of openings having a diameter smaller than that of brown coal, or a plate having a nozzle provided with an opening having a diameter smaller than that of brown coal. ..

The second flow pipe 234b is connected to the wind box 234a, and the second flow pipe 234b is provided with a second blower 234c for feeding the second fluidizing gas. Therefore, when operating the fluidized bed system 100, the second fluidized gas is supplied from the bottom surface of the second fluidized bed chamber 232 through the air box 234a into the second fluidized bed chamber 232.

In this way, the second fluidized gas is supplied into the second fluidized bed chamber 232 by the second fluidized gas supply unit 234, and the second fluidized gas causes the brown coal to flow in the second fluidized bed chamber 232, and the brown coal. The second fluidized gas is brought into contact with the brown coal to vaporize a part of the water contained in the brown coal.

The second heat transfer section 236 is configured by, for example, a pipe through which a heat medium flows, and is arranged in the second fluidized bed chamber 232. The second heat transfer unit 236 heats the brown coal with the heat of the heat medium in the heat medium circulation process. With the configuration including the second heat transfer section 236, heat exchange is performed between the heat medium and the second fluidizing gas in the second fluidized bed chamber 232, and the second fluidizing gas moving upward is further increased. It can be heated. Therefore, the drying of the brown coal by the second fluidizing gas is further promoted.

The overflow section 238 is configured to include an overflow pipe 238a connected to an outlet provided at an upper portion of a side wall 232a forming the second fluidized bed chamber 232, and an overflow valve 238b provided in the overflow pipe 238a. The brown coal overflowed from the outlet of the second fluidized bed chamber 232 is sent to the outside. Specifically, when lignite is introduced into the second fluidized-bed chamber 232 from the first fluidized-bed portion 210 (inside the first fluidized-bed chamber 212) through the communication pipe 250, the volume of the introduced lignite, The volume of the fluidized bed increases. Then, the brown coal (fluidized bed) overflows from the outlet of the second fluidized bed chamber 232 (the connection point of the second fluidized bed chamber 232 with the overflow pipe 238a) and is sent to the outside through the overflow pipe 238a.

The second exhaust unit 240 is configured to include a second exhaust pipe 240a connected to the upper wall of the second fluidized bed chamber 232 and a second exhaust valve 240b provided in the second exhaust pipe 240a. Gas is discharged from the space (second freeboard portion 232b) formed above the fluidized bed in the layer chamber 232.

The second pressure sensor 242 measures the pressure in the second fluidized bed chamber 232 (the pressure in the second freeboard section 232b).

(Communication pipe 250)
The communication pipe 250 includes a predetermined first portion 212c on the side wall 212a forming the first fluidized bed chamber 212 and a predetermined second portion 232c on the side wall 232a forming the second fluidized bed chamber 232. To communicate. In the present embodiment, the first location 212c is located above the location where the extraction pipe 218a is connected, and the height of the first location 212c is substantially equal to the height of the second location 232c. The communication pipe 250 is arranged to extend in the horizontal direction.

Further, as described above, the introduction means 110 introduces brown coal into the first fluidized bed chamber 212 with an introduction amount such that the bed height of the fluidized bed formed in the first fluidized bed chamber 212 is higher than the first location 212c. To introduce. Therefore, the inside of the communication pipe 250 is filled with the fluidized bed of brown coal.

(Central control unit 260)
The central control unit 260 is composed of a semiconductor integrated circuit including a CPU (central processing unit), reads a program and parameters for operating the CPU itself from the ROM, and cooperates with a RAM as a work area and other electronic circuits. Then, the whole fluidized bed system 100 is managed and controlled. In the present embodiment, the central control unit 260 functions as the introduction control unit 262 and the pressure control unit 264.

Specifically, the introduction control unit 262 first controls the conveying speed of the conveyor 112 and the opening degree of the introduction valve 116 so that the bed height of the fluidized bed formed in the first fluidized bed chamber 212 is the first. The introduction amount of the fluidized medium introduced into the first fluidized bed chamber 212 is controlled so as to be above the point 212c.

On the other hand, the pressure control unit 264, based on the measurement value of the moisture sensor 120, inside the first fluidized bed chamber 212 so that the brown coal sent from the overflow portion 238 of the second fluidized bed chamber 232 is dried to the target value. And the residence time of the brown coal in the second fluidized bed chamber 232 is derived. For example, when the measured value of the moisture sensor 120 is relatively large, that is, when the moisture content of the undried brown coal is high, the residence time becomes long, and when the measured value of the moisture sensor 120 is relatively small, that is, If the moisture content of undried brown coal is low, the residence time will be short.

Then, the pressure control unit 264 derives the moving speed of the brown coal based on the volumes of the first fluidized bed chamber 212 and the second fluidized bed chamber 232 stored in the memory (not shown) and the derived retention time. .. Subsequently, the pressure control unit 264 refers to the measurement values of the first pressure sensor 222 and the second pressure sensor 242, and the inside of the second fluidized bed chamber 232 is maintained at a lower pressure than the inside of the first fluidized bed chamber 212, The exhaust flow rates of the first exhaust part 220 and the second exhaust part 240 are controlled so that the moving speed of the brown coal is the derived moving speed.

Then, the introduction control unit 262 maintains the introduction amount such that the bed height of the fluidized bed formed in the first fluidized bed chamber 212 is higher than the first location 212c, and the introduction into the first fluidized bed chamber 212 is performed. The conveyance speed of the conveyor 112 and the opening degree of the introduction valve 116 are controlled so that the introduction speed of the brown coal becomes equal to the movement speed.

As described above, since the communication pipe 250 is filled with the fluidized bed, the pressure in the second fluidized bed chamber 232 can be set lower than the pressure in the first fluidized bed chamber 212, so that The brown coal can be automatically moved to the two-fluidized bed chamber 232. Further, the configuration including the introduction control unit 262 and the pressure control unit 264 makes it possible to move the brown coal from the first fluidized bed chamber 212 to the second fluidized bed chamber 232 at a desired moving speed.

As described above, according to the fluidized bed system 100 according to the present embodiment, the brown coal can be moved only by adjusting the pressures of the first fluidized bed chamber 212 and the second fluidized bed chamber 232, and thus the conveyor Unlike the conventional technique of moving between the fluidized bed chambers by using, it is possible to avoid the situation where the brown coal is exposed to air in the moving process. Therefore, it is possible to prevent the brown coal from reacting with the substance in the air or adsorbing the substance in the air, and it is possible to avoid a change in the property of the brown coal during the moving process.

Further, since dried lignite in a high temperature state may react with oxygen in the air and burn, in the conventional technique of moving between fluidized bed chambers using a conveyor, an apparatus equipped with a drive unit such as a conveyor is used. There is a problem in that the cost becomes high because it is necessary to provide a sealed structure or to equip fire extinguishing equipment. However, the fluidized bed system 100 of the present embodiment has a simple mechanism in which the brown coal moves inside the communication pipe 250 partitioned from the outside due to the pressure difference (differential pressure), so that the device including the drive unit is sealed. No structure or fire extinguishing equipment is required, and the cost can be reduced. Further, since it is not necessary to make the installation heights of the first fluidized bed chamber 212 and the second fluidized bed chamber 232 different, it is possible to reduce the installation cost.

Further, for example, when the first fluidizing gas having a flow rate at which the lignite having the average particle diameter is optimally fluidized is supplied from the first fluidizing gas supply unit 214 (first blower 214c), the particle diameter larger than the average particle diameter is obtained. Some (or large mass) lignite is not fluidized. Further, since the first portion 212c to which the communication pipe 250 is connected is arranged above the first fluidized bed chamber 212, lignite having a large particle size is not guided to the communication pipe 250 and is not fed to the first fluidized bed chamber. It remains in 212.

Therefore, by providing the extraction part 218 for extracting a part of the brown coal that has accumulated in the lower portion of the first fluidized bed chamber 212, it becomes possible to extract the unfluidized brown coal to the outside, and the brown coal in the first fluidized bed chamber 212 can be extracted. Can be avoided. This makes it possible to avoid the situation where the fluidized bed is not formed due to the remaining brown coal.

Moreover, since the extraction unit 218 extracts the unfluidized lignite from the first fluidized bed chamber 212, the unfluidized lignite is not introduced into the second fluidized bed chamber 232, and remains in the second fluidized bed chamber 232. It is possible to omit the extraction part dedicated to brown coal (fluid medium).

The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but it goes without saying that the present invention is not limited to such embodiments. It is obvious to those skilled in the art that various alterations or modifications can be conceived within the scope of the claims, and it should be understood that these also belong to the technical scope of the present invention. To be done.

For example, in the above-described embodiment, lignite is described as an example of the fluid medium. However, the type of fluid medium is not limited as long as it is a particulate solid.

Further, in the above embodiment, the configuration in which the first portion 212c to which the communication pipe 250 is connected is located above the portion to which the extraction pipe 218a is connected has been described as an example. However, the first location 212c may be a location lower than the bed height of the fluidized bed, and is substantially equal to the location to which the extraction pipe 218a is connected, or below the location to which the extraction pipe 218a is connected. May be located at.

Further, in the above-described embodiment, the configuration in which the height of the first portion 212c and the height of the second portion 232c are substantially equal to each other and the communication pipe 250 extends in the horizontal direction has been described as an example. However, the height relationship between the first location 212c and the second location 232c is not limited, and the communication pipe 250 may be inclined in the vertical direction.

Further, in the above-described embodiment, the fluidized bed system 100 includes the first pressure sensor 222 and the second pressure sensor 242, and the pressure control unit 264 responds to the measurement values of the first pressure sensor 222 and the second pressure sensor 242. The configuration in which the second fluidized bed chamber 232 is maintained at a lower pressure than the first fluidized bed chamber 212 has been described as an example. However, if the pressure control unit 264 can maintain the inside of the second fluidized bed chamber 232 at a lower pressure than the inside of the first fluidized bed chamber 212, the first pressure sensor 222 and the second pressure sensor 242 are not essential configurations. For example, based on the flow rate of the first fluidizing gas that the first blower 214c supplies to the wind box 214a and the flow rate of the second fluidizing gas that the second blower 234c supplies to the wind box 234a, the second fluidized bed chamber The opening degree of the first exhaust valve 220b and the opening degree of the second exhaust valve 240b may be controlled so as to maintain the pressure of 232 lower than that of the first fluidized bed chamber 212.

INDUSTRIAL APPLICATION This invention can be utilized for the fluidized bed system which moves a fluidized medium from a 1st fluidized bed chamber in which a fluidized bed of a fluidized medium is formed to a 2nd fluidized bed chamber.

100 fluidized bed system 212 1st fluidized bed chamber 212a Side wall 212b 1st freeboard part 212c 1st location 218 Extraction part 220 1st exhaust part 232 2nd fluidized bed chamber 232a Side wall 232b 2nd freeboard part 232c 2nd Location 240 Second exhaust unit 250 Communication pipe 262 Introduction control unit 264 Pressure control unit

Claims (3)

A first fluidized bed chamber in which a fluidized bed of fluidized medium is formed;
A second fluidized bed chamber formed separately from the first fluidized bed chamber in which a fluidized bed of a fluidized medium is formed;
A predetermined first location on the side wall forming the first fluidized bed chamber communicates with a second location on the side wall forming the second fluidized bed chamber, the second location having substantially the same height as the first location. And a communication pipe extending in a substantially horizontal direction,
An introduction control unit that controls the introduction amount of the fluidized medium introduced into the first fluidized bed chamber so that the height of the fluidized bed formed in the first fluidized bed chamber is higher than the first location. When,
A pressure controller for maintaining the second fluidized bed chamber at a lower pressure than the first fluidized bed chamber;
Equipped with
The pressure control unit, based on the residence time of the fluidized medium in the first fluidized bed chamber and the second fluidized bed chamber, and the volumes of the first fluidized bed chamber and the second fluidized bed chamber, derives the moving speed of the fluidized medium, the moving velocity of the fluid medium from the first fluidized bed chamber to the second fluidized bed chamber, the derived said to be the moving speed first fluidized bed chamber and said second controlling either pressure of one or both of the fluidized bed chamber,
A fluidized bed system, wherein the introduction control unit sets an introduction speed of the fluidized medium into the first fluidized bed chamber as the derived moving speed. A first exhaust unit configured to discharge gas from a first freeboard unit formed above the fluidized bed in the first fluidized bed chamber;
A second exhaust part for exhausting gas from a second freeboard part formed above the fluidized bed in the second fluidized bed chamber;
Equipped with
The pressure control unit,
The fluidized bed according to claim 1, wherein exhaust flow rates of the first exhaust section and the second exhaust section are controlled according to pressures in the first fluidized bed chamber and the second fluidized bed chamber. system. The fluidized bed system according to claim 1 or 2, further comprising a withdrawal portion for withdrawing a part of the fluidized medium retained in a lower portion of the first fluidized bed chamber.

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