JP6878875B2 - Fluidized bed system - Google Patents

Description

The present disclosure relates to a fluidized bed system that moves a fluidized bed from a first fluidized bed chamber in which a fluidized bed of a fluidized bed is formed to a second fluidized bed chamber.

A fluidized bed system using a fluidized bed formed by ejecting gas from below to above in a fluidized bed chamber containing particulate solids is a drying, combustion, gasification, and granulation of solids. 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 (temperature, atmosphere, etc.) of the fluidized bed, limit the installation area (installation volume), ensure ease of control, and the like. There are also things.

In a fluidized bed system including a plurality of fluidized bed chambers, as a technique for moving a solid substance (fluidized bed) from the first fluidized bed chamber to the second fluidized bed chamber, a conveyor after taking out the fluidized bed from the first fluidized bed chamber. A technique for moving to the second fluidized bed chamber (for example, Patent Document 1) has been developed.

JP-A-2002-09952

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

In view of such problems, it is an object of the present disclosure to provide a fluidized bed system capable of moving a fluidized medium while preventing changes in the properties of the fluidized medium.

In order to solve the above problems, the fluidized bed system according to one aspect of the present disclosure includes a first fluidized bed chamber in which a fluidized bed of a fluid medium is formed, and a first discharge port provided in the first fluidized bed chamber. A first communication pipe to which one end is connected to, a pump inlet to which the other end of the first communication pipe is connected, a pump chamber having a pump discharge port, and an upstream chamber provided with the pump inlet. A partition plate that divides the pump chamber into a downstream chamber provided with the pump discharge port and communicates the upstream chamber and the downstream chamber below the pump discharge port, and a partition plate that communicates the upstream chamber with the first flow rate in the upstream chamber. The fluidized gas is supplied, and the fluidized gas is supplied to the downstream chamber at a second flow rate, which is a flow rate at which the empty tower speed of the downstream chamber becomes a predetermined empty tower speed higher than the empty tower speed of the upstream chamber. A gas supply unit, a second communication pipe having one end connected to the pump discharge port of the pump chamber, and a second fluidized bed chamber having a second inlet to which the other end of the second communication pipe is connected. The partition plate is provided in the pump chamber so that the horizontal cross-sectional area of the downstream chamber gradually decreases from the lower part toward the pump discharge port .

Further, the height of the fluidized bed in the upstream chamber may be higher than that of the lower end of the partition plate.

Further, the pump discharge port may be provided on the ceiling of the downstream chamber.

It is possible to move the flow medium while preventing changes in the properties of the flow medium.

It is a figure explaining the fluidized bed system. It is a figure explaining the pump unit.

An embodiment of the present disclosure will be described in detail below with reference to the accompanying drawings. The dimensions, materials, other specific numerical values, etc. shown in such an embodiment are merely examples for facilitating understanding, and do not limit the present disclosure unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are designated by the same reference numerals to omit duplicate description, and elements not directly related to the present disclosure are omitted from the illustration. 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 fluidized medium will be described as an example. In FIG. 1, the gas flow is indicated by a solid arrow, the flow medium flow is indicated by a dash-dotted arrow, 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 unit 210, a second fluidized bed unit 220, a first communication pipe 230, and a pump unit 240. , The second communication pipe 250 and the central control unit 260 are included.

(Introduction unit 110, moisture sensor 120)
The introduction unit 110 includes a conveyor 112, a hopper 114, an introduction pipe 116, and an introduction valve 118. The conveyor 112 conveys lignite from the lignite source to the hopper 114. The hopper 114 temporarily stores the lignite conveyed by the conveyor 112. The introduction pipe 116 is a pipe that communicates the hopper 114 with the first fluidized bed portion 210 (first input port 212a of the first fluidized bed chamber 212). The introduction valve 118 is provided in the introduction pipe 116 and adjusts the opening degree of the introduction pipe 116.

The moisture sensor 120 measures the moisture content of the lignite introduced into the first fluidized bed portion 210 by the introduction portion 110. As the moisture sensor 120, for example, a moisture sensor such as a near infrared absorption method or a microwave absorption method 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, and a first heat transfer section 216.

The first fluidized bed chamber 212 is a container provided with a first input port 212a and a first discharge port 212b on the side wall constituting the first fluidized bed chamber 212. An introduction pipe 116 is connected to the first inlet 212a, and lignite is introduced into the first fluidized bed chamber 212 through the first inlet 212a. Then, the first fluidized bed chamber 212 accommodates the introduced lignite. Further, a gas discharge pipe 212c for discharging the gas in the first fluidized bed chamber 212 to the outside is connected to the ceiling of the first fluidized bed chamber 212.

The first fluidized gas supply unit 214 supplies the first fluidized gas (for example, water vapor) from the bottom surface of the first fluidized bed chamber 212. Specifically, the first fluidized gas supply unit 214 includes a wind box 214a, a first fluidized pipe 214b, and a first blower 214c. The air box 214a is provided below the first fluidized bed chamber 212, and the upper portion of the air box 214a is formed of a dispersive plate 214d that also functions as the bottom surface of the first fluidized bed chamber 212 and is breathable. The dispersion plate 214d is composed of, for example, a plate provided with a plurality of holes having a diameter smaller than the particle size of brown coal, or a plate provided with a nozzle.

The first flow pipe 214b is connected to the air box 214a. Further, the first flow pipe 214b is provided with a first blower 214c for feeding the first fluidized gas. Therefore, when the fluidized bed system 100 is operated, the first fluidized gas is supplied into the first fluidized bed chamber 212 from the bottom surface of 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. The first fluidized gas causes lignite to flow in the first fluidized bed chamber 212 to form a fluidized bed of lignite. Further, the first fluidized gas supply unit 214 brings the first fluidized gas into contact with the lignite to promote heat transfer between the lignite and the first heat transfer unit 216 by fluidization, thereby causing water contained in the lignite. Evaporate part.

The first heat transfer unit 216 is composed of, for example, a pipe through which a heat medium flows, and is arranged in the first fluidized bed chamber 212. The first heat transfer unit 216 heats lignite with the heat of the heat medium in the process of distributing the heat medium. Due to the configuration including the first heat transfer unit 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 transferred. Can be heated. Therefore, the drying of lignite by the first fluidized gas is further promoted.

In this way, in the first fluidized bed section 210, undried lignite is introduced into the first fluidized bed chamber 212, and the lignite is heated by the first fluidized gas supply section 214 and the first heat transfer section 216, and the lignite is heated. A part of the water is evaporated and removed from the water. On the other hand, to explain the flow of lignite, the first fluidized bed chamber 212 is passed through the first discharge port 212b, the first communication pipe 230, the pump unit 240, and the second communication pipe 250 according to the control by the central control unit 260 described later. The lignite will move from the inside into the second fluidized bed chamber 222. The movement of lignite through the first communication pipe 230, the pump unit 240, and the second communication pipe 250 will be described in detail later.

(Second fluidized bed portion 220)
The second fluidized bed section 220 includes a second fluidized bed chamber 222, a second fluidized gas supply section 224, and a second heat transfer section 226.

The second fluidized bed chamber 222 is a container provided with a second input port 222a and a second discharge port 222b on the side wall constituting the second fluidized bed chamber 222. A second communication pipe 250 is connected to the second input port 222a, and the first communication pipe 250 is passed through the first discharge port 212b, the first communication pipe 230, the pump unit 240, the second communication pipe 250, and the second input port 222a. Lignite is introduced from the fluidized bed chamber 212 into the second fluidized bed chamber 222. Then, the second fluidized bed chamber 222 accommodates the introduced lignite. Further, a gas discharge pipe 222c for discharging the gas in the second fluidized bed chamber 222 to the outside is connected to the ceiling of the second fluidized bed chamber 222.

The second fluidized gas supply unit 224 supplies the second fluidized gas (for example, water vapor) from the bottom surface of the second fluidized bed chamber 222. Specifically, the second fluidized gas supply unit 224 is configured to include the air box 224a, the second fluidized pipe 224b, and the second blower 224c, similarly to the first fluidized gas supply unit 214. To. The air box 224a is provided below the second fluidized bed chamber 222, and the upper portion of the air box 224a also functions as the bottom surface of the second fluidized bed chamber 222 and is formed of a breathable dispersion plate 224d. The dispersion plate 224d is composed of, for example, a plate provided with a plurality of holes having a diameter smaller than the particle size of brown coal, or a plate provided with a nozzle.

The second flow pipe 224b is connected to the air box 224a. Further, the second flow pipe 224b is provided with a second blower 224c for feeding the second fluidized gas. Therefore, when the fluidized bed system 100 is operated, the second fluidized gas is supplied into the second fluidized bed chamber 222 from the bottom surface of the second fluidized bed chamber 222 through the air box 224a.

In this way, the second fluidized gas is supplied into the second fluidized bed chamber 222 by the second fluidized gas supply unit 224. The second fluidized gas causes lignite to flow in the second fluidized bed chamber 222 to form a fluidized bed of lignite. Further, the second fluidized gas supply unit 224 evaporates a part of the water contained in the lignite by bringing the second fluidized gas into contact with the lignite.

The second heat transfer unit 226 is composed of, for example, a pipe through which a heat medium flows, and is arranged in the second fluidized bed chamber 222. The second heat transfer unit 226 heats the lignite with the heat of the heat medium in the process of distributing the heat medium. With the configuration including the second heat transfer unit 226, heat exchange is performed between the heat medium and the second fluidized gas in the second fluidized bed chamber 222, and the second fluidized gas moving upward is further transferred. Can be heated. Therefore, the drying of lignite by the second fluidized gas is further promoted.

The overflow portion 228 includes an overflow pipe 228a connected to the second discharge port 222b and an overflow valve 228b provided in the overflow pipe 228a. The overflow unit 228 sends out the lignite that has overflowed from the second discharge port 222b of the second fluidized bed chamber 222 to the outside. Specifically, lignite is introduced into the second fluidized bed chamber 222 from the first fluidized bed portion 210 (inside the first fluidized bed chamber 212) through the first communication pipe 230, the pump unit 240, and the second communication pipe 250. Then, the body integration of the introduced lignite and the volume of the fluidized bed increase. Then, the lignite (fluidized bed) overflows from the second discharge port 222b and is sent to the outside through the overflow pipe 228a.

(1st communication pipe 230, pump unit 240, 2nd communication pipe 250)
The first communication pipe 230 is a pipe having one end connected to the first discharge port 212b and the other end connected to the pump inlet 242a of the pump chamber 242 which constitutes the pump unit 240, which will be described later. In this embodiment, the pump inlet 242a is provided below the first outlet 212b. Therefore, the first communication pipe 230 is arranged so as to be inclined vertically downward from one end (first discharge port 212b side) to the other end (pump inlet 242a side). Therefore, the lignite introduced from the first fluidized bed chamber 212 into the first communication pipe 230 moves to the pump inlet 242a by its own weight.

FIG. 2 is a diagram illustrating the pump unit 240. In FIG. 2, the gas flow is indicated by a solid arrow, and the flow of a fluidized medium is indicated by a alternate long and short dash arrow. As shown in FIG. 2, the pump unit 240 includes a pump chamber 242, a partition plate 246, and a gas supply unit 248.

The pump chamber 242 is a container in which the pump inlet 242a is provided on the side wall 242c constituting the pump chamber 242 and the pump discharge port 242b is provided on the ceiling 242d constituting the pump chamber 242. As described above, the first communication pipe 230 is connected to the pump inlet 242a, and lignite is introduced from the first fluidized bed chamber 212 into the pump chamber 242 through the first communication pipe 230. The pump chamber 242 then accommodates lignite.

The partition plate 246 divides the inside of the pump chamber 242 into an upstream chamber 244a provided with a pump inlet 242a and a downstream chamber 244b provided with a pump discharge port 242b, and forms an upstream chamber 244a below the pump discharge port 242b. It communicates with the downstream chamber 244b. In the present embodiment, the partition plate 246 extends from the ceiling 242d of the pump chamber 242 into the pump chamber 242. That is, the tip (lower end) of the partition plate 246 is separated from the bottom surface of the pump chamber 242. In the present embodiment, the pump discharge port 242b is formed on the ceiling of the downstream chamber 244b.

The gas supply unit 248 supplies fluidized gas (for example, water vapor) from the bottom surface of the upstream chamber 244a, and supplies fluidized gas (for example, water vapor) from the bottom surface of the downstream chamber 244b.

More specifically, the gas supply unit 248 includes air boxes 248a and 248b, fluidized gas pipes 248c and 248d, and blowers 248e and 248f. The air box 248a is provided below the upstream chamber 244a, and the upper portion of the air box 248a also functions as the bottom surface of the upstream chamber 244a and is formed of a breathable dispersion plate 248 g. The air box 248b is provided below the downstream chamber 244b, and the upper portion of the air box 248b also functions as the bottom surface of the downstream chamber 244b and is formed of a ventilable dispersion plate 248h. The dispersion plates 248g and 248h are composed of, for example, a plate provided with a plurality of holes having a diameter smaller than the particle size of lignite, or a plate provided with a nozzle. In the present embodiment, the air box 248a and the air box 248b are adjacent to each other, and the boundary between the air box 248a and the air box 248b is located vertically below (for example, directly below) the lower end of the partition plate 246. The wind boxes 248a and 248b are arranged there.

The fluidized gas pipe 248c is connected to the air box 248a. The fluidized gas pipe 248c is provided with a blower 248e for feeding the fluidized gas. Further, the fluidized gas pipe 248d is connected to the air box 248b. The fluidized gas pipe 248d is provided with a blower 248f for feeding the fluidized gas.

The blowers 248e and 248f are controlled by the central control unit 260, which will be described later. The blower 248e supplies the fluidized gas to the upstream chamber 244a (wind box 248a) at the first flow rate, which is the flow rate at which the superficial velocity of the upstream chamber 244a is 1.0 Umf or more and 1.2 Umf or less. Here, Umf is the fluidization start speed (minimum fluidization speed). If it is less than 1.0 Umf, the fluidized medium does not flow and becomes a fixed layer, and if it is 1.0 Umf or more, the fluidized medium starts to flow and becomes a fluidized bed. Further, when the superficial velocity of the upstream chamber 244a exceeds 1.2 Umf, the amount of fluidized gas flowing back into the first communication pipe 230 increases. Therefore, by supplying the fluidized gas at the first flow rate by the blower 248e, it is possible to form a fluidized bed of lignite in the upstream chamber 244a while suppressing the backflow of the fluidized gas into the first communication pipe 230. The height of the fluidized bed formed in the upstream chamber 244a is higher than that of the lower end of the partition plate 246.

The blower 248f supplies fluidized gas to the downstream chamber 244b (wind box 248b) at a second flow rate, which is a flow rate at which the superficial velocity of the downstream chamber 244b becomes a predetermined superficial velocity higher than the superficial velocity of the upstream chamber 244a. To do. The superficial velocity of the downstream chamber 244b is a superficial velocity at which the maximum layer height of the fluidized bed formed in the downstream chamber 244b is larger than the flow rate at which the position (height) of the bent portion 252, which will be described later, is reached. Of the pulsating fluidized bed heights (layer heights), the minimum layer height is referred to as the minimum layer height, and the maximum layer height is referred to as the maximum layer height. The average layer height is a temporal average value of the pulsating layer height. Further, the superficial velocity of the upstream chamber 244a and the superficial velocity of the downstream chamber 244b are the superficial velocities at the lower end of the partition plate 246.

As described above, the partition plate 246 extends from the ceiling 242d of the pump chamber 242 into the pump chamber 242 in a state where the lower portion in the pump chamber 242 communicates with each other. That is, the upstream chamber 244a and the downstream chamber 244b are communicated at the lower part. Therefore, the fluidized bed (brown coal) formed in the upstream chamber 244a moves to the downstream chamber 244b.

Further, the blower 248f that supplies the fluidized gas to the downstream chamber 244b supplies the fluidized gas to the downstream chamber 244b at a second flow rate. Then, in the downstream chamber 244b, the lignite moved from the upstream chamber 244a reaches the pump discharge port 242b and moves to the second communication pipe 250 through the pump discharge port 242b.

In the present embodiment, the partition plate 246 is provided in the pump chamber 242 so that the horizontal cross-sectional area of the downstream chamber 244b gradually decreases from the lower portion toward the pump discharge port 242b (ceiling 242d). Therefore, the amount of air bubbles in the fluidized bed can be increased from the lower part of the downstream chamber 244b toward the pump discharge port 242b (upper part). This makes it possible for the lignite to reach a higher position. Therefore, the lignite can be smoothly moved from the lower part to the upper part of the downstream chamber 244b.

Returning to FIG. 1, the second communication pipe 250 is a pipe in which one end is connected to the pump discharge port 242b of the pump chamber 242 and the other end is connected to the second input port 222a. In the present embodiment, the pump discharge port 242b is provided below the second input port 222a. Further, the second communication pipe 250 has a bent portion 252 between one end and the other end. The second communication pipe 250 is arranged so that the bent portion 252 is located above one end and the other end.

(Central control unit 260)
The central control unit 260 is composed of a semiconductor integrated circuit including a CPU (Central Processing Unit), reads programs and parameters for operating the CPU itself from the ROM, and cooperates with RAM as a work area and other electronic circuits. As a result, the entire fluidized layer system 100 is managed and controlled. In the present embodiment, the central control unit 260 functions as the introduction control unit 262.

Specifically, the introduction control unit 262 first flows the brown coal sent from the overflow unit 228 of the second fluidized bed chamber 222 based on the measured value of the moisture sensor 120 so as to be dried to the target value. The residence time of lignite in the bed chamber 212 and the second fluidized bed chamber 222 is derived. For example, when the measured value of the moisture sensor 120 is relatively large, that is, when the water content of the undried brown coal is high, the residence time is long, and when the measured value of the moisture sensor 120 is relatively small, that is, When the moisture content of undried brown coal is low, the residence time is short.

Then, the introduction control unit 262 has the derived residence time, the average layer height of the fluidized bed formed in the first fluidized bed chamber 212, and the average layer height of the fluidized bed formed in the second fluidized bed chamber 222. Based on the above, the transfer speed of the conveyor 112, the opening degree of the introduction valve 118, and the opening degree of the overflow valve 228b are controlled. In the present embodiment, the introduction control unit 262 makes sure that the average layer height of the fluidized bed formed in the first fluidized bed chamber 212 is substantially equal to the height (position) of the first discharge port 212b. , The transfer speed of the conveyor 112, the introduction valve 118, and the overflow so that the average layer height of the fluidized bed formed in the second fluidized bed chamber 222 is substantially equal to the height (position) of the second discharge port 222b. The opening degree of the valve 228b is controlled.

As described above, according to the fluidized bed system 100 according to the present embodiment, the first communication pipe 230, the pump unit 240, and the second communication are communicated between the first fluidized bed chamber 212 and the second fluidized bed chamber 222. Connected by a pipe 250, the gas supply unit 248 supplies the fluidized gas to the upstream chamber 244a at the first flow rate and supplies the fluidized gas to the downstream chamber 244b at the second flow rate. As a result, lignite can be moved from the first fluidized bed chamber 212 to the second fluidized bed chamber 222. Therefore, unlike the conventional technique of moving between fluidized bed chambers using a conveyor, it is possible to avoid a situation where lignite is exposed to air during the moving process. Therefore, it is possible to prevent lignite from reacting with substances in the air or adsorbing substances in the air. That is, it is possible to avoid a change in the properties of lignite during the process of movement between the fluidized bed chambers.

In addition, dried lignite in a high temperature state may react with oxygen in the air and burn. For this reason, in the conventional technique of moving between fluidized bed chambers using a conveyor, it is necessary to make a device equipped with a drive unit such as a conveyor a sealed structure, to provide fire extinguishing equipment, etc., which increases the cost. There was a problem. However, the fluidized bed system 100 of the present embodiment is provided with a drive unit because it is a simple mechanism in which lignite moves through the first communication pipe 230, the pump unit 240, and the second communication pipe 250 partitioned from the outside. There is no need for a sealed structure or fire extinguishing equipment. Therefore, it is possible to reduce the cost.

Although the embodiments have been described above with reference to the accompanying drawings, it goes without saying that the present disclosure is not limited to such embodiments. It is clear that a person skilled in the art can come up with various modifications or modifications within the scope of the claims, and it is understood that they also naturally belong to the technical scope.

For example, in the above embodiment, lignite as a fluid medium has been described as an example. 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 pump discharge port 242b is provided on the ceiling 242d of the pump chamber 242 has been described as an example. Therefore, since the freeboard portion is not formed in the downstream chamber 244b, the downstream chamber 244b (pump chamber 242) can be miniaturized. However, the position of the pump discharge port 242b is not limited as long as it is arranged above the lower part of the pump chamber 242.

Further, in the above embodiment, the case where the partition plate 246 is provided in the pump chamber 242 so that the horizontal cross-sectional area of the downstream chamber 244b gradually decreases from the lower portion toward the pump discharge port 242b has been described as an example. However, the partition plate 246 may be provided so that the horizontal cross-sectional areas of the downstream chambers 244b are substantially equal. Further, the partition plate 246 may be provided in the pump chamber 242 so that the horizontal cross-sectional area of the downstream chamber 244b gradually increases from the lower portion toward the pump discharge port 242b.

Further, the first fluidized bed portion 210 and the second fluidized bed portion 220 may have the same configuration (modularization). Thereby, the manufacturing cost of the first fluidized bed portion 210 and the second fluidized bed portion 220 can be reduced. Further, the first fluidized bed chamber 212 and the second fluidized bed chamber 222 may be provided with outlets for discharging internal gas.

Further, the first heat transfer unit 216 and the second heat transfer unit 226 are not indispensable configurations.

The present disclosure can be used in a fluidized bed system for moving a fluidized bed from a first fluidized bed chamber in which a fluidized bed of a fluidized bed is formed to a second fluidized bed chamber.

100 Fluidized bed system 212 1st fluidized bed chamber 212b 1st discharge port 222 2nd fluidized bed chamber 222a 2nd inlet 230 1st communication pipe 242 Pump chamber 242a Pump inlet 242b Pump outlet 242d Ceiling 244a Upstream chamber 244b Downstream chamber 246 Partition plate 248 Gas supply unit 250 2nd communication pipe

Claims (3)

The first fluidized bed chamber in which the fluidized bed of the fluidized medium is formed,
A first communication pipe having one end connected to a first discharge port provided in the first fluidized bed chamber,
A pump chamber having a pump inlet and a pump outlet to which the other end of the first communication pipe is connected, and
The pump chamber is divided into an upstream chamber provided with the pump inlet and a downstream chamber provided with the pump discharge port, and a partition for communicating the upstream chamber and the downstream chamber below the pump discharge port. Board and
A fluidized gas is supplied to the upstream chamber at the first flow rate, and the superficial velocity of the downstream chamber becomes a predetermined superficial velocity higher than the superficial velocity of the upstream chamber. And the gas supply unit that supplies the fluidized gas to
A second communication pipe with one end connected to the pump outlet in the pump chamber,
A second fluidized bed chamber having a second inlet to which the other end of the second communication pipe is connected, and
Equipped with a,
The partition plate is a fluidized bed system provided in the pump chamber so that the horizontal cross-sectional area of the downstream chamber gradually decreases from the lower part toward the pump discharge port. The fluidized bed system according to claim 1, wherein the fluidized bed in the upstream chamber is higher than the lower end of the partition plate. The fluidized bed system according to claim 1 or 2 , wherein the pump discharge port is provided on the ceiling of the downstream chamber.

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