JP2006242454A - Fluidized bed furnace - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluidized bed furnace for improving reliability suitable for a fluidized bed type incinerator of incineration equipment and a facility. <P>SOLUTION: This fluidized bed furnace has a furnace part 3 for performing combustion, a diffusing part 11 arranged on the bottom side of the furnace part 3 and blowing off air for fluidizing a fluid medium 10, a hopper part 5 arranged under the diffusing part 11 and extracting the content in the furnace part 3, a straightening plate 13 arranged in the hopper part 5 and capable of expanding and reducing the opening area of an opening part, a straightening plate driving means 19 for expanding and reducing the opening area of the opening part of the straightening plate 13, a first temperature detecting means 15 for detecting the temperature on the furnace part 3 side rather than the straightening plate 13, and a second temperature detecting means 17 for detecting the temperature on the outlet part 5b side of the hopper part 5 rather than the straightening plate 13; and is constituted for driving the straightening plate driving means 9 in response to a temperature difference between the temperature detected by the first temperature detecting means 15 and the temperature detected by the second temperature detecting means 17. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fluidized bed furnace provided with a current plate, and more particularly to a fluidized bed furnace suitable for an incinerator or a fluidized bed type incinerator for equipment.

  Generally, in a fluidized bed furnace used as a fluidized bed incinerator for an incinerator or equipment, the contents in the furnace part, such as ash or incombustibles that could not be burned, are extracted to the outside. An extraction part is provided. Further, in the fluidized bed furnace, an air diffuser for blowing out air for fluidizing the fluidized medium in the fluidized bed is provided on the bottom side in the furnace, and the extraction part is provided below the air diffuser. ing. Normally, the incombustible material and the fluid medium that could not be combusted in the furnace part pass through a gap such as an air diffuser constituting the air diffuser, and move to the lower side of the air diffuser, that is, the extraction part.

  By the way, the extraction part has a cylindrical shape or a conical shape or a funnel shape in which the width gradually decreases as it goes downward. Thus, the moving speed of the fluid medium downward becomes relatively slow, and conversely, the fluid moving medium moves downwardly relatively slowly at the central portion along the central axis of the extraction portion. And, due to the difference between the peripheral part and the central part of the moving speed downward of the fluid medium, a phenomenon occurs that the fluid medium in the central part along the central axis of the furnace part falls off and becomes hollow, In some cases, the flow medium may flow poorly.

  In order to suppress the occurrence of such flow failure of the fluid medium, a rectifying plate is provided in the extraction portion. The opening part of the baffle plate is provided at a position corresponding to the peripheral part of the extraction part, and the position corresponding to the center part of the extraction part is closed. Further, the opening portion of such a rectifying plate has a certain opening area, and this opening area is selected in consideration of the cross-sectional area of the portion continuing to the furnace portion of the extraction portion and the opening size of the outlet portion. Yes. The size of the opening of such a current plate is usually larger than the gap of the air diffuser, etc., and accumulation of non-combustible materials that have passed through the air diffuser occurs. Considered difficult.

  However, if the non-combustible material includes a long material such as a wire, a rod-shaped member, or a belt-shaped member, the long material passes through the gap such as the diffuser tube of the diffuser portion in the longitudinal direction. There are cases where the extending direction changes between the current plate and the state where it is caught on the current plate. When a long object is caught on the current plate, other incombustible material that can pass through the opening of the current plate may accumulate on the current material. When such incombustibles accumulate on the current plate, cavitation occurs locally in the extraction portion, resulting in poor flow of the fluid medium.

  At this time, in the conventional fluidized bed furnace, if incombustibles accumulate on the rectifying plate, a fluid failure such as stopping the flow of the fluidized medium occurs, and if cavitation occurs locally in the extraction part, this is extracted into the furnace part. Since it is detected as a temperature difference between the inside and the inside, the temperature difference is detected to detect a flow failure, and when a flow failure is detected, the operation of the fluidized bed furnace is stopped. Then, after the operation of the fluidized bed furnace is stopped, the incombustible material accumulated on the current plate is removed to eliminate the fluid flow defect of the fluidized medium.

  In addition, as another conventional fluidized bed furnace, the heat transfer coefficient is detected from the temperature difference between the upper and lower parts of the fluidized bed formed in the furnace part to detect fluid flow failure due to the enlargement of the fluidized medium. There has been proposed a fluidized bed furnace in which a fluidized medium is extracted and a new fluidized medium is introduced to suppress fluid flow failure of the fluidized medium (see, for example, Patent Document 1). Furthermore, by detecting the temperature of the dense layer where the particle density of the fluidized medium formed on the bottom side of the furnace part is high and maintaining this detected temperature at the set value, the coal ash that is the fuel melts and forms a lump. The fluidized bed furnace which suppresses becoming and suppresses the flow defect of a moving medium is proposed (for example, refer patent document 2). In addition, a fluidized bed furnace provided with a foreign matter distributor capable of moving up and down at the extraction part, suppressing the accumulation of noncombustible materials by moving the foreign matter distributor, and suppressing the extraction part from being blocked by the accumulation of noncombustible substances. It has been proposed (see, for example, Patent Document 3).

JP 63-96407 (page 2-3, FIG. 1) JP-A-4-161701 (page 3-4, FIG. 2) JP-A-6-331106 (page 3-4, FIG. 1)

  As described above, in a fluidized bed furnace provided with a conventional rectifying plate, when non-combustible material or the like accumulates on the rectifying plate to cause a fluid flow failure of the fluidized medium, the operation of the fluidized bed furnace is stopped. For this reason, the fluidized bed furnace reliability is improved by eliminating the fluid flow failure of the fluidized medium due to the accumulation of non-combustible materials on the current plate, and suppressing the shutdown of the fluidized bed furnace due to the fluid flow failure of the fluidized medium. Need to improve.

  On the other hand, other conventional fluidized bed furnaces such as Patent Documents 1 to 3 do not take into account the poor flow of the fluidized medium due to accumulation of incombustibles on the rectifying plate, and incombustibles accumulate on the rectifying plate. The reliability of the fluidized bed furnace cannot be improved by eliminating the fluidity failure of the fluidized medium caused by the operation and suppressing the operation stop of the fluidized bed furnace due to the fluidity failure of the fluidized medium.

  An object of the present invention is to improve the reliability of a fluidized bed furnace.

  The fluidized bed furnace of the present invention is provided with a furnace section for performing combustion, an air diffuser section provided on the bottom side of the furnace section for blowing out air for fluidizing the fluid medium, and a lower portion of the air diffuser section. An extraction part for extracting contents in the furnace part, a rectifying plate installed in the extraction part and capable of expanding and reducing the opening area of the opening part, and an opening area of the opening part of the rectifying plate being enlarged and reduced A rectifying plate driving means for reducing, a first temperature detecting means for detecting a temperature on the furnace side of the rectifying plate, and a second temperature detection for detecting a temperature on the outlet portion side of the extraction part from the rectifying plate Means for driving the rectifying plate driving means according to the temperature difference between the temperature detected by the first temperature detecting means and the temperature detected by the second temperature detecting means. .

The rectifying plate has a shape in which a plurality of fin portions project radially from the central portion toward the side wall of the extraction portion, and a space between adjacent fin portions of the plurality of fin portions is an opening. The configuration. Further, the side wall of the extraction portion has a double wall structure of an outer wall and an inner wall, and at least one of the plurality of fin portions reaches the outer wall of the extraction portion, and the fin portion reaching the outer wall of the extraction portion A rectifying plate driving means provided outside the extraction portion is connected.
By adopting such a configuration, for example, the temperature difference between the temperature detected by the first temperature detecting means and the temperature detected by the second temperature detecting means deviates from a preset value or range, so that By detecting the flow failure of the fluid medium due to the accumulation of non-combustible material on the surface and expanding the opening area of the opening of the current plate, the non-combustible material deposited on the current plate is dropped and removed from the opening. Can do. Therefore, the flow failure of the fluidized medium due to the accumulation of incombustibles on the rectifying plate can be eliminated, the operation stop of the fluidized bed furnace due to the fluid flow failure of the fluidized medium can be suppressed, and the reliability of the fluidized bed furnace can be improved.

  According to the present invention, the reliability of a fluidized bed furnace can be improved.

  Hereinafter, an embodiment of a fluidized bed furnace to which the present invention is applied will be described with reference to FIGS. 1 and 2. FIG. 1 is a cross-sectional view schematically showing a schematic configuration of a fluidized bed furnace to which the present invention is applied. FIG. 2 is a diagram showing the shape of a rectifying plate of a fluidized bed furnace to which the present invention is applied.

  The fluidized bed furnace 1 of the present embodiment is used as an incinerator in a waste incineration facility for incinerating industrial waste and other garbage, and as shown in FIG. Fluidized bed type furnace unit 3, a hopper unit 5 provided on the bottom side of the furnace unit 3 and serving as an extraction unit for extracting the contents in the furnace unit 3, for example, ash and incombustibles, out of the furnace unit 3, It is formed by a discharge transport device 7 connected to the section 5. The furnace part 3 is provided with a dust inlet part 9 for putting garbage into the furnace part 3. Further, on the bottom side of the furnace part 3, a diffuser that constitutes an air diffuser that blows air for flowing the fluidized sand 10 serving as a fluid medium stored in the furnace part 3 upward in the furnace part 3. A trachea 11 is provided.

  The hopper portion 5 is provided below the diffuser tube 11 and has a funnel shape in which a cylindrical outlet portion 5b is provided at the lower end portion of the tapered portion 5a in which the width of the passage gradually decreases toward the bottom. Is formed. A rectifying plate 13 is installed in the tapered portion 5 a of the hopper portion 5. The discharge conveying device 7 is a screw conveyor type conveying device connected to the outlet portion 5 b of the hopper portion 5. A first thermometer 15 for detecting the temperature of the fluidized sand 10, which is a fluidized medium closer to the furnace part 3 than the rectifying plate 13, is provided above the air diffusion pipe 11 of the furnace part 3. A second thermometer 17 for detecting the temperature on the outlet portion 5b side of the hopper portion 5 relative to the rectifying plate 13 is provided below the rectifying plate 13 of the tapered portion 5a of the hopper portion 5.

  As shown in FIG. 2, the rectifying plate 13 is a member having a shape in which four fin portions 13 b project radially from the central portion 13 a toward the side wall of the hopper portion 5, and the adjacent fin portions 13 b and the hopper portion 5. A space surrounded by the taper portion 5 a is an opening 13 c of the rectifying plate 13. Note that the hopper portion 5 of the present embodiment has a double wall structure including an outer wall 5c and an inner wall 5d. In the current plate 13 of the present embodiment, two adjacent fin portions 13b among the four fin portions 13b pass through the inner wall 5d of the hopper portion 5 and reach the outer wall 5c. The fin portion 13b contacts the outer wall 5c and is supported by the outer wall 5c. On the other hand, the remaining two fin portions 13b out of the four fin portions 13b are in contact with the inner wall 5d and supported by the inner wall 5d.

  In the current plate 13 of this embodiment, the four fin portions 13b are movable, and the opening area of the opening portion 13c can be enlarged and reduced. Of the four fin portions 13b, the fin portion 13b reaching the outer wall 5c is connected to a motor 19 serving as a current plate driving means provided outside the hopper portion 5, as shown in FIG. . As the structure and operation of the four fin portions 13b for expanding and reducing the opening area of the opening 13c, various structures and operations can be selected as long as the opening area of the opening 13c can be expanded and reduced. For example, by rotating the motor 19 with a rotation axis in a direction along the extending direction of the fin portion 13b, the inclination angle can be made variable, or the lateral width of the fin portion 13b can be made variable. The opening area of the opening 13c can be enlarged and reduced. Further, as shown in FIG. 2, a cooling water pipe 13 d is provided in the fin portion 13 b of the rectifying plate 13.

  The first thermometer 15, the second thermometer 17, and the motor 19 are electrically connected to the control unit 21 via the wiring 23. The control unit 21 receives a signal from the first thermometer 15 and a signal from the second thermometer 17, and detects the temperature detected by the first thermometer 15 and the temperature detected by the second thermometer 17 from these signals. The operation of the fluidized bed furnace 1 is controlled so that the temperature difference between the two becomes the set value T ° C. In addition, when the temperature difference between the temperature detected by the first thermometer 15 and the temperature detected by the second thermometer 17 deviates from the set value T ° C., the control unit 21 of the present embodiment causes the motor 19 to supply the rectifying plate 13. A drive signal for expanding the opening area of the opening 13c is output, and the opening area of the opening 13c of the rectifying plate 13 is increased. Further, when the temperature difference between the temperature detected by the first thermometer 15 and the temperature detected by the second thermometer 17 returns to the set value T ° C., the control unit 21 of the present embodiment opens the opening 13c of the rectifying plate 13. A drive signal for reducing the opening area to the normal opening area is output, and the opening area of the opening 13c of the rectifying plate 13 is returned to the normal area.

  The operation of the fluidized bed furnace having such a configuration and the features of the present invention will be described. In the fluidized bed furnace 1 when used as an incinerator of a waste incineration facility, waste is supplied into the furnace part 3 from the waste inlet 9 and incinerated. At this time, an incombustible material or the like having a specified size or less passes through the gap of the air diffuser 11 and the opening 13c of the rectifying plate 13, and is discharged from the hopper 5 through the discharge transport device 7. While performing such an incineration process, the temperature of the fluidized sand 10 above the current plate 13, that is, the temperature of the fluidized sand 10 on the furnace unit 3 side is set to the temperature of the fluidized sand 10 below the current plate 13 by the first thermometer 15. Measure with the second thermometer 17. The control unit 21 operates the fluidized bed furnace 1 during normal operation so that the temperature difference between the temperature detected by the first thermometer 15 and the temperature detected by the second thermometer 17 becomes the set value T ° C. Control.

  However, if the incombustible material includes a long material such as a wire, a rod-like member, or a belt-like member, it passes through the gap such as the air diffuser tube 7 in the longitudinal direction, and is caught on the current plate 13, If incombustibles or the like are accumulated, cavitation occurs in the hopper portion 5, and the temperature difference between the upper and lower fluidized sand 10 on the rectifying plate 13 deviates from the set value T ° C., and the fluidized bed furnace 1 is operated. Even if controlled, the temperature difference does not become the set value T ° C. As described above, when the temperature difference between the temperature detected by the first thermometer 15 and the temperature detected by the second thermometer 17 deviates from the set value T ° C., the control unit 21 warns the operator or the like. And a drive signal for expanding the opening area of the opening 13c of the rectifying plate 13 is output to increase the opening area of the opening 13c of the rectifying plate 13. Thereby, the long thing caught from the opening part 13c of the baffle plate 13, the other incombustible material etc. which were deposited, etc. fall, and the flow defect of the fluidized sand 10 is eliminated, continuing the operation | movement of a fluidized bed furnace.

  Further, when the temperature difference between the temperature detected by the first thermometer 15 and the temperature detected by the second thermometer 17 returns to the initial set value, that is, the set value T ° C., the control unit 21 opens the opening 13c of the rectifying plate 13. A drive signal for reducing the opening area to the normal opening area is output, and the opening area of the opening 13c of the rectifying plate 13 is returned to the normal area. At this time, the operator receives an alarm or the like, confirms the temperature of the fluidized sand 10, and after the temperature difference returns to the initial set value, that is, the set value T ° C, the opening 13c of the rectifying plate 13 becomes the original opening area. Confirm to return.

  Thus, in the fluidized bed furnace 1 of this embodiment, the temperature difference between the temperature detected by the first thermometer 15 and the temperature detected by the second thermometer 17 deviates from the preset set value T ° C. When the fluid sand 10 serving as a fluid medium is in a state of poor flow, the control unit 21 outputs a drive signal for expanding the opening area of the opening 13c of the rectifying plate 13 to the motor 19 serving as the rectifying plate driving means. The opening area of the opening 13c of the current plate 13 is enlarged. As a result, the long material that has been caught from the opening 13c of the rectifying plate 13 that is the cause of the flow failure of the fluidized sand 10 or other incombustible material that has accumulated is dropped, and the fluid sand of the fluidized sand 10 that is the fluidized medium is flown. Can be resolved. Therefore, the flow failure of the fluidized medium due to the accumulation of incombustibles on the current plate can be eliminated, the operation stop of the fluidized bed furnace due to the fluid flow failure of the fluidized medium can be suppressed, and the reliability of the fluidized bed furnace can be improved.

  Further, when the temperature difference between the temperature detected by the first thermometer 15 and the temperature detected by the second thermometer 17 deviates from a preset set value T ° C., the opening area of the opening 13c of the rectifying plate 13 is expanded. By doing this, it is possible to remove long objects that have been caught from the opening 13c of the rectifying plate 13 during operation of the fluidized bed furnace, other incombustible substances that have accumulated, and the like. In addition, after the opening area of the opening 13c of the rectifying plate 13 is enlarged, the temperature difference between the temperature detected by the first thermometer 15 and the temperature detected by the second thermometer 17 becomes a preset set value T ° C. When returning, the opening area of the opening 13c of the rectifying plate 13 can be reduced and returned to the normal opening area. For this reason, the fluid flow defect of the fluidized medium can be resolved while continuing the operation of the fluidized bed furnace. Furthermore, since the fluid medium failure can be resolved while continuing the operation of the fluidized bed furnace, the frequency of operation stoppage due to the fluid medium flow defect can be reduced, and the fluidized bed furnace can contribute to stable combustion.

  Moreover, although the case where the funnel-shaped hopper part 5 was provided as an extraction part was illustrated in this embodiment, the thing of various shapes, such as cylindrical shape and a cone shape, can be used as an extraction part. Similarly, the diffuser unit is not limited to the diffuser tube 11 shown in the present embodiment, and various configurations and structures can be used. Further, in the present embodiment, the case where it is used as an incinerator of a waste incineration facility is illustrated, however, the present invention includes an extraction part provided with a rectifying plate on the bottom side of the furnace part, and non-combustible on the rectifying plate. If there is a possibility of deposits, it can be applied to a fluidized bed furnace used for various purposes.

  As described above, the present invention is not limited to the fluidized bed furnace of the configuration and application of the present embodiment, and can be used for various configurations and applications as long as it has an extraction part provided with a rectifying plate on the bottom side of the furnace part. Applicable to floor furnace.

It is sectional drawing which shows typically schematic structure of one Embodiment of the fluidized-bed furnace to which this invention is applied. It is a figure which shows the shape of the baffle plate of one Embodiment of the fluidized-bed furnace to which this invention is applied, (a) is a top view, (b) is a side view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fluidized bed furnace 3 Furnace part 5 Hopper part 5a Taper part 5b Outlet part 10 Fluid sand 11 Aeration pipe 13 Current plate 15 1st thermometer 17 2nd thermometer 19 Motor 21 Control part

Claims (3)

A furnace part for performing combustion, a diffuser part for blowing air for fluidizing a fluid medium provided on the bottom side of the furnace part, and a content in the furnace part provided below the diffuser part An extraction portion for extracting the current, a rectifying plate installed in the extraction portion and capable of expanding and reducing the opening area of the opening, and a rectifying plate driving for expanding and reducing the opening area of the opening of the rectifying plate Means, a first temperature detecting means for detecting the temperature on the furnace part side of the rectifying plate, and a second temperature detecting means for detecting the temperature of the outlet portion side of the extraction part from the rectifying plate. And a fluidized bed furnace in which the rectifying plate driving means is driven in accordance with a temperature difference between the temperature detected by the first temperature detecting means and the temperature detected by the second temperature detecting means. The current plate has a shape in which a plurality of fin portions project radially from the central portion toward the side wall of the extraction portion, and a space between adjacent fin portions of the plurality of fin portions is an opening. The fluidized bed furnace according to claim 1. The side wall of the extraction portion has a double wall structure of an outer wall and an inner wall, and at least one of the plurality of fin portions reaches the outer wall of the extraction portion, and the fin that reaches the outer wall of the extraction portion The fluidized bed furnace according to claim 2, wherein the rectifying plate driving means provided on the outside of the extraction part is connected to the part.

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