JP2006189251A - Fluidized-bed furnace - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluidized-bed furnace enabling discharge of noncombustibles which can smoothly minimize thermal loss with a simple furnace structure. <P>SOLUTION: In this fluidized-bed furnace, a furnace floor part 12 is provided with air diffusion means 13 for introducing fluidizing air; an incombustible extraction opening 20 is formed at the center of the furnace floor part 12; and an incombustible extraction chute 19 is connected to the lower side of the opening. The fluidized-bed furnace is so structured that a plurality of auxiliary nozzles 18 are arranged on the side wall of the opening 20 oppositely to one another; each auxiliary nozzle 18 has a structure for jetting auxiliary air downward from the horizontal direction at a certain angle; and noncombustibles are collected in the incombustible extraction chute while facilitating discharge toward the incombustible extraction chute 19 of the noncombustibles guided to the opening 20 by the jetting of the auxiliary air. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fluidized bed furnace in which an incinerated product is mixed and fluidized with a fluidized medium for combustion treatment, and more particularly to a fluidized bed furnace having a mechanism for extracting and removing incombustible materials contained in the incinerated product.

Conventionally, fluidized bed furnaces have been widely used as equipment for incineration of municipal waste, sewage sludge, industrial waste and the like. The fluidized bed furnace is an incinerator in which a fluid medium heated to a high temperature is brought into contact with the incinerator while flowing with fluid air introduced from the lower part of the furnace body, and the incinerated substance is burned by the thermal energy of the fluid medium. There is an advantage that a uniform and stable combustion process can be performed without causing problems due to high temperatures.
However, incinerated materials accumulated in the landfill may contain incombustible materials such as wires, rubble, stones, and glass. If these incombustible materials are mixed, uniform and stable combustion is possible. There is a problem that processing cannot be performed and a failure of the apparatus is caused.
Therefore, various fluidized bed furnaces have been proposed and put into practical use in which an incombustible discharge port is provided in a part of the hearth to improve the above problems.

For example, in Patent Document 1 (Japanese Utility Model Publication No. 51-109669), a plate-shaped rectifier is provided at the bottom of the furnace body, and non-incinerated materials are discharged from an unincinerated material discharge pipe provided at the lower end of the plate-shaped rectifier. A method is described in which an air blowing port is provided below the unincinerated material discharge pipe, the unincinerated material is sunk by a wind sieve, and discharged out of the furnace by a screw.
However, in this method, sand and non-incinerated materials are separated by the blown air, and the non-incinerated materials may be concentrated in the non-incinerated material discharge pipe, and the discharge pipe may be blocked. In addition, the rectifier and other structures installed in the fluidized bed furnace are complicated, and there is a risk that they will be blocked by non-incinerated materials.
Moreover, in patent document 2 (Unexamined-Japanese-Patent No. 4-208304), although the incombustible discharge port is provided in the central valley part of the hearth which inclines continuously, the width and area of an incombustible discharge port are prescribed | regulated, When the furnace becomes large, a large amount of sand must be extracted, which causes a problem that heat loss increases.

Patent Document 3 (Japanese Patent No. 2037555) discloses an incombustible material discharge port formed at the bottom of the inclined hearth and introduced into a plurality of partitioned air boxes at the bottom of the hearth. Discloses a fluidized bed furnace in which the size is gradually reduced toward the center.
Further, Patent Document 4 (Japanese Patent No. 2947946) includes an air supply pipe provided with a flow rate adjusting valve in each of the wind boxes divided into three or more sections, and the air dispersion plate is directed downward toward the furnace center. The structure which made it incline and provided the incombustible discharge port in the inclination lower end is disclosed.
However, in these structures, when the flow of the fluid medium at the incombustible material discharge port is slow, a non-fluidized area of the fluid medium is created at the boundary between the incombustible material discharge port and the wind box, and the movement of the incombustible material may be hindered In order to eliminate this non-fluidized zone, a large amount of sand must be extracted, resulting in a large heat loss.

In Patent Document 5 (Japanese Utility Model Publication No. 4-122926), an air nozzle is provided on the wall surface in the vicinity of the incombustible discharge port, and the non-fluidization region of the fluid medium generated immediately above the discharge port is broken down or not flowed. Although a configuration is disclosed in which the generation of the conversion zone is suppressed, in this configuration, it is always possible to discharge the incombustible material that is sinking in the hearth, but it is dispersed in the fluidized bed, such as wires and stitches. However, incombustible materials that start to settle when they reach a certain concentration range cannot be discharged unless the flow medium, the flow direction and flow rate of these incombustible materials are matched, and there is a problem that these incombustible materials remain. is there.
Furthermore, in Patent Document 6 (Japanese Patent Laid-Open No. 9-236227), an aeration device is provided on the inner surface of the incombustible discharge port to form a swirl flow, and the swirl flow causes the vicinity of the incombustible discharge port to flow to the incombustible material. In this case, if the swirl flow is too strong, a large amount of incombustible material falls into the incombustible material discharge port, and the discharge port may be blocked. In addition, fluidized bed furnaces have various operating conditions such as superficial velocity, air ratio, combustion temperature, etc. for the purpose of maintaining the optimal combustion state and suppressing the generation of toxic substances, etc. The swirl flow is generated after satisfying these conditions. Therefore, the furnace structure and the control mechanism are complicated.

Japanese Utility Model Publication No. 51-109669 JP-A-4-208304 Japanese Patent No. 2037555 Japanese Patent No. 2947946 Japanese Utility Model Publication No. 4-122926 Japanese Patent Laid-Open No. 9-236227

As described above, various methods for extracting noncombustible materials in a fluidized bed furnace have been proposed. However, in order to discharge noncombustible materials smoothly and with minimal heat loss, it is necessary to solve the following problems. .
That is, if a non-fluidized zone is formed in the vicinity of the incombustible discharge port, the movement of the non-flammable material will be inhibited.If a large amount of fluidized medium is extracted to prevent the formation of the non-fluidized zone, the heat loss will be large. If the incombustible material is not uniform and is discharged in a lump, the incombustible material outlet will be blocked.In particular, it is difficult to control the swirl flow in the structure where the swirl flow is forcibly formed to extract the incombustible material. Yes, if the swirl is too strong, a large amount of incombustible material will fall into the incombustible discharge port, and the discharge port will be blocked. When the concentration reaches a concentration range dispersed in the fluidized bed, such as wires and stitches, sedimentation will start. There is a problem that incombustible materials cannot be discharged unless the flow medium, flow direction, and flow speed of these incombustible materials are matched.
Accordingly, in view of the problems of the prior art described above, an object of the present invention is to provide a fluidized bed furnace that can discharge incombustible materials smoothly and with minimal heat loss with a simple furnace structure. To do.

Therefore, in order to solve such problems, the present invention is a fluidized bed furnace that performs combustion treatment while mixing and flowing a fluid medium and an incinerated material mixed with incombustible material having a specific gravity greater than that of the fluid medium. In a fluidized bed furnace in which a diffuser for introducing fluidized air into the floor is provided, an incombustible material extraction opening is formed in the center of the hearth portion, and an incombustible material extraction chute is connected below the opening. ,
A plurality of auxiliary nozzles are disposed opposite to the side wall of the opening, and the auxiliary nozzles eject auxiliary air at an angle downward from the horizontal direction.
The discharge of the incombustible material guided to the opening by the ejection of the auxiliary air to the incombustible material extraction chute side is promoted.

  In this case, the opening is a circular opening formed by a circular peripheral wall that extends downward (preferably vertically downward) as a side wall, and a plurality of auxiliary nozzles are arranged opposite to the upper end side of the opening on the hearth side of the peripheral wall, The auxiliary nozzle is specified as a structure that ejects auxiliary air at an angle downward from the horizontal direction.

Further, the opening is a groove-shaped incombustible material extraction opening provided in the center of the hearth part, and the bottom surface of the opening is an inclined part inclined downward from at least one of the opening end parts. Incombustible material extraction chute is connected,
The auxiliary nozzle is disposed opposite to both side walls facing and extending in parallel with the groove-shaped incombustible material extraction opening, and the auxiliary nozzle is specified as a structure that ejects auxiliary air at an angle downward from the horizontal direction. Also good.

  In this case, one or more auxiliary nozzles are arranged oppositely and not symmetrically on the side wall of the opening, and the auxiliary air introduced from the auxiliary nozzle is divided into two systems, an opening region and an incombustible material extraction chute region. The flow rate is controlled by dividing so that the superficial velocity decreases in the order of the upper or lower hearth of the opening, the upper end of the opening (above the inclined part), and the lower part of the opening (above the incombustible material extraction chute). The flow rates of the flow air and the auxiliary air are respectively controlled, and the non-combustible material can be collected in the non-combustible material extraction chute by the difference in specific gravity between the fluid medium and the non-combustible material.

  According to this invention, it is configured such that the superficial velocity decreases in the order of the upper side of the hearth part on both sides or around the opening, the upper end of the opening (above the inclined part), and the lower part of the opening (above the incombustible material extraction chute). The incombustible material can be reliably collected in the incombustible material extraction chute by the difference in the superficial velocity and the difference in specific gravity between the fluid medium and the incombustible material.

  Further, in the present invention, both sides of the side wall constituting the opening or a hearth portion around the side wall is formed by a horizontal floor so that the superficial velocity above the incombustible material extraction chute is smaller than the superficial velocity above the horizontal floor. In addition, it is preferable that the flow rates of the flow air and the auxiliary air are respectively controlled so that the incombustible material is collected in the incombustible material extraction chute due to a difference in specific gravity between the fluid medium and the incombustible material. As a result, it is possible to appropriately maintain the combustion state of the incinerated material and to smoothly discharge the incombustible material.

  According to this invention, when both sides of the side wall constituting the opening or the surrounding hearth part is formed of a horizontal floor, it is not necessary to incline the hearth part as in the prior art. The non-combustible material can be surely removed without providing a slope in the hearth and forming a fixed swirling flow that governs the movement of the fluid medium in the furnace as in the prior art. It can be collected in the incombustible material extraction chute, the furnace structure and the control mechanism can be simplified, and furthermore, the formation of the non-fluidized zone can be prevented, so the incombustible material can be extracted smoothly. In addition, since it is not necessary to discharge a large amount of fluid medium, heat loss can be minimized.

  The plurality of auxiliary nozzles are specifically provided in a direction substantially perpendicular to the side wall (side wall forming a vertical surface extending downward) of the noncombustible material extraction opening. It is preferable that the auxiliary air be ejected at an angle downward from the horizontal direction from the ejection hole drilled obliquely below the tip.

  Furthermore, the plurality of auxiliary nozzles are provided in a direction substantially perpendicular to the side wall of the incombustible material extraction opening, and the auxiliary nozzles are disposed below the horizontal direction from the ejection holes drilled obliquely downward at the tip thereof. It is preferable that the auxiliary air be ejected at an angle.

  Further, in the present invention, the superficial velocity is varied so that the flowing medium forms a downward flow above the incombustible discharge outlet, and the hearth around the opening (above the inclined portion) and both sides of the opening or around the opening. Since the fluidized medium is fluidized in the section, the incinerated material is suitably mixed and flowed with the fluidized medium to appropriately maintain the combustion state, and the incombustible material is smoothly extracted by the downward flow above the incombustible material outlet. Can do.

  Further, the auxiliary nozzle has a structure that ejects auxiliary air at an angle downward from the horizontal direction, and it is preferable that the discharge of the incombustible material is promoted by the ejection of the auxiliary air, thereby forming the downward flow. This can be promoted, and it is possible to prevent the formation of a non-fluidized zone in the vicinity of the incombustible discharge outlet, thereby achieving smooth discharge of the incombustible material.

As described above, according to the present invention, since the auxiliary nozzle is configured to eject auxiliary air at an angle downward from the horizontal direction, formation of the downflow can be promoted, and the nonflammable material outlet is not in the vicinity. Formation of a fluidized zone can be prevented, and smooth discharge of incombustibles can be achieved.
In particular, by introducing a small amount of auxiliary air, the flow of the incombustible material dispersed in the furnace and the fluidized medium can be combined to enable smooth discharge of the incombustible material, and the fluidized medium can be discharged to minimize heat loss. Furthermore, a simple structure and control mechanism can be obtained as compared with a conventional fluidized bed furnace.

  Further, in the above invention, the non-combustible material can be obtained by adjusting the jet length of the auxiliary air introduced from the plurality of auxiliary nozzles by adopting a structure in which the auxiliary nozzle ejects the auxiliary air at an angle downward from the horizontal direction. An ejection jet non-reaching region can be formed at the center of the extraction opening. Thereby, even incombustibles having a relatively small specific gravity can be reliably discharged without being blocked by the auxiliary air.

Further, by controlling the introduction amount of the auxiliary air and the flowing air so that the superficial velocity in the furnace is different, the nonflammable is caused by the superficial velocity difference and the specific gravity difference of the fluid medium and the noncombustible material. Can be reliably collected on the non-combustible material extraction chute, and the hearth part is inclined as in the prior art, or each on the hearth dispersion plate that governs the movement of the fluid medium in the furnace. There is no need to change the amount of air ejected from the wind box to form a swirling flow, and the furnace structure and control mechanism can be simplified.
Furthermore, since formation of a non-fluidization zone can be prevented, non-combustible materials can be smoothly extracted, and since it is not necessary to discharge a large amount of fluid medium, heat loss can be minimized.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, but are merely illustrative examples. Not too much.
The treatment target of the fluidized bed furnace according to the present embodiment is mainly combustible incineration materials such as general waste, industrial waste, sewage sludge, and the incineration materials include, for example, wire, rubble, stone, glass, tires, It is assumed that an incombustible material having a specific gravity greater than that of the fluid medium is mixed, such as building waste.

FIG. 1 is a diagram showing a fluidized bed furnace according to Embodiment 1 of the present invention, and FIG. 2 is a perspective view showing the entire configuration of the fluidized bed furnace shown in FIG. is there.
First, the overall configuration of the fluidized bed furnace according to the present embodiment will be described with reference to FIG. A fluidized bed furnace 10 according to this embodiment includes a square or cylindrical (not shown) furnace main body 11 as shown in the figure, and a horizontal hearth part 12 formed at the bottom of the furnace main body 11. The hearth 12 is provided with an air dispersion plate (not shown) provided with a plurality of flow air introduction nozzles (air dispersion nozzles) 13 horizontally at a position facing the inside of the furnace, An air box 14 is provided below the air dispersion plate to temporarily retain the flowing air. The wind box 14 is divided into a plurality of partitions by vertical partition plates 15a and 15b. Note that the wall surface facing the opening 20 of the partition plate 15 a functions as the side walls 201 and 202 of the opening 20.

1A and 1B are diagrams showing a fluidized bed furnace according to a first embodiment of the present invention, in which FIG. 1A is a plan view showing a hearth part, and FIG. 1B is a sectional view taken along line XX in FIG. (C) is a cross-sectional view taken along line XX according to another form of (b), and the side walls 201, 202 constituting the opening 20 are formed on both sides of the side walls 201, 202. 202 is formed by the inclined floor 12 in which the hearth portions on both sides are inclined toward the opening, and (d) is a sectional view taken along line YY of (a).
The air dispersion plate is provided with a plurality of flow air introduction nozzles (air dispersion nozzles) 13 as shown in FIG. From the flow air introduction nozzle 13, flow air for flowing the flow medium and the incineration material introduced above the air dispersion plate is ejected. The flow rate of the flowing air is determined by the flow rate of air introduced into the wind box 14, and the flow rate of air introduced into the wind box 14 can be controlled by an air supply pipe, a flow rate adjustment valve, and the like (not shown). In this embodiment, uniform flow control is performed on the plurality of wind boxes 14, and a single air flow control mechanism is provided. At that time, a plurality of air flow rate control mechanisms may be provided, and different air flow rates may be introduced into the plurality of partitioned air boxes 14.
Moreover, as shown in FIG.1 (d), the side wall 201 extended in parallel with an up-down direction in Fig.1 (a) in the center of the two wall surfaces which the said furnace main body 11 opposes among the said hearth parts 12. 202 and a groove-like opening 20 having an inclined surface 16 whose bottom surface is tapered downward toward the center incombustible material extraction chute 17 are formed, and the opening is used as an incombustible material extraction opening 20. . An incombustible material extraction chute 17 is connected from the end of the incombustible material extraction opening 20 through an inclined portion 16. Below the incombustible material extraction chute 17, a screw feeder for transferring the extracted incombustible material and the fluid medium, a magnetic separator for separating the incombustible material and the fluid medium, a vibrating sieve, a fluid medium classifier, and the like are provided. It is preferable that a fluid medium circulating means for returning the separated fluid medium to the furnace body 11 is provided.

A plurality of auxiliary nozzles 18 are provided at predetermined intervals along the opening end direction in contact with the hearth portion 12 on the upper end side of the side walls 201 and 202 formed vertically toward the vertically lower side of the incombustible material extraction opening 20. (18a, 18b) are arranged. As shown in FIGS. 1A, 1B and 1D, the auxiliary nozzle 18 is installed at a predetermined interval on the longitudinal side wall of the incombustible material extraction opening 20 to assist the discharge of the incombustible material. The auxiliary air is jetted out.
The auxiliary air introduced from the auxiliary nozzle 18 is divided into two or more systems and the flow rate is controlled, and the flow rate is different between the auxiliary nozzle 18a located in the inclined portion region and the auxiliary nozzle 18b located in the incombustible material extraction chute region. It has a control mechanism.

  An example of the auxiliary nozzle 18 is shown in FIG. In the auxiliary nozzle 18, a thick member at the tip is obliquely drilled to form a tapered portion 18c, and an ejection hole 18d is opened on the lower surface of the tapered portion 18c. Further, the auxiliary air ejected from the ejection hole 18d is configured to be ejected at an angle downward from the horizontal direction. Preferably, the downward angle is 10 ° to 45 °.

The superficial velocity in the furnace body 11 is controlled by the flow rates of flow air and auxiliary air introduced from the flow air introduction nozzle 13 and the auxiliary nozzles 18a and 18b, respectively.
The superficial velocity above the hearth on both sides of the incombustible material extraction opening 20 is controlled by the flow air introduced from the flow air introduction nozzle 13, and the auxiliary air introduced from the auxiliary nozzle 18a The superficial velocity above the inclined portion is controlled, and the superficial velocity above the incombustible material extraction chute is controlled by the auxiliary air introduced from the auxiliary nozzle 18b.
In this embodiment, control is performed so that the superficial velocity above the hearth portion, the superficial velocity above the inclined portion, and the superficial velocity above the incombustible material extraction chute are decreased in this order. At this time, it is preferable to control the superficial velocity above the inclined portion to be about 90% of the superficial velocity above the hearth portion.
Moreover, regarding each air introduction flow rate, it is set as the flow volume which a fluidized medium and an incombustible material fluidize on the opening 20 above the hearth part 12 and the inclination part 16, and the incombustible material extraction chute 17 below the opening 20 is carried out. In the upper part, the flow rate is a flow rate at which a downward flow of the fluid medium is formed.

Due to the difference in the superficial velocity and the difference in specific gravity between the fluid medium and the incombustible material, the incombustible material is reliably collected in the incombustible material extraction chute. Further, by setting the respective introduction flow rates as described above, the incinerated material is suitably mixed and flowed with the fluid medium so that the combustion state is appropriately maintained, and the incombustible material can be smoothly extracted by the downward flow. It becomes possible.
As described above, according to the present embodiment, the movement of the fluid medium is controlled in the furnace by providing an inclination to the hearth part or changing the superficial velocity on the hearth dispersion plate as in the prior art. Incombustible materials can be reliably collected in the incombustible material extraction chute without forming a swirling flow, and the furnace structure and control mechanism can be simplified.

Further, as a first application example of the first embodiment, FIG. 4 shows an entire configuration of a fluidized bed furnace having an inclined bed, and FIG. 1 (c) shows a side sectional view of the hearth part.
As shown in FIG. 4, the hearth part 12 is inclined downward from the facing furnace wall side of the furnace body 11 toward the center, and is parallel to the valley part at the center of the hearth part 12 along the valley part. The extending side walls 201 and 202 and the bottom surface thereof are provided with a groove-shaped incombustible material extraction opening 20 having an inclined surface 16 that is inclined downward toward the center incombustible material extraction chute 17 in a tapered shape. As shown in FIG. 1 (c), a plurality of auxiliary nozzles 18 are arranged opposite to the side walls 201, 202 of the incombustible material extraction opening 20, and the opening is similar to the fluidized bed furnace shown in FIG. An inclined portion 16 is provided from the end of 20 toward the center, and an incombustible material extraction chute 17 is connected to the center of the inclined portion.
When a large amount of incombustible material with high specific gravity that is difficult to flow by the flow air is included, the incombustible material is collected in the incombustible material extraction chute 17 along the inclined surface by inclining the hearth 12 in this manner. Can do.

FIG. 5 shows a fluidized bed furnace which is a second application example of the first embodiment. Fig.5 (a) is a top view which shows a hearth part, (b) is the Y'-Y 'sectional view taken on the line of (a).
This fluidized bed furnace has side walls 201 and 202 extending in parallel to the valley at the center of the hearth 12 and the bottom of the nonflammable material extraction chute located at the bottom in FIG. A groove-shaped incombustible material extraction opening 20 having an inclined surface 16 that is inclined downwardly toward one side in a tapered manner toward 17 is provided. A groove-shaped incombustible material extraction opening 20 is formed in the center of the hearth 12, and an inclined portion 16 that is inclined downward from one end to the other end of the opening 20 is provided. An incombustible material extraction chute 17 is connected to the other end side. And like the said Example 1, the some auxiliary nozzle 18 is opposingly arranged by the side wall of the said incombustible material extraction opening 20. FIG. In these application examples, a difference in superficial velocity is provided in the same manner as in the first embodiment, and the auxiliary nozzle 18 is configured to eject auxiliary air downward.

6A and 6B are diagrams showing a fluidized bed furnace according to Embodiment 2 of the present invention. FIG. 6A is a plan view showing a horizontal hearth part, and FIG. 6B is a line X′-X ′ in FIG. It is sectional drawing, (c) is a top view which shows the hearth part of an inclined shape, (d) is X "-X" sectional view taken on the line of (c).
FIG. 7 is a perspective view showing the entire configuration of the fluidized bed furnace showing the horizontal hearth part of (a) and (b) shown in FIG.
A fluidized bed furnace 10 according to the second embodiment includes a square or cylindrical (not shown) furnace main body 11 as shown in FIG. 7 and a horizontal hearth formed at the bottom of the furnace main body 11. And an air dispersion plate disposed horizontally on the hearth portion 12 at a position facing the inside of the furnace, and a wind box for temporarily retaining the flowing air below the air dispersion plate 14 is provided. Although the hearth 12 in the present embodiment is preferably horizontal, it can also be inclined. The wind box 14 is divided into a plurality of partitions by vertical partition plates 15a and 15b.

As shown in FIGS. 6A, 6B, 6C, and 6D, the air dispersion plate is provided with a plurality of air introduction nozzles 13 for flow. From the flow air introduction nozzle 13, flow air for flowing the flow medium and the incineration material introduced above the air dispersion plate is ejected. The flow rate of the flowing air is determined by the flow rate of air introduced into the wind box 14.
Further, as shown in FIGS. 6A and 6C, the center of the hearth 12 is formed by a circular opening 20 formed by a circular peripheral wall 203 extending downward as a side wall or a rectangular side wall extending downward. A rectangular opening (not shown) is formed, and an incombustible material extraction chute 19 is connected downward from the opening 20. A plurality of auxiliary nozzles 18 are arranged to face each other at a predetermined interval on the upper end side of the peripheral wall 203 forming the circular opening 20. The auxiliary air introduced from the auxiliary nozzle 18 is controlled in flow rate by a single air flow rate control mechanism.
The auxiliary nozzle 18 has a structure in which auxiliary air is ejected at an angle downward from the horizontal direction, similar to the structure described in FIG. 3 of the first embodiment.

Further, in the second embodiment, the flow air and the auxiliary air are set so that the superficial velocity in the circular opening 20 above the incombustible material extraction chute 19 is smaller than the superficial velocity above the hearth 12. The introduction flow rate is controlled respectively. The non-combustible material can be collected in the non-combustible material extraction chute 19 by the difference in the superficial velocity and the specific gravity difference between the fluid medium and the non-combustible material. Further, the downward auxiliary air ejected from the auxiliary nozzle 18 forms a downward flow of the fluid medium in the circular opening 20, and the downward flow promotes the discharge of incombustibles.
In addition, it is preferable that the jet jet length of the auxiliary air introduced from the plurality of auxiliary nozzles 18 is adjusted to form a jet jet non-reaching region in the central portion in the circular opening 20. Even if the incombustible material is relatively small, the incombustible material can be reliably discharged from the region where the jet jet has not reached without being blocked by the auxiliary air.

It is a figure which shows the fluidized-bed furnace which concerns on Example 1 of this invention, (a) is a top view which shows a hearth part, (b) is XX sectional drawing of (a), (c) is It is XX sectional drawing which concerns on another form of (b), (d) is the YY sectional view taken on the line of (a). FIG. 2 is a perspective view showing the entire configuration of the fluidized bed furnace shown in FIG. 1 and having a horizontal bed. It is a side view which shows an example of the auxiliary nozzle applied to this invention. It is a 1st application example of the fluidized bed furnace shown in Drawing 1, and is a perspective view showing the whole fluidized bed furnace composition in the case of having an inclined bed. FIG. 3 is a second application example of the fluidized bed furnace shown in FIG. 1, (a) is a plan view showing the hearth part, and (b) is a sectional view taken along the line Y′-Y ′ of (a). It is a figure which shows the fluidized-bed furnace which concerns on Example 2 of this invention, (a) is a top view which shows a horizontal-shaped hearth part, (b) is X'-X 'sectional view taken on the line of (a). (C) is a top view which shows the inclined hearth part, (d) is X "-X" sectional view taken on the line of (c). It is a perspective view which shows the whole structure of the fluidized bed furnace shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Fluidized bed furnace 11 Furnace main body 12 Furnace part 13 Flowing air introduction nozzle 14 Wind box 15, 15a, 15b Partition plate 16 Inclined part 17 Incombustible discharge outlet 18, 18a, 18b Auxiliary nozzle 18c Taper part 18d Ejection hole 19 Incombustible Material extraction chute 20 Incombustible material extraction opening 201, 202, 203 Side wall (peripheral wall)

Claims (5)

A fluidized bed furnace for performing a combustion treatment while mixing and flowing a fluidized medium and an incinerated material mixed with an incombustible material having a specific gravity greater than that of the fluidized medium, and an aeration means for introducing fluidizing air into the hearth part In a fluidized bed furnace in which an incombustible material extraction opening is formed at the center of the hearth part, and an incombustible material extraction chute is connected to the lower part of the opening,
A plurality of auxiliary nozzles are disposed opposite to the side wall of the opening, and the auxiliary nozzles eject auxiliary air at an angle downward from the horizontal direction.
A fluidized bed furnace that promotes discharge of the incombustible material guided to the opening by the discharge of the auxiliary air toward the incombustible material extraction chute.   The opening is a circular opening formed by a circular peripheral wall extending downward as a side wall, and a plurality of auxiliary nozzles are arranged opposite to the upper end side of the opening on the hearth side of the peripheral wall, and the auxiliary nozzles are angled downward from the horizontal direction. The fluidized bed furnace according to claim 1, which has a structure for ejecting auxiliary air. The opening is a groove-shaped incombustible material extraction opening provided at the center of the hearth part, and the bottom surface of the opening is an inclined part inclined downward from at least one opening end part, Incombustible material extraction chute is connected,
An auxiliary nozzle is disposed opposite to both side walls facing and extending in parallel with the groove-shaped incombustible material extraction opening, and the auxiliary nozzle ejects auxiliary air at an angle downward from the horizontal direction. The fluidized bed furnace according to 1.   The hearth on both sides of the side wall constituting the opening or around the side wall is formed of a horizontal floor, and the flow rate is such that the superficial velocity above the incombustible material extraction chute is smaller than the superficial velocity above the horizontal floor. The introduction flow rate of air and the auxiliary air is controlled, respectively, and the incombustible material is collected in the incombustible material extraction chute due to a difference in specific gravity between the fluid medium and the incombustible material. 4. The fluidized bed furnace according to any one of 3. The plurality of auxiliary nozzles are provided in a direction substantially perpendicular to the side wall of the incombustible material extraction opening, and the auxiliary nozzle is inclined at an angle downward from the horizontal direction from an ejection hole that is drilled obliquely downward at the tip of the auxiliary nozzle. The fluidized bed furnace according to any one of claims 1 to 4, wherein auxiliary air is jetted out.

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