JP2000088225A - Large fluidized bed incinerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the difference in layer heights by reducing the changing quantity in hearth heights even when the slope of a hearth part is increased in order to obtain a large hearth area, to reduce the blower power of fluidizing air, and to incinerate a large amount of wastes containing a large quantity of iron wire or the like. SOLUTION: The incinerator comprises a central hearth part 13 and a central blast box 17 disposed on central positions of a furnace main body 11, an annular hearth part 14 and an annular blast box 18 disposed on circumferences of the central hearth part 13 via an annular extracting passage 15, a funnel shape layer matter extracting cylinder 21 extended from the inner circumferential part of the annular hearth part 14 so as to form the annular extracting passage 15 and connected to one extracting opening 22, and embedded dispersion nozzles 16A, 16B flowing out dispersed air of the blast boxes 17, 18 to the central hearth part 13 and the annular hearth part 14. Each inclination θ of the central hearth part 13 and the annular hearth part 14 is set in a range of 25 deg. to 45 deg., respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a large-sized fluidized bed incinerator for a large amount of waste including wire, wire and the like.

[0002]

2. Description of the Related Art For example, lager cake, pulper cake, screw cake, and the like discharged in the process of reprocessing waste paper and corrugated cardboard contain a large amount of iron wire such as wire, wire, and large and small stapler needles. In the open bed type without a hearth, the bed material descends slowly at the lower part of the dispersion pipe that blows fluidized air, and hardly descends especially at the walls and corners. Are entangled and accumulate, making it difficult to discharge. Further, even in a closed bed type having a hearth, these iron wires are caught and deposited in the furnace on the dispersing air nozzles on the hearth, and it is easy to discharge from the hearth.

[0003] As a countermeasure, for example, in the case of a closed bed type, the surface of the hearth is flattened and the gradient thereof is ensured to some extent, so that the retention of incombustible substances can be prevented.

[0004]

By the way, the amount of waste discharged in these reprocessing steps is large, and when the hearth area is increased to process a large amount of waste, the gradient of the hearth is, for example, increased. Assuming that the angle of repose is 30 °, which is close to the angle of repose of the layer material, for example, in a large furnace having a diameter of 4.5 m, the height difference of the hearth is 1.
5 m to 2.0 m, the difference in bed height of the fluidized bed is large, and the fluidized state deteriorates. In order to improve this, excessive blower power of fluidizing air is required, and there is a problem that running cost is significantly increased.

The present invention solves the above-mentioned problems, and can reduce the height difference of the hearth even if the hearth area is widened, reduce the height difference of the fluidized bed, and reduce the blower power of the fluidized air. It is an object of the present invention to provide a large fluidized bed incinerator which can ensure good fluidity and can incinerate a large amount of waste even if the waste contains a large amount of iron wire.

[0006]

In order to achieve the above object, the present invention provides a central hearth section inclined at a predetermined gradient from a central position of a furnace main body and a central wind box arranged below the central hearth section.
An annular hearth portion disposed around the central hearth portion through an annular extraction passage and inclined from the outer peripheral side to an inner peripheral portion at a predetermined gradient, and an annular wind box disposed below the annular hearth portion; A funnel-shaped layered material extraction cylinder that extends downward from the inner peripheral portion of the portion and concentrates an annular extraction passage formed on the outer periphery of the central wind box at the center position of the lower body to form one extraction port; An embedded dispersion nozzle that is provided in the central hearth and the annular hearth to eject fluidized air from the central wind box and the annular wind box into the furnace main body; and the central hearth and the annular hearth. The inclination of each part is set in the range of 25 ° to 45 °.

[0007] According to the above configuration, by making the hearth circular, the incombustibles can be distributed and landed almost uniformly by the agitating action of the fluidized bed, and the incombustibles can be uniformly discharged over the entire circumferential direction. Can be. In addition, even if the hearth area is widened and the hearth portion has a gradient in the range of 25 ° to 45 °, the central hearth portion and the annular shape are formed inside and outside the annular extraction passage for extracting the layer material. Since it is formed separately from the hearth, the difference in the height of the hearth can be reduced and the change in the height of the fluidized bed can be reduced. Can be done. Here, the gradient of the hearth is 25
The angle of repose of the layer material is about 30
°, when the amount of non-combustibles is small, the non-combustibles can be sufficiently moved and lowered by adding swinging on the floor by the jet of the dispersion nozzle at 25 ° to 30 °, and 30 ° to 45 °.
By setting the angle to °, even in the case of iron wires which contain a large amount of incombustible substances and are particularly likely to stay, the descent action by gravity works sufficiently, and it is possible to discharge without staying. Further, since the embedded dispersing nozzle is provided in the hearth portion, slippage of incombustibles can be improved and stagnation can be eliminated, and even incinerators such as iron wires can be reliably incinerated. In addition, since the annular extraction passage is concentrated at one extraction port, the layer material extraction device can be simplified.

According to a second aspect of the present invention, the sectional area of the annular extraction passage having the above-mentioned structure is set to 20% or less of the sectional area in the furnace main body. According to the above configuration, by reducing the opening area of the annular extraction passage to 20% or less, when the same amount of the layer material is fed, the cross-sectional area is reduced, thereby increasing the descending speed of the layer material. Thus, the layer material can be discharged while preventing entanglement and stagnation of incombustibles.

Further, according to a third aspect of the present invention, there is provided a center extraction passage formed at a center position at the bottom of the furnace main body, an inner annular hearth formed around the center extraction passage with a predetermined slope and a chevron-shaped cross section, and the like. An inner annular wind box disposed at a lower portion, and an outer annular hearth portion which is disposed around the inner annular hearth portion through an annular extraction passage and is inclined from an outer peripheral side to an inner peripheral portion at a predetermined gradient and a lower portion thereof And an annular extraction passage extending downwardly from the inner peripheral portion of the outer annular hearth portion and formed on the outer periphery of the inner annular wind box and being concentrated at the central extraction passage at a lower portion. A funnel-shaped layer material extraction cylinder forming two extraction ports, and embedding provided in the inner annular hearth and the outer annular hearth to allow fluidized air to be ejected from the central wind box and the annular wind box into the furnace body. A dispersing nozzle, and the inner annular hearth and The slope of the outer annular hearth unit each 25
The angle is set in the range of ° to 45 °.

According to the above construction, in addition to the function and effect of the first aspect, the inner annular hearth section is formed in a mountain-shaped cross section by the center extraction passage, so that the hearth area can be increased without increasing the layer height. Can be wider.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Here, an embodiment of a large fluidized bed incinerator according to the present invention will be described with reference to FIGS.

This fluidized bed incinerator is a closed bed type having a large hearth area capable of incinerating a large amount of waste containing a large amount of iron wire (non-combustible material) such as a wire, a wire, and a large and small stapler needle. In large furnaces, the gradient of the hearth section described later is set relatively large, and protrusions such as nozzles are eliminated to prevent stagnation of incombustibles, and to increase the hearth area, multiple hearth sections are used. It is provided.

As shown in FIG. 1, in an incinerator 1, a discharged layer material M is fed into a vibrating sieve device 3 which is a layer material separating device by a discharge screw feeder 2 connected to a bottom portion, and is a fluid medium. It is configured to separate the fluidized medium into sand and incombustibles, and to circulate the fluidized medium to the incinerator 1 again. The vibrating sieve device 3 has a large slope of the sieve 3a and a large cross-sectional area of the incombustible discharge port 3b in consideration of prevention of catching and accumulation of incombustible materials such as iron wire.

As shown in FIG. 2, the incinerator 1 has a
Numeral 1 is a cylindrical shape having an upper portion formed on a large-diameter peripheral wall 11b and a lower portion formed on a small-diameter peripheral wall 11c via an inclined side wall 11a having a narrowed lower portion.
Is pierced. At the bottom of the furnace main body 11, a central hearth section 13 formed in a conical shape with a predetermined gradient θ from the center position of the furnace main body 1, and is disposed around the center hearth section 13 through an annular extraction passage 15. An annular hearth portion 14 inclined at a predetermined gradient θ from the outer peripheral side to the inner peripheral portion is provided. These central hearth 13 and annular hearth 14 have
A plurality of dispersing nozzles 16A and 16B are protruded at predetermined intervals through the floor plate, and the dispersing nozzles 16A and 16B are embedded with a refractory material filled on the floor plate to expose nozzle openings formed on upper side surfaces. It is configured to be embedded.

Here, a large incinerator is a circular hearth having a diameter of 4.5 m or more. For example, when the inner diameter D of the furnace body 11 is equal to or greater than 4.5 m and the inner diameter D is 4.5 m, the inner diameter d of the annular hearth portion 14 is formed to be = D-2 (m). The gradient θ of the central hearth 13 and the annular hearth 14
= 25 ° to 45 °, and the cross-sectional area of the annular extraction passage 15 is 20% or less of the floor area of the furnace main body 11, which is smaller than that of the open bed type.

Here, the gradient θ of the hearths 13 and 14 =
The reason why the angle is set to 25 ° to 45 ° is that the angle of repose of the layer material is about 30 °, and when there is little non-combustible material, the dispersion nozzles 16A, 16
This is because the non-combustible material can be sufficiently moved and lowered by adding the swing on the floor surface by the jet of B. On the other hand, in the case of iron wires which contain a large amount of non-combustible material and are particularly likely to stay there, 30
This is because by setting the angle to 45 to 45 °, the descent action by the gravity works sufficiently.

At the lower part of the central hearth 13, a cylindrical portion 17a is provided.
And a central wind box 17 comprising an inverted conical portion 17b below the central wind box 17 and supplies fluidized air from the central wind box 17 to the dispersion nozzle 16A. An annular wind box 18 having a trapezoidal cross section in which the annular hearth 14 is a hypotenuse is disposed below the annular hearth 14, and supplies fluidized air from the annular wind box 18 to the dispersion nozzle 16B. An annular extraction passage 15 is formed to extend downward from the inner peripheral portion of the annular wind box 18 in a funnel shape, and is formed on the outer periphery of the center wind box 17 to be concentrated at the center position of the furnace main body 11 so that one extraction port 22 is formed. A funnel-shaped layer material extraction cylinder 21 to be formed is provided. That is, the annular wind box 18 and the layer material extraction cylinder 2
The center wind box 17 is arranged in a core shape through the annular extraction passage 15 in the space defined by the center box 1.

An air supply duct 23 is connected to one end of the annular wind box 18.
An intermediate air duct 24 is connected to the cylindrical portion 17a of the central wind box 17 via the annular extraction passage 15 at every 0 °,
Fluidized air supplied from the air supply duct 23 to the annular wind box 18 is supplied to the central wind box 17 via the intermediate air duct 24. This intermediate air duct 24
In order to minimize friction with the layer material M extracted in the annular extraction passage 15, as shown in FIG. 4, the lower portion is formed in a semicircular shape 24a and the upper portion is formed in a cross section of a chevron 24b having a large inclination angle β. Have been.

A dispersion nozzle 16A is provided at the bottom of the central wind box 17.
A plurality of layer material discharge pipes 25A for discharging the layer material M that has flowed into the central wind box 17 are connected through the annular withdrawal passage 15, and the bottom of the annular wind box 18 is also connected to the bottom of the annular wind box 18 from the dispersion nozzle 16B. A plurality of layer material discharge pipes 25 </ b> B for discharging the layer material M flowing into the inside 18 are connected. 26A is the central wind box 1
Reference numeral 26B denotes an inspection manhole provided at 7, and reference numeral 26B denotes an inspection manhole provided at the layer material extraction cylinder 21.

In the above configuration, the fluidized air supplied from the air supply duct 23 to the annular wind box 18 is jetted from the dispersing nozzle 16B, and also from the annular wind box 18 via the intermediate air duct 24 to the central wind box 17. The bed material M is fluidized by being sprayed from the dispersion nozzle 16A, and the waste material input from the waste inlet 12 is heated and burned by the high-temperature bed material M. At this time, non-combustible substances such as iron wires entrained in the fluidized bed material M are removed from the embedded dispersion nozzle 16.
A, 16B, the central hearth 13 and the annular hearth 14
It slides down smoothly along the slope, and the annular extraction passage 1
It is discharged to 5. At this time, since the cross-sectional area of the annular extraction passage 15 is as small as 20% or less of the hearth area, the flow speed of the layer material M is high, and the flow of incombustibles is promoted, so that stagnation and accumulation can be prevented. This also promotes the flow of the layer material M at the corner.

Then, the discharge port 2 from the annular discharge passage 15
2 is discharged from the discharge screw feeder 2 to the vibrating sieve device 3 and the layer material M is separated into sand as a fluid medium and incombustible substances such as ash and iron wire. 1
Is returned to. Ash and incombustibles are separated by a metal separation device (not shown) and reused or landfilled.

According to the above-described embodiment, an annular extraction passage 15 is formed at the bottom of the cylindrical furnace main body to separate the hearth into the central hearth 13 and the annular hearth 14, and the annular extraction is performed. Since a gradient is provided on the lower side of the passage 15 side, the hearth portions 13, 1
Even if the gradient θ of 4 is set in the range of 25 ° to 45 °, the height difference between the hearths of the hearth portions 13 and 14 can be reduced. Further, the circular hearth portions 13 and 14 have a uniform length in the gradient direction, and the height difference of the hearth is partially large, and there is almost no high layer portion which is likely to partially stay.

Therefore, the gradient θ of the hearths 13 and 14 is made sufficiently large such that the incombustible material has a good slippage of 25 ° to 45 °,
Further, even if the hearth area is increased, the difference in bed height of the fluidized bed can be reduced. Thereby, sufficient fluidization can be obtained even if the blower power of the fluidizing air is small, and even in a large incinerator having a large hearth area, the gradient of the hearth portions 13 and 14 can be sufficiently obtained, and the sedimentation can be achieved. Wastes containing a large amount of incombustible materials such as iron wire can be treated in large quantities and well.

Here, by setting the gradient θ of the hearths 13 and 14 in the range of 25 ° to 45 °, when the angle of repose of the layer material is about 30 ° and the amount of incombustibles is small, 25 ° ° to 30
In addition, swinging on the floor is added by the jets of the dispersion nozzles 16A and 16B at an angle of .degree., So that the incombustibles can be sufficiently moved and lowered, and the gradient .theta.
By setting the angle to °, even in the case of iron wires which contain a large amount of incombustible substances and are particularly likely to stay, the descent action by gravity works sufficiently, and it is possible to discharge without staying.

Further, since the embedding type dispersion nozzles 16A and 16B are arranged in the hearths 13 and 14, no incombustible substances are entangled. Further, since the area of the inlet opening of the annular extraction passage 15 is set to be as small as 20% or less of the entire hearth area and the flow speed of the bed material M is increased, the flow of incombustibles is promoted. Stagnation and accumulation are effectively prevented.

FIG. 5 shows another embodiment of a large-sized fluidized bed incinerator. The same members as those in the previous embodiment are denoted by the same reference numerals, and the description thereof will be omitted. An inner annular hearth portion 32 in which a center extraction passage 31 is formed at the bottom center position of the furnace body 11
Are arranged, and an outer annular hearth portion 14 is arranged on an outer peripheral portion of the inner annular hearth portion 32 via an annular extraction passage 15. Then, an inner annular wind box 33 is arranged at the bottom of the inner annular hearth 32, and an outer annular wind box 18 is arranged at the bottom of the outer annular hearth 14. This inner ring hearth 32
Are formed in a chevron-shaped cross section having the top at the center of the width in the radial direction. The annular extraction passage 15 formed by the layer material extraction cylinder 21 is joined to a central extraction passage 31 at a lower portion and connected to one extraction port 22.

According to the fluidized bed incinerator 30, a central extraction passage 31 is formed in the center of the incinerator 1 so that the central hearth is formed in an annular shape and the inner annular hearth 32 is formed. By providing the inner annular hearth portion 32 with a mountain-shaped cross section, the outer diameter thereof can be doubled or more without increasing the amount of displacement in the height direction while maintaining the same gradient. The floor area can be increased.

[0028]

As described above, according to the first aspect of the present invention, by making the hearth circular, incombustibles can be distributed and landed almost uniformly by the agitating action of the fluidized bed. Incombustibles can be uniformly discharged over the circumferential direction.
In addition, even if the hearth area is widened and the hearth portion has a gradient in the range of 25 ° to 45 °, the central hearth portion and the annular shape are formed inside and outside the annular extraction passage for extracting the layer material. Since it is formed separately from the hearth, the difference in the height of the hearth can be reduced and the change in the height of the fluidized bed can be reduced. Can be done.
Here, by setting the gradient of the hearth in the range of 25 ° to 45 °, the angle of repose of the layer material is about 30 °, and when there is little incombustible material, the angle of the dispersion nozzle is 25 ° to 30 °. By adding swinging on the floor by the jet, the incombustibles can be moved and lowered sufficiently by setting the angle between 30 ° and 45 °. The descent action by gravity works, and it can be discharged without stagnation. Further, since the embedded dispersing nozzle is provided in the hearth portion, slippage of incombustibles can be improved and stagnation can be eliminated, and even incinerators such as iron wires can be reliably incinerated. In addition, since the annular extraction passage is concentrated at one extraction port, the layer material extraction device can be simplified.

According to the second aspect of the present invention, by reducing the opening area of the annular extraction passage to 20% or less,
When the same amount of the layer material is fed, the lowering rate of the layer material is increased by reducing the cross-sectional area, whereby the layer material can be discharged while preventing entanglement and stagnation of incombustibles.

According to the third aspect of the present invention, in addition to the effect of the first aspect, the inner annular hearth portion is formed in a mountain-shaped cross section by the center extraction passage, so that the layer height is not increased. The hearth area can be made wider.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of a large-scale fluidized-bed incinerator according to the present invention.

FIG. 2 is an enlarged vertical sectional view of the incinerator.

FIG. 3 is a sectional view taken along the line AA shown in FIG. 2;

FIG. 4 is a cross-sectional view showing an intermediate air duct of the incinerator.

FIG. 5 is a configuration diagram showing an embodiment of a large-sized fluidized-bed incinerator according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Incinerator 11 Furnace main body 12 Waste inlet 13 Central hearth 14 Annular hearth (outer annular hearth) 15 Annular extraction passage 16A, 16B Dispersion nozzle 17 Center wind box 18 Annular wind box (Outer annular wind box) ) 21 layer extraction tube 22 extraction outlet 23 air supply duct 24 intermediate air duct 31 center extraction passage 32 inner annular hearth 33 inner annular wind box M layer material

Continuing from the front page (72) Inventor Seiichi Nakai 1-7-89 Minami Kohoku, Suminoe-ku, Osaka-shi, Osaka Inside Hitachi Zosen Corporation (72) Inventor Ken Matsui 1- 7-89 Minami-Kohoku, Suminoe-ku, Osaka-shi, Osaka No. F-term in Hitachi Zosen Corporation (reference) 3K064 AA18 AB03 AC01 AD08 AE04 AE16 AE20 BA05

Claims (3)

[Claims] 1. A central hearth section inclined at a predetermined gradient from a center position of a furnace main body and a central wind box disposed below the central hearth section, and are disposed around the central hearth section via an annular extraction passage. An annular hearth portion inclined at a predetermined gradient from the outer peripheral side to the inner peripheral portion and an annular wind box disposed below the annular hearth portion, and extending downward from the inner peripheral portion of the annular hearth portion to the outer periphery of the central wind box. A funnel-shaped layered material extraction cylinder that forms one extraction port by concentrating the formed annular extraction passage at the center position of the lower main body; a central wind box provided in the central hearth and the annular hearth And an embedded dispersion nozzle for jetting fluidized air from the annular wind box into the furnace main body, wherein the gradient of the central hearth and the annular hearth is 25, respectively.
A large fluidized bed incinerator characterized in that it is set in the range of ° to 45 °. 2. The large fluidized bed incinerator according to claim 1, wherein the cross-sectional area of the annular discharge passage is 20% or less of the cross-sectional area in the furnace main body. 3. A center extraction passage formed at the center of the bottom of the furnace main body, an inner annular hearth formed around the center extraction passage with a predetermined slope at an angled cross section, and an inner ring disposed at a lower portion thereof. A wind box, an outer annular hearth portion disposed around the inner annular hearth portion through an annular extraction passage, inclined from the outer peripheral side to the inner peripheral portion at a predetermined gradient, and an outer annular wind disposed below the outer annular hearth portion A box, and a funnel that extends downward from the inner peripheral portion of the outer annular hearth portion and forms an outlet through a central extracting passage formed at the lower portion of the annular extracting passage formed on the outer periphery of the inner annular wind box. A layered material extraction cylinder, and an embedded dispersion nozzle provided on the inner annular hearth and the outer annular hearth to eject fluidized air from the central wind box and the annular wind box into the furnace body. The gradient of the inner annular hearth and the outer annular hearth A large-sized fluidized-bed incinerator characterized by being set in the range of 25 ° to 45 °.