JPH09236227A - Fluidized bed type thermal reaction device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable ignited substances mixed with non-ignitable substances to be uniformly and completely ignited or gasified and further to enable the non-ignitable substances to be separated and discharged easily and smoothly. SOLUTION: A weak air dispersion device 2, a high air dispersion device 3 and a non-ignitable substance taking-out port 8 are arranged at the bottom part in a furnace. The high air dispersion device 3 can supply fluidized gas in such a way that an upward-directed flow of fluidized medium may be formed, provided with an inclination surface directed toward the non-ignitable substance taking-out port 8. The weak air dispersion device 2 is arranged adjacent to the high air dispersion device 3 and can supply fluidized gas in such a way that it may form a descending flow of the fluidized medium as a weak fluidized region 17. In addition, there is provided a descending inclination surface having a larger angle than that of the high air dispersion device 3 toward the non-ignitable substance taking-out port 8. The non-ignitable substance taking-out port 8 may blow out the fluidized gas to the inner surface of it, thereby a forming of the descending flow of the fluidized medium is promoted, an ignitable substance supplying port is arranged above the weak fluidized regions 17 and 22, the ignited substances 10 are dropped onto the weak fluidized region and merged into the descending flow.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluidized bed thermal reactor, and in particular, it uniformly burns or gasifies solid substances containing incombustible substances such as industrial waste, municipal solid waste, and coal,
In addition, the present invention relates to a fluidized bed thermal reactor capable of stably recovering thermal energy while smoothly discharging incombustibles. The fluidized bed thermal reactor includes such devices as a fluidized bed combustion furnace and a fluidized bed gasification furnace.

[0002]

2. Description of the Related Art With the economic development, the amount of general waste is 3 to 3 years each year.
It has increased by 4% and now reaches 50 million tons per year. Moreover, 82% of this is combustible, which is 7 in oil equivalent.
It is equivalent to 200,000 tons.

Further, the amount of industrial waste has been increasing, and plastics containing incombustible materials which were conventionally landfilled as unsuitable materials for combustion will inevitably be incinerated in order to reduce the burden on landfill sites. The amount of combustible industrial waste such as waste oil and waste plastic is about 17 million tons per year, and the calorific value is more than 3000 kcal / kg, so it is more suitable as fuel than waste.

However, since the properties and shapes of wastes are very diverse, and they are not constant, and indeterminately shaped incombustible substances are mixed, stable combustion and treatment are difficult, and general wastes It also prevented the effective use of industrial waste energy.

[0005]

In order to effectively use energy of general waste and industrial waste, various systems have been developed so far for the purpose of recovering thermal energy by incineration. Among them, a fluidized bed incinerator or a fluidized bed boiler is expected to be a system capable of uniformly burning solid substances including incombustible substances and stably recovering thermal energy while smoothly discharging incombustible substances. However, there are the following issues.

That is, in the circulating fluidized bed, since there is no clear dense fluidized bed, the size of the combustible material that can be accepted is small, and therefore fine crushing is required, and installation costs and operating costs of the crushing equipment are large. . Also,
Incombustibles are deposited on the hearth, but since there is no dense fluidized bed, it is difficult to seal the pressure when discharging incombustibles, and it is unsuitable for the treatment of wastes containing incombustibles of irregular shape.

On the other hand, in the bubbling fluidized bed, since the flow is only in the vertical direction, the incineration product is not sufficiently dispersed, and uniform and stable combustion is difficult. Further, incombustibles having a specific gravity larger than that of the fluidized medium are deposited in a wide range on the hearth, and as a result, it is difficult to discharge the incombustibles, which hinders the operation.

For this reason, recently, not a simple bubbling fluidized bed, but a method in which the fluidization speed is changed to generate a swirling flow in the dense fluidized bed to improve the mixing and dispersion of the incineration product and to perform stable combustion. Have been developed.

The present invention has been made in view of the above-mentioned circumstances, and makes it possible to uniformly and completely combust or gasify an incinerator mixed with an incombustible and at the same time, to separate and discharge the incombustible easily. It is an object of the present invention to provide a fluidized bed thermal reactor which can be smoothly operated.

[0010]

A fluidized bed thermal reactor of the present invention is a fluidized bed thermal reactor in which a combustible material containing an incombustible component is burned, each of which has a plurality of fluidizing gas supply holes. An air diffuser, a strong air diffuser, and an incombustibles outlet are arranged at the bottom of the furnace, and the strong air diffuser gives the fluidized medium a relatively large fluidization rate to form an upward flow of the fluidized medium. It is possible to supply the fluidizing gas and has an inclined surface toward the incombustibles outlet, and the weak diffuser is placed adjacent to the strong diffuser, and the fluidizing medium is supplied with a relatively low fluidizing speed. A fluidizing gas can be supplied so as to form a settling flow of the medium, and further, it has a descending inclined surface that has a larger angle toward the incombustibles outlet than the strong diffuser, and the incombustibles outlet is a weak diffuser. Is placed adjacent to, and the fluidizing gas is blown to the inner surface of the The incombustible outlet above the weak fluidizing region by the scan, so as to form a descending flow of the fluidized medium,
It is characterized in that a combustible material supply port is arranged above the weak fluidization area so that the combustible material falls into the weak fluidization area and is swallowed in the sedimentation flow.

Further, an inclined wall is arranged above the strong air diffuser to divert the fluidizing gas and fluid medium rising above the strong air diffuser to the central part of the furnace, and the strong air diffuser does not burn. It is characterized in that it is provided with an ascending sloping surface that rises as it moves away from the article take-out port, and that the fluidization speed increases sequentially as it goes away from the non-combustible matter take-out port.

The incombustibles outlet is arranged over the entire width of the furnace, and a fluidizing gas outlet is provided on the inner surface of the incombustibles outlet on the side wall of the furnace.

Further, the weak air diffuser and the strong air diffuser are arranged symmetrically with respect to the incombustibles outlet, and the furnace is cylindrical.

Further, the weak air diffuser and the strong air diffuser are arranged symmetrically with respect to the incombustibles outlet, and the furnace has a rectangular planar shape.

The incombustibles outlet has a rectangular planar shape, and the weak air diffuser and the strong air diffuser are symmetrical with respect to the four directions when viewed in plan with the incombustibles outlet as the center. And the furnace is cylindrical.

Further, the incombustibles outlet has a rectangular planar shape, and the weak air diffuser and the strong air diffuser are symmetrical with respect to the four directions when viewed in plan with the incombustibles outlet as the center. And the furnace has a rectangular planar shape.

Further, the incombustibles outlet is characterized in that the plane shape is circular and the furnace is cylindrical.

Further, the air diffuser is a blowing nozzle.

Further, the air diffuser is a diffuser plate.

As a result of the above-mentioned structure, a settling flow of the fluidizing medium is formed in the weak fluidizing region where the fluidizing velocity is small, and in the vicinity of the hearth of the fluidizing medium, the fluidizing medium is horizontally directed toward the portion where the fluidizing velocity is high. A moving stream of is formed. When the fluidized medium that has moved horizontally reaches the fluidized portion where the fluidization velocity is high, it turns to upflow this time. The upward flow is blocked by the upper sloping wall, turns horizontally again, and returns to the weak fluidization zone where the fluidization velocity is low, and the entire fluidized bed sinks in the weak fluidization zone, and the strong fluidization zone A swirling flow rises at.

For this reason, the injected combustion product undergoes thermal decomposition in the central settling flow moving layer, moves downward while performing partial combustion, and further burns while moving horizontally.
In the process, since the incombustibles contained in the combustibles have a larger specific gravity than the fluidized medium, they are gradually separated and moved downward by fluidization while moving from the settling flow to the horizontal flow, and at the outlet of the fluidized medium for discharging the incombustibles. It is discharged together with some fluid medium. In particular, the air diffuser provided on the inner surface of the incombustibles outlet has a sufficient amount of fluidizing gas to form a weak fluidization region above the incombustibles outlet, but is relatively violently fluidized near the air diffuser, The effect of accumulating incombustibles by the wind power selection is great.

On the other hand, after the majority of the incombustibles and a part of the fluidized medium are separated at the incombustibles outlet, the remaining fluidized medium containing the combustibles turns from a horizontal flow to an upward flow in the strong fluidization region, and then flows upward. In the flow, vigorous combustion is performed due to the oxidizing atmosphere and strong fluidization, and the unburned components are completely burned.

As described above, the fluidized bed forms a swirl flow as a whole, and the fluidized medium outlet for discharging incombustibles is provided before the settling flow moves to a horizontal flow in the swirl flow, so that incineration with incombustibles mixed therein is performed. It is possible to simultaneously and effectively separate and discharge incombustible substances from a product and perform uniform combustion.

[0024]

Embodiments of the present invention will be described below with reference to the accompanying drawings. In the present embodiment, a fluidized bed combustion furnace will be described as an example of the fluidized bed reactor.

FIG. 1 relates to a fluidized bed combustion furnace according to one embodiment of the present invention, and the schematic configuration and operation of the present invention will be described using this. The hearth of the fluidized bed furnace 1 is provided with a weak air diffuser 2 that provides a relatively low fluidization rate and a wind box 4 that supplies the weak air diffuser 2 with flowing air 14. And,
Adjacent to the weak air diffuser 2, there are provided a strong air diffuser 3 which gives a relatively high fluidization speed, and a wind box 5 which supplies flowing air 15 to the strong air diffuser 3. The wind boxes 4 and 5 are provided with fluidized air inlets 6 and 7, respectively.

The weak air diffuser 2 and the strong air diffuser 3 are also provided.
The hearth equipped with is inclined toward the incombustibles outlet 8, and the weak air diffuser 2 is inclined toward the incombustibles outlet at a steeper angle than the strong air diffuser 3. On the other hand, above the strong fluidization region 16 in which the fluidization speed is relatively increased by the air blown out from the strong air diffuser 3, a weak fluidization region that blocks the upward flow of the fluidizing medium and has a low fluidization speed. 1
A slanted wall 9 is provided so that the fluidized medium flows in a horizontal direction toward 7.

As described above, the weak fluidizing device 2 which gives a relatively small fluidizing speed and the strong air diffuser 3 which gives a relatively large fluidizing speed are provided with a strong fluidizing zone 16 and a weak fluidizing fluid in the fluidized bed. A chemical region 17 is formed.

As a result, a settling flow 18 is formed in the weak fluidization region 17 toward the lower part of the fluidized medium, and a horizontal flow 19 is formed in the vicinity of the hearth toward the strong fluidization region 16.
On the other hand, the upward flow 20 is formed in the strong fluidization region 16,
Since there is the inclined wall 9 above, the direction is changed to flow toward the weak fluidization region 17, and as a result, a continuous swirl flow that settles in the weak fluidization region 17 and rises in the strong fluidization region 16 is formed. .

On the other hand, the incinerated matter 10 to be charged is the settling stream 18
It is swallowed in the fluidized bed by riding on, is thermally decomposed by the high temperature fluid medium, and is partially burned. At that time, since the incombustible material 11 contained in the incinerated material 10 has a larger specific gravity than the fluidized medium, most of the incombustible material 11 gradually moves downward in the process of transition from the settling flow 18 to the horizontal flow 19. As a result, the fluidized medium in which the concentration of incombustibles becomes high goes toward the fluidized medium outlet 8 for incombustibles discharge along the steeply inclined surface of the weak air diffuser 2, and is discharged outside the furnace as an incombustibles discharge flow 13. .

On the other hand, at the fluid medium outlet 8 for discharging the incombustible material, after the majority of the incombustible material and a part of the fluid medium are separated, the remaining fluid medium becomes a horizontal flow 19 and reaches the strong fluidization zone 16.
There, it turns to the upward flow 20. In the upward flow 20, vigorous combustion is performed due to the oxidizing atmosphere and strong fluidization, and unburned components are completely burned.

As described above, the swirling flow facilitates the dispersive mixing of the incineration material inside the fluidized bed, and enables uniform and complete combustion. Moreover, since the incombustibles can be roughly sorted inside the fluidized bed to increase the concentration of the incombustibles in the fluidized medium, the amount of the fluidized medium taken out can be small, and as a result, the capacity of the incombustibles discharge system can be reduced.

Further, by providing an air diffuser 21 on the inner surface of the incombustibles outlet, a weak fluidization region 22 is formed above the incombustibles outlet to promote the formation of a settling flow of the fluid medium.
By fluidizing the vicinity of the fluid medium outlet, a larger amount of incombustibles can be settled inside the outlet 8, and the incombustibles can be discharged more easily and satisfactorily. Also, each air diffuser
It may be composed of any of a nozzle, an air diffuser, and a pipe.

FIG. 2 shows a plan view of the hearth portion as viewed downward from the section aa in FIG. An incombustibles outlet 8 is opened in the center of the hearth of the cylindrical fluidized bed furnace 1 over the entire width, and a weak diffuser 2 and a weak diffuser that symmetrically give a relatively small fluidization rate to the left and right of the incombustibles outlet 8. Adjacent to the air device 2 is provided a strong air diffuser 3 which provides a relatively high fluidization rate.

The weak air diffuser 2 and the strong air diffuser 3 are also provided.
Hearths provided with are inclined toward the incombustibles outlet 8, respectively, and the weak air diffuser 2 has a steeper angle than the strong air diffuser 3. Furthermore, an air diffuser 21 is provided on the inner surface of the incombustibles outlet 8, and a weak fluidization region 22 is formed above the incombustibles outlet to promote the formation of a settling flow of the fluidized medium.
By fluidizing the vicinity of the fluid medium outlet, a larger amount of incombustibles is settled inside the outlet 8, and the discharge of the incombustibles is kept good.

FIG. 3 shows another embodiment of the hearth part. A rectangular incombustibles outlet 8 is provided in the center of the hearth of the cylindrical fluidized bed furnace 1.
However, unlike the embodiment shown in FIG. 2, the weak air diffuser 2 that gives a relatively small fluidization velocity symmetrically in the left-right direction and the front-back direction, that is, the four directions, and the weak air diffuser 2 are opened.
Adjacent to is provided a strong air diffuser 3 which provides a relatively high fluidization rate.

The weak air diffuser 2 and the strong air diffuser 3 are also provided.
The hearths provided with are inclined toward the incombustibles outlet 8, respectively, and the weak diffuser 2 is at a steeper angle than the strong diffuser 3 and the inner surface of the incombustibles outlet 8 is Air diffuser 21
Is the same as the embodiment shown in FIG.

FIG. 4 shows another embodiment of the hearth portion. At the center of the hearth of the cylindrical fluidized bed furnace 1, a circular incombustibles outlet 8 is opened. A weak air diffuser 2 that provides a relatively low fluidization speed is arranged around the incombustibles outlet 8, and a relatively high fluidization speed is provided adjacent to the outer periphery of the weak air diffuser 2. A strong air diffuser 3 is provided.

On the other hand, the weak air diffuser 2 and the strong air diffuser 3
The hearths provided with are inclined toward the incombustibles outlet 8, respectively, and the weak air diffuser 2 has a steeper angle than the strong air diffuser 3 and is scattered on the inner surface of the incombustibles exhaust outlet 8. The point that the air device 21 is provided is common to the above-described embodiments.

FIG. 5 shows another embodiment of the hearth portion. 2 in that the fluidized bed furnace 1 has a rectangular planar shape.
Although different from the embodiment shown in FIG. 2, the incombustibles outlet 8 is opened in the center of the hearth over the entire width, and the weak air diffuser 2 which symmetrically extends in the left-right direction and which gives a relatively small fluidization velocity, Further, adjacent to the weak air diffuser 2, a strong air diffuser 3 which gives a relatively high fluidization speed is arranged.

The weak air diffuser 2 and the strong air diffuser 3 are also provided.
The hearths provided with are inclined toward the incombustibles outlet 8, respectively, and the weak air diffuser 2 is at a steeper angle than the strong air diffuser 3, or the inner surface of the incombustibles exhaust outlet 8 is The point that the air diffuser 21 is provided is common to the above-described embodiments.

The gist of the present invention is not limited to the above-described embodiments, and it goes without saying that various modified embodiments are possible.

[0042]

According to the present invention, while the fluidized bed forms a swirl flow as a whole, the incinerated matter is pyrolyzed and partially combusted along with the sedimentation flow, and horizontally moves while further burning near the hearth. In the process of moving, incombustibles having a larger specific gravity than the fluidized medium are wind-selected and gradually move downward. Inflammable substances with a small specific gravity gather upward. That is, the horizontal flow medium is a two-layer flow in which the lower side has a high concentration of incombustibles and the upper side has a high concentration of combustible substances.

Therefore, at the stage of transition from the settling flow to the horizontal flow by riding the swirl flow, the fluid medium having a high concentration of incombustibles is preferentially discharged, and only the combustible substance is sent to the strongly fluidized portion to perform complete combustion. It will be possible.

The weak air diffuser and the strong air diffuser, which are the hearth parts, are provided with inclined surfaces toward the incombustibles outlet, and in particular, the weak air diffuser adjacent to the incombustibles outlet has a large descending inclination. Since the surface is provided, incombustibles can be easily and smoothly discharged.

Further, an air diffuser is provided on the inner surface of the incombustible material outlet to form a weak fluidization region above the incombustible material outlet to promote the formation of a settling flow of the fluidized medium and to fluidize the vicinity of the fluidized medium outlet. By doing so, a larger amount of the incombustibles can be accumulated and settled inside the outlet, and the incombustibles can be discharged more easily and satisfactorily. That is, it is possible to uniformly and completely burn an incinerated material mixed with an incombustible material, and at the same time, separate and discharge an incombustible material easily and smoothly.

Although the fluidized bed combustion furnace has been described in the above description of the embodiments, the fluidized bed gasification furnace may be constructed by the same configuration as shown in FIGS. 1 to 5.

[Brief description of drawings]

FIG. 1 is an explanatory view of a fluidized bed combustion furnace which is an embodiment of a fluidized bed thermal reactor according to the present invention.

FIG. 2 is a plan view of a hearth portion viewed from the aa cross section of FIG.

FIG. 3 is a plan view of a hearth portion of another embodiment.

FIG. 4 is a plan view of a hearth portion of still another embodiment.

FIG. 5 is a plan view of a hearth portion of still another embodiment.

[Explanation of symbols]

 1 Fluidized Bed Combustion Furnace 2 Weak Air Diffuser 3 Strong Diffuser 8 Unburnt Material Outlet 9 Inclined Wall 10 Incinerated Material 16 Strong Fluidization Area 17,22 Weak Fluidization Area 18 Settling Flow 19 Horizontal Flow 20 Upflow

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Takahiro Oshita 11-1 Haneda Asahimachi, Ota-ku, Tokyo Inside Ebara Corporation

Claims (10)

[Claims] 1. A fluidized bed thermal reactor in which a combustible material containing incombustibles is burned, each of which includes a plurality of fluidizing gas supply holes, a weak air diffuser, a strong air diffuser, and an incombustible material outlet. Are placed at the bottom of the furnace, and the strong air diffuser can supply the fluidizing gas so as to give a relatively large fluidizing velocity to the fluidizing medium and form an upward flow of the fluidizing medium. A weak aeration device is provided adjacent to the strong aeration device and has a sloping surface facing toward it, and supplies the fluidizing gas so as to give a relatively low fluidization velocity to the fluidizing medium to form a settling flow of the fluidizing medium. It is possible to further provide a descending inclined surface that has a larger angle toward the incombustibles outlet than the strong diffuser, and the incombustibles outlet is arranged adjacent to the weak diffuser, and the fluidizing gas is attached to the inner surface of the incombustibles outlet. Blow-off, weak fluidization area above the incombustibles outlet by the fluidizing gas Then, a settling flow of the fluidized medium is formed, and a combustible material supply port is arranged above the weak fluidization zone to drop the combustible material into the weak fluidization zone and swallow it into the sedimentation flow. A fluidized bed thermal reactor characterized by the above. 2. An inclined wall is disposed above the strong air diffuser to divert the fluidizing gas and the fluid medium rising above the strong air diffuser to the central part of the furnace, and the strong air diffuser is non-combustible. The fluidized bed thermal reaction apparatus according to claim 1, wherein the fluidized bed thermal reactor has an ascending sloping surface that rises as it moves away from the material take-out port, and has a fluidization speed that gradually increases as it goes away from the non-combustible material take-out port. 3. The incombustibles outlet is arranged over the entire width of the furnace, and a fluidizing gas outlet is provided on the inner surface of the incombustibles outlet on the side wall of the furnace.
A fluidized bed thermal reactor as described. 4. The weak air diffuser and the strong air diffuser are arranged symmetrically with respect to the incombustibles outlet, and the furnace has a cylindrical shape. A fluidized bed thermal reactor according to claim 1. 5. The weak air diffuser and the strong air diffuser are symmetrically arranged around the incombustibles outlet, and the furnace has a rectangular planar shape. The fluidized bed thermal reactor according to claim 1. 6. The incombustibles outlet has a rectangular planar shape, and the weak air diffuser and the strong air diffuser are symmetrical with respect to the four directions when viewed in plan with the incombustibles outlet as a center. 4. The fluidized bed thermal reactor according to any one of claims 1 to 3, characterized in that it is arranged in the chamber and the furnace is cylindrical. 7. The incombustibles outlet has a rectangular planar shape, and the weak air diffuser and the strong air diffuser are symmetrical in four directions when viewed in plan with the incombustibles outlet as a center. 4. The fluidized bed thermal reactor according to any one of claims 1 to 3, characterized in that the furnace has a rectangular planar shape. 8. The fluidized bed thermal reactor according to claim 1, wherein the incombustibles outlet has a circular planar shape and the furnace has a cylindrical shape. 9. The fluidized bed thermal reactor according to claim 1, wherein the air diffuser is a blowing nozzle. 10. The fluidized bed thermal reactor according to claim 1, wherein the air diffuser is an air diffuser.