JPH11132427A - Incinerator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve difficulties that when a swirling flow is formed in a conventional incinerator, a descending flow is formed on the basis of the swirling flow to promote more gasification of an article to be combusted that it needs and hence produce a big volume of gas to be combusted whereby incomplete combustion becomes liable to be produced. SOLUTION: An incinerator is adapted such that it includes a combustion furnace 30 in which an article 80 to be combusted is combusted while supplying combustion air. In the incinerator, there are provided in the combustion furnace 30 a swirling flow formation nozzle 35 disposed above a region where gasification is caused such that combustion gas produced owing to gasification of the article 80 is turned, and an air curtain formation nozzle 36 disposed between a region where it serves to weaken a descending flow formed by the swirling flow 35 and gasification is produced, and a region where the swirling flow formation nozzle 35 is disposed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an incinerator.

[0002]

2. Description of the Related Art In general, when incinerating general waste such as municipal waste and industrial waste such as waste plastic, incompletely combusted components such as CO and unburned hydrocarbons are discharged from the viewpoint of pollution prevention. It is required that the fuel be completely burned so as not to do so. In particular, in recent years, there has been a concern that dioxin, which is a harmful substance, will be generated with incineration. In this case, it has been pointed out that there is a positive correlation between the amount of dioxin generated and the CO concentration, and from such a viewpoint, incinerators are strongly required to achieve complete combustion. .

[0003] In order to enhance the mixing effect in a combustion furnace so as to bring about complete combustion, a technique for generating a swirling flow in the combustion furnace is known.

A technique for generating a swirling flow in a combustion furnace is disclosed in Japanese Patent Laid-Open No. 52-61365. FIG.
11 is a diagram described in the above-mentioned publication, in which the incinerator 10 is configured to include a combustion furnace 11, and the combustion furnace 11 is provided with a nozzle unit 12.

The nozzle section 12 has a first nozzle 13 and a second nozzle 14 arranged in a staggered pattern.
The first nozzle 13 is for ejecting an air flow 13a directed tangentially to the left with respect to the center O of the combustion furnace 11, and
The lower one has a larger diameter. Second nozzle 14
Is for injecting the air flow 14a directed in the tangential direction on the right side with respect to the center O of the combustion furnace 11, and the lower one has a larger diameter. However, the diameter of the second nozzle 14 is smaller than the diameter of the first nozzle 13 located in the vicinity.

[0006] In the incinerator 10 having the above configuration,
The first nozzle 13 forms a swirling flow that is larger toward the lower side of the combustion furnace 11. Similarly, the swirling flow is formed by the second nozzle 14 toward the lower side of the combustion furnace 11. In this case, the swirling flow by the second nozzle 14 is
It acts to weaken the swirling flow by the nozzle 13. Therefore, the combustion gas generated in the lower part of the combustion furnace 11 is
Due to the swirling flow, the residence time in the furnace increases.

[0007]

However, in the combustion furnace 11 of the incinerator 10, since a swirl flow is generated, the swirl flow generates a downward flow reaching the lower part of the combustion furnace 11. Because of this downward flow,
Gasification of the incinerated material is promoted more than necessary, a large amount of gas to be burned is generated, the mixing of gas and oxygen cannot keep up, and unburned components such as CO are generated. Was. In order to avoid this problem, if an attempt is made to supply enough oxygen for the large amount of generated gas, the amount of oxygen must be greatly increased. As a result, the internal temperature decreases, and unburned components also occur.

The present invention has been made in view of the above circumstances. Even when a swirl flow is formed in a combustion furnace, the down flow accompanying the swirl flow is restricted to thereby gasify the down flow. It is an object of the present invention to provide an incinerator capable of suppressing the influence on the combustion furnace, that is, controlling gasification to improve the combustion efficiency of the combustion furnace.

[0009]

The incinerator according to claim 1 is provided with a combustion furnace for burning an incineration object while supplying combustion air, wherein the combustion furnace includes the combustion furnace. A swirling flow forming nozzle disposed above a region where the gasification occurs so as to swirl the combustion gas generated by gasification of the incinerated material; and a gasification device that acts to weaken a downward flow generated by the swirling flow. Characterized in that a downward flow suppressing means is provided between a region where the occurrence of the flow occurs and a region where the swirling flow forming nozzle is disposed. In the incinerator according to the second aspect, in the incinerator according to the first aspect, the downflow suppressing means is formed in a vertically flat shape so as to form an air curtain extending in the vertical direction. It is characterized in that an air curtain forming nozzle is provided. In the incinerator according to claim 3, in the incinerator according to claim 2,
The air curtain forming nozzles are arranged at regular intervals along the inner surface of the wall of the combustion furnace and toward the center of the combustion furnace. In the incinerator according to claim 4, in the incinerator according to any one of claims 1 to 3, in order to supply the combustion air,
The combustion furnace is provided with a combustion air supply nozzle, and the swirl flow forming nozzle blows out air at a higher speed than the combustion air supply nozzle. In the incinerator according to claim 5, in the incinerator according to any one of claims 1 to 4, an inclined surface that descends from the outside toward the center is provided on a bottom surface of the combustion furnace. The furnace wall near the surface is provided with a downward nozzle for jetting an air flow along the inclined surface. In the incinerator according to claim 6, in the incinerator according to any one of claims 1 to 5, the combustion furnace is formed by a lower combustion portion covered with a water-cooled jacket and the lower combustion portion. And an upper combustion portion covered with a heat insulating member so as to burn unburned components in the combustion gas.

According to the first aspect of the present invention, the swirling flow is formed above the gasification region by the swirling flow forming nozzle. The downward flow is formed by the swirl flow, but the downward flow is weakened by the downward flow suppression means being disposed between the gasification region and the region where the swirl flow forming nozzle is disposed, and the downward flow is reduced. Does not reach the gasification zone. According to the second aspect of the present invention, an air curtain forming nozzle having a flat shape in the vertical direction is provided as the downward flow suppressing means, and an air curtain extending in the vertical direction is formed. . Therefore, the formed air curtain acts to divide the swirling flow.
Therefore, a downward flow based on the swirl flow does not occur in the area where the air curtain is provided. According to the third aspect of the present invention, air curtain forming nozzles for creating an air curtain extending in the vertical direction are provided at equal intervals along the inner surface of the wall of the combustion furnace and at the center of the combustion furnace. The air curtains are formed at equal intervals by being arranged so that the swirling flow is effectively divided. Claim 4
In the described invention, in order to supply combustion air,
Since the combustion air supply nozzle is provided separately from the swirl flow forming nozzle, the amount of air from the swirl flow forming nozzle can be set relatively small. In this case, also in this case,
The swirl flow is effectively formed by the swirl flow forming nozzle ejecting air at a higher speed than the combustion air supply nozzle. According to the fifth aspect of the present invention, when an incineration object that tends to stay on the bottom surface is introduced, the incineration object is guided by the inclined surface and is urged to move from the outside toward the center. Therefore, the incinerated material does not remain as unburned material at the bottom corner. In addition, since the downward nozzle for ejecting the air flow is provided along the inclined surface, oxygen is supplied to the incineration material on the bottom surface to promote combustion. In the invention according to claim 6, since the lower combustion portion is covered with the water-cooled jacket, the temperature rise of the wall in the lower combustion portion is suppressed. Further, since the upper combustion part is covered with the heat insulating member, the combustion gas flowing through the upper combustion part is maintained at a high temperature. Therefore, in the upper combustion portion, the combustion of the unburned portion in the combustion gas is promoted.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

[First Embodiment] FIG. 1 shows a first embodiment of an incinerator according to the present invention.
Are a primary combustion furnace (combustion furnace) 30, a secondary combustion furnace 40, a cyclone dust collector 50, a jet scrubber 60, and a packed tower 7
0, etc.

As shown in FIG. 2, the primary combustion furnace 30 has a furnace wall 31, an inlet 32, a gas outlet 33, and an air supply port 3.
4. Combustion air supply nozzle 34a, swirl flow forming nozzle 35, air curtain forming nozzle (downflow suppressing means)
6. Inclined block 37, downward nozzle 38, ash outlet 3
9 and so on.

The furnace wall 31 has a cylindrical vertical shape and is formed by a water-cooled jacket. Input port 32
Is for charging incineration materials such as industrial waste such as waste plastic and general waste into the primary combustion furnace 30. The gas discharge port 33 is a discharge port of the combustion gas, and is connected to the secondary combustion furnace 40 at the subsequent stage.

The air supply port 34 is for supplying combustion air to the combustion air supply nozzle 34a. The combustion air supply nozzle 34a is provided over substantially the entire height of the primary combustion furnace 30 and, as shown in FIG. 3, toward the center of the primary combustion furnace 30 and
They are arranged at equal intervals in an annular shape and fixed to the furnace wall 31. Then, the air supplied from the air supply port 34 is jetted toward the inside of the primary combustion furnace 30. Combustion air supply nozzle 3
4a is arranged horizontally as shown in FIG.

The swirling flow forming nozzle 35 is provided in the primary combustion furnace 3.
0, and as shown in FIG.
The primary combustion furnace 30 is arranged eccentrically with respect to the center of the primary combustion furnace 30 and fixed to the furnace wall 31 so that a swirling flow 35 a can be formed. In this case, the orientation directions of all the swirling flow forming nozzles 35 are aligned in the same direction. The swirling flow forming nozzle 35 is fixed obliquely downward as shown in FIG. In this case, it is preferable that the swirl flow forming nozzle 35 faces downward as much as possible. This is because the gas can be mixed in a high temperature range and the residence time can be increased. Although not shown, the swirl flow forming nozzle 35
Is connected to a swirling flow forming air supply means. The air supply speed from the swirling flow forming nozzle 35 is set to be higher than the air supply speed from the combustion air supply nozzle 34a.

For example, an incinerated material containing plastic is once melted, gasified and burned. Usually, such gasification occurs at the bottom of the primary combustion furnace 30. The air curtain forming nozzle 36 is disposed between such a gasification region and the region where the swirl flow forming nozzle 35 is disposed. Then, as shown in FIG. 7, they are arranged at equal intervals (at 90 ° intervals in the illustrated example) toward the center of the primary combustion furnace 30 and along the inner surface of the wall, and are fixed to the furnace wall 31. I have. In this case, as shown in FIG. 8, the air curtain forming nozzle 36 is formed in a vertically flat shape so as to form an air curtain 36a extending in the vertical direction, and is fixed horizontally. Although not shown, an air curtain forming air supply unit is connected to the air curtain forming nozzle 36.

The inclined block 37 is, as shown in FIG.
An annular body having an annular inclined surface 37a descending from the outside toward the center, and has an outer shape of the primary combustion furnace 3
The shape is adapted to the corner of the bottom surface of the zero. The downward nozzle 38 is provided fixed to the furnace wall 31 in the vicinity of the inclined surface 37a of the inclined block 37, and is configured to blow air along the inclined surface 37a.
Although not shown, the downward nozzle 38 is connected to a downward nozzle air supply unit. The ash outlet 39
It is used to remove ash.

As shown in FIG. 1, the secondary combustion furnace 40 is provided at a stage subsequent to the primary combustion furnace 30, and is provided with a gas burner 41 to maintain the combustion gas from the primary combustion furnace 30 at a high temperature. It is for doing. C in combustion gas
When unburned components such as O and unburned hydrocarbons remain, the unburned components are oxidized in the secondary combustion furnace 40.

The cyclone dust collector 50 includes a secondary combustion furnace 40
This is provided at the subsequent stage for separating and recovering solids such as soot and dust contained in the combustion gas from the exhaust gas. The jet scrubber 60 is provided downstream of the cyclone dust collector 50, and serves to neutralize combustion gas and mainly remove hydrogen chloride.
The packed tower 70 is provided at the subsequent stage of the jet scrubber 60. The packed tower 70 has a longer residence time by being filled with metal particles, and cleans a combustion gas while showering with an NaOH aqueous solution.

The incinerator 20 is provided with NOx, S
Needless to say, a means for removing harmful gas such as Ox, a blower, a chimney, and the like may be provided.

In the incinerator 20 having the above configuration,
The object to be incinerated is thrown in from the slot 32 and incineration is performed. At this time, the incineration material is gasified in the lower part of the primary combustion furnace 30. The combustion gas generated by this gasification rises in the primary combustion furnace 30.

The combustion gas is supplied to the swirl flow forming nozzle 3.
When the combustion gas reaches the arrangement region 5, the mixing of the combustion gas with the combustion air is promoted by the turbulent vortex generated by the swirl flow 35a formed by the swirl flow forming nozzle 35.

In this case, the downward flow is generated by the formation of the swirl flow 35a, and there is a concern that gasification in the gasification region may occur more than necessary due to the downward flow. In the present embodiment, by providing the air curtain forming nozzle 36, such an adverse effect is eliminated. That is, by disposing the air curtain forming nozzle 36 between the gasification region and the arrangement region of the swirl flow forming nozzle 35, even if the downward flow based on the swirl flow 35a tries to reach the gasification region, Swirling flow 35a by vertical air curtain formed every 90 °
To prevent the downward flow based on the swirling flow 35a from affecting the gasification region.

Further, plastics and the like in the incineration material are once melted in the primary combustion furnace 30 and then gasified. Therefore, it tends to remain on the bottom of the primary combustion furnace 30 and remain unburned. In addition, if the furnace wall is a cooling wall (typically, a water-cooling wall), plastics, etc.
It is cooled by the furnace wall, so that even melting is hindered, and it is even easier to remain unburned. In the present embodiment, even when the incinerated material 80 that tends to remain on the bottom surface of the primary combustion furnace 30 and remain unburned is charged, the incinerated material 80 is not inclined. The movement toward the center from the outside is urged by being guided by the inclined surface 37a of 37. Moreover, in this case, since the incinerated material 80 does not directly contact the furnace wall 31 forming the water cooling jacket, the melting is not hindered, and the movement guided by the inclined surface 37a is further promoted. become. Therefore, the incinerated material 80 does not remain as unburned residue at the bottom corner. Moreover, since the downward nozzle 38 is provided so as to blow out the air flow along the inclined surface 37a, the incinerated material 80 on the bottom surface is supplied with oxygen enough to be gasified, and Because of the stirring action, the amount of unburned residue is reduced, and as a result,
0 combustion is promoted.

When the air nozzle is provided on the bottom surface, the air nozzle is closed by the molten plastic or the like. In this embodiment, however, the incinerated material 80 which tends to stay on the bottom surface of the molten plastic or the like is used. Such a phenomenon can be avoided by providing the downward nozzle 38 for supplying the air above the object 80 to be incinerated.

According to the incinerator 20, the swirl flow forming nozzle 35 can form the swirl flow 35a above the gasification region. By the swirling flow 35a, the mixing effect of the combustion gas and the combustion air can be increased, and the combustion efficiency can be improved. Moreover, in this case, since the air curtain forming nozzle 36 is disposed between the gasification region and the arrangement region of the swirl flow forming nozzle 35, the influence of the downflow based on the swirl flow 35a is reduced. Never reach. Therefore, it is possible to prevent an adverse effect of the downward flow, to cause appropriate gasification of the incineration material, and to eventually improve the combustion efficiency.

In this embodiment, a combustion air supply nozzle 34a is provided separately from the swirl flow forming nozzle 35 to supply combustion air. Can be set relatively small. In addition, since the swirl flow forming nozzle 35 blows out air at a higher speed than the combustion air supply nozzle 34a, the swirl flow 35a can be effectively formed.

Further, since the inclined surface 37a is provided on the bottom surface of the primary combustion furnace 30, the incinerated material does not remain as unburned material at the corner of the bottom surface. That is, no dead space is formed. Besides, this slope 3
Downward nozzle 38 for jetting airflow along 7a
Is provided, the incinerated material 80 on the bottom surface is provided.
Oxygen can be supplied to the incinerator, and the incinerated matter that tends to stay on the bottom surface of plastic or the like can be efficiently burned.

[Second Embodiment] FIG. 9 shows a primary combustion furnace (combustion furnace) 90 in a second embodiment of the incinerator according to the present invention. This embodiment is different from the first embodiment only in that the primary combustion furnace 90 includes a lower combustion section A and an upper combustion section B. The other configuration is the same as that of the first embodiment, and a description thereof will be omitted.

In the present embodiment, the lower combustion part A is
It is formed by a water cooling jacket 91. The upper combustion section B is formed by a brick (heat insulating member) 92.

In the present embodiment, the same functions and effects as those of the first embodiment can be obtained. In addition, since the lower combustion part A is formed by the water-cooled jacket 91, the temperature rise of the wall in the lower combustion part A can be suppressed. Further, since the upper combustion portion B is formed of the brick 92, the combustion gas flowing through the upper combustion portion B can be maintained at a high temperature. Therefore, in the upper combustion section B, combustion of unburned components in the combustion gas can be promoted. In this case, the upper combustion section B exhibits the same operation as the secondary combustion furnace, so that the secondary combustion furnace 40 can be made unnecessary depending on the incineration conditions.

It should be noted that the present invention is not limited to the above-described embodiment, but may be configured as follows. a) Instead of making the primary combustion furnace 30 a cylindrical vertical type,
Any form such as a square tube type or a horizontal type. In this case, it is needless to say that the dimensions, shape, orientation, and the like of the related members (the swirl flow forming nozzle 35, the air curtain forming nozzle 36, and the like) can be appropriately changed in accordance with the gist of the present invention. b) Instead of using the air curtain forming nozzle 36 as the descending flow suppressing means, another arbitrary means capable of suppressing the descending flow based on the swirling flow is used. For example, there is a nozzle that forms a swirling flow in the opposite direction to the extent that the swirling flow 35a can be weakened, or a flow speed of the swirling flow forming nozzle 35 at a lower position is set to be weak. c) Instead of using the vertical air curtain 36a, use a horizontal air curtain. d) Instead of disposing the swirling flow forming nozzle 35 downward, the nozzle 35 is disposed horizontally.

[0034]

According to the incinerator of the present invention, the following effects can be obtained. According to the incinerator according to the first aspect, the swirl flow forming nozzle can form a swirl flow above the gasification region to promote the mixing of the combustion gas and the combustion air. A downward flow is formed by the swirl flow, but the downward flow can be weakened by arranging the downward flow suppression means between the gasification region and the arrangement region of the swirl flow forming nozzle, The effect of the downflow does not reach the gasification zone. Accordingly, it is possible to prevent the gas from being adversely affected by the downward flow, to cause appropriate gasification, and eventually to improve the combustion efficiency. According to the incinerator according to the second aspect, the air curtain extending in the vertical direction is formed by providing the nozzle for forming the air curtain formed in a flat shape in the vertical direction as the downward flow suppressing means. be able to. Therefore, the air curtain acts to divide the swirling flow, so that a downward flow based on the swirling flow is not generated in a region where the air curtain is provided. According to the incinerator according to claim 3, the air curtain forming nozzles for creating the air curtain extending in the vertical direction are arranged at regular intervals along the inner surface of the wall of the combustion furnace and at the center of the combustion furnace. The air curtains can be formed at equal intervals by being arranged so that the swirling flow can be divided effectively.
According to the incinerator of the fourth aspect, since the combustion air supply nozzle is provided separately from the swirl flow forming nozzle to supply the combustion air, the air volume from the swirl flow formation nozzle is reduced. Can be set relatively small. Also in this case, since the swirling flow forming nozzle blows out air at a higher speed than the combustion air supply nozzle, the swirling flow can be effectively formed. According to the incinerator according to the fifth aspect, when an incineration object that tends to stay on the bottom surface is introduced, the incineration object is guided by the inclined surface and is urged to move from the outside toward the center. Therefore, the incinerated material does not remain as unburned material at the bottom corner. In addition, since the downward nozzle for ejecting the air flow along the inclined surface is provided, it is possible to supply oxygen to the incineration material on the bottom surface to promote combustion. According to the incinerator according to the sixth aspect, since the lower combustion portion is covered with the water-cooled jacket, it is possible to suppress an increase in the temperature of the wall in the lower combustion portion. Further, since the upper combustion section is covered with the heat insulating member, the combustion gas flowing through the upper combustion section can be maintained at a high temperature. Therefore, in the upper combustion portion, the combustion of the unburned portion in the combustion gas can be promoted.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of an incinerator of the present invention.

FIG. 2 is a longitudinal sectional view showing a primary combustion furnace in the incinerator shown in FIG.

FIG. 3 is a view showing an arrangement of a combustion air supply nozzle in the incinerator shown in FIG. 1, and is a sectional view taken along line III-III in FIG. 2;

FIG. 4 is an enlarged view showing a combustion air supply nozzle of FIG. 3;

5 is a view showing the arrangement of a swirl flow forming nozzle in the incinerator shown in FIG. 1, and is a sectional view taken along line VV in FIG. 2;

FIG. 6 is an enlarged view showing a swirl flow forming air supply nozzle of FIG. 5;

FIG. 7 is a view showing an arrangement of an air curtain forming nozzle in the incinerator shown in FIG. 1;
FIG. 2 is a sectional view taken along line II.

FIG. 8 is an enlarged view showing the nozzle for forming an air curtain of FIG. 7;

FIG. 9 is a longitudinal sectional view showing a primary combustion furnace in a second embodiment of the incinerator according to the present invention.

FIG. 10 is a sectional view showing an example of a conventional incinerator.

11 is an enlarged view showing a cross section taken along line XI-XI of the incinerator shown in FIG. 10;

[Explanation of symbols]

 Reference Signs List 20 incinerator 30 primary combustion furnace (combustion furnace) 34a combustion air supply nozzle 35 swirling flow forming nozzle 35a swirling flow 36 air curtain forming nozzle (downflow suppressing means) 36a air curtain 37a inclined surface 38 downward nozzle 80 incineration Object 90 Primary combustion furnace (combustion furnace) 91 Water-cooled jacket 92 Brick (heat insulation member) A Lower combustion part B Upper combustion part

Claims (6)

[Claims] 1. An incinerator provided with a combustion furnace for burning an incineration object while supplying combustion air, wherein the combustion furnace swirls combustion gas generated by gasification of the incineration object. A swirl flow forming nozzle disposed above the gasification region, and a gasification region and an arrangement region of the swirl flow formation nozzle acting to weaken a downward flow generated by the swirl flow. And a downflow suppressing means disposed between the incinerators. 2. The incinerator according to claim 1, wherein the downflow suppressing means is formed in a vertically flat shape so as to form an air curtain extending in a vertical direction. An incinerator characterized by being provided with. 3. The incinerator according to claim 2, wherein the air curtain forming nozzles are arranged at regular intervals along an inner surface of a wall of the combustion furnace and toward a center of the combustion furnace. An incinerator characterized in that: 4. The incinerator according to any one of claims 1 to 3, wherein the combustion furnace is provided with a combustion air supply nozzle for supplying the combustion air, The incinerator, wherein the forming nozzle blows out air at a higher speed than the combustion air supply nozzle. 5. The incinerator according to claim 1, wherein an inclined surface descending from the outside toward the center is provided on a bottom surface of the combustion furnace, and a furnace near the inclined surface is provided. An incinerator characterized in that the wall is provided with a downward nozzle for ejecting an air flow along the inclined surface. 6. The incinerator according to claim 1, wherein the combustion furnace includes a lower combustion portion covered with a water-cooled jacket, and the combustion gas generated in the lower combustion portion. And an upper combustion section covered with a heat insulating member so as to burn unburned components of the incinerator.