JP3513798B2 - Fly ash dioxin pyrolysis equipment - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fly ash dioxin pyrolyzer in a refuse incinerator.

[0002]

2. Description of the Related Art A fly ash dioxin pyrolyzer for decomposing dioxin in fly ash by heat-treating fly ash in a refuse incinerator with a paddle stirrer in a reactor is conventionally known. In this device, since the length of the rotating shaft of the paddle stirrer is as long as about 5 m, in order to prevent the paddle and the reactor from coming into contact with each other due to thermal expansion or distortion of the shaft, the paddle and the inner wall surface of the reactor are separated from each other. A gap of about 10 mm is provided between them.

[0003]

In the above conventional fly ash dioxin pyrolyzer, fly ash that is in the gap between the paddle and the reactor inner wall surface and cannot be lifted by the paddle adheres to the reactor inner wall surface and solidifies. However, there was a problem that the efficiency of heat transfer to fly ash was reduced.

An object of the present invention is to remove fly ash adhering to the inner wall surface of the reactor to improve the heat transfer efficiency to fly ash in the reactor and shorten the heating time. To provide.

[0005]

A fly ash dioxin pyrolyzer according to the first invention is a fly ash for decomposing dioxin in fly ash by heating the fly ash in a reactor while stirring the fly ash with a paddle stirrer. In the dioxin pyrolyzer, the paddle of the paddle stirrer and the inner wall surface of the reactor
There is a gap between them , and a large number of impact-imparting solid particles are put in the reactor. The solid particles have a diameter of 20 to 100.
It is characterized in that a solid small piece having a spherical shape of mm and lifted together with the fly ash by a paddle gives a shock to the fly ash adhering to the inner wall surface of the reactor at the time of dropping, and peels it off.

The small solid pieces are lifted by the paddle together with the fly ash, and the fly ash adhering to the inner wall surface of the reactor is peeled off by the impact when falling apart from the paddle. This prevents the fly ash adhesion layer from being formed on the reactor inner wall surface, and improves the efficiency of heat transfer to fly ash in the reactor.

The spherical shape of the solid particles makes it easier for the solid particles to separate from the paddle, and also prevents damage to the reactor due to the impact of dropping the solid particles.

The solid pieces are preferably metal (eg stainless steel) or ceramic. The reactor is usually made of stainless steel, and by using the same material as the solid small piece, the drop impact of the solid small piece becomes sufficient and damage to the reactor due to this is prevented. Although the solid small pieces made of ceramic have a smaller drop impact than those made of stainless steel, they are thermochemically stable and it is possible to obtain a drop impact large enough to strip fly ash. It is superior to solid metal pieces in terms of preventing damage.

The diameter of the solid pieces is preferably 20 to 100 mm. The gap between the paddle and the inner wall of the reactor is 1
It is preferable that the diameter of the solid piece is about 0 mm. Therefore, if the diameter of the solid piece is 10 mm or less, the solid piece may not be lifted by the paddle. If the diameter of the solid piece is larger than 10 mm and smaller than 20 mm, Small pieces may get caught between the paddle and the inner wall of the reactor. Further, if the diameter of the solid small piece is larger than 100 mm, the impact at the time of dropping becomes too large and the reactor may be damaged.

400-500 before the solid pieces are loaded
It is preferably heated to ° C. By doing so, the solid small pieces themselves serve as a heating source for fly ash, so that the heating efficiency of fly ash is further improved.

The fly ash dioxin pyrolyzer according to the second invention is a fly ash dioxin pyrolyzer for decomposing dioxin in fly ash by heating the fly ash in a reactor while stirring the fly ash with a paddle stirrer. the radially outer end of the paddles in axial direction are arranged at equal intervals of the rotation axis, stripping section to strip the fly ash adhering to the reactor inner wall is provided, the stripping section, the disk mosquito
It is characterized by being formed by a cutter .

In the paddle stirrer, one is installed at the same position in the axial direction.
Paddle pairs consisting of two paddles arranged at an interval of 80 ° are provided at equal intervals along the axial direction, and adjacent paddle pairs are arranged at an interval of 90 °. .

The stripping portions are preferably arranged at equal intervals in the rotation axis direction of the paddle stirrer.

[0014] De Isukukatta end form, for example, a shape having a rounded, such circular. Also, the material is
Metals such as stainless steel are preferred. It is preferable that the disc cutters are arranged at intervals of 10 times or less than the gap formed between the paddle and the reactor inner wall surface.

It is preferable that the disc cutter provided on one side of the pair of paddles and the disc cutter provided on the other side are arranged so as to be staggered in the axial direction. As a result, a large number of disk cutters are arranged at equal intervals in the axial direction as a whole. The number of disc cutters provided on each paddle is, for example, one disc cutter provided on one of the pair of paddles near the end of the paddle and one disc cutter provided on the other one at the center of the paddle. To be taken.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the basic construction of a fly ash dioxin pyrolyzer according to the present invention. The fly ash dioxin pyrolyzer (1) includes a reactor (2) having an electric heater (3),
It is installed in the reactor (2) to stir fly ash and to react (2)
It is equipped with a paddle stirrer (4) for making the temperature distribution of the fly ash in the inside uniform. The paddle stirrer (4) has two paddles (6) arranged at the same position in the axial direction at 180 ° intervals.
Paddle pairs (6) and (6) are formed at equal intervals along the axial direction. Adjacent paddle pairs (6) (6) are arranged at 90 ° intervals from each other.

According to the fly ash dioxin pyrolyzer (1), the fly ash introduced into the reactor (2) from one end of the reactor (2) has a predetermined oxygen concentration (for example, 1 to 2) in an oxygen-deficient state. %), And is heated to a predetermined temperature (for example, 350 ° C.) while being stirred by the paddle stirrer (4), whereby dioxin is detoxified by the dechlorination reaction,
The decomposed gas is discharged from the other end of the reactor (2).

FIG. 2 schematically shows a cross section of a fly ash dioxin pyrolyzer according to the first invention. As described above, since the rotating shaft (5) of the paddle stirrer (4) has a long length of about 5 m, it is possible to prevent the paddle (6) and the reactor (2) from contacting each other due to thermal expansion or shaft distortion. Paddle to prevent
Between the radially outer end of (6) and the inner wall of the reactor (2),
There is a gap (G) of about 10 mm.
A fly ash adhesion layer with a thickness equivalent to (G) is likely to occur.

In the figure, the reactor (2) contains a large number of spherical solid pieces (7) for stripping off fly ash adhering to the inner wall surface of the reactor (2). Therefore, as the paddle stirrer (4) rotates, the solid small pieces (7) are
Is lifted together with the fly ash (see (b) in the figure),
When the inner end of the paddle (6) is inclined so as to face downward, the paddle (6) falls from the paddle (6) (see (c) in the figure). Due to the impact of dropping at this time, the fly ash attached to the inner wall surface of the reactor (2) is stripped off. The fly ash attached to the inner wall of the reactor (2) is lifted by the paddle (6) to remove solid small particles.
It is also stripped by friction with (7).

FIG. 3 shows the results of measuring the heat transfer efficiency of the case where the fly ash adhesion layer is 10 mm, 5 mm and none. In the figure, the vertical axis is the temperature in the reactor (2),
The horizontal axis represents heating time. According to the figure,
The time to heat the temperature inside the reactor (2) to 350 ° C is
If the fly ash adhesion layer is 10 mm (conventional device), 16
If the fly ash adhesion layer is 5 mm for more than 000 seconds, it will be about 11
000 seconds, without fly ash adhesion layer (of this invention)
Then, it is 6000 seconds or less, and it can be seen that according to the fly ash dioxin pyrolyzer of the present invention, the inside of the reactor (2) can be heated to a predetermined temperature in about one-third the time of the conventional case.

The solid small pieces (7) are preferably made of metal or ceramic and have a diameter of 20 to 100 mm. Further, the solid piece (7) is preferably heated to 400 to 500 ° C. before being charged into the reactor (2),
As a result, the solid pieces (7) serve as a heating source for fly ash, and the fly ash heating efficiency is improved.

FIGS. 4 and 5 show a first embodiment of a fly ash dioxin pyrolyzer according to the second invention. In the following description, the left and right in FIG. 4B will be referred to as the left and right. As shown in FIG. 4, in the fly ash dioxin pyrolyzer of the present invention, the paddles (6A) (6B) (6C) (6D) are attached to the inner wall surface of the reactor (2) at the radially outer ends thereof. A disc cutter (8) is attached as a stripping unit for stripping fly ash. Here, one paddle pair is coded as (6A) (6
B), which is adjacent to this on the left and right, and 9 in the circumferential direction.
The other paddle pair deviated by 0 ° is indicated by reference numerals (6C) and (6D). As shown in FIG. 4B, one paddle pair (6A) (6A)
In B), the paddle of (6A) has one disc cutter (8) near the left and right ends, and the paddle of (6B) has one disc cutter (8) in the center. ing. Similarly, in the other pair of paddles (6C) and (6D), one disc cutter (8) is provided on each of the (6D) paddles, and one disc cutter (8) is provided near the left and right ends. There is one cutter (8) in the center. Here, the distance between the two disc cutters (8) provided in (6A) and (6D) is set to 2W, and therefore, the distance between them is (6B).
The distances from the disk cutters (8) provided at (6C) and (6C) are W, respectively. Furthermore, the distance between the disc cutter (8) provided at the left end of the (6A) paddle and the disc cutter (8) provided at the right end of the (6D) paddle is
It is set to W. Thus, multiple disc cutters (8)
Are arranged at equal intervals in the axial direction of the rotating shaft (5).

Disc cutters adjacent to each other in the axial direction
The arrangement distance W of (8) is the gap (about 10 m) between the radially outer end of the paddles (6A) (6B) (6C) (6D) and the inner wall surface of the reactor (2).
m) 10 times or less than (G).

According to this fly ash dioxin pyrolyzer, as shown in FIG. 5, the disk cutter (8) enters the fly ash adhesion layer (9) and causes cracks therein, whereby the fly ash adhesion layer (9) is generated. (9) is destroyed and stripped.

FIG. 6 shows a second embodiment of the fly ash dioxin pyrolyzer according to the second invention. As shown in the figure, in this fly ash dioxin pyrolyzer, the paddle (10) is a leaf spring formed by stacking three inner plates of three metal plates having different lengths. There is. Then, the paddle (10) is deformed in an arcuate cross-section, so that the radially outer end of the paddle (10) is urged in the direction of coming into contact with the inner wall surface of the reactor (2). The radially inner end of the paddle (10) is fixed to the radially outer end of the paddle shaft (12) orthogonal to the rotating shaft (11) with bolts and nuts (13). The outer end of the paddle (10) is provided with a stripping portion (14) formed by bending the outer end of the longest metal plate at a substantially right angle. As shown in FIG. 6B, the stripping portion (14) is formed by a plurality of claws (14a) (14b) arranged at equal intervals in the axial direction of the rotating shaft (11). Here, the paddle (10) above the figure
In, the five claws (14a) are arranged at the same pitch as the claws (14a) at equal intervals, and the paddle (10) at the bottom of the figure has four claws (14a).
Four claws (14b) are located between the claws (14a) and claws (14a) of the paddle (10) at the top of the figure, which results in a plurality of claws (14a) (14b). Are arranged so as to be staggered along the axial direction.

According to this fly ash dioxin pyrolyzer, even if the outer end of the paddle (10) approaches the inner wall surface of the reactor (2) due to thermal expansion and axial distortion, it is regarded as a leaf spring. Since the paddle (10) is deformed and absorbs it, the stripping section (14) always comes into contact with the inner wall surface of the reactor (2) to strip the fly ash adhesion layer.

In the above description, the adjacent paddle pairs are arranged so as to be spaced apart from each other by 90 °, but the adjacent paddle pairs do not have to be displaced from each other, and a predetermined value other than 90 ° is provided. It may be arranged at intervals.

According to the fly ash dioxin pyrolyzer of the second invention, the fly ash adhesion layer is destroyed and stripped off, so that the fly ash adhesion layer becomes 0 mm, and as shown in FIG.
The heat transfer efficiency is significantly improved as compared with the adhesive layer having a thickness of 10 mm.

[0030]

According to the fly ash dioxin pyrolyzer of the present invention, the formation of an adhering layer of fly ash on the inner wall of the reactor is prevented and the fly ash agitation property is improved. The heat transfer efficiency is improved, the fly ash temperature is made uniform, and the dioxin dechlorination reaction is promoted. Therefore, the heating time can be greatly shortened, and the apparatus can be made compact and the processing capacity can be improved.

[Brief description of drawings]

FIG. 1 is a perspective view showing the outline of a fly ash dioxin pyrolyzer.

FIG. 2 is a diagram schematically showing the fly ash dioxin pyrolyzer of the first invention.

FIG. 3 is a graph showing the effect of the fly ash dioxin pyrolyzer of the present invention.

FIG. 4 is a diagram schematically showing a fly ash dioxin pyrolyzer of the second invention, in which (a) is a transverse sectional view and (b) is a plan view.

FIG. 5 is a diagram schematically showing the operation of the fly ash dioxin pyrolyzer of the second invention.

6A and 6B are diagrams schematically showing a fly ash dioxin pyrolyzer of the third invention, wherein FIG. 6A is a horizontal sectional view, and FIG. 6B is a vertical sectional view taken along the line bb of the same figure. .

[Explanation of symbols]

(1) fly ash dioxin pyrolysis apparatus (2) reactor (4) paddle stirrer (6) paddle (7) Solid pieces (8) disk cutter (stripping section) (10) paddle

Continuation of front page (51) Int.Cl. ⁷ Identification code FI A62D 3/00 651 B09B 3/00 303L 654 ZAB (72) Inventor Yasuo Sato 1-789 Minami Kohoku, Suminoe-ku, Osaka-shi Hitachi Zosen Corporation (72) Inventor Minoru Hasegawa 1-789 Minamikohoku, Suminoe-ku, Osaka City Hitachi Shipbuilding Co., Ltd. (72) Inventor Tsuyoshi Kato 1-789 Minamikohoku, Suminoe-ku, Osaka City Hitachi Shipbuilding Co., Ltd. ( 56) References JP-A-7-171367 (JP, A) JP-A-10-15372 (JP, A) JP-B-57-43051 (JP, B2) Utility model registration 2518887 (JP, Y2) (58) Survey Areas (Int.Cl. ⁷ , DB name) B09B 3/00 A62D 3/00 F23J 1/00 B01F 7/00-7/32

Claims (7)

(57) [Claims] 1. A fly ash dioxin pyrolysis apparatus for decomposing dioxins in the fly ash by the heat treatment in the reactor (2) with stirring by a paddle stirrer (4) fly ash, paddle stirrer (4 ) Paddle (6) and reactor (2)
There is a gap between the inner wall surface and a large number of impact-imparting solid particles (7) inside the reactor (2 ).
Has a spherical shape with a diameter of 20 to 100 mm, and the small solid pieces (7) lifted together with the fly ash by the paddle (6) impact the fly ash attached to the inner wall surface of the reactor (2) when it falls. A fly ash dioxin pyrolysis device characterized by being stripped off. 2. A solid piece (7) is fly ash dioxin pyrolysis apparatus according to claim 1 wherein the metal. 3. The solid particles (7) are ceramics.
1. The fly ash dioxin pyrolyzer of 1 . 4. From 400 to before the solid small pieces (7) are charged.
Any of claims 1 to 3 which is heated to 500 ° C.
The fly ash dioxin pyrolyzer of Crab . 5. A fly ash dioxin pyrolyzer for decomposing dioxin in fly ash by heat treating fly ash in a reactor (2) while stirring the fly ash with a paddle stirrer (4), a rotary shaft (5 ) At the radially outer end of the paddles (6A) (6B) (6C) (6D ) that are arranged at equal intervals in the axial direction, the stripping part that strips off the fly ash adhering to the inner wall surface of the reactor (2) (8 )
Is provided and the stripping part (8) is
The fly ash dioxin pyrolysis device is characterized by being formed by . 6. The disc cutter (8 ) is a paddle stirrer (4).
Claims, which are arranged at equal intervals in the axial direction of the rotating shaft (5 )
5. The fly ash dioxin pyrolysis device described in 5 . 7. The disc cutter (8) has an arrangement interval (W) along the axial direction such that the paddles (6A) (6B) (6C) (6D) and the reactor (2) are arranged.
The fly ash dioxin pyrolysis device according to claim 5 or 6, wherein the gap (G) formed with the inner wall surface is 10 times or less.