JP2003321572A - Processing equipment for chlorine-containing resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide processing equipment imparting high agitation performance to the objective resins to be processed and raising processing efficiency of the resin materials in the processing equipment for chlorine-containing resins in a rotary kiln system. <P>SOLUTION: The processing equipment for the chlorine-containing resin comprises an indirect heating-type rotary kiln provided with rake-up impeller blades raking up the objective resins by the rotation of the rotary kiln, installed inside of the rotary kiln which is the passing route of the objective resins in the longitudinal direction and circumferential direction in a proper intervals, and a part or whole of the rake-up impeller blades have holding parts for the objective resins. The tips of the impeller blades preferably have slopes against to the rotating direction of the inner wall of the rotary kiln at an angle of 5 to 90 degree. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a processing apparatus for dechlorinating chlorine-containing resins.

[0002]

2. Description of the Related Art In recent years, synthetic resins such as plastics have rapidly increased as industrial wastes and general wastes, and the treatment thereof has become a socially serious problem. Among them, chlorine-containing resins such as vinyl chloride have a problem that hydrogen chloride gas generated during combustion damages the furnace wall of the incinerator. For this reason, in reality, the large-scale disposal of chlorine-containing resins has to rely on the disposal of waste in landfills. However, the dumping of plastics causes land subsidence at landfills, is not desirable in terms of environmental protection, and recently, the shortage of land for landfill is becoming a social problem. Development of a mass processing method is earnestly desired.

Conventionally, a chlorine removal method using an indirect heating (external heating) type rotary kiln is known as a method for treating chlorine-containing resins. In this method, in order to heat the material to be treated uniformly and efficiently, and to prevent fusion and agglomeration of the resin materials, a solid heat medium (for example, sand, powder coke, powdered ore, together with the resin material to be treated is used. Granular material such as) is charged into the rotary kiln, the resin material to be treated is mixed with the solid heat medium by the rotation of the rotary kiln, and is heated while being transferred in the kiln, and the chlorine-containing resin is thermally decomposed by this heating. The chlorine content is desorbed as hydrogen chloride, and the thermal decomposition residue of the resin from which this chlorine content has been removed is recovered. On the other hand, exhaust gas containing hydrogen chloride is also recovered,
Hydrogen chloride is recovered and removed in the absorption tower.

In the treatment of such chlorine-containing resins, in order to improve the treatment efficiency and obtain a high dechlorination rate, the resin material to be treated is sufficiently agitated in the rotary kiln to form a lump of the resin material to be treated. It is necessary that the resin material to be treated and the solid heat medium be sufficiently mixed, while preventing the formation of resin and adhesion to the inner wall of the kiln. However, in the structure of the conventional rotary kiln, since the agitating property of the resin material to be treated is not sufficient, agglomeration of the resin material to be treated and adhesion of resin pyrolysis residue to the inner wall of the kiln are likely to occur. Since the particle size and the specific gravity are different from those of the treated resin material, segregation tends to occur with respect to the treated resin material in the rotary kiln.
Therefore, the conventional rotary kiln has a problem that sufficient processing efficiency cannot be improved.

With respect to such a problem, Japanese Patent Laid-Open No. 2000-
According to Japanese Patent No. 153523, in a chlorine-containing resin processing device including a rotary kiln of an indirect heating system, a scraping blade for scraping up a material to be processed by rotation of the rotary kiln is provided on an inner wall of the rotary kiln that is a passage of the material to be processed. An apparatus has been proposed in which a resin material to be treated can be highly agitated by providing the rotary kiln at appropriate intervals along the entire length in the longitudinal direction. 6 and 7
An example of such a conventional treatment apparatus for chlorine-containing resins is shown in FIG. On the inner wall of the rotary kiln body 1, scraping blades 2 for scraping up the workpiece 3 by rotation of the rotary kiln are provided at appropriate intervals along the entire length of the rotary kiln in the longitudinal direction. Further, the scraping blades 2 are provided at a plurality of locations in the circumferential direction of the inner wall of the rotary kiln body 1 (in FIG. 7, three locations at equal intervals in the circumferential direction).

[0006]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
If the apparatus described in Japanese Patent No. 523 is used, a high stirring property of the resin material to be treated can be obtained, so that agglomeration of the resin material to be treated and adhesion of the resin thermal decomposition residue to the inner wall of the kiln can be appropriately prevented, and the apparatus is relatively high. Processing efficiency can be obtained. However, there is a limit to improving the treatment efficiency by uniformly mixing the resin material to be treated, and there are cases where the above technique alone cannot deal with the improvement of the treatment efficiency.

Therefore, an object of the present invention is to solve the problems of the prior art and to obtain a high stirring property of the resin material to be treated in the apparatus for treating chlorine-containing resins by the rotary kiln system, and to treat the resin material to be treated. An object of the present invention is to provide a processing device capable of further improving the processing efficiency of.

[0008]

The features of the present invention for solving the above problems are as follows. (1) A rotary kiln of an indirect heating system. Raising blades for scraping the material to be processed by rotation of the rotary kiln on the inner wall of the rotary kiln, which is the passage of the material to be processed, are appropriately spaced in the longitudinal and circumferential directions of the rotary kiln. A treatment device for chlorine-containing resins, wherein part or all of the scraping blades have a treated material holding portion. (2) The front end of the scraping blade is inclined at an angle of 5 degrees or more and 90 degrees or less toward the direction in which the inner wall of the rotary kiln rotates, thereby forming a material holding part ( The treatment apparatus for chlorine-containing resins according to 1). (3) The tilt angle of the tip of the scraping blade toward the direction in which the inner wall of the rotary kiln rotates is different in the longitudinal direction of the rotary kiln, and the tilt angle is maximum in the central part of the rotary kiln. Equipment for processing chlorine-containing resins.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The treatment apparatus for chlorine-containing resins of the present invention comprises an indirect heating type rotary kiln. The indirect heating type rotary kiln is a thermal decomposition of a material to be treated by heat transfer from the outside of the rotary kiln body. It is a device that does. The rotary kiln used in the present invention has, on the inner wall of the rotary kiln serving as a passage for the material to be processed, scraping blades for scraping the material to be processed by the rotation of the rotary kiln at appropriate intervals in the longitudinal direction and the circumferential direction of the rotary kiln. A treatment device for chlorine-containing resins, characterized in that a part or all of the scraping blade has a material holding portion.

FIG. 1 and FIG. 2 show an embodiment of a treatment apparatus for chlorine-containing resins of the present invention. 1 is a sectional view, and FIG. 2 is a vertical sectional view. The treatment apparatus for chlorine-containing resins of the present invention is composed of the same members as the treatment apparatus for chlorine-containing resins which comprises an indirect heating type rotary kiln having scraping blades as shown in FIGS. 6 and 7. 1 is a resin material to be treated containing chlorine-containing resins or chlorine-containing resins (hereinafter,
This is the rotary kiln body into which the "material to be treated" is charged. On the inner wall of the rotary kiln body 1, scraping blades 2 for scraping up the material 3 to be processed by the rotation of the rotary kiln are provided at appropriate intervals in the longitudinal direction and the circumferential direction of the rotary kiln, that is, in the circumferential direction of the rotary kiln. The protrusions are provided at appropriate positions along the longitudinal direction of the rotary kiln at appropriate intervals.
A part or all of the scraping blade 2 is a workpiece holding portion 4
have.

The processing material holder holds the processing material 3 scraped from the lowermost part of the rotary kiln body 1 by the scraping blade 2 on the scraping blade 2 even if it rotates more than 90 degrees. Beyond 180 degrees Rotary kiln body 1
Has a function of dropping the material 3 to be processed from the scraping blade 2 until it reaches the lowermost part after the rotation (after the scraping blade has passed the uppermost part). As the processed material holding portion having such a function, any structure such as inclining the tip of the raking blade 2 toward the rotation direction of the rotary kiln body 1 or using the entire raking blade as an arc-shaped curved member can be used. Can be used.

As the material holding portion 4 of the scraping blade 2, the scraping blade tip end side is inclined at an angle of 5 degrees or more and 90 degrees or less toward the direction in which the inner wall of the rotary kiln rotates, and It is preferable to form the treatment material holding portion. The material holder 4 can be integrated with the scraping blade 2 or can be attached to the scraping blade 2 as a separate member for use. FIG. 1 shows a case where the tip of the scraping blade is inclined 90 degrees toward the direction in which the inner wall of the rotary kiln rotates. 3 and 4 are cross-sectional views of a rotary kiln showing another embodiment of the present invention. FIG. 3 shows a case in which the tip of the scraping blade is inclined 30 degrees toward the direction in which the inner wall of the rotary kiln rotates. The case where the tip of the scraping blade is inclined by 60 degrees toward the direction in which the inner wall of the rotary kiln rotates.

Further, as described above, the scraping blade tip end side is inclined at an angle of not less than 5 degrees and not more than 90 degrees toward the direction in which the inner wall of the rotary kiln rotates, thereby forming the workpiece holding portion. In the case of the tip of the scraping blade,
It is preferable that the angle of inclination of the inner wall of the rotary kiln is different in the longitudinal direction of the rotary kiln, and the angle of inclination is maximum in the central part of the rotary kiln. More preferably, the angle at which the tip of the scraping blade near the inlet of the rotary kiln is inclined toward the direction in which the inner wall of the rotary kiln rotates is inclined toward the side of the tip of the scraping blade near the outlet of the rotary kiln toward the side where the inner wall of the rotary kiln rotates. It is smaller than the angle.

In the processing apparatus of the present invention described above, the material to be processed is supplied into the rotary kiln body 1 from one end (inlet side) (usually, the solid heat medium is also supplied together with the material to be processed). By heating while transporting in the rotary kiln body 1, the chlorine-containing resin is thermally decomposed into a generated gas containing hydrogen chloride and a resin thermal decomposition residue, and the chlorine content in the chlorine-containing resin is removed. (Exit side)
Generated gas and resin pyrolysis residue are recovered from In such a dechlorination treatment of the material to be treated, the scraping blade 2 provided on the inner wall of the kiln stirs the material to be treated (and solid heat medium) by scraping the material to be treated by the rotation of the rotary kiln, Appropriately prevent agglomeration of treated resin material and adhesion of resin pyrolysis residue to the inner wall of the kiln. Material to be processed 3
Is processed by being thermally decomposed by heat transfer from the outside of the rotary kiln body 1, so that the scraped material 3 is held near the inner wall of the rotary kiln body 1 for a longer time, In FIG. 1, the tip end side of the scraping blade 2 is inclined at an angle of 90 degrees with respect to the rotation direction side of the rotary kiln main body 1, and the inclined portion holds the workpiece 3 during scraping, and The processing material holder 4 is formed.

The workpiece 3 scraped up by the scraping blade 2 at the bottom (lowermost part) of the rotary kiln body is shown in FIG.
In the case of the conventional linear raking blade perpendicular to the circumferential direction as shown in FIG. 1, if the rotary kiln body 1 rotates more than 90 degrees from the bottom, it falls from the raking blade 2, but the workpiece holder Due to the presence of No. 4, it is possible to scrape up to a higher position, the material to be treated 3 is heated by the wall surface of the rotary kiln body for a long time, the effective use range of the rotary kiln wall surface is expanded, and the amount of heat transfer used for processing is increased. Therefore, the processing efficiency can be improved. As a result, the processing amount of the material to be processed per unit time increases.

If the tip of the scraping blade is inclined toward the direction in which the inner wall of the rotary kiln rotates, the material to be processed is held during the scraping, which is effective, but if it is 5 degrees or less, the improvement of the processing efficiency is not remarkable. . On the other hand, if it exceeds 90 degrees, the material to be treated is hard to enter the inside of the blade, and is hard to drop from the scraping blade, and if it is kept held, it is melted and fixed, so that the tip side of the scraping blade is When forming the material holding portion by inclining, the angle of inclination of the inner wall of the rotary kiln to the direction of rotation is 5 degrees or more,
It is preferably 90 degrees or less.

Although the number of scraping blades 2 (the number of installed blades) provided in the circumferential direction of the inner wall of the rotary kiln is arbitrary, it is desirable to provide the scraping blades 2 at a plurality of positions, preferably at 3 or more positions in order to secure desired agitation property. Further, the total length of the scraping blades 2 in the longitudinal direction of the rotary kiln is preferably 40% or more of the total length inside the rotary kiln (effective heating length of the rotary kiln). If the total length of the scraping blades 2 is less than 40% of the total length inside the rotary kiln, it is difficult to obtain a sufficient stirring action.

The height of the scraping blade 2 in the centripetal direction of the rotary kiln is preferably not less than the maximum layer thickness of the material to be treated in the rotary kiln. The height of the scraping blade 2 is the height including the workpiece holding portion. Here, the maximum layer thickness of the material to be treated is the maximum layer thickness of the material to be treated including the solid heat medium when charged, and it is from the inner wall (bottom) of the kiln to the upper surface of the material layer to be treated. Refers to the maximum height. This maximum layer thickness can be calculated from the material filling rate in the kiln. If the height of the scraping blade is not more than the maximum layer thickness of the material to be processed, a part of the material to be processed may not be scraped up, and the agitation property of the material to be processed may be insufficient.

The scraping blades 2 adjacent to each other in the longitudinal direction of the rotary kiln can be provided at different positions in the circumferential direction of the inner wall of the kiln, that is, can be provided with staggered phases in the circumferential direction of the inner wall of the kiln, thereby further improving the stirring property. be able to. In addition, the inclination angle of the scraping blade tip side,
It can be changed in the longitudinal direction of the rotary kiln body, and the configuration shown below is effective.

In the case of treating a material containing water with a rotary kiln, in order to particularly improve the treatment efficiency in the central portion in the longitudinal direction of the rotary kiln body, the inclination angle of the scraping blade tip side is set to the inclination angle of the rotary kiln body. It is preferable to change it in the longitudinal direction and maximize it in the central part of the rotary kiln. For example, in FIG. 2, the inclination angle of the tip end side of the scraping blade near the entrance of the rotary kiln is 30 degrees toward the rotation direction side as shown in FIG. 3, and the vicinity of the central portion in the longitudinal direction is 90 degrees as shown in FIG. , 60 degrees around the exit as shown in FIG. 4, that is, I in FIG.
1 is a sectional view taken along line I-II, FIG. 3 is a sectional view taken along line III-III, and FIG. 4 is a sectional view taken along line IV-IV. With such a configuration, more efficient processing can be performed. The material to be treated in the vicinity of the inlet often contains water, and if heated too much, the chlorine-containing resin in the material to be treated will locally reach a high temperature before melting and water Part of chlorine-containing resin may adhere to the scraping blades by reacting with,
It has a bad effect on dechlorination. Therefore, it is preferable not to raise the treatment efficiency too much until the water vaporizes to some extent. Since the above-mentioned problem does not occur in the central portion in the longitudinal direction, the inclination angle is set to 90 degrees so as to maximize the processing efficiency. It is necessary to collect the generated gas and resin pyrolysis residue near the outlet, and if the material to be treated is scraped up to a position that is too high, the material that has become the powder resin pyrolysis residue will ride on the airflow inside the rotary kiln. However, it is not preferable because it is recovered as gas. Therefore, with the above configuration, the processing efficiency can be maximized effectively as a whole.

[0021]

EXAMPLES Examples using the processing apparatus of the present invention will be described below. The chlorine-containing resin was dechlorinated by using the treatment device of the present invention and the treatment device of the comparative example. The treated chlorine-containing resin is obtained by crushing agricultural vinyl to a particle size of 40 to 60 mm or less and reducing the volume to a lump with a diameter of 30 to 40 mm. Chlorine content rate: 30 mass%, ash content: 10 ma
ss%. Particle diameter of solid heat medium is 10 to 25 mm
Of powdered coke was used. The material to be treated is a mixture of a chlorine-containing resin and a solid heat medium. The solid heat medium is about 1/3 of the mass of the chlorine-containing resin (25 mass% of the material to be treated)
Mixed).

The specifications of the rotary kiln used in this embodiment are: kiln inner diameter: 1.8 m, kiln length (effective heating length): 13 m, and the temperature of the gas generated at the rotary kiln outlet is about 325 ° C. Adjust the heating gas temperature at the hot air generator outlet (heating gas temperature at the hot air generator outlet:
400-440 degreeC). Flow rate of carrier gas (nitrogen) in the kiln: 300 Nm ³ / h (N indicates standard state)
Used in.

The dechlorination rate of the chlorine-containing resin was calculated by the following formula.

[Dechlorination rate] = (1- [chlorine content of resin thermal decomposition residue] / [chlorine content of supplied chlorine-containing resin]) × 100 The inner wall of the rotary kiln has a height of 18 cm and a length of 1 m. Scraping blades are provided along the length of the kiln in the longitudinal direction at 13 locations, at equal intervals in the circumferential direction, at 16 locations perpendicular to the circumferential direction, and with respect to the scraping blades that are adjacent in the kiln longitudinal direction, in the kiln circumferential direction. The phase of the installation position of about 11.
It was shifted 5 degrees. A total of 208 scraping blades were installed. As the processing apparatus of the comparative example, the above-mentioned apparatus was used as it was, and as the processing apparatus of the present invention, a scraping blade to which a material holding portion was attached was used as shown below.

Of the 13 scraping blades in the longitudinal direction of the rotary kiln, two points on the inlet side are shown in FIG. 3, three points on the outlet side are shown in FIG. 4, and the remaining eight points in the central part are As shown in FIG. 1, a treatment material holding portion was attached to the tip of the scraping blade so as to have inclinations of 30, 60, and 90 degrees from the direction perpendicular to the circumference toward the rotation direction. As shown in FIGS. 1, 2, and 3, the member to be treated holding member was attached to all the scraping blades in the circumferential direction.

Kiln rotation speed: 1.0 rpm, the material to be treated is supplied from the raw material supply device into the rotary kiln while changing the treatment amount, and dechlorination treatment is performed by the treatment device of the present invention and the treatment device of the comparative example. It was Processing amount is 350-1200
The dechlorination rate was measured while changing to [kg / h]. The results are shown in FIG.

In the processing apparatus of the comparative example, the processing amount is 850.
The dechlorination rate was 96% or more up to [kg / h],
When the treatment amount per unit time was increased to 900 [kg / h], the dechlorination rate could not be maintained at 96% or more. On the other hand, when the treatment apparatus of the present invention was used, the dechlorination rate of 96% could be maintained even if the treatment amount was increased to 1200 [kg / h]. Therefore, it was found that the treatment amount can be increased by almost 50% and the treatment efficiency can be significantly improved.

[0028]

As described above, according to the present invention, a high agitation property of the resin material to be treated can be obtained, and at the same time, the treatment efficiency can be greatly improved, and a large amount of waste containing chlorine-containing resins can be treated. It becomes possible to do.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the device of the present invention.

FIG. 2 is a vertical sectional view showing an embodiment of the device of the present invention.

FIG. 3 is a cross-sectional view (inlet side) showing another embodiment of the device of the present invention.

FIG. 4 is a sectional view (outlet side) showing another embodiment of the device of the present invention.

FIG. 5 is a graph showing the relationship between the treatment amount and the dechlorination rate.

FIG. 6 is a vertical sectional view of a conventional device.

FIG. 7 is a sectional view of a conventional device.

[Explanation of symbols]

1, the rotary kiln body 2, scraping blade 3, material to be treated 4. Material holder

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Iemoto             1-2-1, Marunouchi, Chiyoda-ku, Tokyo             Main Steel Pipe Co., Ltd. (72) Inventor Tsukasa Ogawa             1-1 Minamiwata-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa             Nippon Steel Tube Co., Ltd. Keihin Steel Works Plastic             Kawasaki Branch Office F-term (reference) 4F301 AA17 CA09 CA24 CA26 CA41                       CA52 CA61 CA71

Claims (3)

[Claims] 1. An inner wall of the rotary kiln, which comprises an indirect heating type rotary kiln and serves as a passage for the material to be treated,
A treatment device for chlorine-containing resins, in which scraping blades for scraping a material to be processed by rotation of a rotary kiln are provided at appropriate intervals in a longitudinal direction and a circumferential direction of the rotary kiln, and a part of the scraping blades. Alternatively, the treatment device for chlorine-containing resins is characterized in that all of them have a treated material holding portion. 2. The treatment material holding portion is formed by inclining the scraping blade tip end side at an angle of 5 degrees or more and 90 degrees or less toward the side in which the inner wall of the rotary kiln rotates. The processing apparatus for chlorine-containing resins according to claim 1. 3. The tilt angle of the tip of the scraping blade with respect to the direction in which the inner wall of the rotary kiln rotates is different in the longitudinal direction of the rotary kiln, and the tilt angle is maximum at the center of the rotary kiln.
The processing apparatus for chlorine-containing resins according to 1.