JP2005265323A - Rotary kiln device and pyrolyzing facility - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform stirring and transport of crude material and its pyrolysis by forming vanes for stirring and transport in the optimum conditions according to the properties of the crude material to be stirred and transported. <P>SOLUTION: At 90-degs. intervals in axial direction, parts 27 furnished at the inside surfaces with dovetail grooves 27a are formed on the inner walls of rotary kilns 1 and 2 formed in a cylindrical shape rotatably, and a vane 28 for stirring and transport is inserted removably in each dovetail groove 27a. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a facility for reducing and reducing the amount of raw materials containing various organic substances (solids containing various organic substances, various sludges, soils, etc.) by a thermal decomposition reaction, and in particular, a stirring / conveying blade in a rotary kiln The present invention relates to a rotary kiln apparatus and a thermal decomposition facility that facilitate the change of the above.

  Various raw materials (treated materials), various organic substances, various sludges, soil, earth and sand, etc. are pyrolyzed in a reducing atmosphere by indirect heating, and processing such as drying, carbonization, ashing, purification is added. Has been done. When using a pyrolysis means that contains raw materials inside the rotary kiln and thermally decomposes the raw materials by indirect heating, the rotary kiln is designed to effectively stir and transport the raw materials including heating efficiency. Ingenuity is given. For example, installation of a plurality of blades, a device for the furnace inner wall, and the like.

  In Patent Documents 1 and 4, the heat transfer tube (blade) in the rotary kiln is provided to be inclined forward, and in Patent Documents 2 and 3, the rotary kiln is inclined downward from the upstream side toward the downstream side. The blades are fixed to the inner wall of the rotary kiln. Also in Patent Document 4, the blades are fixed to the inner wall of the rotary kiln. In Patent Document 5, the rotary kiln is provided with an inclination. At the same time, the inner wall of the rotary kiln is formed in a polygonal shape, so that stirring and transport can be effectively performed.

Moreover, in patent document 6, the blade which devised the shape was fixed to the inner wall of a rotation kiln, and in patent document 7, the blade | wing which devised the shape and arrangement | positioning was provided in the inner wall of the rotation kiln. Shows that the pin-shaped projections are provided at predetermined intervals on the inner wall of the rotary kiln. In Patent Document 9, the inner wall of the rotary kiln is provided with blades devised in shape and arrangement. In Patent Document 10, A plurality of spiral lifters are provided on the inner wall of the rotary kiln.
JP 2002-156105 A JP 2000-97567 A JP 2000-153523 A JP 2000-249475 A JP-A-7-120161 JP-A-8-110164 Japanese Patent Laid-Open No. 11-63830 Japanese Patent Laid-Open No. 10-267239 Japanese Patent Laid-Open No. 10-54523 JP-A-8-233234

  As described above, in the conventional rotary kiln apparatus and the thermal decomposition facility, the rotary kiln is provided with blades for stirring and conveying the raw material, and the blades have properties of the raw material, residence time, rotational speed of the rotary kiln, etc. The height, length, inclination angle, etc. are determined in consideration of the above. However, although the blade shape and arrangement conditions according to the properties of various raw materials are technically accumulated, it is unclear unless they are actually operated, and conventionally, all the blades in the rotary kiln are fixed. Therefore, it is not easy to change the blade installation position and the like, and it has been dealt with by limited means such as adjustment of the rotational speed of the rotary kiln (adjustment of residence time) and adjustment of the heating temperature.

  In addition, there are many cases where it is difficult to obtain the amount of raw material suitable for the actual load test, and the sample test result with a small amount of raw material is good. In reality, there is a discrepancy with the results of sample tests. This is due to an increase in the operating cost of the facility due to the fact that the optimum pyrolysis treatment cannot be performed on the raw material, the consumption of the heating source fuel increases, and the operation time is prolonged.

  The inventor makes it easier to eliminate the discrepancy between the result of the previous sample test and the actual load test, and is more flexible than the limited conditions such as adjusting the rotation speed and heating temperature of the rotary kiln. With the aim of carrying out effective thermal decomposition treatment of raw materials according to the response, we have intensively studied. As a result, since the stirring / conveying blades in the conventional rotary kiln are fixed, the adjustment range is limited, so that the blades provided on the inner wall of the rotary kiln can be attached and detached so that the blades can be easily changed. Focused on. As a result, it is possible to easily cope with the properties of various raw materials, and there are subtle differences in the properties of raw materials with the same name depending on the location of the occurrence, etc., making it easy to handle such cases. I found.

  The present invention has been made to solve the above-described problems, and can be used as an agitating / conveying blade under optimum conditions according to the properties of the raw material to be agitated / conveyed. It is an object of the present invention to obtain a rotary kiln device and a thermal decomposition facility that can efficiently perform the thermal decomposition that is optimal for the raw material.

  A rotary kiln apparatus according to claim 1 of the present invention is a rotary kiln apparatus that includes a plurality of stirring / conveying blades in a circumferential direction and an axial direction in a cylindrical rotating kiln that is rotatable. It is what.

  The thermal decomposition facility according to claim 2 is provided with a plurality of stirring / conveying blades in a circumferential direction and an axial direction in a rotatable and cylindrical rotary kiln, and raw material introducing means and discharging means at both ends of the rotary kiln. The agitating / conveying blade is detachable in a thermal decomposition facility provided with a thermal decomposition means for storing a raw material in a rotary kiln and thermally decomposing the raw material by indirect heating.

  According to a third aspect of the present invention, the agitation / conveying blade is inserted into a dovetail groove formed on the inner wall of the rotary kiln.

  According to a fourth aspect of the present invention, the agitation / conveying blade is divided into a plurality of parts and provided over substantially the entire length of the rotary kiln.

  In the thermal decomposition facility according to claim 5, the agitation / conveying blade is integrally formed and provided over substantially the entire length of the rotary kiln.

  In the pyrolysis facility according to claim 6, the agitating / conveying blade is provided with an inclination angle of zero degrees or more with respect to the axial direction of the rotary kiln.

  In the thermal decomposition facility according to claim 7, the agitation / conveying blade is eccentric or eccentric with respect to the axial direction of the rotary kiln.

  As described above, according to the present invention, the stirring / conveying blade is detachably provided on the inner wall of the rotary kiln, and is replaced with the stirring / conveying blade having the optimum shape and arrangement in accordance with the properties of the raw material to be stirred / conveyed. This makes it possible to efficiently stir and convey the raw material including the heating efficiency, thereby effectively performing the optimum thermal decomposition on the raw material. Therefore, it is possible to reduce the operating cost of the facility, such as reducing the heat source fuel and the operating time.

  The best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 2 is a block diagram of a thermal decomposition facility according to the best mode of the present invention. Reference numerals 1 and 2 denote cylindrical rotary kilns. The rotary kilns 1 and 2 are heated from the outside around the rotary kilns 1 and 2, respectively. External heating means 3 and 4 are provided, a rotary kiln 1 and external heating means 3 form a drying furnace (heating hot air temperature 300 to 450 ° C.), and a rotary kiln 2 and external heating means 4 form a carbonization furnace (heating Hot air temperature 400-650 ° C.) is formed. Hot air gas is introduced into the external heating means 4 from a hot air furnace 5 having a combustion burner, and this hot air gas is also introduced into the external heating means 3 and then exhausted through a pipe 19.

  At one end of the rotary kiln 1, a hopper 6 for holding the raw material, a motor-driven transfer means 7 and a charging box 8 are provided, and the other end of the rotary kiln 1 is connected across the other end of the rotary kiln 2. A box 9 is provided. In addition, annular protrusions 1 a and 1 b are provided on the outer periphery of the portion near both ends of the rotary kiln 1, and the protrusions 1 a and 1 b are rotatably supported by the rotation support rollers 10 and 11. A sprocket is provided on the projecting portion 1 b side of the rotary kiln 1, and the sprocket and a motor 12 that is a driving source are connected by a chain 13.

  Similarly, protrusions 2a and 2b are provided at both end portions of the rotary kiln 2, and the protrusions 2a and 2b are rotatably supported by the rotation support rollers 14 and 15, respectively. Are connected by a chain 17 via a sprocket. A collection box 18 is provided on one end side of the rotary kiln 2.

  A pipe 20 is branched and connected to the pipe 19, and a circulation blower 21 and an ejector blower 22 are provided in the pipe 20. The pipe 20 is connected to a gas combustion furnace 23 having an ejector and a combustion burner. Further, the connection box 9 is connected to the gas combustion furnace 23 through a pipe 24, and a cracked gas made of dry distillation gas, water vapor, etc. generated by the raw material drying process is fed into the gas combustion furnace 23 for combustion purification. The combustion exhaust gas from the gas combustion furnace 23 is discharged through the gas-gas heat exchanger 25 and the like. The heat exchanger 25 and the hot stove 5 are connected by a pipe 26.

  1 (a) to 1 (d) show a side view of a rotary kiln apparatus, a front view, a side view and a plan view of a stirring / conveying blade, respectively, and the length of the inner walls of the rotary kilns 1 and 2 at intervals of 90 degrees. Four dovetail groove forming portions 27 are attached by welding along the direction, and dovetail grooves 27 a are formed on the inner surface side of the dovetail groove forming portion 27. A support portion 28a of the stirring / conveying blade 28 is detachably inserted into the dovetail groove 27a, and the blade portions 28b are welded at regular intervals in the length direction on the inner surface of the support portion 28a. Various types of blades 28b having different lengths L, heights H, and angles θ with respect to the axial directions of the rotary kilns 1 and 2 are prepared, and the blades 28b having the optimum conditions according to the properties of the material to be conveyed are selected. To do. The support portion 28a is provided over substantially the entire length of the rotary kilns 1 and 2, but is divided into a plurality at the divided portion 28c. Reference numeral 29 denotes a divided unit block of the agitating / conveying blade 28 including a support portion 28a and a blade portion 28b welded to the support portion 28a. Thus, a plurality of stirring / conveying blades 28 are detachably provided in the circumferential direction and the axial direction of the rotary kilns 1 and 2.

  Next, the operation of the above configuration will be described. The raw material (object to be processed) is charged into the rotary kiln 1 through the hopper 6, the conveying means 7 and the charging box 8. The rotary kilns 1 and 2 are rotationally driven by the motors 12 and 16, and the workpieces introduced into the rotary kiln 1 are conveyed to the discharge side while being agitated by the agitating / conveying blades 28. The inside of the rotary kiln 1 is heated to a predetermined temperature by hot air gas, and the object to be processed is dried (moisture removed) by indirect heating to become a dried substance, which is discharged to the connection box 9. In the connection box 9, the dried material is guided by the guide 9 a and fed into the other end of the rotary kiln 2. Also in the rotary kiln 2, the dried product is conveyed while being agitated by the agitating / conveying blades 28. In the meantime, the dried product is also indirectly heated by the hot air gas from the hot air furnace 5, and the dried product is thermally decomposed (carbonized). As a result, the carbide is recovered, and the carbide is recovered from one end of the rotary kiln 2 through the recovery box 18.

  Pyrolysis gas generated in the rotary kilns 1 and 2 is introduced into the gas combustion furnace 23 from the connection box 9 through the pipe 24 and is purified by combustion. The gas combustion furnace 23 is heated by its own combustion burner, and part of the hot air gas discharged from the external heating means 3 is fed through the pipe 20 and heated to about 850 ° C. The combustion exhaust gas from the gas combustion furnace 23 is introduced with temperature-adjusted air, and then heat-exchanged with external air in the heat exchanger 25 and cooled to 200 to 150 ° C. External air heated by heat exchange is introduced into the hot stove 5. On the other hand, the cooled combustion exhaust gas is discharged from the chimney through the bag filter and the exhaust blower.

  In the above-described best embodiment, the stirring / conveying blades 28 are detachably provided on the inner walls of the rotary kilns 1 and 2, and the stirring / conveying blades 28 are formed according to the results of a prior sample test. If it is found that the fit is insufficient, it is necessary to change a part or the front part of the stirring / conveying blade 28. However, since the stirring / conveying blade 28 is detachable, its change is easy. Further, various agitating / conveying blades 28 having different heights, lengths, and inclination angles of the blade portions 28b of the agitating / conveying blades 28 are formed in advance, and among them, the agitating / conveying blade 28 most suitable for the actual load is formed. By selecting this, it is possible to obtain the stirring / conveying blade 28 under the optimum conditions according to the properties of the raw material to be agitated / conveyed, and to stir / convey the raw material efficiently including heating efficiency. As a result, the optimum thermal decomposition of the raw material can be performed effectively. Therefore, it is possible to reduce the operating cost of the facility, such as reducing the heat source fuel and the operating time.

  3 (a) and 3 (b) show a case where the support portion 28a of the stirring / conveying blade 28 is divided and integrated, and in any case, the support portion 28a extends over the substantially entire length of the rotary kilns 1,2. Is provided. Further, as shown in FIG. 1 (d), the blade portion 28b is provided with an inclination angle θ. However, the inclination angle θ may be zero degrees or more. Furthermore, although the blade | wing part 28b was provided in the eccentric state in the axial center direction of the rotary kilns 1, 2, you may provide in an eccentric state. Moreover, although the shape of the stirring / conveying blade 28 is a flat plate shape, it may be a curved plate shape or a bent plate shape.

It is the side view of the rotary kiln apparatus by this Embodiment, and the front view, side view, and top view of a stirring / conveyance blade | wing. It is a block diagram of the thermal decomposition facility by embodiment best. It is a front view of the stirring and conveyance blade | wing in the case of the division | segmentation structure and integral structure by the best embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 2 ... Rotary kiln 3, 4 ... External heating means 8 ... Input box 9 ... Connection box 10, 11, 14, 15 ... Rotation support roller 18 ... Collection box 27 ... Dovetail groove formation part 27a ... Dovetail groove 28 ... Stirring / Conveying blade 28a ... support portion 28b ... blade portion 28c ... dividing portion

Claims (7)

  A rotary kiln apparatus comprising a plurality of agitating / conveying blades in a circumferential direction and an axial direction in a rotatable and cylindrical rotating kiln, wherein the agitating / conveying blades are detachable.   A plurality of agitating and conveying blades are provided in the circumferential direction and the axial direction in a rotatable, cylindrical rotary kiln, and raw material introduction means and discharge means are provided at both ends of the rotary kiln, and raw materials are stored inside the rotary kiln. A thermal decomposition facility comprising a thermal decomposition means for thermally decomposing the raw material by indirect heating, wherein the stirring / conveying blade is detachable.   The thermal decomposition facility according to claim 2, wherein the agitating / conveying blades are inserted into dovetail grooves formed on the inner wall of the rotary kiln.   The thermal decomposition facility according to claim 2 or 3, wherein the stirring / conveying blade is divided into a plurality of parts and provided over substantially the entire length of the rotary kiln.   The thermal decomposition facility according to claim 2 or 3, wherein the agitation / conveying blade is integrally formed and provided over substantially the entire length of the rotary kiln.   The thermal decomposition facility according to any one of claims 2 to 5, wherein the stirring / conveying blade has an inclination angle of zero degrees or more with respect to an axial direction of the rotary kiln.   The pyrolysis facility according to any one of claims 2 to 6, wherein the agitating / conveying blade is oriented or eccentric with respect to the axial center direction of the rotary kiln.

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