JP2010127607A - Rotary kiln - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary kiln that can effectively cool the ends of a kiln body protectively. <P>SOLUTION: An outlet hood 10 disposed at a back end of the kiln body 3 has an annular sealing material fixing piece 14 protruded along an outer peripheral surface of the kiln body 3. A base end of a seal plate 15 for outside air infiltration prevention is fixed to the tip of the sealing material fixing piece 14, and a free end of the seal plate 15 is abutted against the outer peripheral surface of the kiln body 3. An outside air intake means is disposed to admit outside cooling air A to a clearance space 16 formed by the outer peripheral surface of the kiln body 3, the sealing material fixing section 14 and the seal plate 15. When an object R is incinerated or burned, the outside air intake means admits an appropriate amount of the outside cooling air A to effectively cool the end of the kiln body 3 protectively. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a rotary kiln used for incineration treatment of combustible waste, firing processing of inorganic materials, etc., and in particular, the inner circumference of the kiln main body so as to be able to cope with the case where the incineration processing or firing processing is performed at a high temperature. It relates to a rotary kiln with heat-resistant casters on the surface.

  Conventionally, for example, a rotary kiln has been adopted when incineration of combustible waste such as waste wood and waste plastic, or baking of various inorganic materials. In this type of rotary kiln, a kiln main body, in which a heat-resistant caster such as a refractory brick or ceramics is provided around the inner peripheral surface of a cylindrical steel plate, is rotatably supported, and hoods are provided at both ends of the kiln main body. The inlet hood on the processed product supply side is provided with a burner for supplying hot air and processed product supply means such as a conveyor and a pusher, while the outlet hood on the processed product discharge side is incinerated or baked. It is equipped with a discharge hopper that discharges the processed material and a flue for exhaust gas discharge. The above configuration shows the case of a parallel flow type rotary kiln in which the flow direction of the treatment object and the hot air is the same in the kiln body, and the counter flow type rotary kiln in which the flow direction of the treatment object and the hot air is reversed. In some cases, the inlet hood is provided with a workpiece supply means and an exhaust flue, while the outlet hood is provided with a burner and a discharge hopper.

  The inlet hood and the outlet hood are each provided with an annular sealing material fixing piece slightly larger in diameter than the kiln main body along the outer peripheral surface of the kiln main body, and the distal end portion of each sealing material fixing piece. For example, the base end portion of a metal seal plate or the like is fixed, and the free end portion of the seal plate is brought into contact with the outer peripheral surface of the kiln main body to be in contact with the kiln main body. The gap between the kiln main body, the inlet hood and the outlet hood is sealed so as to suppress the intrusion of outside air as much as possible.

  By the way, in such a rotary kiln, as described in Patent Document 1 (Japanese Patent Application Laid-Open No. 2006-29667), since there is a large difference in the thermal expansion coefficient between the steel plate and the caster that are in close contact with each other, In the case of incineration or firing treatment, there is a possibility that the caster may crack or peel off from the steel plate. In particular, in order to prevent the synthesis of dioxins during incineration of waste, the incineration temperature must be raised to about 800 ° C or higher, and the heat storage property of the caster itself is very high, and it is high for a long time. Therefore, the steel sheet exposed to the high temperature radiant heat for a long time may be easily deformed.

And with respect to such a problem, in the said patent document 1, while covering the outer peripheral surface of the steel plate of a kiln main body with a jacket cover, cooling air is forced to flow in into this jacket cover with a fan. The steel plate is cooled from the outer peripheral surface to suppress thermal expansion and prevent the caster and the steel plate from being damaged or deformed.
JP 2006-29667 A

  However, in the conventional rotary kiln, although the central portion of the kiln main body is cooled, the end portion thereof is not subjected to the cooling process. As described above, the kiln main body end portion is configured so as to overlap with the sealing material fixing piece of the hood, so that it is relatively easy to accumulate heat, and from the caster provided around the inner peripheral surface of the sealing material fixing piece. Because high temperature radiant heat is emitted over a long period of time, the above-mentioned problems such as deformation and damage are expected to appear more prominently on the outer peripheral surface of the kiln main body adjacent to the kiln main body. It is considered that some cooling process needs to be performed on the part.

  This invention makes it a subject to provide the rotary kiln which can cool and protect the end part of a kiln main body effectively in view of said point.

  In order to solve the above-mentioned problems, in the rotary kiln according to claim 1 according to the present invention, a rotary kiln comprising a kiln body in which a heat-resistant caster is provided on an inner peripheral surface of a cylindrical steel plate is rotatably supported. In the above, a hood provided at the end of the kiln main body is provided with an annular sealing material fixing piece projecting along the outer peripheral surface of the kiln main body, and a seal material for preventing entry of outside air is provided at the tip of the sealing material fixing piece. While fixing the base end portion, the free end portion of the seal material is brought into contact with the outer peripheral surface of the kiln main body, and a cooling space is formed in a gap space formed by the outer peripheral surface of the kiln main body, the seal material fixing piece, and the seal material. An outside air introduction means for introducing outside air is provided.

  According to a second aspect of the present invention, the rotary kiln includes an air socket that communicates the gap space and the outside air as the outside air introduction means, and the air socket is detachably equipped with an air plug that blocks the communication. Yes.

  The rotary kiln according to claim 3 is characterized in that the gap between the outer peripheral surface of the kiln main body and the sealing material fixing piece of the hood has a labyrinth structure capable of attenuating the flow rate of the outside air introduced by the outside air introduction means. .

  According to the rotary kiln according to claim 1 of the present invention, an annular sealing material fixing piece is projected along the outer peripheral surface of the kiln main body on the hood provided at the end of the kiln main body, and the tip of the sealing material fixing piece While fixing the base end portion of the sealing material for preventing entry of outside air to the part, the free end portion of the sealing material is brought into contact with the outer peripheral surface of the kiln main body, and the outer peripheral surface of the kiln main body, the sealing material fixing piece, and the sealing material Since the outside air introduction means for introducing outside air for cooling into the gap space formed by the above is provided, the end of the kiln main body that overlaps the sealing material fixing piece of the hood can be effectively cooled and protected, and the deformation of the steel plate The caster can be prevented from being damaged or peeled off.

  Further, according to the rotary kiln according to claim 2, as the outside air introduction means, it is provided with an air socket for communicating the gap space and the outside air, and the air socket is detachably equipped with an air plug for blocking communication. The introduction / non-introduction of outside air can be easily switched by the operation of attaching / detaching the air plug, and a flexible response such as appropriately performing a cooling process as required becomes possible. If a plurality of air sockets and air plugs are provided, the amount of outside air introduced can be easily adjusted by adjusting the number of attached and detached air plugs, and a suitable cooling process corresponding to the processing temperature can be realized.

  According to the rotary kiln of claim 3, since the gap between the outer peripheral surface of the kiln main body and the sealing material fixing piece of the hood has a labyrinth structure capable of attenuating the flow rate of the outside air introduced by the outside air introducing means, When the introduction operation is performed, the amount of outside air introduced can be controlled without excessively introducing outside air more than necessary.

  In the rotary kiln according to the present invention, the kiln main body in which a heat-resistant caster is provided on the inner peripheral surface of a cylindrical steel plate is rotatably supported, and the end of the kiln main body is provided with a hood, The inlet hood on the processed material supply side is equipped with a burner for supplying hot air and the conveyor and pusher that are the processed material supply means, while the outlet hood on the processed material discharge side discharges the processed material after incineration and firing. And a discharge hopper for exhaust gas exhaust.

  The inlet hood and the outlet hood are provided with an annular sealing material fixing piece projecting along the outer peripheral surface of the kiln main body penetrating into the inlet hood and the outlet hood, and the front end portion of the sealing material fixing piece is prevented from entering outside air. As a sealing material, for example, a base end portion of a metal seal plate is fixed, and a free end portion of the seal plate is brought into contact with the outer peripheral surface of the kiln main body to be in contact with each other. In addition, the gap with the outlet hood is sealed.

  In addition, as an outside air introduction means for introducing outside air for cooling into a gap space formed by the outer peripheral surface of the kiln main body, the sealing material fixing piece, and the seal plate, a plurality of air sockets that communicate the gap space and the outside air are provided. Each air socket is detachably equipped with an air plug that blocks communication with outside air. Furthermore, the gap between the outer peripheral surface of the kiln main body and the sealing material fixing piece of the hood has a labyrinth structure so that the flow rate of the outside air introduced from the air socket can be sufficiently attenuated.

  When combustible waste such as waste wood or plastic is incinerated in the rotary kiln, or when firing various inorganic materials, first, the external air for cooling is changed according to the incineration / firing temperature of the processed material. The amount of introduction is determined, and an appropriate number of air plugs are removed from the air socket and opened accordingly. Then, the combustion operation of the burner is started, the kiln main body is rotated at a predetermined speed, and the processed material is supplied into the kiln main body by a conveyor, a pusher or the like. The processed material supplied into the kiln body flows down the kiln body to the downstream side according to the inclination while being exposed to the hot air from the burner, during which the temperature is raised to a desired temperature and incinerated or fired. The

  At this time, the end of the kiln main body that overlaps the seal material fixing piece or seal plate of the hood has little heat dissipation and heat is easily trapped, and the caster that is also provided around the inner peripheral surface of the seal material fixing piece for a long time. Since high temperature radiant heat is generated over the air, there is a concern that the steel plate and casters at the end of the kiln body adjacent to it may be adversely affected by deformation and damage due to thermal expansion, but the air with the air plug removed in advance The outside air for cooling is naturally sucked from the socket so as to be drawn by the gas flow in the kiln, and the labyrinth structure sufficiently attenuates the flow velocity, and is formed by the outer peripheral surface of the kiln body, the sealing material fixing piece, and the sealing plate. Because it is introduced into the hood through the gap space, the steel plate at the end of the kiln body that is exposed to this low-temperature outside air, the casters that are placed around the sealing material fixing piece, etc. Can be effectively cooling process, deformation of the steel sheet caused by thermal expansion, can be prevented caster damage, the flake off or the like.

  Moreover, introduction / non-introduction of outside air can be easily switched by attaching / detaching the air plug, and a flexible response such as appropriately performing a cooling process as required is possible. In addition, by providing a plurality of air sockets and air plugs, the amount of outside air introduced can be easily adjusted by adjusting the number of air plugs attached and detached, and a suitable cooling process according to the incineration / firing temperature of the processed material can be realized. . Furthermore, since the gap between the outer peripheral surface of the kiln main body and the sealing material fixing piece of the hood has a labyrinth structure, the flow rate of the outside air introduced from the air socket can be sufficiently attenuated in advance, and a large amount of air is introduced into the kiln when the outside air is introduced. The amount of outside air introduced can be controlled without the outside air being introduced vigorously.

  In this way, by providing outside air introduction means for introducing outside air for cooling into a gap space formed by the outer peripheral surface of the kiln body, the sealing material fixing piece, and the sealing material, the end of the kiln body is effectively cooled. And can be suitably protected.

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

  1 in the figure is a co-current type rotary kiln used for incineration of combustible waste such as waste wood and waste plastic, and for firing various inorganic materials. The kiln main body 3 is rotatably supported at an appropriate angle (for example, about 2 degrees), and can be rotated at an appropriate speed by a drive device (not shown) and an inverter (not shown). . The kiln main body 3 is provided with a heat-resistant caster 5 such as refractory bricks or ceramics around the inner peripheral surface of a cylindrical steel plate 4 to protect it from high-temperature hot air from a burner described later.

  A hood is provided at the end of the kiln body 3, and an inlet hood 6 on the supply side of the various processed products R is provided with a burner 7 for supplying hot air, a pusher 8 as a processed product supply means, and a supply hopper 9. On the other hand, the outlet hood 10 on the treated product discharge side is provided with a discharge hopper 11 that discharges the treated product R ′ that has been incinerated or baked, and an exhaust flue 12 for exhaust gas derivation. Downstream of the road 12, a chimney (not shown) is provided via a heat exchanger (not shown), a dust collector (not shown), an exhaust fan (not shown), and the like. Further, similarly to the kiln main body 3, heat-resistant casters 5 are respectively attached to the inner peripheral surfaces of the inlet hood 6 and the outlet hood 10 to protect them from high-temperature hot air. The outlet hood 10 has a structure in which the high-temperature exhaust gas G derived from the kiln main body 3 is led to the exhaust flue 12 over about 2 seconds or more, during which unburned matter and dioxins in the exhaust gas G are derived. And so on.

  The inlet hood 6 and the outlet hood 10 are provided with annular sealing material fixing pieces 13 and 14 projecting along the outer peripheral surface of the kiln main body 3 penetrating into the inlet hood 6 and the outlet hood 10. , 14, as a sealing material for preventing the entry of outside air, for example, a base end portion of a metal seal plate 15 is fixed, and the free end portion of the seal plate 15 is pressed against the outer peripheral surface of the kiln body 3. In this manner, the gap between the outer peripheral surface of the kiln body 3 and the inlet hood 6 and the outlet hood 10 is sealed so as to suppress the intrusion of outside air as much as possible without hindering the rotation of the kiln body 3. ing. A heat-resistant caster 5 is also provided around the inner peripheral surfaces of the sealing material fixing pieces 13 and 14 to protect them from high temperatures.

  In addition, an outside air introduction means for introducing outside air A for cooling into the substantially sealed gap space 16 formed by the outer peripheral surface of the kiln main body 3 and the sealing material fixing piece 14 of the outlet hood 10 and the seal plate 15. I have. For example, the outside air introduction means forms a concentric cylindrical outside air introduction passage 17 around the outer peripheral surface of the rear end portion of the kiln main body 3, and the rear end opening of the outside air introduction passage 17 is formed in the gap space 16. On the other hand, a plurality of air sockets 19 communicating the gap space 16 and the outside air through the outside air introduction path 17 are shown in the plate body 18 while the front end portion is closed by the plate body 18. As shown in FIG. 3, each air socket 19 is provided with an air plug 20 that detachably connects to the outside air so as to be detachable. Each air plug 20 can be easily attached to and detached from the air socket 19 with a tool such as a wrench.

  Further, the flow rate of the outside air A introduced from the air socket 19 can be sufficiently attenuated through the gap between the outer peripheral surface of the kiln main body 3 and the sealing material fixing piece 14 of the outlet hood 10 downstream of the outside air introduction path 17. In addition, as shown in FIG. 2, baffle plates 21 for collision with outside air are arranged in a staggered manner to form a labyrinth structure. In the gap between the outer peripheral surface of the kiln main body 3 and the sealing material fixing piece 13 of the inlet hood 6, the baffle plates 21 are similarly arranged in a staggered manner to form a labyrinth structure, which prevents excessive outside air from entering the kiln. I try to prevent it as much as possible.

  In the rotary kiln 3, for example, when combustible waste such as waste wood and waste plastic is incinerated, first, the dioxins are not synthesized during the incineration of the treated product R or burned even if synthesized. The amount of combustion of the burner 7 is adjusted so as to be decomposed so that the hot air temperature becomes about 800 ° C., and the outside air introduction required to cool the end of the kiln main body 3 that becomes high in accordance with this is introduced. The amount is determined, and an appropriate number (0 to all) of the air plugs 20 is removed from the air socket 19 and opened according to the determined amount of outside air introduced. Next, the combustion operation of the burner 7 is started, and the drive device is adjusted by an inverter to rotate the kiln main body 3 at an appropriate speed. The tilt angle and rotation speed of the kiln main body 3 are determined by, for example, taking the time required for the incineration process R to be completely incinerated in the hot air atmosphere, for example, about 30 to 40 minutes, and then the discharge hopper 11. Adjust each to reach

  Then, the processed product R in the supply hopper 9 is sequentially sent to the kiln main body 3 by the pusher 8 and supplied in the above operation state. The processed material R supplied into the kiln main body 3 gradually flows down in the kiln main body 3 according to the inclination while being exposed to high-temperature hot air of 800 ° C. or more from the burner 7, and incineration is performed during that time. The processed product R ′ finally subjected to the incineration process is discharged to the discharge hopper 11 at the lower end of the outlet hood 10 and stored. On the other hand, the high temperature exhaust gas G passes through the kiln main body 3 from the inlet hood 6 and is then led to the exhaust flue 12 by taking about 2 seconds or more at the outlet hood 10, and is included in the exhaust gas G during this time. Unburnt components and dioxins are decomposed by combustion.

  At this time, at the end of the kiln main body 3 which is covered with the sealing material fixing piece 14 and the sealing plate 15 of the outlet hood 10 as shown in FIG. 1 and FIG. The caster 5 which is easily provided and is also provided on the inner peripheral surface of the sealing material fixing piece 14 emits high-temperature radiant heat over a long period of time. Although there are concerns about adverse effects such as deformation and damage due to thermal expansion, ambient air A for cooling is drawn into the flow of exhaust gas G in the kiln from the air socket 19 that has been previously opened by removing the air plug 20. The air A is naturally sucked as it is, and the outside air A is blocked by a plurality of baffle plates 21 forming a labyrinth structure downstream of the outside air introduction path 17 and the flow velocity is greatly attenuated. Steel plate at the end of the kiln main body 3 that is directly exposed to the outside air A because it is introduced into the outlet hood 10 through the gap space 16 formed by the sealing member fixing piece 14 and the seal plate 15. 4 and the caster 5 provided around the sealing material fixing piece 14 can be effectively cooled, and can be protected by preventing deformation of the steel plate 4 due to thermal expansion, damage to the caster 5, peeling off, and the like. it can.

  The air plug 20 can be easily attached and detached manually with a tool such as a wrench, and the introduction or non-introduction of the outside air A for cooling is appropriately switched according to the treatment temperature or the like of the treatment object R, or the amount of outside air It is possible to respond flexibly by adjusting. Furthermore, since the gap between the outer peripheral surface of the kiln main body 3 and the sealing material fixing piece 14 of the outlet hood 10 has a labyrinth structure with a plurality of baffle plates 21, the flow rate of the outside air A introduced from the air socket 19 is sufficiently high in advance. The amount of outside air can be controlled without a large amount of outside air A being vigorously introduced into the kiln when the outside air is introduced.

  In this way, if the air plugs 20 are removed from the appropriate number of air sockets 19 according to the processing temperature of the processed material R and opened, an appropriate amount of cooling can be obtained so as to be drawn by the flow of the exhaust gas G in the kiln. The outside air A is naturally sucked, and the steel plate 4 and the casters 5 at the end of the kiln main body 3 can be effectively cooled and suitably protected.

  In addition, in the present Example, although the process thing R is described supposing the case where it incinerates this with a combustible waste, it does not limit to this at all, and a process thing is an inorganic material. In the case of firing treatment, it can be suitably used. In that case, the hot air temperature is adjusted by changing the combustion amount of the burner 7 in accordance with the firing treatment, and the tilt angle and rotation speed of the kiln body 3 are adjusted. In addition, after adjusting the processing time, the number of air plugs 20 attached and detached is adjusted according to the hot air temperature at the time of processing, the outside air amount A introduced from the air socket 19 is adjusted, and the end of the kiln main body 3 is suitably cooled. And protect.

  In the present embodiment, although the present invention is described in the rotary kiln 1 of the parallel flow system in which the flow direction of the processed material R and the exhaust gas G in the kiln main body 3 is the same, The present invention can also be suitably applied to a counterflow type rotary kiln in which the flow direction of the exhaust gas G is reversed.

It is a partially cutaway explanatory view showing an embodiment of a rotary kiln according to the present invention. It is a principal part enlarged view of FIG. FIG. 3 is a cross-sectional view taken along a line XX in FIG. FIG. 3 is a YY cross-sectional view in which a part of FIG. 2 is omitted.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Rotary kiln 3 ... Kiln main body 4 ... Steel plate 5 ... Caster 6 ... Inlet hood (hood) 7 ... Burner 8 ... Pusher 9 ... Supply hopper 10 ... Outlet hood (hood) 11 ... Discharge hopper 12 ... Exhaust flue 13, 14 ... Seal material fixing piece 15 ... Seal plate (seal material) 16 ... Clearance space 17 ... Outside air introduction path (outside air introduction means) 19 ... Air socket (outside air introduction means)
20 ... Air plug (outside air introducing means) 21 ... Baffle plate A ... Outside air for cooling G ... Exhaust gas R, R '... Processed material

Claims (3)

  In a rotary kiln in which a kiln main body provided with a heat-resistant caster on the inner peripheral surface of a cylindrical steel plate is rotatably supported, a hood provided at an end of the kiln main body along the outer peripheral surface of the kiln main body An annular sealing material fixing piece is protruded, and the base end portion of the sealing material for preventing the entry of outside air is fixed to the distal end portion of the sealing material fixing piece, while the free end portion of the sealing material is attached to the outer peripheral surface of the kiln body. A rotary kiln comprising an outside air introduction means for bringing the outside air for cooling into a gap space formed by the outer peripheral surface of the kiln main body, the sealing material fixing piece, and the sealing material.   2. The rotary kiln according to claim 1, further comprising an air socket that communicates the gap space and the outside air as outside air introduction means, and an air plug that blocks communication is detachably attached to the air socket.   The rotary kiln according to claim 1 or 2, wherein a gap between the outer peripheral surface of the kiln main body and the sealing material fixing piece of the hood has a labyrinth structure capable of attenuating the flow rate of the outside air introduced by the outside air introduction means.

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