WO2019187909A1 - Rotary kiln - Google Patents

Abstract

This rotary kiln is provided with: a barrel 10 that accommodates an object to be processed and can rotate around an axis; a heating means 11 for heating the object; and a supply means 12 for supplying the object into the barrel from an inlet provided on one end side of the barrel. A plurality of helical parts 20, standing from the inner circumferential surface of the barrel to a height lower than the inner radius and extending in a spiral shape in an axial direction of the barrel, are disposed at intervals inside the barrel, and flight plates 21 that are for stirring the object and stand from the inner circumferential surface of the barrel are disposed between the plurality of helical parts. The helical parts extend in a spiral shape in the direction in which the object flows toward the inlet due to forward rotation of the barrel, and a spiral path formed by the helical parts extending in the spiral shape is configured to be open rather than closed from one end to the other end thereof.

Description

Rotary kiln

The present invention relates to a rotary kiln, and more particularly to a rotary kiln having a structure in which a furnace is partitioned into a plurality of heating chambers.

Conventionally, rotary kilns have been used to perform heat treatment and the like on workpieces such as granules. The rotary kiln can be applied to various objects to be treated. For example, carbon nanotubes are generated by heat-treating catalytic metal particles together with hydrocarbon gas in the rotary kiln (for example, Patent Documents 1 to 3). Etc.).

The rotary kiln is usually tilted so that the inlet side into which the workpiece is introduced is higher than the outlet side where the workpiece is discharged in the cylinder (core tube) in which the workpiece is accommodated. The workpiece is configured to be transferred to the outlet side with the rotation of the cylinder. In order to uniformly heat the workpiece, it is necessary to increase the rotational speed of the cylinder to increase the movement of the workpiece. However, if the rotational speed of the cylinder is increased, the workpiece is processed. Since the speed which advances to the exit side of a cylinder becomes large, there exists a possibility that a to-be-processed object may be discharged | emitted out of a cylinder, without receiving sufficient heat processing. Furthermore, the filling rate of the object to be processed in the cylinder cannot be increased, and the processing efficiency cannot be improved.

In order to solve such a problem, Patent Document 4 discloses a rotary kiln configured so as not to promote the advancement of the workpiece to the outlet side even if the rotational speed of the cylinder is increased. The rotary kiln disclosed in Patent Document 4 includes a screw standing in a spiral shape from an inner peripheral surface of a cylindrical body and a stopper that closes a groove formed by the screw in a cylindrical body that accommodates an object to be processed. A closed screw is provided. Since the closed screw can dam the object to be processed, the movement of the object to be processed can be prevented and the filling rate of the object to be processed in the cylinder can be increased.

Special table 2013-518015 gazette JP 2011-116656 A JP 2006-516946 A JP 2016-121852 A

However, in the rotary kiln disclosed in Patent Document 4, in order to quickly discharge the entire amount of the processing object accommodated in the cylinder, the rotation of the cylinder is promoted in the same direction as the spiral direction of the closed screw. Even if it exists, since the advance of a to-be-processed object is prevented by the stopper of a closed screw, it cannot discharge quickly. It is also desired to further improve the processing efficiency by further increasing the filling rate of the object to be processed in the rotary kiln.

The present invention has been made in view of the above problems, and its purpose is to improve the processing efficiency of the object to be processed by improving the filling rate of the object to be processed, and to discharge the entire amount of the object to be processed. It is to be able to do it quickly and easily.

In order to achieve the above object, in the present invention, a plurality of helical helical portions are provided in the cylindrical body constituting the rotary kiln so that the object to be processed flows toward the inlet side of the cylindrical body by the normal rotation of the cylindrical body.

Specifically, the rotary kiln according to the present invention includes a cylindrical body that accommodates an object to be processed and is rotatable around an axis, a heating unit for heat-treating the object to be processed, and the object to be processed. A rotary kiln having a supply means for supplying into the cylinder from an inlet provided at one end of the cylinder, and standing in the cylinder at a height less than the inner radius from the inner peripheral surface of the cylinder. A plurality of helical portions extending in a spiral shape in the axial direction of the cylindrical body with a gap between each other, and between the plurality of helical portions, the cylindrical portion is erected from an inner peripheral surface of the cylindrical body A flight plate for agitating the object to be processed is disposed, and the helical portion extends in a spiral shape in a direction in which the object to be processed flows toward the inlet side by the positive rotation of the cylindrical body. Defined by the extending helical part and the inner peripheral surface of the cylinder Helical path is characterized by being configured to communicate without being closed from one end to the other.

According to the rotary kiln according to the present invention, the helical portion extends in a spiral shape in a direction in which the object to be processed flows toward the inlet side of the cylinder by the normal rotation of the cylinder. Along with this, the helical part is guided to the inlet side of the cylindrical body. Therefore, it can suppress that a to-be-processed object advances to the exit side of a cylinder, and can improve the filling rate of the to-be-processed object in a cylinder. In addition, since a plurality of helical portions are arranged with a gap therebetween, the cylindrical body has a structure divided into a plurality of heating chambers by the helical portion. For this reason, the object to be processed is sequentially transferred from the heating chamber on the inlet side of the cylinder to the heating chamber on the outlet side. However, as described above, the object to be processed advances to the outlet side of the cylinder. Therefore, the object to be processed is prevented from being transferred to the next heating chamber. Therefore, after the amount of the object to be processed in the heating chamber is accumulated up to the height of the helical portion, it is transferred to the next heating chamber by overflow. Since this process is sequentially performed in each heating chamber, the filling rate of the object to be processed in each heating chamber can be increased, and as a result, the filling rate of the object to be processed in the cylinder can be further improved. Processing efficiency can be improved. In addition, since the spiral passage formed by the helical portion is configured to communicate from one end to the other end without being closed, the helical portion and the inner peripheral surface of the cylindrical body are rotated by rotating the cylindrical body in reverse. The entire amount of the object to be processed in the cylinder can be quickly discharged along the defined spiral passage.

In the rotary kiln according to the present invention, it is preferable that each of the plurality of helical portions is formed with a length that makes two to three rounds of the inner circumferential surface of the cylindrical body.

By setting the helical part to two or more rounds, it is possible to efficiently prevent the object to be processed, which is advanced by the stirring action by the rotation of the furnace without being overflowed, from being transferred to the next heating chamber. Specifically, the object to be processed moves forward with repeated rotation of the furnace as it is lifted to the upper part of the furnace and then drops downward. At that time, the object to be processed falls into the helical passage of the helical part. By doing so, it is returned to the inlet side by the flow in the spiral passage by the forward rotation of the furnace. When the helical part is formed in about one turn, a spiral passage showing such an effect cannot be formed. Therefore, in order to effectively prevent transfer of the workpiece to the next heating chamber, the helical part is It is preferable that it is formed in two weeks or more. On the other hand, if the helical portion exceeds three turns, the effect of suppressing the advance of the workpiece is hardly improved. In addition, by making the helical portion from two to three rounds, the length of the helical portion is not excessively long, and a sufficient volume of the plurality of heating chambers partitioned by the plurality of helical portions can be secured. Furthermore, the helical path defined by the helical portion and the inner peripheral surface of the cylinder can secure a sufficient length, the forward movement of the object to be processed by the normal rotation of the cylinder, and the process by the reverse rotation of the cylinder It is possible to sufficiently achieve the effect of quick discharge of objects. Further, the spiral passage communicated without being closed is not hindered from quickly discharging the object to be processed by the reverse rotation of the cylinder.

The rotary kiln according to the present invention preferably further includes a gas introduction means for introducing gas to the inlet side of the cylinder. The gas introduction means may be configured to introduce gas from the inlet side of the cylinder, for example, or may be configured to introduce gas to the inlet side of the cylinder by a gas supply pipe extending from the outlet of the cylinder to the inlet side. .

In this way, the object to be processed easily comes into contact with the gas on the inlet side of the cylinder, and the rotary kiln of the present invention is configured to suppress the advance of the object to be processed to the outlet side as described above. Contact efficiency between the object to be processed and the gas can be improved. Therefore, when it is intended to react not only the heat treatment but also a predetermined gas to the object to be treated, this configuration can improve the reaction efficiency between the object to be treated and the gas.

The rotary kiln according to the present invention is preferably provided with means for suppressing adhesion of an object to be processed to the cylinder. Examples of the means include an air knocker and a knocker that strikes a tubular body or a flight plate erected from the inner peripheral surface of the tubular body according to the rotation during the rotary kiln operation. The installation location of the knocker is not particularly limited, but it is more preferable to install the knocker inside the rotary kiln because it can effectively suppress adhesion of the object to be processed.

Further, in the rotary kiln according to the present invention, the cylindrical body may be inclined and arranged.

In the rotary kiln according to the present invention, the gas contains 50% or more of hydrocarbon gas, and the object to be processed contains catalytic metal particles for decomposing the hydrocarbon gas into carbon and hydrogen, and the nanocarbon It is preferably used to produce material and hydrogen. The nanocarbon material includes carbon nanotubes or graphene. In order to produce the nanocarbon material and hydrogen, the gas introduced into the rotary kiln according to the present invention preferably does not contain nitrogen. This is because nitrogen gas reacts with hydrogen at a high temperature to generate ammonia gas to deactivate the catalyst metal particles.

In this case, the catalytic metal particles as the object to be treated and the hydrocarbon gas come into contact with each other in the heated cylinder and react to decompose the hydrocarbons so that the carbon atoms are taken into the catalytic metal particles and move and diffuse. Hydrogen is generated. Thereafter, supersaturated carbon atoms are deposited on the catalyst metal particles, and deposition proceeds. As a result, the object to be treated after the reaction becomes bulky and its density decreases, so that the object to be treated is located near the center of the rotating cylinder and is easily transferred to the next heating chamber due to overflow. Become. On the other hand, the object whose reaction has not progressed sufficiently is located in the vicinity of the inner peripheral surface of the cylindrical body due to its small volume and high density, and the forward movement is suppressed by the flow in the helical passage of the helical part. Or returned from the heating chamber on the outlet side to the heating chamber on the inlet side. Therefore, since the processed object to which the reaction has progressed can be preferentially transferred to the outlet side, the processing efficiency of the processed object can be improved and the processed object can be processed uniformly.

The rotary kiln according to the present invention can improve the filling rate of the object to be processed, and therefore can improve the processing efficiency of the object to be processed. Furthermore, discharge of the entire amount of the processing object outside the rotary kiln can be performed quickly and easily.

It is sectional drawing which shows the whole structure of the rotary kiln which concerns on one Embodiment of this invention. It is the schematic which shows the internal structure of the cylinder of the rotary kiln which concerns on one Embodiment of this invention. It is a front view which shows the entrance side of the cylinder of the rotary kiln which concerns on one Embodiment of this invention. FIG. 3 is a cross-sectional perspective view taken along the line AA of FIG. 2, showing an inlet side of a cylindrical body of a rotary kiln according to an embodiment of the present invention. It is a figure which shows the shape of the helical part arrange | positioned in the cylinder of the rotary kiln which concerns on one Embodiment of this invention. It is a figure for demonstrating operation | movement of the knocker provided in the rotary kiln which concerns on one Embodiment of this invention.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The following description of the preferred embodiments is merely exemplary in nature and is not intended to limit the invention, its method of application, or its application.

First, an overall configuration of a rotary kiln according to an embodiment of the present invention will be described with reference to FIG. As shown in FIG. 1, the rotary kiln according to the present embodiment includes a cylinder 10 that is a furnace core tube for accommodating and heat-treating an object to be processed (in FIG. 1, the internal structure of the cylinder 10 is omitted), A heater 11 as a heating means for heating the cylinder 10 and a feeder 12 as a supply means for supplying an object to be processed from the inlet of the cylinder are provided. The heater 11 is provided in a heat insulating cover 11 a that covers the outside of the cylindrical body 10. Furthermore, the rotary kiln according to the present embodiment includes a tire 13 provided on the outer periphery of the cylindrical body on the inlet 10a side and the outlet 10b side, and a roller 14 that is connected to the tire 13 so that the tire 13 can rotate. . When the tire 13 is rotated by the rotation of the roller 14, the cylinder 10 is configured to be rotatable around its own axis (with the longitudinal direction as an axis) in a desired direction (forward rotation or reverse rotation).

Also, the rotary kiln according to the present embodiment is provided with a gas supply pipe 15 for supplying gas into the cylinder 10 on the inlet 10a side of the cylinder 10. 1 shows a form in which the gas supply pipe 15 extends from the inlet side of the cylinder, for example, a form in which a gas supply pipe extending from the outlet 10b of the cylinder 10 to the inlet 10a side is provided. It doesn't matter. Further, a fixed end (shaft seal cover) 16a covering the inlet 10a is provided on the inlet 10a side of the cylindrical body 10, and the feeder 12 and the gas supply pipe 15 penetrate the fixed end 16a and enter the cylindrical body 10. It extends to. Similarly to the inlet 10a, a fixed end (shaft seal cover) 16b that covers the outlet 10b is also provided on the outlet 10b side of the cylindrical body 10. Further, on the outlet 10b side of the cylindrical body 10, there is provided a storage portion 17 that communicates with the internal space of the fixed end 16b and stores an object processed in the cylindrical body 10 discharged from the outlet 10b. ing. Similarly, on the outlet 10b side of the cylindrical body 10, there is provided a gas exhaust port 18 that communicates with the internal space of the fixed end 16b and exhausts the gas generated in the cylindrical body 10, and this gas exhaust port is provided. A filter 19 for trapping fine particles other than gas is provided at the outlet.

Next, the structure inside the cylinder will be described with reference to FIGS. As shown in FIGS. 2 to 4, a plurality of helical portions 20 are arranged in the cylindrical body 10 so as to stand in the center direction from the inner circumferential surface (in FIG. The unit 20 is shown in a simplified manner.) Specifically, each of the plurality of helical portions 20 has a shape extending spirally in the axial direction of the cylindrical body 10 (see FIG. 5), and is disposed with a gap in the axial direction of the cylindrical body 10. The spiral direction of the helical portion 20 is configured to be opposite to the normal rotation of the cylindrical body 10, and is configured to have a spiral number of turns of about two. As shown in FIG. 4, a spiral passage 25 defined by the helical portion 20 and the inner peripheral surface of the cylindrical body 10 is formed by the spiral helical portion 20. As shown in FIGS. 3 and 4, the helical portion 20 is erected from the inner peripheral surface of the cylindrical body at a height less than the inner radius, so that the vicinity of the center of the cylindrical body 10 is the axis of the cylindrical body. Opening in the direction (longitudinal direction).

Further, as shown in FIG. 2, the space in the cylinder 10 is divided into a plurality of heating chambers 30 by the plurality of helical portions 20. Here, the first helical portion 20a, the second helical portion 20b, and the third helical portion 20c are sequentially called from the helical portion on the inlet 10a side of the cylindrical body 10, and sequentially from the heating chamber on the inlet 10a side of the cylindrical body 10, These are referred to as 1 heating chamber 30a, 2nd heating chamber 30b, 3rd heating chamber 30c and 4th heating chamber 30d.

Between the plurality of helical portions 20, a flight plate 21 erected in the center direction from the inner peripheral surface of the cylinder 10 is disposed. The flight plate 21 rakes up and stirs the object to be processed filled in the cylinder 10 as the cylinder 10 rotates. Thereby, the heat treatment of the object to be processed and the contact with the gas supplied from the gas supply pipe 15 can be made uniform.

Next, the processing process of the to-be-processed object using the rotary kiln which concerns on this embodiment is demonstrated. First, the workpiece is supplied into the cylinder 10 by the feeder 12, and specifically, the workpiece is supplied to the first heating chamber 30 a in the cylinder 10. The inside of the cylinder 10 is heated to a desired temperature by the heater 11, and the cylinder 10 is rotated forward by the tire 13 and the roller 14. Thus, the object to be processed is heat-treated while being stirred by the flight plate 21 in the first heating chamber 30a. In addition, when making it react with desired gas with heat processing with respect to a to-be-processed object, such gas is supplied in the cylinder 10 from the gas supply pipe | tube 15. FIG.

While the object to be processed is supplied from the feeder 12 and the amount of the object to be processed in the first heating chamber 30a is increased, the object to be processed advances toward the outlet 10b, but is blocked by the first helical part 20a. . Further, even when a workpiece is further supplied and the workpiece enters the spiral passage 25 defined by the first helical portion 20a and the inner peripheral surface of the cylindrical body 10, the first helical portion 20a Is formed in a spiral shape that circulates in a direction opposite to the forward rotation of the cylindrical body 10, that is, since the passage 25 is also formed in a spiral shape in the same direction, the object to be processed is guided in the direction of the inlet 10a. Will be.

However, when the object to be processed is further supplied to the first heating chamber 30a, an overflow occurs in the passage 25 of the first heating chamber 30a and the first helical portion 20a, and passes through the central opening of the first helical portion 20a. Thus, the object to be processed is transferred to the second heating chamber 30b adjacent to the first heating chamber 30a. Thereafter, according to the further supply of the object to be processed from the feeder 12, the object to be processed is transferred from the first heating chamber 30a to the second heating chamber 30b. The transfer of the object to be processed from the heating chamber 30c and the third heating chamber 30c to the fourth heating chamber 30d proceeds sequentially. Then, the object to be processed is discharged from the cylindrical body 10 through the outlet 10b from the fourth heating chamber 30d closest to the outlet 10b side and sent to the storage unit 17.

As described above, the rotary kiln according to the present embodiment is configured to return the object to be processed to the inlet 10a side of the cylindrical body 10, and the next heating after the object to be processed is sufficiently filled in each heating chamber. It is configured to be transferred to the room. Therefore, the filling rate of the object to be processed in the cylinder 10 can be improved, and the processing efficiency for the object to be processed can be improved.

Moreover, in the rotary kiln according to the present embodiment, when it is desired to quickly discharge the entire amount of the processing object filled in the cylinder 10 from the outlet 10b, it can be realized by rotating the cylinder 10 in the reverse direction. As described above, since the helical portion 20 has a spiral shape that circulates in the direction opposite to the forward rotation of the cylindrical body 10, the helical passage 25 defined by the helical portion 20 and the inner peripheral surface of the cylindrical body 10. This is because the object to be processed is promoted to advance in the direction of the outlet 10b according to the passage 25 by rotating the cylinder 10 in the reverse direction.

Further, in the rotary kiln according to the present embodiment, as shown in FIG. 2, a knocker 40 is provided in the cylinder body 10 for suppressing the adhesion of the object to be processed into the cylinder body 10. The knocker 40 is configured to strike, for example, the flight plate 21 in the cylinder 10 in accordance with the rotation of the cylinder 10. Specifically, the knocker shaft 41 fixed to the fixed end 16a on the inlet 10 side of the cylindrical body 10 is rotatably attached with the knocker shaft 41 as an axis. The knocker shaft 41 is provided at a position shifted from the axial center of the cylindrical body 10.

The operation of the knocker 40 will be described with reference to FIG. FIG. 6 shows an example in which the knocker shaft 41 is arranged to be shifted to the left side from the axial center of the cylinder 10, and the two-dot chain line circle in FIG. 6 represents the knocker 40 rotating around the knocker shaft 41. Indicates the trajectory through which the tip passes. The broken lines indicate the positions of the knocker 40 and the flight plate 21 that rotate as the cylinder 10 rotates.

First, as shown by the solid line, the knocker 40 is disposed below (at 6 o'clock) and is pushed by the flight plate 21 along with the clockwise rotation of the cylinder 10 to the left (at 9 o'clock). It rotates with the knocker shaft 41 as an axis. Then, as the cylinder 10 is rotated, it is pushed by the flight plate 21 and rises upward (position at 12 o'clock). After that, when the knocker rotates from 1 o'clock to 2 o'clock, the knocker shaft 41 becomes cylindrical. The knocker 40 moves away from the flight plate 21, vigorously rotates clockwise by gravity, and strikes the other flight plate 21. By this impact, the object to be processed that adheres to the cylindrical body 10 can be removed. Then, it returns to the 6 o'clock position again and the above process is repeated.

Here, the configuration in which the knocker 40 is rotatably attached to the knocker shaft 41 is shown. However, for example, the gas supply pipe 15 is arranged so as to be offset from the axial center of the cylindrical body 10, and the gas supply pipe 15 is pivoted. You may attach the knocker 40 so that rotation is possible as a core. In this way, the knocker shaft 41 is not required separately, and an increase in the number of parts can be prevented. Here, the knocker is provided inside the cylinder 10, but the present invention is not limited to this, and the knocker may be provided outside the cylinder 10.

As described above, according to the rotary kiln according to the present embodiment, it is possible to improve the processing efficiency of the object to be processed because the filling rate of the object to be processed can be improved, and further, discharge of the entire amount of the object to be processed outside the rotary kiln. It is extremely useful because it can be made quickly and easily.

Next, a case where the rotary kiln according to the present embodiment is used for generating carbon nanotubes by a chemical vapor deposition (CVD) method will be described. In the CVD method, hydrocarbon gas and catalytic metal particles are supplied into the heating chamber 30, the hydrocarbon gas is decomposed into carbon and hydrogen by the catalyst and heating, and carbon atoms are taken into the catalytic metal particles, Move and diffuse. Thereafter, carbon is deposited by being supersaturated, and carbon nanotubes are generated by being deposited. Therefore, in this case, catalytic metal particles for decomposing the hydrocarbon gas into carbon and hydrogen are used as the object to be treated, and a gas containing 50% or more of the hydrocarbon gas as the gas supplied from the gas supply pipe 15 (hereinafter referred to as the gas to be treated) Called hydrocarbon gas).

The process will be described specifically. First, the cylinder 10 is heated by the heater 11, and a hydrocarbon gas is supplied into the cylinder 10 from the gas supply pipe 15. Thereafter, the catalyst metal particles are supplied by the feeder 12 into the cylindrical body 10, specifically, the first heating chamber 30a. The supplied catalytic metal particles take in carbon atoms while being stirred by the flight plate 21 together with the forward rotation of the cylinder 10, and carbon starts to precipitate in the catalytic metal particles by the above mechanism. As the reaction proceeds further, carbon deposition proceeds, and as a result, carbon nanotubes are generated. Therefore, in the first heating chamber 30a, the catalyst metal particles that have been reacted and deposited on the carbon nanotubes and the catalyst metal particles that have been supplied from the feeder 12 and have not yet reacted and have no carbon deposition are mixed. Further, even catalyst metal particles that have reacted with the gas are mixed with catalyst metal particles having different degrees of reactivity. As described above, when the supply of catalyst metal particles from the feeder 12 to the first heating chamber 30a proceeds, overflow occurs in the first heating chamber 30a. At this time, unreacted or low-reactivity catalyst metal particles are small in volume and large in density, while high-reactivity catalyst metal particles deposited on carbon nanotubes are large in volume and small in density. The catalyst metal particles having a low value sink to the inner peripheral surface side of the cylindrical body 10, while the catalyst metal particles having a high reactivity are distributed so as to be exposed to the center side of the cylindrical body 10. As a result, the catalytic metal particles that have undergone the reaction are preferentially transferred to the second heating chamber 30b through the opening at the center of the first helical 20a due to overflow.

Thereafter, according to the further supply of the catalyst metal particles from the feeder 12, the transfer of the catalyst metal particles from the first heating chamber 30a to the second heating chamber 30b also proceeds, and the third heating chamber 30b to the third heating chamber 30b in the same manner. The catalyst metal particles are sequentially transferred from the heating chamber 30c and the third heating chamber 30c to the fourth heating chamber 30d. Then, the catalytic metal particles are discharged from the fourth heating chamber 30d closest to the outlet 10b side through the outlet 10b, and are discharged to the storage unit 17 from the cylindrical body 10. As described above, unreacted or low-reactivity catalytic metal particles sink to the inner peripheral surface side of the cylindrical body 10, while high-reactive catalytic metal particles are exposed to the center side of the cylindrical body 10. Therefore, the catalyst metal particles in which the reaction is proceeding are preferentially carried out from the second heating chamber 30b to the third heating chamber 30c and from the third heating chamber 30c to the fourth heating chamber 30d. Further, hydrogen generated together with the carbon nanotube is discharged from the gas discharge port 18 to the outside of the cylindrical body.

When unreacted catalyst metal particles are transferred from the first heating chamber 30a to the second heating chamber 30b, the unreacted or low-reactivity catalyst metal particles are located on the inner peripheral surface side of the cylindrical body 10 as described above. Since it is distributed so that it sinks, it returns preferentially to the 1st heating chamber 30a through the spiral passage 25 defined by the 1st helical part 20a and the inner skin of cylinder 10 according to the normal rotation of cylinder 10. It will be. Similarly, in the third heating chamber 30c and the fourth heating chamber 30d, unreacted or low-reactivity catalytic metal particles are returned to the heating chamber on the inlet 10a side. In the present embodiment, since the hydrocarbon gas is supplied from the gas supply pipe 15 to the first heating chamber 30a, the heating chamber on the inlet 10a side, particularly the first heating chamber 30a, becomes an environment that easily reacts with the hydrocarbon gas. Therefore, returning the unreacted or low-reactivity catalytic metal particles to the heating chamber on the inlet 10a side allows the catalytic metal particles to react uniformly and efficiently obtain carbon nanotubes. . Further, in the present embodiment, the catalyst metal particles move forward while repeatedly falling down after being lifted to the upper part of the cylindrical body 10 along with the rotation of the cylindrical body 10, but at that time, the inner peripheral surface of the cylindrical body 10 Stirring is performed so that the unreacted or low-reactivity catalyst metal particles that have settled on the side are exposed to the center side of the cylinder 10. For this reason, the contact property with the hydrocarbon gas of the catalyst metal particle of unreacted or low reactivity is improved, and a catalyst metal particle can be made to react uniformly.

As described above, when the rotary kiln according to the present embodiment is used for the production of carbon nanotubes by the CVD method, it is possible to preferentially transfer the object to be processed to the outlet side of the cylinder, and the unreacted or the reactivity is low. A low workpiece can be returned to the inlet side of the cylinder. For this reason, the processing efficiency of a to-be-processed object can be improved, and a to-be-processed object can be processed uniformly. In addition, although the catalytic metal particle which produces | generates a carbon nanotube and hydrogen was illustrated here as a to-be-processed object, if a to-be-processed object becomes bulky and a density becomes small as reaction of a to-be-processed object progresses, the same It is possible to obtain the effect.

In the present embodiment, gas is supplied into the cylinder 10 from the inlet 10a side of the cylinder 10 by the gas supply pipe 15, but in addition to this, from the outlet 10b side of the cylinder 10 and the center of the cylinder 10 You may supply gas also from a part. Further, the supplied gas may be heated to a predetermined temperature in advance. In the present embodiment, three helical portions 20 are formed and the heating chamber 30 is divided into four. However, the present invention is not limited to this, and the number of the helical portions 20 may be two or four or more. . Moreover, in this embodiment, although the frequency | count of the spiral helical part 20 was set to about 2 times, it is not restricted to this. However, in order to ensure a sufficient volume of the heating chamber, it is preferable to have three or less turns, and in order to ensure a sufficiently long spiral passage 25, it is preferable to have two or more turns.

10 Tube (core tube)
11 Heater (heating means)
12 Feeder (supply means)
13 Tire 14 Roller 15 Gas supply pipe 16a, b Shaft seal cover (fixed end)
17 Reservoir 18 Gas outlet 19 Filter 20 Helical part 21 Flight plate 25 Passage 30 Heating chamber 40 Knocker 41 Knocker shaft

Claims (4)

A cylinder that accommodates the object to be processed and is rotatable about an axis, heating means for heat-treating the object to be processed, and the cylinder from an inlet provided on one end side of the cylinder A rotary kiln equipped with a supply means for supplying into the body,
In the cylindrical body, a plurality of helical portions that are erected from the inner peripheral surface of the cylindrical body at a height less than the inner radius and extend spirally in the axial direction of the cylindrical body are arranged with a gap therebetween,
Between the plurality of helical portions, a flight plate for agitating the object to be processed which is erected from the inner peripheral surface of the cylindrical body is disposed,
The helical portion extends in a spiral shape in a direction in which the object to be processed flows to the inlet side by the positive rotation of the cylindrical body,
A rotary kiln characterized in that a helical passage defined by the helically extending helical portion and the inner peripheral surface of the cylindrical body communicates without being closed from one end to the other end. 2. The rotary kiln according to claim 1, wherein each of the plurality of helical portions is formed with a length that makes two to three rounds of the inner circumferential surface of the cylindrical body. The rotary kiln according to claim 1 or 2, further comprising gas introduction means for introducing gas into the inlet side of the cylindrical body. The gas contains a hydrocarbon gas of 50% or more, and the object to be processed contains catalytic metal particles for decomposing the hydrocarbon gas into carbon and hydrogen, and generates a nanocarbon material and hydrogen. The rotary kiln according to claim 3, wherein the rotary kiln is used.

Images