Rotary Kiln

Abstract

To provide a rotary kiln allowing a treatment object to be easily subjected to uniform heat treatment.SOLUTION: A rotary kiln 1 has an external cylinder 20 and an inner cylinder 22 having a heat treatment zone B. The inner cylinder 22 has an inner cylinder body 220 and a spiral downstream feeding fin 222 placed downstream from an axial directional center C of the heat treatment zone B. A treatment object W is fed in the approaching direction to the heat treatment zone B in a normal rotation of the inner cylinder 22, and in the separating direction from the heat treatment zone B in a reverse rotation of the inner cylinder 22, by the downstream feeding fin 222. The inner cylinder 22 is normally rotated in a heat treatment mode, the inner cylinder 22 is normally rotated and inclined in a bias mode, and the inner cylinder 22 is reversely rotated in a discharge mode.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a rotary kiln that performs heat treatment on objects to be treated, such as pharmaceuticals and battery materials. [Background technology]

[0002] Patent Document 1 discloses a rotary kiln capable of batch processing (batch-type heat treatment). The rotary kiln described in the document includes an outer cylinder and an inner cylinder. The outer cylinder and the inner cylinder are arranged coaxially. The outer cylinder and the inner cylinder are set with a predetermined inclination that descends from the upstream side to the downstream side. The inclination is constant. The outer cylinder and the inner cylinder are rotatable around the axis in both forward and reverse directions. A heat treatment zone is set inside the inner cylinder in which the workpiece is subjected to heat treatment. A return blade is arranged on the inner peripheral surface at the downstream end of the inner cylinder. The return blade extends in a spiral shape.

[0003] When performing batch processing, the inner cylinder is rotated in the forward direction. The return blades prevent the material from flowing out of the inner cylinder. When discharging the material, the inner cylinder is rotated in the reverse direction. The return blades assist the material to be treated to be discharged from the inner cylinder. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2010-38508 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the case of the rotary kiln described in the document, the inclination of the inner cylinder is constant. Moreover, the inclination is set to be large in consideration of the dischargeability of the material to be treated. Therefore, when performing batch processing, the material to be treated tends to flow down from the upstream side to the downstream side due to its own weight. Therefore, the material to be treated tends to be unevenly distributed near the downstream end of the inner cylinder. Therefore, it is difficult to perform a uniform heat treatment on the material to be treated. Therefore, an object of the present invention is to provide a rotary kiln that makes it easy to perform a uniform heat treatment on the material to be treated. [Means for solving the problem]

[0006] In order to solve the above problems, the rotary kiln of the present invention is a rotary kiln including an outer cylinder rotatable in a forward and reverse direction around its own axis, and an inner cylinder arranged radially inside the outer cylinder, rotatable together with the outer cylinder, and having a heat treatment zone therein for subjecting a workpiece to heat treatment, wherein the inner cylinder has a cylindrical inner cylinder body, and a spiral downstream feed fin arranged on the inner peripheral surface of the inner cylinder body downstream of the axial center of the heat treatment zone, When the inner tube rotates in the forward direction, the workpiece is fed by the downstream feed fin in a direction approaching the heat treatment zone, and when the inner tube rotates in the reverse direction, the workpiece is fed by the downstream feed fin in a direction away from the heat treatment zone. In a heat treatment mode in which the workpiece is subjected to heat treatment, the inner tube is rotated in the forward direction, the workpiece is retained in the heat treatment zone, and the heat treatment is performed on the workpiece. In a shifting mode in which the workpiece is moved downstream, the inner tube is rotated in the forward direction and tilted so that the downward slope from the upstream side to the downstream side becomes larger than in the heat treatment mode, and the workpiece is moved downstream in the heat treatment zone. In a discharge mode in which the workpiece is discharged, the inner tube is rotated in the reverse direction and the workpiece is moved downstream from the heat treatment zone.

[0007] Here, the "upstream side" refers to the side of the inner cylinder in the axial direction to which the material to be treated is supplied, and the "downstream side" refers to the side of the inner cylinder in the axial direction opposite to the "upstream side" and from which the material to be treated is discharged. Effect of the Invention

[0008] The inner cylinder of the rotary kiln of the present invention has downstream feed fins, which feed the workpieces in a heat treatment mode in a direction approaching the heat treatment zone, thereby allowing the workpieces to be subjected to batch treatment.

[0009] In addition, the inner cylinder of the rotary kiln of the present invention is tiltable. The inclination of the inner cylinder in the heat treatment mode (including 0 (horizontal)) is smaller than the inclination of the inner cylinder in the discharge mode. Therefore, in the heat treatment mode, it is possible to prevent the material to be treated from being unevenly distributed on the downstream side of the heat treatment zone. This makes it easier to apply a uniform heat treatment to the material to be treated. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is an axial cross-sectional view of a rotary kiln according to one embodiment of the present invention. [Diagram 2] FIG. 2 is an enlarged view of the area within box II in FIG. [Diagram 3] FIG. 3 is a cross-sectional view taken along line III-III of FIG. [Figure 4] FIG. 4 is an enlarged view of the area within box IV in FIG. [Diagram 5] FIG. 5 is a partial axial cross-sectional view of the rotary kiln in a side-loading mode. [Figure 6] FIG. 6 is a partial axial cross-sectional view of the rotary kiln in the discharge mode. [Figure 7] FIG. 7 is a partial axial cross-sectional view of the rotary kiln before the inner cylinder is attached. [Figure 8] 8(A) to 8(E) are developments of the inner circumferential surface of the inner cylinder body of the rotary kiln according to other embodiments (Nos. 1 to 5). [Figure 9] 9(A) to 9(D) are radial cross-sectional views of the inner cylinder body of the rotary kiln according to other embodiments (Nos. 6 to 9). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the rotary kiln of the present invention will be described.

[0012] [Configuration of a rotary kiln] First, the configuration of the rotary kiln of this embodiment will be described. In the following figures, the left side corresponds to the upstream side (supply side), and the right side corresponds to the downstream side (discharge side). FIG. 1 shows an axial cross-sectional view of the rotary kiln of this embodiment. FIG. 2 shows an enlarged view of the area in frame II of FIG. 1. FIG. 3 shows a cross-sectional view in the III-III direction of FIG. 2. FIG. 4 shows an enlarged view of the area in frame IV of FIG. 2. FIG. 2 shows a partial axial cross-sectional view of the rotary kiln in the heat treatment mode. As shown in FIGS. 1 to 4, the rotary kiln 1 mainly includes a rotating cylinder section 2, a rotation support section 3, a supply section 4, a heat treatment section 5, a discharge section 6, and a stand 9.

[0013] (Frame 9) The stand 9 includes a lower frame 93, an upper frame 94, a tilting shaft 95, and a lift adjustment unit 96. The lower frame 93 is included in the concept of the "base" of the present invention. The upper frame 94 is included in the concept of the "tilting unit" of the present invention.

[0014] The upper frame 94 is disposed above the lower frame 93, facing the same at a predetermined distance. The tilt shaft 95 and the elevation adjustment unit 96 are disposed between the upper frame 94 and the lower frame 93. The upper frame 94 is capable of tilting about the tilt shaft 95 relative to the lower frame 93 by the driving force of the elevation adjustment unit 96.

[0015] (Rotational support part 3) The rotation support part 3 is disposed on the upper frame 94. The rotation support part 3 includes a pair of upstream rollers 30, a pair of downstream rollers 31, an upstream sliding seal part 32, and a downstream sliding seal part 33. The upstream roller 30 is disposed on the left side of the heat treatment part 5 described later. The pair of upstream rollers 30 are disposed side by side in the front-rear direction (furnace width direction). The downstream roller 31 is disposed on the right side of the heat treatment part 5. The pair of downstream rollers 31 are disposed side by side in the front-rear direction. The upstream sliding seal part 32 is disposed on the left side of the upstream roller 30. The downstream sliding seal part 33 is disposed on the right side of the downstream roller 31.

[0016] (Rotating cylinder part 2) The rotating cylinder portion 2 is rotatably supported by a rotation support portion 3. The rotating cylinder portion 2 includes an outer cylinder 20, a connecting cylinder 21, and an inner cylinder 22. The outer cylinder 20 includes an outer cylinder main body 200, an upstream tire 201, a downstream tire 202, and a sprocket 203.

[0017] The outer cylinder body 200 has a cylindrical shape centered on the rotation axis A. The inner peripheral surface of the outer cylinder body 200 is a smooth surface without unevenness. The outer cylinder body 200 extends in the left-right direction at an inclination angle (specifically, the inclination angle with respect to the left-right direction (horizontal direction). For example, "the inclination angle becomes larger" means that the inclination from the left side (upstream side) to the right side (downstream side) with respect to the horizontal direction becomes larger. The same applies below) of 0°. As shown in FIG. 4, a mounting hole 200a is opened at the right end of the outer cylinder body 200. The vicinity of the right end of the outer cylinder body 200 (the portion to the left of the mounting hole 200a) is in sliding contact with the downstream sliding seal portion 33. More specifically, as shown in FIG. 4, the downstream sliding seal portion 33 is provided with a pair of left and right bearings 330. The outer cylinder body 200 is in sliding contact with the downstream sliding seal portion 33 via the bearings 330.

[0018] The upstream tire 201 is mounted around the left end of the outer cylinder body 200. The upstream tire 201 has an annular shape. The upstream tire 201 is rotatably mounted on a pair of upstream rollers 30. The downstream tire 202 is mounted around the right end of the outer cylinder body 200. The downstream tire 202 has an annular shape. The downstream tire 202 is rotatably mounted on a pair of downstream rollers 31.

[0019] The sprocket 203 is provided adjacent to the left side of the upstream tire 201. A chain (not shown) for transmitting driving force is wound around the sprocket 203. Driving force from a driving device (not shown) is transmitted to the sprocket 203 via the chain. The driving force enables the outer cylinder body 200, i.e., the outer cylinder 20, to rotate on the upstream roller 30 and the downstream roller 31 in the forward and reverse directions (opposite to the forward direction) around the rotation axis A (the radial center axis of the outer cylinder body 200).

[0020] The connecting tube 21 is connected to the left side of the outer tube main body 200. The connecting tube 21 has a cylindrical shape centered on the rotation axis A. The connecting tube 21 is in sliding contact with the upstream sliding seal portion 32. More specifically, similar to the downstream sliding seal portion 33 shown in FIG. 4, the upstream sliding seal portion 32 has a pair of left and right bearings. The connecting tube 21 is in sliding contact with the upstream sliding seal portion 32 via the bearings. The connecting tube 21 can rotate in the forward and reverse directions together with the outer tube 20 around the rotation axis A.

[0021] The inner cylinder 22 is disposed radially inside the outer cylinder 20. The inner cylinder 22, together with the outer cylinder 20 and the connecting cylinder 21, is rotatable in the forward and reverse directions around the rotation axis A. The inner cylinder 22 includes an inner cylinder main body 220, an upstream feed fin 221, a downstream feed fin 222, and a plurality of scraping fins 223.

[0022] The inner cylinder body 220 has a cylindrical shape centered on the rotation axis A. When the inner cylinder body 220 is at an inclination angle of 0°, it extends in the left-right direction. A heat treatment zone B is set inside the inner cylinder body 220 (radially inside a heat insulating material 51 and a heater 52 of a heat treatment section 5 described later). In the heat treatment zone B, a predetermined heat treatment is performed on the workpiece W.

[0023] The left end opening of the inner cylinder body 220 is a supply port 220a for the workpiece W. The right end opening of the inner cylinder body 220 is a discharge port 220b for the workpiece W. As shown in FIG. 4, an attachment portion 220c is disposed at the right end of the inner cylinder body 220. The attachment portion 220c includes a flange portion 220d and four guide portions 220e. The flange portion 220d protrudes radially outward from the right end of the inner cylinder body 220. The flange portion 220d is annular. The four guide portions 220e protrude leftward from the radial outer end of the flange portion 220d. The four guide portions 220e are disposed at intervals of 90° in the circumferential direction. The guide portions 220e are protruding. An attachment hole 220f is opened in the guide portion 220e. A threaded portion (not shown) is formed on the inner circumferential surface of the mounting hole 220f.

[0024] A concave space that opens toward the left side is defined between the left surface of the flange portion 220d, the outer peripheral surface of the inner cylinder body 220, and the inner peripheral surface of the guide portion 220e. The right end of the outer cylinder body 200 is accommodated in this space. The mounting hole 220f of the guide portion 220e and the mounting hole 200a of the outer cylinder body 200 are aligned in the radial direction. A bolt (fastening member) 23 is inserted through these mounting holes 220f, 200a. The bolt 23 is fixed (screwed) to the mounting hole 220f and inserted into the mounting hole 200a. In this way, the inner cylinder 22 can be attached and detached to the outer cylinder 20 by the bolt 23.

[0025] The upstream feed fin 221 is disposed on the inner circumferential surface of the inner cylinder body 220. The upstream feed fin 221 is disposed near the left end of the heat treatment zone B (left of the axial center C of the heat treatment zone B). The upstream feed fin 221 has a spiral shape. More specifically, the upstream feed fin 221 extends in a direction intersecting the axial direction (extension direction of the rotation axis A) and circumferential direction of the inner cylinder body 220. The upstream feed fin 221 extends over a range of 540° (1.5 rotations) around the rotation axis A.

[0026] The downstream feed fin 222 is disposed on the inner circumferential surface of the inner cylinder body 220. The downstream feed fin 222 is disposed near the right end of the heat treatment zone B (to the right of the axial center C of the heat treatment zone B). The downstream feed fin 222 has a spiral shape. More specifically, the downstream feed fin 222 extends in a direction intersecting the axial and circumferential directions of the inner cylinder body 220. The downstream feed fin 222 extends over a range of 540° (1.5 rotations) around the rotation axis A.

[0027] The upstream feed fin 221 and the downstream feed fin 222 have the same radial height, pitch, and spiral length. The spiral winding direction of the upstream feed fin 221 and the downstream feed fin 222 are opposite to each other. For example, when viewed from the left side, the upstream feed fin 221 is wound clockwise, while the downstream feed fin 222 is wound counterclockwise.

[0028] When the inner cylinder 22 rotates in the forward direction, the workpiece W is sent to the right by the upstream feed fin 221. Also, the workpiece W is sent to the left by the downstream feed fin 222. That is, the workpiece W is sent in a direction approaching the heat treatment zone B. When the inner cylinder 22 rotates in the reverse direction, the workpiece W is sent to the left by the upstream feed fin 221. Also, the workpiece W is sent to the right by the downstream feed fin 222. That is, the workpiece W is sent in a direction away from the heat treatment zone B.

[0029] A plurality of scraping fins 223 are disposed on the inner peripheral surface of the inner cylinder body 220. As shown in Fig. 3, the plurality of scraping fins 223 are disposed at predetermined angular intervals around the rotation axis A. The scraping fins 223 are disposed between the upstream feed fin 221 and the downstream feed fin 222. The scraping fins 223 are disposed in the heat treatment zone B. The scraping fins 223 extend in the axial direction of the inner cylinder body 220.

[0030] (Heat Treatment Section 5) The heat treatment section 5 is disposed on the upper frame 94. The heat treatment section 5 includes a housing 50, a heat insulating material 51, and a heater (heat source) 52. The rotating cylinder section 2 penetrates the heat treatment section 5 in the left-right direction. The left-right middle portion of the rotating cylinder section 2 is accommodated in the heat treatment section 5. The housing 50 has a cylindrical shape. The heat insulating material 51 is laminated on the inner surface of the housing 50. The heater 52 is embedded in the heat insulating material 51. The inner peripheral surface of the heater 52 faces the outer peripheral surface of the outer cylinder main body 200 in the radial direction.

[0031] (Discharge section 6) The discharge section 6 is disposed on the right side of the rotating cylinder section 2. The discharge section 6 includes a discharge hood 60, a discharge chute 61, and a discharge container 62. The discharge hood 60 covers the right end of the rotating cylinder section 2 (specifically, the discharge port 220b of the inner cylinder body 220) from the right side. A lid 600 is disposed on an opening 60a at the right end of the discharge hood 60. The lid 600 can be opened and closed with respect to the opening 60a of the discharge hood 60. The downstream end of the pipe L2 is connected to the discharge hood 60. The upstream end of the pipe L2 is connected to a gas supply source (not shown). The discharge chute 61 is connected to the lower side (downstream side) of the discharge hood 60. The discharge chute 61 extends in the vertical direction. The discharge chute 61 includes a valve (not shown) and a bellows portion 610. The bellows portion 610 is deformable according to the amount of movement of the discharge hood 60 when the upper frame 94 is tilted. The discharge container 62 is connected to the lower side of the discharge chute 61. The discharge container 62 stores the workpiece W after the heat treatment.

[0032] (Supply section 4) The supply unit 4 is disposed on the left side of the rotating cylinder 2. The supply unit 4 includes a supply hood 40, a supply chute 41, a supply container 42, and a supply feeder 43. The supply hood 40 covers the left end of the rotating cylinder 2 (more specifically, the left end of the connecting cylinder 21) from the left side. The upstream end of the pipe L1 is connected to the supply hood 40. The downstream end of the pipe L1 is connected to a vacuum pump (not shown).

[0033] As shown in FIG. 3, the supply feeder 43 is a two-shaft screw feeder. The supply feeder 43 includes a supply pipe 430, a pair of feeder bodies 431, and a plurality of bearings 432. The plurality of bearings 432 are disposed in the upper frame 94. The supply pipe 430 penetrates the supply hood 40. The right end of the supply pipe 430 is inserted into the supply port 220a of the inner cylinder body 220. The right end of the supply pipe 430 is disposed radially inside the upstream feed fin 221. The feeder body 431 is disposed radially inside the supply pipe 430. The left end of the feeder body 431 is rotatably supported by the plurality of bearings 432. The feeder body 431 is rotatable around its own axis by a driving force from a driving device (not shown).

[0034] The supply chute 41 is connected to the upper side of the left end of the supply pipe 430. The supply chute 41 extends in the vertical direction. The supply chute 41 is equipped with a valve (not shown). The supply container 42 is connected to the upper side of the supply chute 41. The workpiece W before heat treatment is stored in the supply container 42.

[0035] [Heat treatment method] Next, a heat treatment method using the rotary kiln of this embodiment will be described. The heat treatment method includes a supply step, a heat treatment step, a shifting step, and a discharge step. During the heat treatment step, a gas supply source supplies a predetermined gas (such as an atmospheric gas) to the furnace space (the internal space of the supply hood 40, the rotating cylinder section 2, and the discharge hood 60) via the pipe L2. Also, a vacuum pump reduces the pressure in the furnace space via the pipe L1.

[0036] (Supply process) In this process, the rotary kiln 1 executes the supply mode. Specifically, first, the inclination angle of the upper frame 94, i.e., the outer cylinder 20 and the inner cylinder 22, is set to 0°. That is, the outer cylinder 20 and the inner cylinder 22 are arranged horizontally. Next, the outer cylinder 20 and the inner cylinder 22 are rotated in the forward direction. In addition, the supply feeder 43 is driven. In addition, the heater 52 of the heat treatment section 5 is energized to heat the heat treatment zone B inside the inner cylinder body 220 to a predetermined temperature from the radial outside of the outer cylinder body 200. Next, the workpiece W is supplied from the supply container 42 to the inside of the inner cylinder body 220, i.e., the heat treatment zone B, via the supply chute 41, the supply feeder 43, and the supply port 220a. After that, the supply feeder 43 is stopped.

[0037] (Heat treatment process) In this process, the rotary kiln 1 executes a heat treatment mode in a predetermined atmosphere as shown in Fig. 2. Specifically, while rotating the inner cylinder 22 in the forward direction and while maintaining the inclination angle of the inner cylinder 22 at 0°, the workpiece W in the heat treatment zone B is subjected to heat treatment in a predetermined temperature pattern (including the case where the temperature is constant) for a predetermined time. During the heat treatment, the workpiece W oscillates with the rotation of the inner cylinder 22. The workpiece W is also lifted up by the multiple lifting fins 223 and flows down by its own weight.

[0038] Here, the inner cylinder 22 is rotating in the forward direction. Therefore, the workpiece W near the upstream feed fin 221 is sent downstream (towards heat treatment zone B) by the upstream feed fin 221. Similarly, the workpiece W near the downstream feed fin 222 is sent upstream (towards heat treatment zone B) by the downstream feed fin 222. Therefore, the workpiece W remains in the heat treatment zone B.

[0039] (Pushing process) In this process, the rotary kiln 1 operates in the side-loading mode. Fig. 5 shows a partial axial cross-sectional view of the rotary kiln of this embodiment in the side-loading mode. Fig. 5 corresponds to Fig. 2.

[0040] In this step, while rotating the inner cylinder 22 in the forward direction, the elevation adjustment unit 96 is driven to tilt the upper frame 94 (i.e., the outer cylinder 20 and the inner cylinder 22) downward from left to right relative to the lower frame 93. The tilt angle θ of the outer cylinder 20 and the inner cylinder 22 in the shifting step is larger than the tilt angle θ (=0°) of the outer cylinder 20 and the inner cylinder 22 in the heat treatment step. Due to the tilting of the inner cylinder 22, the workpiece W is shifted toward the downstream side in the heat treatment zone B. That is, the workpiece W flows down inside the inner cylinder main body 220 so as to move away from the upstream feed fins 221 and approach the downstream feed fins 222.

[0041] (discharge process) In this process, the rotary kiln 1 performs the discharge mode. Fig. 6 shows a partial axial cross-sectional view of the rotary kiln of this embodiment in the discharge mode. Note that Fig. 6 corresponds to Fig. 2.

[0042] In this step, the rotation direction of the outer cylinder 20 and the inner cylinder 22 is reversed. That is, the outer cylinder 20 and the inner cylinder 22 are rotated in the opposite direction. Therefore, the workpiece W is sent downstream from the heat treatment zone B by the downstream feed fins 222. The workpiece W is stored in the discharge container 62 via the discharge port 220b and the discharge chute 61.

[0043] [How to attach and remove the inner cylinder] Next, a method for attaching and detaching the inner tube of the rotary kiln of this embodiment will be described. Fig. 7 shows a partial axial cross-sectional view of the rotary kiln of this embodiment before the inner tube is attached. The dashed line frame in Fig. 7 corresponds to frame II in Fig. 2.

[0044] The lid 600 shown in Fig. 1 can be opened and closed from the right side with respect to the opening 60a of the exhaust hood 60. When the inner tube 22 is to be removed from the outer tube 20, the lid 600 is first opened. As shown in Fig. 7, when the lid 600 is opened, the right end of the rotating tube portion 2 becomes accessible from the opening 60a. Next, the bolt 23 shown in Fig. 4 is pulled out radially outward from the mounting holes 220f, 200a through the opening 60a. Next, the inner tube 22 is pulled out to the right side from the outer tube 20 through the opening 60a.

[0045] When attaching the inner tube 22 to the outer tube 20, first, insert the inner tube 22 into the outer tube 20 from the right side through the opening 60a. Next, insert the bolt 23 shown in Fig. 4 into the mounting holes 220f, 200a from the radially outer side through the opening 60a. Then, close the lid 600 shown in Fig. 1.

[0046] In this manner, the inner cylinder 22 is attached to and detached from the outer cylinder 20. If a plurality of types of inner cylinders 22 are prepared, the plurality of types of inner cylinders 22 can be used interchangeably with a common outer cylinder 20.

[0047] [Effects] Next, the effects of the rotary kiln of this embodiment will be described. As shown in Fig. 2, the inner cylinder 22 of the rotary kiln 1 of this embodiment is provided with an upstream feed fin 221 and a downstream feed fin 222. In the heat treatment step (heat treatment mode), the workpiece W is fed in a direction approaching the heat treatment zone B (more specifically, the axial center C) by the upstream feed fin 221 and the downstream feed fin 222. In addition, the transport of the workpiece W in a direction away from the heat treatment zone B (more specifically, the axial center C) is suppressed. Therefore, the workpiece W can be subjected to batch processing.

[0048] 1, the upper frame 94 is tiltable relative to the lower frame 93. The outer cylinder 20 and the inner cylinder 22 are disposed on the upper frame 94. Therefore, the inner cylinder 22 is tiltable. Therefore, a desired inclination angle θ can be set for the inner cylinder 22.

[0049] 2 and 6, the inclination angle θ of the inner cylinder 22 in the heat treatment step is smaller than the inclination angle θ of the inner cylinder 22 in the discharge step (discharge mode). Therefore, in the heat treatment step, the workpiece W can be prevented from being unevenly distributed on the downstream side in the heat treatment zone B. This makes it easier to apply a uniform heat treatment to the workpiece W. Also, in the discharge step, the workpiece W can be quickly discharged from the heat treatment zone B by utilizing the weight of the workpiece W.

[0050] 2 and 5, the inclination angle θ of the inner cylinder 22 in the heat treatment step is smaller than the inclination angle θ of the inner cylinder 22 in the shifting step (shifting mode). Therefore, in the heat treatment step, the workpiece W can be prevented from being unevenly distributed on the downstream side in the heat treatment zone B. This makes it easy to perform a uniform heat treatment on the workpiece W. Also, in the shifting step, the weight of the workpiece W can be used to quickly bring the workpiece W close to the downstream feed fin 222. Also, in the shifting step, the weight of the workpiece W can be used to quickly move the workpiece W away from the upstream feed fin 221.

[0051] As shown in FIG. 2, the inclination angle θ of the inner cylinder 22 in the supply step (supply mode) is 0°. That is, the inner cylinder 22 is arranged horizontally. Therefore, in the supply step (supply mode), the workpiece W discharged from the supply feeder 43 is unlikely to be carried into the heat treatment zone B. In this regard, in the supply step, the inner cylinder 22 rotates in the forward direction. Therefore, even though the inner cylinder 22 is arranged horizontally, the workpiece W can be sent downstream by the upstream feed fins 221. Therefore, the workpiece W can be quickly carried into the heat treatment zone B.

[0052] 5, in the shifting step, the inner cylinder 22 is set to an inclination angle θ such that it descends from the left side to the right side. Therefore, the workpiece W flows down inside the inner cylinder body 220 by its own weight so as to move away from the upstream feed fin 221 and approach the downstream feed fin 222. Here, the inner cylinder 22 is rotating in the forward direction. Therefore, despite the setting of the inclination angle θ, the downstream feed fin 222 can suppress the outflow of the workpiece W from the heat treatment zone B.

[0053] As shown in Fig. 6, in the discharging process, the inner cylinder 22 rotates in the reverse direction. Let us assume that the workpiece W remains near the upstream feed fin 221. In this case, the workpiece W is sent from the heat treatment zone B to the upstream side, i.e., the supply port 220a side, by the upstream feed fin 221. In other words, the workpiece W flows back. However, due to the shifting process, the workpiece W near the upstream feed fin 221 has already flowed downstream. For this reason, the workpiece W is unlikely to remain near the upstream feed fin 221. Therefore, the backflow of the workpiece W in the discharging process can be suppressed.

[0054] 2, the upstream feed fin 221 is disposed near the left end of the heat treatment zone B. The left end of the upstream feed fin 221 protrudes to the left from the heat treatment zone B. On the other hand, the right end of the upstream feed fin 221 enters the heat treatment zone B. In other words, the upstream feed fin 221 is disposed on either side of the left end of the heat treatment zone B. Therefore, in the supply step, the workpiece W can be reliably fed into the heat treatment zone B. Also, in the heat treatment step, the workpiece W can be reliably retained in the heat treatment zone B.

[0055] 2, the downstream feed fin 222 is disposed near the right end of the heat treatment zone B. The right end of the downstream feed fin 222 protrudes to the right from the heat treatment zone B. On the other hand, the left end of the downstream feed fin 222 enters the heat treatment zone B. In other words, the downstream feed fin 222 is disposed on either side of the right end of the heat treatment zone B. Therefore, the workpiece W can be reliably retained in the heat treatment zone B during the heat treatment process and the shifting process. Furthermore, the workpiece W can be reliably sent out of the heat treatment zone B during the discharging process.

[0056] 2, the right end (discharge port) of the supply feeder 43 is disposed to the right of the left end of the upstream feed fin 221. Therefore, in the supply step, the workpiece W can be reliably sent to the heat treatment zone B.

[0057] 2 and 3, scraping fins 223 are arranged on the inner peripheral surface of the inner cylinder body 220. Therefore, the workpiece W can be stirred by utilizing the rotation of the inner cylinder body 220. Therefore, it is easy to perform a uniform heat treatment on the workpiece W.

[0058] 2 and 3, the scraping fins 223 extend in the axial direction of the inner cylinder body 220. That is, the extension direction of the scraping fins 223 does not include a circumferential component. Therefore, even if the workpiece W is scraped up by the scraping fins 223, it is difficult for it to move in the axial direction. Therefore, the workpiece W is unlikely to be unevenly distributed in the heat treatment zone B. Therefore, it is easy to apply a uniform heat treatment to the workpiece W.

[0059] As shown in Fig. 4, the inner cylinder 22 is attached to the outer cylinder 20 by bolts 23. Therefore, as shown in Fig. 7, the inner cylinder 22 can be easily attached and detached. Also, the outer cylinder 20 and the inner cylinder 22 can be easily aligned in the circumferential direction.

[0060] As shown in Fig. 4, a concave space that opens toward the left side is defined between the left surface of the flange portion 220d, the outer circumferential surface of the inner cylinder body 220, and the inner circumferential surface of the guide portion 220e. The right end of the outer cylinder body 200 is accommodated in this space. Therefore, the outer cylinder 20 and the inner cylinder 22 can be easily aligned in the axial direction.

[0061] As shown in Fig. 7, the inner cylinder 22 is replaceable with respect to the outer cylinder 20. By preparing a plurality of types of inner cylinders 22 according to the type of workpiece W, the plurality of types of inner cylinders 22 can be replaced and used with a common outer cylinder 20. In other words, the rotary kiln 1 can be shared for a plurality of types of workpieces W. For this reason, the rotary kiln 1 of this embodiment is suitable for use with small quantities of a wide variety of workpieces W.

[0062] As shown in FIG. 7, the rotary kiln 1 of this embodiment can be operated with the inner cylinder 22 removed from the outer cylinder 20. In this case, the heat treatment zone B is set inside the outer cylinder 20. The inclination angle θ of the outer cylinder 20 is constant in the carrying-in process, the heat treatment process, and the carrying-out process. The shifting process is not performed. In this way, the workpieces W can be subjected to continuous treatment (continuous heat treatment). In this way, the rotary kiln 1 of this embodiment can be switched between batch treatment and continuous treatment. Therefore, the rotary kiln 1 can be used in common for multiple types of workpieces W.

[0063] 1 can be opened and closed from the right side of the opening 60a of the exhaust hood 60. Therefore, when performing the work of attaching, detaching, or replacing the inner tube 22, the worker can easily approach the right end of the rotating tube portion 2 (the insertion end and removal end of the inner tube 22).

[0064] 2, the inclination angle θ of the inner cylinder 22 in the heat treatment step is set to 0°. Therefore, the heat treatment can be performed on the workpiece W in a horizontal state. Therefore, it is easy to perform a uniform heat treatment on the workpiece W.

[0065] 5 and 6, the inclination angle θ of the inner cylinder 22 is constant in the shifting step and the discharging step. Therefore, the upper frame 94 needs to be tilted only once relative to the lower frame 93. Also, the time required for the heat treatment method (from the supply step to the discharging step) can be shortened compared to the case where the inclination angle θ is switched between the shifting step and the discharging step.

[0066] [others] The rotary kiln of the present invention has been described above. However, the embodiment is not limited to the above embodiment. The present invention can be embodied in various modified and improved forms that can be achieved by those skilled in the art.

[0067] 8(A) to 8(E) show developments of the inner peripheral surface of the inner cylinder body of a rotary kiln according to other embodiments (Nos. 1 to 5). The same reference numerals are used to denote parts corresponding to those in FIG. 3. As shown in FIG. 3, the central angle φ is the central angle with respect to the rotation axis A when the inner cylinder body 220 is viewed from the right side. The central angle φ advances in the clockwise direction (upper → rear → lower → front) with the position directly above the rotation axis A being 0°.

[0068] As shown in Fig. 8(A), the inner cylinder body 220 may include only the upstream side feed fin 221 and the downstream side feed fin 222. The inner cylinder body 220 may not include the scraping fin 223 (see Fig. 3).

[0069] 8(B), the pitch of the upstream feed fin 221 may be greater than the pitch of the downstream feed fin 222. Conversely, the pitch of the downstream feed fin 222 may be greater than the pitch of the upstream feed fin 221. In this manner, the pitches of the upstream feed fin 221 and the downstream feed fin 222 may be the same or different.

[0070] Furthermore, the spiral length of the upstream feed fin 221 (360° of the central angle φ) may be shorter than the spiral length of the downstream feed fin 222 (720° of the central angle φ). Conversely, the spiral length of the downstream feed fin 222 may be shorter than the spiral length of the upstream feed fin 221. In this manner, the spiral lengths of the upstream feed fin 221 and the downstream feed fin 222 may be the same or different.

[0071] 8(C), the inner cylinder body 220 may include two upstream feed fins 221 and two downstream feed fins 222. In this manner, the number of the upstream feed fins 221 and the downstream feed fins 222 is not particularly limited. The number of the upstream feed fins 221 and the downstream feed fins 222 may be the same or different.

[0072] 8(D), the spiral length of the upstream feed fin 221 and the downstream feed fin 222 may be 90° (90° of the central angle φ). In other words, the spiral length may be 360° or less. The spiral length of the upstream feed fin 221 and the downstream feed fin 222 is not particularly limited.

[0073] As shown in Fig. 8(E), the upstream feed fin 221 may be an endless annular shape. It may also be an annular shape with ends, an arc shape, or the like. There is no particular limit to the number of upstream feed fins 221 to be arranged. Also, the upstream feed fin 221 may not be arranged.

[0074] The positional relationship between the upstream feed fin 221, the downstream feed fin 222, and the heat treatment zone B is not particularly limited. The left end of the upstream feed fin 221 may or may not protrude to the left from the heat treatment zone B. The right end of the upstream feed fin 221 may or may not enter the heat treatment zone B. In other words, it is sufficient that the upstream feed fin 221 is disposed to the left of the axial center C of the heat treatment zone B.

[0075] Similarly, the right end of the downstream feed fin 222 may or may not protrude to the right from the heat treatment zone B. The left end of the downstream feed fin 222 may or may not enter the heat treatment zone B. In other words, it is sufficient that the downstream feed fin 222 is disposed to the right of the axial center C of the heat treatment zone B.

[0076] 9(A) to 9(D) are radial cross-sectional views of the inner cylinder body of the rotary kiln according to other embodiments (Nos. 6 to 9). The same reference numerals are used to denote parts corresponding to those in FIG.

[0077] As shown in FIG. 9(A), the inner cylinder body 220 may include four scraper fins 223 spaced apart from each other by 90°. In this manner, the number and intervals of the scraper fins 223 are not particularly limited. As shown in FIG. 9(A), the radial height of the upstream feed fin 221 may be greater than the radial height of the scraper fin 223. As shown in FIG. 9(B), the radial height of the upstream feed fin 221 may be smaller than the radial height of the scraper fin 223. In this manner, the radial heights of the scraper fin 223 and the upstream feed fin 221 are not particularly limited. The same applies to the downstream feed fin 222.

[0078] 9(C), the cross-sectional shape of the scraping fin 223 (cross-sectional shape in the radial direction of the inner cylinder body 220) may be triangular. In this manner, the cross-sectional shape of the scraping fin 223 is not particularly limited. It may be rectangular, semicircular, or the like.

[0079] 9(D), the inner cylinder body 220 may not include the scraping fin 223, the upstream feed fin 221, and the downstream feed fin 222. In other words, the inner peripheral surface of the inner cylinder body 220 may be a smooth surface without any irregularities.

[0080] The inner cylinder 22 shown in Figures 8(A) to 8(E) and 9(A) to 9(D) may be arranged so as to be replaceable with respect to the outer cylinder 20 shown in Figure 7. That is, the inner cylinders 22 shown in Figures 7, 8(A) to 8(E) and 9(A) to 9(D) may be arranged so as to be replaceable with respect to the single rotary kiln 1 shown in Figure 1.

[0081] The material of the outer cylinder 20 and the inner cylinder 22 is not particularly limited. It may be metal, ceramics, carbon, glass, etc. The outer cylinder 20 may be a unitary body or composed of multiple members. When composed of multiple members, the materials of each member may be the same or different. The same applies to the inner cylinder 22. The radial cross-sectional shape of the outer cylinder main body 200 and the inner cylinder main body 220 is not particularly limited. It may be cylindrical, polygonal (rectangle, hexagon, octagon, etc.), cylindrical, etc.

[0082] The type of the rotary kiln 1 is not particularly limited. It may be an externally heated rotary kiln in which the heat treatment zone B inside the inner cylindrical body 220 is indirectly heated from the outside of the inner cylindrical body 220 through the cylindrical wall of the inner cylindrical body 220. It may be an internally heated rotary kiln in which the heat treatment zone B inside the inner cylindrical body 220 is directly heated from the inside of the inner cylindrical body 220.

[0083] The position of the right end (discharge port) of the supply feeder 43 is not particularly limited. For example, the right end of the supply feeder 43 may be disposed inside the heat treatment zone B. Also, the right end of the supply feeder 43 may be disposed outside the heat treatment zone B. The type of the supply feeder 43 is not particularly limited. For example, it may be a screw feeder, an air current conveying feeder, or the like. The type of the lift adjustment unit 96 is not particularly limited. For example, it may be an electric jack, a hydraulic cylinder, or the like.

[0084] A gas supply source may be connected to the pipe L1, and a vacuum pump may be connected to the pipe L2. Alternatively, the vacuum pump may be driven to reduce the pressure in the furnace without driving the gas supply source. Alternatively, the gas supply source and the vacuum pump may be switchably connected to the pipe L1. Similarly, the gas supply source and the vacuum pump may be switchably connected to the pipe L2.

[0085] The atmosphere of the heat treatment zone B is not particularly limited. The gas supplied from the gas supply source to the furnace space through the pipe L2 may be air, ammonia, an inert gas (helium, argon, nitrogen, carbon dioxide, etc.), a reducing gas (hydrogen, carbon monoxide, hydrocarbon, etc.), an oxidizing gas (oxygen, water vapor, combustion gas, etc.), etc. The atmosphere of the heat treatment zone B may be air or a vacuum (an atmosphere with a pressure lower than atmospheric pressure).

[0086] The type of the workpiece W (material, characteristics, shape, size, etc.) is not particularly limited. The material may be an organic substance, an inorganic substance, a metal, etc. The shape may be a powder, a granular substance, a lump, etc. Specifically, the workpiece W may be a medicine, a battery material (positive electrode material, negative electrode material, electrolyte), a food, a waste material, etc. The rotary kiln of the present invention can easily perform a uniform heat treatment on the workpiece W in the heat treatment process, and therefore can easily homogenize the quality of the workpiece W. For this reason, it is particularly suitable for medicines, battery materials, etc.

[0087] The inclination angle θ of the inner cylinder 22 in the shifting step and the discharge step of the heat treatment method is not particularly limited. For example, it may be any angle within the range of 1° to 5°. Of course, the inclination angle θ may be less than 1° or more than 5°. In addition, the inclination angle θ may be switched between the shifting step and the discharge step. The inclination angle θ of the inner cylinder 22 in each step (supply step, heat treatment step, shifting step, discharge step) is not particularly limited. It may be positive (a direction descending from the upstream side to the downstream side), negative (a direction ascending from the upstream side to the downstream side), or 0. Alternatively, each step may be performed while changing the inclination angle θ. For example, in the shifting step, the inclination angle θ may be gradually increased from the beginning to the end.

[0088] The time required for each step of the heat treatment method is not particularly limited. At least a part of two chronologically consecutive steps may overlap. For example, the end of the supply step and the start of the heat treatment step may overlap. The end of the heat treatment step and the start of the shifting step may overlap.

[0089] Each step of the heat treatment method may be performed automatically. In this case, the rotary kiln 1 shown in FIG. 1 is equipped with a control device (computer, PLC (programmable logic controller), etc.). The control device controls the inclination angle θ and rotation of the outer cylinder 20 and the inner cylinder 22, the rotation of the supply feeder 43, the temperature of the heat treatment zone B, the valve of the supply section 4, the valve of the discharge section 6, etc., via the lift adjustment section 96, the drive device, the heater 52, etc. The control device automatically performs each step of the heat treatment method based on a processing program for the workpiece stored in the memory section (a program related to the required time for each step, etc.). [Explanation of symbols]

[0090] 1: rotary kiln, 2: rotating cylinder, 20: outer cylinder, 200: outer cylinder body, 200a: mounting hole, 201: upstream tire, 202: downstream tire, 203: sprocket, 21: connecting cylinder, 22: inner cylinder, 220: inner cylinder body, 220a: supply port, 220b: discharge port, 220c: mounting portion, 220d: flange portion, 220e: guide portion, 220f: mounting hole, 221: upstream feed fin, 222: downstream feed fin, 223: scraping fin, 23: bolt, 3: rotation support portion, 30: upstream roller, 31: downstream roller, 32: upstream side sliding seal part, 33: downstream side sliding seal part, 330: bearing, 4: supply part, 40: supply hood, 41: supply chute, 42: supply container, 43: supply feeder, 430: supply pipe, 431: feeder body, 432: bearing part, 5: heat treatment part, 50: housing, 51: heat insulating material, 52: heater, 6: discharge part, 60: discharge hood, 60a: opening, 600: lid, 61: discharge chute, 610: bellows part, 62: discharge container, 9: stand, 93: lower frame (base part), 94: upper frame (tilting part), 95: tilting axis, 96: elevation adjustment part θ: inclination angle, φ: central angle, A: rotation axis, B: heat treatment zone, C: axial center, W: workpiece

Claims

1. an outer cylinder capable of rotating in both forward and reverse directions about its own axis; an inner cylinder disposed radially inside the outer cylinder and rotatable together with the outer cylinder, the inner cylinder having a heat treatment zone therein for subjecting a workpiece to a heat treatment; A rotary kiln comprising: The inner cylinder has a cylindrical inner cylinder body and a spiral downstream feed fin arranged on an inner circumferential surface of the inner cylinder body downstream of an axial center of the heat treatment zone, When the inner cylinder rotates in the forward direction, the workpiece is fed by the downstream feed fin in a direction approaching the heat treatment zone, When the inner cylinder rotates in the reverse direction, the workpiece is fed by the downstream feed fin in a direction away from the heat treatment zone, In a heat treatment mode in which the workpiece is subjected to a heat treatment, the inner cylinder is rotated in the forward direction, the workpiece is retained in the heat treatment zone, and the workpiece is subjected to a heat treatment; In a biasing mode in which the workpiece is biased toward the downstream side, the inner cylinder is rotated in the forward direction, and the inner cylinder is tilted so that the downward inclination from the upstream side to the downstream side becomes larger than in the heat treatment mode, thereby biasing the workpiece toward the downstream side in the heat treatment zone, In a discharge mode for discharging the material to be treated, the inner cylinder is rotated in a reverse direction to move the material to a downstream side from the heat treatment zone.

2. The inner cylinder further includes a spiral upstream feed fin disposed on an inner circumferential surface of the inner cylinder body upstream of an axial center of the heat treatment zone, The spiral winding direction of the upstream feed fin and the spiral winding direction of the downstream feed fin are opposite to each other, When the inner cylinder rotates in the forward direction, the workpiece is fed by the upstream feed fin and the downstream feed fin in a direction approaching the heat treatment zone, The rotary kiln according to claim 1 , wherein when the inner cylinder rotates in the reverse direction, the workpiece is fed in a direction away from the heat treatment zone by the upstream feed fin and the downstream feed fin.

3. Further, the present invention includes a base portion and a tilt portion that is tiltable relative to the base portion, The rotary kiln according to claim 1 or 2, wherein the outer cylinder and the inner cylinder are disposed on the tilting portion.

4. In the heat treatment mode, the inclination of the inner cylinder is 0°; 4. The rotary kiln according to claim 1, wherein the inclination of the inner cylinder is constant in the one-side shifting mode and the discharge mode.

5. A rotary kiln as described in any one of claims 1 to 4, wherein the inner tube further has a scraping fin arranged in the heat treatment zone on the inner surface of the inner tube body and scraping up the workpiece in response to the rotation of the inner tube.

6. 6. The rotary kiln according to claim 1, wherein the inner cylinder is detachable and replaceable from the outer cylinder.

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