rotary kiln

Abstract

To provide a rotary kiln which exhausts a material after heat treatment in a state where its temperature is lowered.SOLUTION: A rotary kiln 10 comprises: a material feed part 13 provided at a side of a first end 12a of a heating pipe 12; a material recovery part 14 provided at a side of a second end 12b; an inner cylinder 15 supported in a state of being inserted into a central part of the heating pipe 12, at the side of the second end 12b; branch pipes plurally provided in a circumferential direction on an outer circumferential face of the inner cylinder 15, respectively branched from the inner cylinder 15, and extending in an axial direction along an inner circumferential face of the heating pipe 12; a hot air feed pipe 17 relatively rotatably supported relative to the inner cylinder 15 in a state of being inserted into one end of the inner cylinder 15 extending outside the heating pipe 12; and a driving mechanism 18 rotating the heating pipe 12. The inner cylinder 15 is supported relative to the heating pipe 12 via a spring 101.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to rotary kilns. [Background technology]

[0002] Japanese Patent Application Laid-Open Publication No. 2000-246210 discloses a pyrolysis drum that includes a horizontal rotating drum that receives waste from a screw conveyor into its hollow space, multiple heat transfer tubes that circulate heated gas as a heat medium for heating the waste and are arranged in the hollow space of the rotating drum along the longitudinal direction of the rotating drum, and a heated gas supply section, heated gas discharge section, and pyrolysis gas / pyrolysis residue discharge section for the heat transfer tubes.

[0003] Japanese Patent Application Laid-Open Publication No. 2006-57974 discloses a waste pyrolysis facility that includes a pyrolysis drum having a heating gas inlet housing at one end of a drum body with a heating pipe installed and a heating gas outlet housing at the other end of the drum body, and a pyrolysis gas combustion furnace that supplies combustion exhaust gas, produced by burning part of the pyrolysis gas, as heating gas to the heating gas inlet housing.

[0004] Japanese Patent Publication No. 7125532 discloses a rotary kiln having an inner cylinder placed inside a substantially cylindrical heating tube, multiple branch pipes branching off from the inner cylinder, and a hot air supply pipe that supplies hot air to the branch pipes through the inner cylinder. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-246210 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-57974 [Patent Document 3] Patent No. 7125532 Summary of the Invention [Problem to be solved by the invention]

[0006] However, each component of the rotary kiln thermally expands during heat treatment, and it is desirable to minimize distortion caused by the thermal expansion of the rotary kiln. [Means for solving the problem]

[0007] The rotary kiln disclosed herein includes a heating tube, a material supply unit, a material recovery unit, an inner cylinder, branch pipes, and a drive mechanism. The heating tube is a substantially cylindrical tube. The material supply unit is provided on a first end side of the heating tube. The material recovery unit is provided on a second end side of the heating tube. The inner cylinder is supported at the second end side of the heating tube while being inserted into the center of the heating tube. A plurality of branch pipes are provided circumferentially on the outer peripheral surface of the inner cylinder within the heating tube, each branching from the inner cylinder and extending axially along the inner peripheral surface of the heating tube. The hot air supply pipe is inserted into one end of the inner cylinder extending outside the heating tube and supported so as to be rotatable relative to the inner cylinder. The drive mechanism rotates the heating tube. Here, the inner cylinder is connected to the heating tube via a spring. According to this rotary kiln, even if a dimensional difference occurs between the inner cylinder and the heating tube due to thermal expansion, the portion where the inner cylinder is attached to the heating tube is allowed to shift relative to one another. Therefore, distortion caused by thermal expansion can be kept small. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a vertical cross-sectional front view of a rotary kiln 10. [Figure 2] FIG. 2 is a side view taken along the line II-II of FIG. [Figure 3] 3 is a side view taken along the line III-III in FIG. 1. FIG. [Figure 4] FIG. 4 is a cross-sectional view of the heating tube 12 shown in FIG. 1 taken along line IV-IV. [Figure 5] FIG. 5 is a VV cross-sectional view of the heating tube 12 shown in FIG. [Figure 6] FIG. 6 is a cross-sectional view of the heating tube 12 taken along the line VI-VI in FIG. [Figure 7]FIG. 7 is a cross-sectional view of the heating tube 12 shown in FIG. 1 taken along line VII-VII. [Figure 8] FIG. 8 is a cross-sectional view of the heating tube 12 shown in FIG. 1 taken along line VIII-VIII. [Figure 9] FIG. 9 is a cross-sectional view of the heating tube 12. [Figure 10] FIG. 10 is a vertical cross-sectional front view of the rotary kiln 10A. [Figure 11] FIG. 11 is a vertical cross-sectional front view of the rotary kiln 10B. [Figure 12] FIG. 12 is a cross-sectional view taken along line XII-XII in FIG. [Figure 13] FIG. 13 is a vertical cross-sectional front view of the rotary kiln 10C. [Figure 14] FIG. 14 is a vertical cross-sectional front view of the rotary kiln 10C. [Figure 15] FIG. 15 is a view taken along the line XV-XV in FIG. [Figure 16] FIG. 16 is a vertical sectional front view showing the connection structure between the inner cylinder 15 and the hot air supply pipe 17. As shown in FIG. [Figure 17] FIG. 17 is a view taken along the line XVII-XVII in FIG. [Figure 18] FIG. 18 is a side view showing the mounting structure of the exhaust pipe 82. [Figure 19] FIG. 19 is a side view showing another embodiment of the support structure for the branch pipe 16. In FIG. DETAILED DESCRIPTION OF THE INVENTION

[0009] A typical embodiment of the present disclosure will be described in detail below with reference to the drawings. In the following drawings, components and parts that perform the same function are denoted by the same reference numerals. Furthermore, the dimensional relationships (length, width, thickness, etc.) in each drawing do not reflect the actual dimensional relationships.

[0010] Rotary Kiln 10 Fig. 1 is a longitudinal sectional front view of a rotary kiln 10. As shown in Fig. 1, the rotary kiln 10 includes a heating pipe 12, a material supply section 13, a material recovery section 14, an inner cylinder 15, branch pipes 16, a hot air supply pipe 17, a drive mechanism 18, and an exhaust duct 20.

[0011] <Heating tube 12> In the embodiment shown in FIG. 1, the heating tube 12 of the rotary kiln 10 is a substantially cylindrical tube, and although the axis is depicted as being horizontal, in reality it is sloped at a predetermined angle. The first end 12a of the heating tube 12 is positioned higher than the second end 12b. The heating tube 12 may have a required length as a heating furnace for heating materials. Here, the heating tube 12 is a cylindrical tube, but it may be provided with a flange or the like, and may not be a perfect cylinder in detail.

[0012] The material to be supplied here is, for example, ceramic powder, such as barium titanate powder, or metal powder, such as ferrite powder, and is used to sinter these powder-like materials. From this perspective, the heating tube 12 is required to have a required corrosion resistance depending on the material to be heated and the atmospheric gas used during heating. In this embodiment, stainless steel (e.g., SUS316) can be used for the heating tube 12. Depending on the application, the heating tube 12 may be made of ceramic.

[0013] The heating tube 12 is appropriately referred to as a "furnace tube" or the like. In this embodiment, flanges 12a1 and 12b1 are provided at the end of the first end 12a side and the end of the second end 12b side of the heating tube 12, respectively. In this embodiment, the first end 12a side of the heating tube 12 is disposed higher than the second end 12b side, and thus the material is transported downward at a predetermined speed in accordance with the rotation of the heating tube 12. From this viewpoint, the heating tube 12 may be installed with a gradient of, for example, about 0.5 degrees to 1 degree. With a gradient of about 0.5 degrees to 1 degree, the powdered material is less likely to slip off and the powdered material is easily transported at an appropriate speed in accordance with the rotation of the heating tube 12. Therefore, by adjusting the rotation speed of the heating tube 12, the residence time of the material in the heating tube 12 can be adjusted. The gradient angle is not limited to the above, and an appropriate angle, for example, an angle of about 0.3 degrees to 2 degrees, may be selected.

[0014] In the embodiment shown in FIG. 1 , the heating tube 12 is sloped so that the first end 12a is positioned higher than the second end 12b. The heating tube 12 is not limited to a sloped configuration unless otherwise specified. For example, spiral blades may be provided on the inner circumferential surface of the heating tube 12 so that the powdered material is sent from the first end 12a to the second end 12b as the heating tube 12 rotates. In this case, the heating tube 12 does not need to have a slope because the powdered material is sent from the first end 12a to the second end 12b as the heating tube 12 rotates. In this way, the heating tube 12 may be configured so that the powdered material is sent from the first end 12a to the second end 12b as the heating tube 12 rotates in the circumferential direction.

[0015] <Heating chamber 25> In the embodiment shown in FIG. 1, the rotary kiln 10 further includes a tunnel-shaped furnace body 27 and a heater 26. The furnace body 27 has a heating chamber 25 inside. In this embodiment, the heating chamber 25 may be surrounded by a furnace wall formed, for example, by stacking ceramic fiber boards formed into a predetermined shape. The ceramic fiber board is, for example, a plate material formed by adding an inorganic filler and an inorganic / organic binder to so-called bulk fiber. The furnace wall has a required thickness that sufficiently insulates the heating chamber 25 from heat. The heater 26 is a device that heats the workpiece in the heating chamber 25. As shown in FIG. 1, the heating tube 12 may be inserted into the heating chamber 25 and rotatably supported. In this embodiment, the heating chamber 25 is provided with partitions 28 that divide the heating chamber 25 into several spaces in the direction in which the heating tube 12 is inserted. The partitions 28 may be made of ceramic fiber boards, just like the furnace walls that form the heating chamber 25. In this way, the heating chamber 25 is divided into several spaces, so that the heating pipe 12 can be heated to a predetermined temperature from the outside, and the temperature of the heating pipe 12 is adjusted locally.

[0016] FIG. 2 is a side view taken along the line II-II in FIG. 1. FIG. 2 shows the end of the first end 12a of the heating pipe 12. As shown in FIG. 2, flanges 12a1 are provided intermittently at the end of the first end 12a of the heating pipe 12. In this embodiment, four flanges 12a1 are evenly spaced in the circumferential direction. A support plate 12a2 that supports the material supply unit 13 and the end of the branch pipe 16 is attached to the flange 12a1. In this embodiment, the support plate 12a2 is attached to the end of the first end 12a of the heating pipe 12 and closes the opening of the first end 12a of the heating pipe 12. Furthermore, at the first end 12a of the heating pipe 12, the end 16a of the branch pipe 16 penetrates the support plate 12a2 and is exposed to the outside from the first end 12a of the heating pipe 12. An exhaust duct 20 is provided at the first end 12a of the heating pipe 12 so as to cover the end 16a of the branch pipe 16.

[0017] <Material supply section 13> The material supply unit 13 is provided on the first end 12a side of the heating tube 12, and is a portion that supplies the material to be processed into the heating tube 12. In this embodiment, the material supply unit 13 is configured with a screw feeder 40. A discharge port 41 of the screw feeder 40 serving as the material supply unit 13 penetrates the support plate 12a2 and is inserted into the heating tube 12. In this embodiment, although not shown, the material is configured to be supplied from a supply hopper into the heating tube 12 at a predetermined speed by the screw feeder 40. An atmospheric gas used when heating the material may be supplied into the heating tube 12 through the screw feeder 40. Furthermore, the heating tube 12 may be provided with a separate gas supply pipe for supplying the atmospheric gas used when heating.

[0018] <Exhaust Duct 20> The exhaust duct 20 covers the first end 12a side of the heating pipe 12. A screw feeder 40 constituting the material supply unit 13 penetrates the exhaust duct 20 and the support plate 12a2 to reach the inside of the heating pipe 12. Here, a sealant 42 is attached to the portion where the screw feeder 40 penetrates the exhaust duct 20. The exhaust duct 20 is a member that covers the first end 12a side of the heating pipe 12.

[0019] An exhaust port 21 is provided above the exhaust duct 20. A drain 22 may be provided at the bottom of the exhaust duct 20. A thermal insulation pipe 46 is attached to the outer peripheral surface of the end of the heating pipe 12 on the first end 12a side. An opening 44 is formed in the exhaust duct 20. The end of the heating pipe 12 on the first end 12a side is inserted into the opening 44. In this embodiment, the thermal insulation pipe 46 is attached to the end of the heating pipe 12 on the first end 12a side, and a sealing member 48 is attached to the thermal insulation pipe 46. The sealing member 48 is a member that prevents the atmosphere inside the exhaust duct 20 from leaking to the outside, and closes the gap between the opening 44 of the exhaust duct 20 and the thermal insulation pipe 46 attached to the heating pipe 12.

[0020] Fig. 3 is a side view taken along the line III-III in Fig. 1. Fig. 3 shows the end portion of the heating tube 12 on the second end 12b side. As shown in Fig. 3, flanges 12b1 are provided intermittently at the end portion of the heating tube 12 on the second end 12b side. In this embodiment, four flanges 12b1 are arranged evenly in the circumferential direction. The inner cylinder 15 is supported by the flanges 12b1.

[0021] <Inner cylinder 15> The inner tube 15 is a pipe that is supported in a state where it is inserted into the center of the heating tube 12 on the second end 12b side of the heating tube 12 and rotates together with the heating tube 12. In this embodiment, the inner tube 15 is composed of a first inner tube 15a and a second inner tube 15b. The outer diameter of the first inner tube 15a is smaller than the inner diameter of the heating tube 12, and a flange 31 is provided at the end of the first inner tube 15a, to which a flange 32 of the second inner tube 15b is connected by a coupling. The second inner tube 15b has the same inner diameter as the first inner tube 15a and is a pipe into which the hot air supply tube 17 is inserted. The flange 31 of the first inner tube 15a is provided with a rib 33 extending in the outer diameter direction. A flange 12b1 on the second end 12b side of the first inner tube 15a is attached to the rib 33. As a result, the first inner tube 15a is supported in a state where it extends along the central axis of the heating tube 12 via the rib 33. 1 and 3, at the end portion on the second end 12b side of the heating tube 12, a gap on the outside of the first inner cylinder 15a is open, and serves as a discharge port 12b2 through which the material is discharged. In this embodiment, the inner cylinder 15 is cylindrical. Therefore, in the radial direction of the heating tube 12, a roughly constant gap is formed between the outer peripheral surface of the inner cylinder 15 and the inner peripheral surface of the heating tube 12.

[0022] <Material Recovery Section 14> The material recovery section 14 is provided on the second end 12b side of the heating tube 12. The material recovery section 14 is a portion where the material discharged from the discharge port 12b2 of the heating tube 12 is recovered. In this embodiment, the material recovery section 14 is provided on the outside of the end portion on the second end 12b side of the heating tube 12. The material recovery section 14 includes a casing 51, a hopper 52, and an inner cylinder cover 53.

[0023] <Casing 51> The casing 51 is a member having a substantially rectangular container shape that covers the outside of the end portion on the second end 12b side of the heating pipe 12. An opening 54 is formed on one side of the casing 51. The end portion on the second end 12b side of the heating pipe 12 is inserted into the opening 54. In this embodiment, a thermal insulation pipe 56 is attached to the end portion on the second end 12b side of the heating pipe 12, and a seal member 58 is attached to the thermal insulation pipe 56. The seal member 58 is a member that prevents the atmosphere inside the casing 51 from leaking to the outside, and closes the gap between the opening 54 of the casing 51 and the thermal insulation pipe 56 attached to the heating pipe 12.

[0024] An opening 55 is formed on the side of the casing 51 facing the opening 54. An inner cylinder cover 53 is attached to the opening 55. The inner cylinder cover 53 is a member that covers the periphery of the second inner cylinder 15b, which is connected to the first inner cylinder 15a protruding from the end of the heating pipe 12 on the second end 12b side. The second inner cylinder 15b is rotatably supported on the inner surface of the inner cylinder cover 53 via a sealed bearing 36. A hot air supply pipe 17 of the hot air generator 60 is attached to the inner cylinder cover 53. The hot air supply pipe 17 is inserted into one end of the inner cylinder 15 extending outside the heating pipe and supported so as to be rotatable relative to the inner cylinder 15. In this embodiment, the hot air supply pipe 17 is inserted into one end of the second inner cylinder 15b, which forms part of the inner cylinder 15.

[0025] <Hot air generator 60> Here, the hot air generator 60 may be, for example, a gas burner or an oil burner. Alternatively, the hot air generator 60 may be an external boiler. The hot air supply pipe 17 supplies hot air from the hot air generator 60 to the second inner cylinder 15b. The hot air supplied to the second inner cylinder 15b is then supplied to the first inner cylinder 15a. A sealed bearing 37 is attached between the inner circumferential surface of the second inner cylinder 15b and the outer circumferential surface of the hot air supply pipe 17. The second inner cylinder 15b is rotatably supported relative to the hot air supply pipe 17 by the sealed bearing 37. Therefore, the inner cylinder 15 rotates, but the hot air supply pipe 17 does not. A seal 38 is attached around the hot air supply pipe 17 at the end of the second inner cylinder 15b. The seal 38 prevents the hot air atmosphere supplied to the second inner cylinder 15b from leaking into the casing 51. Furthermore, a seal 39 is also attached to the end of the inner cylinder cover 53 around the hot air supply pipe 17. The seal 39 is configured to prevent the atmosphere inside the casing 51 from leaking to the outside through the inner cylinder cover 53.

[0026] Hopper 52 The hopper 52 is provided at the bottom of the casing 51. In this embodiment, the hopper 52 has a bottom surface with both sides sloping so that the gap between them narrows toward the bottom of the casing 51. The heat-treated material discharged into the casing 51 from the end of the heating pipe 12 on the second end 12b side is collected and recovered through the hopper 52 provided at the bottom of the casing 51. An openable and closable valve 52a is attached to the bottom of the hopper 52. In addition, a recovery container (not shown) is provided. The valve 52a of the hopper 52 is opened and closed as appropriate, and the treated material collected through the hopper 52 is transferred to the recovery container.

[0027] <Branch pipe 16> The branch pipes 16 are provided in a plurality of circumferential directions on the outer peripheral surface of the inner cylinder 15 within the heating pipe 12, and are composed of a plurality of pipes that branch off from the inner cylinder 15 and extend in the axial direction along the inner peripheral surface of the heating pipe 12.

[0028] Here, Fig. 4 is a IV-IV cross-sectional view of the heating pipe 12 shown in Fig. 1. Fig. 5 is a VV cross-sectional view of the heating pipe 12 shown in Fig. 1. Figs. 4 and 5 each show a base end of a branch pipe 16 branching off from the inner cylinder 15. In this embodiment, the inner cylinder 15 extends a predetermined length into the heating pipe 12 from the end on the second end 12b side of the heating pipe 12. Twelve branch pipes 16 branch off from the inner cylinder 15 inside the heating pipe 12. The twelve branch pipes 16 are evenly arranged circumferentially around the inner cylinder 15, and each extend in the axial direction along the inner circumferential surface of the heating pipe 12.

[0029] In this embodiment, as shown in FIG. 4 , six branch pipes 16 branch off from the inner cylinder 15 at a predetermined distance from the end of the heating pipe 12 on the second end 12b side. These six branch pipes 16 are evenly arranged around the inner cylinder 15 in the circumferential direction, and as shown in FIG. 1 , each extends axially along the inner circumferential surface of the heating pipe 12 toward the first end 12a side. As shown in FIG. 5 , the other six branch pipes 16 branch off from the inner cylinder 15 at a predetermined distance from the end of the heating pipe 12 on the second end 12b side. These six branch pipes 16 are arranged between the six branched branch pipes 16, and each extends axially along the inner circumferential surface of the heating pipe 12 toward the first end 12a side. Thus, in this embodiment, the twelve branch pipes 16 are evenly arranged around the inner cylinder 15 in the circumferential direction, and each extends axially along the inner circumferential surface of the heating pipe 12 toward the first end 12a side.

[0030] In this embodiment, the multiple branch pipes 16 branching off from the inner cylinder 15 are branched off at different positions in the longitudinal direction of the inner cylinder 15. In this case, the branching locations of the branch pipes 16 are dispersed, maintaining the strength of the inner cylinder 15 and facilitating the production of the inner cylinder 15 and the branch pipes 16. In this embodiment, the branch pipes 16 are cylindrical and have a circular cross section.

[0031] FIG. 6 is a VI-VI cross-sectional view of the heating pipe 12 shown in FIG. 1. FIG. 7 is a VII-VII cross-sectional view of the heating pipe 12 shown in FIG. 1. FIGS. 6 and 7 respectively show supports 61 and 62 that support intermediate portions of branch pipes 16 branching off from the inner cylinder 15. The support 61 is arranged on the second end side in the intermediate portion of the branch pipe 16. In this embodiment, the support 61 supports six of the twelve branch pipes 16 that are evenly arranged in the circumferential direction. The support 61 has arms 61a extending radially from the center, and the branch pipes 16 are held at the tips of the arms 61a. The support 62 supports the other six of the twelve branch pipes 16 that are evenly arranged in the circumferential direction. The support 62 has arms 62a extending radially from the center, and the branch pipes 16 are held at the tips of the arms 62a. In this embodiment, the supports 61 and 62 are offset from each other by 30 degrees in the circumferential direction of the heating pipe 12, and each support holds six branch pipes 16. Material flowing from the first end 12a side to the second end 12b side of the heating pipe 12 passes through the gaps between the arms 61a and 62a of the supports 61 and 62. A plurality of such supports 61 and 62 may be provided in the longitudinal direction of the branch pipe 16.

[0032] Here, the branch pipes 16 arranged on the heating pipe 12 have been described, but the configuration of the branch pipes 16 is not limited to this embodiment. In this embodiment, there are twelve branch pipes 16, but the number of branch pipes is not limited to twelve. Furthermore, in the above-described embodiment, the branch pipes 16 are arranged evenly in the circumferential direction, but they do not necessarily have to be arranged evenly. A support that supports the middle part of the branch pipe 16 does not necessarily have to be attached when the heating pipe 12 or the branch pipe 16 is short, for example.

[0033] <Drive mechanism 18> The drive mechanism 18 is a mechanism for rotating the heating pipe 12. A thermal insulation pipe 46 is attached to the end of the heating pipe 12 on the first end 12a side, and a thermal insulation pipe 56 is attached to the end of the heating pipe 12 on the second end 12b side. A chain sprocket 18a and a tire 18b are attached to the outside of the thermal insulation pipe 46 on the first end 12a side. A tire 18c is attached to the outside of the thermal insulation pipe 56 on the second end 12b side. The tires 18b and 18c are supported by rollers 18d and 18e, respectively. As a result, both ends of the heating pipe 12 are rotatably supported via the tires 18b and 18c.

[0034] FIG. 8 is a cross-sectional view taken along the line VIII-VIII of the heating pipe 12 shown in FIG. 1 . FIG. 8 illustrates a chain sprocket 18a attached to the outer periphery of the heating pipe 12. In this embodiment, as shown in FIG. 8 , the chain sprocket 18a is attached to the outside of a thermal insulation pipe 46 provided on the first end 12a side of the heating pipe 12. As shown in FIG. 8 , a chain 18f is wound around the chain sprocket 18a. The chain 18f receives driving force from a driving device (not shown) to rotate the chain sprocket 18a, thereby rotating the heating pipe 12. In this embodiment, the heating pipe 12, the inner tube 15, and the branch pipe 16 are connected to each other, and when the heating pipe 12 rotates, the heating pipe 12, the inner tube 15, and the branch pipe 16 rotate integrally. The chain sprocket 18a is a half-split member and is attached to the outside of the thermal insulation pipe 46 on the outer periphery of the heating pipe 12. Note that, in FIG. 8 , the interior of the heating pipe 12, such as the branch pipe 16, is omitted from illustration as appropriate.

[0035] In the rotary kiln 10 shown in FIG. 1, material is supplied to the heating tube 12 from a screw feeder 40 attached to the first end 12a of the heating tube 12. The material is fed from the screw feeder 40 into the heating tube 12 at a predetermined speed. FIG. 9 is a cross-sectional view of the heating tube 12. FIG. 9 shows material M1 supplied to the heating tube 12. As described above, the heating tube 12 is sloped so that the first end 12a is higher than the second end 12b. The heating tube 12 is rotated at a predetermined speed by a drive mechanism 18. The material supplied from the screw feeder 40 into the heating tube 12 is leveled by the rotation of the heating tube 12, as shown in FIG. 9, and gradually flows toward the second end 12b while accumulating at a predetermined depth in the lower part of the heating tube 12.

[0036] In this embodiment, the inner tube 15 is cylindrical, and a roughly constant gap is formed between the outer circumferential surface of the inner tube 15 and the inner circumferential surface of the heating tube 12 in the radial direction of the heating tube 12. The material M1 is preferably supplied, for example, to a depth such that it does not contact the outer circumferential surface of the inner tube 15. This prevents the material M1 from directly contacting the inner tube 15, and heat transfer from the inner tube 15 to the material M1 is suppressed. As described above, multiple branch pipes 16 extend axially inside the heating tube 12 along the inner circumferential surface of the heating tube. The branch pipes 16 rotate integrally with the heating tube 12 inside the heating tube 12. For this reason, the material in the heating tube 12 accumulates below the heating tube 12, but is repeatedly lifted up and dropped by the branch pipes 16 as the heating tube 12 rotates. For this reason, the material supplied into the heating tube 12 is gradually mixed as it flows gradually inside the heating tube 12 toward the second end 12b. In this embodiment, since the branch pipe 16 is cylindrical, the material M1 smoothly slides down from the branch pipe 16. Therefore, the material M1 is less likely to scatter inside the heating pipe 12.

[0037] On the other hand, the branch pipe 16 branches off from the inner cylinder 15 provided on the first end 12a side. A hot air supply pipe 17 is connected to the inner cylinder 15, and hot air is supplied to the inner cylinder 15. The inner cylinder 15 and the branch pipe 16 are sloped so that the first end 12a side is higher, just like the heating pipe 12. Therefore, the hot air supplied to the inner cylinder 15 rises from the inner cylinder 15 towards the branch pipe 16. The branch pipe 16 penetrates the support plate 12a2 arranged on the second end 12b side of the heating pipe 12, and opens into the exhaust duct 20. Therefore, the hot air atmosphere is released into the exhaust duct 20.

[0038] The exhaust duct 20 is preferably configured so that gas does not flow into the heating chamber 25. In this embodiment, an exhaust fan 21a is provided downstream of the exhaust port 21. This maintains a lower pressure inside the exhaust duct 20 than inside the heating chamber 25, preventing gas from flowing from the exhaust duct 20 into the heating chamber 25. In this embodiment, the branch pipe 16 extends from the first end 12a of the heating pipe 12 to the outside of the heating pipe 12, and the exhaust duct 20 covering the outlet of the branch pipe 16 is provided outside the first end 12a of the heating pipe 12. Therefore, hot air exhausted through the branch pipe 16 is exhausted through the exhaust duct 20. In the exhaust duct 20, the atmospheric gas and combustion gas in the heating chamber 25 may mix. However, the mixed gas is unlikely to flow into the heating chamber 25. In the heating pipe 12, the branch pipe 16 separates the flow path of the hot air atmosphere. Therefore, the atmospheric gas in the heating pipe 12 and the hot air atmosphere passing through the branch pipe 16 are unlikely to mix in the heating chamber 25, and the powder material in the heating pipe 12 can be heated in an appropriate atmosphere. The drain 22 is preferably provided with a lid or a valve, and is preferably configured to prevent outside air from flowing into the exhaust duct 20 from the drain 22 during normal operation.

[0039] As the heating pipe 12 rotates, the material M1 flows toward the second end 12b while being repeatedly lifted and dropped by the branch pipes 16. At this time, the material M1 receives heat from the branch pipes 16 and is gradually heated. Furthermore, a plurality of branch pipes 16 are provided in the heating pipe 12 in the circumferential direction on the outer circumferential surface of the inner cylinder 15, each branching from the inner cylinder 15 and extending in the axial direction along the inner circumferential surface of the heating pipe 12. Therefore, the contact area between the material M1 flowing through the heating pipe 12 and the branch pipes 16 is large, and the material M1 is heated in a short time. For example, when used to dry the material M1, the time required for drying is shortened.

[0040] This embodiment also includes a heating chamber 25 having a tunnel-shaped furnace body 27 in which a heater 26 is arranged, and the heating pipe 12 passes through the furnace body 27 and is rotatably supported. This stabilizes the temperature outside the heating pipe 12. For example, in this embodiment, the tunnel-shaped furnace body 27 is provided with a partition 28. The interior of the furnace body 27 is divided by the partition 28 into three spaces A1 to A3 in the insertion direction.

[0041] Furthermore, the first end 12a side of the heating pipe 12 protrudes from the heating chamber 25 and extends outward. The temperature of the hot air flowing through the branch pipe 16 gradually decreases from the second end 12b side toward the first end 12a side. Therefore, the temperature of a portion A4 of the heating pipe 12 protruding from the heating chamber 25 and extending outward on the first end 12a side is lower than that of other portions of the heating chamber 25. Furthermore, the portion A4 is the portion into which material is fed from the screw feeder 40, and can serve as a preheating region where the material fed from the screw feeder 40 is gradually heated.

[0042] The material is heated in the heating tube 12 in three spaces A1 to A3 within the heating chamber 25. In the portions of the spaces A1 to A3, the outside of the heating tube 12 is heated by the heater 26 provided in the furnace body 27. This makes it easy to adjust the temperature inside the heating tube 12 to an appropriate temperature. Therefore, the material is heat-treated while being adjusted to predetermined temperatures in stages in the three spaces A1 to A3 within the heating chamber 25. Furthermore, the second end 12b of the heating tube 12 extends outward, protruding from the heating chamber 25. In this embodiment, the branch pipe 16 branches off from the inner tube 15 at the point where the heating tube 12 enters the furnace body 27 as viewed from the second end 12b. Therefore, in the portion A5 of the second end 12b of the heating tube 12 protruding from the heating chamber 25, the material M1 is only subjected to heat from the inner tube 15. As a result, the temperature of the material M1 gradually decreases. Therefore, the material discharged from the heating pipe 12 to the casing 51 in the material recovery section 14 is cooler than the material inside the furnace body 27 and has a temperature that makes it easy to process in the subsequent process. In this embodiment, the heating chamber 25 is provided outside the heating pipe 12, but the heating chamber 25 does not have to be provided unless otherwise specified.

[0043] Hot air is supplied from the second end 12b of the heating tube 12 through the inner tube 15 and the branch pipe 16. The temperature of the hot air gradually decreases from the second end 12b of the heating tube 12 toward the first end 12a. Meanwhile, the material is supplied to the first end 12a and gradually flows toward the second end 12b. The material is supplied to the first end 12a and gradually heats up as it contacts the branch pipe 16 and moves toward the second end 12b. For example, if material M1 is to be heated to 350°C inside the heating tube 12, the branch pipe 16 should be set to a predetermined temperature within the heating tube 12. Because material M1 is heated by direct contact with the branch pipe 16 inside the heating tube 12, it is heated to the predetermined temperature in a relatively short time. This shortens the residence time within the heating tube 12. Furthermore, there is a portion A5 on the second end 12b side of the heating tube 12 where material M1 does not directly contact the branch pipe 16, and the material cools easily in this portion. Therefore, the material M1 is discharged in a cooler state than the state inside the furnace body 27, making it easier to handle in subsequent processes.

[0044] As described above, this embodiment includes the heating pipe 12, the material supply unit 13, the material recovery unit 14, the inner cylinder 15, the branch pipes 16, the hot air supply pipe 17, and the drive mechanism 18. Here, the heating pipe 12 is a substantially cylindrical pipe in which the first end 12a side is positioned higher than the second end 12b side. The material supply unit 13 is provided on the first end 12a side of the heating pipe 12. The material recovery unit 14 is provided on the second end 12b side of the heating pipe 12. The inner cylinder 15 is a cylinder supported by the heating pipe 12 in a state where it is inserted into the center of the heating pipe 12 at the second end 12b side of the heating pipe 12. A plurality of branch pipes 16 are provided in the heating pipe 12 in the circumferential direction on the outer peripheral surface of the inner cylinder 15. Each branch pipe 16 branches off from the inner cylinder 15 and extends axially along the inner peripheral surface of the heating pipe 12. The hot air supply pipe 17 is inserted into one end of the inner cylinder 15 extending outside the heating pipe 12 and is supported so as to be rotatable relative to the inner cylinder 15. A drive mechanism 18 rotates the heating pipe 12, the inner cylinder 15, and the branch pipe 16 integrally.

[0045] In the rotary kiln 10, the material M1 supplied from the material supply section 13 to the first end 12a of the heating tube 12 flows through the heating tube 12 toward the second end 12b, where it comes into contact with the branch pipe 16 and is mixed and heated, as shown in FIG. 9 . This allows for efficient heat transfer to the material M1, enabling the material M1 to be dried or fired in a short time. Furthermore, the hot air passes through the inner tube 15 and the branch pipe 16 and does not mix with the ambient gas within the heating tube 12. Therefore, an atmosphere (e.g., an N2 atmosphere) suitable for heat treatment of the material M1 can be created within the heating tube 12. Furthermore, heating of the material M1 is suppressed near the second end 12b relative to the branch pipe 16 branch point. Therefore, the material M1 is discharged with a slightly lower temperature.

[0046] Preferably, a cylinder is used for the branch pipe 16. This prevents the material M1 from scattering inside the heating pipe 12. Preferably, a cylinder is used for the inner cylinder 15. This forms a space of a predetermined depth between the inner circumferential surface of the heating pipe 12 and the inner cylinder 15. By adjusting the depth at which the material M1 flows through this space, the material M1 can flow without coming into contact with the inner cylinder 15. This more reliably prevents the heating of the material M1 on the second end 12b side of the position at which the branch pipe 16 branches.

[0047] FIG. 10 is a longitudinal sectional front view of a rotary kiln 10A. In this embodiment, the branch pipes 16 of the rotary kiln 10A extend outside the heating pipes 12 at their intermediate portions. An exhaust duct 20A is disposed at the intermediate portion of the heating pipes 12 so as to cover the outlets of the branch pipes 16 extending outside the heating pipes 12. In the embodiment shown in FIG. 10, the exhaust duct 20A is a ring-shaped duct that is continuous in the circumferential direction at the intermediate portion of the heating pipes 12. An exhaust port 21A for exhausting the recovered hot air atmosphere is provided at the upper portion of the exhaust duct 20A. In the embodiment shown in FIG. 10, supports 63 and 64 are provided to support the tip portions of the branch pipes 16. The supports 63 and 64 may each have arms extending radially from the center of the heating pipe 12, similar to the supports 61 and 62 described above (see FIGS. 6 and 7). In this case, the branch pipe 16 extends to the middle of the heating pipe 12, but further to the first end 12a side, the heating pipe 12 does not have the branch pipe 16. In the preheating zone A4 on the first end 12a side, the material supplied from the screw feeder 40 is slowly heated before hitting the branch pipe 16.

[0048] In the embodiment shown in FIG. 10 , the branch pipe 16 extends outside at the intermediate portion of the heating pipe 12, so that there is no room for the hot air atmosphere flowing through the branch pipe 16 to enter the heating pipe 12. Preferably, the branch pipe 16 is located at the intermediate portion of the heating pipe 12, penetrates the heating pipe 12 while maintaining the airtightness of the heating pipe 12, and extends outside the heating pipe 12. In this case, the hot air atmosphere does not mix with the atmospheric gas inside the heating pipe 12, making it easier to stabilize the atmospheric gas inside the heating pipe 12. Furthermore, in the embodiment shown in FIG. 10 , the atmospheric gas inside the heating pipe 12 recovered from the exhaust duct 20 on the first end 12a side of the heating pipe 12 and the hot air atmosphere discharged from the branch pipe 16 and recovered by the exhaust duct 20A may each be sent to a heat exchanger 70 for heat exchange. The atmospheric gas heated in the heat exchanger 70 may then be supplied to the heating pipe 12 from the second end 12b side. In addition, the hot air atmosphere that has been wasted heat in the heat exchanger 70 may be supplied again to the hot air generator 60 and supplied from the inner cylinder 15 to the branch pipe 16. This may improve the thermal efficiency of the rotary kiln 10A.

[0049] FIG. 11 is a longitudinal front view of a rotary kiln 10B. FIG. 12 is a cross-sectional view taken along the line XII-XII of FIG. 11. In this embodiment, the rotary kiln 10B includes a manifold 81 disposed at the center of the heating tube 12 and connected to a branch pipe 16, and at least one exhaust pipe 82 extending from the manifold 81 to the outside of the heating tube 12. In this embodiment, the manifold 81 is a cylindrical body closed at both ends. The branch pipe 16 extends axially along the inner circumferential surface of the heating tube 12 and is bent inward and connected to the outer circumferential surface of the manifold 81 so as to connect to the inside of the manifold 81. In this embodiment, as shown in FIG. 12, the manifold 81 is provided with four exhaust pipes 82. The four exhaust pipes 82 are evenly spaced around the manifold 81, extend radially outward from the manifold 81, and penetrate the heating tube 12. The ends of the exhaust pipes 82 are bent in the opposite direction to the rotational direction of the heating tube 12 and open. 12, the heating pipe 12 rotates counterclockwise (left-handed), while the tip of the exhaust pipe 82 is bent to the right. This allows hot air to be smoothly exhausted from the exhaust pipe 82 in accordance with the rotation of the heating pipe 12.

[0050] The exhaust duct 20B is configured as a ring-shaped duct that continues in the circumferential direction at the middle of the heating pipe 12 so as to cover the tip of the exhaust pipe 82 on the outside of the heating pipe 12. An exhaust port 21B that exhausts the recovered hot air atmosphere is provided at the top of the exhaust duct 20B. In this case as well, in the preheating region A4 on the first end 12a side, the material supplied from the screw feeder 40 is slowly heated before hitting the branch pipe 16. In addition, since the manifold 81 is provided, chattering and the like that occurs in the branch pipe 16 due to the supply of hot air to the branch pipe 16 can be suppressed.

[0051] In the rotary kiln 10 described above, the temperatures of the various components vary greatly during operation. For example, the heater 26 heats the heating tube 12 from the outside at the portion located inside the furnace body 27. This causes the temperature of the portion located inside the furnace body 27 to be higher than that of the portion located outside the furnace body 27. Inside the heating tube 12, hot air flows through the inner tube 15 and the branch pipes 16, causing the heating tube 12 to be heated by the hot air. The manifold 81 and the exhaust pipe 82 are also heated by the hot air. The temperature of the hot air flowing through the inner tube 15 and the branch pipes 16 gradually decreases. Thus, the temperatures of the heating tube 12, the inner tube 15, the branch pipes 16, and the like fluctuate during operation depending on the operating environment. Therefore, during operation, the heating tube 12, the inner tube 15, and the branch pipes 16 thermally expand depending on the operating environment of each component. The heating pipe 12, the inner cylinder 15 and the branch pipe 16 each have a tubular structure, and therefore expand in the radial and longitudinal directions due to thermal expansion.

[0052] Thus, during operation, the length and diameter of each component of the rotary kiln 10 may change compared to before use. The larger the size of the rotary kiln 10, the greater the dimensional changes due to thermal expansion. Under these circumstances, if the components of the rotary kiln 10 are fixed by welding or other means, the difference in elongation of each component due to thermal expansion cannot be absorbed, and distortion accumulates at the joints, which may cause malfunction. Below, we will explain an example of the structure of the rotary kiln 10 that takes into account the thermal expansion of each component.

[0053] For example, the inner cylinder 15 of the rotary kiln 10 may be supported relative to the heating pipes 12 via springs. In this case, even if a dimensional difference occurs between the inner cylinder 15 and the heating pipes 12 due to thermal expansion, the inner cylinder 15 is supported relative to the heating pipes 12 via the springs 101, and therefore, it is acceptable for the portion where the inner cylinder 15 is attached to the heating pipes 12 to be displaced relative to each other. Various structures may be employed for supporting the inner cylinder 15 relative to the heating pipes 12 via the springs 101.

[0054] Figures 13 and 14 are longitudinal sectional front views of a rotary kiln 10C. Of these, Figure 13 shows the structure of the end portion on the first end 12a side of the heating tube 12. Figure 14 shows the structure of the end portion on the second end 12b side of the heating tube 12. Figure 15 is a view taken along the XV-XV arrow in Figure 14. Figure 15 shows the end portion on the first end 12a side of the heating tube 12.

[0055] <First Spring 101> In this embodiment, as shown in FIGS. 14 and 15 , the inner cylinder 15 is supported via a first spring 101 provided at an end portion of the heating pipe 12 on the second end 12b side. The first spring 101 is composed of a plurality of spring materials 101a arranged intermittently in the circumferential direction. In this embodiment, the plurality of spring materials 101a each extend from the inner cylinder 15 along the radial direction of the heating pipe 12. Specifically, a bracket 104 is attached to the outer periphery of the inner cylinder 15. The bracket 104 is provided with attachment portions for attaching one ends of the plurality of spring materials 101a. In this embodiment, eight spring materials 101a are arranged evenly in the circumferential direction. Each of the spring materials 101a is composed of a leaf spring. The spring materials 101a are arranged such that a flat surface of the leaf spring faces the axial direction of the heating pipe 12 and along the radial direction of the heating pipe 12. A middle portion 101a1 in the longitudinal direction of the spring material 101a is curved.

[0056] When the position of the inner cylinder 15 shifts with respect to the heating pipe 12 and the distance over which the spring material 101a is attached increases, the curved middle portion of the spring material 101a stretches. When the position of the inner cylinder 15 shifts with respect to the heating pipe 12 and the distance over which the spring material 101a is attached decreases, the middle portion curves and returns to its original shape.

[0057] When a dimensional change occurs between the heating tube 12 and the inner tube 15 due to thermal expansion, the end of the heating tube 12 on the second end 12b side shifts relative to the inner tube 15. For example, when the heating tube 12 elongates due to thermal expansion, the end of the heating tube 12 on the second end 12b side shifts in the axial direction relative to the inner tube 15, and the greater the thermal expansion, the greater the shift. In this embodiment, the inner tube 15 is connected via a first spring 101 provided at the end of the heating tube 12 on the second end 12b side. Therefore, even if a dimensional change occurs between the heating tube 12 and the inner tube 15 due to thermal expansion during use and a shift occurs at the connection portion, the inner tube 15 and the heating tube 12 are maintained in a connected state. Furthermore, because the inner tube 15 is connected via the first spring 101 provided at the end of the heating tube 12 on the second end 12b side, large distortion is unlikely to occur at the connection portion between the inner tube 15 and the heating tube 12.

[0058] In this embodiment, the inner tube 15 is further connected to the heating tube 12 by a plurality of spring materials 101a arranged intermittently in the circumferential direction. Therefore, during use, the inner tube 15 is likely to be maintained at the center of the heating tube 12. Furthermore, in this embodiment, the plurality of spring materials 101a each extend from the inner tube 15 along the radial direction of the heating tube 12. Therefore, during use, the inner tube 15 receives elastic reaction forces from the spring materials 101a in the circumferential direction, and is well balanced, thereby being maintained at the center of the heating tube 12. Furthermore, in this embodiment, it is preferable that each of the plurality of spring materials 101a be formed as a leaf spring with a curved intermediate portion in the length direction along the radial direction. By expanding and contracting the curved intermediate portion, even if the position of the inner tube 15 is displaced relative to the heating tube 12 due to thermal expansion, the displacement is absorbed. From this perspective, it is preferable that the spring material 101a connecting the heating tube 12 and the inner tube 15 has a required rigidity (elasticity). Furthermore, since the spring material 101a is used inside the heating tube 12, it is preferable that the spring material 101a has a required heat resistance and a required corrosion resistance against the atmosphere inside the heating tube 12.

[0059] In this embodiment, even if the position of the inner tube 15 is shifted relative to the heating tube 12 due to thermal expansion, the inner tube 15 is maintained at the center of the heating tube 12. Therefore, for example, the inner tube 15 is less likely to shift relative to the hot air supply pipe 17 that is fixedly disposed along the central axis of the heating tube 12.

[0060] FIG. 16 is a longitudinal sectional front view showing the connection structure between the inner cylinder 15 and the hot air supply pipe 17. In this embodiment, as shown in FIG. 16, the inner cylinder 15 is inserted into a pipe 110 provided at the opening 55 of the material recovery section 14. The pipe 110 may be made of a flexible pipe. A thermal insulation pipe 112 is attached to the outer periphery of the inner cylinder 15. A gland seal 113 is attached to the connection between the pipe 110 and the thermal insulation pipe 112. The thermal insulation pipe 112 is attached to the pipe 110 via a cam follower 114. The cam follower 114 rotatably supports the inner cylinder 15 and the thermal insulation pipe 112 relative to the pipe 110 of the material recovery section 14. Furthermore, because the pipe 110 is made of a flexible pipe, even if the inner cylinder 15 expands relative to the opening 55 of the material recovery section 14 due to thermal expansion, any misalignment in the connection position is absorbed.

[0061] A flange 115 is provided at the end of the inner cylinder 15, and a cylindrical first cover 121 is attached to it. On the other hand, a cylindrical second cover 122 is attached to the hot air supply pipe 17 that is inserted into the inner cylinder 15. The second cover 122 has a smaller outer diameter than the first cover 121 attached to the end of the inner cylinder 15, and is inserted inside the first cover 121. A gland seal 123 is attached between the first cover 121 and the second cover 122. A flange 126 is provided at the base end of the hot air supply pipe 17. A flexible pipe 127 is attached to the flange 126. A flange 122a is provided at the end of the second cover 122, and the flexible pipe 127 is connected to it. Since the second cover 122 and the hot air supply pipe 17 are connected via a flexible pipe 127, even if the inner tube 15 expands due to thermal expansion and the end of the inner tube 15 shifts relative to the hot air supply pipe 17, the shift is absorbed.

[0062] A shaft 128 extending axially outward from the first cover 121 is attached to the flange 122a of the second cover 122. The shaft 128 is attached intermittently in the circumferential direction, and a cam follower 129 is attached to the tip of the shaft 128. The cam follower 129 abuts against the outer periphery of the first cover 121 and rotatably supports the first cover 121. A duct 130 is provided around the joint between the first cover 121 and the second cover 122.

[0063] As shown in FIG. 13 , the rotary kiln 10C includes a manifold 81 to which ends of the branch pipes 16 are connected at the first ends 12a of the heating pipes 12. The manifold 81 is disposed in the center of the heating pipes 12. In this embodiment, the manifold 81 is a member having a double-pipe structure. An exhaust space 81c to which the branch pipes 16 are connected is provided between the inner pipe 81a and the outer pipe 81b of the manifold 81. The front and rear ends of the manifold 81 are closed. An exhaust pipe 82 extending radially is provided from the outer pipe 81b of the manifold 81. The exhaust pipe 82 extends outside the heating pipe 12 through a through-hole formed in the heating pipe 12. FIG. 17 is a view taken along arrows XVII-XVII in FIG. 13 . In other words, FIG. 17 is a left side view of the end of the manifold 81 as viewed from the first ends 12a of the heating pipes 12 along the axial direction of the heating pipes 12. A plurality of exhaust pipes 82 (six in the example shown in FIG. 17) are provided in the circumferential direction. In this manner, the manifold 81 preferably has at least one exhaust pipe 82 extending from the manifold 81 to the outside of the heating pipe 12.

[0064] As shown in FIG. 17 , in this embodiment, the manifold 81 is supported by the heating pipe 12 via second springs 102. The second springs 102 are composed of a plurality of spring materials 102a arranged intermittently in the circumferential direction. In the embodiment shown in FIG. 17 , six spring materials 102a are arranged evenly in the circumferential direction of the manifold 81. The six spring materials 102a constituting the second spring 102 each extend from the inner cylinder 15 along the radial direction of the heating pipe 12. Each spring material 102a is composed of a leaf spring whose intermediate portion 102a1 in the length direction along the radial direction is curved. The flat surface of the spring material 102a faces the axial direction of the heating pipe 12. In this embodiment, one end of the spring material 102a is attached to the end of the manifold 81 on the first end side. The six spring materials 102a are arranged between the six exhaust pipes 82 in the circumferential direction of the manifold 81. The end of the spring material 102a may be attached with a fastening member such as a bolt and nut. If a bolt and nut is used, it is preferable that the bolt and nut have a locking function. The end of the spring material 102a may be fastened with the bolt and nut, and the bolt and nut may be welded to each other to prevent the bolt and nut from loosening.

[0065] As shown in Fig. 13 and Fig. 17, the branch pipe 16 is preferably connected to a manifold 81. Furthermore, the manifold 81 is preferably connected to the heating pipe 12 via a second spring 102. The manifold 81 is connected to the heating pipe 12 via the second spring 102. Therefore, even if dimensional changes occur in the heating pipe 12 and the manifold 81 due to thermal expansion during use and a displacement occurs at the connection portion, the manifold 81 and the heating pipe 12 are maintained in a connected state. Furthermore, because the manifold 81 is connected via the second spring 102 provided on the heating pipe 12, large distortion is unlikely to occur at the connection portion between the manifold 81 and the heating pipe 12.

[0066] In this embodiment, the manifold 81 is further connected to the heated pipe 12 by a plurality of spring materials 102a arranged intermittently in the circumferential direction. Therefore, during use, the manifold 81 is likely to be maintained at the center of the heated pipe 12. Furthermore, in this embodiment, the plurality of spring materials 102a each extend from the manifold 81 along the radial direction of the heated pipe 12. Therefore, during use, the manifold 81 receives an elastic reaction force from each of the spring materials 102a in the circumferential direction, and is maintained at the center of the heated pipe 12 by a well-balanced force. Furthermore, in this embodiment, the plurality of spring materials 101a each may be configured as a leaf spring with a curved intermediate portion in the length direction along the radial direction. By expanding and contracting the curved intermediate portion, even if the position of the manifold 81 is displaced relative to the heated pipe 12 due to thermal expansion, the displacement is absorbed. From this perspective, the spring material 102a connecting the heated pipe 12 and the manifold 81 preferably has a required rigidity (elasticity). Furthermore, since the spring material 102 a is used inside the heating tube 12 , it is preferable that the spring material 102 a has a required heat resistance and a required corrosion resistance against the atmosphere inside the heating tube 12 .

[0067] In this embodiment, the inner cylinder 15 is connected via a first spring 101 provided at the end of the second end side of the heating pipe 12. The manifold 81 is connected to the heating pipe 12 via a second spring 102. The first spring 101 is stronger than the second spring 102. movableThe width is large. In this embodiment, the first spring 101 is made of a spring material 101a whose intermediate portion in the length direction along the radial direction of the heating pipe 12 is curved. The second spring 102 is made of a spring material 102a whose intermediate portion in the length direction along the radial direction of the heating pipe 12 is curved. The spring material 101a constituting the first spring 101 is curved more than the spring material 102a constituting the second spring 102. As a result, the end portion on the second end side of the heating pipe 12 moves more than the connection portion on the first end side of the heating pipe 12 to which the end portion of the manifold 81 is connected, thereby absorbing thermal expansion of the heating pipe 12. In other words, the movement of the end portion of the manifold 81 relative to the heating pipe 12 is kept small. As a result, the movement of the exhaust pipe 82 inserted into the heating pipe 12 is kept small, and distortion occurring in the portion where the exhaust pipe 82 is inserted is kept small.

[0068] In this embodiment, the spring material 101a attached to the end of the heating tube 12 has a flat surface of the leaf spring facing the axial direction of the heating tube 12. Similarly, the spring material 102a attached to the end of the manifold 81 has a flat surface facing the axial direction of the heating tube 12. Therefore, when the heating tube 12 rotates, the material to be fired in the heating tube 12 is not easily stirred up by the spring material 101a and the spring material 102a. In contrast, the flat surface of the leaf spring may be intentionally inclined with respect to the axial direction of the heating tube 12 so that the material to be fired in the heating tube 12 is stirred up by the spring material 101a and the spring material 102a when the heating tube 12 rotates. From the viewpoint of stirring up the material to be fired in the heating tube 12, the spring material 101a, the spring material 102a, and the flat surface of the leaf spring may be oriented along the axial direction of the heating tube 12. This allows the material to be fired to be wound up inside the heating tube 12 as needed, making it easier to fire the material to be fired uniformly. The orientations of the spring material 101a and the spring material 102a may be different. Although curved leaf springs are exemplified as the spring material 101a and the spring material 102a here, the spring material 101a and the spring material 102a may be any material that elastically supports the inner tube 15 and the manifold 81 relative to the heating tube 12. From this perspective, the spring material 101a and the spring material 102a are not limited to the leaf spring form described above.

[0069] <Exhaust pipe 82> FIG. 18 is a side view showing the mounting structure of the exhaust pipe 82. Note that in FIG. 18, the portion of the manifold 81 where the exhaust pipe 82 is inserted is partially cross-sectionally depicted. In this embodiment, the exhaust pipe 82 is inserted into a through-hole 12c formed in the middle of the heating pipe 12. The manifold 81 also has a socket 81d into which the exhaust pipe 82 is inserted. The socket 81d is connected to the space 81c of the manifold 81. The exhaust pipe 82 is inserted into the socket 81d provided in the manifold 81. The exhaust pipe 82 is inserted into the socket 81d of the manifold 81, and is inserted into the through-hole 12c with respect to the heating pipe 12. Therefore, even if the exhaust pipe 82 expands due to thermal expansion, it does not interfere with the heating pipe 12.

[0070] In this embodiment, the exhaust pipe 82 is a tubular member. The end 82a of the exhaust pipe 82 that is inserted into the socket 81d has a thread formed on its outer circumferential surface, and the socket 81d also has a thread formed on its inner circumferential surface. The end 82a of the exhaust pipe 82 is connected to the socket 81d using a threaded structure. When the exhaust pipe 82 expands due to thermal expansion, the exhaust pipe 82 expands in the radial direction of the manifold 81. This makes it difficult for distortion to occur at the connection between the exhaust pipe 82 and the manifold 81. The exhaust pipe 82 is covered by an exhaust duct 20C. An exhaust port 21C is provided at the top of the exhaust duct 20C. A suction pipe is attached to the exhaust port 21C, and a negative pressure is maintained inside the exhaust duct 20C. The exhaust duct 20C is configured to collect exhaust air from the exhaust pipe 82.

[0071] In this embodiment, a seal 140 is provided in the through hole 12c of the heating tube 12 through which the exhaust pipe 82 is inserted. The seal 140 can allow the exhaust pipe 82 to shift relative to the through hole 12c due to thermal expansion and can prevent the atmosphere inside the heating tube 12 from leaking to the outside through a gap between the exhaust pipe 82 and the through hole 12c. A retaining mechanism for the socket 81d may be provided in accordance with the structure of the seal 140. In this embodiment, various structures such as a mechanical seal or a gland packing may be employed for the seal 140. This prevents the atmosphere inside the heating tube 12 from leaking into the exhaust duct 20C. The seal 140 allows thermal expansion of the exhaust pipe 82 in the radial direction relative to the manifold 81. The seal 140 also prevents the powdered fired material and atmospheric gas inside the heating tube 12 from moving between the inside and outside of the through hole 12c. The seal 140 prevents the powdered burned material and atmospheric gases from inside the heating tube 12 from entering the exhaust pipe 82, and the gases inside the exhaust pipe 82 are exhausted through the exhaust duct 20C.

[0072] Furthermore, an outer casing 142 may be attached to the exhaust pipe 82 via a bellows 141. The bellows 141 has a larger diameter than the exhaust pipe 82 and surrounds the through-hole 12c of the heating pipe 12. Therefore, the bellows 141 surrounds the exhaust pipe 82 exposed from the through-hole 12c of the heating pipe 12. The outer casing 142 is attached to the tip of the bellows 141. Even if the exhaust pipe 82 expands due to thermal expansion, the exhaust pipe 82 is allowed to extend outside the heating pipe 12 because it passes through the through-hole 12c of the heating pipe 12. Because the exhaust pipe 82 is surrounded by the bellows 141 and the outer casing 142 is attached via the bellows 141, even if the exhaust pipe 82 expands, it does not interfere with the exhaust duct 20C. In this way, the rotary kiln 10 preferably has a structure that allows for expansion of the exhaust pipe 82 due to thermal expansion and dimensional changes in the outer diameter.

[0073] In this embodiment, the end of the exhaust pipe 82 is surrounded by a bellows 141, but the bellows 141 may be omitted and the exhaust pipe 82 may be inserted into the through-hole 12c of the heating pipe 12 via a seal 140.

[0074] FIG. 19 is a side view showing another embodiment of the support structure for the branch pipes 16. As shown in FIG. 19, the support structure 160 for the branch pipes 16 includes a ring 161 and a positioning member 162. The ring 161 is an annular member arranged along the inside of the branch pipes 16. The positioning member 162 is a member provided on the ring 161 and positions each of the branch pipes 16. The support structure 160 is preferably attached intermittently in the longitudinal direction of the branch pipes 16. This maintains the position of each branch pipe 16 within the heating pipe 12. This can prevent the branch pipes 16 from bending significantly toward the inside of the heating pipe 12. In the support structure 160, the ring 161 preferably has a required rigidity. The ring 161 may be, for example, a short cylindrical pipe.

[0075] Furthermore, a bracket 170 is attached to the branch pipe 16. The bracket 170 has a base portion 171 and a rising portion 172. The base portion 171 is a portion that is disposed along the inner circumferential surface of the heating pipe 12. The rising portion 172 is a portion that rises from the base portion 171 along the radial direction of the heating pipe 12. The rising portion 172 may have an insertion hole 173 through which the branch pipe 16 is inserted. The branch pipe 16 may be attached to the heating pipe 12 in a state where it is inserted into the insertion hole 173 of the bracket 170. The insertion hole 173 of the rising portion 172 is an elongated hole that is long along the radial direction of the heating pipe 12. The base portion 171 of the bracket 170 is welded to the inner circumferential surface of the heating pipe 12. The bracket 170 may be attached to some of the multiple branch pipes 16.

[0076] In this embodiment, the circumferential spacing between the multiple branch pipes 16 is maintained by the above-described rings 161 and positioning members 162. Furthermore, some of the multiple branch pipes 16 are attached to the heating pipe 12 via brackets 170. The branch pipes 16 rotate in stable positions within the heating pipe 12. Furthermore, the insertion holes 173 of the brackets 170, through which the branch pipes 16 are inserted, are elongated holes that are long along the radial direction of the heating pipe 12. Because the insertion holes 173 of the brackets 170 are elongated holes, dimensional errors that occur during the manufacturing process of the heating pipes 12 and the branch pipes 16 can be absorbed during assembly, making it easier to assemble the rotary kiln 10.

[0077] Although the invention disclosed herein has been described in detail above, these are merely examples and do not limit the scope of the claims. Furthermore, the disclosure herein can be modified in various ways, and as long as no particular problem arises, each component and each process mentioned herein can be omitted or combined as appropriate.

[0078] As described above, this specification includes the disclosures set forth in the following sections. Section 1: A substantially cylindrical heating tube; a material supply unit provided on a first end side of the heating tube; a material recovery section provided on a second end side of the heating tube; an inner cylinder supported in a state where it is inserted into a center part of the heating pipe at the second end side of the heating pipe; a plurality of branch pipes are provided in the heating pipe in a circumferential direction on an outer circumferential surface of the inner cylinder, the branch pipes branching off from the inner cylinder and extending in an axial direction along an inner circumferential surface of the heating pipe; a hot air supply pipe that is inserted into one end of the inner cylinder extending outside the heating pipe and supported so as to be rotatable relative to the inner cylinder; a drive mechanism that rotates the heating tube; Equipped with The inner cylinder is connected to the heating pipe via a spring. Rotary kiln.

[0079] Section 2: Item 2. The rotary kiln according to item 1, wherein the inner cylinder is connected via a first spring provided at an end of the heating pipe on the second end side.

[0080] Section 3: Item 3. The rotary kiln according to item 2, wherein the first spring is composed of a plurality of spring members arranged intermittently in the circumferential direction.

[0081] Section 4: Item 4. The rotary kiln according to item 3, wherein the plurality of spring materials constituting the first spring each extend from the inner cylinder along a radial direction of the heating pipe.

[0082] Section 5: Item 5. The rotary kiln according to item 4, wherein the plurality of spring materials constituting the first spring are each composed of a leaf spring whose intermediate portion in the length direction along the radial direction is curved.

[0083] Item 6: a manifold disposed in the center of the heating pipe and connected to the branch pipe; and at least one exhaust pipe extending from the manifold to the outside of the heating pipe, The manifold is connected to the heating pipe via a second spring. A rotary kiln according to any one of items 1 to 5.

[0084] Section 7: Item 7. The rotary kiln according to item 6, wherein the second spring is composed of a plurality of spring members arranged intermittently in the circumferential direction.

[0085] Section 8: Item 8. The rotary kiln according to item 7, wherein the plurality of spring materials constituting the second spring each extend from the inner cylinder along a radial direction of the heating pipe.

[0086] Section 9: Item 9. The rotary kiln according to item 8, wherein the plurality of spring materials constituting the second spring are each composed of a leaf spring whose intermediate portion in the length direction along the radial direction is curved.

[0087] Section 10: the inner cylinder is connected via a first spring provided at an end portion on a second end side of the heating pipe, a manifold disposed in the center of the heating pipe and connected to the branch pipe; and at least one exhaust pipe extending from the manifold to the outside of the heating pipe, the manifold is connected to the heating pipe via a second spring, The first spring is stronger than the second spring. movable Wide width, A rotary kiln according to any one of items 1 to 9.

[0088] Section 11: the first spring is made of a spring material whose intermediate portion in the length direction along the radial direction is curved, the second spring is made of a spring material whose intermediate portion in the length direction along the radial direction is curved, Item 11. The rotary kiln according to item 10, wherein the spring material constituting the first spring is curved more than the spring material constituting the second spring.

[0089] Section 12: a manifold disposed in the center of the heating pipe and connected to the branch pipe; and at least one exhaust pipe extending from the manifold to the outside of the heating pipe, Item 12. The rotary kiln according to any one of items 1 to 11, wherein the exhaust pipe is inserted into a through hole formed in an intermediate portion of the heating pipe and inserted into a socket provided in the manifold.

[0090] Section 13: Item 13. The rotary kiln according to item 12, wherein the exhaust pipe is a tubular member, and the end of the exhaust pipe inserted into the socket has a tapered shape that narrows toward the tip.

[0091] Section 14: Item 14. The rotary kiln according to item 12 or 13, wherein a seal is provided in the through hole of the heating pipe through which the exhaust pipe is inserted.

[0092] Section 15: a ring disposed along the inside of the plurality of branch pipes; a positioning member provided on the ring for positioning each of the plurality of branch pipes; A rotary kiln according to any one of items 1 to 14, comprising:

[0093] Section 16: A bracket is attached to the branch pipe, The bracket is a base portion disposed along an inner circumferential surface of the heating pipe; a rising portion rising from the base portion along the radial direction of the heating pipe; and The rising portion has an insertion hole through which the branch pipe is inserted. A rotary kiln according to any one of items 1 to 15.

[0094] Section 17: the insertion hole of the rising portion is an elongated hole that is long along the radial direction of the heating pipe, A rotary kiln as described in paragraph 16. [Explanation of symbols]

[0095] 10, 10A, 10B, 10C rotary kiln 12 Heating tube 12a 1st end 12a1 flange 12a2 Support plate 12b 2nd end 12b1 flange 12b2 Outlet 13 Material supply section 14 Material Recovery Department 15 Inner cylinder 15a 1st inner cylinder 15b 2nd inner cylinder 16 Branch pipe 16a End of branch pipe 16 17 Hot air supply pipe 18 Drive mechanism 18a chain sprocket 18f Chain 20, 20A, 20B, 20C Exhaust duct 21, 21A, 21B, 21C exhaust port 22 Drain 25 Heating chamber 26 Heater 27 Furnace body 28 Dividers 31 flange 32 flange 33 Ribs 36 Bearings 37 Bearings 38 Seals 39 Seals 40 Screw Feeder 41 Outlet 42 Sealing material 44 Aperture 46 Insulated pipe 48 Sealing material 51 Casing 52 Hopper 52a Valve 53 Inner cylinder cover 54 Aperture 55 Aperture 56 Insulated pipe 58 Sealing material 60 Hot air generator 61,62 Support 61a,62a Arm 63,64 Support 70 Heat exchanger 81 Manifold 81a Inner tube of manifold 81 81b Outer tube of manifold 81 81c Space for exhaust of manifold 81 81d socket 82 Exhaust pipe 82a End of exhaust pipe 82 101 First Spring 101a Spring material 101a1 Middle part of spring material 101a 102 Second spring 102a Spring material 102a1 Middle part of spring material 102a 104 Bracket 110 Pipe section 112 Insulated pipe 113 Grand Seal 114 Cam follower 115 flange at end of inner cylinder 15 122a Flange of second cover 122 123 Grand Seal 126 Flange of hot air supply pipe 17 127 Flexible Pipe 128 Shaft 129 Cam follower 130 Duct 131 Intake port of duct 130 140 stickers 141 Bellows 142 outer cylinder 160 Support structure for branch pipe 16 161 Ring 162 Positioning member 170 Bracket 171 Base 172 Rising part 173 Insertion hole M1 material

Claims

1. A substantially cylindrical heating tube; a material supply unit provided on a first end side of the heating tube; a material recovery section provided on a second end side of the heating tube; an inner cylinder supported in a state where it is inserted into a center part of the heating pipe at the second end side of the heating pipe; a plurality of branch pipes provided in the heating pipe in a circumferential direction on an outer circumferential surface of the inner cylinder, each branching from the inner cylinder and extending in an axial direction along an inner circumferential surface of the heating pipe; a hot air supply pipe that is inserted into one end of the inner cylinder extending outside the heating pipe and supported so as to be rotatable relative to the inner cylinder; a drive mechanism that rotates the heating tube; a manifold disposed at a center of the heating pipe and connected to the branch pipe; at least one exhaust pipe extending from the manifold to outside the heating pipe; Equipped with the inner cylinder is connected to the heating pipe via a spring, the exhaust pipe is inserted into a through hole formed in an intermediate portion of the heating pipe and inserted into a socket provided in the manifold. Rotary kiln.

2. 2. The rotary kiln according to claim 1, wherein the exhaust pipe is a tubular member, and the end of the exhaust pipe inserted into the socket has a tapered shape that narrows toward the tip.

3. The rotary kiln according to claim 1 , wherein a seal is provided in the through hole of the heating pipe through which the exhaust pipe is inserted.

4. A substantially cylindrical heating tube; a material supply unit provided on a first end side of the heating tube; a material recovery section provided on a second end side of the heating tube; an inner cylinder supported in a state where it is inserted into a center part of the heating pipe at the second end side of the heating pipe; a plurality of branch pipes provided in the heating pipe in a circumferential direction on an outer circumferential surface of the inner cylinder, each branching from the inner cylinder and extending in an axial direction along an inner circumferential surface of the heating pipe; a hot air supply pipe that is inserted into one end of the inner cylinder extending outside the heating pipe and supported so as to be rotatable relative to the inner cylinder; a drive mechanism that rotates the heating tube; a ring disposed along the inside of the plurality of branch pipes; a positioning member provided on the ring for positioning each of the plurality of branch pipes; Equipped with The inner cylinder is connected to the heating pipe via a spring. Rotary kiln.

5. A substantially cylindrical heating tube; a material supply unit provided on a first end side of the heating tube; a material recovery section provided on a second end side of the heating tube; an inner cylinder supported in a state where it is inserted into a center part of the heating pipe at the second end side of the heating pipe; a plurality of branch pipes provided in the heating pipe in a circumferential direction on an outer circumferential surface of the inner cylinder, each branching from the inner cylinder and extending in an axial direction along an inner circumferential surface of the heating pipe; a hot air supply pipe that is inserted into one end of the inner cylinder extending outside the heating pipe and supported so as to be rotatable relative to the inner cylinder; a drive mechanism that rotates the heating tube; Equipped with the inner cylinder is connected to the heating pipe via a spring, A bracket is attached to the branch pipe, The bracket is a base portion disposed along an inner circumferential surface of the heating pipe; a rising portion rising from the base portion along the radial direction of the heating pipe; and The rising portion has an insertion hole through which the branch pipe is inserted. Rotary kiln.

6. the insertion hole of the rising portion is an elongated hole that is long along the radial direction of the heating pipe, A rotary kiln according to claim 5.

7. A substantially cylindrical heating tube; a material supply unit provided on a first end side of the heating tube; a material recovery section provided on a second end side of the heating tube; an inner cylinder supported in a state where it is inserted into a center part of the heating pipe at the second end side of the heating pipe; a plurality of branch pipes provided in the heating pipe in a circumferential direction on an outer circumferential surface of the inner cylinder, each branching from the inner cylinder and extending in an axial direction along an inner circumferential surface of the heating pipe; a hot air supply pipe that is inserted into one end of the inner cylinder extending outside the heating pipe and supported so as to be rotatable relative to the inner cylinder; a drive mechanism that rotates the heating tube; a manifold disposed at a center of the heating pipe and connected to the branch pipe so as to be connected to the inside thereof; at least one exhaust pipe extending from the manifold to outside the heating tube; a first spring provided in the heating pipe and connected to the inner cylinder; a second spring provided on the heating pipe and connected to the manifold; Equipped with Rotary kiln.

8. The first spring has a larger movable range than the second spring.

8. The rotary kiln according to claim 7.

9. 8. The rotary kiln according to claim 7, wherein the first spring is composed of a plurality of spring materials arranged intermittently in the circumferential direction, each of which extends from the inner cylinder along the radial direction of the heating pipe, and which is composed of a leaf spring whose intermediate portion in the length direction along the radial direction is curved.

10. 8. The rotary kiln according to claim 7, wherein the second spring is composed of a plurality of spring materials arranged intermittently in the circumferential direction, each of which extends from the manifold along the radial direction of the heating pipe, and which is composed of a leaf spring having a curved intermediate portion in the length direction along the radial direction.

11. The first spring is composed of a plurality of spring materials arranged intermittently in the circumferential direction, each of which extends from the inner tube along the radial direction of the heating tube, and whose intermediate portions in the longitudinal direction along the radial direction are curved leaf springs; the second spring is configured by a plurality of spring materials that are arranged intermittently in a circumferential direction, extend from the manifold along a radial direction of the heating pipe, and are formed of leaf springs whose intermediate portions in a length direction along the radial direction are curved, The rotary kiln according to claim 7, wherein the spring material constituting the first spring is curved more than the spring material constituting the second spring.

12. a manifold disposed at a center of the heating pipe and connected to the branch pipe; at least one exhaust pipe extending from the manifold to outside the heating pipe; and 8. The rotary kiln according to claim 7, wherein the exhaust pipe is inserted into a through hole formed in an intermediate portion of the heating pipe and is inserted into a socket provided in the manifold.

13. 13. The rotary kiln according to claim 12, wherein the exhaust pipe is a tubular member, and the end of the exhaust pipe inserted into the socket has a tapered shape that narrows toward the tip.

14. The rotary kiln according to claim 12, wherein a seal is provided in the through hole of the heating pipe through which the exhaust pipe is inserted.

15. a ring disposed along the inside of the plurality of branch pipes; a positioning member provided on the ring for positioning each of the plurality of branch pipes; 8. The rotary kiln of claim 7, wherein

16. A bracket is attached to the branch pipe, The bracket is a base portion disposed along an inner circumferential surface of the heating pipe; a rising portion rising from the base portion along the radial direction of the heating pipe; and The rising portion has an insertion hole through which the branch pipe is inserted.

8. A rotary kiln according to claim 7.

17. the insertion hole of the rising portion is an elongated hole that is long along the radial direction of the heating pipe, 17. A rotary kiln according to claim 16.

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