Rotary kiln

Abstract

Effectively utilize the gas inside the heating tube. [Solution] The rotary kiln 1 comprises a cylindrical heating tube 10, a furnace body 20, a drive mechanism 30, a burner 40, and a ventilation path 50. The heating tube 10 has a transport space 10a formed inside through which the material to be processed A is transported. The furnace body 20 surrounds the heating tube 10. The furnace body 20 forms a heating space 20a between itself and the heating tube 10. The drive mechanism 30 rotates the heating tube 10 relative to the furnace body 20. The burner 40 heats the heating space 20a. The ventilation path 50 connects the transport space 10a and the heating space 20a.

Description

Technical Field

[0001] The present disclosure relates to a rotary kiln.

Background Art

[0002] Japanese Unexamined Patent Application Publication No. 2017-125104 discloses a pyrolysis apparatus including a drum, a heating furnace, a heating furnace temperature measurement unit, an outer wall surface temperature measurement unit, an inner wall surface temperature calculation unit, a workpiece temperature measurement unit, and a calculation unit. The heating furnace is provided outside the drum. A combustion furnace is provided outside the heating furnace. The combustion furnace is provided with a burner whose combustion amount of auxiliary fuel is controlled by a control device. In the heating furnace, the outer wall surface of the drum is heated by combustion exhaust gas discharged from the combustion furnace. The heating furnace is arranged in a cylindrical shape so as to cover the outer circumference of the drum and rotates together with the drum. The heating furnace temperature measurement sensor, the outer wall surface temperature measurement sensor, the inner wall surface temperature measurement sensor, and the workpiece temperature measurement sensor are arranged in alignment in a row (in the vertical direction in the form shown in FIG. 1). The calculation unit calculates the overall heat transfer coefficient based on the temperatures of the sensors arranged in alignment in a row. In the pyrolysis apparatus disclosed in Japanese Unexamined Patent Application Publication No. 2017-125104, the input amount of the workpiece is controlled based on the calculated overall heat transfer coefficient.

[0003] Japanese Patent No. 7125532 discloses a rotary kiln provided with a drive mechanism for rotating a heating pipe. A heat insulating pipe is attached to the end of the second end side (downstream side) of the heating pipe. A tire supported by a roller is attached to the outside of the heat insulating pipe. At the end of the second end side of the heating pipe, a gap with the first inner cylinder is open, which serves as a discharge port for discharging materials. In such a rotary kiln, the tire is attached to the first end side (upstream side) rather than the discharge port.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

[0005] Gas may be generated from the workpiece being heat-treated in the heating tube. [Means for solving the problem]

[0006] The rotary kiln disclosed herein comprises a cylindrical heating tube, a furnace body, a drive mechanism, a burner, and a ventilation path. The heating tube has a conveying space formed inside through which the material to be processed is transported. The furnace body surrounds the heating tube, forming a heating space between it and the heating tube. The drive mechanism rotates the heating tube relative to the furnace body. The burner heats the heating space. The ventilation path connects the conveying space and the heating space. With such a rotary kiln, the gas inside the heating tube is effectively utilized. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is a schematic diagram of rotary kiln 1. [Figure 2] Figure 2 is a longitudinal cross-sectional view of rotary kiln 1. [Figure 3] Figure 3 is a cross-sectional view taken along line III-III in Figure 1. [Figure 4] Figure 4 is a cross-sectional view taken along line IV-IV in Figure 1. [Modes for carrying out the invention]

[0008] Hereinafter, one embodiment of the present disclosure will be described in detail with reference to the drawings. In the following drawings, members and parts that perform the same function are denoted by the same reference numerals. Also, the dimensional relationships (length, width, thickness, etc.) in each figure do not reflect the actual dimensional relationships. The directions of up, down, left, right, front, and back are represented by the arrows U, D, L, R, F, and Rr in the figures, respectively. Hereinafter, the directions of up, down, left, right, front, and back are defined only for the convenience of explanation and do not limit the present invention unless otherwise specified.

[0009] Figure 1 is a schematic diagram of rotary kiln 1. In the figure, the direction in which the material to be processed A is transported is indicated by a white arrow. Figure 2 is a longitudinal cross-section of rotary kiln 1. Figure 3 is a cross-sectional view taken along line III-III of Figure 1. Figure 3 shows a cross-section of rotary kiln 1 viewed from the rear towards the front. Figure 4 is a cross-sectional view taken along line IV-IV of Figure 1. Figure 4 shows a cross-section of rotary kiln 1 viewed from the front towards the rear. In Figures 2 to 4, the material to be processed A is not shown.

[0010] <Rotary Kiln 1> As shown in Figure 1, the rotary kiln 1 comprises a heating tube 10, a furnace body 20, a drive mechanism 30, a burner 40, and a ventilation path 50. The rotary kiln 1 can be used for calcining a material A containing organic matter. Powdered material A can be calcined in the rotary kiln 1. The material A is processed in the heating tube 10 located inside the furnace body 20. The material A is not particularly limited, but can be organic matter such as food residue or plant fragments. Furthermore, the material A processed in the rotary kiln 1 may be in paste form, granular form, etc., and is not limited to powder form.

[0011] <Heating tube 10> The heating tube 10 is a roughly cylindrical tube. The heating tube 10 may be appropriately referred to as a "furnace core tube," etc. Inside the heating tube 10, a transport space 10a is formed in which the material to be processed A is transported. The heating tube 10 is rotationally driven by a drive mechanism 30, which will be described later, with a rotation axis set along the transport direction as its axis. The dimensions of the heating tube 10, such as its length and diameter, may be appropriately set according to the processing conditions of the material to be processed A. The heating tube 10 is a cylindrical tube so as to form a cylindrical transport space 10a inside, but it may be provided with flanges, etc., and may not be a perfect cylinder in all details. Both ends of the heating tube 10 (first end 11 and second end 12) are closed.

[0012] The heating tube 10 is required to have the necessary corrosion resistance depending on the material being heated and the ambient gas used during heating. Stainless steel (e.g., SUS316) can be used for the heating tube 10. Depending on the application, the heating tube 10 may be made of ceramic. The heating tube 10 may have a double-tube structure, for example, with an inner tube made of ceramic and an outer tube made of metal. The heating tube 10 may be provided with a gas supply pipe for supplying the ambient gas used when processing the material A to be processed. The heating tube 10 is inserted into the furnace body 20. On the upstream and downstream sides in the conveying direction, the heating tube 10 protrudes from the furnace body 20.

[0013] A material supply unit 70 is connected to the first end 11 of the heating tube 10. The material supply unit 70 is a device that supplies the material to be processed A into the heating tube 10. In this embodiment, the material supply unit 70 has a hopper 71 and a screw feeder 72. The hopper 71 contains the material to be processed A before firing. The material to be processed A before firing is supplied into the heating tube 10 by the screw feeder 72. The discharge port of the screw feeder 72 is inserted into the transport space 10a from the first end 11 of the heating tube 10. The first end 11 of the heating tube 10 through which the screw feeder 72 is inserted may be covered by a dust collection duct 73. The material supply unit 70 is not limited to the above-described form. A vibrating feeder, a chute, etc. may be used in the material supply unit 70.

[0014] An outlet 14a is provided on the second end 12 side of the heating tube 10. The workpiece A that has been fired inside the heating tube 10 is discharged from the outlet 14a. The outlet 14a may be provided on the portion of the heating tube 10 that protrudes from the furnace body 20, which will be described later.

[0015] In this embodiment, the discharge port 14a is formed on the side surface 14 of the heating tube 10. The discharge port 14a is a through hole formed on the side surface 14 of the heating tube 10. In this embodiment, the discharge port 14a has a substantially rectangular opening and is provided at multiple locations (six locations in this embodiment). The shape of the discharge port 14a is not particularly limited and may be circular, elliptical, or polygonal. The multiple discharge ports 14a are provided on the side surface 14 of the heating tube 10 at predetermined intervals along the circumferential direction. The material to be processed A that has reached the position where the discharge port 14a is formed can be discharged from the discharge port 14a that has reached the bottom of the multiple discharge ports 14a as the heating tube 10 rotates. Note that the opening pattern of the discharge ports when multiple discharge ports are formed on the side surface of the heating tube is not limited to the above-described form. The multiple discharge ports may be formed at different positions along the length of the heating tube. The multiple discharge ports may be arranged in a staggered pattern along the circumferential direction of the heating tube. The number of outlets is not particularly limited.

[0016] As shown in Figure 2, at the location where the discharge port 14a is provided, the heating tube 10 is surrounded by the recovery section 75. The discharge port 14a is connected to the recovery section 75. The recovery section 75 is connected to the furnace body 20.

[0017] <Furnace body 20> The furnace body 20 surrounds the heating tube 10. In the transport direction, the furnace body 20 is shorter than the heating tube 10, and the heating tube 10 is inserted into the furnace body 20. The outer surface of the heating tube 10 and the inner surface of the furnace body 20 are spaced apart. A heating space 20a is formed between the furnace body 20 and the heating tube 10. In other words, heating spaces 20a are formed above, below, and to the left and right of the heating tube 10.

[0018] The furnace body 20 can be composed of members having heat resistance and heat insulation properties. Although not particularly limited, the furnace body 20 can be composed of heat insulation members having heat resistance and heat insulation properties such as refractory bricks, refractory blocks, castable refractories, ceramic fiber boards, etc. The furnace body 20 has a rear wall 21, a front wall 22, a pair of side walls 23, 24, a bottom wall 25, and a ceiling wall 26. The thickness of each furnace wall is set to a required thickness such that the heat in the heating space 20a is sufficiently insulated. A partition 27 that divides the heating space 20a into a plurality of spaces along the conveying direction may be provided inside the furnace body 20. The periphery of the furnace body 20 may be covered with an outer wall made of metal (for example, stainless steel).

[0019] The bottom wall 25 and the side walls 23, 24 are substantially rectangular parallelepiped. As shown in FIG. 3, the width of the bottom wall 25 is larger than the outer diameter of the heating tube 10. A pair of side walls 23, 24 rise from the left and right ends of the bottom wall 25. The side wall 23 rises from the right end of the bottom wall 25. The side wall 24 rises from the left end of the bottom wall 25. The upper ends of the side walls 23, 24 reach approximately the central portion of the heating tube 10. A ceiling wall 26 is placed on the upper ends of the pair of side walls 23, 24. The ceiling wall 26 is semi-circular (arch-shaped). Both ends of the ceiling wall 26 are supported by the pair of side walls 23, 24. Note that the shape of the ceiling wall 26 is not particularly limited and may be formed horizontally (parallel to the bottom wall 25). A burner 40 is provided on the side wall 23.

[0020] The burner 40 is a device for heating the heating space 20a. A fuel supply pipe 41a extending from a fuel supply unit 41 and a combustion air supply pipe 42a extending from a combustion air supply unit 42 are connected to the burner 40. In the burner 40, the fuel gas (hydrocarbon, hydrogen, etc.) supplied from the fuel supply unit 41 and the combustion air supplied from the combustion air supply unit 42 are mixed and burned. In this embodiment, the combustion air supply pipe 42a is also connected to a heat exchanger 81 connected to an exhaust duct 26a on the upstream side. In the heat exchanger 81, the high-temperature air flowing from the exhaust duct 26a and the combustion air are heat-exchanged, whereby the combustion efficiency of the fuel gas and the combustion air can be improved.

[0021] In this embodiment, the burner 40 is provided in the furnace body 20 such that the fuel gas supplied from the fuel supply unit 41 is burned in the heating space 20a. In other words, the burner 40 is provided in the furnace body 20 so as to form combustion in the heating space 20a. For example, the burner 40 may be provided on the side wall 23 of the furnace body 20, and the nozzle 40a may extend into the furnace body 20. Flame is radiated from the burner 40 downward toward the heating pipe 10. Thereby, the heating pipe 10 is heated by the burner 40. The heating space 20a is heated by the burner 40 provided in the furnace body 20. The workpiece A is heated through the heating pipe 10 heated by the burner 40.

[0022] Although not shown, a temperature sensor is provided in the heating space 20a. As the temperature sensor, a thermocouple, an infrared thermometer, etc. may be used. The temperature sensor measures the temperature of the heating space 20a heated by the burner 40. The output of the burner 40 can be controlled according to the temperature of the heating space 20a. Thereby, the heating space 20a is heated to a preset temperature.

[0023] In this embodiment, an exhaust duct 26a is provided in the ceiling wall 26. The exhaust duct 26a is provided at a substantially central portion in the width direction of the furnace body 20 and at the highest position of the ceiling wall 26. As shown in FIG. 1, an exhaust device 80 is connected to the exhaust duct 26a. As the exhaust device 80, for example, a vacuum pump, an exhaust fan, etc. may be used. A heat exchanger 81, a bag filter, etc. may be connected between the exhaust duct 26a and the exhaust device 80.

[0024] As shown in FIG. 2, the rear wall 21 and the front wall 22 face each other in the front-rear direction. Through holes 21a and 22a are formed in the rear wall 21 and the front wall 22, respectively. The through holes 21a and 22a are substantially circular holes corresponding to the outer diameter of the heating pipe 10. The heating pipe 10 is inserted through the through holes 21a and 22a.

[0025] On the outer surface of the rear wall 21, a sealing member 21b is provided around the through hole 21a to seal the gap between the heating tube 10 and the rear wall 21. The sealing member 21b surrounds the heating tube 10 in the portion where the heating tube 10 protrudes from the rear wall 21.

[0026] Of the front wall 22, the portion 22b in which the through-hole 22a is formed protrudes forward. In other words, the through-hole 22a is formed in the portion 22b of the front wall 22 that protrudes forward. As shown in Figure 4, the portion 22b in which the through-hole 22a is formed is smaller than the dimensions of the furnace body 20 when viewed along the conveying direction, and is approximately the same shape as the furnace body 20 when viewed along the conveying direction. In this embodiment, the lower part 22b1 (the portion below the axis center of the heating tube 10) of the portion 22b in which the through-hole 22a is formed is approximately rectangular, and the upper part 22b2 (the portion above the axis center of the heating tube 10) is approximately semicircular.

[0027] As shown in Figure 2, the recovery section 75 (in this embodiment, the casing 76) is directly connected to the front end of the portion 22b of the front wall 22 in which the through-hole 22a is formed. The front wall 22 and the recovery section 75 are directly connected, and no piping or other components are provided that are exposed to the outside of the furnace body 20. The heating tube 10 is inserted through the through-hole 76a1 of the casing 76 at the front end of the furnace body 20, surrounded on all sides by the front wall 22. Therefore, the area around the heating tube 10 is covered by the furnace body 20 from the entrance (through-hole 21a) to the recovery section 75. As a result, the temperature of the material to be processed A does not easily decrease until it is recovered in the recovery section 75. Note that the casing 76 and the front wall 22 may be connected via an insulating material, similar to the components that make up the furnace body 20.

[0028] <Collection section 75> The recovery unit 75 includes a casing 76 and a hopper 77. The casing 76 is a roughly rectangular container that covers the position of the heating tube 10 where the discharge port 14a is provided. The rear portion 76a of the casing 76 is connected to the portion 22b of the front wall 22 of the furnace body 20 that protrudes forward. The casing 76 has through holes 76a1 and 76b1 that penetrate along the front-rear direction. The through holes 76a1 and 76b1 are roughly circular holes corresponding to the outer diameter of the heating tube 10. In the roughly rectangular casing 76, the through hole 76a1 is formed in the rear portion 76a, and the through hole 76a1 is formed in the front portion 76b. The rear portion 76a may be made of an insulating material. The heating tube 10 is inserted through the through holes 76a1 and 76b1. The discharge port 14a is formed in the portion of the heating tube 10 that is inserted through the through holes 76a1 and 76b1. Therefore, the transport space 10a is connected to the space 75a inside the casing 76 via the discharge port 14a. A sealing member (not shown) may be provided in the portion of the heating tube 10 that is inserted through the through holes 76a1 and 76b1 of the casing 76.

[0029] A hopper 77 is provided at the bottom of the casing 76. The hopper 77 protrudes downward from the bottom surface of the casing 76. The hopper 77 may narrow from the middle to the tip. The material to be processed A, discharged into the casing 76 from the outlet 14a of the heating tube 10, is discharged from the hopper 77 as appropriate and recovered. A lid 76c may be provided at the top of the casing 76, which can be opened and closed as appropriate during maintenance, etc.

[0030] <Drive mechanism 30> The drive mechanism 30 rotates the heating tube 10 relative to the furnace body 20. As shown in Figure 1, the drive mechanism 30 is located outside the furnace body 20. In this embodiment, the furnace body 20 is fixed. The drive mechanism 30 rotates only the heating tube 10 of the furnace body 20 and the heating tube 10. The drive mechanism 30 rotates the heating tube 10 using its cylindrical axis as the axis of rotation. The drive mechanism 30 is located outside the furnace body 20.

[0031] The drive mechanism 30 comprises a sprocket 31, a pair of tires 32, 33, and rollers 34, 35. The sprocket 31 is mounted in front of the tire 32, along its outer circumference. A chain (not shown) is wound around the sprocket 31. The chain is driven by a drive unit (not shown). The driving force of the drive unit is transmitted to the heating tube 10 via the chain and the sprocket 31. The pair of tires 32, 33 are annular and mounted along the outer circumference of the heating tube 10. Tire 32 is mounted on the first end 11 side of the heating tube 10. Tire 33 is mounted on the second end 12 side of the heating tube 10. The tires 32, 33 are rotatably supported by rollers 34, 35. The heating tube 10 rotates on the rollers 34, 35 via the tires 32, 33.

[0032] In this embodiment, the tire 33 is mounted downstream of the recovery unit 75.

[0033] In the embodiment shown in Figure 1, the rotation axis of the heating tube 10 is depicted as horizontal, but in reality, a predetermined angle of gradient may be set. The heating tube 10 is positioned such that the first end 11 is higher than the second end 12. As the heating tube 10 rotates, the material to be processed A is conveyed downwards. From this perspective, it is preferable that the heating tube 10 be installed with a gradient of, for example, an angle of about 0.5 to 1 degree. With a gradient of about 0.5 to 1 degree, powdery material is less likely to slide off, and the powdery material is easily conveyed at an appropriate speed in accordance with the rotation of the heating tube 10. Therefore, by adjusting the rotation speed of the heating tube 10, the time that the material remains inside the heating tube 10 can be adjusted. Note that the angle of the gradient is not limited to the above, and an appropriate angle, for example, an angle of about 0.3 to 5 degrees, may be selected. Note that the configuration of the heating tube 10 is not limited to the above-described form unless otherwise specified. For example, the inner surface of the heating tube 10 may be provided with spirally arranged blades so that the workpiece A is fed from the first end 11 to the second end 12 as the heating tube rotates. In this case, since the workpiece A is fed by the blades as the heating tube 10 rotates, the heating tube 10 does not need to have a slope.

[0034] Incidentally, in the rotary kiln 1 described above, the transport space 10a within the heating tube 10 is connected to the space 75a within the casing 76 via a plurality of outlets 14a. Not only the material to be processed A, but also the gas in the transport space 10a flows into the casing 76 from the plurality of outlets 14a. The gas in the transport space 10a can flow into the casing 76 through the outlets 14a that are not blocked by the material to be processed A. In the rotary kiln 1, the gas in the transport space 10a flows into the heating space 20a via the ventilation path 50.

[0035] <Ventilation path 50> The ventilation path 50 is a path connecting the transport space 10a and the heating space 20a. As shown in Figure 4, the front wall 22 of the furnace body 20 has another through-hole 22c formed in a different position from the through-hole 22a through which the heating tube 10 passes, and which passes along the transport direction. The through-hole 22c is formed in a portion 22b that protrudes forward, similar to the through-hole 22a through which the heating tube 10 passes. The through-hole 22c has a substantially circular opening and has a smaller opening area than the through-hole 22a. In this embodiment, three through-holes 22a are formed below the through-hole 22a through which the heating tube 10 passes. One of the through-holes 22c is formed directly below the central axis of the heating tube 10. The other two through-holes 22c are formed at positions flanking the through-hole formed directly below the central axis of the heating tube 10. The two through-holes 22C are formed below the heating tube 10 and above the through-hole formed directly below the central axis of the heating tube 10. In this embodiment, three through-holes 22c are formed below the heating tube 10, but the position and number of through-holes are not particularly limited.

[0036] Three through-holes 76a2 (see Figure 2) corresponding to the through-holes 22c are formed in the rear portion 76a of the casing 76. In this embodiment, the through-holes 76a2 are substantially the same shape as the through-holes 22c and are formed in substantially the same positions. Pipes corresponding to the inner diameter of each through-hole may be inserted through the through-holes 76a2 of the casing 76 and the through-holes 22c of the furnace body 20. Pipes that penetrate both through-holes 76a2 and 22c may be inserted through the through-holes 76a2 and 22c of the furnace body 20.

[0037] In this embodiment, the gas generated in the transport space 10a within the heating tube 10 flows through the outlet 14a into the space 75a within the casing 76. The gas generated in the transport space 10a within the heating tube 10 then flows through the through-hole 76a2 (see Figure 2) and the through-hole 22c into the heating space 20a within the furnace body 20. In this embodiment, the ventilation path 50 is formed by the through-hole 22c of the furnace body 20.

[0038] Incidentally, in a rotary kiln, the material being processed is heated inside the heating tube, which generates high-temperature gas from the material as a result of the heating process. Here, high-temperature gas is gas that is hotter than the temperature outside the furnace (for example, room temperature).

[0039] In the embodiment described above, as shown in Figure 1, the rotary kiln 1 comprises a cylindrical heating tube 10, a furnace body 20, a drive mechanism 30, a burner 40, and a ventilation path 50. The heating tube 10 has a transport space 10a formed inside through which the material to be processed A is transported. The furnace body 20 surrounds the heating tube 10. The furnace body 20 forms a heating space 20a between itself and the heating tube 10. The drive mechanism 30 rotates the heating tube 10 relative to the furnace body 20. The burner 40 heats the heating space 20a. The ventilation path 50 connects the transport space 10a and the heating space 20a. In such a rotary kiln 1, as the material to be processed A is heated, gas generated in the heating tube 10 flows into the heating space 20a in the furnace body 20. High-temperature gas is generated inside the heating tube 10. When high-temperature gas flows into the heating space 20a, the temperature of the heating space 20a rises more easily. This improves the heating efficiency of the heating tube 10 located in the heating space 20a, which is heated by the burner 40. As a result, the amount of fuel gas used can be reduced.

[0040] In the embodiment described above, the burner 40 is provided on the furnace body 20 (in this embodiment, the side wall 23). Therefore, the burner 40 can directly heat the heating space 20a inside the furnace body 20. Because the distance between the burner 40 and the heating tube 10 to be heated is short, the heating efficiency of the heating tube 10 can be good. For example, compared to a rotary kiln in which the burner is provided outside the furnace body and air heated by the burner outside the furnace body is introduced into the heating space inside the furnace body to heat the heating tube, the heating efficiency of the heating tube 10 can be good.

[0041] Furthermore, depending on the type of material being processed, carbonization gas containing hydrocarbon components may be generated from the material during the heating process within the heating tube 10. If carbonization gas is generated from material A within the heating tube 10, this generated carbonization gas is introduced into the heating space 20a within the furnace body 20. The carbonization gas introduced into the heating space 20a within the furnace body 20 is burned by the burner 40 in the heating space 20a. Therefore, the carbonization gas generated from the material being processed within the heating tube 10 can contribute to heating the heating space. As a result, the amount of fuel gas introduced into the burner 40 can be reduced. In addition, the carbonization gas generated within the heating tube 10 is introduced into the heating space 20a within the furnace body 20 and burned for treatment. Therefore, the burden of processing the gas discharged from the heating tube 10 is reduced.

[0042] In the embodiment described above, the through-hole 22c is located at the bottom of the furnace body 20 (front wall 22). Similarly, the burner 40 is located at the bottom of the furnace body 20 (side wall 23). Thus, among the ventilation paths 50, the through-hole 22c is located at a position corresponding to the burner 40. For example, the outlet of the through-hole 22c on the heating space 20a side may be located at a position that allows gas to be introduced into the combustion region by the burner 40. For example, the outlet of the through-hole 22c on the heating space 20a side may be located at a position that overlaps with the nozzle 40a of the burner 40. With this configuration, the carbonization gas that may be generated in the transport space 10a is more easily utilized for combustion in the burner 40. In addition, the carbonization gas that may be generated in the transport space 10a may rise in the heating space 20a after being introduced into the heating space 20a from the through-hole 22c. In this case, the outlet of the through-hole 22c on the heating space 20a side may be located at a lower position than the nozzle 40a of the burner 40. For example, the center height of the outlet of the through-hole 22c on the heating space 20a side is preferably lower than the center height of the nozzle 40a of the burner 40. This configuration makes it easier for the carbonization gas that may be generated in the conveying space 10a to be used for combustion in the burner 40. Note that the positional relationship between the outlet of the through-hole 22c on the heating space 20a side and the burner 40 is not limited to the above configuration. The through-hole 22c may be formed at a position further away from the burner 40 (for example, above the burner 40).

[0043] In the embodiment described above, the through-hole 22c is formed in the front wall 22 of the furnace body 20 from which the heating tube 10 protrudes. The ventilation path 50 is set to extend from the portion of the heating tube 10 that protrudes from the furnace body 20 to the end of the furnace body 20 (in this embodiment, the front wall 22). With this configuration, the ventilation path 50 from the portion of the heating tube 10 that protrudes to the furnace body 20 is shortened. This can suppress the temperature drop of the gas generated in the heating tube 10 before it flows into the heating space 20a. As a result, the heating efficiency of the heating tube 10 can be improved.

[0044] In the embodiment described above, the recovery unit 75 is connected to the furnace body 20. The gas generated in the transport space 10a within the heating tube 10 flows into the heating space 20a within the furnace body 20 through the through-holes 76a2 (see Figure 2) and 22c. For this reason, the ventilation path 50 is formed to go directly from the recovery unit 75 to the inside of the furnace body 20. With this configuration, the gas generated in the heating tube 10 is introduced into the furnace body 20 without passing through piping or the like outside the furnace body 20. This can suppress the temperature drop of the gas generated in the heating tube 10 before it flows into the heating space 20a. As a result, the heating efficiency of the heating tube 10 can be improved.

[0045] In the embodiment described above, an exhaust device 80 is connected to the exhaust duct 26a of the furnace body 20. In other words, the furnace body 20 is connected to an exhaust device 80 that draws in gas from the transport space 10a so that it is introduced into the heating space 20a through the ventilation path 50. This configuration makes it easier for gas in the transport space 10a to flow into the heating space 20a. As a result, the utilization efficiency of the gas in the transport space 10a can be improved.

[0046] In the rotary kiln 1 described above, the heating tube 10 protrudes from the furnace body 20 downstream in the transport direction in which the material to be processed A is transported. The drive mechanism 30 is equipped with a tire 33 attached to the portion of the heating tube 10 that protrudes from the furnace body 20. Upstream of the tire 33 in the portion of the heating tube 10 that protrudes from the furnace body 20, an outlet 14a for discharging the material to be processed A is provided. In the rotary kiln 1, a ventilation path 50 is provided that connects the transport space 10a and the heating space 20a. The gas generated in the heating tube 10 is introduced into the heating space 20a through the outlet 14a and the ventilation path 50. In the rotary kiln 1, the tire 33 is not interposed at the point where the outlet 14a and the ventilation path 50 are connected. Therefore, the temperature drop of the gas generated in the heating tube 10 before it flows into the heating space 20a can be suppressed. As a result, the heating efficiency of the heating tube 10 can be improved.

[0047] In the embodiment described above, the discharge port 14a is formed on the side surface 14 of the heating tube 10. Compared to a rotary kiln equipped with a heating tube having a discharge port formed at the downstream end, it is easier to shorten the distance between the furnace body 20 and the recovery section 75. As a result, the ventilation path 50 is shortened, and the temperature drop before the gas generated in the heating tube 10 flows into the heating space 20a can be suppressed.

[0048] Although a detailed explanation has been given above with specific embodiments, these are merely illustrative and do not limit the scope of the claims. Thus, the technologies described in the claims include various modifications and changes to the embodiments described above. Furthermore, this specification includes the following disclosures.

[0049] Section 1: A cylindrical heating tube with a transport space formed inside in which the object to be processed is transported, A furnace body that covers the periphery of the heating tube and forms a heating space between itself and the heating tube, A drive mechanism for rotating the heating tube relative to the furnace body, A burner for heating the aforementioned heating space, A ventilation path connecting the transport space and the heating space Equipped with, Rotary kiln.

[0050] Section 2: Downstream in the transport direction from which the workpiece is transported, the heating tube protrudes from the furnace body. The drive mechanism is equipped with a tire attached to the portion of the heating tube that protrudes from the furnace body. The rotary kiln according to item 1, wherein a discharge port for discharging the material to be processed is provided on the upstream side of the tire of the portion of the heating tube that protrudes from the furnace body.

[0051] Section 3: The rotary kiln described in item 2, wherein the discharge port is formed on the side surface of the heating tube.

[0052] Section 4: Downstream in the transport direction from which the workpiece is transported, the heating tube protrudes from the furnace body. The rotary kiln described in any one of items 1 to 3, wherein the ventilation path is set to extend from the portion of the heating tube protruding from the furnace body to the end of the furnace body.

[0053] Section 5: The portion of the heating tube that protrudes from the furnace body is provided with an outlet for discharging the material to be processed. The aforementioned discharge port is connected to a recovery unit that collects the material to be processed. The rotary kiln described in item 4, wherein the ventilation path is formed to lead directly from the recovery section to the interior of the furnace body.

[0054] Item 6: A rotary kiln according to any one of claims 1 to 5, wherein the burner is provided in the furnace body to form a combustion in the heating space.

[0055] Section 7: The rotary kiln described in item 6, wherein the ventilation path is positioned to allow gas to be introduced into the combustion region by the burner.

[0056] Section 8: A rotary kiln according to any one of claims 1 to 7, wherein the furnace body is connected to an exhaust device that draws in gas from the transport space so that it is introduced into the heating space through the ventilation path. [Explanation of Symbols]

[0057] 1. Rotary Kiln 10 heating tube 10a Conveying space 11 1st end 12 2nd end 14 Side surface 14a Outlet 20 Furnace body 20a heating space 21 Back wall 21a,22a,22c through hole 21b Sealing member 22 Front wall 22b Part 22b1 Lower part 22b2 Upper 23,24 side wall 25 Bottom wall 26 Ceiling and Wall 26a Exhaust duct 27 partitions 30 Drive mechanism 31 sprocket 32,33 tires 34,35 Laura 40 burners 40a nozzle 41 Fuel supply section 41a Fuel supply pipe 42 Combustion air supply unit 42a Combustion air supply pipe 50 Ventilation paths 70 Material supply section 71 Hoppa 72 Screw Feeder 73 Duct 75 Recovery Section 75a Space 76 Caging 76a posterior face 76a1, 76a2, 76b1 Through holes 76b Front 76c lid 77 ホッパ 80 exhaust device 81 Heat Exchanger A processed item

Claims

1. A cylindrical heating tube with a transport space formed inside in which the object to be processed is transported, A furnace body that covers the periphery of the heating tube and forms a heating space between itself and the heating tube, A drive mechanism for rotating the heating tube relative to the furnace body, A burner for heating the aforementioned heating space, A ventilation path connecting the transport space and the heating space Equipped with, Rotary kiln.

2. Downstream in the transport direction from which the workpiece is transported, the heating tube protrudes from the furnace body. The drive mechanism is equipped with a tire attached to the portion of the heating tube that protrudes from the furnace body. The rotary kiln according to claim 1, wherein a discharge port for discharging the material to be processed is provided on the upstream side of the tire of the portion of the heating tube that protrudes from the furnace body.

3. The rotary kiln according to claim 2, wherein the discharge port is formed on the side surface of the heating tube.

4. On the downstream side of the transport direction in which the workpiece is transported, the heating tube protrudes from the furnace body. The rotary kiln according to any one of claims 1 to 3, wherein the ventilation path is set to extend from the portion of the heating tube that protrudes from the furnace body to the end of the furnace body.

5. The portion of the heating tube that protrudes from the furnace body is provided with an outlet for discharging the material to be processed. The aforementioned discharge port is connected to a recovery unit that collects the material to be processed. The rotary kiln according to claim 4, wherein the ventilation path is formed to lead directly from the recovery section to the interior of the furnace body.

6. The rotary kiln according to any one of claims 1 to 3, wherein the burner is provided in the furnace body to form a combustion in the heating space.

7. The rotary kiln according to claim 6, wherein the ventilation path is provided in a position that allows gas to be introduced into the combustion region by the burner.

8. A rotary kiln according to any one of claims 1 to 3, wherein the furnace body is connected to an exhaust device that draws in gas from the transport space so that it is introduced into the heating space through the ventilation path.

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