rotary kiln

Abstract

High sealing performance can be easily achieved in rotary kilns. [Solution] The rotary kiln comprises a rotating cylindrical portion 11 that rotates around a central axis J1 and heats the material to be treated inside, a flange portion 61 provided at one axial end of the rotating cylindrical portion 11, a non-rotating member, an annular opposing portion 62 that faces that axial side of the flange portion 61, a cover portion 63 that covers the space from the opposing portion 62 to that axial side, annular first sealing member 641 and second sealing member 642 provided between the flange portion 61 and the opposing portion 62, and a gas filling portion 65 that fills a predetermined gas between the first sealing member 641 and the second sealing member 642 that are crushed between the flange portion 61 and the opposing portion 62 due to thermal expansion of the rotating cylindrical portion 11 in the axial direction, through a gas flow path 623 provided in the opposing portion 62 or the flange portion 61.

Description

[Technical Field]

[0001] The present invention relates to a rotary kiln. [Background technology]

[0002] Conventionally, rotary kilns are used to heat materials to be treated. In the device disclosed in Patent Document 1, a flange with an L-shaped cross section is provided on the peripheral wall at one end of the inner cylinder (rotating cylindrical portion) so as to protrude outward, and a seal plate is provided around the one end, surrounding a portion of the peripheral wall of the inner cylinder and the flange. A pair of mechanical seal members are provided where the flange and the seal plate face each other in the axial direction of the inner cylinder, and a gland packing or V-packing is provided where the flange and the seal plate face each other in the radial direction. An inert gas can be supplied to the space between the packing and the pair of seal members, achieving high sealing performance. The inert gas can be nitrogen, heated steam, carbon dioxide, or the like.

[0003] In the seal structure of the rotary kiln in Patent Document 2, an annular seal member is provided between a flange-shaped mounting plate attached to the outer periphery of the rotating drum (rotating cylindrical portion) and a hollow annular pressure plate extending from a fixed cover case via a bellows. The seal member has a groove-shaped steam enclosing portion around its entire periphery, facing the pressure plate. Steam is introduced into the steam enclosing portion from the outside. The steam liquefies on the sliding surface, forming a water film that acts as a lubricant between the seal member and the pressure plate.

[0004] The rotary cylindrical kiln of Patent Document 3 is provided with a rotary flange attached to its exterior, a sliding flange that contacts the rotary flange to allow rotation, and a cylindrical bellows that connects the sliding flange and fixed flange, and by filling the space surrounded by these with high-pressure superheated steam, the operational safety and furnace performance of the rotary cylindrical kiln are improved. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 5388567 [Patent Document 2] Patent No. 4439146 [Patent Document 3] Japanese Patent Publication No. 2022-124545 Summary of the Invention [Problem to be solved by the invention]

[0006] In the device disclosed in Patent Document 1, the outer peripheral surface of the flange that faces the packing radially is required to have high circularity. However, since the rotating tubular portion is typically large, it is difficult to form the outer peripheral surface with high circularity. Furthermore, the device also requires a pair of axially opposing sealing members (mechanical seals), resulting in a complex structure. Because mechanical seals are typically made of fluororesin, their use in the rotating tubular portion, which is subject to high temperatures, presents problems. The rotary kiln disclosed in Patent Document 2 requires a complex-shaped sealing member with a steam-sealing portion formed around the entire circumference. Furthermore, the structure disclosed in Patent Document 3 only allows contact between the rotating flange and the sliding flange, which may result in insufficient sealing performance. Therefore, a method for easily achieving high sealing performance in rotary kilns is needed.

[0007] The present invention has been made in consideration of the above-mentioned problems, and has as its object to easily achieve high sealing performance in a rotary kiln. [Means for solving the problem]

[0008] A first aspect of the present invention is a rotary kiln for heating a workpiece, the rotary kiln comprising: a cylindrical rotating tubular portion having a central axis and openings at both ends in an axial direction parallel to the central axis, the rotating tubular portion rotating around the central axis while heating the workpiece; a flange portion provided at one end of the rotating tubular portion in the axial direction and extending radially; a non-rotating annular opposing portion facing the one side in the axial direction relative to the flange portion; a cover portion covering the space from the opposing portion to the one side in the axial direction; a first annular sealing member provided between the flange portion and the opposing portion; a second annular sealing member provided inside the first sealing member and between the flange portion and the opposing portion; and a gas filling portion that fills a predetermined gas between the first sealing member and the second sealing member, which are crushed between the flange portion and the opposing portion due to thermal expansion of the rotating tubular portion in the axial direction, through a gas flow path provided in the opposing portion or the flange portion.

[0009] A second aspect of the present invention is the rotary kiln of the first aspect, wherein each of the first seal member and the second seal member is a braided packing.

[0010] A third aspect of the present invention is a rotary kiln according to the first aspect (which may be either the first or second aspect), further comprising a regulating portion facing the flange portion on the other side in the axial direction, and a connecting portion connecting the opposing portion and the regulating portion radially outside the flange portion, so that the flange portion and the regulating portion come into contact when the rotating cylindrical portion contracts in the axial direction.

[0011] A fourth aspect of the present invention is the rotary kiln of the third aspect, wherein the regulating portion has a roller that is rotatable around an axis extending in the radial direction.

[0012] A fifth aspect of the present invention is a rotary kiln according to the first aspect (which may be any one of the first to fourth aspects), further comprising an annular third seal member disposed inside the second seal member between the flange portion and the opposing portion.

[0013] A sixth aspect of the present invention is a rotary kiln according to any one of the first to fifth aspects, wherein the cover portion comprises a fixed portion arranged on one side of the opposing portion in the axial direction, and an expandable tube that is cylindrical and centered on the central axis and connects the opposing portion and the fixed portion, the flange portion extends radially outward from the edge of the opening at the one end of the rotating cylindrical portion, and the specified gas includes water vapor.

[0014] A seventh aspect of the present invention is a rotary kiln according to any one of the first to fifth aspects (which may also be any one of the first to sixth aspects), wherein the cover part comprises a fixed part arranged on one side of the opposing part in the axial direction, and an expandable tube that is cylindrical and centered on the central axis and connects the opposing part and the fixed part, wherein a drain port is provided in any part of the cover part for discharging liquid in the expandable tube to the outside, and the specified gas includes water vapor. [Effects of the Invention]

[0015] According to the present invention, high sealing performance can be easily achieved. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a diagram showing the configuration of a gasification apparatus. [Figure 2] FIG. 2 is a diagram showing a first blocking section and its vicinity. [Figure 3] FIG. 10 is a plan view of the opposing portion of the first blocking part. [Figure 4] FIG. 10 is a diagram showing a second blocking section and its vicinity. [Figure 5] FIG. 10 is a plan view of the opposing portion of the second blocking portion. DETAILED DESCRIPTION OF THE INVENTION

[0017] FIG. 1 is a diagram showing the configuration of a gasification apparatus 1 according to one embodiment of the present invention. FIG. 1 shows a cross section taken along a plane including a central axis J1 of a rotary cylindrical portion 11, which will be described later. The gasification apparatus 1 is an externally heated rotary kiln (indirectly heated rotary kiln) that gasifies a material to be treated, which is general waste, by heating it to produce a reformed gas, which is a combustible gas. The reformed gas is used, for example, to generate electricity in a gas engine or the like. The material to be treated is not limited to general waste, and may be industrial waste, sewage sludge, woody biomass, or the like.

[0018] The gasification apparatus 1 comprises a rotating cylindrical section 11, a heating section 12, a material supply section 13, a mixed gas introduction section 14, an agitation section 15, a separation section 16, a rotation section 18, and a control section (not shown). The control section is, for example, a computer equipped with a CPU or the like, and is responsible for overall control of the gasification apparatus 1. The rotating cylindrical section 11 is cylindrical with a central axis J1 as its center, and is formed of, for example, a metal or an alloy (the same applies to other components provided inside the rotating cylindrical section 11). The central axis J1 is horizontal or approximately horizontal. Depending on the design of the gasification apparatus 1, the central axis J1 may be inclined relative to the horizontal direction.

[0019] In the example of FIG. 1 , the rotating cylindrical portion 11 includes a cylindrical main body 101 and a cylindrical tip portion 102. Both the cylindrical main body 101 and the cylindrical tip portion 102 are cylindrical and centered on a central axis J1, with the cylindrical tip portion 102 provided at one end of the cylindrical main body 101. More specifically, a main body flange 116 is fixed to one end face of the cylindrical main body 101. The main body flange 116 is an annular plate member centered on the central axis J1. The inner diameter of the main body flange 116 is smaller than the diameter of the cylindrical main body 101, and the outer diameter of the main body flange 116 is larger than the diameter of the cylindrical main body 101. The cylindrical tip portion 102 protrudes cylindrically from the inner peripheral edge of the main body flange 116. The portion of the main body flange 116 between the cylindrical main body 101 and the cylindrical tip portion 102 is part of the rotating cylindrical portion 11. This portion may be a member independent of the main body flange 116. In the rotating cylindrical portion 11, the end opening on one side in a direction parallel to the central axis J1 (hereinafter referred to as the "axial direction") is the opening of the cylindrical tip portion 102, and the end opening on the other side is the opening of the cylindrical main body 101. The end opening on one side is the supply port 111, and the end opening on the other side is the discharge port 112.

[0020] As will be described later, inside the rotating cylindrical part 11, the material to be processed moves from the supply port 111 toward the discharge port 112. A supply-side annular part 114 is provided at the end of the cylindrical main body 101 on the supply port 111 side. The supply-side annular part 114 is an annular member that protrudes from the inner circumferential surface of the cylindrical main body 101 over the entire circumferential circumference centered on the central axis J1. A discharge-side annular part 115 is provided at the end of the cylindrical main body 101 on the discharge port 112 side. The discharge-side annular part 115 is an annular member that protrudes from the inner circumferential surface of the cylindrical main body 101 over the entire circumferential circumference.

[0021] The rotating unit 18 rotates the rotating cylindrical portion 11 around the central axis J1. As described above, a main body flange 116 is provided at the end of the cylindrical main body 101 on the supply port 111 side. A pair of rollers 181 of the rotating unit 18 is provided below the main body flange 116. The pair of rollers 181 are spaced apart in a direction perpendicular to the plane of FIG. 1 . The main body flange 116 is rotatably supported by the pair of rollers 181. In addition, a main body flange 117 is provided on the outer circumferential surface of the cylindrical main body 101 near the end on the discharge port 112 side. Like the main body flange 116, the main body flange 117 is also an annular plate member centered on the central axis J1 and is rotatably supported by a pair of rollers 182. In the rotating unit 18, a rotation mechanism 183 having a motor and a reducer is connected to the roller 181. When the rotation mechanism 183 rotates the roller 181, the rotating cylindrical portion 11 continuously rotates around the central axis J1. The rotation speed of the rotary cylindrical part 11 is, for example, constant. The structure for rotating the rotary cylindrical part 11 may be changed as appropriate.

[0022] The heating unit 12 has an outer cylindrical portion 121. The outer cylindrical portion 121 is cylindrical and centered on the central axis J1. The outer cylindrical portion 121 is made of, for example, a metal or an alloy. The outer cylindrical portion 121 is a fixed body that does not rotate. The outer cylindrical portion 121 surrounds the periphery of the cylindrical main body 101 between the two main body flanges 116 and 117, forming a cylindrical space 120 between the outer cylindrical portion 121 and the outer peripheral surface of the cylindrical main body 101. Annular walls 21 and 22 are provided at both axial ends of the outer cylindrical portion 121. Each annular wall 21 and 22 is an annular member centered on the central axis J1 and protrudes from the outer cylindrical portion 121 toward the cylindrical main body 101. The end surfaces of the annular walls 21 and 22 facing the cylindrical main body 101 contact the outer peripheral surface of the cylindrical main body 101 via, for example, a sliding member. This forms a seal between the annular walls 21 and 22 and the cylindrical main body 101.

[0023] An outlet 23 and an inlet 24 are formed in the outer cylindrical portion 121. The outlet 23 is provided near the annular wall 21 on the supply port 111 side, and is connected to the cylindrical space 120. The inlet 24 is provided near the annular wall 22 on the discharge port 112 side, and is connected to the cylindrical space 120. High-temperature gas is supplied to the inlet 24 from the outside. The temperature of the high-temperature gas at the inlet 24 is, for example, 900 to 1100°C. The high-temperature gas flows through the cylindrical space 120 and is discharged from the outlet 23. The high-temperature gas flowing through the cylindrical space 120 heats the outer peripheral surface of the rotating cylindrical portion 11 (the cylindrical main body 101 thereof).

[0024] The material supply unit 13 includes a hopper 131 and a screw feeder 132. The material is stored in the hopper 131. The screw feeder 132 includes a casing 30, a rotation mechanism 31, and a screw 32. The casing 30 is cylindrical and centered on a central axis J1, and extends from the bottom of the hopper 131 to the inside of the cylindrical main body 101 via the supply port 111 of the rotating cylindrical portion 11. In the example of FIG. 1, minute gaps are provided around the entire circumference between the outer circumferential surface of the casing 30 and the inner circumferential surfaces of the cylindrical tip portion 102 and the supply-side annular portion 114 (see FIG. 2, described later).

[0025] The screw 32 is disposed within the casing 30 and extends from the bottom of the hopper 131 to the inside of the cylindrical body 101. The rotation mechanism 31 has a motor and a reducer, and rotates the screw 32. As a result, the material to be treated in the hopper 131 is supplied to the inside of the rotating cylindrical portion 11 via the casing 30. The supply of the material to be treated by the material supply portion 13 into the rotating cylindrical portion 11 may be continuous or intermittent. The screw shaft 321 of the screw 32 is hollow. An introduction pipe 141, which will be described later, is disposed in the hollow portion of the screw shaft 321. The introduction pipe 141 extends along the central axis J1.

[0026] The agitator 15 is provided inside the rotary cylindrical part 11. The agitator 15 is fixed to the rotary cylindrical part 11. That is, when the rotary cylindrical part 11 rotates around the central axis J1, the agitator 15 also rotates. The agitator 15 has a pyrolysis part 151 and a reforming part 152. The pyrolysis part 151 is provided on the supply port 111 side, and the reforming part 152 is provided on the discharge port 112 side. The pyrolysis part 151 includes a partition plate 41 and a guide part 42. The partition plate 41 is a plate member parallel to the central axis J1 and is disposed on the central axis J1. Both ends of the partition plate 41 in a direction perpendicular to the central axis J1 are fixed to the inner circumferential surface of the rotary cylindrical part 11. When viewed along the central axis J1, the internal space of the rotary cylindrical part 11 is divided into two equal parts by the partition plate 41. The partition plate 41 has a relatively large thickness (thickness between the main surfaces), and is provided with a through hole 411 on the central axis J1. The introduction pipe 141 is inserted into the through hole 411.

[0027] The guide portion 42 includes a plurality of linear protrusions 421. Some of the linear protrusions 421 protrude from one main surface of the partition plate 41, and the remaining linear protrusions 421 protrude from the other main surface of the partition plate 41. The linear protrusions 421 provided on each main surface of the partition plate 41 are parallel to each other. In the example of FIG. 1, all of the linear protrusions 421 on each main surface of the partition plate 41 extend in the same direction inclined with respect to the axial direction. In FIG. 1, the linear protrusions 421 arranged on the near side when the partition plate 41 is rotated 180 degrees about the central axis J1 are indicated by two-dot chain lines. The inclination direction of the linear protrusions 421 indicated by the two-dot chain lines is opposite to the inclination direction of the linear protrusions 421 indicated by the solid lines (the direction inverted with respect to the central axis J1). In other words, the plurality of linear protrusions 421 are arranged symmetrically with respect to the partition plate 41. The partition plate 41 rotates about the central axis J1 in accordance with the rotation of the rotary cylindrical part 11. Accordingly, the plurality of linear protrusions 421 on one main surface of the partition plate 41 move the material to the supply port 111 side, and the plurality of linear protrusions 421 on the other main surface move the material to the reforming part 152 side.

[0028] As described above, the rotating cylindrical section 11 is heated by the high-temperature gas flowing through the cylindrical space 120. In the pyrolysis section 151, the material to be treated is heated, for example, to a temperature of 400°C or higher (preferably 700°C or lower), causing pyrolysis, producing pyrolysis gas and residues such as char, tar, and incombustible materials. The outlet 112 is decompressed by an induction fan (not shown), and the pyrolysis gas flows toward the outlet 112. The pyrolysis gas also contains residue particles (char particles, incombustible soot, etc.). The material to be treated that is not contained in the pyrolysis gas remains in the pyrolysis section 151. When the material to be treated is supplied from the material supply section 13, some of the material remaining in the pyrolysis section 151 is pushed toward the reforming section 152 (the outlet 112 side). An intermediate restriction section 113 may be provided between the pyrolysis section 151 and the reforming section 152 inside the rotating cylindrical section 11. The intermediate restriction section 113 is an annular member and functions as a weir that restricts the movement of the material to be treated from the pyrolysis section 151 to the reforming section 152.

[0029] In the example shown in FIG. 1 , the reforming section 152 has substantially the same structure as the pyrolysis section 151 and includes a partition plate 41 and a guide section 42. The partition plate 41 of the reforming section 152 does not have the through-hole 411. In the reforming section 152, the partition plate 41 also rotates about the central axis J1 in conjunction with the rotation of the rotary cylindrical section 11. Accordingly, the plurality of linear protrusions 421 on one main surface of the partition plate 41 move the material toward the pyrolysis section 151, and the plurality of linear protrusions 421 on the other main surface move the material toward the discharge port 112. In practice, the material is sequentially supplied from the pyrolysis section 151 to the reforming section 152, and excess material passes over the discharge-side annular section 115 and is discharged from the discharge port 112 as the final residue. The reforming section 152 may have a different structure from the pyrolysis section 151.

[0030] The mixed gas introduction section 14 includes an introduction pipe 141 and a mixed gas supply section 142. As described above, the introduction pipe 141 passes through the hollow section of the screw shaft 321 and the through-hole 411 of the partition plate 41. The mixed gas supply section 142 is connected to one end of the introduction pipe 141 outside the rotating cylindrical section 11. The other end of the introduction pipe 141 is disposed near the reforming section 152 inside the rotating cylindrical section 11. An ejection port 143 is provided at the tip (other end) of the introduction pipe 141. For example, the ejection port 143 is disposed between the pyrolysis section 151 and the reforming section 152 in the axial direction.

[0031] The mixed gas supply unit 142 supplies a mixed gas containing an oxygen-containing gas and water vapor to the inlet pipe 141, and the mixed gas is ejected from the ejection port 143. The oxygen-containing gas is, for example, air or oxygen-enriched air, and in this embodiment, it is preheated high-temperature air. The temperature of the mixed gas is, for example, 200 to 300°C. In the reforming unit 152, the pyrolysis gas flowing toward the outlet 112 is mixed (agitated) with the mixed gas and the object to be treated. As a result, flammable gases and tar vapor contained in the pyrolysis gas are partially combusted (i.e., a portion of the pyrolysis gas is combusted). The object to be treated also partially combusts. Due to the partial combustion of the pyrolysis gas and the object to be treated, the pyrolysis gas flowing through the reforming unit 152 and the object to be treated in the reforming unit 152 reach high temperatures. The mixed gas also contains water vapor. As a result, hydrocarbon gases and the like contained in the pyrolysis gas are converted into gases such as hydrogen (H) and carbon monoxide (CO) through a steam reforming reaction (i.e., steam reformed). Tar and powdered char contained in the pyrolysis gas, as well as the char in the reforming section 152, are also steam reformed.

[0032] As described above, in the reforming section 152 to which the pyrolysis gas and the material to be treated are sent from the pyrolysis section 151, the pyrolysis gas is partially burned and the char contained in the pyrolysis gas and the material to be treated is steam reformed to produce a reformed gas. The temperature of the pyrolysis gas and the char in the reforming section 152 is, for example, 700°C or higher, preferably 800°C or higher, and more preferably 900°C or higher. The temperature is, for example, 1100°C or lower. The reformed gas is discharged from the rotary tubular section 11 through the outlet 112.

[0033] The separation section 16 is connected to the discharge port 112. The separation section 16 forms a path extending in the vertical direction. The reformed gas is discharged along the path going upward, purified, and then recovered. The purified gas may be supplied to a gas engine-type generator or the like. The residue discharged from the discharge port 112 falls along the path going downward and is recovered. The recovered char may be combusted, and high-temperature gas generated by the combustion heat may be used to heat the rotary tubular section 11. As described above, in the gasification apparatus 1, the material to be treated (and the residue) moves from the hopper 131 of the material to be treated supply section 13 through the rotary tubular section 11 to the separation section 16. Therefore, in the following description, the hopper 131 side in the axial direction is referred to as the axial upstream side, and the separation section 16 side is referred to as the axial downstream side.

[0034] The gasification apparatus 1 further includes a first closing section 6a and a second closing section 6b. The first closing section 6a is provided axially upstream of the cylindrical tip section 102 and closes the space axially upstream from the cylindrical tip section 102 around the casing 30 of the screw feeder 132. The second closing section 6b is provided axially downstream of the main body flange 117 on the discharge port 112 side and closes the space axially downstream from the main body flange 117 together with the separation section 16, except for the path of the separation section 16.

[0035] FIG. 2 is a cross-sectional view of the first closing portion 6a and its vicinity, taken along a plane including the central axis J1. The first closing portion 6a includes a flange portion 61, a facing portion 62, a cover portion 63, a seal portion 64, a gas filling portion 65, and a plurality of regulating units 66. The flange portion 61 is an annular plate member centered on the central axis J1 and is formed of, for example, a metal or alloy (the same applies to the facing portion 62, the cover portion 63, and the regulating units 66). The flange portion 61 is provided at the tip of the cylindrical tip portion 102 on the upstream side in the axial direction (the right side in FIG. 2). Specifically, the inner diameter of the flange portion 61 is approximately the same as the diameter of the cylindrical tip portion 102, and the flange portion 61 extends radially outward from the edge of the axially upstream end opening of the cylindrical tip portion 102 (i.e., the supply port 111). The outer diameter of the flange portion 61 is smaller than the outer diameter of the main flange 116.

[0036] The facing portion 62 is an annular plate member centered on the central axis J1, and faces the flange portion 61 on the upstream side in the axial direction. As will be described later, the facing portion 62 is supported by the cover portion 63 in a state in which it is movable in the axial direction. In the example of FIG. 2, the diameter of the inner circumference of the facing portion 62 is approximately the same as the diameter of the inner circumference of the flange portion 61. Gaps are provided around the entire circumference between the inner circumference of the flange portion 61 and the inner circumference of the facing portion 62 and the casing 30 of the screw feeder 132. The diameter of the outer circumference of the facing portion 62 is larger than the diameter of the outer circumference of the flange portion 61.

[0037] The cover part 63 includes a fixed part 631 and an expandable tube 632. The fixed part 631 is an annular plate member centered on the central axis J1, and extends radially outward from the outer circumferential surface of the casing 30. The fixed part 631 is disposed axially upstream of the facing part 62. The expandable tube 632 is cylindrical and centered on the central axis J1, and surrounds the periphery of the casing 30. The expandable tube 632 connects the facing part 62 and the fixed part 631. An example of the expandable tube 632 is a bellows piping, which is expandable and contractible in the axial direction. With this structure, the cover part 63 covers the space axially upstream of the facing part 62 around the casing 30.

[0038] An expandable portion 636 may be provided between the facing portion 62 and the fixed portion 631 on the radially outer side of the expandable tube 632. The expandable portion 636 is expandable and contractible along the axial direction. The expandable tube 632 and the expandable portion 636 allow the facing portion 62 to move in the axial direction, while fixing the position of the facing portion 62 in the circumferential direction relative to the fixed portion 631. Depending on the design of the gasification apparatus 1, a pressing mechanism such as an air cylinder may be provided as the expandable portion 636, and the facing portion 62 may be biased toward the flange portion 61. Furthermore, a plurality of expandable portions 636 may be arranged in the circumferential direction.

[0039] A drain port 633 is provided in a portion of the fixed part 631 below the casing 30. More specifically, the drain port 633 is formed in this portion of the fixed part 631 at a position communicating with the interior of the expandable tube 632, preferably near the lowest part of the expandable tube 632. One end of a discharge pipe 634 is connected to the drain port 633, and the other end of the discharge pipe 634 is connected to a discharged liquid collection part 635. As will be described later, when liquid accumulates inside the expandable tube 632, the liquid can be discharged to the discharged liquid collection part 635 via the drain port 633 and the discharge pipe 634 by opening a valve (for example, a ball valve) provided on the discharge pipe 634.

[0040] FIG. 3 is a plan view of the opposing portion 62, showing a surface 620 (hereinafter referred to as the "opposing surface 620") that faces the flange portion 61. In FIG. 3, a first seal member 641 and a second seal member 642, which will be described later, are indicated by parallel diagonal lines (similar to FIG. 5, which will be described later). As shown in FIGS. 2 and 3, the seal portion 64 includes a first seal member 641 and a second seal member 642. The first seal member 641 and the second seal member 642 are both annular and centered on the central axis J1, and the diameter of the first seal member 641 is larger than the diameter of the second seal member 642. The first seal member 641 and the second seal member 642 are provided between the flange portion 61 and the opposing portion 62.

[0041] More specifically, two annular grooves 621, 622 are formed on the opposing surface 620 of the opposing part 62, with the center being the central axis J1. The diameter of one annular groove 621 is approximately the same as the diameter of the first seal member 641, and the diameter of the other annular groove 622 is approximately the same as the diameter of the second seal member 642. The first seal member 641 and the second seal member 642 are fitted into the annular grooves 621, 622, respectively. In this manner, the second seal member 642 is provided inside the first seal member 641 on the opposing surface 620. One example of the first seal member 641 and the second seal member 642 is a braided packing (also called a gland packing) made by braiding together thread-like packing materials.

[0042] When the gasification apparatus 1 processes the material to be processed, as described above, the rotating cylindrical portion 11 rotates about the central axis J1, and the first seal member 641 and the second seal member 642 on the opposing portion 62, which is a non-rotating member, slide against the flange portion 61, which is a rotating member. In this manner, the seal member 64 is a sliding portion that slides against the flange portion 61. Furthermore, the rotating cylindrical portion 11 (the cylindrical main body 101 thereof) is heated by the heating portion 12, and the rotating cylindrical portion 11 thermally expands in the axial direction. As a result, the flange portion 61 is urged (pressed) toward the opposing portion 62, and the first seal member 641 and the second seal member 642 are crushed between the flange portion 61 and the opposing portion 62. In other words, the gaps between the respective seal members 641, 642 and the flange portion 61 are sealed, and the gaps between the seal members 641, 642 and the opposing portion 62 are also sealed.

[0043] 3, a plurality of gas outlets 624 are provided between the two annular grooves 621, 622 on the opposing surface 620 of the opposing part 62. For example, the plurality of gas outlets 624 are arranged at equal angular intervals in the circumferential direction. Each gas outlet 624 is an opening at one end of a gas flow path 623 that penetrates the inside of the opposing part 62. An opening at the other end of the gas flow path 623 is formed on a surface of the opposing part 62 other than the opposing surface 620. In the example of FIG. 2, the opening at the other end is provided on the outer peripheral surface of the opposing part 62, and a gas pipe 652, which will be described later, is connected to the opening.

[0044] The gas filling section 65 includes a gas supply source 651 and a gas pipe 652. The gas pipe 652 connects the gas supply source 651 to each gas flow path 623. When the gas supply source 651 supplies a predetermined gas (hereinafter referred to as "auxiliary gas") to the gas pipe 652, the auxiliary gas is ejected from the plurality of gas ejection ports 624 on the opposing surface 620 of the opposing part 62. The pressure of the auxiliary gas is higher than the pressure inside the rotating cylindrical part 11 and higher than the external atmospheric pressure. As described above, in the first closing part 6a, the auxiliary gas is filled in the space between the first seal member 641 and the second seal member 642 that are crushed between the flange part 61 and the opposing part 62.

[0045] Filling the auxiliary gas prevents gas in the space radially inside the second seal member 642 (hereinafter referred to as the "sealed portion inner space"), such as gas containing pyrolysis gas, from leaking out to the space outside the first seal member 641 (i.e., to the outside). It also prevents external air from flowing into the sealed portion inner space. As described above, the sealing performance of the seal portion 64 is improved. The auxiliary gas is, for example, superheated steam, an inert gas such as carbon dioxide, or the like, and is preferably the same type as the gas used or generated inside the cylindrical main body 101. In this embodiment, the auxiliary gas is superheated steam. The superheated steam is generated, for example, by using the heat of high-temperature gas discharged from the outlet 23 of the outer cylindrical portion 121.

[0046] In the gasification apparatus 1, for example, while the material to be treated is being treated, auxiliary gas is constantly supplied from the gas supply source 651 to the gas flow path 623, and the auxiliary gas is continuously ejected from the gas ejection port 624. The supply of auxiliary gas from the gas supply source 651 may be intermittent. A portion of the auxiliary gas filling the gap between the first seal member 641 and the second seal member 642 passes through the gap between the second seal member 642 and the flange portion 61 (and the opposing portion 62) and enters the seal portion inner space. As described above, the interior of the rotating cylindrical portion 11 is decompressed, and most of the auxiliary gas that has entered the seal portion inner space passes through the gap between the outer peripheral surface of the casing 30 and the inner peripheral surface of the cylindrical tip portion 102 and the inner peripheral surface of the supply-side annular portion 114 and flows into the cylindrical main body 101. When the auxiliary gas is superheated steam, it is used for the steam reforming described above together with the steam contained in the mixed gas.

[0047] A portion of the auxiliary gas that has entered the space inside the seal portion may move into the elastic pipe 632. If the auxiliary gas is superheated steam, the auxiliary gas may be cooled by outside air inside the elastic pipe 632, causing condensation. The condensed water accumulates inside the elastic pipe 632. In this case, when the gasification apparatus 1 is stopped, for example, by opening a valve provided on the discharge pipe 634, it is possible to discharge the water inside the elastic pipe 632 to the waste liquid recovery unit 635. Note that a portion of the auxiliary gas filled between the first seal member 641 and the second seal member 642 may pass through the gap between the first seal member 641 and the flange portion 61 and be discharged to the outside.

[0048] The plurality of regulating units 66 are arranged at equal angular intervals in the circumferential direction and attached to the opposing portion 62. Each regulating unit 66 includes a regulating portion 67 and a connecting portion 68. The regulating portion 67 faces the flange portion 61 on the axial downstream side (left side in FIG. 2). The regulating portion 67 and the flange portion 61 are slightly separated from each other in the axial direction. They may also be in contact with each other. In the regulating unit 66 of FIG. 2, the regulating portion 67 has a roller 671 that can rotate about an axis extending in the radial direction. The surface of the roller 671 faces the surface of the flange portion 61 on the axial downstream side. The connecting portion 68 connects the opposing portion 62 and the regulating portion 67 on the radial outside of the flange portion 61. In the example of FIG. 2, the connecting portion 68 extends from the outer periphery of the opposing portion 62 to the axial downstream side, and the shaft of the roller 671 is supported by the tip of the connecting portion 68.

[0049] When the gasifier 1 stops processing the material to be processed, the heating of the rotating cylindrical part 11 by the heating unit 12 is also stopped. This causes the rotating cylindrical part 11 to contract in the axial direction, and the flange part 61 moves axially downstream. At this time, the flange part 61 and the restricting part 67 come into contact with each other, preventing the flange part 61 and the opposing part 62 from moving excessively apart. In practice, as the telescopic tube 632 extends, the opposing part 62 also moves slightly axially downstream together with the flange part 61. As described above, when the gasifier 1 processes the material to be processed, thermal expansion of the rotating cylindrical part 11 causes the flange part 61 to move axially upstream, and the restricting part 67 and the flange part 61 move slightly apart in the axial direction. However, because the gap between the restricting part 67 and the flange part 61 is small, they may come into contact with each other. Even in this case, the roller 671 rolling on the surface of the rotating flange part 61 prevents damage to the flange part 61 and the restricting part 67. Depending on the design of the restriction unit 66, the restriction portion 67 may slide on the surface of the flange portion 61.

[0050] FIG. 4 is a diagram showing the second closing portion 6b and its vicinity, showing a cross section taken along a plane including the central axis J1. Unless otherwise noted, the components of the second closing portion 6b are the same as those of the first closing portion 6a in FIG. 2, inverted with respect to a plane perpendicular to the central axis J1. The second closing portion 6b includes a flange portion 61, a facing portion 62, a cover portion 63, a seal portion 64, a gas filling portion 65, and a plurality of restriction units 66. The flange portion 61 is an annular plate member centered on the central axis J1 and is disposed on the axial downstream side (left side in FIG. 4) of the main body flange 117. Specifically, a cylindrical support portion 611 protruding axially downstream is provided on the main body flange 117 near the cylindrical main body 101, and the flange portion 61 is provided at the tip of the cylindrical support portion 611. The flange portion 61 extends radially outward from the tip of the cylindrical support portion 611. The diameter of the outer periphery of the flange portion 61 is smaller than the diameter of the outer periphery of the main body flange 116. The opposing portion 62 faces the flange portion 61 on the downstream side in the axial direction.

[0051] The cover part 63 includes a fixed part 631 and an expandable tube 632. The fixed part 631 is an annular plate member centered on the central axis J1, and extends radially outward from the outer circumferential surface of a cylindrical part 161 that surrounds the cylindrical main body 101 in the separation part 16. The fixed part 631 is disposed axially downstream of the facing part 62. The expandable tube 632 is cylindrical and centered on the central axis J1, and surrounds the cylindrical main body 101. The expandable tube 632 connects the facing part 62 and the fixed part 631. With this structure, the cover part 63, together with the separation part 16, covers the space axially downstream of the facing part 62 around the cylindrical main body 101. A expandable part 636 may be provided radially outside the expandable tube 632, between the facing part 62 and the fixed part 631. A drain port 633 is provided in a portion of the fixing part 631 below the cylindrical main body 101. One end of a drain pipe 634 is connected to the drain port 633, and the other end of the drain pipe 634 is connected to a drained liquid recovery part 635.

[0052] FIG. 5 is a plan view of the facing portion 62 of the second closing portion 6b, showing the facing surface 620 facing the flange portion 61. As shown in FIGS. 4 and 5, the seal portion 64 of the second closing portion 6b further includes a third seal member 643 in addition to a first seal member 641 and a second seal member 642. The first seal member 641, the second seal member 642, and the third seal member 643 are all annular and centered on the central axis J1. The diameter of the first seal member 641 is larger than the diameter of the second seal member 642, and the diameter of the second seal member 642 is larger than the diameter of the third seal member 643. The first seal member 641, the second seal member 642, and the third seal member 643 are provided between the flange portion 61 and the facing portion 62.

[0053] Specifically, three annular grooves 621-623 are formed on the opposing surface 620 of the opposing portion 62, with the center being the central axis J1. The diameters of the three annular grooves 621-623 are approximately the same as the diameters of the first seal member 641, the second seal member 642, and the third seal member 643, respectively. The first seal member 641, the second seal member 642, and the third seal member 643 are fitted into the annular grooves 621-623. When the gasifier 1 processes the material to be treated, the first seal member 641, the second seal member 642, and the third seal member 643 on the opposing portion 62, which is a non-rotating member, slide against the flange portion 61, which is a rotating member. Furthermore, due to thermal expansion of the rotary cylindrical portion 11 in the axial direction, the first seal member 641, the second seal member 642, and the third seal member 643 are crushed between the flange portion 61 and the opposing portion 62. In other words, the gaps between the respective seal members 641 to 643 and the flange portion 61 are sealed, and the gaps between the respective seal members 641 to 643 and the opposing portion 62 are also sealed.

[0054] 5, a plurality of gas outlets 624 are provided between the two annular grooves 621, 622 on the opposing surface 620 of the opposing part 62. Each gas outlet 624 is an opening at one end of a gas flow path 623 that penetrates the interior of the opposing part 62. The gas filling part 65 includes a gas supply source 651 and a gas pipe 652. The gas pipe 652 connects the gas supply source 651 to each gas flow path 623. The gas supply source 651 supplies auxiliary gas to the gas pipe 652, whereby the auxiliary gas is ejected from the plurality of gas outlets 624 on the opposing surface 620 of the opposing part 62. Filling the space between the first seal member 641 and the second seal member 642 with auxiliary gas more reliably suppresses fluid movement between a seal-part inner space, which is a space radially inward of the third seal member 643, and a space (outside) outer than the first seal member 641.

[0055] A portion of the auxiliary gas filling the gap between the first seal member 641 and the second seal member 642 passes through the gap between the second seal member 642 and the flange portion 61 (and the opposing portion 62) and the gap between the third seal member 643 and the flange portion 61, and enters the space inside the seal member. As described above, the outlet 112 is decompressed, and most of the auxiliary gas that has entered the space inside the seal member passes through the gap between the outer circumferential surface of the cylindrical main body 101 and the cylindrical portion 161 of the telescopic pipe 632 and the separation unit 16, and flows into the separation unit 16. When the auxiliary gas is superheated steam, some of the auxiliary gas may be cooled by outside air inside the telescopic pipe 632, causing condensation. The condensed water accumulates inside the telescopic pipe 632. In this case, when the gasification apparatus 1 is stopped, the water inside the telescopic pipe 632 can be discharged to the waste liquid recovery unit 635 by opening the valve provided on the discharge pipe 634.

[0056] The plurality of regulating units 66 are arranged at equal angular intervals in the circumferential direction and attached to the opposing portion 62. Each regulating unit 66 includes a regulating portion 67 and a connecting portion 68. The regulating portion 67 faces the flange portion 61 on the upstream side in the axial direction. In the regulating unit 66 of FIG. 4, the regulating portion 67 has a roller 671 that is rotatable about an axis extending in the radial direction. The connecting portion 68 connects the opposing portion 62 and the regulating portion 67 on the radial outside of the flange portion 61. When the processing of the material to be processed in the gasification apparatus 1 is stopped, if the rotating cylindrical portion 11 contracts in the axial direction, the flange portion 61 and the regulating portion 67 come into contact with each other. This prevents the flange portion 61 and the opposing portion 62 from moving excessively apart.

[0057] As described above, the gasification apparatus 1 includes the rotating cylindrical portion 11, the flange portion 61, the opposing portion 62, the cover portion 63, the first seal member 641, the second seal member 642, and the gas filling portion 65. The rotating cylindrical portion 11 is cylindrical and centered on the central axis J1. It has openings (the supply port 111 and the discharge port 112 in the above example) at both axial ends. The rotating cylindrical portion 11 heats the material to be treated inside while rotating about the central axis J1. The flange portion 61 is provided at one axial end of the rotating cylindrical portion 11 and extends radially outward. The opposing portion 62 is an annular, non-rotating member that faces the flange portion 61 on that axial side. The cover portion 63 covers the space extending from the opposing portion 62 to that axial side. The first seal member 641 and the second seal member 642 are annular and are provided between the flange portion 61 and the opposing portion 62.

[0058] In the gasifier 1, thermal expansion of the rotary tubular portion 11 in the axial direction causes the first seal member 641 and the second seal member 642 to be crushed between the flange portion 61 and the opposing portion 62, thereby sealing the gap between the flange portion 61 and the opposing portion 62 with the first seal member 641 and the second seal member 642. The gas filling unit 65 fills the gap between the first seal member 641 and the second seal member 642 with a predetermined gas (auxiliary gas in the above example) through the gas flow path 623 provided in the opposing portion 62. As a result, high sealing performance can be easily achieved without a configuration in which seal members face each other in the axial direction or without using seal members with complex shapes. A ring-shaped third seal member 643 may be provided inside the second seal member 642 between the flange portion 61 and the opposing portion 62, achieving even higher sealing performance. Depending on the design of the gasifier 1, four or more seal members may be provided.

[0059] Preferably, the gasification apparatus 1 further includes a restricting portion 67 that faces the other axial side of the flange portion 61, and a connecting portion 68 that connects the opposing portion 62 and the restricting portion 67 on the radially outer side of the flange portion 61. When the rotating cylindrical portion 11 contracts in the axial direction, the flange portion 61 and the restricting portion 67 come into contact with each other. This prevents the flange portion 61 and the opposing portion 62 from moving too far apart, which can prevent unwanted matter from getting between them.

[0060] Preferably, the restricting portion 67 has a roller 671 that can rotate around an axis extending in the radial direction. This allows the flange portion 61 and the restricting portion 67 to be in rolling contact with each other even when they come into contact with each other when the rotating cylindrical portion 11 rotates, thereby preventing excessive load from being applied to the rotation of the rotating cylindrical portion 11.

[0061] Preferably, the cover part 63 includes a fixed part 631 disposed on one axial side of the opposing part 62, and an expandable tube 632 that is cylindrical and centered on the central axis J1 and connects the opposing part 62 and the fixed part 631. The flange part 61 extends radially outward from the edge of the opening at the one end of the rotating cylindrical part 11, and the gas contains water vapor. In this gasifier 1, the gas supplied between the first seal member 641 and the second seal member 642 does not pass through the expandable tube 632 but flows into the rotating cylindrical part 11, thereby suppressing water condensation in the expandable tube 632. Furthermore, the fixed part 631 preferably includes a drain port 633 that drains liquid in the expandable tube 632 to the outside. This allows the liquid (e.g., condensed water) to be properly discharged even when liquid accumulates in the expandable tube 632. The drain port 633 may be provided in any location on the cover part 63.

[0062] The gasification apparatus 1 can be modified in various ways.

[0063] The gas flow path 623 through which the auxiliary gas is supplied does not necessarily have to be formed in the opposing portion 62, but may be provided in the flange portion 61. In this case, too, by providing a gas outlet 624 of the gas flow path 623 on the flange portion 61 between the first seal member 641 and the second seal member 642, it is possible to fill the space between the first seal member 641 and the second seal member 642. Also, an annular groove for holding the first seal member 641 and the second seal member 642 (and the third seal member 643) may be provided in the flange portion 61. In the second blocking portion 6b of FIG. 5, the gas outlet 624 may be provided between the second seal member 642 and the third seal member 643.

[0064] The flange portion 61 may be directly fixed to the rotating cylindrical portion 11, as in the case of the first closing portion 6a, or may be indirectly fixed to the rotating cylindrical portion 11, as in the case of the second closing portion 6b. The flange portion 61 may also have a structure in which it extends radially inward. The fixed portion 631 of the first closing portion 6a is fixed to the casing 30, and the fixed portion 631 of the second closing portion 6b is fixed to the separation portion 16, but the fixed portion 631 may also be fixed to another member whose position is fixed. As described above, the structures of the flange portion 61, the opposing portion 62, the cover portion 63, the restricting portion 67, the connecting portion 68, etc. may be changed as appropriate.

[0065] The central axis J1 of the rotating cylindrical portion 11 is preferably horizontal, but may be tilted to some extent as long as the material to be treated is agitated inside by rotation of the rotating cylindrical portion 11 about the central axis J1. The rotating cylindrical portion 11 is not limited to a cylindrical shape as long as it is tubular and centered on the central axis J1. The supply port 111 for the material to be treated of the rotating cylindrical portion 11 may be in various forms as long as it is provided at one end in the axial direction. Preferably, the supply port 111 is provided on the central axis J1. The same applies to the discharge port 112.

[0066] In the above embodiment, both the pyrolysis section 151 and the reforming section 152 are indirectly heated by the high-temperature gas flowing through the cylindrical space 120. However, in the reforming section 152, which uses the heat from partial combustion of the pyrolysis gas, indirect heating by the high-temperature gas may be omitted. If the required temperature in the reforming section 152 can be ensured by indirect heating alone, partial combustion in the reforming section 152 may be omitted. A reforming catalyst (e.g., a nickel-based reforming catalyst) may be installed in the reforming section 152 to perform reforming that decomposes tar in the pyrolysis gas. If a reforming catalyst (e.g., a nickel-based reforming catalyst) is installed, it is not necessary to supply steam.

[0067] In the gasification apparatus described above, the agitation section 15 includes, in order from the supply port 111 toward the discharge port 112, a pyrolysis section 151 and a reforming section 152, but the agitation section 15 does not need to be clearly divided into the pyrolysis section 151 and the reforming section 152. The reforming section 152 may be omitted from the agitation section 15, in which case the mixed gas introduction section 14 is also omitted. The agitation section 15 only needs to have the function of agitating the material to be treated within the rotating cylindrical section 11, but preferably the agitation section 15 is fixed within the rotating cylindrical section 11, and the material to be treated is agitated by utilizing the rotation of the agitation section 15 caused by the rotation of the rotating cylindrical section 11 and gravity.

[0068] The configuration including the rotating cylindrical portion 11, the flange portion 61, the opposing portion 62, the cover portion 63, the first sealing member 641, the second sealing member 642, and the gas filling portion 65 may be employed in various types of rotary kilns that heat the material to be treated, and is not limited to gasification apparatuses. The rotary kiln may be an internal combustion type.

[0069] The configurations in the above-described embodiment and each modification may be combined as appropriate as long as they are not mutually contradictory. [Explanation of symbols]

[0070] 1 Gasifier 11 Rotating cylindrical part 61 Flange 62 Opposing part 63 Cover 65 Gas filling section 67 Regulatory Department 68 Connection 111 Supply port 112 Outlet 623 Gas flow path 631 Fixed part 632 Telescopic tube 633 Drainage port 641 First sealing member 642 Second seal member 643 Third seal member 671 Laura J1 center axis

Claims

1. A rotary kiln for heating a material to be treated, a rotating cylindrical part that is cylindrical about a central axis, has openings at both ends in an axial direction parallel to the central axis, and heats the object to be treated inside while rotating about the central axis; a flange portion provided at one end of the rotary cylindrical portion in the axial direction and extending in a radial direction; a non-rotating member having an annular opposing portion facing the flange portion on the one side in the axial direction; a cover portion that covers a space on the one side in the axial direction from the opposing portion; a first annular seal member provided between the flange portion and the opposing portion; a second annular seal member provided inside the first seal member between the flange portion and the opposing portion; a gas filling portion that fills a predetermined gas between the first seal member and the second seal member that are crushed between the flange portion and the opposing portion due to thermal expansion of the rotary cylindrical portion in the axial direction, via a gas flow path that is provided in the opposing portion or the flange portion; A rotary kiln equipped with:

2. The rotary kiln according to claim 1, A rotary kiln, wherein each of the first seal member and the second seal member is a braided packing.

3. The rotary kiln according to claim 1, a restricting portion facing the other side of the flange portion in the axial direction; a connecting portion that connects the opposing portion and the restricting portion on a radially outer side of the flange portion; Furthermore, The rotary kiln, wherein the flange portion and the regulating portion come into contact with each other when the rotating cylindrical portion contracts in the axial direction.

4. The rotary kiln according to claim 3, A rotary kiln, wherein the regulating portion has a roller that can rotate around an axis extending in the radial direction.

5. The rotary kiln according to claim 1, The rotary kiln further includes an annular third seal member provided inside the second seal member between the flange portion and the opposing portion.

6. A rotary kiln according to any one of claims 1 to 5, The cover portion is a fixed portion disposed on the one side in the axial direction with respect to the opposing portion; an expandable tube having a cylindrical shape centered on the central axis and connecting the opposing portion and the fixed portion; Equipped with the flange portion extends radially outward from an edge of the opening at the one end of the rotary cylindrical portion, A rotary kiln wherein the predetermined gas contains water vapor.

7. A rotary kiln according to any one of claims 1 to 5, The cover portion is a fixed portion disposed on the one side in the axial direction with respect to the opposing portion; an expandable tube having a cylindrical shape centered on the central axis and connecting the opposing portion and the fixed portion; Equipped with a drain port for discharging liquid from the expandable tube to the outside is provided at any location of the cover portion; A rotary kiln wherein the predetermined gas contains water vapor.

Images