JP4096542B2 - Rotary kiln seal mechanism - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rotary kiln sealing mechanism suitable for use in a rotary kiln used for firing chemicals and cement.
[0002]
[Prior art]
In general rotary kilns, raw materials supplied from the inlet side of the rotating cylinder are moved to the outlet side by utilizing the rotation and inclination of the rotating cylinder, and then baked and discharged by hot gas blown into the rotating cylinder. To do.
The rotating cylinder is inserted into or supported by a frame such as a housing fixed to the foundation so that both ends of the rotating cylinder can rotate, but from the gap between the housing that is a fixed member and the rotating cylinder that is a rotating member, Since the hot gas blown into the rotating cylinder may leak, a sealing mechanism is provided between the housing and the rotating cylinder so as to cover the gap.
[0003]
In particular, an external heating type rotary kiln in which a raw material and a heated gas are separated is generally structured to be heated by inserting an inner cylinder, which is a rotating cylinder for transferring the raw material, into a heating furnace that is a fixed member. Yes, since there is a gap between the rotating part of the inner cylinder and the fixed heating furnace, it is necessary to dispose a seal mechanism, and at the same time, when the raw material charged into the inner cylinder is dried and fired In many cases, gas is generated. In such a case, gas leaks from the gap between the rotating portion of the inner cylinder and the fixed heating furnace as well as the gantry supporting both ends of the inner cylinder. There is a possibility that the seal mechanism is frequently used.
[0004]
The structure of a conventional sealing mechanism used in the rotary kiln as described above will be briefly described below.
In the conventional sealing mechanism, it is common to form a seal portion by arranging a seal member on each of the rotating member and the fixed member and bringing the respective seal members into airtight contact with each other. It is generally known to use a seal mechanism having a structure as shown in FIG. 6 as an example of a seal mechanism of a rotary kiln in which the dimensions of the rotating member and the fixed member change by expansion.
The seal mechanism shown in FIG. 6 absorbs the change in the dimensions by using the expansion coil 210 and the pressing coil spring 202 through which the guide lot 205 is inserted, so that the seal plate 215 and the seal plate 207 as seal members are absorbed. Are configured to abut against each other in an airtight manner.
[0005]
Further, as an example of another conventional sealing mechanism that can absorb the change in dimensions and keep it airtight, a sealing mechanism as shown in Japanese Patent Laid-Open No. 9-217989 is known.
The sealing mechanism disclosed in the above publication is provided with a sliding contact surface (seal surface) that is substantially orthogonal to the rotation axis of the rotation-side annular member, and the seal surface is hermetically sealed with a second annular member through an expansion tube. This is a rotary kiln seal mechanism in which an annular moving flange connected to the pressure member is brought into pressure contact with the force of an urging member and the rotating member and the fixed member are hermetically connected.
[0006]
[Problems to be solved by the invention]
However, in the conventional seal mechanism shown in FIG. 6, the seal surface of the seal plate 207 disposed on the rotary cylinder 250 side is inclined when the entire rotary cylinder is deformed by the influence of heat during operation. However, the seal surface of the seal plate 215 disposed on the fixed member side is restrained from being inclined due to the guide rod 205 that is passed through the coil spring 202, and the contact between the seal members becomes poor. There was a problem that defects occurred.
Similarly, in the conventional sealing mechanism disclosed in Japanese Patent Laid-Open No. 9-217989, when the contact surface of the sealing member disposed on the inner cylinder side is inclined, the sealing member disposed on the fixed member side is inclined. The problem was that seal failure would occur due to the inability to do this.
[0007]
In addition, the above-described two conventional seal mechanisms abut the mutual seal surfaces by the elastic recovery force of the coil spring, and the contact force of the seal surface (sometimes referred to as seal surface pressure) by the amount of compression of the coil spring. It is a structure that makes a difference.
For this reason, when used in a rotary kiln where the dimensional relationship between the rotating member and the fixed member changes, it is difficult to keep the sealing surface constant at all times, and it is necessary and sufficient for sealing when the compression amount of the coil spring is the smallest. When trying to maintain the seal surface pressure, when the compression amount of the coil spring is large, the seal surface pressure becomes too high, so that the seal surface is worn out in a short period of time.
[0008]
A specific example will be described with reference to the seal mechanism shown in FIG. 6. The conventional seal mechanism disposed between the housing 201 and the rotary cylinder 250 is operated with a rotary kiln having a short rotary cylinder because the rotary cylinder is not sufficiently heated. When the compression amount of the coil spring 202 is adjusted so as to obtain a sufficient sealing capability at the time, when the temperature of the rotary cylinder 250 rises and the rotary cylinder 250 becomes longer during the steady operation of the rotary kiln, the seal plate 207 Since the coil spring is moved to the housing 201 side, the amount of compression of the coil spring becomes too large, the sealing surface pressure becomes too high, and the sealing surface is worn away.
[0009]
In view of the above problems, the present invention provides a sealing mechanism for a rotary kiln that can reliably seal even if the rotary kiln is bent slightly from the start to the end of the operation, for example, when the rotary kiln is bent slightly. For the purpose.
[0010]
[Means for Solving the Problems]
In order to solve the above-described problems, a rotary kiln seal mechanism according to the present invention is (1) a rotary kiln seal mechanism disposed between a rotary kiln rotary member and a fixed member, and is provided on an outer periphery of the rotary member. A first seal ring provided on both surfaces with seal surfaces substantially orthogonal to the rotation axis of the rotary member, and a mounting seat attached from the fixed member via the first telescopic tube via a biasing member. A second seal ring, and two second seal rings are arranged so as to sandwich the first seal ring from both sides, and the mounting is performed between the mounting seat and the second seal ring. An annular second telescopic tube extending along the seat and the second seal ring is disposed to hermetically connect between the mounting seat and the second seal ring, and the second seal ring is attached by the biasing member. First The seal part was formed by pressing against the seal ring.
[0012]
(2) In the sealing mechanism of the rotary kiln described in (1), the expandable tube is a metal bellows.
[0013]
(3) In the rotary kiln sealing mechanism according to (1) or (2) , the rotary kiln is an externally heated rotary kiln.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a preferred example of an embodiment according to the present invention will be described in detail with reference to the drawings.
1 to 5 relate to an embodiment of the present invention, and FIG. 1 is a cross-sectional view of an essential part of a seal mechanism of a rotary kiln. FIG. 2 is a conceptual diagram for specifically explaining the mounting state of the seal mechanism with respect to the rotary kiln, and FIG. 3 is an explanatory diagram illustrating a perspective view of a state in which part of the seal mechanism is cut away in order to explain the structure of the seal mechanism. It is. FIG. 4 is a layout diagram for explaining an example of the seal mechanism arrangement used in the rotary kiln, and FIG. 5 is a layout diagram for explaining an example of the seal mechanism arrangement used in the external heating type rotary kiln. FIG. 6 is a cross-sectional view of an essential part for explaining a sealing mechanism of a rotary kiln having a conventional structure.
[0015]
Hereinafter, the structure of the rotary kiln and the arrangement of the seal mechanism 1 will be briefly described with reference to FIGS. 4 and 5.
The rotary kiln 100 shown in FIG. 4 includes an inlet-side housing 211, an outlet-side housing 201, a rotating cylinder 250, a rotation support device 217, and the like. The rotating cylinder 250 has both ends inserted into the housing 201 and the housing 211. In this state, the rotary support device 217 is driven to rotate.
The raw material charged from the housing 211 side is fired and discharged by the heated gas blown into the rotary cylinder 250 by the burner disposed in the outlet-side housing 201 while moving to the outlet side by the rotation of the rotary cylinder 250. .
In the rotary kiln 100 as shown in FIG. 4, the rotary kiln seal mechanism 1 is disposed between the rotating portion of the rotary cylinder and the housings 201 and 211 which are fixed members.
[0016]
The rotary kiln 101 shown in FIG. 5 is called an externally heated rotary kiln 101. Unlike the rotary kiln 100 described above, the structure is such that the heated gas heated by the burner is not brought into direct contact with the raw material, and the raw material is heated and fired. It is. In the externally heated rotary kiln 101 shown in FIG. 5, the seal mechanism 1 is disposed between the rotary cylinder 250 and the housings 201 and 211 that are fixed members, and between the rotary cylinder 250 and the annular heating furnace.
[0017]
Next, a preferable example of the configuration of the seal mechanism 1 will be described.
The seal mechanism 1 shown in FIG. 1 is roughly divided into a seal member connected to the housing 201 side and a seal member connected to the rotary cylinder side.
The seal member disposed on the rotary cylinder 250 side is an annular seal ring 7 (also referred to as the first seal ring 7) provided with seal surfaces orthogonal to the rotation axis of the rotary cylinder 250 on both surfaces. Thus, the seal ring 7 projects from the outer peripheral surface of the rotating cylinder like a partition plate.
The seal ring 7 is obtained by simply polishing both surfaces of a steel plate formed in an annular shape to improve the surface roughness, and is connected to the rotating cylinder 250 by welding or connected to the rotating cylinder 250. They were connected by mounting bolts (not shown).
[0018]
As shown in FIGS. 1 and 2, the first telescopic tube 22 (in this embodiment, a metal bellows) is attached to one end of the housing 201 so as to cover the outer periphery of the rotary cylinder 250 . A mounting seat 4 for a seal ring 3 (also referred to as a second seal ring 3) is disposed on the opposite side of the expansion tube 22 from the housing 201 mounting side via a flange 20 and a flange 21. The seal ring 3 is obtained by simply polishing both surfaces of an annular copper alloy plate to improve the surface roughness.
[0019]
Further, in the present embodiment, in order to provide a preferable configuration that facilitates maintenance and replacement of the above-described seal rings 3 and 7 etc., the flange 20 is welded and attached to one end of the first expansion tube 22, by attaching by welding a flange 21 at one end of the mounting seat 4, the flange 20 and the first telescoping tube 22 and the attachment seat 4 as configured for connecting a bolt (not shown) the flange 21 to allow detachable freely The configuration applicable to the present invention is not limited to this, and the mounting seat 4 may be directly connected to the first telescopic tube 22 by welding without using a flange or the like.
[0020]
Further, in the present embodiment, a metal bellows is used as the first telescopic tube 22 in order to obtain a preferable configuration excellent in heat resistance. However, the present invention is not limited to this, and when a high heat resistant temperature is not required. Alternatively, a tubular material that can be expanded and contracted, such as a cloth bellows or a resin expansion / contraction tube, may be used.
[0021]
The mounting seat 4 used in the present embodiment has an annular L-shaped steel material having a structure as shown in its cross section in FIG. As a shape opening toward the side, the first seal ring 7 was disposed in the opened portion.
In the present embodiment, the mounting seat 4 can be divided into two parts so that the seal ring and the urging machine 10 to be described later can be easily maintained and replaced. However, the configuration applicable to the present invention is not limited to this, and may be a divided structure of two or more parts or an integrated structure.
[0022]
Then, two second seal rings 3 are disposed so as to sandwich the first seal ring from both sides, and the second seal ring 3 is connected to the mounting seat 4 via a biasing device 10 which is a biasing member. . Then, the sealing portion is formed by the two sealing rings 3 sandwiching the sealing surface of the first sealing ring 7 from both sides by the pressing force of the urging member. When the rotary cylinder 250 rotates, the first seal ring 7 is driven and rotated. At the time of the rotation, the two seal rings 3 sandwich the sealing surface of the first seal ring 7 from both sides. Since the seal surfaces are in contact with each other while sliding with each other to form a seal portion, the rotating member and the fixed member can be connected in an airtight manner.
[0023]
As shown in FIG. 1 in detail, the urging machine 10 that is an urging member includes a pressing ring 17, a second telescopic tube 15, a coil spring 12, and a pressing bolt 11, and the elasticity of the plurality of coil springs 12. By pressing the pressing ring 17 against the second seal ring 7 by force, the second seal ring 3 can be pressed against the first seal ring.
[0024]
Furthermore, in this embodiment, the compression amount of the coil spring 12 is configured so as to be freely adjustable by the forward / backward movement of the pressing bolt 11 disposed at one end of the coil spring 12, and the mounting seat 4 and the second seal. A second telescopic tube 15 (a metal bellows in the present embodiment) is disposed between the ring 3 and the mounting seat and the second seal ring are hermetically connected.
[0025]
In the present embodiment, the urging device 10 as the urging member is configured by the above configuration, but the configuration of the urging device 10 is not limited to this, and the mounting seat 4, the second seal ring 3, and the like. Any structure may be used as long as the second seal ring 3 is pressed against the first seal ring while keeping the airtightness between the first seal ring and the second seal ring 3 directly by the coil spring 12 without using the pressing ring 17, for example. Alternatively, the second seal ring 3 may be pressed by using, for example, a disc spring instead of the coil spring 12.
[0026]
Further, in the present embodiment, a metal bellows that is preferable in terms of heat resistance is disposed between the mounting seat 4 and the second seal ring 3 as the second telescopic tube 15, so that the mounting seat 4 and the second sealing ring 15 are arranged. The gas is heated between the seal ring 3 and the gas heated by the housing 201 is configured to prevent the gas from passing through the seal mechanism 1 and exiting to the outside. However, the present invention is not limited to this, and a high heat-resistant temperature is not required. In such a case, a tubular material that can be expanded and contracted, such as a cloth bellows or a resin expandable tube, may be used. Further, as a configuration in which a part of the pressing ring 17 is slidably fitted into a hole drilled in the mounting seat 4, the fitting seat and the second seal ring are hermetically connected by the fitting portion. It is good also as a structure.
[0027]
According to the above-described preferred embodiment of the present invention, even if the rotary cylinder 250 is deformed and the seal surface of the first seal ring 7 is inclined, the expansion / contraction state of the first expansion / contraction tube 22 is maintained. By changing easily, the entire inclination of the mounting seat 4 changes in accordance with the inclination of the first seal ring 7, so that the seal surfaces always come into contact with each other and slide in a good state. Therefore, it is possible to always perform a good seal, and it is difficult to cause a seal failure which is a problem of the above-described prior art.
[0028]
Even if the length of the rotary cylinder 250 is changed by heating and cooling, since the change in the length is absorbed by the first telescopic tube 22, the amount of compression of the coil spring 12 is almost always changed. Absent. Therefore, the problem of a change in the seal surface pressure that occurs when the length of the rotary cylinder 250 or the like is changed by heating and cooling is prevented, and the rotary kiln is slightly bent from the start to the end of the rotary kiln. Even if deformation occurs, such as bending at, it can be surely sealed.
[0029]
Further, in the present embodiment, the urging machine 10, the seal ring, etc. are provided by making the first telescopic tube 22 and the attachment seat 4 detachable and making the attachment seat 4 detachable as a divided structure. It is particularly preferable in that it is easy to carry out maintenance, inspection, replacement, etc.
[0030]
Moreover, it is extremely effective to apply the present invention to an external heating type rotary kiln in which many sealing mechanisms must be used.
[0031]
【The invention's effect】
As explained above, according to the seal mechanism of the first invention of the present application, the seal surface of the first seal ring is inclined by deformation such as part of the rotary kiln being bent due to the influence of heat during operation. However, since the first telescopic tube that connects the mounting seat to the fixing member is easily deformed, and the inclination of the entire mounting seat is changed in accordance with the inclination of the first seal ring, The inclination of the second seal ring is always constant and can slide with good contact. Therefore, even if the seal surface of the first seal ring is inclined, good sealing is possible.
[0032]
Further, even if the dimensions of the rotating member and the fixed member change due to heating and cooling, the amount of compression of the biasing member does not change by absorbing the change in the dimension with the telescopic tube. Therefore, even if the rotary kiln is bent slightly, for example, from the start to the end of the operation of the rotary kiln, it can be surely sealed.
[0033]
In the first invention, if the second telescopic tube is further disposed between the mounting seat and the second seal ring, the mounting seat and the second seal ring can be effectively formed with a very simple configuration. If the second telescopic tube is made of a metal bellows, a sealing mechanism having high heat resistance can be obtained.
[0034]
In particular, it is extremely effective to apply the above-described invention to an externally heated rotary kiln that requires a lot of sealing mechanisms.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a main part of a seal mechanism of a rotary kiln according to an embodiment of the present invention.
FIG. 2 is a conceptual diagram for specifically explaining the attachment state of the seal mechanism to the rotary kiln according to the embodiment of the present invention.
FIG. 3 is an explanatory view perspectively illustrating a state in which a part of the seal mechanism is cut away in order to explain the structure of the seal mechanism.
FIG. 4 is a layout diagram illustrating an example of a seal mechanism layout used in a rotary kiln.
FIG. 5 is a layout diagram for explaining an example of a seal mechanism layout used in an external heat type rotary kiln.
FIG. 6 is a cross-sectional view of a main part for explaining a sealing mechanism of a conventional rotary kiln.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Seal mechanism 3 2nd seal ring 4 Mounting seat 7 1st seal ring 10 Energizing machine 11 Pressing bolt 12 Coil spring 15 Telescopic tube 20 Flange 21 Flange 22 Telescopic tube 17 Pressing ring 100 Rotary kiln 201 Housing 211 Housing 250 Rotary cylinder

Claims (3)

In a rotary kiln seal mechanism disposed between a rotary member and a fixed member of a rotary kiln, there is provided a first provided with seal surfaces provided on the outer periphery of the rotary member and substantially orthogonal to the rotation axis of the rotary member. A seal ring; and a second seal ring connected to the mounting seat attached from the fixing member via the first telescopic tube via the biasing member, and sandwiching the first seal ring from both sides In this manner, two second seal rings are arranged , and an annular second telescopic tube extending along the mounting seat and the second seal ring is disposed between the mounting seat and the second seal ring. A rotary kiln seal mechanism in which the mounting seat and the second seal ring are hermetically connected and the second seal ring is pressed against the first seal ring by the biasing member to form a seal portion. Sealing mechanism of the rotary kiln of claim 1 wherein said second telescopic tube and metal bellows. The rotary kiln sealing mechanism according to claim 1 or 2, wherein the rotary kiln is an externally heated rotary kiln.

Images