JP2006078149A - Sealing structure of rotary kiln - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sealing structure of a rotary kiln that can obtain stable sealing performance by keeping the surface pressure of a sliding section of a sealing face high, can extend the service life of a seal member, and can prevent reduction of the sealing performance even when the wear of the seal member progresses. <P>SOLUTION: An annular disk plate 44 is disposed at an end of the kiln body, two grooves having a pressurizing means and two seal rings 2 to be mounted to these are disposed on the sealing face side of an annular pressing plate 5 connected to a fixed hood 36 via a bellows 47, and gas or liquid is introduced among the disk plate, the pressing plate, and two grooves, thereby sealing the inside and outside of the kiln. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to an improvement in a seal structure at a joint portion between an end portion of a kiln main body of a rotary kiln used for heat treatment of various raw materials and a fixed hood.

A specific example of the rotary kiln as described above is disclosed, for example, in JP-A-3-251683. As shown in FIG. 3, the apparatus includes a long cylindrical kiln main body 31 that is placed horizontally, and the kiln main body 31 includes annular tire portions 32. 32 portions are supported from below so as to roll freely. Furthermore, the kiln main body 31 can be rotated by driving a sprocket 33 provided on the outer peripheral surface by a motor (not shown).

Raw material powder is supplied to the kiln main body 31 through an inlet-side hood portion 34 on the left end side in the drawing, and the raw material powder is sent to the right end side as the kiln main body 31 rotates. At this time, a predetermined heat treatment is given by the heating means 35 provided on the outer periphery of the kiln main body 31, and the product powder after the heat treatment is collected through the outlet end hood portion 36 on the right end side.

Sealing devices 37 and 38 for sealing the inside of the kiln body 31 from the external atmosphere are provided between the hood portions 34 and 36 and the kiln body 31. As such a sealing device, in addition to airtightness with respect to the relative rotational motion at the portion where the fixed portion and the rotating portion face each other, at least one end side changes the length of the kiln body 31 in the rotational axis direction due to thermal expansion. It must be acceptable. For this purpose, in the sealing device 38 on the right end side in the above device, as shown in FIG. 4, an annular frame body 41 is provided on the outer peripheral side of the end portion of the kiln body 31. The frame body 41 is supported by a rail 42 extending from the outlet side hood portion 36 so as to be movable in the rotation axis direction while maintaining a position substantially concentric with the kiln main body 31.

On the left end side of the frame body 41, as shown in FIG. 5, a ring-shaped seal plate 43 extending in the radial direction is provided. On the other hand, a disc-shaped disc plate 44 facing the seal plate 43 is provided on the outer peripheral surface of the kiln main body 31, and in order to keep the distance between the disc plate 44 and the seal plate 43 constant, A pair of guide rollers 45 and 45 are attached to the plate 43 so that the outer end side of the disc plate 44 is sandwiched and rotatably guided.

Between the sealing plate 43 and the disc plate 44 held at a constant interval in this way, a lip-type sealing material 46 having an approximately “<”-shaped cross section made of an elastic body is disposed. The lip type seal material 46 is fixed to the disk plate 44 side with the inner end side pressed against the seal plate 43 with the outer end side being pressed against the seal plate 43, whereby the rotating kiln body 31 and the non-rotating frame are fixed. Airtightness with respect to relative rotational motion with the body 41 is provided.

Further, the frame body 41 follows the axial displacement on the end side of the kiln main body 31 due to the above structure, but the frame body 41 is allowed to move in the axial direction, and the frame body 41 and the outlet side are allowed to move. In order to seal between the hood part 36, both 41 and 36 are connected with the bellows 47 which can be expanded-contracted in the shape of a bellows, and, thereby, the whole from the kiln main body 31 to the exit side hood part 36 can be carried out from an external atmosphere It is configured to seal.

However, in the above apparatus, the lip type sealing material 46 itself needs to have elasticity, and in most cases, is constituted by a rubber member. Since the pressure cannot be kept high, there is a problem in that the sealing performance tends to be insufficient, and gas leakage from the inside and conversely, external air easily enters the furnace.

Further, since the lip-type sealing material 46 always rotates and slides with the sealing plate 43 and wears with the operation time, it needs to be replaced periodically. However, the rubber member has a short life and is worn as it wears. There was a problem that the sealing performance deteriorated.

The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to obtain a stable sealing performance by maintaining a high surface pressure of the sliding portion, thereby extending the life of the sealing member. It is another object of the present invention to provide a rotary kiln seal structure that can prevent the seal performance from being deteriorated even if the seal member is worn.

In order to achieve the above object, the rotary kiln seal structure of the present invention is provided with a cylindrical kiln main body for transferring an object to be processed while rotating, and both ends of the kiln main body, respectively. A fixed hood, an annular disk plate provided at at least one end of the kiln main body, an annular pressing plate connected to the corresponding fixed hood via an elastic bellows, and the pressing plate A rotary kiln seal structure in which a slidable seal member is disposed between the disk plate and the pressing plate and hermetically sealed. A first groove having a pressurizing means which is driven from the outside and can generate arbitrary pressing in the direction of the rotation axis of the kiln main body on the seal surface side of the pressing plate, and the outer peripheral surface make one round A first seal ring that is mounted in the first groove and is movable in the direction of the rotation axis of the kiln main body, and is driven from the outside and the kiln. A second groove having a pressurizing means capable of generating an arbitrary press in the direction of the rotation axis of the main body, and a seal member that makes one round of the outer peripheral surface, and is attached to the first groove and the pressurizing means A second seal ring that can move in the direction of the rotation axis of the kiln main body by abutting with, and an introduction hole for introducing gas or liquid from the outside between the first groove and the second groove, Means for injecting gas or liquid into the introduction hole and means for controlling the pressure of the gas or liquid injected into the introduction hole are provided.

According to a second aspect of the present invention, in the first aspect, the pressurizing means is composed of a plurality of pistons that are driven by the pressure of gas or liquid injected from a driving hole penetrating the outside and sealed from the outside. It is said.

According to a third aspect of the present invention, the gas or liquid injected into the drive hole and the introduction hole in the second aspect is any one of air, nitrogen, water vapor, water, and oil.

According to a fourth aspect of the present invention, the gas or liquid injected into the drive hole according to the second aspect is any one of air, nitrogen, water vapor, water, and oil, and the internal pressure of the introduction hole is higher than the internal pressure of the kiln body. It is characterized by having means for reducing the size and detoxifying the atmosphere gas in the kiln main body flowing out from the introduction hole.

A fifth aspect of the present invention is characterized in that in any one of the first to fourth aspects, the first seal ring and the second seal ring are made of carbon or steel.

In the above configuration, since two seal portions are formed concentrically on the seal surface side of the annular pressing plate, double sealing performance can be obtained as compared with the conventional seal structure using only one seal portion. In addition, a gas or liquid such as nitrogen or water having a pressure higher than the furnace pressure is sealed between the two seal portions, so that gas leaks from the inside of the furnace or, conversely, external air enters the furnace. Intrusion and the like can be completely prevented, and a total triple sealing performance can be obtained as compared with the conventional seal structure.

In addition, since two seal portions are formed concentrically on the seal surface side of the annular pressing plate, double sealing performance can be obtained compared to a conventional seal structure using only one seal portion. If the internal pressure of the introduction hole is made smaller than the internal pressure of the kiln main body and the atmosphere gas in the kiln main body flowing out from the introduction hole is detoxified, a means between the two seal portions is provided. Since the pressure is also smaller than the internal pressure of the kiln body, the gas leaking from the inside of the kiln and the air entering from the outside are both absorbed and discharged from the introduction hole and detoxified by the detoxifying means. In addition, it is possible to completely prevent gas leakage from the inside of the furnace and, conversely, outside air from entering the furnace, resulting in a total triple sealing performance compared to the conventional seal structure and environmental pollution. Prevention it is possible to.

The surface pressure of the seal surface formed between the first and second seal rings installed on the two seal portions and the disk plate is determined by the rear portion of the first and second seal rings. For example, the piston driven from the outside installed in is obtained by pushing the first and second seal rings in the direction of the rotation axis of the kiln body, that is, in the direction of the disk plate. Therefore, by controlling the driving force of the piston from the outside, the surface pressure of the seal surface can be freely set, and a constantly stable surface pressure required for sealing can be obtained.

As a result, the sealing performance is greatly improved compared to the conventional sealing structure, and it is possible to completely prevent gas leakage from the inside and, on the contrary, the intrusion of external air into the furnace, and also prevent environmental pollution. It becomes.

Furthermore, as the material of the first and second seal rings, a wide variety can be selected. For example, by selecting a carbon or steel material that is hard and has good slidability, compared with the rubber member of the conventional example. Thus, the life of the seal ring can be dramatically improved. Thereby, the frequency | count of periodic replacement | exchange of a seal ring will decrease, and the sealing structure of a rotary kiln with easy maintenance can be provided.

In addition, if the piston is constituted by a plurality of pistons driven by the pressure of a gas or liquid such as nitrogen or water injected from a driving hole penetrating the outside and sealed from the outside, for example, Even when wear of the second seal ring progresses and its thickness decreases, the plurality of pistons can always push the first and second seal rings in the direction of the disk plate with a constant pressure. Therefore, it is possible to provide a rotary kiln seal structure that can prevent the seal performance from deteriorating even when the wear of the seal member proceeds.

Embodiments of the present invention will be described below. As shown in FIG. 3, the present invention includes a long cylindrical kiln main body 31 that is placed horizontally, and the kiln main body 31 has annular tire portions 32 and 32 provided on the outer peripheral surfaces of both end portions thereof. This part is supported from below so that it can roll freely. Furthermore, the kiln main body 31 can be rotated by driving a sprocket 33 provided on the outer peripheral surface by a motor (not shown).

Raw material powder is supplied to the kiln main body 31 through an inlet-side hood portion 34 on the left end side in the drawing, and the raw material powder is sent to the right end side as the kiln main body 31 rotates. At this time, a predetermined heat treatment is given by the heating means 35 provided on the outer periphery of the kiln main body 31, and the product powder after the heat treatment is collected through the outlet end hood portion 36 on the right end side.

Sealing devices 37 and 38 for sealing the inside of the kiln main body 31 from the external atmosphere are provided between the hood portions 34 and 36 and the kiln main body 31. The above points are based on a conventionally known configuration.

The differences and features of the present invention from the prior art will be described below. As shown in the cross-sectional view of the main part of FIG. 1, in the present invention, an annular disk plate 44 is provided on at least one end of the kiln main body 31, and a fixed hood 36 corresponding thereto is provided with a telescopic bellows 47. Connected to each other, and a means for fixing the presser plate 5 rotatably along the rotation direction of the disk plate.

Specifically, as the means for fixing in a freely rotating manner, as shown in FIGS. 2A and 2B, a pair of guide rollers 45 for sandwiching and guiding the outer end side of the disk plate 44 so as to rotate freely. A plurality of roller brackets 7 having 45 are provided around the pressing plate 5.

With such a structure, the gap distance d between the disk plate 44 and the pressing plate 5 in FIG. 1 can be kept constant irrespective of the change in the length of the kiln body 31 in the rotational axis direction due to thermal expansion. it can. The change in the length of the kiln main body 31 is absorbed by the bellows 47 while maintaining the airtightness in the furnace. The reason why the gap d needs to be kept constant is that the surface pressure of the seal surface formed between the first seal ring 4 and the second seal ring 2 described below and the disk plate 44 is caused by thermal expansion. This is to prevent being affected.

Further, according to the present invention, the first groove 3 having pressurizing means which is driven from the outside and can generate arbitrary pressing in the direction of the rotation axis of the kiln main body 31 is provided on the seal surface facing the disc plate 44 of the pressing plate 5. A first seal ring having a seal member 9 that makes one round of the outer peripheral surface, mounted in the first groove 3, and movable in the direction of the rotation axis of the kiln body 31 by contacting the pressurizing means 4, a second groove 1 having a pressurizing means that is driven from the outside and capable of generating arbitrary pressing in the direction of the rotation axis of the kiln main body 31, and a sealing member 9 that makes one round of the outer peripheral surface, and A second seal ring 2 is provided which is mounted in the second groove 1 and is movable in the direction of the rotation axis of the kiln main body 31 by coming into contact with the pressurizing means.

Specifically, the pressurizing means includes a plurality of pistons 6 driven by the pressure of a gas or liquid such as nitrogen or water injected from a drive hole 11 penetrating the outside. As shown in FIG. 1, the piston 6 has a substantially cylindrical shape, and a seal groove is provided on the outer peripheral surface thereof, and an O-ring 8 made of a rubber member or the like is attached to the seal groove, thereby sealing the outside and the seal. Therefore, the gas or liquid does not enter the seal part or the furnace.

The first groove 3 and the second groove 1 are formed concentrically with an annular pressing plate 5, and a plurality of grooves are formed at the bottom of these grooves as shown in FIGS. 2 (a) and 2 (b). The piston 6 is installed such that its pushing surface is exposed at the bottom of the groove.

Further, as shown in FIG. 1, the first groove 3 and the second groove 1 are provided with a first seal ring 4 and a second seal ring having a cross-sectional shape substantially matching these groove cross sections. 2 is installed. In addition, seal grooves 10 and 10 are formed on the outer peripheral surfaces of these seal rings over the entire circumference, and seal members 9 and 9 made of a rubber member or the like are attached to these seal grooves.

The seal members 9 and 9 leak gas from the furnace through the gap between the first groove 3 and the first seal ring 4 and the gap between the second groove 1 and the second seal ring 2. Conversely, it is provided in order to prevent external air from entering the furnace.

With such a structure, by injecting a gas or liquid such as nitrogen or water from the drive hole 11, the plurality of pistons 6 can move in the direction of the rotation axis of the kiln body 31, that is, the direction of the disk plate 44. In addition, since it is pushed out with a substantially uniform pressure, the first seal ring 4 and the second seal ring 2 in contact therewith are also pushed in the direction of the disk plate 44 in the same manner. Accordingly, two seal surfaces are formed concentrically between the first seal ring 4 and the second seal ring 2 and the disk plate 44.

The surface pressure of these seal surfaces can be arbitrarily selected by controlling the pressure of the gas or liquid injected from the drive hole 11. However, if the surface pressure is increased, the seal ring will be worn more seriously. Therefore, it is better to select the optimum value. Further, specifically, the means for controlling the pressure of the gas or liquid can be easily realized by using a conventional technique such as a compressor or a pressure reducing valve.

The present invention further includes an introduction hole 12 for introducing a gas or liquid from the outside between the first groove 3 and the second groove 1, and means for injecting the gas or liquid into the introduction hole 12, Means for controlling the pressure of the gas or liquid injected into the introduction hole 12 is provided.

A plurality of the introduction holes 12 are provided between the first groove 3 and the second groove 1 as shown in FIG. Specifically, the means for injecting the gas or liquid and the means for controlling the pressure can be easily realized by using conventional techniques such as a compressor and a pressure reducing valve.

With this structure, a gas or liquid such as nitrogen or water injected from the introduction hole 12 fills the sealed space formed between the two seal surfaces. Therefore, by making the pressure of the gas or liquid larger than the pressure in the furnace, it is possible to completely prevent gas leakage from the inside of the furnace, or conversely, intrusion of external air into the furnace. The magnitude of the pressure of the gas or liquid is preferably larger than the pressure in the furnace as described above, and can be arbitrarily selected. However, if the pressure is too large, the gas or liquid passes through the two sealing surfaces. Leaking into and out of the furnace can cause problems. If the pressure is too small, the sealing performance is deteriorated, so it is preferable to select an optimum value.

Furthermore, the present invention further includes a means for detoxifying the atmosphere gas in the kiln body flowing out from the introduction hole 12 by making the internal pressure of the introduction hole 12 smaller than the internal pressure of the kiln body 31. It can also be. Specifically, the means for reducing the internal pressure of the introduction hole 12 to be smaller than the internal pressure of the kiln main body can be easily realized by using a conventional technique such as a vacuum pump or a pressure reducing valve. Specifically, it can be easily realized by using a conventional technique such as a chemical decomposition reaction using a catalyst or a dust collection filter.

With such a structure, the pressure in the sealed space formed between the two seal surfaces is also smaller than the internal pressure of the kiln body 31, so that the gas leaked from the inside of the kiln and the air entering from the outside are Both are absorbed and discharged from the introduction hole 12 and detoxified by the detoxifying means, thus completely preventing gas leakage from the inside of the furnace and conversely intrusion of external air into the furnace. It is also possible to prevent contamination. The size of the internal pressure of the introduction hole 12 needs to be smaller than the pressure in the furnace as described above, and can be arbitrarily selected. However, if it is too small, the amount of the gas absorbed and discharged from the introduction hole 12 is reduced. The amount increases, and it becomes necessary to increase the processing capacity of the means for detoxifying, and the manufacturing cost and the size of the equipment may be problematic. Further, if the pressure is not small enough, the sealing performance is deteriorated, so it is preferable to select an optimum value.

In addition to nitrogen and water, air, water vapor, and oils and fats may be used as the types of gases or liquids described so far. The selection criteria include the types and pressures of the atmosphere inside and outside the furnace, cost, and durability. Considering the ease of maintenance, etc., it is better to select the optimum.

As apparent from the above description, the seal structure of the rotary kiln according to the present invention is such that two seal portions are formed concentrically on the seal surface side of the annular presser plate 5, so that one conventional seal is used. Since double sealing performance is obtained compared to the sealing structure with only the part, and between the two sealing parts, gas or liquid such as nitrogen or water having a pressure higher than the furnace pressure is enclosed, It is possible to completely prevent gas leakage from the inside and, conversely, intrusion of outside air into the furnace, and a total of triple sealing performance can be obtained as compared with the conventional sealing structure.

In addition, since two seal portions are formed concentrically on the seal surface side of the annular pressing plate, double sealing performance can be obtained compared to a conventional seal structure using only one seal portion. If the internal pressure of the introduction hole is made smaller than the internal pressure of the kiln main body and the atmosphere gas in the kiln main body flowing out from the introduction hole is detoxified, Therefore, the gas leaking from the inside of the kiln and the air entering from the outside are both absorbed and discharged from the introduction hole and rendered harmless by the detoxifying means. Therefore, it is possible to completely prevent gas leakage from the inside of the furnace and, conversely, outside air from entering the furnace, resulting in a total triple sealing performance as compared with the conventional sealing structure, and the environment. It is possible to prevent the dyeing.

The surface pressure of the seal surface formed between the first and second seal rings installed on the two seal portions and the disk plate is determined by the rear portion of the first and second seal rings. For example, the piston driven from the outside installed in is obtained by pushing the first and second seal rings in the direction of the rotation axis of the kiln body, that is, in the direction of the disk plate. Therefore, by controlling the driving force of the piston from the outside, the surface pressure of the seal surface can be freely set, and a constantly stable surface pressure required for sealing can be obtained.

As a result, the sealing performance is greatly improved compared to the conventional sealing structure, and it is possible to completely prevent gas leakage from the inside and, on the contrary, the intrusion of external air into the furnace, and also prevent environmental pollution. It becomes.

Furthermore, a wide variety of materials can be selected as the material of the first and second seal rings, for example, by selecting carbon or steel material that is hard and has good slidability, compared to the rubber member of the conventional example, It is possible to dramatically improve the life of the seal ring. Thereby, the frequency | count of periodic replacement | exchange of a seal ring will decrease, and the sealing structure of a rotary kiln with easy maintenance can be provided.

In addition, if the piston is constituted by a plurality of pistons driven by the pressure of a gas or liquid such as nitrogen or water injected from a driving hole penetrating the outside and sealed from the outside, for example, Even when the wear of the second seal ring progresses and its thickness decreases, the plurality of pistons can always push the first and second seal rings in the direction of the disk plate with a constant pressure. . Therefore, it is possible to provide a rotary kiln seal structure that can prevent the seal performance from deteriorating even when the wear of the seal member proceeds.

Therefore, the present invention has a great industrial value as a seal structure of a rotary kiln that solves the conventional problems.

It is principal part sectional drawing which shows the seal structure of the rotary kiln in one Example of this invention. The connection part of the kiln main body and movable end side duct part in the said rotary kiln is shown, Comprising: The same figure (a) is sectional drawing, The same figure (b) is an AA arrow half view in the same figure (a). It is sectional drawing. It is a front view which shows the structure of the conventional rotary kiln. It is a principal part top view of the seal part in the rotary kiln shown in FIG. It is principal part sectional drawing of the seal part in the rotary kiln shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 2nd groove 2 2nd seal ring 3 1st groove 4 1st seal ring 5 Holding plate 6 Piston 7 Roller bracket 8 O-ring 9 Seal member 10 Seal groove 11 Drive hole 12 Introduction hole 31 Kiln main body 32 Tire Part 33 Sprocket 34 Entrance side hood part 35 Heating means 36 Exit side hood 37 Entrance side seal device 38 Exit side seal device 41 Frame body 42 Rail 43 Seal plate 44 Disc plate 45 Guide roller 46 Lip type seal material 47 Bellows

Claims (5)

A cylindrical kiln main body for transferring an object to be processed while rotating; a fixed hood provided at each end of the kiln main body; and an annular disk plate provided at at least one end of the kiln main body; An annular pressing plate connected to a corresponding fixed hood via a telescopic bellows, and means for fixing the pressing plate so as to be rotatable along the rotation direction of the disk plate, In a rotary kiln seal structure in which a slidable seal member is disposed between the presser plate and hermetically sealed, the seal plate side of the presser plate is driven externally and arbitrarily in the direction of the rotation axis of the kiln body. A first groove having a pressurizing means capable of generating the pressure and a seal member that makes one round of the outer peripheral surface, and is attached to the first groove and abuts on the pressurizing means. A first seal ring that is movable in the direction of the rotation axis of the kiln main body, a second groove that is driven from the outside and has a pressurizing means that can generate arbitrary pressing in the direction of the rotation axis of the kiln main body, A second seal ring having a seal member that makes one round of the outer peripheral surface, mounted in the first groove, and movable in the rotational axis direction of the kiln main body by contacting the pressurizing means; An introduction hole for introducing a gas or a liquid from the outside between the first groove and the second groove, a means for injecting the gas or the liquid into the introduction hole, and the pressure of the gas or the liquid injected into the introduction hole A rotary kiln seal structure characterized in that means for controlling the rotary kiln is provided. 2. The rotary kiln according to claim 1, wherein the pressurizing unit includes a plurality of pistons that are driven by a pressure of a gas or a liquid injected from a drive hole penetrating the outside and sealed from the outside. Seal structure. The rotary kiln seal structure according to claim 2, wherein the gas or liquid injected into the drive hole and the introduction hole is any one of air, nitrogen, water vapor, water, and oil. The gas or liquid injected into the drive hole is any one of air, nitrogen, water vapor, water, and oil and fat, the internal pressure of the introduction hole is made smaller than the internal pressure of the kiln body, and the gas flows out of the introduction hole The rotary kiln seal structure according to claim 2, further comprising means for detoxifying the atmosphere gas in the kiln main body. The rotary kiln seal structure according to any one of claims 1 to 4, wherein the first seal ring and the second seal ring are made of carbon or steel.

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