Patent Application
20250224178
The present invention relates to a sealing arrangement of a rotary kiln, which seals an outer periphery of a rotating part of the rotary kiln, and to a rotary kiln comprising a sealing arrangement according to the invention.
Rotary kilns are widely used in the process industry, for example in the chemical industry or the cement industry. In this case, there is the problem of sealing a rotating rotary tube with respect to the surroundings. For this purpose, a sealing arrangement is arranged on an outer periphery of the rotary tube. In order to ensure function of the rotary kiln without problem, very high requirements must be placed on the sealing arrangements. However, this makes the sealing arrangements relatively complex and expensive.
The object of the present invention is therefore that of providing a sealing arrangement of a rotary kiln, and a rotary kiln, which, with a simple design and simple, cost-effective manufacturability, allows for reliable operation of the rotary kiln over a long operating period.
This object is achieved by a sealing arrangement of a rotary kiln having the features of claim 1, and a rotary kiln having the features of claim 13. The dependent claims each show preferred developments of the invention.
The sealing arrangement of a rotary kiln according to the invention, for sealing a rotating component of the rotary kiln, in particular a rotary tube, having the features of claim 1, has the advantage that construction is very simple and therefore cost-effective. Furthermore, it is possible that identical parts can be used, as a result of which the costs for producing the sealing arrangement can be further reduced. Nonetheless, reliable sealing on a rotating part of the rotary kiln can be ensured, and thus a loss of energy and product to the atmosphere can be prevented. A further significant advantage of the sealing arrangement according to the invention is that relative movements both in the radial and in the axial direction can also be absorbed. This can take place during operation of the rotary kiln, on account of thermal influences during operation. This is achieved according to the invention in that the sealing arrangement comprises a first and a second seal half. The first seal half comprises a first sealing cord and a first retaining structure having a first and second lateral retaining ring element, wherein in each case one retaining ring element is arranged on an axial side of the first sealing cord. The second seal half comprises a second sealing cord and a second retaining structure having a first and second lateral retaining ring element, wherein the second sealing cord is arranged between the two retaining ring elements. Furthermore, a first and a second traction system are provided. The first traction system is configured to preload the first seal half by means of a tensile force F on the rotating component. The second traction system is configured to preload the second seal half by means of a tensile force F on the rotating component. The tensile forces of the first and second traction system are preferably of the same magnitude. Furthermore, the first and the second seal half of the sealing arrangement are arranged offset in the axial direction in such a way that a first and second axial overlap region results. At the overlap regions, the first and second sealing cords are guided side-by-side. In order to ensure sealing also in the axial direction, at the overlap region, the sealing arrangement further comprises a first and a second fixing element which fixes the first and second seal half at the overlap regions, in the axial direction.
Thus, the sealing arrangement provides sealing in the radial direction on a rotary tube, on the outer periphery of the rotary tube, and additionally provides axial sealing at the two overlap regions. Thus, the rotary tube, which rotates during operation of the rotary kiln, can be reliably sealed with respect to stationary components of the rotary kiln. In this case, the first and second sealing cord wrap around the rotary tube on the outer periphery, wherein each sealing cord preferably seals a sealing region on the rotary tube of 180° in the radial direction. Furthermore, the first and second traction system are preferably configured identically. This allows for a reduction in the complexity of the sealing arrangement by the plurality of identical parts.
Preferably, the overlap regions of the two seal halves are opposite one another.
Further preferably, the sealing arrangement further comprises contact sealing rings which are arranged axially between the sealing cords and the retaining structures. The contact sealing rings are thus in direct contact with the sealing cords. The contact sealing rings are preferably metal, in particular produced from bronze, brass or PTFE. In this case, the contact sealing rings are preferably arranged such that the sealing cords protrude slightly beyond the contact sealing rings towards the inside in the radial direction. Sealing of the rotary tube on the outer periphery thus takes place by the contact between the rotary tube and the sealing cords. Should wear occur on the sealing cords, the contact sealing rings additionally come into contact with the outer periphery of the rotary kiln. In this case, the sealing cords can now be replaced, or alternatively the rotary kiln is operated further, such that the contact sealing rings which are now, together with the sealing cords, in contact with the outer periphery of the rotary tube, also wear. After a certain operating time, then, in addition to the sealing cords, the contact sealing rings must also be replaced.
The contact sealing rings are preferably rigidly connected to the sealing cords, for example by pins which are guided through the sealing cords.
In order to ensure a structure that is as simple as possible, the contact sealing rings are preferably constructed from a plurality of ring segments. The ring segments are preferably configured identically, and preferably comprise a curved projection in the peripheral direction, at one end, and a curved recess, configured in a manner corresponding to the curved projection, at the other end.
The traction systems preferably each comprise a fixed bearing at one end of the sealing cords and a traction device at the other end of the sealing cords. As a result, a particularly simple and cost-effective structure can be achieved. Alternatively, the traction systems each comprise traction devices at both ends of the sealing cords.
The traction devices preferably each comprise a compression spring, e.g. a cylinder spring or leaf spring, which is configured to exert the tensile force F on the sealing cords. In this case, the compression spring is preferably arranged between a stationary support and a nut that is connected to the tension rod. The tension rod preferably comprises a thread, such that the preload can be set by twisting the nut on the threaded rod, which is connected to a sealing cord.
In order to allow for the simplest possible fixing at the overlap regions, the first and second fixing elements each comprise two plates, which are detachably interconnected. The plates can be interconnected for example by screws or the like. The plates are particularly preferably part of a housing of the sealing arrangement.
For improved absorption of axial movements of the rotary tube, the sealing arrangement further preferably comprises preload elements which exert a preload on the first and second seal half, in the axial direction.
Further preferably, support elements are arranged on the outer periphery of the first and second sealing cords, which support elements prevent a relative movement between the two sealing cords and the contact elements. The support elements are preferably pins, which are preferably fixed to the retaining ring elements of the retaining structures. Thus, the sealing cords and the contact elements follow radial movements of the pressure pipe together, if the pressure pipe performs such radial movements during operation.
Further preferably, the sealing arrangement comprises support arms, on which the traction systems are arranged. The support arms are particularly preferably part of a housing of the sealing arrangement.
In order to be able to measure wear of the sealing arrangement, the two traction systems preferably comprise wear indicators. These wear indicators can for example be measuring scales, which are arranged on the tension rod of the traction systems.
The present invention further relates to a rotary kiln comprising a rotary tube and a sealing arrangement according to the invention.
Preferred embodiments of the invention are described in detail in the following with reference to the accompanying drawings, in which:
A sealing arrangement 1 according to a preferred embodiment of the invention is described in detail in the following, with reference to
The sealing arrangement 1 is arranged in a stationary manner and does not rotate with the rotary tube 101.
The sealing arrangement 1 for sealing on the rotary tube 101 comprises a first seal half 10 and a second seal half 20. The two seal halves 10, 20 are configured to be substantially identical. In this case, the two seal halves are point-reflected at a centre M of the sealing arrangement. A central axis X-X extends through the centre M, in the axial direction of the sealing arrangement.
The first seal half 10 comprises a first sealing cord 11 and a first retaining structure 12. In this case, the first retaining structure 12 comprises a first retaining ring element 13 and a second retaining ring element 14.
The second seal half 20 is configured identically to the first seal half 10 and comprises a second sealing cord 21 and a second retaining structure 22. The second retaining structure 22 also comprises a first and second retaining ring element 23, 24. In each case one retaining ring element 23, 24 is arranged on an axial side of the second sealing cord 21.
The sealing arrangement 1 further comprises a first traction system 3 and a second traction system 4. The two traction systems 3, 4 are configured to exert a tensile force F on the first and second sealing cord 11, 21. Thus, the two traction systems 3, 4 preload the two sealing cords 11, 21 radially on the rotary tube 101, in order to provide a sealing effect on the outer periphery of the rotary tube. In this case, the sealing effect is provided both in the case of a stationary and in the case of a rotating rotary tube 101.
Furthermore, the first and the second seal half 10, 20 are arranged offset in the axial direction of the sealing arrangement, in such a way that a first overlap region 5 and a second axial overlap region 6 results. The offset arrangement of the two sealing cords 11, 21 thus allows for radial sealing on the inside periphery of the sealing cords, on the rotary tube, and also axial sealing between the two sealing cords 11, 21, at the two overlap regions. This is shown in particular in
In order to ensure the axial sealing at the two overlap regions 5, 6, the sealing arrangement further comprises a first fixing element 901 on the first overlap region 5 and a second fixing element 902 on the second overlap region 6. The two fixing elements 901, 902 fix the two seal halves 10, 20, and are configured to be U-shaped in cross-section, such that the first and second sealing cords are held in the axial direction.
The first retaining structure 12 and the second retaining structure 22 thus form an annular frame, wherein the sealing cords 11, 21 are arranged between the retaining ring elements 13, 14 and 23, 24. The retaining ring elements can preferably be part of a housing 9.
The fixing elements 901, 902 can also be part of the housing 9 of the sealing arrangement 1.
The sealing arrangement 1 furthermore also comprises a first and second contact sealing ring 7, 8 on each seal half 10, 20. As can be seen in particular from
The ring segments 70, 80 are visible in detail from
As is visible in particular from
In order to prevent a relative movement of the first and second sealing cord 11, 21 and the contact sealing rings 7, 8, in the radial direction, a plurality of support elements 51 in the form of small pins is provided. The pins are preferably in each case arranged between the first and second contact sealing ring 7, 8 (cf.
Furthermore, a plurality of axial preload elements 50 is also arranged along the periphery, which elements exert an axial force on the outer contact sealing rings.
Thus, during operation of the rotary tube, firstly the sealing cords 11, 21 come into direct sealing contact with the outer periphery of the rotary tube. If, after a certain time, wear occurs on the inner surfaces of the sealing cords 11, 21, the edge regions of the first and second contact sealing rings 7, 8 of the two seal halves 10, 20 also come into contact with the outer periphery of the rotary tube. A user of the sealing arrangement according to the invention can then decide whether they wish to only exchange the sealing cords 11, 21 or to continue to operate the rotary kiln, such that wear also occurs at the inside edges of the first and second contact sealing rings 7, 8. Thus, if the rotary kiln is operated further, in addition to the sealing at the inside periphery of the sealing cords 11, 21, further sealing also takes place at the edges of the first and second contact sealing rings 7, 8.
During further operation of the rotary kiln, the inner surfaces of the sealing cords 11, 21 and the inside edges of the contact sealing rings 7, 8 then wear together. After a certain degree of wear, the sealing cords and the contact sealing rings must then be replaced together.
As can be seen from the schematic view of
The first and second traction device 31, 41 are configured identically.
Preferably a wear indicator 15, for example a scale (not shown in detail) is additionally also arranged on the traction device, by means of which wear of the sealing arrangement can be displayed, since in the case of wear on the components in contact with the rotary tube the position of the tension rod 43 changes on account of the compression spring 42.
The first traction device 31, which is arranged diametrically opposite the second traction device 41 (cf.
For connection between the first traction device 31 and the first sealing cord 11, a connecting piece 36 is provided (cf.
As can be seen schematically from
However, as can be seen from a comparison of
Thus, the sealing arrangement 1 according to the invention can enable reliable sealing on a rotating rotary tube 101 of a rotary kiln 100. In principle, in this case, sealing can also take place in both directions of rotation of the rotary tube 101, without additional leaks or the like resulting. The performance of the seal is identical in both directions of rotation. In order to stiffen the sealing arrangement, furthermore a plurality of cross members or flanges or the like can be provided on the housing. In the case of wear having occurred, in the case of the sealing arrangement according to the invention actually only the sealing cords 11, 21 and possibly the contact sealing rings 7, 8 have to be replaced. In this case, the traction systems 3, 4 and the further components of the sealing arrangement 1 can be reused.
The axially offset arrangement of the first and second sealing cord 11, 21 also enables radial sealing on the entire periphery of the rotary tube. In addition, axial sealing also takes place at the two transition regions 5, 6, which sealing is maintained by the first and second fixing elements 901, 902. Wear of the sealing arrangement can furthermore be easily read off on the traction systems 3, 4 located outside the housing, for example on a scale.
In addition to the above written description of the invention, for the additional disclosure thereof reference is hereby explicitly made to the illustrative drawings of the invention in
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2022 109 305.0 | Apr 2022 | DE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2023/052994 | 2/7/2023 | WO |
