Rotary sealing device and method for furnace body and rotary furnace

Abstract

The invention belongs to the technical field of rotary furnaces, and particularly relates to a furnace body rotary sealing device and method and a rotary furnace. The furnace body rotary sealing device comprises a furnace body (10); an annular gap (30) is formed at the overlapped part of the furnace body (10) and the furnace end (20); the primary axial sealing element (40) is clamped in the annular gap (30) in a spiral winding shape and can push smoke accumulated in the annular gap (30) back into the furnace end (20) along with rotation of the furnace body (10); the secondary axial sealing element (50) comprises a fixed ring (51) and a sealing gasket (52), and the sealing gasket (52) is tensioned on the axial outer circumferential surface of the fixed ring (51); and the sealing cavity (60) is formed between the primary axial sealing element (40) and the secondary axial sealing element (50). The combination of axial sealing and radial sealing is replaced by secondary axial sealing, meanwhile, the structures and the mounting positions of the primary axial sealing piece and the secondary axial sealing piece are innovated, and the sealing effect is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of rotary kilns, and particularly relates to a furnace body rotary sealing device, method and rotary kiln. Background Art

[0002] A rotary kiln is a commonly used pyrolysis furnace, and its main structure includes a furnace body and a furnace head. The furnace heads are located at both ends of the furnace body and are used to provide support for the furnace body. The furnace body is driven by a transmission mechanism to rotate. To prevent the gas in the furnace body from leaking from the connection between the furnace head and the furnace body, a furnace body rotary sealing device needs to be provided at the connection between the furnace head and the furnace body.

[0003] The applicant has developed two modes of furnace body rotary sealing devices. One is as described in the patent document CN104728448A, including: a furnace body and a furnace head. The end of the furnace head wraps the end of the furnace body. To prevent gas leakage at the connection between the furnace body and the furnace head, a receiving block for sealing is provided at the end of the furnace head, and a pressing block with a pressing mechanism is provided at the end of the furnace body. The pressing block is L-shaped. A gas radial seal is formed between the side surface of the pressing block and the receiving block of the furnace head by setting a sealing strip, and a gas axial seal is formed between the bottom surface of the pressing block and the surface of the furnace body by setting a sealing strip. During use, the applicant found that since there is no pressing mechanism between the bottom surface of the pressing block and the surface of the furnace body, after the sealing strip between the bottom surface of the pressing block and the surface of the furnace body is worn, it is easy to cause gas leakage. Secondly, the pressing mechanism is only provided at the outer edge of the pressing block, making the sealing strip unevenly stressed between the receiving block and the pressing block, and it is easy to cause different degrees of wear and gas leakage.

[0004] Another patent document CN110762216A discloses the applicant's second-generation furnace body rotary sealing technology. The connection method between the furnace body and the furnace head is changed to that the end of the furnace body wraps the end of the furnace head. The fixed ring (i.e., the receiving block in CN104728448A) is provided on the furnace body and rotates with the rotation of the furnace body. There are clamping pieces A and clamping pieces B on both sides of the fixed ring. The upper sealing strips on the clamping pieces A and clamping pieces B are closely attached to the two side surfaces of the fixed ring, achieving multi-stage sealing in the radial direction. In the axial sealing, the contact surface between the lower sealing strip at the bottom of the clamping piece B and the furnace head does not rub, so there is no wear on this contact surface, thus ensuring the axial sealing effect and overcoming the drawbacks of the first-generation sealing technology. Moreover, the leaked gas must first pass through the axial sealing part before entering the radial sealing part, greatly improving the sealing effect. The disadvantages of this solution are: (1) The precision requirements for both sides of the fixed ring are relatively high. Otherwise, the sealing strips cooperating with different positions on its side surface will still have different degrees of wear; (2) The structure is relatively complex and the installation is cumbersome, especially the installation of the radial sealing structure, which is time-consuming and laborious; (3) When gas leakage occurs due to aging of the lower sealing strip, dust accumulates in the space between the fixed ring and the clamping piece and cannot be cleaned, resulting in increased wear of the upper sealing strip. Summary of the Invention

[0005] The object of the present invention is to overcome the deficiencies of the prior art and provide a new type of rotary seal device for a furnace body, which can achieve a good rotary seal effect only with axial sealing, and at the same time improve the simplicity of installation and maintenance of the rotary seal device.

[0006] The solution of the present invention to solve the above technical problems is as follows: The rotary seal device for a furnace body includes a furnace body, which is provided with a driving mechanism so that it can rotate; a furnace head, which is used to provide end support for the furnace body, is nested with the furnace body, and forms an annular gap at the overlapping part of the furnace body and the furnace head; a primary axial seal, which is spirally wound and clamped in the annular gap, and is fixed to the furnace body or the furnace head, so that it can push the soot accumulated in the annular gap back into the furnace head as the furnace body rotates; a secondary axial seal, which includes a fixed ring and a sealing gasket. The fixed ring is fixed to the end of the furnace body or the furnace head, and the sealing gasket is tensioned on the outer circumferential surface of the axial direction of the fixed ring; a sealing cavity, which is formed between the primary axial seal and the secondary axial seal, is used to prevent the soot entering the sealing cavity through the primary axial seal from directly impacting the secondary axial seal, and provides a temporary storage space for the soot.

[0007] The inventive concept of the present invention is: changing the sealing technology mainly based on radial sealing in the previous two generations, and taking the axial sealing as the key improvement direction based on the simplicity of installation and maintenance of the axial sealing structure, so that it still has a good rotary seal effect without setting a radial sealing structure. That is: using a secondary axial seal to replace the combination of axial seal and radial seal. Of course, if a radial sealing structure is added, the sealing effect will surely be further enhanced. The main innovative technical features of this application are as follows: First, the primary axial seal is arranged in the annular gap. In addition to playing a role in blocking soot, it can also push the soot accumulated in the annular gap back into the furnace head as the furnace body rotates, reducing the probability of soot entering the sealing cavity. Second, a secondary axial seal is added. The sealing gasket of the secondary axial seal is tensioned on the outer circumferential surface of the axial direction of the fixed ring. Not only is it convenient to install, but also because the sealing gasket is tensioned on the outer circumferential surface of the axial direction of the fixed ring, even if there are different degrees of wear between the sealing gasket and the outer circumferential surface of the axial direction of the fixed ring, gas is not easily leaked, because the outer circumferential surface of the fixed ring is wrapped by the sealing gasket, and the inner side and the outer side of the fixed ring are always pressed by the tensioned sealing gasket.

[0008] In one embodiment, one end of the furnace body is nested in the end of the furnace head, and the annular gap is formed outside the outer circumferential surface of the axial direction of the furnace body. Obviously, the connection method of the furnace body and the furnace head can also be that one end of the furnace head is nested in the end of the furnace body.

[0009] In one embodiment, the primary axial seal is a helical wire, and both ends of the wire extend to both ends of the annular gap. When the helical wire rotates, it can push the soot entering the annular gap back.

[0010] In one embodiment, the gasket is provided with a gasket support frame; when the fixed ring is fixed to the furnace body, the gasket support frame is fixed to the furnace head; the gasket support frame has end fixing members for tensioning and fixing both ends of the gasket. After the end fixing members of the gasket support frame pull the gasket apart, it is buckled on the outer circumferential surface of the axial direction of the fixed ring.

[0011] In one embodiment, the gasket is provided with a pressing member for pressing the gasket against the outer circumferential surface of the axial direction of the fixed ring, and the pressing member includes a hoop for clamping the gasket to the outer circumferential surface of the axial direction of the fixed ring; the two connection ends of the hoop are elastically connected; a hoop positioning member located on the outer surface of the hoop for axial positioning of the hoop.

[0012] In one embodiment, the hoop positioning member is provided with a guiding hole, so that the hoop has a position adjustment space in the axial and radial directions. When the furnace body rotates, there will inevitably be a small amount of axial movement. The guiding hole provided on the hoop positioning member can avoid the adverse effects on the pressing member caused by the axial movement of the furnace body.

[0013] In one embodiment, the width of the outer circumferential surface of the axial direction of the fixed ring is not less than 40 mm, and the width of the gasket is not less than 100 mm. The larger the width of the outer circumferential surface of the axial direction, the better the sealing effect.

[0014] In one embodiment, the primary axial seal and the secondary axial seal are located on the same side of the sealing cavity. The gasket is provided with a gasket support frame, and the gasket support frame is provided with end fixing members for fixing the gasket. The end fixing members are located on the side of the sealing cavity and protrude from the surface of the sealing cavity in the axial direction. Since the end fixing members protrude from the surface of the sealing cavity, the soot entering the sealing cavity is easily blocked by the end fixing members, reducing the probability of the soot contacting the secondary axial seal, which is beneficial to improving the sealing effect.

[0015] The present application also provides a method for rotating and sealing a furnace body, including the following steps, (1) Primary axial sealing: A helically wound body is clamped in the annular gap formed at the overlapping part of the furnace body and the furnace head, so that the helically wound body can push the soot accumulated in the annular gap back into the furnace head as the furnace body rotates; (2) Secondary axial sealing: A fixed ring is provided at the end of the furnace body or the furnace head, and the outer circumferential surface of the axial direction of the fixed ring is covered by a gasket, and the gasket is tensioned on the outer circumferential surface of the axial direction of the fixed ring; (3) A sealed space is formed between the first-stage axial seal and the second-stage axial seal to prevent the soot entering the sealed space via the first-stage axial seal from directly impacting the second-stage axial seal. The soot entering the sealed space needs to pass through the outer circumferential surface of the fixed ring shaft covered by the gasket before leaking to the outside.

[0016] This application also discloses a rotary kiln, which includes A furnace body equipped with a driving mechanism to enable it to rotate; A furnace head for providing end support for the furnace body, nested with the furnace body, and forming an annular gap at the overlapping part of the furnace body and the furnace head; A first-stage axial seal, spirally wound and clamped in the annular gap, and fixed to the furnace body or the furnace head, so that it can push the soot accumulated in the annular gap back into the furnace head as the furnace body rotates; A second-stage axial seal, including a fixed ring and a gasket. The fixed ring is fixed to the end of the furnace body or the furnace head, and the gasket is tensioned on the outer circumferential surface of the fixed ring; A sealed cavity is formed between the first-stage axial seal and the second-stage axial seal, and is used to provide a temporary storage space for the soot passing through the first-stage axial seal; A gas treatment system; A heating system.

[0017] In summary, the present invention replaces the combination of axial seal and radial seal with a second-stage axial seal, and at the same time innovates the structures and installation positions of the first-stage axial seal and the second-stage axial seal, which is beneficial to improving the sealing effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is a schematic structural diagram of the present invention; Figure 2 is Figure 1 the sectional view taken along the A-A direction in Figure 3 is Figure 2 the enlarged view of part B in Figure 4 is a diagram showing the positional relationship between the first-stage axial seal of the present invention and the furnace body; Figure 5 is Figure 4 the enlarged view of part C in Figure 6 is Figure 5 the enlarged view of part D in Figure 7 is a schematic structural diagram of another perspective of the present invention; Figure 8 is Figure 7 the enlarged view of part E in Figure 9 is Figure 7 the enlarged view of part F in Figure 10 It is a cross-sectional view of the primary axial seal and the secondary axial seal in Example 2.

[0019] In the figure: 10, furnace body; 11, heat insulation layer; 20, furnace head; 30, annular gap; 40, primary axial seal; 50, secondary axial seal; 51, fixing ring; 52, gasket; 53, gasket support frame; 54, end fixing member; 55, pressing member; 551, hoop; 552, gasket; 553, guiding hole; 60, sealing cavity. Embodiment

[0020] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms also fall within the scope defined by the appended claims of this application. Example

[0021] The furnace body rotary sealing device described in this application is used for the rotary sealing of the furnace body 10 and the furnace head 20 in a converter. Among them, the furnace body 10 is provided with a driving mechanism so that it can rotate, and the furnace head 20 is fixed at both ends of the furnace body 10 and is used to provide end support for the furnace body 10. The furnace body 10 and the furnace head 20 are nested and connected. In this embodiment, the furnace body 10 is nested inside the furnace head 20, and an annular gap 30 is formed at the overlapping part of the furnace body 10 and the furnace head 20. The annular gap 30 is formed outside the axial outer circumferential surface of the furnace body 10. Specifically, as Figures 1-3 shown.

[0022] As Figure 3 , Figure 4 shown, a primary axial seal 40 is arranged in the annular gap 30. It is a spiral metal wire, and both ends of the metal wire extend to both ends of the annular gap 30 respectively. The primary axial seal 40 is wound and fixed on the outer wall of the furnace body 10, and can push the soot accumulated in the annular gap 30 back into the furnace head 20 as the furnace body 10 rotates. Among them, Figure 4 the heat insulation layer 11 of the furnace body 10 is not shown.

[0023] As Figure 3 , Figure 5As shown, a secondary axial seal 50 is provided outside the annular gap 30. The secondary axial seal 50 includes a fixed ring 51 and a gasket 52. The fixed ring 51 is fixed to the end of the furnace body 10 and is a metal ring. Since the side surface of the fixed ring 51 is not used for sealing, different from CN104728448A and CN110762216A, the radial width of the fixed ring 51 does not need to be too large. In this embodiment, the radial width of the fixed ring 51 is 80 mm. To ensure the effect of the secondary axial seal, the axial width of the fixed ring 51 (i.e., the width of the outer circumferential surface in the axial direction) is 40 mm. Obviously, as the width of the outer circumferential surface in the axial direction increases, the secondary axial seal effect can be correspondingly improved.

[0024] The gasket 52 is made of flexible graphite gasket, and the width of the gasket is 100 mm. The gasket 52 is tensioned on the outer circumferential surface of the fixed ring 51 in the axial direction, and a sealing cavity 60 is formed between the primary axial seal 40 and the secondary axial seal 50. The sealing cavity 60 can prevent the soot entering the sealing cavity 60 through the primary axial seal 40 from directly impacting the secondary axial seal 50 and provide a temporary storage space for the soot.

[0025] The gasket 52 is provided with a gasket support frame 53, and the gasket support frame 53 is fixed to the furnace head 20. As Figures 5-8 shown, for convenient installation, the gasket support frame 53 adopts a two-piece structure and is fixed in the middle by a screw. The gasket support frame 53 has an end fixing member 54 for tensioning and fixing both ends of the gasket 52. There are 2 groups of end fixing members 54. The inner end fixing member 54 is a metal ring for fixing one end of the gasket 52 to the furnace head 20. The outer end fixing member 54 is several metal clips. The top of the metal clip is fixed to the gasket support frame 53, and the metal clip is used to clamp the outer edge of the gasket 52 to realize the fixation of both sides of the gasket 52.

[0026] The gasket 52 is provided with a pressing member 55 for pressing the gasket 52 onto the outer circumferential surface of the fixed ring 51 in the axial direction. The pressing member 55 includes a hoop 551 and a hoop positioning member 552. As Figure 7 、 Figure 9 shown, the hoop 551 is used to hoop the gasket 52 onto the outer circumferential surface of the fixed ring 51 in the axial direction. Springs are provided on the bolts at the two connection ends of the hoop 551, so that the two connection ends are elastically connected. As Figure 6 、 Figure 8 shown, the hoop positioning member 552 is located on the outer surface of the hoop 551 and is mainly used for the axial positioning of the hoop 551 to prevent the hoop 551 from disengaging from the tight hoop of the fixed ring 51 and the gasket 52 during operation. A guide hole 553 is provided on the hoop positioning member 552, and there is a pin shaft inside, so that the hoop 551 has a position adjustment space in the axial and radial directions.

[0027] It should be noted that: The present application does not exclude radial sealing. For example, in Figure 3 a transverse partition may be provided in the sealing cavity 60 as shown, which can reduce the probability of the soot entering the sealing cavity 60 from contacting the secondary axial seal 50. Embodiment

[0028] For example, Figure 10 as shown, in this embodiment, one end of the furnace body 10 is still nested inside the end of the furnace head 20, but the fixing ring 51 is fixed to the end of the furnace head 20, and the gasket support frame 53 is welded to the end of the furnace body 10 in a barrel shape. At this time, the radial width of the fixing ring 51 can be further reduced to at least 10 mm.

[0029] The primary axial seal 40 and the secondary axial seal 50 are located on the same side of the sealing cavity 60. An end fixing member 54 for fixing the gasket 52 is provided on the gasket support frame 53. The end fixing member 54 is located on the side of the sealing cavity 60 and protrudes from the surface of the sealing cavity 60 in the axial direction.

[0030] The advantage of Embodiment 2 compared with Embodiment 1 is that: it reduces the probability of the soot entering the sealing cavity 60 from contacting the secondary axial seal 50.

[0031] Obviously, when the furnace head 20 is nested inside the furnace body 10, those skilled in the art can make adaptive modifications to the rotary sealing device described in the present application. Embodiment

[0032] Embodiment 3 discloses a method for rotary sealing of a furnace body, including the following steps, (1) Primary axial sealing: A helically wound body is clamped in the annular gap formed at the overlapping part of the furnace body and the furnace head, so that the helically wound body can push the soot accumulated in the annular gap back into the furnace head as the furnace body rotates, and both ends of the helically wound body extend to both ends of the annular gap; (2) Secondary axial sealing: A fixing ring is provided around the end of the furnace body or the furnace head, and the outer circumferential surface of the fixing ring in the axial direction is covered by a gasket, and the gasket is tensioned on the outer circumferential surface of the fixing ring in the axial direction; (3) A sealing space is formed between the primary axial sealing part and the secondary axial sealing part to prevent the soot entering the sealing space through the primary axial sealing part from directly impacting the secondary axial sealing part. The soot entering the sealing space needs to pass through the outer circumferential surface of the fixing ring in the axial direction covered by the gasket before it can leak to the outside.

[0033] Obviously, Embodiments 1-2 only give two preferred structures for implementing this method, and those skilled in the art can also design other structures for implementing this method according to the guidance of this method. Embodiment

[0034] Example 4 is a rotary furnace, which includes a furnace body 10, a furnace head 20, a gas treatment system, and a heating system. Among them, the rotary sealing device between the furnace body 10 and the furnace head 20 is as described in Example 1 or Example 2.

Claims

1. Rotary sealing device for furnace body Characterized in that: Comprising Furnace body (10), equipped with a driving mechanism to enable it to rotate; Furnace head (20), used to provide end support for the furnace body (10), nestedly connected with the furnace body (10), and forming an annular gap (30) at the overlapping part of the furnace body (10) and the furnace head (20); Primary axial seal (40), spirally wound and clamped in the annular gap (30), and fixed to the furnace body (10) or the furnace head (20), so that it can push the soot accumulated in the annular gap (30) back into the furnace head (20) as the furnace body (10) rotates; Secondary axial seal (50), including a fixing ring (51) and a sealing gasket (52), the fixing ring (51) is fixed to the end of the furnace body (10) or the furnace head (20), and the sealing gasket (52) is tensioned on the outer circumferential surface of the fixing ring (51) in the axial direction; Sealing cavity (60), formed between the primary axial seal (40) and the secondary axial seal (50), used to prevent the soot entering the sealing cavity (60) via the primary axial seal (40) from directly impacting the secondary axial seal (50), and providing a temporary storage space for the soot.

2. The rotary sealing device for furnace body according to claim 1, Characterized in that: One end of the furnace body (10) is nested inside the end of the furnace head (20), and the annular gap (30) is formed outside the outer circumferential surface of the furnace body (10) in the axial direction.

3. The rotary sealing device for furnace body according to claim 1, Characterized in that: The primary axial seal (40) is a helical metal wire, and both ends of the metal wire extend to both ends of the annular gap (30).

4. The rotary sealing device for furnace body according to claim 1, Characterized in that: The sealing gasket (52) is provided with a sealing gasket support frame (53); when the fixing ring (51) is fixed to the furnace body (10), the sealing gasket support frame (53) is fixed to the furnace head (20); the sealing gasket support frame (53) has an end fixing member (54) for tensioning and fixing both ends of the sealing gasket (52).

5. The rotary sealing device for furnace body according to claim 1 or 4, Characterized in that: The sealing gasket (52) is provided with a pressing member (55) for pressing the sealing gasket (52) against the outer circumferential surface of the fixing ring (51) in the axial direction.

6. The rotary sealing device for furnace body according to claim 5, Characterized in that: The pressing member (55) includes A hoop (551) for clamping the sealing gasket (52) to the outer circumferential surface of the fixing ring (51); the two connection ends of the hoop (551) are elastically connected; A hoop positioning member (552), located on the outer surface of the hoop (551), for axially positioning the hoop (551).

7. The rotary sealing device for furnace body according to claim 6, Characterized in that: The hoop positioning member (552) is provided with a guiding hole (553), so that the hoop (551) has a position adjustment space in the axial and radial directions.

8. The rotary sealing device for furnace body according to claim 1, Characterized in that: The width of the axial outer circumferential surface of the fixed ring (51) is not less than 40 mm, and the width of the gasket (52) is not less than 100 mm.

9. The rotary sealing device for a furnace body according to claim 1, characterized in that: The primary axial seal (40) and the secondary axial seal (50) are located on the same side of the sealing cavity (60). The gasket (52) is provided with a gasket support frame (53). An end fixing member (54) for fixing the gasket (52) is provided on the gasket support frame (53). The end fixing member (54) is located on the side of the sealing cavity (60) and protrudes axially from the surface of the sealing cavity (60).

10. A method for rotary sealing of a furnace body, characterized in that: It includes the following steps, (1) Primary axial sealing: A helically wound body is clamped in the annular gap formed at the overlapping part of the furnace body and the furnace head, so that the helically wound body can push the soot accumulated in the annular gap back into the furnace head as the furnace body rotates; (2) Secondary axial sealing: A fixed ring is provided at the end of the furnace body or the furnace head. The axial outer circumferential surface of the fixed ring is covered by a gasket, and the gasket is tensioned on the axial outer circumferential surface of the fixed ring; (3) A sealing space is formed between the primary axial sealing part and the secondary axial sealing part to prevent the soot entering the sealing space through the primary axial sealing part from directly impacting the secondary axial sealing part. The soot entering the sealing space needs to pass through the axial outer circumferential surface of the fixed ring covered by the gasket before it can leak to the outside.

11. A rotary furnace, characterized in that: It includes a furnace body (10) equipped with a driving mechanism to enable it to rotate; a furnace head (20) for providing end support for the furnace body (10), nested with the furnace body (10), and forming an annular gap (30) at the overlapping part of the furnace body (10) and the furnace head (20); a primary axial seal (40) in a helically wound shape clamped in the annular gap (30) and fixed to the furnace body (10) or the furnace head (20), so that it can push the soot accumulated in the annular gap (30) back into the furnace head (20) as the furnace body (10) rotates; a secondary axial seal (50) including a fixed ring (51) and a gasket (52). The fixed ring (51) is fixed to the end of the furnace body (10) or the furnace head (20), and the gasket (52) is tensioned on the axial outer circumferential surface of the fixed ring (51); a sealing cavity (60) formed between the primary axial seal (40) and the secondary axial seal (50) for providing a temporary storage space for the soot passing through the primary axial seal (40); a gas treatment system; a heating system.

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