A furnace tube lagging

Abstract

This invention discloses a furnace tube insulation sleeve. The furnace tube insulation sleeve includes two semi-annular insulation sleeves. The cross-section of the semi-annular insulation sleeve is hollow and includes an elastic frame, an insulation layer, an inner protective film, and an outer protective film. The elastic frame is formed by interlocking an upper diaphragm spring and a lower diaphragm spring. Each of the upper and lower diaphragm springs includes a semi-circular disc, multiple separating fingers, a self-locking hole, and a self-locking buckle. The semi-circular disc is a planar semi-circular ring, and the separating fingers are conical surfaces with radial slots between adjacent separating fingers. The bottom ends of the separating fingers are evenly distributed on the inner ring of the semi-circular disc and integrally formed with the semi-circular disc. The top ends of the separating fingers are semi-arc tips. The separating fingers of the upper diaphragm spring protrude upwards, and the separating fingers of the lower diaphragm spring are concave downwards. The semi-arc tips of the upper diaphragm spring bend downwards, and the semi-arc tips of the lower diaphragm spring bend upwards. The two semi-annular insulation sleeves are joined together through the self-locking hole and the self-locking buckle to form a complete furnace tube insulation sleeve. Using this invention can solve the problem that in the prior art, the dynamic insulation of the insulation jacket only passively expands and contracts with the furnace tube, without elastically expanding and contracting with the thermal expansion and contraction of the furnace tube, thus making the dynamic insulation effect of the furnace tube better.

Description

Technical Field

[0001] This invention belongs to the technical field of converter furnaces in hydrocarbon steam reforming devices, and relates to a furnace tube insulation sleeve that can freely expand and contract with the thermal expansion and contraction of the furnace tubes. Background Technology

[0002] In hydrocarbon steam reforming units, such as the first-stage reformer in ammonia synthesis, methanol production, and hydrogen production, the reformer tubes are typically supported by an overhead suspension structure. This means the reformer tubes extend beyond the furnace roof and are suspended from a crossbeam at the top of the roof by spring hangers or pulley systems. During operation, the tubes expand upwards due to heat, and this expansion is absorbed by the spring hangers or pulley systems. As the tube temperature rises, the length of the tube extending beyond the roof increases by 0–300 mm. The tube wall temperature is very high, resulting in significant heat dissipation, thus requiring thermal insulation. However, static insulation cannot meet the dynamic insulation requirements due to the thermal expansion and contraction of the tubes, and existing dynamic insulation technologies also have limitations.

[0003] Chinese patent CN201827600U proposes an insulation sleeve, characterized in that the insulation sleeve is composed of an upper connector, a straight pipe insulation section, at least one corrugated flexible insulation section, and a lower connector. The straight pipe insulation section is above the corrugated flexible insulation section. The insulation sleeve can freely expand and contract with the thermal expansion and contraction of the furnace tube. Dynamic insulation of the furnace tube is achieved by multiple flexible insulation corrugations moving with the furnace tube.

[0004] Chinese patent CN201047481Y proposes a high-temperature furnace tube anti-radiation energy-saving heat insulation skirt, characterized in that it includes a skirt (2), a clamp (3) and a quick buckle (1). The clamp (3) is set at the upper end of the skirt (2), and the quick buckle (1) is set at the lower end of the skirt (2). The heat insulation skirt achieves dynamic heat insulation of the furnace tube by moving with the furnace tube.

[0005] Chinese patent CN200720076300.3 proposes a high-temperature fiber sealing device for a heating furnace tube. The sealing device is a bag made of a hot surface material layer and a cold surface material layer. The bag is filled with high-temperature fiber cotton. One end of the bag is fixed to the heating furnace tube, and the other end is fixed to the furnace top plate. The sealing device moves with the furnace tube, and it achieves dynamic heat preservation of the furnace tube by moving the bag with the furnace tube.

[0006] The insulation methods of the three patented technologies mentioned above do not have internal springs. The dynamic insulation only passively expands and contracts with the furnace tube, without elastically expanding and contracting with the thermal expansion and contraction of the furnace tube.

[0007] Reference 1, "Soft Sealing Technology for Converter Tubes" (Zhang Yueping, Liu Haiyang, et al., Refining Technology and Engineering, 2012, 42(12):39-42.), introduces the Flextel converter tube sealing sleeve technology. The Flextel converter tube sealing sleeve uses elastic metal wire, which seems to have the intention of elastic active expansion and contraction. However, according to the introduction in Reference 1, its heat preservation effect is not ideal. There are still exposed parts of the furnace tube. In addition, the shrinkage of the insulation sleeve is irregular. It is just passively squeezed together and cannot automatically expand with the expansion of the furnace tube. Its elastic metal wire has limited effect.

[0008] To achieve elastic expansion and contraction in existing furnace tube insulation sleeves, suitable spring supports need to be found.

[0009] The diaphragm spring is a key component of an automotive diaphragm clutch. The clutch is engaged and disengaged by the release bearing pulling or pushing the diaphragm spring. The diaphragm spring is a tapered spring plate made of thin spring steel, with many evenly distributed radial grooves in its center. It is a type of disc spring, consisting of a disc spring section and a release finger section. The diaphragm spring has a flat shape; although its diameter is relatively large, it does not occupy much radial dimension, and its small height makes the axial dimensions of the clutch compact, facilitating its arrangement within limited installation space.

[0010] Diaphragm springs, with their small height, offer the advantage of a compact axial dimension for clutches, making them ideal for the spring support requirements of dynamic insulation sleeves for furnace tubes. This provides a possibility for dynamic elastic expansion and contraction insulation of reformer tubes in space-constrained environments. However, existing diaphragm spring technology has been limited to the clutch field and has not been seen in the reformer field of hydrocarbon steam reforming units, particularly in the application of reformer tube insulation sleeves.

[0011] In summary, existing furnace tube insulation sleeves differ in several ways. The first type lacks internal springs or elastic supports, resulting in passive expansion and contraction of the furnace tubes with dynamic insulation, without elastic expansion and contraction in response to thermal changes. The second type, while containing elastic metal wires, suffers from poor elasticity, exhibiting limited ability to automatically re-expand after compression. Diaphragm springs, despite their numerous advantages, are currently limited to clutch applications and have not yet been formally applied to the conversion furnace field, particularly in the insulation sleeves of conversion furnace tubes within hydrocarbon steam reforming units. Summary of the Invention

[0012] Based on the above technical background, the purpose of this invention is to provide a furnace tube insulation sleeve that can solve the problems in the prior art where the dynamic insulation of the insulation sleeve only passively expands and contracts with the furnace tube, without elastically expanding and contracting with the thermal expansion and contraction of the furnace tube, thus making the dynamic insulation effect of the furnace tube better.

[0013] To achieve the above objectives, the technical solution of the present invention is as follows:

[0014] A furnace tube insulation sleeve, characterized in that: the furnace tube insulation sleeve comprises two semi-annular insulation sleeves, the cross-section of each semi-annular insulation sleeve being hollow and heart-shaped, including an elastic frame, an insulation layer, an inner protective film, and an outer protective film. The elastic frame is formed by an upper diaphragm spring and a lower diaphragm spring interlocking together. Each upper and lower diaphragm spring includes a semi-circular disc, multiple separating fingers, a self-locking hole, and a self-locking buckle. The semi-circular disc is a planar semi-circular ring, the separating fingers are conical surfaces, and there is a radial groove between adjacent separating fingers. Multiple pinholes are provided along the semi-circular ring on the semi-circular disc, and the bottom ends of the separating fingers are evenly distributed on the inner ring of the semi-circular disc and are integral with the semi-circular disc. The separation fingers are formed with semi-circular tips. The separation fingers of the upper diaphragm spring protrude upwards, while those of the lower diaphragm spring are concave downwards. The semi-circular tips of the upper diaphragm spring bend downwards, and those of the lower diaphragm spring bend upwards. The outer layer of the elastic frame is covered with an inner protective film, an insulation layer, and an outer protective film from the inside out. A self-locking buckle is set at one end of the semi-circular discs of the upper and lower diaphragm springs, and a self-locking hole is set at the other end of the semi-circular discs of the upper and lower diaphragm springs. The two semi-circular insulation sleeves are joined together through the self-locking hole and the self-locking buckle to form a complete furnace tube insulation sleeve.

[0015] The present invention provides a furnace tube insulation sleeve, the further technical feature of which is that: the upper diaphragm spring and the lower diaphragm spring are fastened together by interlocking the semicircular discs and preferably fixed by locking the edges through pinholes, and the locking method preferably uses multiple U-shaped clips for fixing.

[0016] The present invention provides a furnace tube insulation sleeve, the further technical feature of which is that the elastic frame, inner protective film, insulation layer and outer protective film are sewn together as one piece using high temperature resistant stitching.

[0017] The present invention provides a furnace tube insulation sleeve, the further technical feature of which is that the cone angle of the separating finger is 10° to 60°, preferably 30° to 45°.

[0018] This invention is mainly used in the converters of hydrocarbon steam reforming units, such as the first-stage converters of ammonia synthesis units, methanol units, and hydrogen production units. It is an upgraded product of the patented CN201827600U insulation sleeve, which can actively and elastically expand and contract with the thermal expansion and contraction of the converter tubes. Compared with the passive expansion and contraction of the patented CN201827600U insulation sleeve, it has a better insulation effect.

[0019] The advantages of this invention compared to the prior art are as follows:

[0020] 1) The expansion and contraction of the furnace tube insulation sleeve of the present invention are all provided with elastic support by diaphragm springs, and the extension height is basically the same;

[0021] 2) The furnace tube insulation sleeve of the present invention is composed of two semi-circular insulation sleeves, which is more suitable for on-site installation of existing converter furnace tubes;

[0022] 3) The furnace tube insulation sleeve of the present invention can be used independently or multiple insulation sleeves can be combined. The structure is simple and conducive to mass production.

[0023] 4) The furnace tube insulation sleeve of the present invention can actively and elastically expand and contract with the thermal expansion and contraction of the furnace tube, which has a better insulation effect than the passive expansion and contraction furnace tube insulation sleeve of the prior art.

[0024] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments, but the accompanying drawings and specific embodiments do not limit the scope of the present invention. Attached Figure Description

[0025] Figure 1 This is a 3D view of the semi-circular heat insulation sleeve of the present invention;

[0026] Figure 2 This is a 3D view of the two semi-annular insulation sleeves before they are joined together in this invention;

[0027] Figure 3 This is a 3D view of the two semi-circular insulation sleeves after they are joined together according to the present invention;

[0028] Figure 4 This is a 3D view of the upper diaphragm spring of the present invention;

[0029] Figure 5 This is a 3D view of the lower diaphragm spring of the present invention.

[0030] Figure 6 This is a 3D view of the elastic frame of the present invention;

[0031] Figure 7 This is a 3D view of the two sets of elastic frames after docking according to the present invention;

[0032] Figure 8 This is a diagram showing the effect of installing the insulation sleeve of the present invention on the furnace tube of the converter.

[0033] The attached figures are labeled as follows:

[0034] 100. Semi-circular insulation sleeve;

[0035] 1. Flexible frame; 2. Insulation layer; 3. Inner protective film; 4. Outer protective film;

[0036] 5. Overlock stitching; 6. Seam thread; 7. Central through-hole;

[0037] 10. Upper diaphragm spring;

[0038] 11. Semicircular disc; 12. Separating finger; 13. Semi-circular fingertip; 14. Radial slot;

[0039] 15. Pinhole; 16. Self-locking hole; 17. Self-locking buckle; 18. Center window;

[0040] 20. Lower diaphragm spring;

[0041] 21. Semicircular disk; 22. Separating finger; 23. Semi-circular fingertip; 24. Radial slot;

[0042] 25. Pinhole; 26. Self-locking hole; 27. Self-locking buckle; 28. Center window;

[0043] 30. U-shaped clip; 35. Center window;

[0044] 50. Furnace tube; 60. Furnace refractory material; 70. Furnace top plate; 80. Furnace tube flange. Detailed Implementation

[0045] The invention will now be described in more detail with reference to the accompanying drawings. While preferred embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0046] Example

[0047] Figures 1 to 8 All dimensions listed are assumed for ease of representation and are not limited by these values ​​in actual design. They should be determined based on the actual diameter of the furnace tube.

[0048] Figure 1 The image shown is a 3D view of the semi-annular insulation sleeve 100 of the present invention. The semi-annular insulation sleeve 100 of the present invention is semi-annular, comprising an elastic frame 1, an insulation layer 2, an inner protective film 3, and an outer protective film 4. The vertical hollow portion of the semi-annular insulation sleeve 100 forms a semi-central through hole 7. The cross-section of the semi-annular insulation sleeve 100 is hollow and heart-shaped. The components in the cross-section, from the inside out, are: elastic frame 1, inner protective film 3, insulation layer 2, and outer protective film 4. The elastic frame 1, inner protective film 3, insulation layer 2, and outer protective film 4 are assembled into one unit by sutures 6, preferably using high-temperature resistant sutures.

[0049] The elastic frame 1 is preferably made of stainless steel that can withstand temperatures above 600°C;

[0050] The insulation layer 2 is preferably a ceramic fiber blanket that can withstand temperatures above 700℃;

[0051] The inner protective film 3 and the outer protective film 4 are preferably ceramic fiber cloths that can withstand temperatures above 700℃;

[0052] The locking edge 5 is preferably made of steel wire or refractory fiber thread containing steel wire that can withstand temperatures above 700°C;

[0053] The suture 6 is preferably a fire-resistant fiber thread containing steel wire that can withstand temperatures above 700℃.

[0054] The elastic frame 1 consists of an upper diaphragm spring 10 (see...) Figure 4 ) and lower diaphragm spring 20 (see Figure 5 The upper diaphragm spring 10 and the lower diaphragm spring 20 are formed by interlocking. Each includes a semi-circular disc, multiple separating fingers, a self-locking hole, and a self-locking buckle. The semi-circular disc is a flat semi-circular ring, and the separating fingers are conical. A radial groove is formed between adjacent separating fingers. Multiple pinholes are provided along the semi-circular ring on the semi-circular disc. The bottom ends of the separating fingers are evenly distributed on the inner ring of the semi-circular disc and integrally formed with it. The tops of the separating fingers are semi-arc tips. The separating fingers of the upper diaphragm spring 10 protrude upwards, while the separating fingers of the lower diaphragm spring 20 are concave downwards. The semi-circular fingertips of spring 10 bend downwards, while the semi-circular fingertips of the lower diaphragm spring 20 bend upwards. The outer layer of the elastic frame 1 is sequentially covered from the inside out with an inner protective film 3, an insulation layer 2, and an outer protective film 4. A self-locking buckle is located at one end of the semi-circular discs of the upper diaphragm spring 10 and the lower diaphragm spring 20. A self-locking hole is located at the other end of the semi-circular discs of the upper diaphragm spring 10 and the lower diaphragm spring 20. The two semi-annular insulation sleeves 100 are joined together through the self-locking hole and the self-locking buckle to form a complete furnace tube insulation sleeve (see...). Figure 3 ).

[0055] Figure 2 The image shows a 3D view of the two semi-circular insulation sleeves 100 before they are joined together. The two semi-circular insulation sleeves 100 are connected by self-locking buckles 27 and self-locking holes 26 on the elastic frame 1 to form a complete insulation sleeve.

[0056] Figure 3 The image shows a 3D view of two interlocking insulation sleeves 100. The two semi-annular insulation sleeves 100 interlock to form a complete insulation sleeve unit. The vertical hollow portion of this complete insulation sleeve unit forms a complete central through-hole 7, which contains a V-shaped wave. In application, the furnace tube passes through the central through-hole 7. The interlocking connection of the two semi-annular insulation sleeves 100 is ideal for on-site insulation of existing furnace tubes.

[0057] Figure 4 The image shown is a 3D view of the upper diaphragm spring 10 of the present invention. (See image for details.) Figure 4As shown, the upper diaphragm spring 10 consists of a semicircular disc 11, separating fingers 12, and a self-locking buckle 17. There are multiple separating fingers 12, with a semi-circular fingertip 13 being a part of each separating finger 12, located at its tip and bent downwards. The semicircular disc 11 is a planar semicircular ring, and the separating fingers 12 are conical springs with a 30° cone angle (except for the semi-circular fingertip 13), protruding upwards. A radial slot 14 exists between adjacent separating fingers 12. Multiple pinholes 15 are provided along the semicircular ring on the semicircular disc 11. A self-locking hole 16 is located at one end of the semicircular disc 11, and the self-locking buckle 17 is located at the other end of the semicircular disc 11. The vertical hollow portion of the upper diaphragm spring 10 forms a central window 18.

[0058] Except for the self-locking buckle 17, the upper diaphragm spring 10 is stamped from a stainless steel sheet that can withstand temperatures above 600℃. The self-locking buckle 17 is welded to... Figure 4 The end of the semi-disc 11 shown is separated from the protruding side of the finger 12, that is, one end of the semi-disc 11.

[0059] like Figure 4 As shown, the outer diameter of the semicircular disk 11 of the upper diaphragm spring 10 is Φ290mm, the radius of the central window 18 is R76mm, the distance between the top of the separating finger 12 and the bottom surface of the semicircular disk 11 is 30mm, and the bending radius of the semi-arc fingertip 13 is R6mm.

[0060] Figure 5 The image shown is a 3D view of the lower diaphragm spring 20 of the present invention. (As shown...) Figure 5 As shown, the lower diaphragm spring 20 consists of a semicircular disc 21, a separating finger 22, and a self-locking latch 27. The semi-circular fingertip 23 is part of the separating finger 22, located at the top of the separating finger 12 and curved upwards. The semicircular disc 21 is a planar semicircular ring, and the separating finger 22 is a conical spring with a cone angle of -30° (except for the semi-circular fingertip 13), with the separating finger 22 recessed downwards. Radial slots 24 are located between the multiple separating fingers 22, and pinholes 25 and self-locking holes 26 are located on the semicircular disc 21. The vertical hollow portion of the lower diaphragm spring 20 forms a central window 28.

[0061] Except for the self-locking buckle 27, the lower diaphragm spring 20 is stamped from a stainless steel sheet that can withstand temperatures above 600℃. The self-locking buckle 27 is welded to... Figure 5 The end of the semi-disc 21 shown is separated from the concave side of the finger 12, that is, one end of the semi-disc 21.

[0062] like Figure 5 As shown, the outer diameter of the semicircular disk 21 of the lower diaphragm spring 20 is Φ290mm, the radius of the central window 28 is R76mm, the distance between the lowest end of the separating finger 22 and the top surface of the semicircular disk 21 is 30mm, and the bending radius of the semi-arc fingertip 23 is R6mm.

[0063] Figure 6This is a 3D view of the elastic frame 1 of the present invention. (See attached image.) Figure 6 As shown, the elastic frame 1 is formed by interlocking an upper diaphragm spring 10 and a lower diaphragm spring 20, and is fixed by clamping the semicircular disc 11 and semicircular disc 21 with multiple U-shaped clips 30. After the upper diaphragm spring 10 and the lower diaphragm spring 20 are interlocked, the central window 18 of the upper diaphragm spring 10 and the central window 28 of the lower diaphragm spring 20 overlap to form a central window 35. After the elastic frame 1 is covered with an inner protective film 3, a heat insulation layer 2, and an outer protective film 4, it is sewn together with a locking edge 5 and a sewing thread 6 to form the desired shape. Figure 1 The semi-annular heat-insulating sleeve 100 of the present invention is shown. After the elastic frame 1 is covered, Figure 6 The center window 35 in the middle becomes Figure 1 The center through hole 7.

[0064] Figure 7 This is a 3D view of the two sets of numbered 1 after docking according to the present invention. For example... Figure 7 As shown, the two sets of elastic frames 1 are connected, and the self-locking buckles 17 and 27, along with the self-locking holes 16 and 26, lock together to form a complete ring. The central windows 35 of the two sets of elastic frames 1 are connected to form a closed central window 35.

[0065] Figure 8 This is a diagram showing the effect of installing the furnace tube insulation sleeve of the present invention on the furnace tube of the converter. Figure 8 As shown, five furnace tube insulation sleeves of the present invention are used. The furnace tube 50 passes through the refractory material 60 inside the furnace and the furnace top plate 70, extends out of the furnace top, and connects to the furnace tube flange 80. In this embodiment, the outer diameter of the furnace tube 50 is 125mm. The furnace tube 50 located between the furnace top plate 70 and the furnace top flange 80 needs to be insulated. In this embodiment, the length of the furnace tube 50 between the furnace top plate 70 and the furnace top flange 80 is 250mm in the cold state, and the length in the hot state is approximately 230mm longer than that in the cold state. In this embodiment, the insulation sleeve of the present invention has a single axial height of 50mm when compressed and 100mm when fully expanded. Figure 8 As shown, in the cold state, five insulating sleeves are compressed and installed on the outside of the furnace tube 50, forming five elastic insulating sleeves. During operation, the furnace tube gradually expands after being heated, and the insulating sleeves gradually spring open accordingly. Finally, the furnace tube extends to approximately 230mm and stabilizes, and the five elastic insulating sleeves also spring open 230mm to provide insulation. When the converter stops operating, the furnace tube 50 gradually cools down and contracts, and the insulating sleeves are compressed accordingly, returning to its cold state.

Claims

1. A furnace tube insulation sleeve, characterized in that: The furnace tube insulation sleeve includes two semi-annular insulation sleeves. The cross-section of each semi-annular insulation sleeve is hollow and includes an elastic frame, an insulation layer, an inner protective film, and an outer protective film. The elastic frame is formed by interlocking upper and lower diaphragm springs. Each upper and lower diaphragm spring includes a semi-circular disc, multiple separating fingers, a self-locking hole, and a self-locking buckle. The semi-circular disc is a planar semi-circular ring, and the separating fingers are conical. There is a radial slot between two adjacent separating fingers. Multiple pinholes are provided along the semi-circular ring on the semi-circular disc. The bottom of the separating fingers is evenly distributed on the inner ring of the semi-circular disc and is integrally formed with the semi-circular disc. The top of the separating fingers... The ends are semi-circular fingertips. The separation direction of the upper diaphragm spring protrudes upward, while the separation direction of the lower diaphragm spring is concave downward. The semi-circular fingertips of the upper diaphragm spring bend downward, and the semi-circular fingertips of the lower diaphragm spring bend upward. The outer layer of the elastic frame is covered with an inner protective film, an insulation layer, and an outer protective film from the inside out. A self-locking buckle is set at one end of the semi-circular discs of the upper and lower diaphragm springs. A self-locking hole is set at the other end of the semi-circular discs of the upper and lower diaphragm springs. The two semi-circular insulation sleeves are connected through the self-locking hole and the self-locking buckle to form a complete furnace tube insulation sleeve.

2. The furnace tube insulation sleeve according to claim 1, characterized in that: The upper and lower diaphragm springs are interlocked by their semicircular discs and then secured with a locking edge through a pinhole.

3. The furnace tube insulation sleeve according to claim 2, characterized in that: The edge-locking method is to use U-shaped clips.

4. The furnace tube insulation sleeve according to claim 1, characterized in that: The elastic frame, inner protective film, insulation layer and outer protective film are sewn together with high-temperature resistant sutures.

5. A furnace tube insulation sleeve according to claim 1, characterized in that: The cone angle of the separating finger's cone surface is 10°~60°.

6. A furnace tube insulation sleeve according to claim 1 or 5, characterized in that: The cone angle of the separating finger is 30°~45°.

Images