A furnace tube limiting device of an industrial furnace and an industrial furnace

Abstract

The application discloses a furnace tube limiting device of an industrial furnace and the industrial furnace, and relates to the technical field of industrial furnaces, which comprises a limiting sleeve pipe, a furnace wall plate of the industrial furnace; a furnace tube extension pipe, one end of the furnace tube extension pipe movably penetrating into one end of the limiting sleeve pipe, the other end of the furnace tube extension pipe being used for being connected with a free end of a furnace tube; a fixed core rod, one end of the fixed core rod penetrating into the limiting sleeve pipe and being detachably connected with one end of the furnace tube extension pipe, the other end of the fixed core rod being connected with the other end of the limiting sleeve pipe and / or the other end of the fixed core rod being connected with the outside of the furnace wall plate; the limiting device is characterized in that the furnace tube extension pipe is arranged at the free end of the furnace tube, the furnace tube extension pipe movably penetrating into the limiting sleeve pipe, so that the space requirement of the free end of the furnace tube is met, and the free end of the furnace tube is fixed through the connection between the fixed core rod and the furnace tube extension pipe during transportation, thereby protecting the furnace tube.

Description

Technical Field

[0001] This invention belongs to the field of industrial furnace technology, and more specifically, relates to a furnace tube limiting device and an industrial furnace. Background Technology

[0002] In both domestic and international petrochemical projects, the construction method of transporting industrial furnaces as modular units or complete furnace modules, assembled at the manufacturing plant and then installed on-site, is becoming increasingly popular and is gaining recognition and favor from owners and project contractors. Transporting modular units or complete furnace modules means assembling the steel structure, lining, piping, and even ladder platforms of the industrial furnace into a single unit, subjecting them to complex moving and installation processes including lifting / hoisting, land transport, and ocean transport.

[0003] Riser systems are one of the most common furnace tube arrangements in industrial furnaces of petrochemical plants. Vertical risers typically employ an upper suspended support structure, with the lower end serving as a free expansion point. As a core component of the industrial furnace, the piping system bears the core function of heat transfer and is one of the key protected objects during construction and transportation. Considering thermal expansion, the support method for the piping system within the furnace often requires a combination of fixed supports and free-end limiting and guiding structures. However, the free-end limiting and restraints used in on-site construction cannot meet the stability and strength requirements of the overall movement and installation of the industrial furnace in terms of strength, structure, and restraint direction. Furthermore, simple piping reinforcement measures cannot meet the expansion requirements of the free ends of the piping, and because it needs to be connected to the furnace steel structure, its installation and removal will require the on-site installation of local lining structures, increasing the on-site installation workload. At the same time, the removal of reinforcement measures and restoration of the lining can easily damage the piping system itself, local linings, burners, and other installed vulnerable components. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a furnace tube limiting device and an industrial furnace. By setting a furnace tube extension tube at the free end of the furnace tube, the furnace tube extension tube can be movably inserted into the limiting sleeve. This satisfies the space requirements of the free end of the furnace tube and also allows the free end of the furnace tube to be fixed during transportation by connecting the fixing mandrel to the furnace tube extension tube, thus protecting the furnace tube.

[0005] To achieve the above objectives, the present invention provides a furnace tube limiting device for an industrial furnace. The furnace tube comprises multiple straight tubes arranged parallel to each other in a vertical direction. The upper and lower ends of the straight tubes are connected to adjacent straight tubes through upper and lower bends, respectively, forming a serpentine shape. The bottom of the industrial furnace is provided with a furnace wall plate. The limiting device includes:

[0006] A limiting sleeve penetrates the furnace wall panel;

[0007] A furnace tube extension tube, one end of which passes through the top end of the limiting sleeve, and the other end of which is used to connect to a lower bend of the furnace tube.

[0008] A fixing mandrel is detachably inserted into the furnace tube extension tube through the bottom end of the limiting sleeve. One end of the fixing mandrel is connected to one end of the furnace tube extension tube, and the other end of the fixing mandrel is connected to the bottom end of the limiting sleeve and / or the other end of the fixing mandrel is connected to the outer side of the furnace wall plate.

[0009] Optionally, the limiting sleeve includes:

[0010] The casing body is cylindrical;

[0011] The connecting plate is ring-shaped and is sleeved on the outer periphery of the sleeve body.

[0012] Optionally, the furnace wall panel is provided with a sleeve connection hole, the sleeve body is inserted into the sleeve connection hole, the connecting plate is welded to the lower surface of the furnace wall panel, and the outer diameter of the connecting plate is 40-100mm larger than the diameter of the sleeve connection hole.

[0013] Optionally, it also includes a cap, which is detachably connected to the bottom end of the limiting sleeve when the fixing mandrel is removed from the limiting sleeve, and the cap can block the bottom end of the limiting sleeve.

[0014] Optionally, the cap includes a disc portion, a first nut is provided at the center of one side of the disc portion, and a cylindrical portion is provided on the other side of the disc portion. One end of the cylindrical portion is connected to the outer periphery of the disc portion, and the other end of the cylindrical portion is provided with a plurality of plate-shaped teeth, which are formed by bending from the outer wall of the cylindrical portion toward the interior of the cylindrical portion.

[0015] Optionally, an annular groove is provided on the outer periphery of the bottom end of the limiting sleeve, and multiple notches that cooperate with the plate-shaped teeth are provided on the groove wall on the side of the annular groove away from the furnace wall plate.

[0016] Optionally, the furnace tube extension includes:

[0017] The extension tube body is cylindrical, and the inner wall of the extension tube body is provided with internal threads;

[0018] The reinforcing joint is a variable cross-section structure with a large cross-section at one end and a small cross-section at the other end. The large cross-section end of the reinforcing joint is used to connect with the lower elbow, and the small cross-section end of the reinforcing joint is connected with the extension pipe body.

[0019] Optionally, the fixing mandrel includes:

[0020] The mandrel body is cylindrical, and an external thread is provided on the outer surface of one end of the mandrel body, which mates with the internal thread;

[0021] A stop plate is sleeved on the other end of the mandrel body and located below the furnace wall plate. It is used to limit the depth of the mandrel body entering the limiting sleeve. The outer circumferential dimension of the stop plate is larger than the inner circumferential dimension of the limiting sleeve.

[0022] The second nut is threaded to the other end of the mandrel body and is located below the stop end plate.

[0023] The present invention also provides an industrial furnace, comprising:

[0024] The furnace tubes are arranged in a serpentine pattern inside the industrial furnace;

[0025] Furnace tube limiting devices for multiple of the aforementioned industrial furnaces.

[0026] Optionally, the furnace tube includes multiple straight tubes arranged parallel to each other in a vertical direction. The upper and lower ends of the straight tubes are connected to adjacent straight tubes through upper and lower elbows to form a serpentine shape. The upper end of the furnace tube is fixed inside the industrial furnace by a hanging device. The bottom of the industrial furnace is provided with a furnace wall plate. Multiple limiting sleeves are inserted into the furnace wall plate. The other end of the furnace tube extension tube of each furnace tube limiting device is connected to a lower elbow.

[0027] This invention provides a furnace tube limiting device and an industrial furnace, the advantages of which are:

[0028] 1. This limiting device sets a furnace tube extension tube at the free end of the furnace tube, allowing the furnace tube extension tube to move through the limiting sleeve. This satisfies the space requirements of the free end of the furnace tube and also fixes the free end of the furnace tube during transportation by connecting the fixing mandrel to the furnace tube extension tube, thus protecting the furnace tube.

[0029] 2. The limiting device has a cap, which can be used to seal the limiting sleeve after the fixing mandrel is removed upon arrival at the designated location.

[0030] Other features and advantages of the present invention will be described in detail in the following detailed description section. Attached Figure Description

[0031] The above and other objects, features and advantages of the present invention will become more apparent from the more detailed description of exemplary embodiments of the invention in conjunction with the accompanying drawings, wherein the same reference numerals generally represent the same components in the exemplary embodiments of the invention.

[0032] Figure 1A front view schematic diagram of a furnace tube limiting device for an industrial furnace according to an embodiment of the present invention is shown.

[0033] Figure 2 It shows Figure 1 A schematic diagram of the cross-sectional structure along direction A.

[0034] Figure 3 It shows Figure 1 A schematic diagram of the cross-sectional structure along direction B.

[0035] Figure 4 A schematic diagram of the structure of a limiting sleeve for a furnace tube limiting device of an industrial furnace according to an embodiment of the present invention is shown.

[0036] Figure 5 A schematic diagram of the structure of a furnace tube extension tube of a furnace tube limiting device for an industrial furnace according to an embodiment of the present invention is shown.

[0037] Figure 6 A schematic diagram of the structure of the fixing mandrel of a furnace tube limiting device for an industrial furnace according to an embodiment of the present invention is shown.

[0038] Figure 7 A front view structural schematic diagram of the tube cap of a furnace tube limiting device for an industrial furnace according to an embodiment of the present invention is shown.

[0039] Figure 8 A cross-sectional view of the cap of a furnace tube limiting device for an industrial furnace according to an embodiment of the present invention is shown.

[0040] Figure 9 A schematic diagram of the internal structure of an industrial furnace according to an embodiment of the present invention is shown.

[0041] Explanation of reference numerals in the attached figures:

[0042] 1. Limiting sleeve; 2. Furnace wall panel; 3. Furnace tube extension tube; 4. Furnace tube; 5. Fixing mandrel; 6. Sleeve body; 7. Connecting plate; 8. Tube cap; 9. Disc part; 10. First nut; 11. Cylindrical part; 12. Plate tooth; 13. Annular groove; 14. Notch; 15. Extension tube body; 16. Reinforcing joint; 17. Mandrel body; 18. Stop end plate; 19. Second nut; 20. Straight tube; 21. Upper elbow; 22. Lower elbow; 23. Hanging component. Detailed Implementation

[0043] Preferred embodiments of the invention will now be described in more detail. While preferred embodiments of the invention are described below, 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.

[0044] This invention provides a limiting device for furnace tubes of an industrial furnace. The furnace tubes include multiple straight tubes arranged parallel to each other in a vertical direction. The upper and lower ends of the straight tubes are connected to adjacent straight tubes through upper and lower elbows, respectively, forming a serpentine shape. The bottom of the industrial furnace is provided with a furnace wall plate. The limiting device includes:

[0045] Limiting sleeve, penetrating the furnace wall panel;

[0046] Furnace tube extension tube: one end of the furnace tube extension tube is inserted inside the top of the limiting sleeve, and the other end of the furnace tube extension tube is used to connect to a lower bend of the furnace tube.

[0047] A fixed mandrel is detachably inserted into the furnace tube extension tube through the bottom end of a limiting sleeve. One end of the fixed mandrel is connected to one end of the furnace tube extension tube, and the other end of the fixed mandrel is connected to the bottom end of the limiting sleeve and / or the other end of the fixed mandrel is connected to the outer side of the furnace wall panel.

[0048] Specifically, the limiting sleeve can provide limiting and guiding functions for the furnace tube extension tube, and can adapt to the displacement and limiting requirements of the free end of the furnace tube due to the influence of thermal expansion. When the industrial furnace module or whole furnace module is transported, one end of the fixing mandrel is inserted into the limiting sleeve and connected to the furnace tube extension tube, and the furnace tube extension tube is tightened to fix the free end of the furnace tube. This can prevent the furnace tube from displacement and collision caused by bumps and shaking during transportation, and play a role in protecting the furnace tube.

[0049] The other end of the fixing mandrel can be connected to the bottom end of the limiting sleeve to fix the fixing mandrel and tighten the furnace tube extension tube. The other end of the fixing mandrel can also be provided with a vertical part, which is connected to the outside of the furnace wall panel to achieve the effect of fixing the fixing mandrel and tightening the furnace tube extension tube.

[0050] In one example, the furnace tube extension is welded to the outside of the elbow at the free end of the furnace tube, and the limiting sleeve is welded to the furnace wall plate at the corresponding position of the furnace tube extension. Before the industrial furnace module or the entire furnace module is started, the fixing mandrel is screwed into the furnace tube extension, so that the furnace tube is fixed in tension between the tube support and the furnace bottom plate, and the tension is transmitted along the connecting plate of the fixing mandrel to the limiting sleeve, and then to the outer wall of the furnace. This prevents the furnace tube from being moved by external forces (such as road bumps, tire blowouts of transport vehicles, waves, etc.) or inertial forces (such as when braking) during transportation, and prevents the furnace tube from hitting or falling out of the furnace tube support. This realizes the limiting protection function of the furnace tube during the transportation of the industrial furnace body.

[0051] Optionally, the limiting sleeve includes:

[0052] The casing body is cylindrical;

[0053] The connecting plate is ring-shaped and is fitted around the outer circumference of the sleeve body.

[0054] Specifically, the connecting plate serves to position the sleeve body, and the limiting sleeve can be welded to the furnace body through the connecting plate.

[0055] Optionally, a sleeve connection hole is provided on the furnace wall panel, the sleeve body is inserted into the sleeve connection hole, and the connecting plate is welded to the lower surface of the furnace wall panel. The outer diameter of the connecting plate is 40-100mm larger than the diameter of the sleeve connection hole.

[0056] Specifically, the connecting plate can cover the sleeve connection hole on the furnace wall plate, and has a spare width of 20-50mm on one side. The inner diameter of the limiting sleeve should be 20-80mm larger than the outer diameter of the furnace tube extension pipe. The limiting sleeve is installed after the furnace tube is installed and adjusted. The position of the limiting sleeve can be locally adjusted according to the installation position of the furnace tube.

[0057] Optionally, it also includes a cap, which is detachably connected to the bottom end of the limiting sleeve when the fixing mandrel is removed from the limiting sleeve, and the cap can seal the bottom end of the limiting sleeve.

[0058] Specifically, after the fixed mandrel is removed upon arrival at the designated location, the limiting sleeve is sealed with a cap to prevent outside air from entering the industrial furnace.

[0059] Optionally, the cap includes a disc portion, a first nut is provided at the center of one side of the disc portion, and a cylindrical portion is provided on the other side of the disc portion. One end of the cylindrical portion is connected to the outer periphery of the disc portion, and the other end of the cylindrical portion is provided with a plurality of plate-shaped teeth, which are formed by bending from the outer wall of the cylindrical portion toward the interior of the cylindrical portion.

[0060] Specifically, the side of the plate-shaped teeth facing the disc is set as the first inclined surface; an annular groove is provided on the outer side of the other end of the sleeve body, and a notch that cooperates with the plate-shaped teeth is opened on the groove wall on the side of the annular groove away from the connecting plate. The notch can accommodate the plate-shaped teeth to pass through, and the notch divides the groove wall into multiple locking blocks. The side of the locking block near the connecting plate is set as the second inclined surface, and the second inclined surface cooperates with the first inclined surface.

[0061] Optionally, an annular groove is provided on the outer periphery of the bottom end of the limiting sleeve, and multiple notches that cooperate with the plate-shaped teeth are opened on the groove wall on the side away from the furnace wall plate.

[0062] Specifically, the limiting sleeve is installed on the outer surface of the end of the furnace wall, which is partially necked to form an annular groove. The inner side of the annular groove is made of intermittent beveled teeth, and the open part of the intermittent beveled teeth is notched, which allows the plate-shaped teeth to pass through and enter the annular groove. The tube cap is made of 3 to 5 protruding plate-shaped teeth, the size of which matches the size of the notch. After the industrial furnace is installed, the plate-shaped teeth can be opened into the annular groove through the notch and screwed on during actual production. The first bevel and the second bevel are used to achieve fastening and seal the end face of the limiting sleeve that penetrates the furnace wall. The first nut is convenient for installing or removing the tube cap with conventional tools.

[0063] Optionally, the furnace tube extension includes:

[0064] The extension tube body is cylindrical, and the inner wall of the extension tube body is provided with internal threads;

[0065] The reinforcing joint is a variable cross-section structure with a large cross-section at one end and a small cross-section at the other. The large cross-section end of the reinforcing joint is used to connect with the lower elbow, and the small cross-section end of the reinforcing joint is connected with the extension pipe body.

[0066] Specifically, the furnace tube extension tube is made by welding a reinforced joint to the extension tube body made of internally threaded thick-walled steel pipe. The large-section end of the reinforced joint is welded to the free end of the furnace tube, which increases the welding area, reduces local stress concentration, and increases the connection strength compared to conventional furnace tube end extension tubes. The internal thread of the internally threaded thick-walled steel pipe is a coarse-tooth internal thread that can withstand heavy loads and matches the coarse-tooth external thread on the transport and fixing mandrel.

[0067] Optionally, the mandrel includes:

[0068] The mandrel body is cylindrical, and the outer surface of one end of the mandrel body is provided with external threads, which are matched with internal threads;

[0069] The stop end plate is sleeved on the other end of the mandrel body and located below the furnace wall plate. It is used to limit the depth of the mandrel body entering the limiting sleeve. The outer circumferential dimension of the stop end plate is larger than the inner circumferential dimension of the limiting sleeve.

[0070] The second nut is threaded to the other end of the mandrel body and is located below the stop end plate.

[0071] Specifically, the mandrel body is made of solid steel bar or thick-walled steel pipe. The outer wall of the steel bar or thick-walled steel pipe is machined with coarse thread, which has good stress and fatigue resistance and is easy to disassemble and assemble. The end of the mandrel body is welded with a stop plate, and a second nut is welded to the stop plate. The stop plate plays the role of force transmission and preventing the mandrel from being over-tightened. The second nut makes it easy to screw the mandrel in or out with conventional tools.

[0072] In one example, the outer side of the cap features an embossed structure with a depth of 0.5-1mm in the circumferential direction, which facilitates manual rotation and disassembly.

[0073] The present invention also provides an industrial furnace, comprising:

[0074] The furnace tubes are arranged in a serpentine pattern inside the industrial furnace;

[0075] Furnace tube limiting devices for multiple of the aforementioned industrial furnaces.

[0076] Optionally, the furnace tube includes multiple straight tubes arranged in parallel along the vertical direction. The upper and lower ends of the straight tubes are connected to adjacent straight tubes through upper and lower elbows to form a serpentine shape. The upper end of the furnace tube is fixed inside the industrial furnace by a hanging device. The bottom of the industrial furnace is provided with a furnace wall plate. Multiple limiting sleeves are inserted inside the furnace wall plate. The other end of the furnace tube extension of each furnace tube limiting device is connected to a lower elbow.

[0077] Specifically, the upper elbow and the lower elbow are semi-circular or U-shaped structures. The other end of the furnace tube extension pipe is welded to the symmetrical axis of the lower elbow. The limiting sleeve is welded inside the furnace wall plate according to the actual installation and adjustment position of the furnace tube, which plays a role in limiting and guiding the furnace tube extension pipe.

[0078] Example

[0079] like Figures 1 to 9 As shown, this invention provides a furnace tube limiting device for an industrial furnace. The furnace tube includes multiple straight tubes arranged parallel to each other in a vertical direction. The upper and lower ends of the straight tubes are connected to adjacent straight tubes through upper and lower elbows, respectively, forming a serpentine shape. The bottom of the industrial furnace is provided with a furnace wall plate. The limiting device includes:

[0080] Limiting sleeve 1, penetrating furnace wall plate 2;

[0081] Furnace tube extension pipe 3, one end of which is inserted inside the top end of the limiting sleeve 1, and the other end of which is used to connect to a lower bend 22 of the furnace tube 4.

[0082] The fixing mandrel 5 is detachably inserted into the furnace tube extension tube 3 through the bottom end of the limiting sleeve 1. One end of the fixing mandrel 5 is connected to one end of the furnace tube extension tube 3, and the other end of the fixing mandrel 5 is connected to the bottom end of the limiting sleeve 1.

[0083] Optionally, the limiting sleeve 1 includes:

[0084] The sleeve body 6 is cylindrical;

[0085] The connecting plate 7 is ring-shaped and is sleeved on the outer periphery of the sleeve body 6.

[0086] Optionally, the furnace wall panel 2 is provided with a sleeve connection hole, the sleeve body 6 is inserted into the sleeve connection hole, and the connecting plate 7 is welded to the lower surface of the furnace wall panel 2. The outer diameter of the connecting plate 7 is 40-100mm larger than the diameter of the sleeve connection hole.

[0087] Optionally, it also includes a cap 8, which is detachably connected to the bottom end of the sleeve body 6 when the fixing mandrel 5 is removed from the limiting sleeve 1, and the cap 8 can seal the bottom end of the sleeve body 6.

[0088] Optionally, the cap 8 includes a disc portion 9, a first nut 10 is provided at the center of one side of the disc portion 9, and a cylindrical portion 11 is provided on the other side of the disc portion 9. One end of the cylindrical portion 11 is connected to the outer periphery of the disc portion 9, and the other end of the cylindrical portion 11 is provided with a plurality of plate-shaped teeth 12, which are formed by bending from the outer wall of the cylindrical portion 11 toward the interior of the cylindrical portion 11.

[0089] Optionally, an annular groove 13 is provided on the outer periphery of the bottom end of the sleeve body 6, and multiple notches 14 that cooperate with the plate teeth 12 are provided on the groove wall of the annular groove 13 on the side away from the connecting plate 7.

[0090] Optionally, the furnace tube extension tube 3 includes:

[0091] The extension tube body 15 is cylindrical, and the inner wall of the extension tube body 15 is provided with internal threads.

[0092] The reinforcing joint 16 has a tapered structure. The large cross-section end of the reinforcing joint 16 is used to connect with the lower elbow 22, and the small cross-section end of the reinforcing joint 16 is connected with the extension pipe body 15.

[0093] Optionally, the fixing mandrel 5 includes:

[0094] The core rod body 17 is cylindrical, and the outer surface of one end of the core rod body 17 is provided with an external thread, which is matched with the internal thread.

[0095] The stop end plate 18 is sleeved on the other end of the mandrel body 17 and located below the furnace wall plate 2. It is used to limit the depth of the mandrel body 17 entering the limiting sleeve 1. The outer diameter of the stop end plate 18 is larger than the inner diameter of the limiting sleeve 1.

[0096] The second nut 19 is threaded to the other end of the mandrel body 17 and is located below the stop end plate 18.

[0097] The present invention also provides an industrial furnace, comprising:

[0098] Furnace tubes 4 are arranged in a serpentine pattern inside the industrial furnace;

[0099] Furnace tube limiting devices for multiple of the aforementioned industrial furnaces.

[0100] Optionally, the furnace tube 4 includes multiple straight tubes 20 arranged in parallel along the vertical direction. The upper and lower ends of the straight tubes 20 are connected to adjacent straight tubes 20 through upper bends 21 and lower bends 22 to form a serpentine shape. The upper end of the furnace tube 4 is fixed inside the industrial furnace by a hanging member 23. The bottom of the industrial furnace is provided with a furnace wall plate 2. Multiple limiting sleeves 1 are inserted into the furnace wall plate 2. The other end of the furnace tube extension tube 3 of each furnace tube limiting device is connected to a lower bend 22.

[0101] In summary, when using the furnace tube limiting device for the industrial furnace provided by this invention, a sleeve connection hole is opened on the furnace wall plate 2 at the bottom of the industrial furnace, and the limiting sleeve 1 is welded into the sleeve connection hole. A furnace tube extension pipe 3 is welded onto the lower bend 22 of the furnace tube 4, and one end of the furnace tube extension pipe 3 is movably inserted into the limiting sleeve 1. When the entire industrial furnace module is transported, a fixing mandrel 5 is inserted into the limiting sleeve 1 from the bottom of the industrial furnace and tightened with the furnace tube extension pipe 3 through a coarse thread, thus controlling the movement of the furnace tube 4. A tension force is applied from one end to fix the free end of the furnace tube 4, thus protecting the furnace tube 4 during transportation. After the industrial furnace is transported to its destination, the fixing mandrel 5 is removed, and the cap 8 is screwed onto the end of the limiting sleeve 1 to seal the limiting sleeve 1. At this time, the furnace tube extension tube 3 can move within the limiting sleeve 1 to form a free end, which can meet the requirements of limiting the free end of the furnace tube 4 and guiding thermal expansion displacement. This limiting device has a simple structure, low cost, convenient operation, and good performance.

[0102] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A furnace tube limiting device for an industrial furnace, wherein the furnace tube comprises multiple straight tubes arranged parallel to each other in a vertical direction, the upper and lower ends of the straight tubes being connected to adjacent straight tubes in a serpentine shape via upper and lower elbows respectively, and the bottom of the industrial furnace is provided with a furnace wall plate, characterized in that, The limiting device includes: A limiting sleeve penetrates the furnace wall panel; A furnace tube extension tube, one end of which passes through the top end of the limiting sleeve, and the other end of which is used to connect to a lower bend of the furnace tube. A fixing mandrel is detachably inserted into the furnace tube extension tube through the bottom end of the limiting sleeve. One end of the fixing mandrel is connected to the bottom end of the furnace tube extension tube, and the other end of the fixing mandrel is connected to the bottom end of the limiting sleeve and / or the other end of the fixing mandrel is connected to the outer side of the furnace wall plate. The furnace tube extension tube includes: The extension tube body is cylindrical, and the inner wall of the extension tube body is provided with internal threads; The fixing core rod includes: The mandrel body is cylindrical, and an external thread is provided on the outer surface of one end of the mandrel body, which mates with the internal thread; A stop plate is sleeved on the other end of the mandrel body and located below the furnace wall plate. It is used to limit the depth of the mandrel body entering the limiting sleeve. The outer circumferential dimension of the stop plate is larger than the inner circumferential dimension of the limiting sleeve. The second nut is threaded to the other end of the mandrel body and is located below the stop end plate.

2. The furnace tube limiting device for an industrial furnace according to claim 1, characterized in that, The limiting sleeve includes: The casing body is cylindrical; The connecting plate is ring-shaped and is sleeved on the outer periphery of the sleeve body.

3. The furnace tube limiting device for an industrial furnace according to claim 2, characterized in that, The furnace wall panel has a sleeve connection hole, the sleeve body is inserted into the sleeve connection hole, the connecting plate is welded to the lower surface of the furnace wall panel, and the outer diameter of the connecting plate is 40-100mm larger than the diameter of the sleeve connection hole.

4. The furnace tube limiting device for an industrial furnace according to claim 1, characterized in that, It also includes a cap, which is detachably connected to the bottom end of the limiting sleeve when the fixing mandrel is removed from the limiting sleeve, and the cap can seal the bottom end of the limiting sleeve.

5. The furnace tube limiting device for an industrial furnace according to claim 4, characterized in that, The cap includes a disc portion, a first nut is provided at the center of one side of the disc portion, and a cylindrical portion is provided on the other side of the disc portion. One end of the cylindrical portion is connected to the outer periphery of the disc portion, and the other end of the cylindrical portion is provided with a plurality of plate-shaped teeth, which are formed by bending from the outer wall of the cylindrical portion toward the interior of the cylindrical portion.

6. The furnace tube limiting device for an industrial furnace according to claim 5, characterized in that, The bottom end of the limiting sleeve is provided with an annular groove, and multiple notches that cooperate with the plate-shaped teeth are opened on the groove wall on the side away from the furnace wall plate.

7. The furnace tube limiting device for an industrial furnace according to claim 1, characterized in that, The furnace tube extension tube includes: The reinforcing joint is a variable cross-section structure with a large cross-section at one end and a small cross-section at the other end. The large cross-section end of the reinforcing joint is used to connect with the lower elbow, and the small cross-section end of the reinforcing joint is connected with the extension pipe body.

8. An industrial furnace, characterized in that, include: The furnace tubes are arranged in a serpentine pattern inside the industrial furnace; Multiple furnace tube limiting devices for industrial furnaces according to any one of claims 1-7.

9. The industrial furnace according to claim 8, characterized in that, The furnace tube includes multiple straight tubes arranged parallel to each other in a vertical direction. The upper and lower ends of the straight tubes are connected to the adjacent straight tubes through upper and lower elbows to form a serpentine shape. The upper end of the furnace tube is fixed inside the industrial furnace by a hanging device. The bottom of the industrial furnace is provided with a furnace wall plate. Multiple limiting sleeves are inserted into the furnace wall plate. The other end of the furnace tube extension tube of each furnace tube limiting device is connected to a lower elbow.

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