Superheated steam cracking furnace

Abstract

The invention relates to a superheated steam cracking furnace, belongs to the technical field of waste resource recycling, and solves the problems that existing cracking equipment is low in treatment efficiency, a furnace tube of the cracking furnace is easy to deform and the like. A superheated steam cracking furnace comprises a furnace tube which is connected with a supporting frame through a supporting system. The supporting system comprises a sliding supporting unit and a sliding hanging unit; the furnace tube comprises a transmission shaft, a furnace shell arranged on the periphery of the transmission shaft in a sleeving mode, a first end cover and a second end cover, one end of the furnace tube is fixedly connected with the supporting frame through a first end cover and a fixing assembly, the other end is slidably connected with the supporting frame through a sliding supporting unit, and the middle of the furnace tube is connected with the frame through a sliding hanging unit. And the problem of deformation of the large-size or long furnace tube under the high-temperature working condition is avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of waste resource recycling, in particular to a superheated steam cracking furnace. Background Art

[0002] Thermal cracking is the most environmentally friendly technology for solid waste treatment, with dioxin emissions at only 10%-20% of incineration. Developed countries are increasingly adopting thermal cracking for high-pollution solid wastes such as medical waste, waste tires, and chlorine-containing plastics. However, traditional thermal cracking technology faces numerous challenges in solid waste treatment. First, because thermal cracking is an endothermic reaction, it has low efficiency and is difficult to scale up. Furthermore, different substances decompose at different temperatures, meaning existing equipment can typically only process a single substance and struggles to adapt to complex mixed solid wastes. Second, thermal cracking struggles to completely decompose substances with poor thermal conductivity, resulting in poor quality products such as oil, gas, and carbon black, which in turn affects its economic viability. Furthermore, the thermal cracking process generates large amounts of combustible gases and fuel oil, which can easily cause explosions and other safety hazards if leaks or sealing problems occur. Finally, existing cracking equipment suffers from low efficiency and high investment and operating costs. High temperatures cause significant thermal expansion and a loss of metal strength in the cracking furnace tubes, which can easily lead to mid-tube collapse and permanent deformation. Summary of the Invention

[0003] In view of the above analysis, the embodiments of the present invention are intended to provide a superheated steam cracking furnace to solve at least one of the problems existing in existing cracking equipment, such as low processing efficiency, high investment and operating costs, single processing material, easy deformation of cracking furnace tubes, and poor sealing at both ends of the drive shaft.

[0004] In one aspect, an embodiment of the present invention discloses a superheated steam cracking furnace, comprising a furnace tube connected to a support frame via a support system; the support system comprises a sliding support unit and a sliding suspension unit;

[0005] The furnace tube includes a transmission shaft, a furnace shell sleeved on the outer periphery of the transmission shaft, and a first end cover and a second end cover installed at both ends of the furnace shell;

[0006] One end of the furnace tube is fixedly connected to the support frame through a first end cover and a fixing assembly, the other end is slidably connected to the support frame through a sliding support unit, and the middle part of the furnace tube is connected to the frame through a sliding hanging unit.

[0007] Specifically, the transmission shaft includes an inner tube and an outer tube.

[0008] Furthermore, at least one stirring assembly is installed axially on the outer periphery of the outer tube.

[0009] Illustratively, each stirring assembly includes two 180° split clamping sleeves, which are symmetrically fastened to form a complete annular structure, and are radially fixed by bolts through connecting ears extending from both ends of the clamping sleeves; the clamping sleeves include a first clamping sleeve and a second clamping sleeve.

[0010] Preferably, two stirring pieces are arranged circumferentially symmetrically on each of the first clamping sleeves, and a single stirring piece includes a main body and a shovel head, and the central axes of the two stirring pieces are at a fixed angle of 120°; the center lines of the main bodies of the two stirring pieces on the same first clamping sleeve are distributed at a circumferential angle of 90°, and the center line of the main body of each stirring piece maintains a phase angle of 30° with the center line of the adjacent connecting ear.

[0011] It should be noted that, each of the second clamping sleeves is provided with a stirring piece, and the center line of the main body of the stirring piece on the second clamping sleeve forms a phase angle of 90° with the center line of the connecting ear.

[0012] It is worth noting that the stirring pieces of adjacent stirring components are arranged with a phase difference of 1° to 45°.

[0013] Furthermore, the furnace shell is provided with a heating assembly, including any one of an electromagnetic induction system or a resistance heating system.

[0014] Exemplarily, the furnace tube also includes a first top feed port, a first bottom drop port, a first superheated steam inlet, a second superheated steam inlet and a first oil and gas outlet. The first top feed port is located at the top of the connection end between the furnace tube and the sliding support unit, and the first bottom drop port and the first oil and gas outlet are respectively located at the bottom and top of the fixed connection end between the furnace tube and the frame; the first superheated steam inlet is located at the top of the furnace tube feed section; the second superheated steam inlet is located at the top of the middle section of the furnace tube.

[0015] On the other hand, an embodiment of the present invention further discloses an electronic waste cracking processing system, comprising the above-mentioned superheated steam cracking furnace.

[0016] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0017] 1. The cracking furnace tubes of the present invention achieve adaptive compensation for axial and radial expansion displacement of the tubes under high-temperature operating conditions through the synergistic effect of sliding support units and elastic suspension units. This design simultaneously meets the dual requirements of rigid support and elastic buffering. This releases radial and axial stresses in large or long tubes, preventing tube deformation. This combined design allows for localized free deformation, addressing the uneven axial temperature distribution of the tubes, thereby avoiding constraints on the overall structure.

[0018] 2. The drive shaft of the present invention utilizes a dual-tube structure. A circulating cooling medium is passed through the inner tube to maintain a suitable operating temperature. Insulating material is placed between the inner and outer tubes. This ensures that the outer tube maintains a high temperature that matches the operating temperature of the cracking furnace, avoiding unnecessary heat loss while also ensuring the cooling effect of the inner tube. To address the resulting thermal expansion problem of the inner and outer tubes, a composite structure is employed: one end is fixedly connected and the other end is slidably connected via a guide support ring. The fixed end ensures stable torque transmission, while the sliding connection allows relative axial displacement of the inner and outer tubes, adaptively compensating for differential expansion caused by temperature differences. This ensures reliable operation of the transmission system while addressing the thermal deformation coordination issue of the dual-tube structure in high-temperature environments.

[0019] 3. The present invention has significant advantages in adopting multiple groups of stirring components with phase difference arrangement. First, the use of discrete stirring piece structure reduces the starting torque, and the design of independently replaceable stirring components reduces maintenance costs; secondly, the split clamping sleeve design allows thermal expansion displacement, solves the problem of thermal deformation compensation, and is particularly suitable for high-temperature working conditions; secondly, the split clamping sleeve design can conveniently realize the dynamic adjustment of the number of stirring pieces along the axial direction of the reactor according to the material reaction stage through the combination of different clamping sleeves (such as the feed port adopts a 90° cross 4-piece layout), combined with the phase difference between adjacent stirring components and the shovel head angle design, to achieve more efficient radial material mixing, eliminate the flow dead zone problem, and significantly improve the material heating uniformity.

[0020] In the present invention, the above-mentioned technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of the present invention will be described in the following description, and some advantages will become apparent from the description or be learned through practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the contents particularly pointed out in the description and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like parts throughout the drawings.

[0022] Figure 1 This is a radial view of the superheated steam cracking furnace of the present invention;

[0023] Figure 2 This is an axial view of a superheated steam cracking furnace tube of the present invention;

[0024] Figure 3 For the present invention Figure 2 Middle DD section view;

[0025] Figure 4 For the present invention Figure 3 A partial enlarged view of the middle part;

[0026] Figure 5 For the present invention Figure 3 A partial enlarged view of point B in the middle;

[0027] Figure 6 For the present invention Figure 3 A partial enlarged view of point C in the middle;

[0028] Figure 7 This is a three-dimensional diagram of the multi-stage superheated steam cracking furnace of the present invention;

[0029] Figure 8 This is an axial view of a furnace tube of a multi-stage superheated steam cracking furnace according to the present invention;

[0030] Figure 9 For the present invention Figure 8 Middle EE section view;

[0031] Figure 10 A three-dimensional diagram of a sliding support unit according to the present invention;

[0032] Figure 11 This is an axial view of the sliding support unit of the present invention;

[0033] Figure 12 This is a three-dimensional diagram of the first roller of the present invention;

[0034] Figure 13 This is a three-dimensional diagram of the sliding suspension unit of the present invention;

[0035] Figure 14 This is an axial view of the sliding suspension unit of the present invention;

[0036] Figure 15 This is a radial view of the sliding suspension unit of the present invention;

[0037] Figure 16 A three-dimensional diagram of the transmission shaft of the present invention;

[0038] Figure 17 This is a three-dimensional diagram of the inner tube of the transmission shaft of the present invention;

[0039] Figure 18 A three-dimensional diagram of the guide support ring of the present invention;

[0040] Figure 19 This is an axial view of the assembly relationship between the guide support ring and the outer tube of the present invention;

[0041] Figure 20 This is an axial view of the assembly relationship between the guide support ring, the outer tube and the second spiral drive shaft head of the present invention;

[0042] Figure 21 A three-dimensional diagram of the support ring of the present invention;

[0043] Figure 22A three-dimensional diagram of the central axis connecting the water pipe of the present invention;

[0044] Figure 23 A perspective view of the stirring assembly of the present invention;

[0045] Figure 24 This is an axial view of the stirring assembly of the present invention;

[0046] Figure 25 This is a radial view of the assembly relationship between the stirring assembly and the transmission shaft of the present invention;

[0047] Figure 26 This is a three-dimensional diagram of the assembly relationship between the stirring assembly and the transmission shaft of the present invention;

[0048] Figure 27 This is a flow chart of the electronic waste cracking and processing system of the present invention.

[0049] Reference numerals:

[0050] 1-support frame; 2-furnace tube; 3-blocking ring;

[0051] 4 - drive shaft; 401 - inner tube; 402 - outer tube; 403 - guide support ring; 404 - axial rib; 405 - latch; 406 - support ring; 407 - first spiral drive shaft head; 408 - first water inlet furnace pipe; 409 - middle shaft connecting water pipe; 410 - first connecting pipe; 411 - middle main body; 412 - second connecting pipe; 413 - second water inlet furnace pipe; 414 - second spiral drive shaft head;

[0052] 5-furnace shell; 6-first end cover; 7-second end cover;

[0053] 8-sliding support unit; 801-slide rail support beam; 802-first guide rail; 803-first roller; 804-first connecting plate; 805-base; 806-support column; 807-arc bracket;

[0054] 9-connecting shaft; 10-L-shaped slide rail connecting plate;

[0055] 11 - Sliding lifting unit; 1101 - Second guide rail; 1102 - Second roller; 1103 - Second connecting plate; 1104 - Rectangular lifting plate; 1105 - Vertical connecting rod; 1106 - Compression spring; 1107 - Lifting crossbar; 1108 - Middle lifting ring tube; 1109 - Lifting column; 1110 - Lifting ring; 1111 - Lifting eyebolt;

[0056] 12-Fixed flange;

[0057] 13-first bearing unit; 1301-first connecting portion; 1302-first bearing seat; 1303-thrust bearing; 1304-first radial bearing; 1305-first dynamic seal assembly; 1306-second dynamic seal assembly; 1307-first oil seal assembly; 1308-first water cooling assembly;

[0058] 14 - second bearing unit; 1401 - second connecting portion; 1402 - second bearing seat; 1403 - second radial bearing; 1404 - third dynamic seal assembly; 1405 - fourth dynamic seal assembly; 1406 - second oil seal assembly; 1407 - second water cooling assembly; 1411 - axial sliding space;

[0059] 15-first rotating water pipe; 16-second rotating water pipe;

[0060] 17 stirring assembly; 1701 - first clamping sleeve; 1702 - stirring piece; 1703 - stirring piece body; 1704 - shovel head; 1705 - connecting ear;

[0061] 18-first top feed port; 19-first bottom feed port; 20-first superheated steam inlet; 21-second superheated steam inlet; 22-first oil and gas outlet;

[0062] 23 - Second support frame; 24 - Upper furnace tube; 2401 - Second bottom blanking port; 2402 - Second oil and gas outlet; 2403 - Third oil and gas outlet; 2404 - Third superheated steam inlet; 2405 - Fourth superheated steam inlet; 25 - Lower furnace tube; 2501 - Second top feed port; 2502 - Fourth oil and gas outlet; 2503 - Fifth superheated steam inlet; 2504 - Sixth superheated steam inlet; 26 - Oil and gas connecting assembly; 27 - Transition connection chamber; 28 - Blanking assembly;

[0063] A1 - raw material feeding belt; A2 - parts storage bin; A3 - crushing device; A4 - crushed material conveyor belt; A5 - crushed material buffer bin; A6 - crushed material spiral conveyor belt;

[0064] B1-superheated steam cracking furnace;

[0065] C1-Oil and gas catalytic reactor; C2-Oil and gas processor; C3-Oil-water separator;

[0066] D1-water-cooled conveyor; D2-solids sorting and storage tank; D3-solids conveyor belt;

[0067] E1-circulating cooling unit; F1-exhaust gas purification unit; G1-wastewater treatment unit. DETAILED DESCRIPTION

[0068] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, and are not used to limit the scope of the present invention.

[0069] The tube length of existing cracking furnaces is generally less than 10 meters, mainly due to two technical bottlenecks: First, under high-temperature conditions of 900°C, tubes longer than 10 meters will experience significant thermal expansion and a decrease in metal strength, leading to collapse and permanent deformation in the middle of the tube. Second, the cracking furnace's drive and stirring devices face the problem of thermal expansion differences between the drive shaft's temperature limit (500-600°C) and the high temperature of the tube (900°C), which not only causes axial / radial displacement conflicts but also leads to the risk of sealing interface failure. These limitations have forced the industry to adopt a multi-stage short-path reactor solution in series to ensure cracking efficiency. Although this avoids the technical risks of long tubes, it increases system complexity and energy efficiency losses.

[0070] On the one hand, a specific embodiment of the present invention discloses a superheated steam cracking furnace B1, such as Figures 1 to 3 As shown, it includes a furnace tube, and the furnace tube is connected to the support frame through a support system;

[0071] The support system includes a sliding support unit 8 and a sliding suspension unit 11;

[0072] The furnace tube 2 includes a transmission shaft 4, a furnace shell 5 sleeved on the outer periphery of the transmission shaft, and a first end cover 6 and a second end cover 7 installed at both ends of the furnace shell 5;

[0073] One end of the furnace tube 2 is fixedly connected to the support frame 1 through the first end cover 6 and the fixing assembly, and the other end is slidably connected to the support frame 1 through the sliding support unit 8. The middle part of the furnace tube is connected to the support frame 1 through the sliding suspension unit 11.

[0074] The furnace tubes of existing cracking furnaces are generally less than 10 meters long, resulting in insufficient residence time for the cracking reaction and low efficiency. To improve production capacity and energy efficiency, it is urgent to develop large-size or long furnace tube technology to extend the raw material reaction time and increase the cracking yield. However, large-size or long furnace tubes will produce significant axial and radial expansion due to heat, which will cause furnace tube deformation, weld cracking or support structure failure.

[0075] This invention utilizes a three-in-one support structure: a fixed end, a sliding support, and an elastic suspension joint. The fixed end provides a stable base for the furnace tube, suppressing overall swing under high-temperature conditions. A lower sliding support is provided at the free end to compensate for axial displacement and support gravity. A multi-degree-of-freedom elastic suspension joint system is deployed in the middle to achieve controllable radial cushioning and vibration absorption. This triple synergistic mechanism of fixed-end positioning constraint, sliding-end axial compensation, and elastic suspension joint radial cushioning effectively releases thermal stress and prevents tube deformation. This allows cracking furnace tubes to be larger than 10 meters in size and maintain long-term stable operation at 900°C without tube deformation or weld cracking.

[0076] In a possible design, the fixing component is a fixing flange 12 .

[0077] Specifically, if Figures 10 to 12 As shown, the sliding support unit 8 is installed on the lower side of the furnace tube 2, and includes a first sliding support assembly and a furnace tube supporting assembly installed thereon;

[0078] The first sliding support assembly includes a guide rail base and a first connecting plate laterally spanning the guide rail base;

[0079] The guide rail base includes two parallel slide rail support beams 801 symmetrically arranged on the frames on both sides of the furnace tube. Each slide rail support beam 801 is provided with a first guide rail 802, and each first guide rail 802 is installed with two or more first rollers 803. The first roller 803 is provided with a connecting shaft 9 on the side facing the furnace tube 2. The connecting shaft 9 is fixedly connected to the vertical connecting surface of the L-shaped slide rail connecting plate 10 by a locking nut. The horizontal connecting surface of the L-shaped slide rail connecting plate 10 extends longitudinally along the slide rail support beam.

[0080] The two ends of the first connecting plate 804 are respectively fixedly mounted on the upper surface of the horizontal connecting surface of the L-shaped connecting plate 10 on the same side and are perpendicular to the two first guide rails 802;

[0081] The furnace tube support assembly includes a base 805 installed parallel to the upper surface of the first connecting plate, two support columns 806 installed vertically at both ends of the base 805, and an arc-shaped bracket 807 spanning the top of the two support columns 806. The outer arc bottom of the arc-shaped bracket 807 is connected to the base, and the curvature of the inner arc surface matches the outer diameter of the furnace tube.

[0082] The lower sliding support adopts a low-friction guide rail roller mechanism. When the furnace tube is heated and elongated, it pushes the roller to slide along the guide rail to prevent the furnace tube from being compressed or stretched. The slide rail support beam and roller structure can withstand large vertical loads while ensuring axial sliding. The arc-shaped bracket fits the furnace tube, providing stable support and preventing sagging.

[0083] Furthermore, if Figures 13 to 15As shown, the sliding sling unit includes a second sliding support assembly and an elastic sling assembly;

[0084] The second sliding support assembly includes a second guide rail base fixed to the upper support frame of the furnace tube and a second connecting plate 1103 spanning the second guide rail base;

[0085] The second guide rail base includes two parallel second guide rails 1101 symmetrically mounted on the frames on both sides of the furnace tube, with two or more second rollers 1102 mounted on each second guide rail 1101; a connecting shaft 9 is provided on the side of the second roller 1102 facing the furnace tube, and the connecting shaft 9 is fixedly connected to the vertical connecting surface of the L-shaped slide rail connecting plate 10 via a nut, and the horizontal connecting surface of the L-shaped slide rail connecting plate 10 extends longitudinally along the second guide rails 1101; the second connecting plate 1103 is a transverse bridge member, and its two ends are respectively fixedly mounted on the lower surface of the horizontal connecting surface of the L-shaped connecting plate on the same side and are perpendicular to the two second guide rails 1101;

[0086] The elastic suspension assembly includes a suspension part and a floating support part from top to bottom;

[0087] The suspension portion includes a rectangular hanging plate 1104, four vertical connecting rods 1105 and four groups of compression springs 1106; the rectangular hanging plate 1104 is located above and parallel to the second connecting plate 1103, and a through hole is provided at each of the four corners of the rectangular hanging plate 1104. The upper ends of the four vertical connecting rods 1105 pass through the through holes of the hanging plate 1104 and are fixed by nuts. The lower ends of the vertical connecting rods 1105 pass through the second connecting plate 1103 and are connected to the floating support portion; the four groups of compression springs 1106 are respectively sleeved on the vertical connecting rods 1105 and pre-pressed between the hanging plate 1104 and the second connecting plate 1103 to form an elastic support;

[0088] The floating support comprises two horizontal suspension bars 1107 arranged axially along the furnace tube and located on either side of the furnace tube 2, and a central suspension ring tube 1108. The ends of the horizontal suspension bars 1107 are hingedly connected to the lower end of the vertical connecting rod 1105 via eyebolts 1111. The central suspension ring tube 1108 comprises an arc portion covering the bottom of the furnace tube and two upwardly extending suspension columns 1109. The tops of the suspension columns 1109 are loosely fitted onto the middle of the horizontal suspension bars 1107 via suspension rings 1110, forming a floating support. The hinged and loosely fitted eyebolt design of the floating support further relieves local deformation stress caused by uneven temperature distribution while maintaining necessary constraints, achieving a balance between overall stability and local flexibility.

[0089] In a possible design, more than one set of sliding suspension units 11 are provided.

[0090] The elastic suspension unit is constructed into a composite support system with multi-degree-of-freedom compensation capability by combining the second sliding support component with the elastic suspension component: the double guide rail-roller mechanism and the L-shaped connecting plate in the second sliding support component constitute a rigid sliding mechanism, which constrains the lateral displacement of the furnace tube and realizes axial sliding compensation, ensuring that the furnace tube can move smoothly along the guide rail when heated and elongated; the elastic suspension component realizes three-dimensional compensation by a combination of compression springs and floating hinged structures: the suspension part adopts four groups of symmetrically arranged pre-stressed spring groups, which provide flexible support in the vertical direction through adjustable spring pre-stress, absorbing vibration energy while avoiding the gravity sagging of the furnace tube; the floating support part is hinged by the lifting eye bolt and the clearance fit lifting eye, allowing controllable micro-displacement when the furnace tube expands radially; the hinged cooperation of the suspension cross bar and the connecting rod forms a passive adjustment mechanism. When the furnace tube is heated unevenly, the clearance fit between the lifting eye and the cross bar realizes local posture adaptive adjustment, which not only maintains the overall stability but also effectively avoids the stress concentration caused by rigid constraints.

[0091] The specific synergistic effects of the second sliding support assembly and the elastic suspension assembly include: the second connecting plate acts as a rigid bridge to synchronize the movement of the guide rails on both sides, while providing a stable mounting base for the elastic suspension assembly below; while the elastic suspension assembly absorbs radial thermal stress, its spring-connecting rod system symmetrically arranged at the four corners transfers the load evenly to the guide rails on both sides through the second connecting plate, avoiding unilateral overload; it not only ensures the guiding accuracy during axial sliding, but also gives the system radial floating ability, so that the complex thermal deformation of the furnace tube under high-temperature conditions can be fully compensated.

[0092] Furthermore, if Figure 16 、 Figure 17 As shown, the transmission shaft 4 is an inner and outer double-tube structure, and the transmission shaft 4 includes an inner tube 401 and an outer tube 402 . One end of the inner tube 401 and the outer tube 402 are fixedly connected, and the other end is slidably connected.

[0093] In a possible design, the inner tube 401 and the outer tube 402 are fixedly connected at one end by a latch 405 , and are slidably connected at the other end by a guide support ring 403 .

[0094] Exemplarily, the transmission shaft further comprises a first bearing unit 13 and a second bearing unit 14 at both ends. The second end cover 7 is located at the side where the furnace tube and the frame 1 are slidably connected. Preferably, the second end cover 7 is connected to the furnace tube and the second bearing unit 14 via a flange.

[0095] Specifically, if Figures 18 to 20 As shown, the inner wall of the guide support ring 403 is sleeved onto the outer side of the inner tube 401. A plurality of axial ridges 404 are evenly distributed around the outer wall of the guide support ring 403. A corresponding axial groove is provided around the inner wall of the outer tube 402. The guiding cooperation between the ridges and grooves enables axial sliding while limiting circumferential rotation.

[0096] The guide support ring 403 forms a sleeve-fitting fit with the outer wall of the inner tube 401 through its inner wall. Meanwhile, the axial ridges 404 evenly distributed around the outer wall and the axial grooves around the inner wall of the outer tube 402 form a precision guide pair. In the axial direction, the sliding fit between the ridges 404 and the grooves allows the inner tube assembly (including the guide support ring 403) to freely move axially relative to the outer tube 402, effectively compensating for length changes caused by thermal expansion. In the circumferential direction, the meshing contact between the ridges 404 and the grooves forms a strict circumferential constraint, completely limiting the relative rotation between the inner tube 401 and the outer tube 402, thereby ensuring the stability of the force transmission path. This bidirectional motion control mechanism not only meets the axial freedom requirements under thermal expansion conditions, but also ensures structural rigidity during torque transmission.

[0097] It is worth noting that Figure 21 As shown, nano thermal insulation ceramics and / or thermal insulation cotton are filled between the inner tube 401 and the outer tube 402, and more than one support ring 406 is arranged along the axial direction; the support ring 406 is made of nano thermal insulation ceramics.

[0098] Preferably, the outer wall of the inner tube and the inner wall of the outer tube are both coated with high-temperature heat-insulating coating.

[0099] The drive shaft 4 utilizes a dual-tube structure. A circulating cooling medium is passed through the inner tube 401 to maintain a suitable operating temperature. Insulating material is placed between the inner and outer tubes 401 and 402. This ensures that the outer tube maintains a high temperature that matches the operating temperature of the cracking furnace, avoiding unnecessary heat loss while also ensuring the cooling effect of the inner tube. To address the resulting thermal expansion of the inner and outer tubes, a composite structure is employed: one end is fixedly connected and the other end is slidably connected via a guide support ring. The fixed end ensures stable torque transmission, while the sliding end allows relative axial displacement of the inner and outer tubes, adaptively compensating for differential expansion caused by temperature differences. This ensures reliable operation of the transmission system while addressing the thermal deformation coordination issue of the dual-tube structure in high-temperature environments.

[0100] Furthermore, the inner diameter of the support ring 406 is adapted to the outer diameter of the inner tube, and the outer diameter is adapted to the inner diameter of the outer tube. Conical chamfers are processed on both sides of the support ring. The large end of the cone matches the inner diameter of the outer tube, and the small end matches the outer diameter of the inner tube, achieving a smooth transition, avoiding stress concentration, reducing the risk of microcracks, and improving fatigue resistance.

[0101] Furthermore, if Figure 3 、 Figure 6 As shown, the inner tube 401 includes a first spiral drive shaft head 407, a first water inlet furnace pipe 408, a middle shaft water pipe 409, a second water inlet furnace pipe 413 and a second spiral drive shaft head 414 which are plugged in sequentially, wherein the first water inlet furnace pipe 408, the second water inlet furnace pipe 413 and the middle shaft water pipe 409 are fixedly connected along the circumference after being plugged in.

[0102] A composite support structure is formed between the inner tube 401 and the outer tube 402 through the nano-insulation ceramic support ring 406 arranged axially at intervals. The inner diameter of the support ring 406 is precisely matched with the outer wall of the inner tube 401, and the outer diameter is tightly fitted with the inner wall of the outer tube 402. The conical chamfer design on both sides (the large end matches the inner diameter of the outer tube, and the small end matches the outer diameter of the inner tube) realizes a smooth transition; the support ring 406 is sleeved on the outside of the combined inner tube composed of the first spiral drive shaft head 407, the first water inlet furnace pipe 408, the middle axis connecting water pipe 409, the second water inlet furnace pipe 413 and the second spiral drive shaft head 414, and together with the nano-insulation ceramics and / or insulation cotton filled between the tubes, it constitutes a three-dimensional insulation support system with axial thermal displacement compensation capability, and effectively disperses stress through the conical transition structure.

[0103] Preferably, if Figure 22 As shown, the middle axial water pipe 409 includes a middle main body 411 and a first connecting pipe 410 and a second connecting pipe 412 at both ends, which form an interference fit with the first and second water inlet furnace pipes. The outer diameter of the middle main body 411 is the same as the outer diameter of the water inlet furnace pipe to ensure the continuity of the flow channel.

[0104] In a possible design, the water inlet furnace pipe and the middle axial water connecting pipe 409 are plugged into each other and fixedly connected along the circumference by a pin 405.

[0105] The drive shaft adopts a segmented structure, which can effectively reduce the risk of overall deformation and vibration of the long shaft, and compensate for thermal expansion through flexible connections during high-speed rotation or temperature changes, thereby improving the stability and reliability of the transmission system.

[0106] Specifically, if Figure 4 As shown, the free end of the first spiral drive shaft head 407 passes through the first end cover 6 and is fixed in position by the first bearing unit 13 and the first end cover 6; the free end of the second spiral drive shaft head 414 passes through the second end cover 7 and is slidably connected to the second end cover 7 by the second bearing unit 14.

[0107] Exemplarily, the free end of the first spiral drive shaft head 407 is connected to the external water cooling system through the first rotating water pipe 15 ; the free end of the second spiral drive shaft head 414 is connected to the external water cooling system through the second rotating water pipe 16 .

[0108] Specifically, the first bearing unit 13 includes a first connecting portion 1301 fixedly connected to the first end cover 6, and a first bearing seat 1302 rigidly connected to the first connecting portion 1301;

[0109] A thrust bearing 1303 and a first radial bearing 1304 are sequentially arranged in the first bearing seat 1302 . The thrust bearing 1303 is located on the proximal end cover side, and the first radial bearing 1304 is located on the proximal end free end side of the shaft head.

[0110] A first dynamic sealing assembly 1305 and a second dynamic sealing assembly 1306 are respectively provided on both sides of the first radial bearing 1304 , wherein the first dynamic sealing assembly 1305 is located on the proximal cover side, and a first oil sealing assembly 1307 is provided on the outer ring of the first radial bearing 1304 .

[0111] The specific connection relationship between the free end of the first spiral drive shaft head 407 and the first bearing unit 13 is as follows: after the first spiral drive shaft head 407 passes through the first end cover 6, its axial position is fixed by the first bearing unit 13, wherein the first connecting portion 1301 of the first bearing unit 13 is rigidly fixed to the first end cover 6 and forms a support frame through the first bearing seat 1302; the first spiral drive shaft head 407 is bidirectionally positioned in the bearing seat by a thrust bearing 1303 (close to the end cover side) and a first radial bearing 1304 (close to the free end side), the thrust bearing 1303 bears axial load, and the first radial bearing 1304 constrains radial displacement; a first dynamic seal assembly 1305 (close to the end cover side) and a second dynamic seal assembly 1306 (close to the free end side) are respectively provided on both sides of the first bearing unit 13 to form a double dynamic seal, and at the same time, a first oil seal assembly 1307 configured on the outer ring of the first radial bearing 1304 realizes lubricating medium sealing; the free end of the first spiral drive shaft head 407 is connected to the external water cooling system through a first rotating water pipe 15.

[0112] Furthermore, if Figure 5 As shown, the second bearing unit 14 includes a second connecting part 1401 fixedly connected to the second end cover 7, and a second bearing seat 1402 rigidly connected to the second connecting part 1401; a second radial bearing 1403 is provided in the second bearing seat 1402, and a third dynamic sealing assembly 1404 and a fourth dynamic sealing assembly 1405 are respectively provided on both sides of the second radial bearing 1402, wherein the third dynamic sealing assembly 1404 is located on the proximal end cover side, and a second oil sealing assembly 1406 is provided on the outer ring of the second radial bearing 1403.

[0113] An axial sliding space 1411 is provided between the installation position of the third dynamic sealing assembly 1404 and the joint portion between the second water inlet furnace pipe 413 and the second spiral drive shaft head 414, allowing the second water inlet furnace pipe 413 and the inner pipe 401 to produce axial relative displacement in this interval.

[0114] The specific connection relationship between the free end of the second spiral drive shaft head 414 and the second bearing unit 14 is as follows: after the second spiral drive shaft head 414 passes through the second end cover 7, its axial position is slidably connected through the second bearing unit 14, wherein the second connecting portion 1401 of the second bearing unit 14 is rigidly fixed to the second end cover 7, and a support frame is formed by the second bearing seat 1402; the second spiral drive shaft head 414 is radially positioned and constrained in the bearing seat by the second radial bearing 1403, and a third dynamic sealing assembly 1 is provided on both sides of the bearing. 404 (near the end cover side) and the fourth dynamic sealing assembly 1405 (near the free end side) constitute a double dynamic seal, and at the same time, the second oil sealing assembly 1406 configured on the outer ring of the second radial bearing 1403 realizes the sealing of the lubricating medium; an axial sliding space 1411 is reserved between the third dynamic sealing assembly 1404 and the second water inlet furnace pipe 413 / spiral drive shaft head 414 joint, so that the second water inlet furnace pipe can be axially displaced relative to the inner tube 401; the free end of the second spiral drive shaft head 414 is connected to the external water cooling system through the second rotating water pipe 16.

[0115] It should be noted that a first water cooling assembly 1308 is provided on the outer periphery of the first bearing seat 1302 corresponding to the installation position of the thrust bearing 1303, comprising a coaxially surrounding first water cooling ring pipe and a first cooling water inlet and a first cooling water outlet connected thereto;

[0116] A second water-cooling assembly 1407 is provided on the periphery of the second bearing seat 1402, comprising a coaxially surrounding second water-cooling ring pipe and a second cooling water inlet and a second cooling water outlet connected thereto.

[0117] The cooling area of ​​the second water-cooling ring pipe 1408 covers the shaft section corresponding to the axial sliding space 1411 of the inner and outer tubes of the shaft.

[0118] The sealing cooling system of the present invention utilizes a collaborative design of multi-stage dynamic sealing and zoned directional cooling. Regarding sealing, the first bearing unit forms a triple seal protection system by disposing a first dynamic seal assembly on the thrust bearing side, a first and second dynamic seal assembly on each side of the radial bearing, and a first oil seal assembly on the outer ring of the radial bearing. The second bearing unit, on the other hand, forms a triple seal system by disposing a third and fourth dynamic seal assembly on each side of the radial bearing, which in combination with the second oil seal assembly. An axial sliding space is provided between the third dynamic seal assembly and the shaft head joint, achieving both improved sealing reliability and axial displacement compensation capability. Regarding cooling, a dual-circulation independent cooling system is employed. A first water-cooling assembly disposed on the periphery of the first bearing seat precisely cools the high-heat zone of the thrust bearing via a coaxially surrounding first water-cooling annular pipe. A second water-cooling annular pipe disposed on the periphery of the second bearing seat specifically covers the corresponding shaft section of the sliding space between the inner and outer shaft tubes. This significantly improves cooling efficiency and effectively prevents cross-contamination between cooling water and lubricating oil. This solves the sealing and cooling challenges faced under high temperature differences and large axial displacement conditions.

[0119] When the drive shaft rotates at high speeds, the sealing system achieves reliable protection through the synergistic effect of multi-stage dynamic sealing and axial compensation: the first dynamic sealing assembly on the thrust bearing side and the dual dynamic sealing assemblies on both sides of the radial bearing form a triple sealing barrier, which, together with the oil sealing assembly, constitutes a complete fluid barrier. At the same time, the axial sliding space design allows the sealing assembly to adaptively adjust in response to thermal expansion or mechanical displacement of the shaft system, maintaining stable sealing contact pressure while avoiding seal failure caused by axial movement. The elastic sealing structure automatically compensates for radial runout under high-speed conditions, and the multi-stage sealing rings sequentially attenuate the lubricating oil pressure gradient, ultimately completely blocking the leakage path through the oil sealing assembly, ensuring that the lubrication system is completely isolated from the external environment and achieving long-term sealing under high-speed and large axial displacement conditions.

[0120] The design of the sealing system of the present invention is coordinated with the sliding structure of the transmission shaft to achieve reliable operation under high-temperature conditions: a rigid sealing structure is adopted at the fixed end to ensure the stability of torque transmission, while the sliding end uses a floating dynamic sealing component to cooperate with the axial sliding space, so that the sealing system can adapt to the thermal expansion displacement of the transmission shaft; at the same time, a directional cooling system is integrated to control the temperature of key parts to maintain the sealing performance, and to ensure the smoothness of axial movement by cooling the sliding area, forming a complete rigid fixation-flexible sliding-dynamic sealing-precision cooling integrated solution, which effectively solves the problems of sealing failure and movement jamming that are prone to occur in traditional structures under high-temperature and large-displacement conditions.

[0121] Under high-temperature operating conditions, the superheated steam cracking furnace achieves effective absorption of thermal expansion and stress release through the multi-degree-of-freedom compensation collaborative working mechanism of the composite support system, the inner tube and the outer tube sliding support ends: when the furnace tube expands due to heat, the first bearing unit 13 at the fixed end provides a reference positioning, and the second bearing unit 14 at the free end allows the second spiral drive shaft head 414 to move axially through the axial sliding space 1411; at the same time, the first roller 803 of the lower sliding support unit slides smoothly along the first guide rail 802, driving the arc-shaped bracket 807 to follow the support, ensuring the free axial extension of the furnace tube; radial expansion is absorbed by the deformation of the compression spring 1106 of the elastic suspension system and the elastic yield of the nano-insulation ceramic support ring 406, and the intermediate suspension ring tube 1108 adapts to the radial deformation of the furnace tube; the rib-groove structure of the guide support ring 403 always maintains radial positioning accuracy during the axial sliding process, and the suspension hinge mechanism can compensate for the angular deflection of ±1.5°. The entire system achieves multi-degree-of-freedom compensation in the axial, radial and angular directions through the triple collaborative mechanism of "fixed end constraint-sliding end compensation-elastic suspension buffer".

[0122] Furthermore, if Figures 23 to 26 As shown, one or more stirring assemblies 17 are axially mounted on the outer periphery of the outer tube 402; each stirring assembly 17 includes two 180° split clamping sleeves, which are symmetrically fastened to form a complete annular structure, and are radially fixed by bolts through connecting ears 1705 extending from both ends of the clamping sleeves; the clamping sleeves include a first clamping sleeve 1701 and a second clamping sleeve.

[0123] Preferably, two stirring blades 1702 are arranged circumferentially symmetrically on each first clamping sleeve 1701. Each stirring blade comprises a stirring blade body 1703 and a shovel head 1704, the central axes of which form a fixed angle of 120°. The centerlines of the two stirring blade bodies on the same first clamping sleeve are arranged at a 90° circumferential angle, and the centerline of each stirring blade body maintains a 30° phase angle with the centerline of the adjacent connecting ear 1705. It is understood that on a single first clamping sleeve, the circumferential angle between the centerline of the stirring blade body and the centerline of the adjacent connecting ear is 30°.

[0124] Exemplarily, one stirring piece is arranged on each of the second clamping sleeves, and the center line of the main body of the stirring piece on the second clamping sleeve forms a phase angle of 90° with the center line of the connecting ear.

[0125] The two first clamping sleeves are buckled together to form a stirring assembly including 4 stirring pieces, the two second clamping sleeves are buckled together to form a stirring assembly including 2 stirring pieces, and one first clamping sleeve and one second clamping sleeve are buckled together to form a stirring assembly including 3 stirring pieces; preferably, a stirring assembly with an appropriate number of stirring pieces is selected according to the material type and the different reaction stages of the furnace tube.

[0126] Preferably, the axial spacing between adjacent stirring components is ≥200 mm.

[0127] It is worth noting that the transmission shaft is provided with a material blocking ring 3 between the first end cover, the second end cover and the stirring assembly to prevent material leakage in the axial direction.

[0128] Furthermore, the stirring pieces of adjacent stirring components are arranged with a phase difference of 1° to 45°, that is, the pushing angle is 1° to 45°. It can be understood that in two adjacent groups of stirring components, the stirring pieces at the same position are staggered by 1° to 45° in the circumferential direction, which can effectively avoid dead zones in material flow and achieve continuous stirring.

[0129] Compared with the traditional spiral drive method, the present invention adopts multiple groups of phase-difference arranged stirring components, which has significant advantages. First, the use of a discrete stirring piece structure reduces the starting torque, and the design of individually replaceable stirring components reduces maintenance costs; secondly, the split clamping sleeve design allows thermal expansion displacement, solves the problem of thermal deformation compensation, and is particularly suitable for high-temperature working conditions; secondly, the split clamping sleeve design can conveniently realize the dynamic adjustment of the number of stirring pieces along the axial direction of the reactor according to the material reaction stage through the combination of different clamping sleeves (such as the feed port adopts a 90° cross 4-piece layout), combined with the phase difference between adjacent stirring components and the shovel head angle design, to achieve more efficient radial material mixing, eliminate the flow dead zone problem, and significantly improve the uniformity of material heating.

[0130] Furthermore, the furnace shell 5 is provided with a heating assembly, including either an electromagnetic induction system or a resistance heating system; the electromagnetic induction system includes an electromagnetic induction tube surrounding the outer periphery of the furnace shell and a matching power supply; the resistance heating system includes a resistance heating sleeve covering the outer periphery of the furnace shell.

[0131] Preferably, the furnace tube may also adopt a combustion heating system, with a gas burner provided in the furnace tube and gas supplied for heating through an external gas pipeline.

[0132] Preferably, different heating systems can be used in combination, with the electromagnetic induction system and the resistance heating system working together to achieve rapid temperature increase, and the combustion heating system being used to maintain a steady-state operating condition.

[0133] For example, Figure 1 As shown, the furnace tube also includes a first top feed port 18, a first bottom drop port 19, a first superheated steam inlet 20, a second superheated steam inlet 21 and a first oil and gas outlet 22. The first top feed port 18 is located at the top of the connection end between the furnace tube and the sliding support unit 8, and the first bottom drop port 19 and the first oil and gas outlet 22 are respectively located at the bottom and top of the fixed connection end between the furnace tube and the frame 1; the first superheated steam inlet 20 is arranged at the top of the furnace tube feed section; the second superheated steam inlet 21 is arranged at the top of the middle section of the furnace tube.

[0134] The core goal of the superheated steam cracking furnace is to quickly heat up the furnace tubes. The electromagnetic induction tubes on the outer periphery of the furnace shell adopt a dense turn layout to ensure that the furnace shell temperature is stable at 900°C. A stirring assembly including four stirring blades and a pushing angle of 20° to 25° are used. The drive shaft rotates at a speed of 80-120 rpm to achieve uniform preheating of the material through rapid stirring. At this stage, because the material is not cracked, the superheated steam injection amount is less than 5% of the rated steam amount or no superheated steam is injected.

[0135] The rated steam volume is determined according to the type of material to be processed.

[0136] In the second half of the furnace tube, the material temperature rises to above 450°C and enters the cracking stage. The heat absorption demand decreases, so the number of turns of the electromagnetic induction tubes on the periphery of the furnace shell becomes sparse, and the furnace shell temperature is maintained at 850°C. A stirring assembly including 2 to 3 stirring pieces is used, and the material is pushed to the discharge port to enter the next stage of processing. At this stage, the superheated steam injection amount is 30% to 70% of the rated steam amount according to the material type.

[0137] The temperature of the superheated steam is above 500°C. When the temperature inside the furnace shell is above 800°C, the superheated steam reacts with carbon to generate a large amount of reducing mixed gas of hydrogen and carbon monoxide. The mixed gas flows in the opposite direction to the movement of the material and mixes with the cracked gas and the material in the feed section of the furnace tube to remove organic bromides in the cracked gas and at the same time increase the proportion of small molecule cracked oil in the cracked gas.

[0138] It should be noted that when the material being processed is a circuit board, a rated amount of superheated steam must be injected. The amount of superheated steam injected is adjusted according to the properties of the material. Materials that are difficult to crack or have a larger average particle size require more steam to achieve more complete cracking. The second half of the furnace tube is the material cracking zone, and the amount of superheated steam injected is greater than that in the material preheating zone of the feed section of the furnace tube. This increases the amount of carbon-water reaction and the proportion of hydrogen, which facilitates the removal of harmful substances and conditioning after mixing with the cracked gas.

[0139] The superheated steam cracking furnace of the present invention adopts a synergistic process of front-stage high-temperature cracking + back-stage steam thermal decomposition: the front-stage furnace tube is maintained at a high temperature of 900°C by electromagnetic induction heating, so that the material undergoes deep cracking to generate small-molecule hydrocarbons; superheated steam above 500°C is introduced into the back-stage furnace tube to react with the cracked carbon residue to produce a carbon-water reaction (C+H2O→CO+H2), thereby generating a large amount of high-temperature reducing gas (H2 / CO); this reducing gas flows back to the front-stage cracking zone, which, on the one hand, provides a reducing environment for the cracking reaction and inhibits the generation of harmful substances such as dioxins; on the other hand, H2 can participate in the dehalogenation reaction of the cracked gas, such as debromination, while CO can promote the secondary cracking of the cracked oil, thereby increasing the proportion of small-molecule components in the product, ultimately achieving an integrated synergistic effect of cracking, purification and conditioning, and significantly improving the cracking efficiency of the cracking furnace.

[0140] In one possible design, the furnace tubes process a temperature of 900°C, with superheated steam cracking:

[0141] PVC molecular structure [-CH2-CHCl-] n

[0142] Thermal decomposition: [-CH2]+[-CHCl-]

[0143] Decomposition displacement reaction:

[0144] C+H2O(g)→CO(g)+H2(g)

[0145] CHCl + H2 → HCl + C x H y

[0146] Preferably, the driving motor of the transmission shaft is installed on the fixed connection side between the furnace tube and the frame.

[0147] The specific embodiment of the present invention also discloses a multi-stage superheated steam cracking furnace, such as Figures 7 to 9 As shown, the multi-stage superheated steam cracking furnace includes an upper furnace tube 24 and a lower furnace tube 25 arranged vertically and parallel in a second support frame 23; the second bottom dropout port 2401 of the upper furnace tube 24 is connected to the second top feed port 2501 of the lower furnace tube through a dropout assembly 28, and the two are aligned in center on the vertical projection plane; the upper furnace tube 24 and the lower furnace tube 25 are fixedly connected to the second support frame 23 on the side that is interconnected, and are respectively matched with the second support frame through a sliding support unit 8, and the middle part of the upper furnace tube and the middle part of the lower furnace tube are connected to the second support frame 23 through a sliding suspension unit 11.

[0148] Specifically, the second support frame is a double-layer structure, including an upper frame and a lower frame; the upper frame carries the upper furnace tube and cooperates with the free end of the upper furnace tube through a sliding support unit; the lower frame carries the lower furnace tube and cooperates with the free end of the lower furnace tube through a sliding support unit.

[0149] The upper furnace tube 24 and the lower furnace tube 25 adopt the same furnace tube structure as the furnace tube 2. The second bottom blanking port 2401 of the upper furnace tube 24 is connected to the second top feed port 2501 of the lower furnace tube 25 through a blanking assembly 28, forming a continuous process flow. Preferably, the upper furnace tube 24 also includes a second oil and gas outlet 2402 located at the top of the fixed end of the upper furnace tube 24 and a third oil and gas outlet 2403 located in the axial middle of the upper furnace tube. The lower furnace tube 25 also includes a fourth oil and gas outlet 2502 located in the axial middle of the lower furnace tube. The fourth oil and gas outlet 2502 and the third oil and gas outlet 2403 are connected by an oil and gas connecting assembly 26. The oil and gas connecting assembly 26 includes an oil and gas port connecting pipe and a connecting pipe expansion joint that are connected to the furnace shell of the upper furnace tube. The furnace shell of the upper furnace tube is provided with an annular expanded diameter section at the connection with the oil and gas connecting assembly to form a transition connection cavity 27.

[0150] In one possible design, the fourth oil and gas outlet adopts a four-way structure, the first interface is connected to the lower furnace tube shell, the second interface is connected to the oil and gas connecting component, and the third interface and the fourth interface are respectively connected to the external oil and gas transmission pipeline.

[0151] Preferably, the blanking assembly 28 includes upper and lower furnace tube expansion joints.

[0152] The upper furnace tube also includes a third superheated steam inlet 2404 located at the top of the upper furnace tube feed section and a fourth superheated steam inlet 2405 located at the top of the middle section of the upper furnace tube; the lower furnace tube also includes a fifth superheated steam inlet 2503 located at the top of the lower furnace tube feed section and a sixth superheated steam inlet 2504 located at the top of the middle section of the lower furnace tube.

[0153] For difficult-to-process electronic waste, the use of a multi-stage superheated steam cracking furnace can provide a longer residence time and ensure a thorough reaction.

[0154] In a possible design, the second support frame includes an upper and lower rectangular frame having the same structure and being parallel to each other. The upper rectangular frame is used to fix the upper furnace tube, and the lower rectangular frame is used to fix the lower furnace tube.

[0155] Preferably, the superheated steam cracking furnace further includes a thermal insulation layer wrapped around the outer periphery of the frame.

[0156] On the other hand, a specific embodiment of the present invention also discloses an electronic waste cracking processing system, such as Figure 27 As shown, it includes a raw material processing unit, a continuous superheated steam thermal cracking unit connected to the raw material processing unit through a feeding unit, and an oil and gas processing unit and a discharge sorting unit respectively connected to the oil and gas output end and the solid output end of the superheated steam thermal cracking unit;

[0157] The continuous superheated steam cracking unit comprises a superheated steam cracking furnace B1 or a multi-stage superheated steam cracking furnace, a superheated steam distribution system and a gas heating system;

[0158] The superheated steam distribution system is located within the thermal insulation layer of the superheated steam cracking furnace and includes a first superheated steam preheating main pipe and a second superheated steam preheating main pipe surrounding the outer wall of the superheated steam cracking furnace; one end of the first steam preheating main pipe is connected to an external water supply or steam supply main pipe, and the other end is connected to the first steam inlet, the third steam inlet, and the fifth steam inlet via a pipeline; one end of the second steam preheating main pipe is connected to an external water supply or steam supply main pipe, and the other end is connected to the second steam inlet, the fourth steam inlet, and the sixth steam inlet via a pipeline;

[0159] The gas heating system comprises a burner connected to an external gas main.

[0160] When the continuous superheated steam cracking unit is in operation, raw materials enter the cracking furnace through the feeding unit; the gas system burns external gas through the burner to heat the furnace tube; and the waste heat of the flue gas in the furnace tube is used to heat the first superheated steam preheating main pipe and the second superheated steam preheating main pipe, so that the superheated steam temperature in the preheating main pipe is higher than 500° C. The cracking products in the cracking furnace include gaseous cracking gas and solid residue, wherein the gaseous cracking gas enters the subsequent oil and gas processing unit, and the solid residue enters the subsequent discharge and sorting unit.

[0161] Furthermore, the raw material processing unit includes a raw material feeding belt A1, a parts storage bin A2, a crushing device A3, a crushed material conveying belt A4, a crushed material buffer bin A5 and a crushed material spiral conveyor belt A6 which are connected in sequence.

[0162] Among them, the raw material feeding belt is a closed conveyor belt and is equipped with a magnetic separation device and a manual sorting station, which is used to separate transformers, coils and radiators, and the sorted materials are transported to the component storage bin; the crushing device is a fully enclosed crusher with metal separation, dust collection and material classification functions, and the crushed particle size is controlled within 20mm; the crushed material is transported to the crushed material buffer bin for temporary storage via the crushed material conveyor belt, and finally transported to the feeding system by the crushed material spiral conveyor belt.

[0163] Illustratively, the feed system includes an upper hopper, an upper feed sealing valve, a feed intermediate tank, a lower feed sealing valve, and a feed buffer tank, all connected in sequence. During operation, the lower feed sealing valve is closed, and material processed by the raw material processing unit is fed into the upper hopper via a crushing screw conveyor. The upper feed sealing valve is opened, allowing the material to enter the feed intermediate tank. The upper feed sealing valve is then closed, and nitrogen is introduced into the feed intermediate tank to completely replace the air in the tank. The lower feed sealing valve is then opened, allowing the material to enter the feed buffer tank.

[0164] The feeding system ensures that no oxygen penetrates into the superheated steam cracking unit and prevents air from entering the reaction furnace tube through alternating opening and closing of double valves and nitrogen protection, and realizes continuous closed feeding through the sealing valve group and nitrogen replacement.

[0165] Furthermore, the oil and gas processing unit includes an oil and gas outlet pipe, an oil and gas catalytic reactor C1, an oil and gas processor C2, an oil-water separator C3, and an oil purifier, all connected in sequence. The catalyst in the oil and gas catalytic reactor uses ceramic nickel iron. During operation, the high-temperature cracked gas from the continuous superheated steam cracking unit enters the oil and gas catalytic reactor through the oil and gas outlet pipe, is debrominated by the ceramic nickel iron catalyst, and then is separated and purified by the oil and gas processor before entering the oil-water separator. In the oil-water separator, the cracked gas is divided into light oil, gas, and wastewater. The gas is recycled for combustion and heat supply in the continuous superheated steam cracking unit, while the light oil is stored in an external oil tank. The oil and gas processing unit realizes resource utilization and harmless treatment of the cracked gas.

[0166] Preferably, the discharging and sorting unit includes a water-cooling conveying system and a sorting system connected in sequence.

[0167] Specifically, the water-cooled conveying system is connected to the solid output of the continuous superheated steam cracking unit and includes a discharge pipe, a water-cooled tank, a gate valve, an upper discharge sealing valve, an intermediate discharge tank, a lower discharge sealing valve, and a water-cooled conveyor D1, which are connected in sequence. The output of the water-cooled conveyor is connected to a sorting system. During operation, the high-temperature solid residue after the reaction enters the water-cooled tank through the discharge pipe for cooling. It then enters the intermediate discharge tank through the gate valve and the upper discharge sealing valve. Nitrogen is then injected into the intermediate discharge tank to replace the air in the tank. After the lower discharge sealing valve is opened, the material enters the water-cooled conveyor. The water-cooled conveying system utilizes a three-stage sealing and cooling design to ensure the safe discharge of high-temperature materials without gas leakage.

[0168] The feeding system and discharging system of the present invention adopt a double valve + nitrogen replacement sealing structure (upper sealing valve-intermediate tank-lower sealing valve), which solves the oxidation and safety risk problems caused by air infiltration during feeding / discharging of traditional cracking furnaces.

[0169] Exemplarily, the sorting system includes a solid sorting and storage tank D2 and a solid conveyor belt D3 connected to a water-cooled conveying system; the water-cooled conveying system sends the solid reaction product into the reaction solid sorting and storage tank for sorting, and then separates the metal from glass fiber, carbon black, etc. through the solid conveyor belt; the separated glass fiber, carbon black, etc. are sent to an external glass fiber and carbon black collection device for storage; the separated metal is briquette-pressed by a briquette machine for subsequent processing.

[0170] Furthermore, the e-waste pyrolysis system also includes a metal smelting unit, an exhaust gas purification unit F1, and a wastewater treatment unit G1. The metal smelting unit includes a metal smelting furnace. The briquetted metal enters the metal smelting furnace for smelting, and the exhaust gas generated during the smelting process enters the exhaust gas purification unit for purification. Preferably, the metal smelting furnace is a blast furnace, which can utilize this system to generate large amounts of fuel oil and gas, achieving resource recycling.

[0171] Preferably, the electronic waste cracking treatment system further comprises a circulating cooling unit E1, which provides circulating cooling water for the water cooling tank, dynamic equipment cooling and sealing of the electronic waste cracking treatment system.

[0172] Specifically, the electronic waste cracking and processing system also includes a control system.

[0173] Furthermore, the electronic waste cracking treatment system also includes: a temperature measurement system installed at the key nodes of the reactor, including at least three temperature measurement points: the furnace tube inlet, the cracking section, and the oil and gas outlet; a pressure measurement system distributed in the gas and solid phase pipelines, including a high-temperature resistant pressure sensor; the measurement system and control system adjust the cracking process parameters in real time.

[0174] Exemplarily, the operation process of the electronic waste cracking processing system is as follows:

[0175] Raw materials are loaded via a closed conveyor belt. After passing through a magnetic separator and manual sorting stations to separate the transformer, coil, and radiator, the sorted material is conveyed to a component storage bin. The remaining material enters a fully enclosed crusher for crushing, where metal separation, dust collection, and material classification are achieved, ensuring the crushed particle size is controlled within a specified range. The crushed material is then transported to a surge bin for temporary storage via a closed conveying system, and then fed into the feed system via a spiral conveyor belt. During feeding, the lower sealing valve is closed, and the material enters the feed intermediate tank through the upper sealing valve. The upper sealing valve is then closed, nitrogen is introduced to displace the air, and the lower sealing valve is opened to allow the material to enter the feed surge tank for final delivery to the cracking furnace.

[0176] During operation, the fuel gas system heats the furnace tubes with external fuel gas from burners. Simultaneously, waste heat from the flue gas in the furnace tubes heats the superheated steam system, bringing the superheated steam in the preheating main to the desired temperature. The cracking products are divided into gaseous cracked gas and solid residue. The gaseous cracked gas enters the subsequent oil and gas processing unit, while the solid residue passes through the discharge pipe into a water-cooled tank for cooling. It then passes through a gate valve and sealing valve system into the discharge intermediate tank. After nitrogen is filled to displace the air, the material enters a water-cooled conveyor. The water-cooled conveyor system utilizes a multi-stage sealing and cooling design to ensure the safe discharge of high-temperature materials without gas leakage.

[0177] The cooled solid residue is conveyed via a conveyor belt to a sorting system, where metal is separated from non-metallic materials such as glass fiber and carbon black in a reaction solids sorting and storage tank. The separated glass fiber and carbon black are then stored in an external collection device, while the metal is briquetted in a briquetting machine and transported to the metal smelting unit for smelting. Exhaust gas generated during the smelting process is treated in an exhaust gas purification unit, while the fuel and gas produced by the system are recycled. Furthermore, a circulating cooling unit provides circulating cooling water to the water-cooled tanks, motor cooling, and sealing systems, ensuring stable system operation.

[0178] It should be noted that the energy cycle design of the electronic waste cracking treatment system of the present invention includes the following: first, utilizing furnace tube flue gas waste heat recovery technology, through the first and second superheated steam main pipes arranged around the furnace body, the high-temperature flue gas waste heat is converted into superheated steam above 500°C, which is reused in the cracking reaction, thus achieving a primary energy cycle; second, after the flammable oil gas produced by cracking is treated by the purification unit, a portion of the high-quality gas is returned through a pipeline to the cracking furnace burner, serving as auxiliary fuel for supplementary heating, forming a secondary energy closed loop of cracking-purification-reuse; finally, the remaining purified gas is transported to the metal smelting furnace as the primary heat source, which not only meets the high temperature requirements of the smelting process but also realizes cross-system energy transfer from cracking products to smelting energy. This significantly improves the internal energy utilization rate of the system and effectively reduces dependence on external energy.

[0179] On the other hand, a specific embodiment of the present invention also discloses a method for improving the cracking efficiency of a cracking furnace, which is carried out in a superheated steam cracking furnace with a furnace tube length of ≥10m, wherein the furnace tube is divided into a feed section, a middle section and a discharge section, wherein the feed section accounts for 15%-20% of the total length of the furnace tube, and the middle section accounts for 50%-60%. Superheated steam is introduced into the furnace tube in sections, and the steam introduction amount in the feed section is controlled to be 0-8% of that in the middle section.

[0180] In summary, the present invention achieves comprehensive thermal deformation compensation and stable operation of a superheated steam cracking furnace under high-temperature conditions through a multi-system collaborative design. The furnace tubes utilize a composite structure of sliding support units and elastic suspension units. Through the ingenious combination of rigid guide rails and flexible suspension, they simultaneously address the requirements of axial sliding compensation and radial elastic support. The dual-tube drive shafts, with differentiated temperature control for the inner and outer tubes and a composite end connection mechanism, ensure torque transmission while adaptively compensating for thermal deformation. The sealing system integrates the advantages of rigid fixed ends and flexible sliding ends, and, in conjunction with directional cooling, provides dynamic sealing protection. Through the coordinated mechanism of "fixed constraint-sliding compensation-elastic buffering," these subsystems fully relieve axial and radial thermal stresses in large-sized furnace tubes under high temperatures. The transmission system maintains stable transmission under temperature differentials, and the sealing assembly adapts to large sliding displacements. This achieves multi-degree-of-freedom compensation for high-temperature equipment, effectively overcoming the technical bottlenecks of deformation, cracking, and seal failure that plague conventional cracking furnaces during long-term, high-temperature operation.

[0181] The superheated steam cracking furnace of the present invention is described in detail below with reference to specific embodiments.

[0182] Example 1

[0183] This embodiment provides a superheated steam cracking furnace.

[0184] A superheated steam cracking furnace, a superheated steam cracking furnace B1, comprising a furnace tube, the furnace tube having a length of 10 m, the furnace tube being connected to a supporting frame via a supporting system;

[0185] The support system includes a sliding support unit 8 and a sliding suspension unit 11;

[0186] The furnace tube 2 includes a transmission shaft 4, a furnace shell 5 sleeved on the outer periphery of the transmission shaft, and a first end cover 6 and a second end cover 7 installed at both ends of the furnace shell 5;

[0187] One end of the furnace tube 2 is fixedly connected to the support frame 1 through the first end cover 6 and the fixing assembly, and the other end is slidingly connected to the support frame 1 through the sliding support unit 8. The middle part of the furnace tube is connected to the support frame 1 through the sliding hanging unit 11; the fixing assembly is a fixing flange 12.

[0188] The sliding support unit 8 is installed on the lower side of the furnace tube 2, and includes a first sliding support assembly and a furnace tube supporting assembly installed thereon;

[0189] The first sliding support assembly includes a guide rail base and a first connecting plate laterally spanning the guide rail base;

[0190] The guide rail base includes two parallel slide rail support beams 801 symmetrically arranged on the frames on both sides of the furnace tube. Each slide rail support beam 801 is provided with a first guide rail 802, and each first guide rail 802 is installed with two or more first rollers 803. The first roller 803 is provided with a connecting shaft 9 on the side facing the furnace tube 2. The connecting shaft 9 is fixedly connected to the vertical connecting surface of the L-shaped slide rail connecting plate 10 by a locking nut. The horizontal connecting surface of the L-shaped slide rail connecting plate 10 extends longitudinally along the slide rail support beam.

[0191] The two ends of the first connecting plate 804 are respectively fixedly mounted on the upper surface of the horizontal connecting surface of the L-shaped connecting plate 10 on the same side and are perpendicular to the two first guide rails 802;

[0192] The furnace tube support assembly includes a base 805 installed parallel to the upper surface of the first connecting plate, two support columns 806 installed vertically at both ends of the base 805, and an arc-shaped bracket 807 spanning the top of the two support columns 806. The outer arc bottom of the arc-shaped bracket 807 is connected to the base, and the curvature of the inner arc surface matches the outer diameter of the furnace tube.

[0193] The sliding suspension unit includes a second sliding support assembly and an elastic suspension assembly;

[0194] The second sliding support assembly includes a second guide rail base fixed to the upper support frame of the furnace tube and a second connecting plate 1103 spanning the second guide rail base;

[0195] The second guide rail base includes two parallel second guide rails 1101 symmetrically mounted on the frames on both sides of the furnace tube, with two or more second rollers 1102 mounted on each second guide rail 1101; a connecting shaft 9 is provided on the side of the second roller 1102 facing the furnace tube, and the connecting shaft 9 is fixedly connected to the vertical connecting surface of the L-shaped slide rail connecting plate 10 via a nut, and the horizontal connecting surface of the L-shaped slide rail connecting plate 10 extends longitudinally along the second guide rails 1101; the second connecting plate 1103 is a transverse bridge member, and its two ends are respectively fixedly mounted on the lower surface of the horizontal connecting surface of the L-shaped connecting plate on the same side and are perpendicular to the two second guide rails 1101;

[0196] The elastic suspension assembly includes a suspension part and a floating support part from top to bottom;

[0197] The suspension portion includes a rectangular hanging plate 1104, four vertical connecting rods 1105 and four groups of compression springs 1106; the rectangular hanging plate 1104 is located above and parallel to the second connecting plate 1103, and a through hole is provided at each of the four corners of the rectangular hanging plate 1104. The upper ends of the four vertical connecting rods 1105 pass through the through holes of the hanging plate 1104 and are fixed by nuts. The lower ends of the vertical connecting rods 1105 pass through the second connecting plate 1103 and are connected to the floating support portion; the four groups of compression springs 1106 are respectively sleeved on the vertical connecting rods 1105 and pre-pressed between the hanging plate 1104 and the second connecting plate 1103 to form an elastic support;

[0198] The floating support part includes two hanging cross bars 1107 arranged along the axial direction of the furnace tube and respectively provided on both sides of the furnace tube 2, and an intermediate hanging ring tube 1108; the two ends of the hanging cross bar 1107 are hinged to the lower end of the vertical connecting rod 1105 through a hanging ring bolt 1111; the intermediate hanging ring tube 1108 includes an arc portion covering the bottom of the furnace tube and two hanging columns 1109 extending upward, and the top of the hanging column 1109 is sleeved on the middle position of the hanging cross bar 1107 in a clearance fit manner through a hanging ring 1110 to form a floating support.

[0199] The transmission shaft 4 is an inner and outer double-tube structure, comprising an inner tube 401 and an outer tube 402 . One end of the inner tube 401 and the outer tube 402 are fixedly connected by a latch 405 , and the other end is slidably connected by a guide support ring 403 .

[0200] The transmission shaft further comprises a first bearing unit 13 and a second bearing unit 14 at both ends. The second end cover 7 is located at the side where the furnace tube and the frame 1 are slidably connected. Preferably, the second end cover 7 is connected to the furnace tube and the second bearing unit 14 via a flange.

[0201] The inner wall of the guide support ring 403 is sleeved on the outer side of the inner tube 401, and its outer wall is evenly distributed with a number of axial ridges 404. The inner wall of the outer tube 402 is correspondingly provided with axial grooves. The guiding cooperation between the ridges and grooves realizes axial sliding function while limiting circumferential rotation.

[0202] Nano thermal insulation ceramics and / or thermal insulation cotton are filled between the inner tube 401 and the outer tube 402 , and one or more support rings 406 are arranged along the axial direction; the support rings 406 are made of nano thermal insulation ceramics.

[0203] The outer wall of the inner tube and the inner wall of the outer tube are both coated with high-temperature heat-insulating coating;

[0204] The inner diameter of the support ring 406 is adapted to the outer diameter of the inner tube, and the outer diameter is adapted to the inner diameter of the outer tube. The two sides of the support ring are processed with conical chamfers, the large end of the conical surface matches the inner diameter of the outer tube, and the small end matches the outer diameter of the inner tube.

[0205] The inner tube 401 includes a first spiral drive shaft head 407, a first water inlet furnace pipe 408, a middle shaft connecting water pipe 409, a second water inlet furnace pipe 413 and a second spiral drive shaft head 414, which are plugged in sequentially, wherein the first water inlet furnace pipe 408, the second water inlet furnace pipe 413 and the middle shaft connecting water pipe 409 are fixedly connected along the circumference after being plugged in.

[0206] The middle axial water pipe 409 includes a middle main body 411 and a first connecting pipe 410 and a second connecting pipe 412 at both ends, forming an interference fit with the first and second water inlet furnace pipes. The outer diameter of the middle main body 411 is the same as the outer diameter of the water inlet furnace pipe to ensure flow path continuity.

[0207] The free end of the first spiral drive shaft head 407 passes through the first end cover 6 and is fixed in position by the first bearing unit 13 and the first end cover 6; the free end of the second spiral drive shaft head 414 passes through the second end cover 7 and is slidably connected to the second end cover 7 by the second bearing unit 14.

[0208] The free end of the first spiral drive shaft head 407 is connected to the external water cooling system through the first rotating water pipe 15 ; the free end of the second spiral drive shaft head 414 is connected to the external water cooling system through the second rotating water pipe 16 .

[0209] The first bearing unit 13 includes a first connecting portion 1301 fixedly connected to the first end cover 6 and a first bearing seat 1302 rigidly connected to the first connecting portion 1301;

[0210] A thrust bearing 1303 and a first radial bearing 1304 are sequentially arranged in the first bearing seat 1302 . The thrust bearing 1303 is located on the proximal end cover side, and the first radial bearing 1304 is located on the proximal end free end side of the shaft head.

[0211] A first dynamic sealing assembly 1305 and a second dynamic sealing assembly 1306 are respectively provided on both sides of the first radial bearing 1304 , wherein the first dynamic sealing assembly 1305 is located on the proximal cover side, and a first oil sealing assembly 1307 is provided on the outer ring of the first radial bearing 1304 .

[0212] The second bearing unit 14 includes a second connecting part 1401 fixedly connected to the second end cover 7, and a second bearing seat 1402 rigidly connected to the second connecting part 1401; a second radial bearing 1403 is provided in the second bearing seat 1402, and a third dynamic sealing assembly 1404 and a fourth dynamic sealing assembly 1405 are respectively provided on both sides of the second radial bearing 1402, wherein the third dynamic sealing assembly 1404 is located on the proximal cover side, and a second oil sealing assembly 1406 is provided on the outer ring of the second radial bearing 1403.

[0213] An axial sliding space 1411 is provided between the installation position of the third dynamic sealing assembly 1404 and the joint portion between the second water inlet furnace pipe 413 and the second spiral drive shaft head 414, allowing the second water inlet furnace pipe 413 and the inner pipe 401 to produce axial relative displacement in this interval.

[0214] A first water cooling assembly 1308 is provided on the outer periphery of the first bearing seat 1302 at a position corresponding to the installation position of the thrust bearing 1303, including a first water cooling ring pipe coaxially surrounding the first water cooling ring pipe and a first cooling water inlet and a first cooling water outlet connected thereto;

[0215] A second water-cooling assembly 1407 is provided on the periphery of the second bearing seat 1402, comprising a coaxially surrounding second water-cooling ring pipe and a second cooling water inlet and a second cooling water outlet connected thereto.

[0216] The cooling area of ​​the second water-cooling ring pipe 1408 covers the shaft section corresponding to the axial sliding space 1411 of the inner and outer tubes of the shaft.

[0217] One or more stirring assemblies 17 are axially mounted on the outer periphery of the outer tube 402; each stirring assembly 17 comprises two 180° split clamping sleeves, which are symmetrically fastened to form a complete annular structure, and are radially fixed by bolts through connecting ears 1705 extending from both ends of the clamping sleeves; the clamping sleeves comprise a first clamping sleeve 1701 and a second clamping sleeve.

[0218] Each first clamping sleeve 1701 has two stirring blades 1702 arranged circumferentially symmetrically. Each stirring blade comprises a main portion 1703 and a shovel head 1704, with their central axes forming a fixed 120° angle. The centerlines of the two stirring blade main portions on the same first clamping sleeve are arranged at a 90° circumferential angle, and the centerline of each stirring blade main portion maintains a 30° phase angle with the centerline of the adjacent connecting lug 1705. It is understood that on a single first clamping sleeve, the circumferential angle between the centerline of the stirring blade main portion and the centerline of the adjacent connecting lug is 30°.

[0219] Each of the second clamping sleeves is provided with a stirring piece, and the center line of the main body of the stirring piece on the second clamping sleeve forms a phase angle of 90 degrees with the center line of the connecting ear.

[0220] The two first clamping sleeves are buckled together to form a stirring assembly including 4 stirring pieces, the two second clamping sleeves are buckled together to form a stirring assembly including 2 stirring pieces, and one first clamping sleeve and one second clamping sleeve are buckled together to form a stirring assembly including 3 stirring pieces; preferably, a stirring assembly with an appropriate number of stirring pieces is selected according to the material type and the different reaction stages of the furnace tube.

[0221] The transmission shaft is provided with a material blocking ring 3 between the first end cover, the second end cover and the stirring assembly to prevent material from leaking in the axial direction.

[0222] The stirring pieces of adjacent stirring components are arranged with a phase difference of 1° to 45°.

[0223] The furnace shell 5 is provided with a heating assembly, including either an electromagnetic induction system or a resistance heating system.

[0224] The furnace tube also includes a first top feed port 18, a first bottom drop port 19, a first superheated steam inlet 20, a second superheated steam inlet 21 and a first oil and gas outlet 22. The first top feed port 18 is located at the top of the connection end between the furnace tube and the sliding support unit 8, and the first bottom drop port 19 and the first oil and gas outlet 22 are respectively located at the bottom and top of the fixed connection end between the furnace tube and the frame 1; the first superheated steam inlet 20 is arranged at the top of the furnace tube feed section; the second superheated steam inlet 21 is arranged at the top of the middle section of the furnace tube.

[0225] The driving motor of the transmission shaft is installed on the fixed connection side of the furnace tube and the frame.

[0226] Example 2

[0227] This embodiment provides a multi-stage superheated steam cracking furnace.

[0228] A multi-stage superheated steam cracking furnace, comprising an upper furnace tube 24 and a lower furnace tube 25 arranged vertically and parallel in a second support frame 23; the second bottom blanking port 2401 of the upper furnace tube 24 is connected to the second top feed port 2501 of the lower furnace tube via a blanking assembly 28, and the centers of the two are aligned on a vertical projection plane; the upper furnace tube 24 and the lower furnace tube 25 are fixedly connected to the second support frame 23 on one side that is interconnected, and are respectively engaged with the second support frame via sliding support units 8, and the middle portions of the upper furnace tube and the lower furnace tube are both connected to the second support frame 23 via sliding suspension units 11.

[0229] The upper furnace tube 24 and the lower furnace tube 25 adopt the same furnace tube structure as the furnace tube 2. The second bottom blanking port 2401 of the upper furnace tube 24 is connected to the second top feed port 2501 of the lower furnace tube 25 through a blanking assembly 28, forming a continuous process flow. Preferably, the upper furnace tube 24 also includes a second oil and gas outlet 2402 located at the top of the fixed end of the upper furnace tube 24 and a third oil and gas outlet 2403 located in the axial middle of the upper furnace tube. The lower furnace tube 25 also includes a fourth oil and gas outlet 2502 located in the axial middle of the lower furnace tube. The fourth oil and gas outlet 2502 and the third oil and gas outlet 2403 are connected by an oil and gas connecting assembly 26. The oil and gas connecting assembly 26 includes an oil and gas port connecting pipe and a connecting pipe expansion joint that are connected to the furnace shell of the upper furnace tube. The furnace shell of the upper furnace tube is provided with an annular expanded diameter section at the connection with the oil and gas connecting assembly to form a transition connection cavity 27.

[0230] The fourth oil and gas outlet adopts a four-way structure, with the first interface connected to the lower furnace tube housing, the second interface connected to the oil and gas connecting component, and the third and fourth interfaces connected to external oil and gas delivery pipelines respectively. The blanking assembly 28 includes upper and lower furnace tube expansion joints.

[0231] The upper furnace tube also includes a third superheated steam inlet 2404 located at the top of the upper furnace tube feed section and a fourth superheated steam inlet 2405 located at the top of the middle section of the upper furnace tube; the lower furnace tube also includes a fifth superheated steam inlet 2503 located at the top of the lower furnace tube feed section and a sixth superheated steam inlet 2504 located at the top of the middle section of the lower furnace tube.

[0232] The second supporting frame includes an upper and lower rectangular frame having the same structure and being parallel to each other. The upper rectangular frame is used to fix the upper furnace tube, and the lower rectangular frame is used to fix the lower furnace tube.

[0233] The multi-stage superheated steam cracking furnace further includes a heat-insulating layer wrapped around the outer periphery of the frame.

[0234] Example 3

[0235] This embodiment provides an electronic waste continuous superheated steam cracking system, which uses the superheated steam cracking furnace provided in Example 1.

[0236] An electronic waste cracking processing system includes a raw material processing unit, a continuous superheated steam thermal cracking unit connected to the raw material processing unit through a feeding unit, and an oil and gas processing unit and a discharge sorting unit respectively connected to the oil and gas output end and solid output end of the superheated steam thermal cracking unit.

[0237] The continuous superheated steam cracking unit includes a superheated steam cracking furnace B1 or a multi-stage superheated steam cracking furnace, a superheated steam distribution system and a gas heating system; the superheated steam distribution system is located in the thermal insulation layer of the superheated steam cracking furnace, and includes a first superheated steam preheating main pipe and a second superheated steam preheating main pipe surrounding the outer wall of the superheated steam cracking furnace; one end of the first steam preheating main pipe is connected to an external water supply or steam supply main pipe, and the other end is connected to the first steam inlet or the third steam inlet, and the fifth steam inlet through a pipeline; one end of the second steam preheating main pipe is connected to the external water supply or steam supply main pipe, and the other end is connected to the second steam inlet or the fourth steam inlet, and the sixth steam inlet through a pipeline; the gas heating system includes a burner connected to the external gas main pipe.

[0238] The raw material processing unit includes a raw material feeding belt A1, a parts storage bin A2, a crushing device A3, a crushed material conveying belt A4, a crushed material buffer bin A5 and a crushed material spiral conveying belt A6 which are connected in sequence.

[0239] The feeding system comprises an upper hopper, a feeding upper sealing valve, a feeding intermediate tank, a feeding lower sealing valve and a feeding buffer tank which are connected in sequence.

[0240] The oil and gas processing unit includes an oil and gas outlet pipe, an oil and gas catalytic reactor C1, an oil and gas processor C2, an oil-water separator C3 and an oil purifier which are connected in sequence; the catalyst of the oil and gas catalytic reactor is made of ceramic nickel iron.

[0241] The discharging and sorting unit includes a water-cooling conveying system and a sorting system which are connected in sequence.

[0242] The water-cooled conveying system is connected to the solid output end of the continuous superheated steam cracking unit, and includes a discharge pipe, a water-cooled tank, a gate valve, a discharge upper sealing valve, a discharge intermediate tank, a discharge lower sealing valve and a water-cooled conveyor D1 connected in sequence. The output end of the water-cooled conveyor is connected to the sorting system.

[0243] The sorting system includes a solid sorting and storage tank D2 and a solid conveyor belt D3 connected to a water-cooled conveying system; the water-cooled conveying system sends the solid reaction product into the reaction solid sorting and storage tank for sorting, and then separates the metal from glass fiber, carbon black, etc. through the solid conveyor belt; the separated glass fiber, carbon black, etc. are sent to an external glass fiber and carbon black collection device for storage; the separated metal is briquetteed by a briquetting machine and then subsequently processed.

[0244] The e-waste pyrolysis system also includes a metal smelting unit, an exhaust gas purification unit F1, and a wastewater treatment unit G1. The metal smelting unit includes a metal smelting furnace, where the briquetted metal enters the furnace for smelting. Exhaust gas generated during the smelting process enters the exhaust gas purification unit for purification. The metal smelting furnace is a jet-type furnace, which can generate large amounts of fuel oil and gas using the system, achieving resource recycling.

[0245] The electronic waste cracking treatment system further comprises a circulating cooling unit, which provides circulating cooling water for the water cooling tank, dynamic equipment cooling and sealing of the electronic waste cracking treatment system.

[0246] The electronic waste cracking and processing system also includes a control system.

[0247] The electronic waste cracking treatment system also includes: a temperature measurement system installed at key nodes of the reactor, including at least three temperature measurement points: the furnace tube inlet, the cracking section, and the oil and gas outlet; a pressure measurement system distributed in the gas and solid phase pipelines, including high-temperature resistant pressure sensors; the measurement system and control system adjust the cracking process parameters in real time.

[0248] The operation process of the electronic waste cracking treatment system:

[0249] Raw materials are loaded via a closed conveyor belt. After passing through a magnetic separator and manual sorting stations to separate the transformer, coil, and radiator, the sorted material is conveyed to a component storage bin. The remaining material enters a fully enclosed crusher for crushing, where metal separation, dust collection, and material classification are achieved, ensuring the crushed particle size is controlled within a specified range. The crushed material is then transported to a surge bin for temporary storage via a closed conveying system, and then fed into the feed system via a spiral conveyor belt. During feeding, the lower sealing valve is closed, and the material enters the feed intermediate tank through the upper sealing valve. The upper sealing valve is then closed, nitrogen is introduced to displace the air, and the lower sealing valve is opened to allow the material to enter the feed surge tank for final delivery to the cracking furnace.

[0250] During operation, the fuel gas system heats the furnace tubes with external fuel gas from burners. Simultaneously, waste heat from the flue gas in the furnace tubes heats the superheated steam system, bringing the superheated steam in the preheating main to the desired temperature. The cracking products are divided into gaseous cracked gas and solid residue. The gaseous cracked gas enters the subsequent oil and gas processing unit, while the solid residue passes through the discharge pipe into a water-cooled tank for cooling. It then passes through a gate valve and sealing valve system into the discharge intermediate tank. After nitrogen is filled to displace the air, the material enters a water-cooled conveyor. The water-cooled conveyor system utilizes a multi-stage sealing and cooling design to ensure the safe discharge of high-temperature materials without gas leakage.

[0251] The cooled solid residue is conveyed via a conveyor belt to a sorting system, where metal is separated from non-metallic materials such as glass fiber and carbon black in a reaction solids sorting and storage tank. The separated glass fiber and carbon black are then stored in an external collection device, while the metal is briquetted in a briquetting machine and transported to the metal smelting unit for smelting. Exhaust gas generated during the smelting process is treated in an exhaust gas purification unit, while the fuel and gas produced by the system are recycled. Furthermore, a circulating cooling unit provides circulating cooling water to the water-cooled tanks, motor cooling, and sealing systems, ensuring stable system operation.

[0252] Application Example 1

[0253] This application example is based on the electronic waste cracking treatment system of Example 3 for electronic waste treatment.

[0254] The electronic waste to be processed is PCB substrate, and its raw material composition is shown in Table 1.

[0255] The annual operating time is 300 days, the production load factor is 0.95, and the hourly processing capacity is 8.769t / h.

[0256] The specific processing process is as follows:

[0257] Raw materials are loaded via a closed conveyor belt. After passing through a magnetic separator and manual sorting stations to separate the transformer, coil, and radiator, the sorted material is conveyed to a component storage bin. The remaining material enters a fully enclosed crusher for crushing, where metal separation, dust collection, and material classification are achieved, ensuring the crushed particle size is controlled within a specified range. The crushed material is then transported to a surge bin for temporary storage via a closed conveying system, and then fed into the feed system via a spiral conveyor belt. During feeding, the lower sealing valve is closed, and the material enters the feed intermediate tank through the upper sealing valve. The upper sealing valve is then closed, nitrogen is introduced to displace the air, and the lower sealing valve is opened to allow the material to enter the feed surge tank for final delivery to the cracking furnace.

[0258] During operation, the fuel gas system heats the furnace tubes by burning external fuel gas through burners. Simultaneously, the waste heat from the flue gas in the furnace tubes heats the superheated steam system, bringing the superheated steam in the preheating main to the desired temperature. The cracking products are divided into gaseous cracked gas and solid residue. The gaseous cracked gas enters the subsequent oil and gas processing unit, while the solid residue enters a water-cooled tank for cooling through a discharge pipe. It then passes through a gate valve and sealing valve system into an intermediate discharge tank. After nitrogen is filled to displace the air, the material enters a water-cooled conveyor.

[0259] The cooled solid residue is conveyed via a conveyor belt to a sorting system, where metal is separated from non-metallic materials such as glass fiber and carbon black in a reaction solids sorting and storage tank. The separated glass fiber and carbon black are then stored in an external collection device, while the metal is briquetted in a briquetting machine and transported to the metal smelting unit for smelting. Exhaust gas generated during the smelting process is treated in an exhaust gas purification unit, while the fuel and gas produced by the system are recycled. Furthermore, a circulating cooling unit provides circulating cooling water for the water-cooled tanks, motor cooling, and sealing systems.

[0260] Under continuous production conditions of 300 days per year and a load factor of 0.95, a 10m-long cracking furnace tube has accumulated more than 6,800 hours of operation at 900°C. The radial deformation of the furnace tube is always controlled at <0.3mm / m, and the axial thermal deformation is completely absorbed by the compensation system. After 100 thermal cycles, the furnace tube welds were found to have no cracking.

[0261] The inner and outer double-tube drive shaft system absorbs thermal deformation through an axial-radial composite compensation mechanism. The rib-groove matching structure of the guide support ring allows free axial displacement while precisely constraining circumferential rotation. The matching bearing sealing system adopts a multi-stage dynamic sealing design to maintain stable sealing performance under high-temperature alternating working conditions.

[0262] The system input / output situation is shown in Table 2.

[0263] Table 1 PCB substrate raw material composition (Cu 27.9%)

[0264] Serial number Circuit board components Content (% / kg) 60,000 tons / a one PCB substrate 66.590％ 39954.00 1 fiberglass 34.960％ 20975.85 2 Resin (containing bromide) 12.652％ 7591.26 3 Epoxy resin (bromide-free) 18.978％ 11386.89 two ink 4.400％ 2640.00 1 Epoxy resin and acrylic copolymer 42.000％ 25200.00 2 barium sulfate 32.000％ 19200.00 3 Photoinitiator 10.000％ 6000.00 4 Solvents and additives 20.000％ 12000.00 three Metal composition 29.011％ 17406.60 1 Copper 27.900％ 16740.00 2 tin 0.500％ 300.00 3 gold 0.001％ 0.60 4 nickel 0.100％ 60.00 5 zinc 0.500％ 300.00 6 lead 0.010％ 6.00 Four total 100.001％ 60000.60

[0265] Table 2 Input / output of 60,000 tons of PCB boards processed annually

[0266]

[0267]

[0268] The operational tests of this application example show that the electronic waste cracking and processing system of the present invention achieves: industrial-scale operation with an annual processing capacity of 60,000 tons of electronic waste within an adjustable feed rate range of 0 to 8.769 t / h, a 100% metal component recovery rate, high energy and resource utilization rates, a loss rate of only 0.28%, and no dioxins in the exhaust gas.

[0269] In summary, the present invention achieves comprehensive thermal deformation compensation and stable operation of a superheated steam cracking furnace under high-temperature conditions through a multi-system collaborative design. The furnace tubes utilize a composite structure of sliding support units and elastic suspension units. Through the ingenious combination of rigid guide rails and flexible suspension, they simultaneously address the requirements of axial sliding compensation and radial elastic support. The dual-tube drive shafts, with differentiated temperature control for the inner and outer tubes and a composite end connection mechanism, ensure torque transmission while adaptively compensating for thermal deformation. The sealing system integrates the advantages of rigid fixed ends and flexible sliding ends, and, in conjunction with directional cooling, provides dynamic sealing protection. Through the coordinated mechanism of "fixed constraint-sliding compensation-elastic buffering," these subsystems fully relieve axial and radial thermal stresses in large-sized furnace tubes under high temperatures. The transmission system maintains stable transmission under temperature differentials, and the sealing assembly adapts to large sliding displacements. This achieves multi-degree-of-freedom compensation for high-temperature equipment, effectively overcoming the technical bottlenecks of deformation, cracking, and seal failure that plague conventional cracking furnaces during long-term, high-temperature operation.

[0270] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with this technical field within the technical scope disclosed by the present invention should be covered by the scope of protection of the present invention.

Claims

1. A superheated steam cracking furnace, characterized in that: The furnace tube is connected to the support frame through a support system; the support system includes a sliding support unit and a sliding suspension unit; The furnace tube includes a transmission shaft, a furnace shell sleeved on the outer periphery of the transmission shaft, and a first end cover and a second end cover installed at both ends of the furnace shell; One end of the furnace tube is fixedly connected to the support frame through a first end cover and a fixing assembly, the other end is slidably connected to the support frame through a sliding support unit, and the middle part of the furnace tube is connected to the frame through a sliding hanging unit.

2. The cracking furnace according to claim 1, characterized in that The transmission shaft includes an inner tube and an outer tube.

3. The cracking furnace according to claim 2, characterized in that More than one stirring assembly is installed along the axial direction on the outer periphery of the outer tube.

4. The cracking furnace according to claim 3, characterized in that Each stirring assembly includes two 180° split clamping sleeves, which are symmetrically fastened to form a complete annular structure, and are radially fixed by bolts through connecting ears extending from both ends of the clamping sleeves; the clamping sleeves include a first clamping sleeve and a second clamping sleeve.

5. The cracking furnace according to claim 4, characterized in that Two stirring pieces are arranged circumferentially symmetrically on each of the first clamping sleeves. A single stirring piece includes a main body and a shovel head, and the central axes of the two stirring pieces are fixed at an angle of 120°. The center lines of the main bodies of the two stirring pieces on the same first clamping sleeve are distributed at a circumferential angle of 90°, and the center line of the main body of each stirring piece maintains a phase angle of 30° with the center line of the adjacent connecting ear.

6. The cracking furnace according to claim 4, characterized in that Each of the second clamping sleeves is provided with a stirring piece, and the center line of the main body of the stirring piece on the second clamping sleeve forms a phase angle of 90 degrees with the center line of the connecting ear.

7. The cracking furnace according to claim 3, characterized in that The stirring pieces of adjacent stirring components are arranged with a phase difference of 1° to 45°.

8. The cracking furnace according to claim 1, characterized in that The furnace shell is provided with a heating assembly, including either an electromagnetic induction system or a resistance heating system.

9. The cracking furnace according to claim 1, characterized in that The furnace tube also includes a first top feed port, a first bottom drop port, a first superheated steam inlet, a second superheated steam inlet and a first oil and gas outlet. The first top feed port is located at the top of the connection end between the furnace tube and the sliding support unit, and the first bottom drop port and the first oil and gas outlet are respectively located at the bottom and top of the fixed connection end between the furnace tube and the frame; the first superheated steam inlet is arranged at the top of the furnace tube feed section; the second superheated steam inlet is arranged at the top of the middle section of the furnace tube.

10. An electronic waste cracking treatment system, characterized in that: It comprises the superheated steam cracking furnace according to any one of claims 1 to 9.

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