A dehydrogenation reactor internal manufacturing precision control process

Abstract

The application belongs to the field of dehydrogenation reactor manufacturing process, and particularly discloses a dehydrogenation reactor inner part manufacturing precision control process, which is characterized by the following aspects: the development and improvement of the cylinder forming size control, the coaxiality, flatness and bolt hole size control of the inner net base and the bottom head, the large inner and outer net horizontal sleeving auxiliary device and the installation method, so as to ensure the flatness, roundness and bolt hole positioning size precision of the supporting ring; the process is particularly suitable for the manufacturing and inner part installation of large and super-large dehydrogenation reactors, and can successfully install the outer net with a length of 27 m and a weight of 93 tons and the inner net with a weight of 72 tons in place under the 6 mm movable gap, so as to finally realize the high precision requirement that the coaxiality of the product technical requirement inner part installation distribution cone, inner net and outer net is within ±2.5 mm; the process has good practicability and can produce good industry benefits.

Description

Technical Field

[0001] This invention belongs to the field of dehydrogenation reactor manufacturing technology, and specifically discloses a process for controlling the manufacturing precision of dehydrogenation reactor internals. Background Technology

[0002] The dehydrogenation reactor is a core piece of equipment in chemical plants. The equipment consists of a cylinder, an inner mesh, an outer mesh, and a distribution cone.

[0003] Dehydrogenation reactors operate under high temperature and negative pressure conditions. The precision of internal component installation directly affects the catalyst utilization rate of axial-radial flow reactors. High-quality equipment helps reduce side reactions, lower catalyst bed pressure drop, and facilitates negative pressure operation. The high-precision internal component installation requirements also increase the manufacturing precision requirements of the equipment body. How to successfully install a 27m long, 93-ton outer mesh and a 72-ton inner mesh within a 6mm clearance is a challenge. Previous internal component installation methods for small dehydrogenation reactors are no longer applicable to the installation of large-diameter, heavy-tonnage internal components. Therefore, the development of high-precision manufacturing technology for large dehydrogenation reactor equipment faces a series of core technical challenges. CN105798567B discloses the installation method of inner and outer distribution cylinders in a dehydrogenation reactor, in which...

[0004] The outer protective plate, outer trolley, and outer guide rail are spot-welded to the cylinder as tracks. Because the gap between the outer net and the cylinder is very small, the removal of the outer guide rail requires personnel to climb into the outer net and the equipment to grind the weld seams before removal, which is too difficult. In the above invention, the outer trolley wheels have grooves to cooperate with the angle steel of the outer guide rail. Because the main trolley is used to lift the equipment during installation, the outer net inevitably swings left and right, which can easily cause the outer trolley to derail from the outer guide rail. After the outer net is installed in the equipment, the outer protective plate and outer trolley are always pressed down by the outer net. It is too difficult to remove the outer protective plate and outer trolley from the cylinder by simply relying on wooden blocks to support them. CN215885203 discloses a horizontal installation track device for large-diameter, heavy-duty internal components. The inner mesh wheels are connected to the channel steel track. The inner mesh wheels are single-sided protruding channel steel structures. In the actual installation process of the inner mesh, the inner mesh will inevitably swing left and right, which can easily cause the inner mesh wheels to derail from the channel steel track. Moreover, the channel steel structure has too low strength and cannot meet the load-bearing requirements for the movement of the internal components, making it easy to deform. Summary of the Invention

[0005] To address the aforementioned issues, this invention discloses a manufacturing precision control process for internal components of a dehydrogenation reactor. Specifically, it discloses a process for controlling the coaxiality and flatness of the internal component base and the equipment in a dehydrogenation reactor, welding anti-deformation measures, and an internal component installation method.

[0006] The present invention adopts the following technical solution:

[0007] A process for controlling the manufacturing precision of dehydrogenation reactor internals includes the following steps:

[0008] Step 1. When forming the cylinder, the longitudinal circumferential seam bevel is prepared by machining. The unfolded length of the cylinder varies depending on the thickness of the steel plate and the amount of weld shrinkage is reserved. A shrinkage allowance of 8-12% of the cylinder wall thickness and not less than 4mm is reserved.

[0009] Step 2. The inner mesh base consists of a connecting flange and a supporting cone. The thickness of the connecting flange is reserved with 8-12mm for subsequent machining. The inner and outer diameters are each reserved with 8-12mm for subsequent machining. When rolling the supporting cone, the wall thickness is increased by 3-5mm. After forming, the outer diameter of the cone's small opening needs to be machined vertically to ensure roundness. After the connecting flange is welded in sections, the bolt holes and the flatness of the upper surface are not machined for the time being. The inner diameter is machined according to the matching outer diameter of the cone's small opening. The connecting flange and the supporting cone are assembled and welded. The inner hole of the connecting flange is opened with a double-sided bevel. Argon arc welding is used for the root pass, and φ3.2 electrode arc welding is used for welding. Symmetrical welding is adopted for both sides to control deformation to the maximum extent. After welding, the outer diameter of the connecting flange is machined to be 4-6mm larger than the drawing requirements.

[0010] Step 3. When forming the bottom end cap, the ellipticity of the bottom end cap at the diameter position of the outer and inner mesh bases and the end cap port must be strictly controlled. When processing the end cap bevel, one port is used as a reference to draw concentric circles of the inner and outer mesh bases at the assembly position to ensure subsequent coaxiality requirements.

[0011] Step 4. Assemble the inner mesh base and the bottom end cap. When assembling, ensure the coaxiality requirement by installing the above-marked positions. Before welding the support cone and the bottom end cap, ensure that the assembly gap is uniform and that multiple people weld symmetrically at the same time to prevent welding deformation.

[0012] Step 5. Using the bottom end cap port as a reference, machine the upper surface and outer circle dimensions of the connecting flange to ensure the coaxiality requirement between the inner mesh base and the dehydrogenation reactor. Then, using the outer circle of the bottom end cap as a reference, draw the concentric circle dimensions of the bolt holes to ensure the coaxiality requirement between the inner mesh base and the dehydrogenation reactor, thereby ensuring the coaxiality requirement between the inner mesh and the dehydrogenation reactor.

[0013] Step 6. After the bottom end cap and the cylinder are welded together, assemble the outer mesh. Place the outer mesh trolley on the outer wall of the front end of the outer mesh, and use ground anchors and fixed pulleys as steel wire ropes to change the direction of traction. Pass the steel wire rope through the pipe opening of the lower end cap, and use an overhead crane to provide the power for forward movement. The tail of the outer mesh is hoisted by a steel wire rope and moved laterally by the overhead crane. The two cranes work simultaneously to assemble the outer mesh to the inner wall of the bottom end cap. When there is a deviation between the outer mesh and the internal marking reference of the bottom end cap, use a chain hoist to fine-tune the front end of the outer mesh to ensure the coaxiality requirement between the outer mesh and the dehydrogenation reactor.

[0014] Step 7. Lay rubber pads inside the outer mesh to protect it from impacts or pressure damage. Use two I-beam rails and bolts and nuts for installation. The I-beam rails can be spliced ​​in multiple sections for easy manual handling inside the dehydrogenation reactor. Install an inner mesh trolley on the inner mesh rails. The trolley's wheel hubs protrude on both sides to ensure that the grooves of the wheel hubs completely engage with the upper surface of the I-beam rails, preventing the wheels from derailing when the inner mesh moves. Above the inner mesh trolley is an arc plate, the height of which is coaxial with the inner mesh installation position. When the bottom flange of the inner mesh and the bolt holes of the inner mesh base flange are fully aligned, and the outer circles of the two flanges are flush, the coaxiality requirement between the inner mesh and the dehydrogenation reactor is guaranteed.

[0015] Furthermore, regarding the above-mentioned precision control process for manufacturing internals of a dehydrogenation reactor, the welding process parameters in step 2 or 4 are shown in the following table:

[0016]

[0017] Furthermore, in the above-mentioned process for controlling the manufacturing precision of internal components of a dehydrogenation reactor, in step 1, a shrinkage allowance of 10% of the cylinder wall thickness and not less than 4 mm is reserved.

[0018] Furthermore, in the above-mentioned process for controlling the manufacturing precision of internal components of a dehydrogenation reactor, in step 2, a 10mm machining allowance is reserved for the thickness of the connecting flange, a 10mm machining allowance is reserved for both the inner and outer diameters, and the wall thickness is increased by 4mm when the support cone is rolled.

[0019] Furthermore, in the above-mentioned process for controlling the manufacturing precision of internal components of a dehydrogenation reactor, in step 2, the outer diameter of the welded connecting flange is 5mm larger than the drawing requirement.

[0020] Furthermore, in the aforementioned process for controlling the manufacturing precision of internal components of a dehydrogenation reactor, the inner track includes a base plate, track bolts, track nuts, tie rods, inner clamping plates, an I-beam steel track, an outer clamping plate, a support plate, and vertical ribs. The base plate is located at the bottom of the track and is fixed to the underside of the I-beam steel track by track bolts and track nuts. Tie rods and inner clamping plates on both sides of the tie rods are also provided above the base plate to fix the inner side of the I-beam steel track. An outer clamping plate, a support plate, and track vertical ribs are also provided on the outer side of the I-beam steel track to fix the outer side of the I-beam steel track.

[0021] Furthermore, in the aforementioned process for controlling the manufacturing precision of internal components of a dehydrogenation reactor, the inner trolley includes wheels, trolley bolts, trolley uprights, a flat plate, trolley nuts, an arc plate, and supports. The wheels are located at the bottom of the inner trolley and are rolled and fixed to the uprights on both sides of the wheels by a combination of trolley bolts and trolley nuts. The flat plate is located above the two wheels. Several supports are also vertically arranged above the flat plate, and the top of the supports is provided with a concave arc plate.

[0022] Furthermore, in the aforementioned process for controlling the manufacturing precision of internal components of a dehydrogenation reactor, the surface of the wheel is configured with a groove structure, the groove depth is 40mm, and the wall thickness on both sides of the groove is 20mm; it fits into the I-beam steel track.

[0023] Furthermore, the present invention discloses a dehydrogenation reactor, which is manufactured and assembled using the above-described process.

[0024] Furthermore, in the aforementioned dehydrogenation reactor, the coaxiality of the distribution cone, inner mesh, outer mesh, and dehydrogenation reactor is controlled within ±2.5 mm.

[0025] Furthermore, the aforementioned dehydrogenation reactor is a large-scale dehydrogenation reactor.

[0026] Compared with existing technologies, this invention has the following outstanding innovations and beneficial effects:

[0027] 1. Innovation points:

[0028] (1) When forming the cylinder, the unfolded length of the cylinder varies depending on the thickness of the steel plate and the amount of weld shrinkage reserved. The shrinkage allowance is reserved at 8-12% of the cylinder wall thickness and not less than 4mm.

[0029] (2) Leave 8-12mm of machining allowance for the thickness of the connecting flange, and leave 8-12mm of machining allowance for the inner and outer diameters. When rolling the support cone, increase the wall thickness by 3-5mm. After forming, the outer diameter of the cone's small opening needs to be machined on a vertical lathe to ensure roundness. After the connecting flange is welded in sections, the bolt holes and the flatness of the upper surface are not machined for the time being. The inner diameter is machined according to the matching outer diameter of the cone's small opening. The connecting flange and the cone are assembled and welded. After welding, the outer diameter of the connecting flange is 4-6mm larger than the drawing requirements.

[0030] (3) When processing the bevel of the end cap, use one end as a reference to draw concentric circles at the assembly positions of the inner mesh base and the outer mesh to ensure the coaxiality requirements in the future.

[0031] (4) Using the bottom end cap port as a reference, process the upper surface and outer circle dimensions of the connecting flange to ensure the coaxiality requirements of the inner mesh base and the equipment. Then, using the outer circle of the bottom end cap as a reference, draw the concentric circle dimensions of the bolt holes to ensure the coaxiality requirements of the inner mesh base and the equipment, thereby ensuring the coaxiality requirements of the inner mesh and the equipment.

[0032] (5) Development of installation schemes and equipment for external and internal networks: Because the internal components of large dehydrogenation reactors are much heavier than those of previous small equipment, ordinary fixed pulleys suspended in mid-air cannot withstand the force of internal component movement. Therefore, a structure combining ground anchors and support fixed pulleys was developed to change the direction of the crane traction force, which is suitable for improving the installation scheme of internal components of dehydrogenation reactors.

[0033] (6) The inner net track and the inner net trolley are coordinated. The inner net track is assembled with I-beam steel rails, rail bolts and rail nuts. Because the inner net is heavy, and the inner net is subject to dynamic loads of swaying back and forth and left and right during the assembly process, the strength requirements of the inner net track are very high. Therefore, the inner net track is very heavy. This equipment is designed with a detachable I-beam steel rail, rail bolt and rail nut assembly structure, which is easy to assemble. In order to meet the requirements of strength and lightweight design, the 204 tie rod structure design and the inner and outer clamping plates are the innovation points.

[0034] (7) The most important innovation in the installation of the internal components is the perfect fit between the inner net trolley wheel hub and the I-beam steel rail. The wheel hub has a groove structure with a groove depth of 40mm and a wall thickness of 20mm on both sides of the groove. This ensures that the inner net trolley will not derail due to the inevitable back-and-forth and left-and-right swaying that occurs when the inner net moves forward using the overhead crane.

[0035] 2. Beneficial effects:

[0036] (1) The longitudinal seam of the cylinder is reserved for shrinkage, and the ellipticity control can provide a good foundation for the installation of the outer net. (2) The bottom end cap serves as the installation foundation for the inner net base and the outer net. The manufacturing accuracy of the bottom end cap directly affects the installation accuracy of the inner net base and the outer net.

[0037] (3) Deformation control after welding of the inner mesh base ring plate and cone assembly.

[0038] (4) The coaxiality of the flange and the end cap after the inner mesh base and the bottom end cap are welded together, the flatness of the flange sealing surface and the manufacturing accuracy of the bolt holes directly affect the assembly accuracy of the coaxiality between the inner mesh and the equipment.

[0039] (5) The design of the auxiliary device for horizontal installation of the external network can smoothly complete the horizontal installation of the external network.

[0040] (6) The design of the horizontal installation track of the inner net can meet the smooth installation of large-diameter, large-tonnage horizontal inner nets. Attached Figure Description

[0041] Figure 1 Dehydrogenation reactor structural diagram;

[0042] Figure 2 External network installation diagram;

[0043] Figure 3 Intranet installation diagram;

[0044] Figure 4 Schematic diagram of the internal network track structure;

[0045] Figure 5 Detailed diagram of the internal network track;

[0046] Figure 6 Schematic diagram of the intranet vehicle structure;

[0047] Figure 7 Photos of the actual device installed on the external network.

[0048] Among them: 1 is the outer net trolley, 2 is the inner net track, 3 is the inner net trolley, 4 is the bottom end cap, 5 is the cylinder, 6 is the outer net, 7 is the inner net, 8 is the distribution cone, 9 is the connecting flange, 10 is the supporting cone, 11 is the overhead crane, 12 is the wire rope, 13 is the ground anchor, 14 is the fixed pulley, 15 is the connecting pipe, 16 is the traction lug, 17 is the lifting chain hoist, 18 is the lifting lug, and 19 is the inner net base;

[0049] 201 is the base plate, 202 is the rail bolt, 203 is the rail nut, 204 is the tie rod, 205 is the inner clamping plate, 206 is the I-beam rail, 207 is the outer clamping plate, 208 is the support plate, and 209 is the rail vertical reinforcement.

[0050] 301 is the wheel, 302 is the trolley bolt, 303 is the trolley upright, 304 is the flat plate, 305 is the trolley nut, 306 is the arc plate, and 307 is the support. Detailed Implementation

[0051] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0052] Example

[0053] like Figure 1-6 The process for controlling the manufacturing precision of internal components of a dehydrogenation reactor, as shown, includes the following steps:

[0054] Step 1. When forming the cylinder 5, the longitudinal circumferential seam bevel is prepared by machining. The unfolded length of the cylinder 5 varies depending on the thickness of the steel plate and the amount of weld shrinkage reserved. A shrinkage allowance of 10% of the wall thickness of the cylinder 5 and not less than 4mm is reserved.

[0055] Step 2. The inner mesh base 19 consists of a connecting flange 9 and a supporting cone 10. The thickness of the connecting flange 9 is reserved with a 10mm allowance for subsequent machining, and the inner and outer diameters are each reserved with a 10mm allowance for subsequent machining. When the supporting cone 10 is rolled, the wall thickness is increased by 4mm. After forming, the outer diameter of the cone's small opening needs to be machined vertically to ensure roundness. After the connecting flange 9 is welded in sections, the bolt holes and the flatness of the upper surface are not machined for the time being. The inner diameter is machined according to the matching outer diameter of the cone's small opening. The connecting flange 9 and the supporting cone 10 are assembled and welded. The inner hole of the connecting flange 9 is opened with a double-sided bevel. Argon arc welding is used for the root pass, and φ3.2 electrode arc welding is used for welding. Symmetrical welding is adopted for both sides to control deformation to the maximum extent. After welding, the outer diameter of the connecting flange 9 is 5mm larger than the drawing requirements.

[0056] Step 3. When forming the bottom head 4, the ellipticity of the bottom head at the diameter position of the outer mesh 6 and the inner mesh base 19 and the end of the head should be strictly controlled. When processing the bottom head bevel, one end is used as a reference to draw concentric circles of the inner mesh base and the outer mesh base at the assembly position to ensure the subsequent coaxiality requirements.

[0057] Step 4. Assemble the inner mesh base and the bottom end cap 4. When assembling, ensure the coaxiality requirement by installing the above-marked positions. Before welding the support cone 10 and the bottom end cap 4, ensure that the assembly gap is uniform and that multiple people weld symmetrically at the same time to prevent welding deformation.

[0058] Step 5. Using the bottom end cap port as a reference, machine the upper surface and outer circle dimensions of the connecting flange 9 to ensure the coaxiality requirement between the inner mesh base and the dehydrogenation reactor. Then, using the outer circle of the bottom end cap as a reference, draw the concentric circle dimensions of the bolt holes to ensure the coaxiality requirement between the inner mesh base and the dehydrogenation reactor, thereby ensuring the coaxiality requirement between the inner mesh 7 and the dehydrogenation reactor.

[0059] Step 6. After the bottom end cap 4 and the cylinder 5 are welded together, assemble the outer mesh 6. Place the outer mesh trolley 1 on the outer wall of the front end of the outer mesh, and use the ground anchor 13 and fixed pulley 14 as steel wire rope 12 to change the direction of the traction force. Pass the steel wire rope through the pipe opening of the bottom end cap 4, and use the overhead crane 11 to provide the power for forward movement. The tail of the outer mesh 6 is hoisted by the steel wire rope 12 and moved laterally by the overhead crane 11. The two cranes 11 work simultaneously to assemble the outer mesh 6 to the inner wall of the bottom end cap 4. When there is a deviation between the outer mesh 6 and the internal marking reference of the bottom end cap 4, use a chain hoist to fine-tune the front end of the outer mesh 6 to ensure the coaxiality requirement between the outer mesh 6 and the dehydrogenation reactor.

[0060] Step 7. Lay rubber pads inside the outer net 6 to protect it from impacts or pressure damage. Use two I-beam rails 206, rail bolts 202, and rail nuts 203. The I-beam rails 206 can be spliced ​​in multiple sections for easy manual handling inside the dehydrogenation reactor. Install the inner net trolley 3 on the inner net rail 2. The trolley's wheel hubs protrude on both sides to ensure that the grooves of the wheel hubs completely engage with the upper surface of the I-beam rails 206, preventing the wheels from derailing when the inner net 7 moves. Above the inner net trolley 3 is an arc plate 306, the height of which is coaxial with the inner net installation position. When the bottom flange of the inner net 7 is fully aligned with the bolt holes of the inner net base flange, and the outer circles of the two flanges are flush, the coaxiality requirement between the inner net 7 and the dehydrogenation reactor is guaranteed.

[0061] The welding process parameters in steps 2 and 4 are shown in the table below:

[0062]

[0063] Preferably, the inner track includes a base plate 201, track bolts 202, track nuts 203, tie rods 204, inner clamping plates 205, I-beam steel rails 206, outer clamping plates 207, support plates 208, and vertical ribs 209. The base plate 201 is located at the bottom of the track and is fixed to the underside of the I-beam steel rails 206 by track bolts 202 and track nuts 203. Tie rods 204 and inner clamping plates 205 on both sides of the tie rods 204 are also provided above the base plate 201 to fix the inner side of the I-beam steel rails 206. The outer side of the I-beam steel rails 206 is also provided with outer clamping plates 207, support plates 208, and track vertical ribs 209 to fix the outer side of the I-beam steel rails 206.

[0064] Preferably, the inner net trolley 3 includes wheels 301, trolley bolts 302, trolley uprights 303, a flat plate 304, trolley nuts 305, an arc plate 306, and supports 307. The wheels 301 are located at the bottom of the inner net trolley 3 and are rolled and fixed to the uprights 303 on both sides of the wheels 301 by a combination of trolley bolts 302 and trolley nuts 305. The flat plate 304 is located above the two wheels 301. Several supports 307 are also vertically arranged above the flat plate 304, and the top of the supports 307 is provided with a concave arc plate 306.

[0065] Results: The outer net, which is 27m long and weighs 93 tons, and the inner net, which weighs 72 tons, can be successfully installed in place with a 6mm gap. Furthermore, the coaxiality of the distribution cone, inner net, outer net, and dehydrogenation reactor in the above-mentioned dehydrogenation reactor is controlled within ±2.5mm.

[0066] As can be seen from the above embodiments, this invention discloses a precision control process for the manufacturing of internal components of a dehydrogenation reactor. Through control of the cylinder forming dimensions, control of the coaxiality, flatness, and bolt hole dimensions of the inner mesh base and bottom end cap, and the development and improvement of auxiliary devices and installation methods for the horizontal assembly of large inner and outer meshes, the accuracy of the flatness, roundness, and bolt hole positioning dimensions of the support ring is ensured. Ultimately, the high precision requirement of ±2.5mm coaxiality between the distribution cone, inner mesh, outer mesh, and equipment after internal component installation is achieved, as per the product's technical requirements. This process is particularly suitable for the manufacturing and installation of internal components for large and ultra-large dehydrogenation reactors. It can smoothly install a 27m long, 93-ton outer mesh and a 72-ton inner mesh with a 6mm clearance, demonstrating good practicality and generating significant industry benefits.

[0067] The above are merely a few preferred embodiments of the present invention, described in a relatively specific and detailed manner, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention.

Claims

1. A manufacturing precision control process for internal components of a dehydrogenation reactor, characterized in that, Includes the following steps: Step 1. When forming the cylinder (5), the longitudinal circumferential seam bevel is prepared by machining. The unfolded length of the cylinder (5) varies depending on the thickness of the steel plate and the amount of weld shrinkage is reserved. The shrinkage allowance is reserved at 8-12% of the wall thickness of the cylinder (5) and not less than 4mm. Step 2. The inner mesh base (19) consists of a connecting flange (9) and a supporting cone (10). The thickness of the connecting flange (9) is reserved with an 8-12mm allowance for subsequent processing. The inner and outer diameters are each reserved with an 8-12mm allowance for subsequent processing. When rolling the supporting cone (10), the wall thickness is increased by 3-5mm. After forming, the outer diameter of the small opening of the supporting cone (10) needs to be machined vertically to ensure roundness. The connecting flange (9) is made by splicing and welding in sections. In order to control the welding deformation of the joint, the joint bevel is double-sided. When welding the joint, the following measures are taken: Welding is performed alternately on both sides to control the heat input of welding and to control the change in flatness to the maximum extent. After the joint is welded, the bolt holes and the flatness of the upper surface are not processed for the time being. The inner diameter is processed according to the small outer diameter value of the matching support cone (10). The connecting flange (9) and the support cone (10) are assembled and welded. The inner hole of the connecting flange (9) is opened with a double bevel. Argon arc welding is used for the root pass. Small-sized electrode arc welding is used for welding. The welding is symmetrical to the front and back of the person to control the deformation to the maximum extent. After welding, the outer diameter of the connecting flange (9) is processed to be 4-6mm larger than the drawing requirements. The welding process parameters are as follows: When using welding material of grade ER309L and specification Ø2.0mm, the current is 120-150A, the voltage is 11-17V, the welding speed is ≥80mm / min, and the power supply is DC positive polarity. When using welding material of grade E309L and specification Ø3.2mm, the current is 90-110A, the voltage is 20-24V, the welding speed is ≥130mm / min, and the power supply is DC reverse polarity. When using welding material of grade E309L and specification Ø4.0mm, the current is 140-170A, the voltage is 22-26V, the welding speed is ≥150mm / min, and the power supply is DC reverse polarity. Step 3. When forming the bottom end cap (4), the ellipticity of the bottom end cap at the diameter position of the outer mesh (6) and the inner mesh base (19) and the end cap port must be strictly controlled. When processing the end cap bevel, the concentric circles of the inner mesh base (19) and the outer mesh (6) at the assembly position are drawn with the port as the reference to ensure the subsequent coaxiality requirements. Step 4. Assemble the inner mesh base (19) and the bottom end cap (4). Ensure coaxiality during assembly. Before welding the support cone (10) and the bottom end cap (4), ensure uniform assembly gaps and have multiple people weld symmetrically at the same time to prevent welding deformation. Step 5. Using the bottom end cap (4) port as a reference, process the upper surface and outer circle dimensions of the connecting flange (9) to ensure the coaxiality requirement between the inner mesh base (19) and the dehydrogenation reactor. Then, using the outer circle of the bottom end cap (4) as a reference, draw the concentric circle dimensions where the bolt holes are located to ensure the coaxiality requirement between the inner mesh base (19) and the dehydrogenation reactor, thereby ensuring the coaxiality requirement between the inner mesh (7) and the dehydrogenation reactor. Step 6. After the bottom end cap (4) and the cylinder (5) are welded together, the outer net (6) is assembled. The outer net trolley (1) is placed on the outer wall of the front end of the outer net. The ground anchor (13) and the fixed pulley (14) are used as components to change the direction of the traction force of the wire rope (12). The wire rope passes through the pipe opening of the bottom end cap (4) and the overhead crane (11) provides the power for forward movement. The tail of the outer net (6) is hoisted by the wire rope (12) and moved laterally by the overhead crane (11). The two overhead cranes (11) work simultaneously to assemble the outer net (6) to the inner wall of the bottom end cap (4). When there is a deviation between the outer net (6) and the internal marking reference of the bottom end cap (4), the front end of the outer net (6) is finely adjusted by the chain hoist to ensure the coaxiality requirement between the outer net (6) and the dehydrogenation reactor. Step 7. Lay rubber pads inside the outer net (6) to protect the inside of the outer net (6). Use two I-beam steel rails (206) and rail bolts (202) and rail nuts (203) to lay the inner net. The I-beam steel rails (206) can be spliced ​​in multiple sections to facilitate manual handling inside the dehydrogenation reactor. Set up an inner net trolley (3) on the inner net rail (2). The trolley's wheel hub is protruding on both sides to ensure that the groove of the trolley wheel hub completely locks the upper surface of the I-beam steel rail (206) to ensure that the trolley wheels do not derail from the rail when the inner net (7) moves. Above the inner net trolley (3) is an arc plate (306). The height of the arc plate (306) is coaxial with the inner net installation position. When the bottom flange of the inner net (7) is completely matched with the flange bolt hole of the inner net base (19) and the outer circles of the two flanges are flush, the coaxiality requirement between the inner net (7) and the dehydrogenation reactor is guaranteed.

2. The manufacturing precision control process for dehydrogenation reactor internals according to claim 1, characterized in that, In step 1, a shrinkage allowance of 10% of the wall thickness of the cylinder (5) and not less than 4mm is reserved.

3. The manufacturing precision control process for dehydrogenation reactor internals according to claim 1, characterized in that, In step 2, the thickness of the connecting flange (9) is reserved with a 10mm allowance for subsequent processing, and the inner and outer diameters are each reserved with a 10mm allowance for subsequent processing. When the support cone (10) is rolled, the wall thickness is increased by 4mm. After welding, the outer diameter of the connecting flange (9) is 5mm larger than the drawing requirement.

4. The manufacturing precision control process for dehydrogenation reactor internals according to claim 1, characterized in that, The inner track includes a base plate (201), track bolts (202), track nuts (203), tie rods (204), inner clamping plates (205), I-beam steel rails (206), outer clamping plates (207), support plates (208), and track uprights (209). The base plate (201) is located at the bottom of the track and is fixed to the bottom of the I-beam steel rails (206) by track bolts (202) and track nuts (203). Tie rods (204) and inner clamping plates (205) on both sides of the tie rods (204) are also provided above the base plate (201) to fix the inner side of the I-beam steel rails (206). Outer clamping plates (207), support plates (208), and track uprights (209) are also provided on the outer side of the I-beam steel rails (206) to fix the outer side of the I-beam steel rails (206).

5. The manufacturing precision control process for dehydrogenation reactor internals according to claim 1, characterized in that, The inner network trolley (3) includes wheels (301), trolley bolts (302), trolley uprights (303), a flat plate (304), trolley nuts (305), an arc plate (306), and supports (307). The wheels (301) are located at the bottom of the inner network trolley (3) and are rolled and fixed on the uprights (303) on both sides of the wheels (301) by a combination of trolley bolts (302) and trolley nuts (305). The flat plate (304) is located on the two wheels (301). Several supports (307) are also vertically arranged above the flat plate (304), and the top of the supports (307) is provided with a concave arc plate (306).

6. The manufacturing precision control process for dehydrogenation reactor internals according to claim 5, characterized in that, The surface of the wheel (301) is a groove structure with a groove depth of 40mm and a wall thickness of 20mm on both sides of the groove; the wheel (301) fits into the I-beam steel rail (206).

7. A dehydrogenation reactor, characterized in that, It is assembled using the precision control process described in any one of claims 1-6.

8. The dehydrogenation reactor according to claim 7, characterized in that, The coaxiality of the distribution cone (8), inner net (7), outer net (6) and dehydrogenation reactor is controlled within ±2.5 mm.

9. The dehydrogenation reactor according to claim 7, characterized in that, The dehydrogenation reactor is a large-scale dehydrogenation reactor.

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