Method for producing a large-sized ethylene oxide reactor grid support plate

Abstract

This invention provides a method for producing a large-size grating support plate for an ethylene oxide reactor, relating to the field of reactor equipment manufacturing technology. The method includes preparing single-piece grating strips, with controlled processing throughout the entire process, including material selection, dimensional tolerances, flatness during cutting, and grooving precision. Multiple single-piece grating strips are placed on an assembly platform and precisely positioned, locked, and welded together using positioning fixtures to form an integral grating support plate. The assembled grating support plate undergoes sequential single-layer precision self-inspection and multi-layer stacking alignment precision self-inspection. The inspected and qualified grating support plate is lifted under balanced stress using hoisting tools. Finally, the grating support plate is rigidly supported and fixed using transport support tools for long-distance transport. Compared to related technologies, this method effectively controls the processing precision throughout the entire production process of large-size grating support plates, avoiding stress concentration and plate deformation during lifting and transport.

Description

Technical Field

[0001] This invention relates to the field of reactor equipment manufacturing technology, and more specifically, to a method for producing a grid support plate for a large-size ethylene oxide reactor. Background Technology

[0002] As a core component in chemical production, the ethylene oxide reactor relies on a grid support plate to ensure precise positioning and stable operation of the heat exchange tubes. With the increasing scale of the chemical industry, the size of ethylene oxide reactors is continuously expanding, leading to a significant increase in the diameter and number of layers of the grid support plate. For example, some new reactors feature grid support plates with diameters exceeding eight meters and ten layers, placing stringent demands on manufacturing precision. These grid support plates are assembled from multiple individual grid strips, requiring strict control of overall flatness within minute tolerances. Furthermore, the multiple layers must allow the heat exchange tubes to smoothly penetrate all openings without external assistance, ensuring the reactor's heat transfer efficiency and structural stability.

[0003] However, existing production methods have systemic flaws when addressing the challenges of large-scale production: In the processing of individual grid strips, the selection of raw materials lacks standardization, dimensional tolerance control is too lenient, the flatness of the plates after cutting is not included in the control scope, and the accuracy of the slotting position is difficult to meet the process requirements; During assembly, due to the lack of dedicated positioning platforms and tooling, the arrangement of individual grid strips relies on manual experience, leading to the accumulation of positioning deviations, ordinary welding processes are prone to causing large-area thermal deformation, the randomness of the installation sequence further amplifies dimensional errors, and operations such as hammering or strong extrusion cause local irreversible deformation of the grid strips; The final inspection process lacks scientific standards and cannot fully verify the consistency of hole alignment accuracy and overall flatness; In addition, due to the weak structural rigidity of large-size grid support plates, stress concentration and center sagging are prone to occur during conventional hoisting operations, and the transport process suffers from bumps and uneven stress due to insufficient support, ultimately causing the plates to bend and twist, rendering the precision control results of the early manufacturing stage completely ineffective, seriously hindering the normal installation of heat exchange tubes, and thus threatening the operational safety and long-term reliability of the entire reactor. Summary of the Invention

[0004] The purpose of this invention is to provide a method for producing a grid support plate for a large-size ethylene oxide reactor. This method can effectively control the processing accuracy of the entire production process of the large-size grid support plate, avoid stress concentration and plate deformation during lifting and transportation, ensure the flatness and hole alignment accuracy of the grid support plate, and meet the assembly requirements of the large-size ethylene oxide reactor.

[0005] This invention provides a method for producing a large-size ethylene oxide reactor grid support plate, comprising the following steps: S1. Prepare single-piece grid strips, and carry out fully controlled processing of the single-piece grid strips in terms of material selection, dimensional tolerance, blanking flatness and grooving accuracy; S2. Place multiple finished single-piece grid strips on the assembly platform, and use positioning fixtures for precise positioning, locking and welding assembly to form an integral grid support plate. S3. After the grid support plate is assembled, single-layer precision self-inspection and multi-layer superposition alignment precision self-inspection are carried out in sequence. Only after the inspection is qualified can it be transferred to the subsequent process. S4. Use lifting tools to carry out balanced lifting operations on the inspected and qualified grating support plates to suppress stress concentration and plate deformation during the lifting process; S5. Use transport support tools to rigidly support and fix the grid support plate as a whole to complete the long-distance transportation, and keep the flatness and hole size accuracy of the grid support plate unchanged during the transportation process.

[0006] Optionally, step S1 specifically includes: selecting cold-rolled strip steel or cold-rolled sheet as the raw material for the single grating strip; limiting the thickness and width dimensional tolerances of the single grating strip to within the lower limit of the tolerance required by the drawing; controlling the flatness of the single grating strip after cutting to within 0.2mm; using a machine tool to perform grooving machining on the single grating strip, and using a gauge that has passed metrological verification to detect and control the positional tolerance of the grating groove.

[0007] Optionally, the positional tolerance of the grid groove is controlled within 0.1 mm.

[0008] Optionally, step S2 specifically includes: using the assembly platform with precision positioning holes to arrange the single grid strips; using stainless steel positioning pins to pass through the positioning holes on the assembly platform and the single grid strips to achieve positioning and fixation, and the stainless steel positioning pins shall not be removed before all welding processes are completed; and using laser spot welding to fix the single grid strips according to the positions marked on the drawings.

[0009] Optionally, the single grid strips are installed in an order that expands from the center of the grid support plate to both sides; for each single grid strip installed, a positioning tube is used to synchronously control the installation spacing and overall straightness of the single grid strips; hammering, strong squeezing or other external forces are prohibited during the entire assembly process to prevent local deformation of the grid strips.

[0010] Optionally, the positioning tube is a cylindrical positioning component that matches the aperture of the tube bundle in the ethylene oxide reactor, used to precisely define the spacing between adjacent individual grid strips and calibrate the overall installation straightness of the grid support plate.

[0011] Optionally, step S3 specifically includes: Perform single-layer self-inspection: Use a simulated tube insertion test at any random inspection point on the grid support plate. The tube is considered qualified if it can be smoothly inserted without external force. Perform multi-layer stacking self-inspection: Randomly select any four layers of the grid support plates that have passed the single-layer self-inspection and stack them together. Perform simulated pipe insertion test at any sampling point. The pipes can be smoothly inserted without external force and are considered qualified. The overall sampling inspection coverage area shall be no less than 30% of the total area of ​​the grid support plate.

[0012] Optionally, in step S4, the hoisting tool is an octagonal hoisting tool; the octagonal hoisting tool is an octagonal frame structure adapted to the shape of the grid support plate, and the octagonal frame structure is provided with eight hoisting connection points evenly distributed along the circumference.

[0013] Optionally, the eight lifting connection points of the octagonal lifting tool are respectively connected to the pre-set lifting lugs or reinforcing ribs of the grid support plate; during lifting, the weight of the grid support plate is distributed evenly at eight points to avoid the center of the plate sagging and bending deformation, and to maintain the overall flatness accuracy of the grid support plate.

[0014] Optionally, in step S5, the transport support tool adopts an annular support frame or a multi-point distributed support frame structure that matches the outer diameter of the grid support plate.

[0015] The present invention provides a method for producing a large-size ethylene oxide reactor grid support plate, which, compared with related technologies, has, but is not limited to, the following beneficial effects: The method for producing large-size ethylene oxide reactor grid support plates described in this invention effectively solves the problems of rough raw material tolerances, low processing precision, easy deformation during assembly, imperfect inspection standards, stress concentration during hoisting, and easy bending and twisting during transportation that exist in the traditional manufacturing of large-size ethylene oxide reactor grid support plates. This is achieved through controlled management of the entire process of preparation, assembly, inspection, hoisting, and transportation of individual grid strips. As a result, the overall flatness, hole size accuracy, and structural rigidity of the grid support plate are ensured, guaranteeing the smooth installation of the reactor heat exchange tubes and improving the overall reliability of the reactor operation. Attached Figure Description

[0016] Figure 1 This is a flowchart illustrating the production method of a large-size ethylene oxide reactor grid support plate according to an embodiment of the present invention. Detailed Implementation

[0017] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0018] In the description of this invention, the orientations or positional relationships indicated by terms such as "up," "down," "left," "right," "top," "bottom," "front," "back," "inner," and "outer" are based on the orientations or positional relationships shown in the accompanying drawings and are used only for the convenience of describing this invention. They are not intended to indicate or imply that the device referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as limiting the scope of protection of this invention.

[0019] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0020] In the description of this specification, references to terms such as "embodiment," "one embodiment," and "one implementation" indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or implementation is included in at least one embodiment or implementation of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or implementation. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or implementations.

[0021] like Figure 1 As shown, the method for producing a large-size ethylene oxide reactor grid support plate according to an embodiment of the present invention includes the following steps: S1. Prepare single-piece grid strips, and carry out fully controlled processing of the single-piece grid strips in terms of material selection, dimensional tolerance, blanking flatness and grooving accuracy; S2. Place multiple finished single-piece grid strips on the assembly platform, and use positioning fixtures for precise positioning, locking and welding assembly to form an integral grid support plate. S3. After the grid support plate is assembled, single-layer precision self-inspection and multi-layer superposition alignment precision self-inspection are carried out in sequence. Only after the inspection is qualified can it be transferred to the subsequent process. S4. Use lifting tools to carry out balanced lifting operations on the inspected and qualified grating support plates to suppress stress concentration and plate deformation during the lifting process; S5. Use transport support tools to rigidly support and fix the grid support plate as a whole to complete the long-distance transportation, and keep the flatness and hole size accuracy of the grid support plate unchanged during the transportation process.

[0022] In this embodiment, a single grid strip refers to the basic unit constituting the grid support plate of the ethylene oxide reactor. It is typically a slender strip-shaped metal component with slots or holes for mating with other components. The geometrical accuracy, surface flatness, and material uniformity of this single grid strip have a direct impact on the overall performance of the final grid support plate.

[0023] A grid support plate is an integral structure composed of multiple individual grid bars connected together. It is used to support the tube bundle inside an ethylene oxide reactor, ensuring the stability of the tube bundle and its heat exchange efficiency. The overall flatness, aperture accuracy, and structural rigidity of the grid support plate are its key performance indicators.

[0024] An assembly platform is a reference workbench used to support and position individual grid strips for assembling grid support panels. This assembly platform typically features high flatness and sufficient rigidity, and may be equipped with auxiliary positioning devices to ensure the accurate positioning of individual grid strips during assembly.

[0025] Positioning fixtures are auxiliary devices used to precisely position and fix individual grid strips during the assembly of grid support plates. These fixtures ensure that multiple individual grid strips are arranged and spaced according to design requirements, thereby guaranteeing the overall geometric accuracy of the grid support plate.

[0026] Lifting tools are specialized equipment used for lifting and moving large-sized grating support panels. The design of these tools aims to ensure even stress distribution on the grating support panels, preventing localized deformation or overall sagging due to stress concentration during lifting.

[0027] Transport support tools are specialized devices used to support and secure grating support plates during long-distance transport. These tools provide sufficient rigidity to resist bumps, vibrations, and impacts during transport, thereby maintaining the flatness and dimensional accuracy of the grating support plates.

[0028] Specifically, in step S1, single-piece grid strips are prepared. This preparation process includes selecting the material for the single-piece grid strip; for example, ordinary carbon steel or alloy steel can be selected based on strength requirements. Simultaneously, the dimensional tolerances of the single-piece grid strip are controlled, for example, by limiting them using conventional machining tolerance standards. The flatness after cutting is also controlled; for example, cutting is performed using a shearing machine or flame cutting, and preliminary leveling can be carried out. The grooving accuracy is also controlled; for example, grooving is completed using machining methods such as milling or wire cutting, and can be inspected using general-purpose measuring tools.

[0029] In step S2, multiple fabricated individual grid strips are placed on an assembly platform. This assembly platform can be a steel plate workbench with sufficient flatness. Then, positioning fixtures are used to precisely position and lock the individual grid strips; for example, simple clamps or positioning blocks are used to fix the individual grid strips in preset positions, and temporary spot welding can be performed to maintain their relative positions. Afterwards, these individual grid strips are assembled into a single integrated grid support plate by welding, for example, using manual arc welding or gas shielded welding.

[0030] In step S3, the assembled grid support plates undergo sequential single-layer precision self-inspection and multi-layer superimposed alignment precision self-inspection. Single-layer precision self-inspection can involve sampling measurements of local dimensions and hole spacing of the grid support plate, for example, using a measuring tape or calipers. Multi-layer superimposed alignment precision self-inspection can be performed by randomly selecting two grid support plates, stacking them, and then visually inspecting them or using a simple gauge to determine hole alignment. Only grid support plates that pass inspection can proceed to subsequent processes.

[0031] In step S4, a lifting tool is used to lift the inspected and qualified grating support plate under balanced stress. This lifting tool can be a multi-point lifting device composed of wire ropes or chains, and the lifting point positions can be initially adjusted according to the center of gravity of the grating support plate. The lifting operation aims to suppress stress concentration and plate deformation that may occur during the lifting process, for example, by lifting slowly and observing the plate's posture to maintain a balanced stress as much as possible.

[0032] In step S5, a transport support tool is used to rigidly support and fix the grating support plate as a whole, completing the long-distance transport. This transport support tool can be a simple frame structure built from timber, steel pipes, or structural steel, used to support the bottom of the grating support plate during transport. Simultaneously, the grating support plate is fixed to the support tool using straps or bolts to maintain the flatness and hole size accuracy during transport, for example, to prevent displacement or deformation caused by vehicle bumps or vibrations.

[0033] This invention effectively solves the problems of rough raw material tolerances, low processing precision, easy deformation during assembly, imperfect inspection standards, stress concentration during hoisting, and easy bending and twisting during transportation in the traditional manufacturing of grid support plates for large-size ethylene oxide reactors by controlling the entire process of preparation, assembly, inspection, hoisting, and transportation of single-piece grid bars. As a result, it ensures the overall flatness, hole size accuracy, and structural rigidity of the grid support plate, guarantees the smooth installation of the reactor heat exchange tubes, and improves the reliability of the entire reactor operation.

[0034] Optionally, step S1 specifically includes: selecting cold-rolled strip steel or cold-rolled sheet as the raw material for the single grating strip; limiting the thickness and width dimensional tolerances of the single grating strip to within the lower limit of the tolerance required by the drawing; controlling the flatness of the single grating strip after cutting to within 0.2mm; using a machine tool to perform grooving machining on the single grating strip, and using a gauge that has passed metrological verification to detect and control the positional tolerance of the grating groove.

[0035] In this embodiment, cold-rolled strip steel or cold-rolled sheet steel is selected as the raw material for the single grating bar, which ensures the material uniformity and dimensional stability of the grating bar from the source. Cold-rolled steel is rolled at room temperature, which has the characteristics of good surface quality, high dimensional accuracy, and excellent mechanical properties. Its thickness uniformity is also better, laying a solid foundation for subsequent precision processing. For example, depending on the working environment of the ethylene oxide reactor, such as high temperature, high pressure, or corrosive media, a specific grade of cold-rolled stainless steel strip steel or sheet steel can be selected to ensure that the grating bar has sufficient corrosion resistance and mechanical strength.

[0036] Meanwhile, limiting the thickness and width tolerances of individual grid strips to the lower limit of the tolerances required by the drawings means stricter control over the actual dimensions of the grid strips, making them closer to the ideal design dimensions. Strict control of these key dimensional tolerances is crucial to ensuring the fit accuracy between grid strips and the overall dimensional accuracy of the grid support plate. This can be achieved by requiring suppliers to provide high-precision materials during raw material procurement, or by using high-precision cutting equipment such as laser cutting or wire cutting in the internal processing stage, supplemented by an online measurement system for real-time monitoring and adjustment. For example, for thickness tolerances, micrometers or thickness gauges can be used for sampling or full inspection; for width tolerances, high-precision calipers or image measuring instruments can be used for inspection.

[0037] Furthermore, the unevenness of each individual grid strip after cutting is controlled within 0.2mm to ensure extremely high flatness. Significant unevenness in the cut grid strips will directly prevent them from fitting tightly together during subsequent assembly, affecting welding quality and the overall structural stability. To achieve this, low-stress cutting methods such as precision shearing or laser cutting can be used, followed by leveling treatment, such as roller leveling or tension leveling. Throughout the processing, care should be taken to avoid uneven heating or internal stress in the material to effectively prevent deformation of the grid strips.

[0038] Furthermore, using machine tools to groove individual grid bars is crucial to ensuring high precision and surface quality of the grooves. Machine tool processing, such as using milling machines or CNC machining centers, can precisely control the width, depth, position, and shape of the grooves, thereby ensuring the fitting accuracy between the grooves and the reactor tube bundle or adjacent grid bars. For example, a vertical machining center can be used to precisely control the tool path and feed rate through a preset CNC program, achieving high-precision groove machining.

[0039] Based on this, using metrologically calibrated gauges to inspect and control the positional tolerances of the grid slots is crucial for ensuring the overall hole position accuracy of the grid support plate. The positional accuracy of the grid slots directly determines the alignment accuracy between the grid support plate and the reactor tube bundle. By using specialized gauges certified by national or industry standards, such as specialized plug gauges, caliper gauges, coordinate measuring machines, or video measuring instruments, the position of each slot can be rigorously inspected and controlled to ensure compliance with design requirements. For example, a dedicated set of combined gauges can be designed to inspect the position and spacing of multiple slots simultaneously, thereby improving inspection efficiency and accuracy.

[0040] Optionally, the positional tolerance of the grid groove is controlled within 0.1 mm.

[0041] In this embodiment, the positional tolerance of the grid groove refers to the allowable deviation range of the actual position of the groove on a single grid bar from its theoretical design position. Controlling this tolerance within 0.1mm implies extremely high requirements for the machining accuracy of the grid groove. To achieve this stringent tolerance control, various technical means can be employed. For example, during the grooving process, a high-precision CNC machine tool can be selected, possessing micron-level positioning accuracy and repeatability, ensuring the accuracy of the groove position each time it is machined. Simultaneously, an online measurement system, such as a laser scanner or a high-precision vision inspection system, can be integrated to perform real-time or near-real-time measurements on each machined grid groove, and the measurement data can be fed back to the CNC system for closed-loop control, allowing for timely correction of machining parameters to ensure the positional tolerance is always maintained within the 0.1mm limit. Furthermore, the temperature and humidity of the machining environment must also be strictly controlled to reduce the impact of material thermal expansion and contraction on dimensional accuracy. In terms of inspection and control, in addition to using inspection tools that have passed metrological verification for random inspection, a coordinate measuring machine (CMM) can be introduced to perform precision measurement of full dimensions or key dimensions to ensure that the positional accuracy of all grid slots meets the requirements.

[0042] Optionally, step S2 specifically includes: using the assembly platform with precision positioning holes to arrange the single grid strips; using stainless steel positioning pins to pass through the positioning holes on the assembly platform and the single grid strips to achieve positioning and fixation, and the stainless steel positioning pins shall not be removed before all welding processes are completed; and using laser spot welding to fix the single grid strips according to the positions marked on the drawings.

[0043] In this embodiment, the assembly platform is the basic tooling used to support and position individual grid strips. An assembly platform with precision positioning holes is selected, the positional accuracy of which is strictly controlled and typically manufactured using high-precision CNC machining equipment to ensure that its height matches the grid strip arrangement on the design drawings. These positioning holes can be precisely laid out in advance according to the design dimensions of the grid support plate and the spacing of the individual grid strips, providing a reliable reference for subsequent installation of the individual grid strips.

[0044] Stainless steel locating pins are key components for precisely positioning and fixing individual grid strips. Stainless steel possesses excellent corrosion resistance and a certain level of strength, ensuring that the locating pins are not affected by heat deformation during welding and can withstand a certain clamping force. The locating pins pass through precision positioning holes in the assembly platform and corresponding holes on the individual grid strips, forming a rigid connection that precisely locks the individual grid strips in the preset position. It is emphasized that the stainless steel locating pins must not be removed before all welding processes are completed to ensure that the position of the individual grid strips remains stable throughout the entire welding process, avoiding displacement caused by welding thermal stress or external vibration, thereby guaranteeing the dimensional accuracy and geometry of the final grid support plate.

[0045] Laser spot welding is a high-energy-density welding technology with a small heat-affected zone. Compared to traditional welding methods, laser spot welding can achieve rapid and precise localized melting and solidification, effectively reducing welding heat input and thus significantly reducing welding deformation and residual stress. Spot welding according to the positions marked on the drawings means that the location, number, and sequence of welding points are carefully designed to optimize stress distribution and further control welding deformation. The purpose of spot welding is to initially fix individual grid strips without affecting overall accuracy, providing a stable structural foundation for subsequent full welding or finishing.

[0046] Optionally, the single grid strips are installed in an order that expands from the center of the grid support plate to both sides; for each single grid strip installed, a positioning tube is used to synchronously control the installation spacing and overall straightness of the single grid strips; hammering, strong squeezing or other external forces are prohibited during the entire assembly process to prevent local deformation of the grid strips.

[0047] In this embodiment, the individual grid strips are installed in a sequence that expands outwards from the center of the grid support plate. This means that during the assembly of the grid support plate, the individual grid strips are first installed from the geometric center of the plate, and then gradually expanded to the sides or perimeter, with the remaining individual grid strips installed sequentially. This outward expansion method helps to disperse and balance stresses that may be generated during assembly, preventing stress concentration in a particular area and thus reducing the risk of overall structural deformation. Simultaneously, it provides a stable reference for subsequent positioning and calibration.

[0048] For each individual grid strip installed, a positioning tube is used to synchronously control the installation spacing and overall straightness of the grid strip. The positioning tube is an auxiliary tool used to precisely control the spacing between individual grid strips and calibrate their straightness. After each individual grid strip is installed, the positioning tube is immediately inserted into a predetermined position between adjacent grid strips to ensure that the spacing meets design requirements. The introduction of the positioning tube allows for not only limiting and fixing via positioning pins during assembly, but also real-time, dynamic calibration and constraint of the installation spacing and the straightness of the grid strips. The positioning tube can be a high-precision machined cylindrical component, with its outer diameter matching the designed spacing between the grid strips, ensuring precise spacing definition after insertion.

[0049] Throughout the assembly process, hammering and strong compressive forces are strictly prohibited to prevent localized deformation of the grid bars. During the entire assembly of the grid support plate, the use of hammering, strong compressive forces, or other external forces that could cause localized stress concentration or plastic deformation of the grid bars is strictly forbidden. This is because each grid bar has undergone high-precision machining during manufacturing, and its dimensional tolerances and flatness are strictly controlled. Any improper external force may compromise these precision requirements, causing the grid bars to bend, twist, or become locally dented, thereby affecting the overall assembly accuracy and final performance of the grid support plate. Therefore, assembly operations should be performed gently and precisely to ensure that the grid bars are positioned and fixed under stress-free or low-stress conditions.

[0050] Optionally, the positioning tube is a cylindrical positioning component that matches the aperture of the tube bundle in the ethylene oxide reactor, used to precisely define the spacing between adjacent individual grid strips and calibrate the overall installation straightness of the grid support plate.

[0051] In this embodiment, the positioning tube is a cylindrical positioning component whose dimensions are precisely designed such that its outer diameter or related dimensions completely match the pore diameter of the tube bundle of an ethylene oxide reactor. This matching property enables the positioning tube to serve as a high-precision standard reference. When assembling the grid support plate, the positioning tube can be inserted into the reserved space between adjacent single grid strips. Due to its precise matching with the pore diameter of the tube bundle, the positioning tube can physically fix the distance between adjacent grid strips at the accurate value required by the design, thereby effectively preventing spacing deviation caused by welding stress, thermal deformation or operation errors. In addition, the positioning tube also functions to calibrate the overall installation flatness of the grid support plate. By inserting a plurality of said positioning tubes at different positions of the grid support plate and observing the arrangement of these positioning tubes, the overall flatness and straightness of the grid support plate can be monitored and adjusted in real time, ensuring its accuracy in three-dimensional space, thereby guaranteeing the geometric accuracy of the entire large-sized grid support plate.

[0052] Optionally, step S3 specifically includes: Performing single-layer self-inspection: carrying out a simulated tube loading test at any sampling point of the grid support plate, and it is qualified if the simulated tube can be inserted smoothly without external force; Performing multi-layer stacked self-inspection: randomly selecting four layers of said grid support plates that have passed the single-layer self-inspection to stack, carrying out the simulated tube loading test at any sampling point, and it is qualified if the simulated tube can be inserted smoothly without external force; The overall sampling inspection coverage area is not less than 30% of the total area of the grid support plate.

[0053] In this embodiment, single-layer self-inspection is performed. A simulated tube loading test is conducted with a simulated tube at any sampling point of the grid support plate. The simulated tube is generally a cylindrical component matched with the pore diameter of the ethylene oxide reactor tube bundle, and is used to simulate the actual installation process of the tube bundle. If the simulated tube can be inserted smoothly without any external force, the point is considered qualified. This measure is intended to ensure that the pore position accuracy and local flatness of each individual grid support plate meet the requirements, and avoid dimensional deviation inside the single plate.

[0054] Multi-layer stacked self-inspection is performed. On the basis of passing the single-layer self-inspection, any four layers of grid support plates are randomly selected for stacking. Then, at any sampling point of the stacked grid support plates, the simulated tube loading test is carried out again. Similarly, if the simulated tube can be inserted smoothly without external force, the stacked layer is considered qualified. This step is intended to simulate the actual installation state of the grid support plates in the reactor, check the cumulative error and overall alignment accuracy after multi-layer stacking, and ensure that jamming or failure to insert will not occur when the tube bundle is actually installed.

[0055] To ensure the comprehensiveness and reliability of the inspection, the overall sampling coverage area should be no less than 30% of the total area of ​​the grating support plate. This means that the selection of inspection points should be sufficiently representative, covering most of the area of ​​the grating support plate, so as to effectively detect any potential local defects or overall deformation.

[0056] Optionally, in step S4, the hoisting tool is an octagonal hoisting tool; the octagonal hoisting tool is an octagonal frame structure adapted to the shape of the grid support plate, and the octagonal frame structure is provided with eight hoisting connection points evenly distributed along the circumference.

[0057] In this embodiment, the octagonal lifting tool refers to a lifting auxiliary device with an eight-sided geometry. Its design aims to provide more uniform support and a more stable lifting posture than traditional four-point or two-point lifting, making it particularly suitable for large, easily deformable plate-shaped components. Its octagonal shape can better fit or enclose circular, square, or near-circular grid support plates, thereby providing more comprehensive support during lifting.

[0058] The octagonal lifting tool is an octagonal frame structure adapted to the shape of the grating support plate. This "octagonal frame structure" means that the main body of the lifting tool is composed of interconnected rods or plates, forming a closed or semi-closed structure with eight corners and eight sides. This frame structure is typically made of high-strength steel or other structural materials to ensure sufficient rigidity and strength when bearing the weight of the grating support plate, preventing deformation and effectively transferring and distributing the load. The internal space of the frame is usually open to facilitate the placement and connection of the grating support plate. "Adapted to the shape of the grating support plate" means that the size and shape of the octagonal lifting tool match the outer contour of the grating support plate to be lifted. This adaptation ensures that the lifting tool can tightly enclose or support the grating support plate, allowing it to be stably supported during lifting, avoiding swaying, tilting, or excessive localized stress caused by dimensional mismatch, thus effectively preventing deformation of the plate during lifting.

[0059] By employing this octagonal lifting tool, its octagonal frame structure provides a wider support area and a more uniform stress distribution. When the grating support plate is lifted, its self-weight is effectively distributed through eight evenly distributed connection points, avoiding localized stress concentrations that may occur with traditional lifting methods. This balanced stress design significantly suppresses center sagging, edge warping, or overall bending deformation that may occur during the lifting process of the grating support plate. This ensures that the flatness and hole size accuracy of the grating support plate can be effectively maintained when it is transferred to subsequent processes or transported, providing a reliable guarantee for subsequent precise installation and use.

[0060] Optionally, the eight lifting connection points of the octagonal lifting tool are respectively connected to the pre-set lifting lugs or reinforcing ribs of the grid support plate; during lifting, the weight of the grid support plate is distributed evenly at eight points to avoid the center of the plate sagging and bending deformation, and to maintain the overall flatness accuracy of the grid support plate.

[0061] In this embodiment, the eight lifting connection points on the octagonal lifting tool are pre-designed and precisely machined interfaces for connecting with the grating support plate. These points are evenly distributed along the circumference of the octagonal frame, ensuring the symmetry and balance of the connection. The pre-installed lifting lugs or reinforcing ribs on the grating support plate are structural components integrated or welded during the manufacturing process. The lifting lugs are typically ring-shaped or U-shaped metal parts with sufficient strength to withstand lifting loads; the reinforcing ribs are additional structures added to the plate to enhance local rigidity and can be designed with connecting holes or connecting surfaces. The positions of these lifting lugs or reinforcing ribs are precisely matched with the lifting connection points of the octagonal lifting tool, ensuring the reliability and stability of the connection. Corresponding connection refers to the tight fixing between the connection points of the lifting tool and the lifting lugs or reinforcing ribs on the grating support plate using bolts, pins, or other detachable or semi-permanent connection methods to ensure effective force transmission and connection strength during lifting.

[0062] During lifting operations, the self-weight of the grating support plate is evenly distributed across the eight lifting connection points of the octagonal lifting tool through the aforementioned connection method. This uniform force distribution mechanism means that the load borne by each connection point is approximately equal, avoiding stress concentration in localized areas due to excessive force. Achieving eight-point uniform force distribution can be ensured by accurately calculating the structural stiffness of the lifting tool, the length of the slings, and the geometric position of the connection points. For example, slings of equal length can be used to connect the eight connection points of the lifting tool to the crane hook, thus naturally forming a uniform force distribution state during lifting. Due to their size and weight, large-sized grating support plates are prone to sagging or bending in the central area or areas of lower stress when lifted using only a few points or non-uniform force distribution. Through eight-point uniform force distribution, the overall force state of the grating support plate tends to be balanced, and its self-weight is effectively supported, thus significantly suppressing central sagging and overall bending deformation of the plate due to gravity during lifting. Flatness accuracy is a crucial indicator for the grid support plate, a key component inside the reactor, directly affecting the installation accuracy and operational stability of the reactor tube bundle. Through the aforementioned uniformly distributed lifting method, the grid support plate maintains its initial flatness throughout the lifting process, preventing flatness degradation caused by improper lifting operations. This is essential for ensuring the smooth installation of the grid support plate in subsequent processes and ultimately guaranteeing the performance of the ethylene oxide reactor.

[0063] Optionally, in step S5, the transport support tool adopts an annular support frame or a multi-point distributed support frame structure that matches the outer diameter of the grid support plate.

[0064] In this embodiment, the transport support tool is specifically designed for large-size grating support plates, providing stable and rigid support and fixation during long-distance transport to effectively resist external stress and ensure that the geometric accuracy of the plate is not affected. The tool matches the outer diameter of the grating support plate, meaning its design dimensions and shape are customized according to the actual outer diameter of the specific grating support plate. This precise matching is key to achieving effective support and preventing localized stress concentration or insufficient support. The annular support frame is typically assembled from high-strength metal profiles (such as steel or aluminum alloy) through welding or bolting, with its internal or external contours closely fitting the outer diameter of the grating support plate. This frame provides continuous or quasi-continuous support along the entire outer circumference of the grating support plate, evenly distributing the plate's own weight and dynamic loads generated during transport, thereby effectively suppressing bending, twisting, or flatness changes during transport. Furthermore, the multi-point distributed support frame structure is another effective support method, which supports the plate by setting multiple discrete but precisely calculated and arranged support points on the bottom or sides of the grating support plate. These support points are typically connected into an integral frame by pillars, blocks, or beams to ensure that each support point can provide sufficient support force, and the distribution of support force can minimize the deformation of the plate, which is especially suitable for grid support plates with complex shapes or special internal structural requirements.

[0065] By employing a ring-shaped support frame or a multi-point distributed support frame structure that matches the outer diameter of the grid support plate as the transport support tool, comprehensive and uniform rigid support can be provided for large-sized grid support plates. This customized support method avoids the problems of local stress concentration or insufficient support that may occur in traditional transportation methods, thereby effectively suppressing deformation of the grid support plate due to its own weight, vibration, or impact during long-distance transportation, such as a decrease in flatness and deviation in hole size accuracy. This ensures that the grid support plate, which has undergone precision machining, assembly, and inspection in the early stage, maintains its key geometric accuracy and functionality intact when it arrives at the installation site, greatly reducing transportation risks and ensuring the smooth installation of subsequent reactor tube bundles and the overall operational reliability of the equipment.

[0066] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A method for producing a large-size ethylene oxide reactor grid support plate, characterized in that, Includes the following steps: S1. Prepare single-piece grid strips, and carry out fully controlled processing of the single-piece grid strips in terms of material selection, dimensional tolerance, blanking flatness and grooving accuracy; S2. Place multiple finished single-piece grid strips on the assembly platform, and use positioning fixtures for precise positioning, locking and welding assembly to form an integral grid support plate. S3. After the grid support plate is assembled, single-layer precision self-inspection and multi-layer superposition alignment precision self-inspection are carried out in sequence. Only after the inspection is qualified can it be transferred to the subsequent process. S4. Use lifting tools to carry out balanced lifting operations on the inspected and qualified grating support plates to suppress stress concentration and plate deformation during the lifting process; S5. Use transport support tools to rigidly support and fix the grid support plate as a whole to complete the long-distance transportation, and keep the flatness and hole size accuracy of the grid support plate unchanged during the transportation process.

2. The method for producing a large-size ethylene oxide reactor grid support plate according to claim 1, characterized in that, Step S1 specifically includes: selecting cold-rolled strip steel or cold-rolled sheet as the raw material for the single grating strip; limiting the thickness and width dimensional tolerances of the single grating strip to within the lower limit of the tolerance required by the drawing; controlling the flatness of the single grating strip after cutting to within 0.2mm; using a machine tool to perform grooving machining on the single grating strip, and using a qualified inspection tool to detect and control the positional tolerance of the grating groove.

3. The method for producing a large-size ethylene oxide reactor grid support plate according to claim 2, characterized in that, The positional tolerance of the grid groove is controlled within 0.1mm.

4. The method for producing a large-size ethylene oxide reactor grid support plate according to claim 2, characterized in that, Step S2 specifically includes: using the assembly platform with precision positioning holes to arrange the single grid strips; using stainless steel positioning pins to pass through the positioning holes on the assembly platform and the single grid strips to achieve positioning and fixation, and the stainless steel positioning pins must not be removed before all welding processes are completed; and using laser spot welding to fix the single grid strips according to the positions marked on the drawings.

5. The method for producing a large-size ethylene oxide reactor grid support plate according to claim 4, characterized in that, The single grid strips are installed in a sequence that expands from the center of the grid support plate to both sides; for each single grid strip installed, a positioning tube is used to synchronously control the installation spacing and overall straightness of the single grid strips. During the entire assembly process, hammering and strong squeezing forces are prohibited to prevent local deformation of the grid strips.

6. The method for producing a large-size ethylene oxide reactor grid support plate according to claim 1, characterized in that, The positioning tube is a cylindrical positioning component that matches the aperture of the tube bundle in the ethylene oxide reactor. It is used to precisely define the spacing between adjacent individual grid strips and to calibrate the overall installation straightness of the grid support plate.

7. The method for producing a large-size ethylene oxide reactor grid support plate according to claim 1, characterized in that, Step S3 specifically includes: Perform single-layer self-inspection: Use a simulated tube insertion test at any random inspection point on the grid support plate. The tube is considered qualified if it can be smoothly inserted without external force. Perform multi-layer stacking self-inspection: Randomly select any four layers of the grid support plates that have passed the single-layer self-inspection and stack them together. Perform simulated pipe insertion test at any sampling point. The pipes can be smoothly inserted without external force and are considered qualified. The overall sampling inspection coverage area shall be no less than 30% of the total area of ​​the grid support plate.

8. The method for producing a large-size ethylene oxide reactor grid support plate according to claim 1, characterized in that, In step S4, the hoisting tool is an octagonal hoisting tool; the octagonal hoisting tool is an octagonal frame structure adapted to the shape of the grid support plate, and the octagonal frame structure is provided with eight hoisting connection points evenly distributed along the circumference.

9. The method for producing a large-size ethylene oxide reactor grid support plate according to claim 8, characterized in that, The eight lifting connection points of the octagonal lifting tool are respectively connected to the pre-set lifting lugs or reinforcing ribs of the grid support plate; during lifting, the weight of the grid support plate is distributed evenly at eight points to avoid the center of the plate sagging and bending deformation, and to maintain the overall flatness accuracy of the grid support plate.

10. The method for producing a large-size ethylene oxide reactor grid support plate according to claim 1, characterized in that, In step S5, the transport support tool adopts a ring support frame or a multi-point distributed support frame structure that matches the outer diameter of the grid support plate.

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