A method for installing a converter shell with limited height of a plant

Abstract

The present application relates to the technical field of converter equipment installation construction, and mainly relates to a converter shell installation construction method with limited height of workshop, characterized by lowering the height of the converter stand column, breaking through the limitation of the net height of the workshop and the lifting height of the crane, and realizing the integral shell one-time complete hoisting into position. Compared with the prior art, the present application completely abandons the traditional split hoisting and on-site assembly welding construction mode, does not need to perform split welding and assembly of the shell, greatly reduces the construction difficulty, effectively guarantees the concentricity of the shell installation, welding and assembly quality, adapts to the construction scene with limited height of the workshop, is simple and efficient in construction process, greatly shortens the construction period, reduces the on-site operation time, reduces the equipment rental and labor cost, and has remarkable economic benefits. Without the need of large-tonnage chain crane lifting assembly, high-altitude complex welding operation, simplified construction process, reduced high-risk operation links, greatly reduced construction difficulty, labor cost and safety hazards.

Description

Technical Field

[0001] This invention relates to the field of converter equipment installation and construction technology, and mainly to a method for installing and constructing a converter shell in a plant with limited height. Background Technology

[0002] Large steelmaking converters are core and critical equipment in steel production. The installation accuracy of the converter shell directly determines the subsequent operational stability, service life, and production safety of the converter. The current conventional installation process for large converters involves prefabricating a receiving platform frame with high and low platform columns on a steel ladle car. Hydraulic jacks are then installed at the top of the lower platform of the frame columns. After pre-installing the support rings and bearing seats, the entire furnace shell is hoisted into the support rings. The furnace shell and support rings are then secured at three points, and the entire assembly is towed to the converter foundation. However, in older plants and renovation projects, there are common problems such as insufficient net height and limited lifting height of the converter's overhead crane. The crane's lifting height cannot meet the conventional installation requirements for directly hoisting the entire furnace shell to the design elevation and embedding it into the support rings.

[0003] Currently, the industry only has one alternative construction method for this restricted scenario: a construction process involving the separate hoisting and on-site welding of the furnace shell. First, the lower part of the furnace shell is hoisted to the receiving platform. Then, the upper and middle parts of the furnace shell are welded together on a prefabricated platform before being hoisted to the receiving platform. Finally, a large-tonnage chain crane lifts the lower part of the furnace shell and assembles it with the middle and upper structures on-site. This traditional separate construction process has the following significant drawbacks: First, the construction procedures are cumbersome, hoisting and assembly are extremely difficult, and the risks of working at heights and in confined spaces are high. Second, the on-site separate welding environment is poor, welding stress is difficult to control, and welding deformation is very likely to occur, making it impossible to guarantee the welding quality of the furnace shell. Third, manual assembly has low precision, and the overall concentricity and roundness of the furnace shell are difficult to meet design and specification requirements, leading to vibration, uneven wear, and other problems during subsequent equipment operation, seriously affecting the operational stability of the converter equipment.

[0004] Therefore, there is an urgent need to develop a converter shell installation method that is suitable for scenarios with limited factory height, does not require separate welding, has high installation accuracy, and is safe and efficient in construction, so as to solve many shortcomings of existing technologies. Summary of the Invention

[0005] The purpose of this invention is to provide a method for installing converter shells in factories with limited height. It addresses the shortcomings of existing technologies and solves the technical problems of the inability to directly hoist the entire furnace shell into place, the difficulty and poor quality of the separate welding process, and the inability to guarantee concentricity under the current factory height restriction conditions. The invention enables the entire furnace shell to be hoisted into place in one go, with precise adjustment and positioning, which greatly improves the construction quality and efficiency.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A method for installing a converter shell in a factory building with limited height is characterized by overcoming the limitations of factory building height and crane lifting height by reducing the height of the furnace support columns, thus achieving a one-time complete hoisting and placement of the entire furnace shell. The method includes the following construction steps: S1. Prefabricated furnace receiving platform frame: The furnace receiving platform frame is prefabricated on two steel ladle cars. The furnace receiving platform frame is equipped with four columns, each of which has a high column head and a low column head. The overall height of the four columns meets the limit height requirement for the complete hoisting of the furnace shell into the support ring. A hydraulic jack is installed at the top of the low column head of each of the four columns. The four hydraulic jacks are arranged in a rectangular symmetrical manner. S2. Pre-installation of supporting components: The support ring on the converter shell and the bearing seats at both ends of the converter are pre-installed and fixed on the furnace receiving platform, and the positioning and calibration are completed. S3. Integral furnace shell hoisting and positioning: Using the bridge crane in the converter span, the complete integral furnace shell is hoisted into the support ring in one go, completing the initial placement and positioning of the furnace shell; S4. Fixed connection components: Three sets of support points are installed between the furnace shell and the support ring. The support ring and the furnace shell are rigidly connected and fixed through the three-point structure to form an integral assembly structure. S5. Staged Lifting and Adjustment: The furnace shell and support ring are lifted as a whole by four hydraulic jacks simultaneously. When the hydraulic jacks reach their maximum stroke and can no longer lift, the furnace shell is lifted in stages by alternately adding or removing flat pads between the high and low jacks until it is accurately lifted to the designed installation elevation. S6. Overall towing and positioning: Using a winch to pull the molten steel ladle car, the molten steel ladle car, furnace platform frame, furnace shell and support ring assembly structure are simultaneously towed to the converter foundation position to complete the precise positioning and installation.

[0007] In step S1, the reduction in column height is precisely calculated based on the effective hoisting height of the factory building, the maximum lifting height of the bridge crane, and the overall furnace shell dimensions, ensuring that the entire furnace shell is hoisted into the support ring without obstruction or collision.

[0008] In step S4, the three support points are evenly distributed at the assembly gap between the furnace shell and the support ring. After assembly, the concentricity is initially checked to ensure that the coaxiality error between the furnace shell and the support ring is controlled within the allowable range of the specification, with an error range of ±1mm.

[0009] In step S5, the four hydraulic jacks adopt a synchronous lifting control mode. During the lifting process, the horizontality and verticality of the furnace shell are monitored in real time, and the single lifting height does not exceed 80% of the effective stroke of the jack.

[0010] In step S5, the specific operation of the step-by-step lifting is as follows: release the hydraulic jacks at the corresponding positions symmetrically in pairs, lay flat pads and then reset the jacks to bear the force, alternately and in turn to complete the padding of the four columns, and keep the furnace shell level, without deviation or tilting throughout the process.

[0011] In step S6, the overall dragging process is carried out at a constant and slow speed. Before dragging, the connection firmness of the overall assembly structure should be checked to prevent the components from shifting or loosening during the dragging process.

[0012] The thickness of the flat pad is 15-20mm, and the selected specifications are consistent.

[0013] Compared with the prior art, the beneficial effects of the present invention are: 1. Adaptable to height-restricted working conditions and highly versatile: By reducing the height of the furnace platform support columns, the limitations of factory net height and crane lifting height are overcome, enabling the entire furnace shell to be hoisted into place in one go. This completely eliminates the traditional construction mode of separate hoisting and on-site welding, and is perfectly adapted to height-restricted construction scenarios such as old factories and renovation projects. 2. Significantly improved construction quality: The furnace shell is prefabricated and welded as a whole in the factory, avoiding the quality defects of welding in the confined space on site and eliminating the problem of deformation during on-site assembly; combined with the hydraulic synchronous jacking + alternating shim plate adjustment process, the elevation, levelness and concentricity of the furnace shell are precisely controlled, and the installation accuracy is far higher than that of traditional processes, ensuring the long-term stable operation of the converter. 3. Reduced construction difficulty and safety risks: No need for large-tonnage chain cranes for lifting and assembly, no need for complex high-altitude welding operations, simplifying construction procedures, reducing high-risk operation links, and significantly reducing construction difficulty, labor costs and safety hazards; 4. High construction efficiency and good economy: The construction process is simple and efficient, with overall hoisting, overall adjustment and overall dragging into place. This greatly shortens the construction period, reduces on-site operation time, and reduces equipment rental and labor costs, resulting in significant economic benefits. Attached Figure Description

[0014] Figure 1 This is a three-dimensional schematic diagram of the furnace platform according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the furnace body lifting in an embodiment of the present invention; Figure 3 This is a schematic diagram of the hoisting and transportation of the converter support ring and furnace body in an embodiment of the present invention; In the diagram: 1-steel ladle car, 2-furnace platform frame, 3-hydraulic jack, 4-high column head, 5-low column head, 6-converter shell, 7-support ring, 8-bearing seat, 9-lifting tool, 10-bridge crane, 11-flat pad. Detailed Implementation

[0015] The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0016] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the specific embodiments used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the specific embodiments described below are some embodiments of the present invention. For those skilled in the art, other specific embodiments can be obtained based on these specific embodiments without creative effort.

[0017] See Figure 1-3 This is a schematic diagram of an embodiment of the construction method for installing a converter shell in a factory building with limited height, based on an example of a converter renovation project in an old steel plant. The embodiment addresses the practical problems of limited clear height across the converter span and the inability of the maximum lifting height of the bridge crane to meet the conventional requirements for hoisting and positioning the entire furnace shell. This embodiment overcomes the limitations of factory height and crane lifting height by reducing the height of the furnace support column, enabling the complete hoisting and positioning of the entire furnace shell in one go. The specific construction steps are as follows: S1. Prefabricated furnace receiving platform: A furnace receiving platform 2 is erected on two steel ladle cars 1. The furnace receiving platform 2 is equipped with four columns, each column having a high column head 4 and a low column head 5. Based on the lifting height (a) of the bridge crane 10, the net height (b) of the steel ladle car 1, the net height (d) of the support ring, the outer diameter of the converter shell 6, and the hoisting safety clearance (e), the overall height (c) of the column 3 is calculated, which should satisfy abcd>e, ensuring that the entire converter shell can be hoisted intact into the support ring 7 by the lifting device 9 without collision. A 500t hydraulic jack 3 is installed on the top of each of the four columns. The four hydraulic jacks 3 are arranged in a rectangular symmetrical pattern. The synchronous lifting performance of the jacks is adjusted to ensure stable lifting.

[0018] S2. Pre-installation of supporting components: Install and fix the support ring 7 and the bearing seats 8 at both ends of the converter in the preset positions of the furnace receiving platform 2 in sequence. Note that the bearing seat 8 includes the active side bearing seat and the driven side bearing seat. Pay attention to distinguishing the direction. Use a level and theodolite to calibrate the levelness and center position of the support ring to ensure that the pre-installation accuracy meets the assembly standard and complete the positioning calibration. S3. Hoisting and positioning of the integral furnace shell: Using the bridge crane 10 in the converter span of the workshop, the prefabricated integral converter shell 6 is hoisted in one go and placed stably inside the support ring 7, leaving a uniform assembly gap to complete the initial positioning.

[0019] S4. Fixed connection components: Three sets of support points are evenly arranged between the converter shell 6 and the support ring 7, and rigid connection is made by bolt fastening to complete the integrated fixing of the converter shell 6 and the support ring 7. The concentricity of the converter shell 6 is initially calibrated, and the deviation is controlled within ±1mm to form an overall assembly structure. S5. Staged Lifting and Adjustment: Start four hydraulic jacks 3 to lift the converter shell 6 and support ring 7 as a whole, keeping the lifting speed uniform and the force consistent. The lifting height of each lift should be controlled at 70% of the jack stroke. When the jacks reach their maximum stroke and can no longer lift, use a 20mm standard flat pad 11 to alternately lay the pads. Loosen the jacks diagonally, lay the pads, and then reset the force. Lift the converter shell step by step, repeatedly checking the elevation, levelness, and concentricity of the converter shell until the converter shell completely reaches the design installation elevation. Fix the pads and lock the lifting state.

[0020] S6. Overall dragging and positioning: After thoroughly checking the connection of each component and the installation accuracy of the furnace shell, start the winch to pull the molten steel ladle car 1 at a low and uniform speed, and smoothly drag the overall assembly structure along the ladle car track to the center position of the converter foundation, accurately align and fix it, and complete all installation construction.

[0021] After the completion of this embodiment, the elevation deviation, levelness deviation, and concentricity deviation of the converter shell are all better than the national construction specifications and design requirements. There are no on-site welding defects, the construction period is shortened by more than 40% compared with the traditional split process, there are zero accidents during construction, and the installation quality and construction efficiency are significantly improved.

[0022] The construction method of this invention has a clear process and is easy to operate. It does not require modification of the factory building or large hoisting equipment. By simply optimizing the frame structure and jacking process, it can achieve high-precision and high-efficiency installation of large converter shells in height-restricted scenarios. It can be widely used in the renovation of old steel plant buildings and the installation of new converters in confined spaces, and has strong industrial practicality and promotion value.

[0023] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for installing the shell of a converter in a factory building with limited height, characterized in that, By reducing the height of the furnace platform support columns, the limitations of the plant's net height and crane lifting height are overcome, enabling the entire furnace shell to be hoisted into place in one go. The specific construction steps include the following: S1. Prefabricated furnace receiving platform frame: The furnace receiving platform frame is prefabricated on two steel ladle cars. The furnace receiving platform frame is equipped with four columns, each of which has a high column head and a low column head. The overall height of the four columns meets the limit height requirement for the complete hoisting of the furnace shell into the support ring. A hydraulic jack is installed at the top of the low column head of each of the four columns. The four hydraulic jacks are arranged in a rectangular symmetrical manner. S2. Pre-installation of supporting components: The support ring on the converter shell and the bearing seats at both ends of the converter are pre-installed and fixed on the furnace receiving platform, and the positioning and calibration are completed. S3. Integral furnace shell hoisting and positioning: Using the bridge crane in the converter span, the complete integral furnace shell is hoisted into the support ring in one go, completing the initial placement and positioning of the furnace shell; S4. Fixed connection components: Three sets of support points are installed between the furnace shell and the support ring. The support ring and the furnace shell are rigidly connected and fixed through the three-point structure to form an integral assembly structure. S5. Staged Lifting and Adjustment: The furnace shell and support ring are lifted as a whole by four hydraulic jacks simultaneously. When the hydraulic jacks reach their maximum stroke and can no longer lift, the furnace shell is lifted in stages by alternately adding or removing flat pads between the high and low jacks until it is accurately lifted to the designed installation elevation. S6. Overall towing and positioning: Using a winch to pull the molten steel ladle car, the molten steel ladle car, furnace platform frame, furnace shell and support ring assembly structure are simultaneously towed to the converter foundation position to complete the precise positioning and installation.

2. The method for installing a converter shell in a factory building with limited height according to claim 1, characterized in that, In step S1, the reduction in column height is precisely calculated based on the effective hoisting height of the factory building, the maximum lifting height of the bridge crane, and the overall furnace shell dimensions, ensuring that the entire furnace shell is hoisted into the support ring without obstruction or collision.

3. The method for installing a converter shell in a factory building with limited height according to claim 1, characterized in that, In step S4, the three support points are evenly distributed at the assembly gap between the furnace shell and the support ring. After assembly, the concentricity is initially checked to ensure that the coaxiality error between the furnace shell and the support ring is controlled within the allowable range of the specification, with an error range of ±1mm.

4. The method for installing a converter shell in a factory building with limited height according to claim 1, characterized in that, In step S5, the four hydraulic jacks adopt a synchronous lifting control mode. During the lifting process, the horizontality and verticality of the furnace shell are monitored in real time, and the single lifting height does not exceed 80% of the effective stroke of the jack.

5. The method for installing a converter shell in a factory building with limited height according to claim 1, characterized in that, In step S5, the specific operation of the step-by-step lifting is as follows: release the hydraulic jacks at the corresponding positions symmetrically in pairs, lay flat pads and then reset the jacks to bear the force, alternately and in turn to complete the padding of the four columns, and keep the furnace shell level, without deviation or tilting throughout the process.

6. The method for installing a converter shell in a factory building with limited height according to claim 1, characterized in that, In step S6, the overall dragging process is carried out at a constant and slow speed. Before dragging, the connection firmness of the overall assembly structure should be checked to prevent the components from shifting or loosening during the dragging process.

7. The method for installing a converter shell in a factory building with limited height according to claim 1, characterized in that, The thickness of the flat pad is 15-20mm, and the selected specifications are consistent.

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