A method for repairing a blast furnace by in-situ holding of a small frame when replacing a furnace shell

Abstract

This invention relates to the field of equipment maintenance technology, and in particular to a blast furnace maintenance construction method that maintains the small frame in situ during furnace shell replacement. The method includes the following steps: (1) removing equipment from the small frame; (2) establishing a new small frame support system; (3) separating the small frame from the furnace shell; (4) removing the old furnace shell; and (5) connecting the new furnace shell to the small frame. First, the small frame is connected to the furnace top frame through a new support system. Then, the small frame is completely separated from the furnace shell, and the replaced furnace shell is reconnected to the small frame. When replacing the furnace shell, there is no need to move the small frame. Compared with traditional construction methods, this reduces construction costs and improves construction efficiency.

Description

Technical Field

[0001] This invention relates to the field of equipment maintenance technology, and in particular to a blast furnace maintenance construction method that keeps the small frame in place during furnace shell replacement. Background Technology

[0002] The small frame inside the blast furnace is an independent, multi-layered steel structure located inside or above the large frame of the furnace top. It is used to support the receiving hopper, weighing hopper, upper and lower sealing valves, pressure equalization or venting system, furnace top inspection and maintenance trolley, hydraulic lubrication station, etc., of the bell-less furnace top. Unlike the large frame of the furnace top that supports the furnace shell and the furnace top platform, the small frame is a dedicated support for the charging system. In conventional blast furnace design, the small frame belongs to the bell-less furnace top system and is rigidly connected to the furnace shell flange (a combination of welding and high-strength bolts). It is mostly a four-column rectangular multi-layered structure.

[0003] During blast furnace ironmaking, the furnace shell is prone to damage due to complex operating conditions and high temperatures, requiring frequent replacement and maintenance. Since the small frame is directly connected to the blast furnace shell, during routine blast furnace maintenance, when replacing the top section of the shell, the small frame must be removed first before the shell can be dismantled. After the shell replacement is completed, the small frame needs to be reinstalled, resulting in long construction periods and high operating costs. Summary of the Invention

[0004] This invention provides a blast furnace maintenance construction method that keeps the small frame in place when replacing the furnace shell. First, the small frame is connected to the large frame of the furnace top through a new support system. Then, the small frame is completely separated from the furnace shell. The replaced furnace shell is then reconnected to the small frame. The small frame does not need to be moved when replacing the furnace shell. Compared with traditional construction methods, this reduces construction costs and improves construction efficiency.

[0005] To achieve the above objectives, the present invention employs the following technical solution: A blast furnace maintenance method that preserves the small frame in situ during furnace shell replacement includes the following steps: (1) Removal of equipment from the small frame: All equipment supported on the small frame is removed, that is, the additional load on the small frame is removed, leaving only the main body of the small frame; the main body of the small frame includes multiple columns and multiple crossbeams connecting the columns. (2) Establish a new small framework support system: The furnace top frame is modified. The furnace top frame consists of frame columns and a platform. The small frame is located inside the furnace top frame. A platform is set on top of the small frame. The platform consists of platform beams and platform slabs. Two parallel steel beams are added at the bottom of the platform directly above the small frame. The two ends of the steel beams are connected to the platform beams respectively. A connecting column is installed at the top of the small frame and above each column of the small frame. The top of the connecting column is fixed to the bottom of the steel beam, and the bottom of the connecting column is fixed to the top of the column of the small frame. Cross supports are installed between each connecting column; T-shaped supports are installed on the outer side of the connecting columns on both sides. The T-shaped supports consist of long diagonal supports and short diagonal supports. The lower end of the long diagonal support is connected to the bottom of the corresponding column, and the upper end of the long diagonal support is connected to the platform beam; the upper end of the short diagonal support is connected to the steel beam, and the lower end of the short diagonal support is connected to the middle of the long diagonal support. (3) Separation of the small frame from the furnace shell: Remove the connection between the small frame and the furnace shell to completely separate the small frame from the furnace shell. The separated small frame is then supported by the large frame on the furnace top. (4) Remove the old furnace shell: The old furnace shell at the top of the blast furnace was dismantled in sections. After the old furnace shell was dismantled, the horizontal position, elevation and verticality of the small frame were re-measured to ensure that the deviation between each index and the initial design value was ≤3mm. (5) New furnace shell and connection to the small frame; Install the new furnace shell according to the design requirements. After the new furnace shell is installed and adjusted in place, reconnect and fix the small frame to the new furnace shell.

[0006] In step (1), the equipment carried on the small frame includes a bellless gearbox, a cloth chute and its tilting and rotating mechanism, a material flow regulating valve, an upper sealing valve, a lower sealing valve, and a receiving tank.

[0007] In step (2), the steel beams and connecting columns are made of H-beams, and the cross supports and T-supports are made of angle steel.

[0008] In step (2), the small frame is a rectangular frame structure with 4 columns, and correspondingly, 4 connecting columns are also provided; the cross support is located between 2 connecting columns on the same side with a small spacing, and the plane of the T-shaped support is perpendicular to the plane of the cross support.

[0009] In step (2), when there is no platform beam at the upper end of the long inclined support, a support beam is added on the platform, and the two ends of the support beam are connected to the platform beam respectively, and the upper end of the long inclined support is connected to the support beam.

[0010] The small frame is connected to the furnace shell by high-strength bolts.

[0011] Compared with the prior art, the beneficial effects of the present invention are: (1) When replacing the furnace shell, the small frame is kept in place to ensure installation accuracy: the load of the small frame is transferred to the large frame on the furnace top through the high rigidity small frame support system, and the small frame is completely separated from the furnace shell. There is no need to remove the small frame during the furnace shell replacement process; after resetting, the position deviation of the small frame is small, which ensures the positioning accuracy of the core process equipment of the blast furnace and avoids the impact on ironmaking production.

[0012] (2) Shorten the construction period and improve production efficiency: When replacing the furnace shell, the process of dismantling, reassembling and repeatedly calibrating the small frame is eliminated, which greatly shortens the overall construction period of the blast furnace renovation, reduces the downtime of ironmaking production, and helps to improve the production efficiency of the enterprise.

[0013] (3) Reduced construction costs: Reduced labor and equipment costs required for dismantling and reassembling small frames, while avoiding rework costs caused by precision deviations after reassembly, effectively reducing the total construction cost of blast furnace renovation.

[0014] (4) Stable structure and safe construction: The small frame support system is rigidly connected to the furnace top frame with steel profiles. The rigidity and stability of the overall structure are improved by setting steel beams, cross supports and T-shaped supports, which can prevent the small frame from shifting or collapsing during the furnace shell replacement construction, and ensure the quality and safety of the construction operation. Attached Figure Description

[0015] Figure 1 This is the front view of the small frame support system described in this invention.

[0016] Figure 2 yes Figure 1 Side view.

[0017] In the diagram: 1. Main frame of the furnace roof 2. Platform 3. Steel beam 4. Small frame 5. Connecting column 6. Cross brace 7. T-brace Detailed Implementation

[0018] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings: The present invention discloses a blast furnace maintenance construction method in which the small frame is kept in situ during furnace shell replacement, comprising the following steps: (1) Removal of equipment from the small frame: All equipment supported on the small frame is removed, that is, the additional load on the small frame is removed, leaving only the main body of the small frame; the main body of the small frame includes multiple columns and multiple crossbeams connecting the columns. (2) Establish a new small framework support system: like Figure 1 , Figure 2As shown, the furnace top frame 1 is modified. The furnace top frame 1 consists of frame columns and platform 2. The small frame 4 is located inside the furnace top frame 1. The platform 2 is located above the small frame 4. The platform 2 consists of platform beams and platform plates. Two parallel steel beams 3 are added to the bottom of the platform 2 directly above the small frame 4. The two ends of the steel beams 3 are connected to the platform beams respectively. A connecting column 5 is set at the top of the small frame 4 and above each column of the small frame 4. The top of the connecting column 5 is fixed to the bottom of the steel beam 3, and the bottom of the connecting column 5 is fixed to the top of the column of the small frame 4. Cross supports 6 are installed between each connecting column 5; T-shaped supports 7 are installed on the outside of the connecting columns on both sides. The T-shaped supports 7 are composed of long diagonal supports and short diagonal supports. The lower end of the long diagonal support is connected to the bottom of the corresponding column, and the upper end of the long diagonal support is connected to the platform beam; the upper end of the short diagonal support is connected to the steel beam 3, and the lower end of the short diagonal support is connected to the middle of the long diagonal support. (5) Separation of the small frame from the furnace shell: Remove the connection between the small frame and the furnace shell to completely separate the small frame from the furnace shell. The separated small frame is then supported by the large frame on the furnace top. (6) Remove the old furnace shell: The old furnace shell at the top of the blast furnace was dismantled in sections. After the old furnace shell was dismantled, the horizontal position, elevation and verticality of the small frame were re-measured to ensure that the deviation between each index and the initial design value was ≤3mm. (5) New furnace shell and connection to the small frame; Install the new furnace shell according to the design requirements. After the new furnace shell is installed and adjusted in place, reconnect and fix the small frame to the new furnace shell.

[0019] In step (1), the equipment carried on the small frame includes a bellless gearbox, a fabric chute and its tilting and rotating mechanism, a material flow regulating valve, an upper sealing valve / lower sealing valve, and a receiving tank.

[0020] In step (2), the steel beams and connecting columns are made of H-beams, and the cross supports and T-supports are made of angle steel.

[0021] In step (2), the small frame is a rectangular frame structure with 4 columns, and correspondingly, 4 connecting columns are also provided; the cross support is located between 2 connecting columns on the same side with a small spacing, and the plane of the T-shaped support is perpendicular to the plane of the cross support.

[0022] In step (2), when there is no platform beam at the upper end of the long inclined support, a support beam is added on the platform, and the two ends of the support beam are connected to the platform beam respectively, and the upper end of the long inclined support is connected to the support beam.

[0023] The small frame is connected to the furnace shell by high-strength bolts.

[0024] The principle of the blast furnace maintenance construction method described in this invention, which involves maintaining the small frame in situ during furnace shell replacement, is as follows: a small frame support system is used to connect the small frame to the platform above it (part of the large furnace top frame), and cross supports and T-shaped supports are added to reinforce the connection structure. Ultimately, the function of bearing the weight of the small frame is transferred entirely from the furnace shell to the large furnace top frame (transmitted downwards to the foundation).

[0025] The present invention describes a blast furnace maintenance construction method that maintains the small frame in situ during furnace shell replacement. The construction process is simple and easy to operate. First, all equipment supporting the upper part of the small frame is removed. Then, the furnace top frame is modified (mainly involving the platform). Then, the small frame support system is constructed. After cutting off the connection between the small frame and the furnace shell (such as the high-strength bolts between the column base and the furnace shell), the furnace shell is replaced. After the furnace shell is replaced, it can be reconnected to the small frame.

[0026] To more intuitively illustrate the present invention, the embodiments of the present invention will be further described in conjunction with the examples. The following examples are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any technical solutions that can be obviously obtained by those skilled in the art within the scope of the technology disclosed in the present invention, including simple variations or equivalent substitutions, are all within the scope of protection of the present invention.

[0027]

Example

[0028] 2. The establishment of a small-frame support system (such as...) Figure 1 , Figure 2 (as shown) (1) Modification of the platform inside the furnace top frame: The platform 2 (a component of the furnace top frame 1) with an elevation of 54.3m above the small frame 4 is reinforced. Two parallel steel beams 3 are added above the four columns of the corresponding small frame 4. The steel beams 3 are made of HN700×300×13×24 H-beams (HN represents narrow flange steel, 700 represents the section height of 700mm, 300 represents the flange width of 300mm, 13 represents the web thickness of 13mm, and 24 represents the flange thickness of 24mm) to form a rigid load-bearing base.

[0029] (2) Rigid connection between columns and platform: Connecting columns 5 are used to connect each column of the small frame 4 to the steel beam 3. The connecting beam 5 is made of HW300×300×10×15 H-beam (HN300 represents narrow flange H-beam with a section height of 300mm; the 300 represents the flange width of 300mm, 10 represents the web thickness of 10mm, and 15 represents the flange thickness of 15mm), to achieve the initial constraint of the small frame 4 in the vertical and horizontal directions.

[0030] (3) Support System Installation: To ensure that the small frame 4 remains fixed in the horizontal direction, a cross support 6 is installed between two sets of closely spaced connecting columns 5. The cross support 6 is made of equilateral angle steel of model L100×8 (L represents angle steel, 100 represents the side width of the angle steel is 100mm, and 8 represents the thickness of the angle steel is 8mm). T-shaped supports 7 are then installed on the outside of the two connecting columns 5 with cross supports 6, also made of L100×8 angle steel. The upper end of the T-shaped support is fixedly connected to the platform beam at an elevation of 54.3m. If there is no platform beam for connection, a support beam is added; a comprehensive, high-rigidity in-situ constraint system is constructed through the support system.

[0031] 3. The small frame is separated from the old furnace shell; After the rigidly constrained small frame support system is erected and passes inspection, the high-strength bolts between the column bases of the small frame and the old furnace shell are removed, severing the stress connection between the small frame and the old furnace shell. The load of the small frame is then completely transferred to the large frame at the top of the furnace through the small frame support system, achieving unconstrained column base area.

[0032] 4. Before resetting, re-measure the positional accuracy of the small frame; The old furnace shell at the top of the blast furnace was dismantled in sections. After the old furnace shell was dismantled, the horizontal position, elevation, and verticality of the small frame were re-measured to ensure that the deviation of each position of the small frame was ≤3mm, which met the design and blast furnace process installation accuracy requirements.

[0033] 5. Installation of the new furnace shell and repositioning of the small frame; Install the new furnace shell according to the design requirements. After the new furnace shell is installed in place and adjusted to meet the requirements, reconnect and fix the column feet of the small frame to the new furnace shell with high-strength bolts. With this, the blast furnace repair work involving the replacement of the furnace shell is complete.

[0034] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for blast furnace maintenance where the small frame is kept in situ during furnace shell replacement, characterized in that... Includes the following steps: (1) Removal of equipment from the small frame: All equipment supported on the small frame is removed, that is, the additional load on the small frame is removed, leaving only the main body of the small frame; the main body of the small frame includes multiple columns and multiple crossbeams connecting the columns. (2) Establish a new small framework support system: The furnace top frame is modified. The furnace top frame consists of frame columns and a platform. The small frame is located inside the furnace top frame. A platform is set on top of the small frame. The platform consists of platform beams and platform slabs. Two parallel steel beams are added at the bottom of the platform directly above the small frame. The two ends of the steel beams are connected to the platform beams respectively. A connecting column is installed at the top of the small frame and above each column of the small frame. The top of the connecting column is fixed to the bottom of the steel beam, and the bottom of the connecting column is fixed to the top of the column of the small frame. Cross supports are installed between each connecting column; T-shaped supports are installed on the outer side of the connecting columns on both sides. The T-shaped supports consist of long diagonal supports and short diagonal supports. The lower end of the long diagonal support is connected to the bottom of the corresponding column, and the upper end of the long diagonal support is connected to the platform beam; the upper end of the short diagonal support is connected to the steel beam, and the lower end of the short diagonal support is connected to the middle of the long diagonal support. (3) Separation of the small frame from the furnace shell: Remove the connection between the small frame and the furnace shell to completely separate the small frame from the furnace shell. The separated small frame is then supported by the large frame on the furnace top. (4) Remove the old furnace shell: The old furnace shell at the top of the blast furnace was dismantled in sections. After the old furnace shell was dismantled, the horizontal position, elevation and verticality of the small frame were re-measured to ensure that the deviation between each index and the initial design value was ≤3mm. (5) New furnace shell and connection to the small frame; Install the new furnace shell according to the design requirements. After the new furnace shell is installed and adjusted in place, reconnect and fix the small frame to the new furnace shell.

2. The blast furnace maintenance construction method according to claim 1, which involves maintaining the small frame in situ during furnace shell replacement, is characterized in that... In step (1), the equipment carried on the small frame includes a bellless gearbox, a cloth chute and its tilting and rotating mechanism, a material flow regulating valve, an upper sealing valve, a lower sealing valve, and a receiving tank.

3. The blast furnace maintenance construction method according to claim 1, which involves maintaining the small frame in situ during furnace shell replacement, is characterized in that... In step (2), the steel beams and connecting columns are made of H-beams, and the cross supports and T-supports are made of angle steel.

4. A blast furnace maintenance construction method according to claim 1, wherein the small frame is kept in situ during furnace shell replacement, characterized in that, In step (2), the small frame is a rectangular frame structure with 4 columns, and correspondingly, 4 connecting columns are also provided; the cross support is located between 2 connecting columns on the same side with a small spacing, and the plane of the T-shaped support is perpendicular to the plane of the cross support.

5. A blast furnace maintenance construction method according to claim 1, wherein the small frame is kept in situ during furnace shell replacement, characterized in that, In step (2), when there is no platform beam at the upper end of the long inclined support, a support beam is added on the platform, and the two ends of the support beam are connected to the platform beam respectively, and the upper end of the long inclined support is connected to the support beam.

6. A blast furnace maintenance construction method according to claim 1, wherein the small frame is kept in situ during furnace shell replacement, characterized in that, The small frame is connected to the furnace shell by high-strength bolts.

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