Installation Method for Top Flange of Large Blast Furnace

Abstract

The present invention provides a method for installing the top flange of a large blast furnace, belonging to the technical field of equipment installation, and comprising the following steps: S1. Uniformly install a plurality of alignment devices on the circumference of the furnace shell. The alignment device includes a fixed seat and an adjustment block slidably arranged on the fixed seat, and the upper end surface of the adjustment block is a slope surface; S2. Hoist and place the top flange at the groove opening at the furnace throat of the blast furnace, and the lower end surface of the top flange is located above the adjustment block; S3. Adjust the alignment device, drive the adjustment block to move radially along the top flange, and adjust the inclination angle of the top flange; S4. Weld the top flange and the groove opening. The method for installing the top flange of a large blast furnace provided by the present invention adjusts the alignment of the top flange through the slope surface of the adjustment block, and realizes the longitudinal displacement of the top flange by lateral movement, which is convenient for the staff to operate, improves the alignment efficiency, shortens the alignment time of the top flange of the blast furnace, shortens the construction period for the installation of the top equipment of the blast furnace, and reduces the cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of equipment installation, and more specifically, relates to a method for installing a large blast furnace top flange. Background Art

[0002] As the core equipment of the blast furnace top charging system, the installation accuracy of the top flange has a very large impact on the burden distribution of the blast furnace. In order to control the installation accuracy of the blast furnace top flange, it is necessary to control it during the positioning and welding process of the top flange.

[0003] In existing metallurgical construction, when installing the blast furnace top flange, positioning and alignment are required. Currently, the commonly used alignment method is to weld baffles on the furnace shell and the flange, and then use jacks for adjustment, which is time-consuming and laborious, inconvenient to operate, has low efficiency, and affects the installation period of the top flange. Summary of the Invention

[0004] The purpose of the present invention is to provide a method for installing a large blast furnace top flange, aiming to improve the alignment efficiency of the top flange and save the construction period.

[0005] To achieve the above object, the technical solution adopted by the present invention is: to provide a method for installing a large blast furnace top flange, including the following steps:

[0006] S1. Uniformly install a plurality of alignment devices on the circumference of the furnace shell. The alignment device includes a fixed seat and an adjustment block slidably arranged on the fixed seat. The upper end surface of the adjustment block is a slope surface, and the upper end surface of the adjustment block is used to tightly press against the lower end of the top flange;

[0007] S2. Hoist and place the top flange at the groove at the blast furnace throat. The lower end surface of the top flange is located above the adjustment block;

[0008] S3. Adjust the alignment device, drive the adjustment block to move along the radial direction of the top flange, and adjust the inclination angle of the top flange;

[0009] S4. Weld the top flange and the groove.

[0010] As another embodiment of the present application, in step S1, the alignment device includes:

[0011] A jacking screw structure, which includes a fixing plate arranged at one end of the fixed seat away from the top flange and a jacking rod threadedly connected to the fixing plate. The free end of the jacking rod abuts against the adjustment block;

[0012] A slideway, which is opened on the upper end surface of the fixed seat along the radial direction of the top flange and is located on one side of the fixing plate. The slideway is matched with the lower end of the adjustment block.

[0013] As another embodiment of the present application, the cross-section of the adjusting block is a right triangle, where the plane where the first right-angled side is located is attached to the upper end surface of the fixed seat, the plane where the second right-angled side is located abuts against the ejector rod; the plane where the hypotenuse is located abuts against the lower end surface of the furnace top flange.

[0014] As another embodiment of the present application, the alignment device further includes:

[0015] A guiding frame, vertically arranged at the upper end of the fixed seat, the guiding frame is located on both sides of the adjusting block, the guiding frame includes two longitudinal support rods, and sliding rails are arranged on the opposite sides of the two support rods;

[0016] A support seat, slidably arranged on the guiding frame, both ends of the support seat are provided with support plates, and the support plates are slidably connected to the sliding rails; a guiding rod is arranged at the lower end of the support plate, and the guiding rod is a plurality of nested connecting sleeve rods; the lower end of the guiding rod is connected to the fixed seat, and an elastic member is sleeved outside the guiding rod.

[0017] As another embodiment of the present application, the lower end of the support seat is provided with an inclined surface parallel to the upper end surface of the adjusting block, and a roller is arranged at the lower end of the support seat, and the roller is attached to the upper end surface of the adjusting block.

[0018] As another embodiment of the present application, a spirit level is arranged on the upper end surface of the furnace top flange.

[0019] As another embodiment of the present application, in step S4, first perform alignment and then spot welding. After the spot welding is completed, repeat step S3 until the composite requirements are met and then perform full welding.

[0020] As another embodiment of the present application, in step S4, when welding, four welding points are set to weld simultaneously, and the welding is rotated in the same direction along the center line of the blast furnace.

[0021] As another embodiment of the present application, in step S4, when welding, the furnace head sealing plate and the lower flange of the steel ring need to be preheated, and the preheating temperature is maintained at 150 - 200 °C.

[0022] As another embodiment of the present application, in step S4, during the welding process, the alignment device and the spirit level are used multiple times to check the levelness of the furnace top flange steel ring.

[0023] The beneficial effects of the method for installing the furnace top flange of a large blast furnace provided by the present invention are as follows: Compared with the prior art, the method for installing the furnace top flange of a large blast furnace of the present invention adjusts the alignment of the furnace top flange through the slope of the adjusting block, and realizes the longitudinal displacement of the furnace top flange by lateral movement, which is convenient for the staff to operate, improves the alignment efficiency, shortens the alignment time of the furnace top flange of the blast furnace, shortens the construction period for the installation of the furnace top equipment of the blast furnace, and reduces the cost. Description of the Drawings

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0025] Figure 1 Schematic structural diagram of a large blast furnace provided by an embodiment of the present invention;

[0026] Figure 2 is Figure 1 enlarged view of part A in

[0027] Figure 3 Top view of a large blast furnace provided by an embodiment of the present invention.

[0028] In the figure: 1, furnace shell; 2, furnace top flange; 3, alignment device; 4, connecting rod; 5, fixed seat; 6, fixing plate; 7, ejector rod; 8, adjusting block; 9, support plate; 10, spring; 11, laser emitter; 12, laser receiver. Specific embodiments

[0029] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0030] Please refer to Figures 1 to 3 , and now the installation method of the furnace top flange 2 of the large blast furnace provided by the present invention will be described. The installation method of the furnace top flange 2 of the large blast furnace includes the following steps:

[0031] S1. Uniformly install a plurality of alignment devices 3 in the circumferential direction of the furnace shell 1. The alignment device 3 includes a fixed seat 5 and an adjusting block 8 slidably disposed on the fixed seat 5. The upper end surface of the adjusting block 8 is a slope surface, and the upper end surface of the adjusting block 8 is used to tightly abut against the lower end of the furnace top flange 2;

[0032] S2. Hoist and place the furnace top flange 2 at the groove opening at the furnace throat of the blast furnace. The lower end surface of the furnace top flange 2 is located above the adjusting block 8;

[0033] S3. Adjust the alignment device 3 to drive the adjusting block 8 to move radially along the furnace top flange 2 to adjust the inclination angle of the furnace top flange 2;

[0034] S4. Weld the furnace top flange 2 and the groove opening.

[0035] The installation method of the large blast furnace top flange 2 provided by the present invention, compared with the prior art, first installs a plurality of alignment devices 3 on the furnace shell 1. The alignment devices 3 facilitate aligning the top flange 2 after it is in place. After the alignment devices 3 are installed in place, the top flange 2 is hoisted and placed at the groove of the blast furnace throat. The lower end surface of the top flange 2 is located above the adjusting block 8. Adjust the alignment device 3 to drive the adjusting block 8 to move radially along the top flange 2 to align the top flange 2. Finally, weld the grooves of the top flange 2 and the furnace shell 1.

[0036] The alignment device 3 includes a fixed seat 5 welded on the furnace shell 1. The upper end of the fixed seat 5 is slidably connected with an adjusting block 8, and the upper end surface of the adjusting block 8 is set as a slope. When aligning, by driving the adjusting block 8 to move radially along the top flange 2, the up and down movement of the top flange 2 is driven through the slope.

[0037] The installation method of the large blast furnace top flange 2 provided by the present invention adjusts the alignment of the top flange 2 through the slope of the adjusting block 8, realizes the longitudinal displacement of the top flange 2 by lateral movement, is convenient for the staff to operate, improves the alignment efficiency, shortens the alignment time of the blast furnace top flange 2, shortens the construction period for the installation of the blast furnace top equipment, and reduces the cost.

[0038] The lower end of the fixed seat 5 is provided with a connecting rod 4, and the lower end of the connecting rod 4 is welded on the furnace shell 1.

[0039] In some possible embodiments, please refer to Figure 1 and Figure 2 In step S1, the alignment device 3 includes a jackscrew structure and a slideway. The jackscrew structure includes a fixing plate 6 provided at one end of the fixed seat 5 away from the top flange 2 and a jack rod 7 threadedly connected to the fixing plate 6. The free end of the jack rod 7 abuts against the adjusting block 8. The slideway is arranged on the upper end surface of the fixed seat 5 along the radial direction of the top flange 2 and is located on one side of the fixing plate 6. The slideway cooperates with the lower end of the adjusting block 8.

[0040] An adjusting block 8 is provided on one side of the fixed seat 5 close to the top flange 2, and a fixing plate 6 is provided on the side of the fixed seat 5 away from the top flange 2. The fixing plate 6 is located on one side of the adjusting block 8. A horizontal threaded hole is provided on the fixing plate 6 and a nut coaxial with the threaded hole is welded on one side of the fixing plate 6. The jack rod 7 penetrates through the threaded hole and the nut of the fixing plate 6 from the outside. One end of the jack rod 7 abuts against the rear end surface of the adjusting block 8, and the driving end of the jack rod 7 is located outside the fixing plate 6.

[0041] The upper end surface of the fixed seat 5 is provided with a slideway. The length direction of the slideway is the same as the radial direction of the top flange 2. The lower end of the adjusting block 8 cooperates with the slideway, and the adjusting block 8 slides away from or close to the top flange 2 along the length direction of the slideway.

[0042] In some possible embodiments, please refer to Figure 1 and Figure 2 , the cross-section of the adjusting block 8 is a right triangle, wherein the plane where the first right-angled side is located fits on the upper end surface of the fixed seat 5, the plane where the second right-angled side is located abuts against the ejector rod 7; the plane where the hypotenuse is located abuts against the lower end surface of the furnace top flange 2.

[0043] The thickness of the adjusting block 8 gradually increases from front to back. Here, the side close to the furnace top flange 2 is the front side, and the side where the fixing plate 6 is provided is the rear side. When the adjusting block 8 moves forward, the height of the furnace top flange 2 is raised; when the adjusting block 8 moves backward, the height of the furnace top flange 2 is lowered.

[0044] The cross-section of the adjusting block 8 is a right triangle, and the two right-angled sides of the adjusting block 8 are respectively located at the lower end and the rear end. The lower end surface of the adjusting block 8 fits on the upper end surface of the fixed seat 5, and the rear end surface of the adjusting block 8 abuts against the ejector rod 7. The slope surface where the hypotenuse of the adjusting block 8 is located abuts against the lower end surface of the furnace top flange 2.

[0045] Optionally, a level is provided on the upper end surface of the furnace top flange 2.

[0046] In some possible embodiments, please refer to Figure 1 and Figure 2 , the alignment device 3 further includes a guide frame, a support seat, a laser emitter 11 and a laser receiver 12. The guide frame is vertically arranged on the upper end of the fixed seat 5. The guide frame is located on both sides of the adjusting block 8. The guide frame includes two longitudinal support rods, and sliding rails are arranged on the opposite sides of the two support rods; the support seat is slidably arranged on the guide frame, and support plates 9 are arranged at both ends of the support seat. The support plates 9 are slidably connected with the sliding rails; a guide rod is arranged at the lower end of the support plate 9. The guide rod is a plurality of nested connecting sleeve rods; the lower end of the guide rod is connected to the fixed seat 5, and an elastic member is sleeved outside the guide rod; the laser emitter 11 is arranged on the upper end of the support seat, and the height of the laser emitter 11 is equal to the height of the top surface of the lower flange of the steel ring; the laser receiver 12 is arranged on the top surface of the lower flange of the steel ring. The laser receiver 12 corresponds to the laser emitter 11 one by one and is used to receive the signal emitted by the laser emitter 11.

[0047] The guide frame is located on both sides of the adjusting block 8. The guide frame includes two spaced support rods, and longitudinal sliding rails are arranged on the support rods. A support plate 9 is arranged between the two support rods. The two support plates 9 are arranged oppositely and the upper ends of the two support plates 9 are connected to the support seat, and a laser emitter 11 is arranged on the support seat.

[0048] A guide rod is further arranged at the lower end of the support plate 9. The guide rod is a plurality of nested sleeve rods for realizing its longitudinal expansion and contraction.

[0049] A spring 10 is sleeved outside the guide rod. In the state of not being stressed, the spring 10 drives the support seat to fit against the upper end surface of the adjustment block 8.

[0050] The laser emitter 11 and the laser receiver 12 conduct signal transmission. When the laser receiver 12 can receive the corresponding laser signal, the alignment work is completed.

[0051] Optionally, after the alignment and welding are completed, the laser receiver 12 can also be removed for easy reuse.

[0052] In some possible embodiments, the lower end of the support seat is provided with an inclined surface parallel to the upper end surface of the adjustment block 8, and a roller is provided at the lower end of the support seat. The roller fits against the upper end surface of the adjustment block 8.

[0053] The lower end surface of the support seat is a slope surface. The lower end surface of the support seat is parallel to the upper end surface of the adjustment block 8. When the adjustment block 8 moves forward, the adjustment block 8 drives the support seat to move upward, and the spring 10 is stretched. When the adjustment block 8 moves backward, the support seat contracts downward under the action of the spring 10 and fits against the upper end surface of the support seat.

[0054] A roller is installed at the lower end of the support seat. The roller fits against the upper end of the adjustment block 8, reducing the friction force between the support seat and the adjustment block 8 and reducing the error caused by friction.

[0055] In some possible embodiments, please refer to Figure 3 , at least eight laser emitters 11 are evenly arranged in the circumferential direction of the furnace shell 1.

[0056] Optionally, eight laser generators are provided on the furnace shell 1, and the eight laser emitters 11 are evenly distributed in a circle on the furnace shell 1; correspondingly, eight laser receivers 12 are provided on the top surface of the lower flange of the steel ring, and the eight laser receivers 12 are evenly distributed in a circle on the lower flange of the steel ring.

[0057] In some possible embodiments, in step S2, before installing the top steel ring of the furnace, it is necessary to ensure that all the opening welds of the furnace head hood part are welded, mainly including the gas outlet pipe, the chute replacement hole, the maintenance manhole, etc. This can prevent large welding deformation during the installation and welding of the top steel ring of the furnace.

[0058] The top steel ring of the furnace has been manufactured before leaving the factory. When installing, the upper surface of the furnace head hood should be leveled and polished smoothly. After placing the top steel ring on the furnace head hood, adjust the top steel ring.

[0059] There are 3 sealing grooves on the upper surface of the top steel ring of the furnace. When installing, the centers of the four bolt holes in the middle of the grooved hole should be placed at the quadrant points.

[0060] Attention: The installation shall not be misaligned. Once misaligned, the subsequent installation of the bell-less top equipment will also be misaligned, which will seriously affect the installation of the bunker and hopper. The top steel ring is a flat-bottom box type and is welded to the furnace head in a "butt joint". There are 8 equally distributed drain holes on the outer side of the steel ring. After installation, select two or four holes with appropriate orientations as drain holes and connect them to the drain pipes. The remaining drain holes and sewage holes shall be blocked with blind plates. For the levelness of the upper flange surface of the top steel ring, first use a level to evenly measure at least 10 points along the flange surface, and adjust the height difference between any two points on the upper flange surface to be controlled within 1 mm. Then use a cast iron straightedge in cooperation with a frame level (0.02 mm / m) for fine leveling.

[0061] In some possible embodiments, in step S4, first perform alignment and then spot welding. After spot welding is completed, repeat step S3 until the requirements are met and then perform full welding.

[0062] After adjustment and alignment, perform spot welding every 45 degrees. After spot welding is completed, measure the flatness deviation of the upper flange surface again. Welding can only be carried out if the requirements are met.

[0063] In step S4, when welding, set four welding points to weld simultaneously and rotate and weld in the same direction along the center line of the blast furnace. When welding, four welders perform welding simultaneously in the direction 90 degrees apart and rotate and weld in the same direction along the center line of the blast furnace.

[0064] When welding, the furnace head seal plate and the lower flange of the steel ring need to be preheated, and the preheating temperature is maintained at 150 - 200 °C until the welding is completed.

[0065] When performing external weld welding, first perform air gouging and root cleaning on the internal weld. The PT flaw detection (penetrant testing) method can be used to inspect the welding quality, and the unqualified parts must be repaired.

[0066] During the welding process, frequently use a straightedge and a level to check the levelness of the top steel ring and assume dial indicators at the four equal division points of the top steel ring to detect its installation reference.

[0067] In step S4, when welding, to improve the installation strength of the furnace shell 1 and the top flange 2 and reduce welding deformation, at the initial stage of welding, first weld a reinforcing plate on the outer side of the furnace shell 1. The reinforcing plate is located between two adjacent alignment devices 3. One side of the reinforcing plate is welded to the furnace shell 1, and the other side is welded to the lower end face of the top flange 2.

[0068] When welding, weld temporary braces inside the furnace shell 1. The temporary braces include a lower support located inside the furnace shell 1 and an upper brace located inside the top flange 2. The lower brace and the upper brace are arranged in parallel.

[0069] The allowable deviation requirements after the top steel ring welding is completed are as follows:

[0070] (1) The deviation between the center of the top steel ring and the center of the furnace body shall not be greater than 20 mm;

[0071] (2) The allowable error of the elevation of the upper flange surface of the top steel ring is ±10 mm; the flatness deviation of the upper flange surface of the top steel ring ≦ 2 mm (0.5 / 1000), that is, the difference between the maximum value and the minimum value measured shall not be greater than 2 mm;

[0072] (3) The flatness deviation within any 30-degree range of the upper flange surface of the top steel ring is ±0.25 mm.

[0073] (4) The flatness deviation within any 120-degree range of the upper flange surface of the top steel ring is ±0.35 mm.

[0074] After the top steel ring is welded, it needs to be inspected again. The inspection method includes the following steps:

[0075] Step 1: Detection of the coaxiality between the center of the upper flange of the top steel ring and the center of the furnace body: Use a wire-pulling method, hang a plumb bob and check with a steel ruler.

[0076] Step 2: Detection of the elevation of the upper flange surface of the top steel ring: Check with a level and a steel ruler.

[0077] Step 3: Detection of the flatness of the upper flange surface of the top steel ring: Check with a level or a straightedge and a spirit level.

[0078] The above is only the preferred embodiment of the present invention, and it is not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. Installation method for the top flange of a large blast furnace, characterized in that, It includes the following steps: S1. Uniformly install a plurality of alignment devices on the circumference of the furnace shell. The alignment device includes a fixed seat and an adjusting block slidably arranged on the fixed seat. The upper end surface of the adjusting block is a slope surface, and the upper end surface of the adjusting block is used to tightly abut against the lower end of the furnace top flange. S2. Hoist and place the furnace top flange on the groove at the blast furnace throat. The lower end surface of the furnace top flange is located above the adjusting block. S3. Adjust the alignment device, drive the adjusting block to move radially along the furnace top flange, and adjust the inclination angle of the furnace top flange. S4. Weld the furnace top flange and the groove. In step S1, the alignment device includes: A jackscrew structure. The jackscrew structure includes a fixing plate arranged at one end of the fixed seat away from the furnace top flange and a jackscrew threadedly connected to the fixing plate. The free end of the jackscrew abuts against the adjusting block. A slideway is opened on the upper end surface of the fixed seat along the radial direction of the furnace top flange and is located on one side of the fixing plate. The slideway is matched with the lower end of the adjusting block. The cross-section of the adjusting block is a right triangle. The plane where the first right-angle side is located fits on the upper end surface of the fixed seat, the plane where the second right-angle side is located abuts against the jackscrew, and the plane where the hypotenuse is located abuts against the lower end surface of the furnace top flange. The alignment device further includes: A guiding frame is vertically arranged on the upper end of the fixed seat. The guiding frame is located on both sides of the adjusting block. The guiding frame includes two longitudinal support rods, and sliding rails are arranged on the opposite sides of the two support rods. A support seat is slidably arranged on the guiding frame. Support plates are arranged at both ends of the support seat. The support plates are slidably connected with the sliding rails. A guiding rod is arranged at the lower end of the support plate. The guiding rod is a plurality of nested connecting sleeve rods. The lower end of the guiding rod is connected to the fixed seat, and an elastic member is sleeved outside the guiding rod. A laser emitter is arranged at the upper end of the support seat, and the height of the laser emitter is equal to the height of the top surface of the lower flange of the steel ring. A laser receiver is arranged on the top surface of the lower flange of the steel ring. The laser receivers correspond to the laser emitters one by one and are used to receive the signals emitted by the laser emitters. An inclined surface parallel to the upper end surface of the adjusting block is arranged at the lower end of the support seat, and rollers are arranged at the lower end of the support seat. The rollers are in contact with the upper end surface of the adjusting block.

2. The installation method of the large blast furnace top flange according to claim 1, characterized in that A spirit level is arranged on the upper end surface of the furnace top flange.

3. The installation method of the large blast furnace top flange according to claim 1, characterized in that, In step S4, first perform alignment and then spot welding. After the spot welding is completed, repeat step S3 until it meets the requirements and then perform full welding.

4. The installation method of the large blast furnace top flange according to claim 3, characterized in that In step S4, when welding, set four welding points to weld simultaneously and rotate and weld in the same direction along the center line of the blast furnace.

5. The installation method of the large blast furnace top flange according to claim 4, characterized in that In step S4, when welding, the furnace head sealing plate and the lower flange of the steel ring need to be preheated, and the preheating temperature is maintained at 150 - 200 °C.

6. The installation method of the large blast furnace top flange according to claim 5, characterized in that, In step S4, during the welding process, use the alignment device and the spirit level to check the levelness of the furnace top flange steel ring multiple times.

Images