Protection method for air bellow of sintering machine

Abstract

The invention relates to the technical field of metallurgical equipment, in particular to a protection method for a sintering machine air bellow, which is characterized in that a protection structure is arranged in the sintering machine air bellow, so that high-temperature and high-speed airflow is prevented from directly contacting with the sintering machine air bellow in use, abrasion of the sintering machine air bellow can be effectively reduced, and oxidation corrosion of metal is reduced. Through high-temperature ventilation simulation of the bellows protection three-dimensional model, a thermal stress concentration area and a deformation area are confirmed according to first thermal stress data and first deformation data of the sintering machine bellows in operation, and thermal stress is released by arranging stress holes, so that deformation or cracking of the protection structure at high temperature is avoided, and the service life of the sintering machine bellows is prolonged. And meanwhile, the bolts can fix the protection structure in the sintering machine air bellow through the stress holes, so that the protection structure is convenient to disassemble and replace, and the occurrence rate of fixing failure accidents at high temperature can be reduced.

Description

Technical Field

[0001] The invention relates to the technical field of metallurgical equipment, in particular to a protection method for a sintering machine bellows. Background Art

[0002] Sintering machines are important metallurgical equipment widely used in the steel industry. They are used to sinter raw materials such as iron ore powder at high temperatures into sintered ore with a certain mechanical strength and particle size. The stable operation of sintering machines is crucial to improving production efficiency and product quality. The sintering machine bellows is a key component in the sintering process. Its main function is to ensure sufficient fuel combustion and maintain stable and efficient operation of the sintering process by uniformly supplying air, controlling negative pressure, and exhaust gas emissions. Sintering machine bellows are usually made of steel plates or other metal materials, and have a complex internal structure, including multiple ventilation ducts and air distribution devices.

[0003] During the sintering process, due to the combined effects of high temperature, high-speed airflow, and abrasive materials, the bellows body is susceptible to severe wear, resulting in a shortened equipment life and increased maintenance costs. Specific problems include: (1) The interior of the bellows is exposed to a high-temperature environment for a long time, causing oxidation and corrosion on the metal surface. (2) Particles carried by the high-speed airflow impact and rub against the inner wall of the bellows, accelerating wear. (3) Long-term thermal cycling and mechanical stress cause fatigue cracks in the bellows structure. (4) Frequent wear and corrosion require frequent inspection or replacement of bellows components, increasing maintenance difficulty and downtime.

[0004] At present, in order to solve the wear problem of the bellows body, commonly used protective measures include surface coating, lining ceramic tiles and body welded steel plates. However, these methods have some limitations in practical applications: the coating material of the surface coating is easy to peel off in a high temperature environment, and the coating thickness is limited, and it cannot provide long-term and effective protection. Although the lining ceramic tiles have good wear resistance, the installation of ceramic tiles is complicated and costly, and they are prone to cracking in a high temperature environment. The welding of the body welded steel plate is difficult and takes a long time. In a high temperature environment, the weld is prone to cracking due to uneven heating, causing the steel plate to fall off, thereby causing the bellows to be perforated again, which has a great impact on the output of the sintering machine. Summary of the Invention

[0005] The main purpose of the present invention is to provide a protection method for a sintering machine bellows to solve the technical problem that the interior of the bellows is in a high-temperature environment for a long time, resulting in surface oxidation corrosion and easy wear of the inner wall of the bellows.

[0006] To achieve the above object, the present invention provides a method for protecting a sintering machine wind box, comprising the following steps:

[0007] S1. Obtaining a first shape and a first size of the interior of a sintering machine wind box, and manufacturing a protective structure according to the first shape and the first size;

[0008] S2. Acquire a second shape and a second size of the protective structure, and establish a three-dimensional model of the bellows protection according to the first shape, the first size, the second shape, and the second size;

[0009] S3. Simulating the three-dimensional model of the bellows protection, and obtaining first thermal stress data and first deformation data of the three-dimensional model of the bellows protection under preset working conditions;

[0010] S4. Determine a thermal stress concentration area of ​​the bellows protection three-dimensional model according to the first thermal stress data, and determine a deformation area of ​​the bellows protection three-dimensional model according to the first deformation data;

[0011] S5. Opening stress holes on the protective structure; wherein the areas where the stress holes are opened on the protective structure correspond to the thermal stress concentration areas and deformation areas of the three-dimensional model of the bellows protection;

[0012] S6. Pass the bolts through the stress holes to fix the protective structure to the inner wall of the sintering machine bellows to protect the sintering machine bellows.

[0013] Furthermore, the step S3 specifically includes the following steps:

[0014] S31. Inputting material properties of the three-dimensional model of the bellows protection into finite element analysis software, and dividing the surface of the protection structure into a grid model;

[0015] S32, setting the simulated temperature and negative pressure and the boundary constraints of the protective structure in the bellows protection three-dimensional model;

[0016] S33. Simulate the three-dimensional model of the bellows protection, perform finite element analysis on the simulation process, and obtain first thermal stress data and first deformation data of the three-dimensional model of the bellows protection.

[0017] Furthermore, the following steps are further included between steps S4 and S5:

[0018] S41, setting simulation holes on the protective structure model within the bellows protection three-dimensional model according to the first thermal stress data and the first deformation data to form a new bellows protection three-dimensional model, wherein the simulation holes are evenly distributed in the thermal stress concentration area and the deformation area;

[0019] S42, simulating the new bellows protection three-dimensional model to obtain second thermal stress data and second deformation data;

[0020] S43, determining whether a thermal stress concentration area and a deformation area still exist in the second thermal stress data and the second deformation data;

[0021] S44, if it is determined that the thermal stress concentration area and the deformation area still exist, then increase the density of the simulated holes in the thermal stress concentration area and / or the deformation area, and then return to step S42;

[0022] S45: If it is determined that there is no thermal stress concentration area and deformation area, proceed to step S5.

[0023] Furthermore, in step S5, in the stress hole region corresponding to the thermal stress concentration region, the stress holes are evenly distributed in the stress hole region; and in the stress hole region corresponding to the deformation region, the distribution density of the stress holes is increased.

[0024] Further preferably, the stress holes are arranged in a plum blossom shape as distribution units.

[0025] Furthermore, in step S6, before the protective structure is fixed to the inner wall of the sintering machine wind box, dust, lumps and rust inside the sintering machine wind box are cleaned.

[0026] Further preferably, the protection structure is formed by splicing a plurality of protection plates, and the protection plates are tightly fixed to the inner wall of the sintering machine wind box.

[0027] Further preferably, the protective plate is a high-temperature-resistant and wear-resistant metal plate, and the side edges of the protective plate are provided with inclined surfaces so that adjacent protective plates can be fully joined.

[0028] Preferably, threaded holes are opened on the inner wall of the sintering machine bellows, and the threaded holes correspond to the stress holes one by one; bolts pass through the stress holes and the threaded holes, so that the protective structure is fixed to the inner wall of the sintering machine bellows, completing the installation of the protective structure; wherein, the threaded hole is a semi-through hole, and a gasket is provided between the screw head of the bolt and the stress hole.

[0029] Preferably, the bolt is a fully threaded bolt without a screw head, one end of the bolt is welded to the inner wall of the sintering machine bellows, the position of the bolt corresponds to the position of the stress hole one-to-one, the other end of the bolt passes through the stress hole and is connected to the nut, a gasket is provided between the nut and the stress hole, so that the protective structure is fixed to the inner wall of the sintering machine bellows, completing the installation of the protective structure.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The present invention provides a protective structure within the sintering machine bellows to prevent direct contact between the high-temperature, high-speed airflow and the sintering machine bellows during use, effectively reducing wear and tear on the sintering machine bellows and reducing metal oxidative corrosion. High-temperature ventilation simulation of the bellows protection three-dimensional model is performed, and the first thermal stress and deformation data of the sintering machine bellows during operation are used to identify areas of concentrated thermal stress and deformation. Stress holes are provided to release thermal stress, thereby preventing deformation or cracking of the protective structure at high temperatures. Bolts can also secure the protective structure to the sintering machine bellows via the stress holes, facilitating removal and replacement of the protective structure while also reducing the incidence of fastening failures at high temperatures. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0033] Figure 1 1. A schematic flow chart of a method for protecting a sintering machine wind box in one embodiment of the present invention;

[0034] Figure 2 Schematic top view of the internal structure of a sintering machine wind box in one embodiment of the present invention;

[0035] Figure 3 1 is a side view of a sintering machine wind box in one embodiment of the present invention;

[0036] Figure 4 FIG. 4 is a schematic diagram of stress hole distribution of a first protective plate in an embodiment of the present invention.

[0037] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments.

[0038] Description of Figure Numbers:

[0039] 1. First protective plate; 2. Second protective plate; 3. Third protective plate; 4. Fourth protective plate; 5. Bolt; 6. Gasket; 7. Nut; 8. Stress hole. DETAILED DESCRIPTION

[0040] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0041] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0042] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as described in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0043] In addition, the descriptions of "first", "second", etc. in the present invention are for descriptive purposes only and should not be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0044] The sintering machine bellows used in this embodiment is a common conical bellows, such as Figures 2 to 4 The sintering machine wind box protection method adopted in this embodiment is generally based on an existing sintering machine and is implemented during the one-day shutdown period for quarterly maintenance of the sintering machine, thereby avoiding affecting production efficiency.

[0045] See also Figure 1 This embodiment provides a method for protecting a sintering machine wind box, comprising the following steps:

[0046] S1. Obtain a first shape and first size of the interior of the sintering machine bellows, and fabricate a protective structure based on the first shape and first size. In this embodiment, the protective structure is divided into four protective plates. Four trapezoidal protective plates are fabricated based on the first shape and first size of the interior of the sintering machine bellows. The protective plates are made of high-temperature and wear-resistant metal plates, preferably cost-effective steel plates. Bevels are provided on the sides of the protective plates to allow adjacent protective plates to fully engage. The protective plates are tightly fixed to the inner wall of the sintering machine bellows, ensuring that the protective plates fit tightly during splicing to prevent high-temperature airflow from entering through the splicing gap and contacting the sintering machine bellows.

[0047] Specifically, the thickness of the protective plate in this embodiment is 10-12 mm, and the protective plate includes a first protective plate 1, a second protective plate 2, a third protective plate 3 and a fourth protective plate 4. The dimensions of the first protective plate 1 and the third protective plate 3 are isosceles trapezoids with an upper width of 2.6 m, a lower width of 1.4 m, and a height of 1.5 m. The dimensions of the second protective plate 2 and the fourth protective plate 4 are isosceles trapezoids with an upper width of 1.3 m, a lower width of 0.7 m, and a height of 1.5 m.

[0048] S2. Obtain the second shape and second size of the protective structure, and establish a three-dimensional model of the bellows protection in finite element analysis software based on the first shape, the first size, the second shape and the second size; to facilitate understanding by those skilled in the art, the finite element analysis software used in this embodiment is ANSYS, and the three-dimensional model of the bellows protection is created in ANSYS Workbench.

[0049] S3. Perform high-temperature ventilation simulation on the three-dimensional model of the bellows protection using finite element analysis software, perform finite element analysis on the process of the high-temperature ventilation simulation, and obtain first thermal stress data and first deformation data of the three-dimensional model of the bellows protection under preset working conditions.

[0050] S4. Determine a thermal stress concentration area and a deformation area of ​​the bellows protection three-dimensional model according to the first thermal stress data and the first deformation data.

[0051] S5. Stress holes 8 are opened on the protective structure; wherein the areas where the stress holes 8 of the protective structure are opened correspond to the thermal stress concentration areas and deformation areas of the three-dimensional model of the bellows protection; further preferably, the stress holes 8 are arranged in a plum blossom shape as distribution units, such as Figure 4 As shown in Figure 1, the plum blossom-shaped distribution of stress holes 8 evenly disperses thermal stress during heating, reducing stress concentration. The symmetry of the plum blossom-shaped distribution facilitates coordination of deformation in different directions, reducing structural distortion. The plum blossom-shaped distribution also avoids the formation of a continuous weak line in a single direction (such as the "weak axis" that can occur with a square distribution), thereby maintaining the mechanical properties of the protective plate in multiple directions.

[0052] S6. Bolts 5 are set to pass through the stress holes 8 so that the protective structure is fixed to the inner wall of the sintering machine bellows, completing the installation of the protective structure. The welding fixing method may crack or even explode in an environment with frequent temperature changes, resulting in fixation failure. The gluing fixing method is also prone to fixation failure in a high-temperature environment because it is not resistant to high temperatures. The snap-on fixing method generally has a large gap. In the sintering machine, a large amount of dust and other debris will remain in the gap, making it inconvenient to disassemble and assemble the protective plate, and the airflow can easily pass through the gap and contact the sintering machine bellows, causing wear of the sintering machine bellows. In this embodiment, the stress hole 8 is used to set the bolt 5, which not only does not require an additional fixing structure, but also has a lower probability of failure in a high-temperature environment.

[0053] This embodiment provides a protective structure within the sintering machine bellows to prevent direct contact between the high-temperature, high-speed airflow and the sintering machine bellows during operation, effectively reducing wear and tear on the sintering machine bellows and reducing metal oxidative corrosion. High-temperature ventilation simulation of the bellows protection three-dimensional model is performed, and the first thermal stress and deformation data of the sintering machine bellows during operation are used to identify areas of concentrated thermal stress and deformation. Stress holes 8 are provided to release thermal stress, thereby preventing deformation or cracking of the protective structure at high temperatures. Bolts 5, meanwhile, secure the protective structure to the sintering machine bellows via the stress holes 8. This not only facilitates removal and replacement of the protective structure but also reduces the incidence of fastening failures at high temperatures.

[0054] In this embodiment, step S3 specifically includes the following steps:

[0055] S31. Input the material properties of the three-dimensional model of the bellows protection and divide the surface of the protection structure into a mesh model. In this embodiment, the material properties of the steel plate are input into the Engineering Data module of ANSYS, and the protection plate model is divided into a mesh in the Mesh module. The mesh density can also be increased in local locations where thermal stress concentration is expected.

[0056] S32. Set the temperature and negative pressure for the high-temperature ventilation simulation in the Thermal module. The negative pressure is set to 17.5 kPa. The three-dimensional bellows protection model includes models of the protective plate and the sintering machine bellows. The protective plate is installed inside the sintering machine bellows. Set the boundary constraints between the protective plate and the sintering machine bellows in the Structural module. The temperature in the high-temperature ventilation simulation can be set to a constant 450°C or a single temperature change process from 30°C to 500°C within 2 hours. This effectively simulates the temperature changes inside the sintering machine bellows during actual operation and improves the reliability of the simulation results.

[0057] S33: In the Solution module, perform a high-temperature ventilation simulation on the three-dimensional model of the bellows protection, perform finite element analysis on the high-temperature ventilation simulation process, and obtain first thermal stress data and first deformation data of the three-dimensional model of the bellows protection in the Results module. The first thermal stress data is a thermal stress distribution diagram, and the first deformation data is a deformation cloud diagram.

[0058] In this embodiment, as a further preferred embodiment, a verification process of whether the arrangement of the stress holes 8 is reasonable is further included between steps S4 and S5. The specific steps are as follows:

[0059] S41, setting simulation holes on the protective structure model within the bellows protection three-dimensional model according to the first thermal stress data and the first deformation data to form a new bellows protection three-dimensional model, wherein the simulation holes are evenly distributed in the thermal stress concentration area and the deformation area;

[0060] S42. Performing a high-temperature ventilation simulation on the new three-dimensional model of the wind box protection, performing a finite element analysis on the high-temperature ventilation simulation process, and obtaining second thermal stress data and second deformation data;

[0061] S43, determining whether a thermal stress concentration area and a deformation area still exist in the second thermal stress data and the second deformation data;

[0062] S44, if it is determined that the thermal stress concentration area and the deformation area still exist, then increase the density of the simulated holes in the thermal stress concentration area and / or the deformation area, and then return to step S42;

[0063] S45: If it is determined that there is no thermal stress concentration area and deformation area, proceed to step S5.

[0064] Furthermore, in this embodiment, in step S5 , the stress holes 8 are evenly distributed in the stress hole region corresponding to the thermal stress concentration region; and the distribution density of the stress holes 8 is increased in the stress hole region corresponding to the deformation region.

[0065] Specifically, in this embodiment, the number of stress holes 8 is set to 90, of which 30 are set on the first protective plate 1 and the third protective plate 3, and 15 are set on the second protective plate 2 and the fourth protective plate 4. The aperture of the stress hole 8 is 20 mm, and the stress holes 8 are evenly arranged in a plum blossom shape in the thermal stress concentration area. The center distance between adjacent holes is 240 mm. The edge of each stress hole 8 is chamfered with a chamfer radius of 1.5 mm, and the edge of the stress hole 8 is polished to improve the surface finish and reduce the risk of oxidation and corrosion at high temperature.

[0066] Furthermore, in step S6, before the protective structure is fixed to the inner wall of the sintering machine windbox, dust, lumps, and rust inside the sintering machine windbox are cleaned. This ensures that the protective plate is in close contact with the sintering machine windbox to prevent airflow from entering between the protective plate and the sintering machine, causing wear and dust accumulation.

[0067] In one embodiment, threaded holes are provided on the inner wall of the sintering machine bellows, corresponding one-to-one with the stress holes 8. Bolts 5 are passed through the stress holes 8 and the threaded holes, thereby securing the protective structure to the inner wall of the sintering machine bellows and completing the installation of the protective structure. The threaded holes are semi-through holes, and a gasket 6 is provided between the screw head of the bolt 5 and the stress hole 8. The gasket 6 not only improves the stability of the bolt 5 connection but also seals the stress hole 8 and the threaded hole, preventing airflow from entering the holes and causing dust accumulation.

[0068] Further preferably, the stress hole 8 in this embodiment is a countersunk hole, and the screw head of the bolt 5 is fixed in the countersunk hole to prevent the screw head from leaking out of the protective plate and causing the bolt 5 to wear.

[0069] In another embodiment, the bolt 5 is a fully threaded bolt without a screw head, one end of the bolt 5 is welded to the inner wall of the sintering machine bellows, the position of the bolt 5 corresponds one-to-one to the position of the stress hole 8, and the other end of the bolt 5 is connected to the nut 7 after passing through the stress hole 8. A gasket 6 is provided between the nut 7 and the stress hole 8, so that the protective structure is fixed to the inner wall of the sintering machine bellows, completing the installation of the protective structure.

[0070] The above are only preferred embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for protecting a sintering machine wind box, characterized in that: The steps include: S1. Obtaining a first shape and a first size of the interior of a sintering machine wind box, and manufacturing a protective structure according to the first shape and the first size; S2. Acquire a second shape and a second size of the protective structure, and establish a three-dimensional model of the bellows protection according to the first shape, the first size, the second shape, and the second size; S3. Simulating the three-dimensional model of the bellows protection, and obtaining first thermal stress data and first deformation data of the three-dimensional model of the bellows protection under preset working conditions; S4. Determine a thermal stress concentration area of ​​the bellows protection three-dimensional model according to the first thermal stress data, and determine a deformation area of ​​the bellows protection three-dimensional model according to the first deformation data; S5. Opening stress holes on the protective structure; wherein the areas where the stress holes are opened on the protective structure correspond to the thermal stress concentration areas and deformation areas of the three-dimensional model of the bellows protection; S6. Pass the bolts through the stress holes to fix the protective structure to the inner wall of the sintering machine bellows to protect the sintering machine bellows.

2. The protection method for a sintering machine wind box according to claim 1, characterized in that: The step S3 specifically includes the following steps: S31. Inputting material properties of the three-dimensional model of the bellows protection into finite element analysis software, and dividing the surface of the protection structure into a grid model; S32, setting the simulated temperature and negative pressure and the boundary constraints of the protective structure in the bellows protection three-dimensional model; S33. Simulate the three-dimensional model of the bellows protection, perform finite element analysis on the simulation process, and obtain first thermal stress data and first deformation data of the three-dimensional model of the bellows protection.

3. The method for protecting the sintering machine wind box according to claim 1, characterized in that: The following steps are also included between steps S4 and S5: S41, setting simulation holes on the protective structure model within the bellows protection three-dimensional model according to the first thermal stress data and the first deformation data to form a new bellows protection three-dimensional model, wherein the simulation holes are evenly distributed in the thermal stress concentration area and the deformation area; S42, simulating the new bellows protection three-dimensional model to obtain second thermal stress data and second deformation data; S43, determining whether a thermal stress concentration area and a deformation area still exist in the second thermal stress data and the second deformation data; S44, if it is determined that the thermal stress concentration area and the deformation area still exist, then increase the density of the simulated holes in the thermal stress concentration area and / or the deformation area, and then return to step S42; S45: If it is determined that there is no thermal stress concentration area and deformation area, proceed to step S5.

4. The method for protecting a sintering machine wind box according to claim 1, characterized in that: In step S5 , the stress holes are evenly distributed in the stress hole region corresponding to the thermal stress concentration region; and the distribution density of the stress holes is increased in the stress hole region corresponding to the deformation region.

5. The protection method for a sintering machine wind box according to claim 4, characterized in that: The stress holes are arranged in a plum blossom shape as a distribution unit.

6. The method for protecting a sintering machine wind box according to claim 1, characterized in that: In step S6, before the protective structure is fixed to the inner wall of the sintering machine wind box, dust, lumps and rust inside the sintering machine wind box are cleaned.

7. The method for protecting the sintering machine wind box according to claim 6, characterized in that: The protection structure is formed by splicing a plurality of protection plates, and the protection plates are tightly fixed to the inner wall of the sintering machine wind box.

8. The method for protecting the sintering machine wind box according to claim 7, characterized in that: The protective plates are high-temperature-resistant and wear-resistant metal plates, and inclined surfaces are provided on the sides of the protective plates so that adjacent protective plates can be fully joined.

9. The method for protecting a sintering machine wind box according to claim 1, characterized in that: A threaded hole is opened on the inner wall of the sintering machine bellows, and the threaded hole corresponds to the stress hole one by one; bolts pass through the stress hole and the threaded hole, so that the protective structure is fixed to the inner wall of the sintering machine bellows, completing the installation of the protective structure; wherein, the threaded hole is a semi-through hole, and a gasket is provided between the screw head of the bolt and the stress hole.

10. The protection method for a sintering machine wind box according to claim 1, characterized in that: The bolt is a fully threaded bolt without a screw head. One end of the bolt is welded to the inner wall of the sintering machine bellows. The position of the bolt corresponds to the position of the stress hole. The other end of the bolt passes through the stress hole and is connected to the nut. A gasket is provided between the nut and the stress hole, so that the protective structure is fixed to the inner wall of the sintering machine bellows, completing the installation of the protective structure.

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