Bottom blowing converter and metallurgy method

Abstract

The invention discloses a bottom-blown converter and a metallurgy method. The bottom-blown converter comprises a base, a converter body and a blowing assembly. The furnace body is arranged on the base, the furnace body comprises a bottom plate and a peripheral side plate arranged around the periphery of the bottom plate, and the peripheral side plate is connected with the bottom plate so as to define a molten pool cavity with the bottom plate; the upper surface of the bottom plate is provided with a plurality of blowing ports communicated with the molten pool cavity, and the peripheral side plate is provided with a discharge port communicated with the molten pool cavity; the gas blowing assembly is mounted on the base and used for blowing protective gas into the molten pool cavity through the gas blowing opening; the center of the upper surface of the bottom plate is a first center, the multiple air blowing openings are distributed around the first center at intervals, and the air blowing openings extend in the direction away from the first center in the radial direction of the bottom plate. The airflow blown out of the air blowing port is easier to disturb materials in the edge area of the molten pool cavity, so that the probability of a stirring dead zone can be reduced.

Description

Technical Field

[0001] This application relates to the field of metallurgical technology, and in particular to a bottom-blown converter and metallurgical method. Background Technology

[0002] A bottom-blown converter is a steelmaking device that enhances the stirring of the molten pool by blowing gas into the bottom of the furnace. During the smelting process, gas is blown from the bottom of the bottom-blown converter into the molten pool inside the converter. The gas flow uniformly stirs the molten steel in the pool, thereby bringing the reaction in the pool closer to equilibrium and improving the reaction efficiency and quality of the molten steel.

[0003] However, the inventors discovered that in existing bottom-blown converters, the airflow causes relatively gentle disturbance to the molten steel in the molten pool, resulting in poor stirring effect and the presence of stirring dead zones. Summary of the Invention

[0004] This application provides a bottom-blown converter and a metallurgical method, in which the airflow blown from the air outlet is more likely to disturb the material in the edge area of ​​the molten pool cavity, thereby reducing the probability of the occurrence of a stirring dead zone.

[0005] In a first aspect, this application provides a bottom-blown converter, comprising: Base; A furnace body is mounted on the base. The furnace body includes a bottom plate and peripheral side plates arranged around the outer periphery of the bottom plate. The peripheral side plates are connected to the bottom plate to form a molten pool cavity. A plurality of air blowing ports communicating with the molten pool cavity are provided on the upper surface of the bottom plate, and a discharge port communicating with the molten pool cavity is provided on the peripheral side plates. An air blowing assembly is mounted on the base, and the air blowing assembly is used to blow protective gas into the molten pool cavity through the air blowing port; The center of the upper surface of the base plate is the first center, and the plurality of air inlets are arranged at intervals around the first center, and the air inlets extend radially away from the first center along the base plate.

[0006] In some embodiments, the radius of the base plate is R, and the distance between the air inlet and the first center is r, where 0.4R ≤ r ≤ 0.6R.

[0007] In some embodiments, the length of the air inlet along the radial direction of the base plate is L, and the width of the air inlet along the circumferential direction of the base plate is d, where 10d≤L.

[0008] In some embodiments, the plurality of air outlets are rotationally symmetrical about the first center.

[0009] In some embodiments, the base plate is rotatably connected to the base and the peripheral side plate. The bottom-blown converter further includes a driving component, which is mounted on the base and is pulsatorically connected to the base plate. The driving component is used to drive the base plate to rotate around a first axis, which passes through the first center.

[0010] In some embodiments, the blowing assembly includes: An air blowing component is installed at the bottom of the base, and the air blowing component has an air outlet; A first pipe is disposed within the base and is rotatably connected to the base about a first axis; The second pipe is disposed inside the base plate. The second pipe is fixedly connected to the first pipe and communicates with the first pipe and the air outlet. The air outlet is connected to the air outlet through the first pipe and the second pipe. The driving component is connected to the first pipe and is used to drive the first pipe to rotate around the first axis, thereby driving the base plate and the second pipe to rotate around the first axis.

[0011] In some embodiments, the peripheral side plate includes a heating layer and a heat-insulating shell, the heating layer being disposed around the outer periphery of the base plate, the heating layer being used to heat the material in the molten pool cavity, and the heat-insulating shell being disposed around the outer periphery of the heating layer; A sealing structure is provided between the heat insulation shell and the base, and the sealing structure is arranged around the outer periphery of the heating layer and around the outer periphery of the base plate.

[0012] In some embodiments, the sealing structure includes multiple sealing layers, which are stacked sequentially along the radial direction of the base plate, and each of the multiple sealing layers is formed of a different material.

[0013] Secondly, this application also provides a metallurgical method applied to a bottom-blown converter, the metallurgical method comprising: The material is fed into the molten pool cavity and heated to melt it. When the material melts to a preset condition, the air blowing assembly is activated, and the air blowing assembly blows the protective gas into the molten pool cavity through the air blowing port. The flow rate of the protective gas is adjusted according to the duration of the protective gas venting. After the material is melted, the blowing assembly is turned off, and the molten material is discharged through the discharge port.

[0014] In some embodiments, the ventilation time of the protective gas is t, and the flow rate of the protective gas is Q. In the step of adjusting the flow rate of the protective gas according to the ventilation time, Q and t satisfy: The Q varies with t according to a sinusoidal function; or... The Q varies with t according to a cosine function; or... The Q increases linearly with t; or, The Q increases with t in a stepwise manner; or... Q varies randomly with t.

[0015] The beneficial effects of this application are as follows: On the one hand, by setting the air blowing port outside the first center and extending the air blowing port away from the first center, the distance between the air blowing port and the edge of the bottom plate can be shortened, making it easier for the airflow blown from the air blowing port to disturb the material in the edge area of ​​the molten pool cavity, thereby reducing the probability of the occurrence of a stirring dead zone; on the other hand, by setting multiple air blowing ports and arranging them at intervals around the first center, protective gas can be sprayed from multiple positions, thereby forming multiple airflows at various positions, which can enhance the disturbance formed by the protective gas in the molten material, making the disturbance formed by the airflow more intense, thereby improving the stirring effect on the material, and can form disturbances in more areas and directions of the material, reducing the probability of the occurrence of a stirring dead zone, thereby further improving the reaction efficiency and quality of smelting. Attached Figure Description

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

[0017] Figure 1 This is a schematic diagram of the bottom-blown converter according to an embodiment of this application from a first-view perspective; Figure 2 This is a schematic diagram of the bottom-blown converter according to an embodiment of this application from a second perspective. Figure 3 This is a schematic diagram of a portion of the structure of a bottom-blown converter according to an embodiment of this application, viewed from a third-person perspective. Figure 4 This is a schematic diagram of a portion of the structure of a bottom-blown converter according to an embodiment of this application from a fourth-angle perspective; Figure 5 This is a schematic diagram of a metallurgical process according to an embodiment of this application; Figure 6This is a simulation diagram illustrating how Q changes with t according to a sinusoidal function in one embodiment of this application; Figure 7 This is a simulation diagram illustrating how Q changes with t according to a cosine function in one embodiment of this application; Figure 8 This is a simulation diagram illustrating how Q increases linearly with t in one embodiment of this application; Figure 9 This is a simulation diagram showing how Q increases with t in a stepwise manner in one embodiment of this application; Figure 10 This is a simulation diagram showing the random variation of Q with t in one embodiment of this application.

[0018] Figure label: 10. Bottom-blown converter; 20. Base; 30. Furnace body; 31. Bottom plate; 311. Air inlet; 32. Side plate; 321. Heating layer; 322. Insulating shell; 33. Molten pool cavity; 40. Air blowing assembly; 41. Air blowing component; 411. Air outlet; 42. First pipe; 43. Second pipe; 50. Sealing structure; 51. Sealing layer; P, first center; K, first axis; R, radius of the base plate; r, distance between the air inlet and the first center; L, radial length of the air inlet along the base plate; d, circumferential width of the air inlet along the base plate. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0020] This application provides a bottom-blown converter and a metallurgical method to solve the problem that in existing bottom-blown converters, the airflow causes relatively gentle disturbance to the molten steel in the molten pool, resulting in poor stirring effect and the presence of stirring dead zones.

[0021] Firstly, this application provides a bottom-blown converter 10, such as Figures 1 to 3 As shown, the bottom-blown converter 10 includes a base 20, a furnace body 30, and an air blowing assembly 40.

[0022] The base 20 is used to place it on the ground or other locations. The base 20 provides an installation position and support for the furnace body 30 and the air blowing assembly 40. The base 20 may have multiple legs.

[0023] The furnace body 30 is mounted on the base 20. The furnace body 30 includes a bottom plate 31 and a peripheral side plate 32 arranged around the outer periphery of the bottom plate 31. The peripheral side plate 32 is connected to the bottom plate 31 to form a molten pool cavity 33. The molten pool cavity 33 is used to contain materials such as iron and copper. The upper surface of the bottom plate 31 is provided with a plurality of air blowing ports 311 that communicate with the molten pool cavity 33. There may be 2, 3, 4 or more air blowing ports 311. The peripheral side plate 32 is provided with a discharge port that communicates with the molten pool cavity 33. The discharge port is an openable and closable discharge port.

[0024] The gas blowing assembly 40 is mounted on the base 20. The gas blowing assembly 40 is used to blow protective gas into the molten pool cavity 33 through the gas blowing port 311. The protective gas includes, but is not limited to, nitrogen, argon, helium and carbon dioxide.

[0025] Understandably, when smelting materials using the bottom-blown converter 10, the materials can be fed into the molten pool chamber 33 and heated within it to melt. At this time, the discharge port is closed. During the smelting process, the air blowing assembly 40 injects protective gas into the molten pool chamber 33 through the air blowing port 311. The protective gas creates disturbance as it flows through the molten material, resulting in a stirring effect. This allows the material reaction within the molten pool to approach equilibrium, thereby improving the smelting efficiency and quality. After smelting is complete, the discharge port can be opened, and the molten material can be discharged through it.

[0026] More specifically, such as Figure 3 As shown, the center of the upper surface of the base plate 31 is the first center P, and multiple air inlets 311 are arranged at intervals around the first center P, with the air inlets 311 extending radially away from the first center P along the base plate 31. The base plate 31 can be disc-shaped, in which case the radial direction of the base plate 31 is the direction of its diameter extension.

[0027] It is understandable that, compared to setting the air inlet 311 only at the first center P, the airflow blown out from the air inlet 311 is unlikely to disturb the material in the edge area of ​​the molten pool cavity 33, which makes it easy for a stirring dead zone to form in the edge area of ​​the molten pool cavity 33.

[0028] In this application, on the one hand, by setting the air blowing port 311 outside the first center P and extending the air blowing port 311 away from the first center P, the distance between the air blowing port 311 and the edge of the bottom plate 31 can be shortened. This makes it easier for the airflow blown from the air blowing port 311 to disturb the material in the edge area of ​​the molten pool cavity 33, thereby reducing the probability of a stirring dead zone. On the other hand, by setting multiple air blowing ports 311 and arranging them at intervals around the first center P, protective gas can be sprayed from multiple positions, thereby forming multiple airflows at various positions. This can enhance the disturbance formed by the protective gas in the molten material, making the disturbance formed by the airflow more intense, thereby improving the stirring effect on the material and creating disturbances in more areas and directions of the material. This can reduce the probability of a stirring dead zone and further improve the reaction efficiency and quality of smelting.

[0029] In some embodiments, the radius of the base plate 31 is R, and the distance between the air outlet 311 and the first center P is r, where 0.4R ≤ r ≤ 0.6R. This ensures that the distances between the air outlet 311 and the first center P, as well as the edge of the base plate 31, are suitable, allowing the airflow from the air outlet 311 to simultaneously disturb the material in both the central and edge regions of the molten pool cavity 33. Here, r can be 0.4R, 0.45R, 0.5R, 0.6R, or other multiples of R.

[0030] In some embodiments, the radial length of the air inlet 311 along the base plate 31 is L, and the circumferential width of the air inlet 311 along the base plate 31 is d, where 10d ≤ L. This makes the air inlet 311 elongated in shape, which can increase the flow rate of the protective gas when it is ejected from the air inlet 311, prevent material from clogging the air inlet 311, and compared with circular or square shapes, the elongated air inlet 311 provides greater resistance to molten material. This can prevent molten material from flowing from the air inlet 311 to the air blowing assembly 40 while ensuring the opening area of ​​the air inlet 311. Furthermore, when the air blowing assembly 40 is activated, the protective gas... When the material is ejected from the air outlet 311, the elongated shape of the air outlet 311 makes it easier for the ejected airflow to form "mushroom head" shaped bubbles. These bubbles can push the material at the air outlet 311 to the surrounding area, thus providing good protection for the air blowing assembly 40 and extending its service life. This allows the air blowing assembly 40 to achieve a lifespan synchronized with that of the furnace body 30, reducing maintenance downtime and improving metallurgical efficiency while lowering production costs. Furthermore, the elongated shape of the air outlet 311 makes it easier to create a larger area of ​​disturbance in the region between the first center P and the edge of the bottom plate 31.

[0031] Wherein, L can be 10d, 12d, 15d, 20d, 25d, or other multiples of d. In one embodiment, d can be 1 mm and L can be 20 mm.

[0032] In some embodiments, using the upper surface of the base plate 31 as the base surface, the area within 50 mm of the base surface can be designated as the bubble generation area, the area from 50 mm to 800 mm of the base surface can be designated as the flow field agitation area, and the area above 800 mm of the base surface can be designated as the slag area. It is understood that when the blower 311 injects protective gas into the molten pool cavity 33, the airflow will generate bubbles in the bubble generation area. These bubbles can effectively isolate the molten material from the blower 311, thereby preventing the molten material from flowing from the blower 311 to the blower assembly 40 and improving the service life of the blower assembly 40. When the bubbles flow to the flow field agitation area, they can burst, generating stronger disturbances.

[0033] In addition, when the protective gas is ejected from the gas outlet 311, the temperature of the protective gas is much lower than the temperature inside the furnace. The protective gas gradually heats up during its ascent, which can play a certain role in cooling the material in the molten pool cavity 33. The closer to the gas outlet 311, the stronger the cooling effect, thereby reducing the temperature at the gas outlet 311 and preventing the gas blowing assembly 40 from being damaged by high temperature, which can further improve the service life of the gas blowing assembly 40.

[0034] In some embodiments, the plurality of air outlets 311 are rotationally symmetrical about the first center P, which can reduce the overlapping area of ​​the airflow ejected from each air outlet 311. This allows the airflow ejected from the plurality of air outlets 311 to disturb more areas, thereby further reducing the probability of the formation of a stirring dead zone with a smaller number of air outlets 311. Specifically, only two air outlets 311 may be provided, and the angle formed between two adjacent air outlets 311 can be 180 degrees, 135 degrees, 90 degrees, or other degrees.

[0035] like Figure 4 As shown, in some embodiments, the bottom plate 31 is rotatably connected to the base 20 and the peripheral side plate 32. The bottom-blown converter 10 also includes a driving component, which is mounted on the base 20 and is drively connected to the bottom plate 31. The driving component is used to drive the bottom plate 31 to rotate around a first axis K, which passes through a first center P. It can be understood that the driving component can drive the bottom plate 31 to rotate around the first axis K. When the bottom plate 31 rotates, it can form vortex disturbances in the molten material, thereby further enhancing the disturbance to the material and further improving the reaction efficiency and quality of smelting. Here, the first axis K is the centerline of the bottom plate 31.

[0036] In some embodiments, the air blowing assembly 40 includes an air blowing element 41, a first conduit 42, and a second conduit 43.

[0037] The air blowing component 41 is installed at the bottom of the base 20. The air blowing component 41 has an air outlet 411. The air blowing component 41 can be an air pump, which blows out protective gas through the air outlet 411. The first pipe 42 is disposed inside the base 20 and is rotatably connected to the base 20 around the first axis K. The second pipe 43 is disposed inside the base plate 31. The second pipe 43 is fixedly connected to the first pipe 42 and communicates with the first pipe 42 and the air outlet 311. The air outlet 411 is connected to the air outlet 311 through the first pipe 42 and the second pipe 43.

[0038] The driving component is connected to the first pipe 42 and drives the first pipe 42 to rotate around the first axis K, thereby driving the base plate 31 and the second pipe 43 to rotate around the first axis K. It can be understood that the protective gas blown from the outlet 411 of the air blowing component 41 passes through the first pipe 42 and the second pipe 43 in sequence before being ejected from the air blowing port 311. The first pipe 42 can be inserted into the air blowing port 311 and rotatably connected to the air blowing component 41. When the driving component drives the first pipe 42 to rotate relative to the base 20 and the air blowing component 41 around the first axis K, the first pipe 42 drives the base plate 31 and the second pipe 43 to rotate, thereby enabling the base plate 31 to rotate around the first axis K.

[0039] It should also be noted that the driving component can be a motor, which is mounted on the base 20 and located outside the molten pool cavity 33. The output shaft of the motor is inserted into the base 20, and a first gear can be sleeved on the output shaft. A second gear is sleeved on the outside of the first pipe 42, and the second gear meshes with the first gear. The motor drives the first gear to rotate, thereby driving the second gear and the first pipe 42 to rotate. In other embodiments, the base plate 31 can also be driven to rotate by other driving methods.

[0040] In some embodiments, the portion of the base plate 31 with the air inlet 311 can be formed of magnesium carbon material, which has good high-temperature resistance and can improve the service life of the air inlet 311. The first pipe 42 and the second pipe 43 can be made of heat-resistant steel, thereby improving the structural strength and high-temperature resistance of the first pipe 42 and the second pipe 43, and further improving the structural strength of the first pipe 42 and the second pipe 43.

[0041] In some embodiments, the peripheral side plate 32 includes a heating layer 321 and a heat insulation shell 322. The heating layer 321 is disposed around the outer periphery of the base plate 31 and is used to heat the material in the molten pool cavity 33. The heating layer 321 may be formed of graphite or other materials. The heat insulation shell 322 is disposed around the outer periphery of the heating layer 321 to provide protection and heat insulation. The heat insulation shell 322 may be formed of heat-insulating metal or other materials, such as heat-insulating steel.

[0042] A sealing structure 50 is provided between the heat insulation shell 322 and the base 20. The sealing structure 50 is arranged around the outer periphery of the heating layer 321 and around the outer periphery of the base plate 31. The heat insulation structure can achieve a seal between the heat insulation shell 322 and the base 20, and achieve a dynamic seal at the base plate 31, thereby preventing the leakage of protective gas and materials in the molten pool cavity 33.

[0043] In some embodiments, the sealing structure 50 includes multiple sealing layers 51, which are sequentially stacked along the radial direction of the base plate 31, and each of the multiple sealing layers 51 is formed of a different material. It is understood that, compared to a single sealing layer 51, multiple sealing layers 51 can provide multiple seals, thus achieving a better sealing effect. Furthermore, different sealing materials have different properties; by sequentially stacking multiple sealing layers 51 formed of different sealing materials, additional functions can be achieved beyond just sealing, such as high-temperature resistance, corrosion resistance, and deformation resistance.

[0044] The number of sealing layers 51 can be 2, 3, 4 or more. Taking 4 sealing layers as an example, the outermost first sealing layer 51 can be formed of a high-hardness metal (such as stainless steel or nickel-based alloy), giving the sealing structure 50 sufficient mechanical strength and resistance to deformation, providing elastic support for the other sealing layers 51. The inner second, third and fourth sealing layers 51 can be formed of soft metals (such as aluminum, copper, gold, silver or indium), giving them the ability to undergo plastic deformation. This plastic deformation can fill the microscopic defects and gaps between the sealing layers 51, significantly reducing the permeation path of gases (especially small molecule gases such as helium), achieving better airtightness. Reliable sealing can be achieved by utilizing the elastic deformation of the sealing material and the interlayer interface effect between the sealing layers 51, thereby further improving the sealing effect of the sealing structure 50.

[0045] In addition, a gold-plated layer or a polytetrafluoroethylene coating can be formed on the outer surface of the first sealing layer 51 to form an anti-oxidation layer or an anti-corrosion layer.

[0046] Secondly, this application also provides a metallurgical method, such as Figure 5 As shown, the metallurgical method applied to the bottom-blown converter 10 in any of the above embodiments includes: S10. The material is put into the molten pool chamber 33 and heated to melt it. The material can be heated to 1500℃ to melt it.

[0047] S20. When the material melts to the preset condition, the air blowing component 40 is activated, and the air blowing component 40 blows protective gas into the molten pool cavity 33 through the air blowing port 311. The preset condition can be that all materials have completely melted; the preset condition can also be that the height of the molten material in the molten pool cavity 33 reaches a preset value, such as half the height of the molten pool cavity 33; or the preset condition can be other conditions selected according to actual needs.

[0048] S30. Adjust the flow rate of the protective gas according to the ventilation time, so that the flow rate of the protective gas can change with the ventilation time.

[0049] S40. After the material is melted, the blowing assembly 40 is turned off, and the molten material is discharged through the discharge port.

[0050] Understandably, compared to using a constant-flow-rate protective gas to disturb the material during the smelting process to achieve the purpose of stirring, the constant-flow-rate protective gas flows more evenly and produces more concentrated bubbles. This results in a gentler disturbance of the gas flow to the molten steel in the pool, leading to a poorer stirring effect on the material and a tendency to create stirring dead zones.

[0051] In this application, the flow rate of the protective gas can be adjusted according to the duration of the protective gas venting. That is, the flow rate of the protective gas injected into the molten pool cavity 33 through the gas blowing port 311 is not constant, but varies according to the duration of the protective gas venting. This allows for the use of different flow rates of protective gas to create disturbances at different times during the smelting process. When the flow rate of the protective gas changes, stronger disturbances are generated, disrupting the stability of the entire flow field and breaking the stable flow field structure. This generates more unstable secondary eddies, which can effectively disturb the interface between the flow field stirring area and the molten slag area, preventing the molten slag from forming a crust at the interface and creating favorable conditions for the molten slag to float and be captured. In addition, the unstable secondary eddies allow the generated bubbles to become more dispersed, thereby improving the stirring effect on the material and reducing the likelihood of dead zones in the stirring.

[0052] Specifically, the duration of the protective gas venting is t, and the flow rate of the protective gas is Q. (See [reference]). Figures 6 to 10 As shown, Figures 6 to 10 This is a simulation diagram showing the change in flow velocity over time, with ventilation time as the horizontal axis and flow velocity as the vertical axis.

[0053] like Figure 6 As shown, in some embodiments, in step S30, Q and t satisfy the following: Q changes with t according to a sine function law, and Q and t can satisfy Q=sint. Of course, Q and t can also satisfy other sine function formulas. For example, the entire jetting stage of the protective gas can be divided into four stages: T1, T2, T3, and T4. In stage T1 (0-7.5s), Q increases from 208 m / s to a peak value of 232.96 m / s; in stage T2 (7.5s-15s), Q drops back from 232.96 m / s to 208 m / s; in stage T3 (15s-22.5s), Q decreases from 208 m / s to a minimum value of 183.04 m / s; in stage T4 (22.5s-30s), Q returns from 183.04 m / s to 208 m / s.

[0054] Understandably, compared to using a constant flow rate of protective gas during the smelting process, the flow rate Q of the protective gas fluctuates periodically according to the sine curve with the gas flow time t. This allows the diameter and rising speed of the bubble group generated by the protective gas to change periodically, and the entrainment and driving force on the surrounding fluid also changes periodically. This can better break the stable flow field structure, thereby exciting more unstable secondary eddies, and can effectively disturb the interface between the flow field stirring region and the slag region.

[0055] like Figure 7 As shown, in some other embodiments, in step S30, Q and t satisfy the following: Q changes with t according to a cosine function law, and Q and t can satisfy Q=cost. Of course, Q and t can also satisfy other cosine function formulas. For example, the entire jetting stage of the protective gas can be divided into four stages: T1, T2, T3, and T4. In stage T1 (0-7.5s), Q decreases from 232.96 m / s to 208 m / s; in stage T2 (7.5s-15s), Q continuously decreases from 208 m / s to a minimum value of 183.04 m / s; in stage T3 (15s-22.5s), Q increases from 183.04 m / s to 208 m / s; in stage T4 (22.5s-30s), Q continuously increases from 208 m / s to a peak value of 232.96 m / s.

[0056] Understandably, compared to using a constant flow rate of protective gas during smelting, the flow rate Q of the protective gas fluctuates periodically with the gas flow time t according to a cosine curve. This causes the diameter and rising speed of the bubble clusters generated by the protective gas to change periodically, and the entrainment and pushing forces on the surrounding fluid also change periodically. This can better disrupt the stable flow field structure, thereby exciting more unstable secondary eddies, and effectively disturbing the interface between the flow field stirring region and the slag region. Furthermore, compared to Q varying with t according to a sine function, in this embodiment, Q varies with t according to a cosine function, allowing for a higher initial flow rate of the protective gas. For melts with high viscosity, this can create a better disturbance effect at the beginning.

[0057] like Figure 8 As shown, in some other embodiments, Q increases linearly with t, and Q and t can satisfy Q=Kt, where k can be any positive number. Of course, Q and t can also satisfy other linear formulas. For example, as t increases from 0 to 30s, Q gradually increases from 180m / s to 236m / s.

[0058] Understandably, the flow rate Q of the protective gas gradually increases linearly with the ventilation time t, which is more conducive to achieving a smooth transition of the flow field and controllable energy input. This can prevent problems such as violent splashing caused by sudden changes in flow rate, and ensure a more stable smelting process. At the same time, it can precisely control the shear force of the turbulent flow in the molten pool cavity 33, making it more suitable for special smelting scenarios that are sensitive to fluid disturbances.

[0059] like Figure 9 As shown, in some other embodiments, Q increases with t in a stepwise manner. Exemplarily, the entire jetting phase of the protective gas can be divided into five stages: T1, T2, T3, T4, and T5. In stage T1 (0–6 s), Q is 139.93 m / s; in stage T2 (6 s–12 s), Q is 175.81 m / s; in stage T3 (12 s–18 s), Q is 210.97 m / s; in stage T4 (18 s–24 s), Q is 238.60 m / s; and in stage T5 (24 s–30 s), Q is 274.48 m / s.

[0060] Understandably, the flow rate Q of the protective gas increases in a stepwise manner with the aeration time t, allowing the flow rate to switch instantaneously between preset high and low values. This creates a strong "step" impact, and the sudden and intense change in flow rate can powerfully and rapidly disrupt the stable flow field structure and temperature and concentration stratification. This gives the gas flow formed by the protective gas a powerful flow field reconstruction and wall-breaking capability, which is particularly effective in eliminating stubborn "dead zones" and preventing bottom nodules. At the same time, the operation logic is simple, and the combination of high and low flow rates can balance energy saving and strong stirring requirements, making it a very direct and efficient stirring mode for solving specific process problems.

[0061] like Figure 10 As shown, in some other embodiments, Q changes randomly with t, that is, Q changes randomly in an unordered manner.

[0062] Understandably, the flow rate of the protective gas ejected by the blowing component 41 can be driven by a deterministic non-periodic signal, making the flow rate change of the protective gas appear random on a macroscopic level, but in fact containing precise laws. This can stimulate the theoretically optimal chaotic flow field, ensuring that the alloying elements and temperature in every corner of the molten pool cavity 33 can be highly uniformly distributed through non-repeating, extreme stretching and folding. Secondly, the generated chaotic flow field can not only greatly accelerate the transport of reactants, but also more easily generate and maintain tiny bubbles, providing a huge gas-liquid interface for refining reactions such as deoxidation and desulfurization, thereby significantly improving the reaction efficiency of smelting. In addition, these bubbles moving in complex motion in the chaotic flow field can more effectively capture and carry inclusions to the slag area, thereby achieving deep purification of the molten metal.

[0063] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A bottom-blown converter, characterized in that, include: Base; A furnace body is disposed on the base. The furnace body includes a bottom plate and peripheral side plates arranged around the outer periphery of the bottom plate. The peripheral side plates are connected to the bottom plate to form a molten pool cavity together with the bottom plate. The upper surface of the base plate is provided with a plurality of air blowing ports communicating with the molten pool cavity, and the peripheral side plate is provided with a discharge port communicating with the molten pool cavity. An air blowing assembly is mounted on the base, and the air blowing assembly is used to blow protective gas into the molten pool cavity through the air blowing port; The center of the upper surface of the base plate is the first center, and the plurality of air inlets are arranged at intervals around the first center, and the air inlets extend radially away from the first center along the base plate.

2. The bottom-blown converter according to claim 1, characterized in that, The radius of the base plate is R, and the distance between the air inlet and the first center is r, where 0.4R≤r≤0.6R.

3. The bottom-blown converter according to claim 1, characterized in that, The length of the air inlet along the radial direction of the base plate is L, and the width of the air inlet along the circumferential direction of the base plate is d, where 10d≤L.

4. The bottom-blown converter according to claim 1, characterized in that, The plurality of air inlets are rotationally symmetrical about the first center.

5. The bottom-blown converter according to claim 1, characterized in that, The bottom plate is rotatably connected to the base and the peripheral side plate. The bottom-blown converter also includes a driving component, which is installed on the base and is connected to the bottom plate in a transmission manner. The driving component is used to drive the bottom plate to rotate around a first axis, which passes through the first center.

6. The bottom-blown converter according to claim 5, characterized in that, The air blowing assembly includes: An air blowing component is installed at the bottom of the base, and the air blowing component has an air outlet; A first pipe is disposed within the base and is rotatably connected to the base about a first axis; The second pipe is disposed inside the base plate. The second pipe is fixedly connected to the first pipe and communicates with the first pipe and the air outlet. The air outlet is connected to the air outlet through the first pipe and the second pipe. The driving component is connected to the first pipe and is used to drive the first pipe to rotate around the first axis, thereby driving the base plate and the second pipe to rotate around the first axis.

7. The bottom-blown converter according to claim 5, characterized in that, The peripheral side plate includes a heating layer and a heat insulation shell. The heating layer is arranged around the outer periphery of the base plate and is used to heat the material in the molten pool cavity. The heat insulation shell is arranged around the outer periphery of the heating layer. A sealing structure is provided between the heat insulation shell and the base, and the sealing structure is arranged around the outer periphery of the heating layer and around the outer periphery of the base plate.

8. The bottom-blown converter according to claim 7, characterized in that, The sealing structure includes multiple sealing layers, which are stacked sequentially along the radial direction of the base plate, and each of the multiple sealing layers is formed of a different material.

9. A metallurgical method, characterized in that, Applied to the bottom-blown converter as described in any one of claims 1 to 8, the metallurgical method comprises: The material is fed into the molten pool cavity and heated to melt it. When the material melts to a preset condition, the air blowing assembly is activated, and the air blowing assembly blows the protective gas into the molten pool cavity through the air blowing port. The flow rate of the protective gas is adjusted according to the duration of the protective gas venting. After the material is melted, the blowing assembly is turned off, and the molten material is discharged through the discharge port.

10. The metallurgical method according to claim 9, characterized in that, The ventilation time of the protective gas is t, and the flow rate of the protective gas is Q. In the step of adjusting the flow rate of the protective gas according to the ventilation time, Q and t satisfy: The Q varies with t according to a sinusoidal function; or... The Q varies with t according to a cosine function; or... The Q increases linearly with t; or, The Q increases with t in a stepwise manner; or... Q varies randomly with t.

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