A top and bottom combined blowing converter and a method for systematically improving the high-intensity combined blowing effect of a large converter

Abstract

The present invention discloses a top and bottom combined blowing converter and a method for systematically improving the high-strength combined blowing effect of a large converter, and belongs to the technical field of steel smelting. The present invention divides 16 bottom guns into Group A, Group B, Group C and Group D and arranges them at the bottom of the converter body. Each group is distributed on concentric circles with the center of the bottom as the center. The number of bottom guns in Group A is 2, the number of bottom guns in Group B is 6, the number of bottom guns in Group C is 6, and the number of bottom guns in Group D is 2. The flow rate of the bottom gun in the converter tapping process is linked according to the angle. The present invention designs the bottom blowing gas supply mode, bottom blowing gas supply control, bottom blowing gas selection, bottom gun layout and top and bottom gas supply coordinated control scheme of a large converter to improve the top and bottom combined blowing intensity of the converter, extend the combined blowing life of the converter, control the carbon oxygen product mean value of the furnace service to within 0.0018, and control most of the carbon oxygen product in the later stage of the furnace service to within 0.0020.

Description

Technical Field

[0001] The present invention relates to the technical field of steel smelting, and in particular to a top and bottom combined blowing converter and a method for systematically improving the high-strength combined blowing effect of a large converter. Background Art

[0002] At present, large-scale converters at home and abroad basically adopt the top and bottom combined blowing process, which provides high-pressure airflow to the molten pool through the bottom gun, further enhancing the stirring intensity of the molten pool and providing good kinetic conditions for the chemical reaction in the furnace, which is beneficial to reducing the oxygen content of molten steel and improving the dephosphorization capacity of the converter.

[0003] At present, the main function of the converter bottom gun is to assist the oxygen jet of the top gun, and to provide high-pressure airflow from the bottom of the furnace to further strengthen the stirring of the molten pool. Therefore, the layout of the bottom gun is basically located outside the sixth ring. In this way, the stirring power source of the molten pool in the middle part is still mainly the oxygen jet of the top gun. When the oxygen gun is raised above the blowing point after the converter blowing is completed, the stirring capacity of the molten pool in the middle part is weakened due to the disappearance of the top oxygen jet, which is not conducive to the various chemical reactions in the furnace in the post-stirring stage, and may cause problems such as overoxidation of molten steel, high oxidation of final slag, and weakened dephosphorization capacity.

[0004] The carbon-oxygen accumulation value of the converter is a quantitative indicator to measure the effect of combined blowing. In the early stage of the furnace, it can be stably controlled within 0.0017. As the furnace age increases, the bottom blowing effect weakens. In the later stage of the furnace, the carbon-oxygen accumulation value is mostly above 0.0020. On the one hand, it affects the reaction kinetics of the converter and increases the risk of controlling the composition of the molten steel. On the other hand, it will cause the oxygen content of the molten steel at the end of the converter to be too high, increase the consumption of deoxidizers, and is not conducive to improving the quality of the molten steel and stabilizing the condition of the converter. Therefore, with the increase in the number of large converters, how to effectively improve the combined blowing effect of large converters and extend the combined blowing life of large converters is the goal and research object pursued by most steelmaking practitioners at this stage. At present, there are many methods for improving the bottom gun and bottom blowing control of the converter separately, but there is no method for systematically improving the combined blowing effect of large converters with long furnace life. Summary of the invention

[0005] 1. Technical problem to be solved by the invention

[0006] In view of the above-mentioned deficiencies in the prior art, the present invention provides a top and bottom combined blowing converter and a method for systematically improving the high-intensity combined blowing effect of a large converter; the present invention designs the bottom blowing gas supply mode, bottom blowing gas supply control, bottom blowing gas selection, bottom gun layout and top and bottom gas supply coordinated control scheme of the large converter to improve the top and bottom combined blowing intensity of the converter, extend the combined blowing life of the converter, control the average carbon-oxygen product during the furnace service to within 0.0018, and control most of the carbon-oxygen products in the later stage of the furnace service to within 0.0020.

[0007] 2. Technical solution

[0008] In order to achieve the above object, the technical solution provided by the present invention is:

[0009] A top and bottom double-blown converter of the present invention comprises a converter body and 16 bottom guns; the 16 bottom guns are divided into groups A, B, C and D and are arranged at the furnace bottom of the converter body, and each group is distributed on concentric circles with the center of the furnace bottom as the center; wherein: the radius of the concentric circle A where the bottom guns of group A are located is 1400-2000mm, the radius of the concentric circle B where the bottom guns of group B are located is 1100-1700mm; the radius of the concentric circle C where the bottom guns of group C are located is 700-1300mm; the radius of the concentric circle D where the bottom guns of group D are located is 200-800mm.

[0010] Furthermore, the number of bottom guns in group A is 2, wherein the angle between the bottom gun A1 and the steel outlet is 15-35 degrees, and the angle between the bottom gun A2 and the steel outlet is 325-345 degrees.

[0011] Furthermore, the number of bottom guns in group B is 6, among which the angle between bottom gun B1 and the steel outlet is 25-55 degrees, the angle between bottom gun B2 and the steel outlet is 115-145 degrees, the angle between bottom gun B3 and the steel outlet is 145-175 degrees, the angle between bottom gun B4 and the steel outlet is 185-210 degrees, the angle between bottom gun B5 and the steel outlet is 220-245 degrees, and the angle between bottom gun B6 and the steel outlet is 315-345 degrees.

[0012] Furthermore, the number of bottom guns in group C is 6, among which the angle between bottom gun C1 and the steel outlet is 55-75 degrees, the angle between bottom gun C2 and the steel outlet is 80-100 degrees, the angle between bottom gun C3 and the steel outlet is 105-125 degrees, the angle between bottom gun C4 and the steel outlet is 235-255 degrees, the angle between bottom gun C5 and the steel outlet is 260-280 degrees, and the angle between bottom gun C6 and the steel outlet is 285-305 degrees.

[0013] Furthermore, the number of bottom guns in group D is 2, wherein the angle between the bottom gun D1 and the steel outlet is 10-170 degrees, and the angle between the bottom gun D2 and the steel outlet is 190-350 degrees.

[0014] The present invention provides a systematic method for improving the high-intensity combined blowing effect of a large converter. During the process of bottom blowing of the converter body by the 16 bottom guns, the high-intensity combined blowing effect of the converter is improved by controlling the bottom blowing gas supply mode of the converter, the linkage adjustment of the bottom blowing gas supply flow rate and the tilting angle of the converter, the bottom blowing gas selection and the coordination of top and bottom combined blowing.

[0015] Furthermore, four converter bottom blowing gas supply modes are set, namely: strong stirring mode, weak stirring mode, maintenance mode and special mode, and the bottom blowing gas supply flow rate range is set to 0.02Nm 3 / h-0.20Nm 3 / h; Among them: the flow setting values ​​of the 16 bottom guns are the same in strong stirring mode, weak stirring mode and maintenance mode; in special mode, different bottom blowing flow values ​​are set for each bottom gun in each stage of converter production according to the residual thickness of the furnace bottom, the bottom blowing visualization and the refractory materials of the furnace body.

[0016] Furthermore, each bottom gun of the converter has two gas sources. The bottom blowing gas flow rate and type of bottom blowing gas during the blowing process are adjusted and switched according to the setting table. The bottom blowing flow rate during the steelmaking process is adjusted in conjunction with the tilting angle of the converter. The bottom blowing gas supply flow rate of the bottom gun immersed in the molten steel is executed according to the set value, and the bottom blowing gas supply flow rate of the bottom gun exposed to the outside is automatically adjusted from the set value to the minimum value.

[0017] Furthermore, there are four options for selecting the bottom blowing gas for the converter:

[0018] Solution 1: Nitrogen is used as the bottom blowing gas for 16 bottom guns throughout the process;

[0019] Solution 2: 16 bottom guns use argon as the bottom blowing gas from the time of iron charging to the end of steel tapping; nitrogen is used as the bottom blowing gas from the start of slag splashing to the time of iron charging in the lower furnace;

[0020] Scheme 3: 16 bottom guns use nitrogen as the bottom blowing gas from the iron charging to the silicon-manganese oxidation period; from the early stage of carbon-oxygen reaction to the end of steel tapping, argon is used as the bottom blowing gas; from the beginning of slag splashing to the iron charging in the lower furnace, nitrogen is used as the bottom blowing gas;

[0021] Solution 4: Personalize the gas selected for each bottom gun in different smelting stages and set it to nitrogen or argon individually, that is, nitrogen and argon will exist in the bottom blowing gas at the same time.

[0022] Furthermore, the oxygen flow rate in the middle and late stages of smelting is controlled to be 60000-64000Nm 3 / h, oxygen lance position is 1.8m-2.1m, bottom blowing air supply intensity is 0.08-0.20Nm 3 / (t·min).

[0023] 3. Beneficial effects

[0024] Compared with the existing known technologies, the technical solution provided by the present invention has the following significant effects:

[0025] (1) A method for systematically improving the high-intensity combined blowing effect of a large converter of the present invention, in which 16 bottom guns are arranged on four concentric circles with the center of the furnace bottom as the center, and the flow rate of the bottom guns during the converter tapping process is linked according to the angle, so that the bottom guns immersed in the molten steel can still provide a certain stirring effect for the molten pool during the tapping process, thereby reducing the degree of slag foaming, reducing the possibility of slag under the furnace mouth and the amount of slag entrained by the steel flow;

[0026] (2) A method for systematically improving the high-intensity combined blowing effect of a large converter according to the present invention, wherein two different types of gases can exist simultaneously in the bottom stirring of the converter at the same time, and the gas flow rate of the bottom gun can be differentially controlled to meet the production and production maintenance requirements under different conditions;

[0027] (3) A method for systematically improving the high-intensity combined blowing effect of a large converter according to the present invention improves the stirring degree in the furnace under the premise of stable converter blowing by coordinated control of the converter oxygen lance position, the converter oxygen flow rate and the converter bottom blowing gas supply intensity;

[0028] (4) The present invention provides a systematic method for improving the high-intensity re-blowing effect of a large converter, which can reduce the carbon-oxygen accumulation value of the converter to below 0.0018 during the service life, and the minimum carbon-oxygen accumulation value during the service life can be controlled within 0.0015, which is beneficial to reducing the oxygen content of the molten steel at the end of the converter and improving the quality of the molten steel. At the same time, the strong stirring function of the steel-making process can further improve the dephosphorization rate of the converter, which is beneficial to stable component control and improve the retention rate of molten steel components. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is the bottom gun layout design diagram. Figure 1 The left side is the feeding side, and the right side is the steel tapping side;

[0030] Figure 2 This is a schematic diagram of the top and bottom combined blowing coordination of the converter;

[0031] Figure 3 This is the converter production process flow chart;

[0032] Figure 4 This is a schematic diagram of bottom blowing arrangement. Figure 4 The left side is the charging side, the right side is the steel tapping side, and there are 16 air-permeable bricks at the bottom of the furnace;

[0033] Figure 5 This is a real shot of the scene;

[0034] Figure 6 This is a schematic diagram of top and bottom combined blowing coordination for the 18th campaign of the 2# converter;

[0035] Figure 7 This is a schematic diagram of carbon and oxygen accumulation control in the 18th campaign of the No. 2 converter. DETAILED DESCRIPTION

[0036] In order to further understand the content of the present invention, the present invention is described in detail in conjunction with the accompanying drawings and embodiments.

[0037] The present invention aims at various factors that affect the top and bottom combined blowing of a large-scale converter, and systematically designs the bottom blowing gas supply mode, bottom blowing gas supply control, bottom blowing gas selection, bottom gun layout and top and bottom combined blowing coordination of the converter, thereby enhancing the coordinated operation fit of the top blowing and bottom blowing of the converter, while enhancing the bottom stirring effect in the late stage of converter blowing and the steelmaking process, while accelerating the uniformity of molten steel composition, promoting the steel-slag interface reaction rate, reducing the carbon-oxygen accumulation value of the converter, and reducing the active oxygen content of the molten steel, so as to slow down the erosion rate of the furnace lining and bottom blowing components, and benignly promoting the effect and life of the top and bottom combined blowing of the large-scale converter.

[0038] (1) Converter bottom blowing gas supply mode

[0039] The present invention sets 4 converter bottom blowing gas supply modes, and the bottom blowing gas supply flow rate range is 0.02Nm 3 / h-0.20Nm 3 / h. Figure 3 According to the converter production process, the present invention divides the entire process into 12 stages: iron addition, silicon-manganese oxidation period, initial carbon-oxygen reaction, middle carbon-oxygen reaction, final carbon-oxygen reaction, auxiliary blowing, static stirring, measurement, steel tapping, slag splashing, slag turning, and waiting; the bottom blowing gas supply intensity under different stages and different gas supply modes is shown in Table 1.

[0040] Table 1 Converter bottom blowing gas supply mode

[0041]

[0042] Note: The unit of bottom blowing air supply intensity in the table is Nm 3 / (t.min).

[0043] In the above modes, the flow setting values ​​of the 16 bottom guns are the same for the strong stirring mode, weak stirring mode and maintenance mode; in the special mode, different bottom blowing flow values ​​can be set for each bottom gun in each stage according to factors such as the residual thickness of the furnace bottom, the visualization of bottom blowing, the refractory conditions of the furnace body, etc., to meet the special needs of production control and slow down the melting rate of the bottom blowing components.

[0044] (2) Bottom blowing air supply control

[0045] Each bottom gun of the converter has two gas sources, nitrogen source and argon source. The gas source switching of the 16 bottom guns is controlled by 32 shut-off valves. The bottom blowing gas flow and bottom blowing gas type during the blowing process are adjusted and switched according to the setting table. The bottom blowing flow during the steelmaking process is linked to the tilting angle of the converter. The bottom blowing gas flow of the bottom gun immersed in the molten steel is executed according to the set value, and the bottom blowing gas flow of the bottom gun exposed to the outside is automatically adjusted from the set value to the guaranteed bottom value. The specific plan is shown in Table 2:

[0046] Table 2 Bottom blowing flow rate and furnace angle linkage adjustment table

[0047] Furnace body angle A1 A2 B1 B2 B3 B4 B5 B6 C1 C2 C3 C4 C5 C6 D1 D2 330° SD SD SD SD 0.02 0.02 SD SD SD SD SD SD SD SD SD SD 310° SD SD SD 0.02 0.02 0.02 0.02 SD SD SD SD SD SD SD SD SD 295° SD SD SD 0.02 0.02 0.02 0.02 SD SD SD 0.02 0.02 SD SD 0.02 0.02 280° SD SD SD 0.02 0.02 0.02 0.02 SD SD 0.02 0.02 0.02 0.02 SD 0.02 0.02 272° SD SD SD 0.02 0.02 0.02 0.02 SD 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 267° SD SD 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 264° 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02 0.02

[0048] Note: 1. SD in the table represents the set value; 2. The unit of bottom blowing air supply intensity in the table is Nm 3 / (t·min).

[0049] (3) Selection of bottom blowing gas

[0050] There are four options for selecting converter bottom blowing gas:

[0051] Solution 1: Nitrogen is used as the bottom blowing gas for 16 bottom guns throughout the process;

[0052] Solution 2: 16 bottom guns use argon as the bottom blowing gas from the time of iron charging to the end of steel tapping; nitrogen is used as the bottom blowing gas from the start of slag splashing to the time of iron charging in the lower furnace;

[0053] Scheme 3: 16 bottom guns use nitrogen as the bottom blowing gas from the iron charging to the silicon-manganese oxidation period; from the early stage of carbon-oxygen reaction to the end of steel tapping, argon is used as the bottom blowing gas; from the beginning of slag splashing to the iron charging in the lower furnace, nitrogen is used as the bottom blowing gas;

[0054] Solution 4: Personalize the gas selected for each bottom gun in different smelting stages and set it to nitrogen or argon individually, that is, nitrogen and argon will exist in the bottom blowing gas at the same time.

[0055] Table 3 Bottom blowing gas selection plan

[0056]

[0057] (4) Bottom gun layout:

[0058] See also Figure 1 The number of bottom guns designed by the present invention is 16, which are divided into 4 groups (Group A, Group B, Group C, and Group D), and each group is distributed on concentric circles with the center of the furnace bottom as the center.

[0059] The number of bottom guns allocated to group A is 2. The radius of the concentric circle A where the bottom guns are located is 1400-2000mm, of which the angle between A1 and the tapping port is 15-35 degrees, and the angle between A2 and the tapping port is 325-345 degrees;

[0060] The number of bottom guns allocated to group B is 6, and the radius of the concentric circle B where the bottom gun is located is 1100-1700mm, among which the angle between B1 and the tapping port is 25-55 degrees, the angle between B2 and the tapping port is 115-145 degrees, the angle between B3 and the tapping port is 145-175 degrees, the angle between B4 and the tapping port is 185-210 degrees, the angle between B5 and the tapping port is 220-245 degrees, and the angle between B6 and the tapping port is 315-345 degrees;

[0061] The number of bottom guns allocated to group C is 6, and the radius of the concentric circle C where the bottom gun is located is 700-1300mm, among which the angle between C1 and the tapping port is 55-75 degrees, the angle between C2 and the tapping port is 80-100 degrees, the angle between C3 and the tapping port is 105-125 degrees, the angle between C4 and the tapping port is 235-255 degrees, the angle between C5 and the tapping port is 260-280 degrees, and the angle between C6 and the tapping port is 285-305 degrees;

[0062] The number of bottom guns allocated to group D is 2, and the radius of the concentric circle D where the bottom guns are located is 200-800mm, among which the angle between D1 and the steel outlet is 10-170 degrees, and the angle between D2 and the steel outlet is 190-350 degrees.

[0063] (5) Top and bottom blowing:

[0064] See also Figure 2 In the early stage of smelting, the carbon-oxygen reaction is intense. Therefore, the oxygen lance flow rate, oxygen lance position and bottom lance gas supply intensity in the early stage are mainly for stable blowing. In the middle and late stages, the degree of stirring of the molten pool is increased to provide favorable kinetic conditions for the reaction in the furnace. The oxygen flow rate is controlled at 60000-64000Nm in the middle and late stages of smelting. 3 / h, oxygen lance position is 1.8m-2.1m, bottom blowing air supply intensity is 0.08-0.20Nm 3 / (t·min).

[0065] In the present invention, examples of bottom blowing flow rate settings in 12 stages are shown in Table 4:

[0066] Table 4 Bottom Blowing Flow Setting Table

[0067]

[0068] Note: The unit of bottom blowing air supply intensity in the table is Nm 3 / h.

[0069] For the 12 stages, see Table 5 for examples of bottom blowing gas selection:

[0070] Table 5 Bottom Blowing Gas Selection Table

[0071]

[0072] Example 1

[0073] Implementation furnace base: No. 2 converter of a steel rolling mill (nominal tonnage: 300 tons; top and bottom blown converter; 16 bottom guns).

[0074] The 18th campaign of the No. 2 converter of a certain steel rolling mill will start from December 10, 2021 to June 28, 2022. By changing the bottom gun layout, the bottom blowing gas supply mode and the top and bottom combined blowing coordination mode are preset and implemented, and the bottom gun is visually monitored daily and the bottom blowing gas supply parameters are adjusted in stages.

[0075] The number of converter bottom guns increased to 16, and the bottom gun layout was changed to be distributed on four rings (4 rings, 6 rings, 8 rings and 9 rings), including: 2 on the 4 ring, symmetrically distributed, close to the charging side; 6 on the 6 ring, distributed on both sides of the horizontal and vertical axes of the furnace bottom; 6 on the 8 ring, symmetrically distributed, 4 close to the charging side, 2 close to the steel tapping side; 2 on the 9 ring, symmetrically distributed, close to the steel tapping side. The bottom gun type is annular seam bottom gun, and the specific layout is as follows Figure 4 and Figure 5 .

[0076] This bottom gun layout can enhance the action area of ​​bottom blowing gas supply and stirring, improve the bottom blowing stirring effect, and cooperate with high-intensity top blowing to make the temperature and composition of molten steel in the top and bottom molten pools uniform, so as to stabilize the converter blowing and accelerate the steel-slag interface reaction in the furnace.

[0077] The converter bottom blowing gas supply intensity is controlled according to the bottom blowing setting table, with a total of 6 modes, including 2 strong stirring modes, 3 medium stirring modes, and one maintenance mode. The specific parameter setting table is as follows:

[0078] Table 6 Bottom Blowing Flow Setting Table

[0079]

[0080] The bottom blowing mode is selected by the operator after comprehensively considering the furnace bottom thickness measurement data, bottom blowing visualization and carbon-oxygen accumulation value of the day; under normal circumstances, N2 is used in the "iron addition-carbon oxidation mid-stage" and "slag splashing-waiting" stages of bottom blowing, and Ar is used in the remaining stages. When there are special requirements for the steel grade, the bottom blowing gas will be switched to "argon blowing throughout the process" or "nitrogen blowing throughout the process".

[0081] The converter top blowing is mainly set based on the silicon content of molten iron, and the flow rate setting value is 950Nm 3 / min-1080Nm 3 / min, the gun position control is low-high-low, and the oxygen supply intensity of the oxygen gun is controlled at 63000Nm most of the time. 3 / h, providing good kinetic conditions for the steel-slag interface reaction, and the oxygen lance gas supply intensity in the auxiliary blowing and pressure lance stage was increased to 65000Nm 3 / h, further accelerate the steel-slag interface reaction, reduce the oxidizability of the converter final slag, and reduce the carbon-oxygen accumulation value of the converter. For specific settings, see Table 7.

[0082] Table 7 Oxygen content, position grabbing and oxygen flow setting table at different smelting stages

[0083]

[0084] Note: 1) Oxygen unit: m 3 ; 2) Gun position is relative to the gun position, unit: cm; 3) Oxygen flow unit: Nm 3 / min

[0085] The top and bottom combined blowing coordination of the 2# converter in the 18th campaign is as follows: Figure 6 shown.

[0086] Depend on Figure 6 It can be seen that the top and bottom combined blowing coordination of the 18th campaign of the 2# converter is based on the premise of stable blowing control to improve the top and bottom combined blowing effect. Therefore, in the "early stage of carbon-oxygen reaction", a higher gun position and lower oxygen and bottom blowing flow rates are adopted. From the middle stage of carbon-oxygen reaction, the converter smelting gun position is gradually lowered, and the oxygen gun gas supply and bottom blowing gas supply intensity are increased to increase the top and bottom stirring intensity. Strong stirring at the top can provide kinetic conditions for the steel-slag interface reaction surface, and strong stirring at the bottom can promote the uniformity of the molten pool temperature and composition. While stabilizing the converter smelting control, it can provide good kinetic and thermodynamic conditions for the steel-slag interface. The above-mentioned top and bottom combined blowing coordination can maximize the smelting advantages of the top and bottom combined blowing converter, realize the "double low" control of low oxygen and low carbon in the converter under the premise of stable blowing, delay the lining erosion rate, and stabilize the converter furnace type control.

[0087] By sorting out the data of the furnace campaign, the top and bottom combined blowing effect of the 2# converter in the 18th furnace campaign was good. The carbon and oxygen accumulation value of the converter at the end of the furnace campaign could still be controlled within 0.0016, and the average carbon and oxygen accumulation value of the whole furnace campaign was 0.00159. The carbon and oxygen accumulation control situation of the 2# converter at different furnace age stages in the 18th furnace campaign is shown in the figure below: Figure 7 shown.

[0088] The present invention and its embodiments are described schematically above, and the description is not restrictive. The drawings show only one embodiment of the present invention, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired by it and designs a structural method and an embodiment similar to the technical solution without creativity without departing from the purpose of the invention, they shall all fall within the protection scope of the present invention.

Claims

1. A top and bottom blown converter, characterized in that: The converter comprises a converter body and 16 bottom guns; the 16 bottom guns are divided into groups A, B, C and D and are arranged at the bottom of the converter body, and each group is distributed on concentric circles with the center of the bottom as the center; wherein: the radius of the concentric circle A where the bottom guns of group A are located is 1400-2000mm, the radius of the concentric circle B where the bottom guns of group B are located is 1100-1700mm; the radius of the concentric circle C where the bottom guns of group C are located is 700-1300mm; the radius of the concentric circle D where the bottom guns of group D are located is 200-800mm; There are 2 bottom guns in group A, of which the angle between bottom gun A1 and the steel outlet is 15-35 degrees, and the angle between bottom gun A2 and the steel outlet is 325-345 degrees; The number of bottom guns in group B is 6, among which the angle between bottom gun B1 and the steel tapping port is 25-55 degrees, the angle between bottom gun B2 and the steel tapping port is 115-145 degrees, the angle between bottom gun B3 and the steel tapping port is 145-175 degrees, the angle between bottom gun B4 and the steel tapping port is 185-210 degrees, the angle between bottom gun B5 and the steel tapping port is 220-245 degrees, and the angle between bottom gun B6 and the steel tapping port is 315-345 degrees; The number of bottom guns in group C is 6, among which the angle between bottom gun C1 and the steel outlet is 55-75 degrees, the angle between bottom gun C2 and the steel outlet is 80-100 degrees, the angle between bottom gun C3 and the steel outlet is 105-125 degrees, the angle between bottom gun C4 and the steel outlet is 235-255 degrees, the angle between bottom gun C5 and the steel outlet is 260-280 degrees, and the angle between bottom gun C6 and the steel outlet is 285-305 degrees; The number of bottom guns in group D is 2, of which the angle between bottom gun D1 and the steel outlet is 10-170 degrees, and the angle between bottom gun D2 and the steel outlet is 190-350 degrees.

2. A method for systematically improving the high-intensity combined blowing effect of a large converter, characterized in that: In the process of bottom blowing the converter body by 16 bottom guns as described in claim 1, the high-intensity combined blowing effect of the converter is improved by controlling the bottom blowing gas supply mode of the converter, the linkage adjustment of the bottom blowing gas supply flow rate and the tilting angle of the converter, the selection of bottom blowing gas and the coordination of top and bottom combined blowing.

3. A method for systematically improving the high-intensity combined blowing effect of a large converter according to claim 2, characterized in that: Set 4 converter bottom blowing gas supply modes: strong stirring mode, weak stirring mode, maintenance mode and special mode. The bottom blowing gas supply flow rate range is set to 0.02Nm 3 / h-0.20Nm 3 / h; Among them: the flow setting values ​​of the 16 bottom guns are the same in strong stirring mode, weak stirring mode and maintenance mode; in special mode, different bottom blowing flow values ​​are set for each bottom gun in each stage of converter production according to the residual thickness of the furnace bottom, the bottom blowing visualization and the refractory materials of the furnace body.

4. A method for systematically improving the high-intensity combined blowing effect of a large converter according to claim 3, characterized in that: Each bottom gun of the converter has two gas sources. The bottom blowing gas flow and type of bottom blowing gas during the blowing process are adjusted and switched according to the setting table. The bottom blowing flow during the steelmaking process is adjusted in conjunction with the tilting angle of the converter. The bottom blowing gas supply flow of the bottom gun immersed in the molten steel is executed according to the set value, and the bottom blowing gas supply flow of the bottom gun exposed to the outside is automatically adjusted from the set value to the minimum value.

5. A method for systematically improving the high-intensity combined blowing effect of a large converter according to claim 4, characterized in that: There are four options for selecting converter bottom blowing gas: Solution 1: Nitrogen is used as the bottom blowing gas for 16 bottom guns throughout the process; Solution 2: 16 bottom guns use argon as the bottom blowing gas from the time of iron charging to the end of steel tapping; nitrogen is used as the bottom blowing gas from the start of slag splashing to the time of iron charging in the lower furnace; Scheme 3: 16 bottom guns use nitrogen as the bottom blowing gas from the iron charging to the silicon-manganese oxidation period; from the early stage of carbon-oxygen reaction to the end of steel tapping, argon is used as the bottom blowing gas; from the beginning of slag splashing to the iron charging in the lower furnace, nitrogen is used as the bottom blowing gas; Solution 4: Personalize the gas selected for each bottom gun in different smelting stages and set it to nitrogen or argon individually, that is, nitrogen and argon will exist in the bottom blowing gas at the same time.

6. A method for systematically improving the high-intensity combined blowing effect of a large converter according to claim 5, characterized in that: Control the oxygen flow rate in the middle and late stages of smelting to 60000-64000Nm 3 / h, oxygen lance position is 1.8m-2.1m, bottom blowing air supply intensity is 0.08-0.20Nm 3 / (t · min).

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