CN115637307B - Converter and control method of converter bottom blowing - Google Patents
Converter and control method of converter bottom blowing Download PDFInfo
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- CN115637307B CN115637307B CN202211209382.XA CN202211209382A CN115637307B CN 115637307 B CN115637307 B CN 115637307B CN 202211209382 A CN202211209382 A CN 202211209382A CN 115637307 B CN115637307 B CN 115637307B
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- 238000007664 blowing Methods 0.000 title claims abstract description 384
- 238000000034 method Methods 0.000 title claims abstract description 34
- 230000007246 mechanism Effects 0.000 claims abstract description 78
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 31
- 229910052760 oxygen Inorganic materials 0.000 claims description 31
- 239000001301 oxygen Substances 0.000 claims description 31
- 229910000831 Steel Inorganic materials 0.000 abstract description 34
- 239000010959 steel Substances 0.000 abstract description 34
- 238000003723 Smelting Methods 0.000 abstract description 19
- CSJDCSCTVDEHRN-UHFFFAOYSA-N methane;molecular oxygen Chemical compound C.O=O CSJDCSCTVDEHRN-UHFFFAOYSA-N 0.000 abstract description 13
- 239000011449 brick Substances 0.000 description 23
- 230000000694 effects Effects 0.000 description 14
- 230000008569 process Effects 0.000 description 10
- 239000007789 gas Substances 0.000 description 7
- 230000008901 benefit Effects 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 239000000203 mixture Substances 0.000 description 5
- 230000004048 modification Effects 0.000 description 5
- 238000012986 modification Methods 0.000 description 5
- 238000003756 stirring Methods 0.000 description 4
- 238000009825 accumulation Methods 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 238000005261 decarburization Methods 0.000 description 3
- 239000002893 slag Substances 0.000 description 3
- 238000009628 steelmaking Methods 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 229910052698 phosphorus Inorganic materials 0.000 description 2
- 239000011574 phosphorus Substances 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 238000005507 spraying Methods 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- 230000001154 acute effect Effects 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 230000004075 alteration Effects 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000009828 non-uniform distribution Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
Abstract
The invention discloses a converter and a control method of converter bottom blowing, wherein the converter comprises a first bottom blowing mechanism and a second bottom blowing mechanism; the second bottom blowing mechanism comprises N bottom blowing elements, and is arranged on the circumference of the ellipse; the ellipse is positioned at the bottom of the converter and comprises a short shaft and a long shaft, the short shaft direction is the trunnion direction of the converter, and the long shaft direction is perpendicular to the trunnion direction; the length of the long shaft is equal to the diameter of the converter bottom in the long shaft direction or the diameter of the converter bottom in the short shaft direction, and the length of the short shaft is 60% -63% of the length of the long shaft; n is more than or equal to 4 and is an even number; the first bottom blowing mechanism comprises N bottom blowing elements, and is arranged on the circumference of an inscribed circle of the ellipse, and the center of the inscribed circle is positioned at the midpoint of the short axis of the ellipse. By adopting the converter with the bottom blowing element arrangement, an asymmetric bottom blowing flow field can be formed at the bottom of a molten pool, so that the carbon-oxygen volume in molten steel is obviously reduced when the converter is tapped, and the smelting quality of the molten steel is improved.
Description
Technical Field
The application relates to the technical field of converter steelmaking, in particular to a converter and a control method of converter bottom blowing.
Background
At present, in the steelmaking field, a top-bottom combined blown converter shows a better metallurgical effect in the process of smelting high-quality steel. If the converter has good bottom blowing, the purity of molten steel can be improved, the oxygen content of the molten steel can be reduced, and the generation of inclusions after initial deoxidation can be further reduced. Currently, one of the key factors limiting further improvement of metallurgical effects is how to improve the bottom blowing effect of the converter.
Disclosure of Invention
The invention provides a converter and a control method of converter bottom blowing, which aim to solve or partially solve the technical problem of how to further improve the converter bottom blowing effect in the molten steel smelting process.
To solve the above technical problems, in a first aspect, according to an embodiment of the present invention, there is provided a converter including a first bottom blowing mechanism and a second bottom blowing mechanism;
the second bottom blowing mechanism comprises N bottom blowing elements, and is arranged on the circumference of the ellipse; the ellipse is positioned at the bottom of the converter and comprises a short shaft and a long shaft, the short shaft direction is the trunnion direction of the converter, and the long shaft direction is perpendicular to the trunnion direction; the length of the long shaft is equal to the diameter of the converter bottom in the long shaft direction or the diameter of the converter bottom in the short shaft direction, and the length of the short shaft is 60% -63% of the length of the long shaft; n is more than or equal to 4 and is an even number;
the first bottom blowing mechanism comprises N bottom blowing elements, the first bottom blowing mechanism is arranged on the circumference of an inscribed circle of the ellipse, and the center of the inscribed circle is located at the midpoint of the short axis of the ellipse.
Optionally, the included angle between the connecting line of each bottom blowing element in the first bottom blowing mechanism and the center of the circle and the long axis of the ellipse is 54-64 degrees.
Optionally, an included angle between a connecting line of each bottom blowing element in the second bottom blowing mechanism and the center of the circle and a long axis of the ellipse is 36-46 degrees.
Optionally, the first bottom blowing mechanism includes a first bottom blowing element, a second bottom blowing element, a third bottom blowing element, and a fourth bottom blowing element; the first bottom blowing elements and the second bottom blowing elements are axially symmetrically distributed relative to the short axis, the first bottom blowing elements and the fourth bottom blowing elements are axially symmetrically distributed relative to the long axis, and the second bottom blowing elements and the third bottom blowing elements are axially symmetrically distributed relative to the long axis;
the second bottom blowing mechanism comprises a fifth bottom blowing element, a sixth bottom blowing element, a seventh bottom blowing element and an eighth bottom blowing element; the fifth bottom blowing elements and the sixth bottom blowing elements are axially symmetrically distributed relative to the short axis, the fifth bottom blowing elements and the eighth bottom blowing elements are axially symmetrically distributed relative to the long axis, and the sixth bottom blowing elements and the seventh bottom blowing elements are axially symmetrically distributed relative to the long axis.
According to a second aspect, an embodiment of the present invention provides a control method for bottom blowing of a converter, which is applied to the converter provided in the first aspect, and includes:
and controlling N/2 bottom blowing elements in the first bottom blowing mechanism at the stage that the volume percentage of the top blowing oxygen supply of the converter is 70% -100%, wherein the N/2 bottom blowing elements in the second bottom blowing mechanism adopt a first total air supply flow to perform bottom blowing, and controlling the rest bottom blowing elements in the first bottom blowing mechanism and the second bottom blowing mechanism adopt a second total air supply flow to perform bottom blowing, wherein the first total air supply flow is more than twice the second total air supply flow.
In a third aspect, a control method for bottom blowing of a converter according to an embodiment of the present invention is applied to the converter provided in the first aspect, and the control method includes:
controlling the first bottom blowing group to perform bottom blowing by adopting a third total air supply flow rate and controlling the second bottom blowing group to perform bottom blowing by adopting a fourth total air supply flow rate in the stage that the volume percentage of the top blowing oxygen supply of the converter is 70-100%;
wherein the first bottom blowing group comprises the first bottom blowing element, the fourth bottom blowing element, the sixth bottom blowing element and the seventh bottom blowing element, or comprises the second bottom blowing element, the third bottom blowing element, the fifth bottom blowing element and the eighth bottom blowing element; the second bottom blowing group is the residual bottom blowing elements in the first bottom blowing mechanism and the second bottom blowing mechanism; the third total air supply flow rate is twice or more as large as the fourth total air supply flow rate.
Optionally, the third total air supply flow is 0.10-0.20M 3 The fourth total air supply flow is 0.010-0.040M 3 /min/t。
Optionally, the control method further includes:
controlling the first bottom blowing mechanism and the second bottom blowing mechanism to perform bottom blowing by adopting a fifth total air supply flow rate at the stage that the volume percentage of the top blowing oxygen supply of the converter is 0-20%, wherein the fifth total air supply flow rate is 0.08-0.20M 3 /min/t。
Optionally, the control method further includes:
controlling the first bottom blowing mechanism and the second bottom blowing mechanism to perform bottom blowing by adopting a sixth total air supply flow rate at a stage that the volume percentage of the top blowing oxygen supply of the converter is 20-70%, wherein the sixth total air supply flow rate is 0.03-0.08M 3 /min/t。
Optionally, at the stage that the volume percentage of the top-blown oxygen of the converter is 0% -70%, the air supply flow of each bottom blowing element in the first bottom blowing mechanism and the second bottom blowing mechanism is equal.
Through one or more technical schemes of the invention, the invention has the following beneficial effects or advantages:
the invention provides a converter, wherein a second bottom blowing mechanism is arranged on the circumference of an ellipse at the bottom of the converter, and a first bottom blowing mechanism is arranged on the circumference of an inscribed circle of the ellipse; the minor axis direction of the ellipse is the trunnion direction of the converter, the major axis direction is perpendicular to the trunnion direction, the major axis length of the ellipse is equal to the diameter of the converter bottom in the major axis direction or the diameter of the converter bottom in the minor axis direction, and the minor axis length is 60% -63% of the major axis length; the center of the inscribed circle is positioned at the midpoint of the short axis of the ellipse, and the diameter of the inscribed circle is equal to the length of the short axis. By arranging the plurality of bottom blowing elements in the first bottom blowing mechanism and the second bottom blowing mechanism in the mode, an asymmetric bottom blowing flow field can be formed at the bottom of the molten pool by controlling the blowing quantity and the air supply flow of the bottom blowing elements when bottom blowing is carried out, so that the carbon-oxygen area in molten steel is obviously reduced when the converter is tapped, and the smelting quality of the molten steel is improved.
The foregoing description is only an overview of the present invention, and is intended to be implemented in accordance with the teachings of the present invention in order that the same may be more clearly understood and to make the same and other objects, features and advantages of the present invention more readily apparent.
Drawings
Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to designate like parts throughout the figures.
In the drawings:
FIG. 1 shows a schematic view of a bottom blowing element arrangement of a converter hearth provided in accordance with the present invention;
fig. 2 shows a schematic diagram of the total air supply amount of the bottom blowing element according to embodiment 1 of the present invention;
FIG. 3 shows a bottom blowing element according to example 1 of the present invention using a large flow opening at a top blowing oxygen level of 70% to 100%(6) (7) schematic view of the position at the bottom of the furnace;
FIG. 4 shows a schematic representation of a method according to the inventionBottom blowing element of example 1(6) (7) a schematic diagram of the amount of air supplied during bottom blowing;
fig. 5 shows a bottom blowing element according to embodiment 1 of the present invention(5) (8) a schematic diagram of the amount of air supplied during bottom blowing;
FIG. 6 shows a bottom blowing element using a large flow opening at a top blowing oxygen supply of 70% to 100% according to example 2 of the present invention(5) (8) schematic view of the position at the bottom of the furnace.
Fig. 7 shows a bottom blowing element according to embodiment 2 of the present invention(5) (8) a schematic diagram of the amount of air supplied during bottom blowing;
fig. 8 shows a bottom blowing element according to embodiment 2 of the present invention(6) (7) schematic diagram of the air supply amount during bottom blowing.
Detailed Description
In order to make the technical solution more clearly understood by those skilled in the art, the following detailed description is made with reference to the accompanying drawings. Throughout the specification, unless specifically indicated otherwise, the terms used herein should be understood as meaning as commonly used in the art. Accordingly, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification will control. The various devices and the like used in the present invention are commercially available or can be prepared by existing methods unless otherwise specifically indicated.
At present, metallurgical workers also carry out a plurality of works in the aspect of improving the bottom blowing effect of the converter:
the related art 1 provides a bottom blowing process for controlling two groups of air bricks in a distributed manner on the same circle of a converter bottom blowing brick, which mainly comprises the steps of distributing the two groups of bottom blowing bricks according to different air volume ratios, ensuring that the bottom blowing bricks are not blocked by low air volume, and alternately opening the bottom blowing bricks in an opening mode, wherein the aim is to improve metallurgical reaction dynamics conditions and slow down corrosion to the bottom blowing bricks.
The related art 2 provides a method for arranging bottom blowing guns and a top-bottom combined blown converter, the patent designs the bottom blowing into N groups, each group at least comprises 2 bottom blowing guns with the same length, each two groups of bottom blowing guns in the N groups of bottom blowing guns are different in length, N is an integer not less than 2, the patent is used for optimizing and arranging to improve the steelmaking output of the converter, and a better metallurgical effect is realized, and the arranging mode is as follows: the bottom blowing guns are arranged on two concentric circles with different radiuses, the bottom blowing guns with different lengths are sequentially exposed along with the thinning of the low thickness of the furnace, so that the bottom blowing guns with different furnace ages are put into use, the bottom blowing guns can be operated in a designed mode, the bottom blowing guns can not be replaced in the whole operation period, normal production is not affected, and the phosphorus content of the end point of the converter can be controlled within 0.010% through the use of the scheme.
The related art 3 provides a method for improving the stirring effect of bottom-blown gas of a combined blown converter, wherein n nozzles for spraying the gas into the converter are arranged at the bottom of the converter, the n nozzles are distributed according to a spiral line, wherein the nozzle positioned at the center of the bottom of the converter is P1, each nozzle is P2, P3 and … … Pn in sequence from the center to the outside along the spiral line, the flow rate of the gas sprayed by each nozzle is Q1, Q2, Q3, Q4 and … … Qn in sequence, and the spraying flow rate of the nozzles is increased or decreased in sequence; the method aims at realizing spiral arrangement and different gas distribution of the bottom blowing elements of the converter, so that a molten pool flow field forms spiral stirring, further improving the stirring effect of the molten pool, and ensuring that the components and the temperature of molten steel are more uniform.
In order to solve the problem of optimizing the distribution pattern of the bottom blowing air bricks of the small top-bottom combined blowing converter, the related art 4 provides a mode of arranging three air bricks on the bottom of the converter, wherein the air bricks are arranged on concentric circumferences of 0.45D (D is the diameter of a molten pool), one air brick is arranged on a trunnion wire, and the other two air bricks are arranged on opposite sides, so that a non-uniform distribution structure is constructed. So as to shorten the mixing time of molten steel and improve the metallurgical effect.
The related art 5 provides a top-bottom combined blown converter air brick layout structure, which adopts four air bricks, the air bricks are arranged on two concentric circles with different diameters and are arranged in a rotationally symmetrical mode, the connecting line of the air bricks on the inner circumference and the trunnion is 21+/-5 degrees, and the connecting line of the air bricks on the outer circle and the trunnion is 15+/-5 degrees. The setting mode can strengthen the stirring of molten steel in a molten pool, shorten the mixing time, obviously reduce the TFe content in steel slag and reduce the total amount of initial inclusions by reasonably configuring the gas pressure and flow.
None of the above solutions provides its metallurgical effect in controlling the carbon oxygen product. Carbon oxygen accumulation is also called carbon oxygen concentration accumulation, and is an important index for measuring bottom blowing effect. The reduction of the carbon and oxygen accumulation at the end point of molten steel can improve the alloy yield and the molten steel quality. In order to further reduce the carbon oxygen volume of the molten steel end point of the furnace and improve the smelting quality, the application provides the following technical scheme.
In an alternative embodiment, a converter is provided that includes a first bottom blowing mechanism and a second bottom blowing mechanism;
the second bottom blowing mechanism comprises N bottom blowing elements, and is arranged on the circumference of the ellipse; the ellipse is positioned at the bottom of the converter and comprises a short shaft and a long shaft, the short shaft direction is the trunnion direction of the converter, and the long shaft direction is perpendicular to the trunnion direction; the length of the long shaft is equal to the diameter of the converter bottom in the long shaft direction or the diameter of the converter bottom in the short shaft direction, and the length of the short shaft is 60% -63% of the length of the long shaft; n is more than or equal to 4 and is an even number;
the first bottom blowing mechanism comprises N bottom blowing elements, and is arranged on the circumference of an inscribed circle of the ellipse, and the center of the inscribed circle is positioned at the midpoint of the short axis of the ellipse.
Specifically, the bottom blowing element may be a bottom blowing device commonly used in a converter such as a bottom blowing brick or a bottom blowing gun (nozzle).
In this embodiment, the ellipse is in the short axis direction with respect to the trunnion direction of the converter, and in the long axis direction with respect to the direction perpendicular to the trunnion. Regarding the major axis length of the ellipse, if the converter bottom is regarded as an ideal circle, the diameter length of the circle is the major axis length. In practice, however, the converter bottom is not the perfect ideal center, and the major axis length is determined based on the diameter of the converter bottom in the major axis direction or the diameter in the minor axis direction, for example, the shorter diameter of the two is determined as the major axis length of the ellipse. The length of the minor axis of the ellipse is determined based on the length of the major axis.
Intuitively, if the trunnion direction of the converter is defined as the Y-axis and the direction perpendicular to the trunnion is defined as the X-axis, the coordinate equation of the ellipse is:
wherein the length of the long axis is 2a, the length of the short axis is 2b, and b/a=0.60 to 0.63.
The center of the inscribed circle of the ellipse is the midpoint of the minor axis, and the minor axis of the ellipse is the diameter, and then the coordinate equation of the inscribed circle is:
x 2 +y 2 ＝b 2 (2)
the embodiment provides a converter, wherein a second bottom blowing mechanism is arranged on the circumference of an ellipse of the bottom of the converter, and a first bottom blowing mechanism is arranged on the circumference of an inscribed circle of the ellipse; the minor axis direction of the ellipse is the trunnion direction of the converter, the major axis direction is perpendicular to the trunnion direction, the major axis length of the ellipse is equal to the diameter of the converter bottom in the major axis direction or the diameter of the converter bottom in the minor axis direction, and the minor axis length is 60% -63% of the major axis length; the center of the inscribed circle is positioned at the midpoint of the short axis of the ellipse, and the diameter of the inscribed circle is equal to the length of the short axis. By arranging the plurality of bottom blowing elements in the first bottom blowing mechanism and the second bottom blowing mechanism in the mode, an asymmetric bottom blowing flow field can be formed at the bottom of the molten pool by controlling the blowing quantity and the air supply flow of the bottom blowing elements when bottom blowing is carried out, so that the carbon-oxygen area in molten steel is obviously reduced when the converter is tapped, and the smelting quality of the molten steel is improved.
Optionally, an included angle between a connecting line of each bottom blowing element and the center of the circle in the first bottom blowing mechanism and the long axis of the ellipse is 59±5°, namely 54 ° to 64 °, and an included angle between a connecting line of each bottom blowing element and the center of the circle in the second bottom blowing mechanism and the long axis of the ellipse is 41±5°, namely 36 ° to 46 °. Thus, the bottom blowing effect can be further improved.
For the sake of illustration, fig. 1 shows a schematic illustration of the arrangement of bottom blowing elements of a converter bottom, the first bottom blowing mechanism comprising 4 bottom blowing elements: first bottom blowing elementSecond bottom blowing element->Third bottom blowing element->And a fourth bottom blowing elementFirst bottom blowing element->And a second bottom blowing element->Is axisymmetrically distributed relative to the short axis, the first bottom blowing element +.>And a fourth bottom blowing element->Is axisymmetrically distributed relative to the long axis, and the second bottom blowing element is +>And a third bottom blowing element->Is axisymmetrically distributed relative to the long axis; when the above conditions are met, a third bottom blowing element +.>And a fourth bottom blowing element->Is axisymmetrically distributed relative to the short axis.
The second bottom blowing mechanism also includes 4 bottom blowing elements: a fifth bottom blowing element (5), a sixth bottom blowing element (6), a seventh bottom blowing element (7), an eighth bottom blowing element (8); the fifth bottom blowing element (5) and the sixth bottom blowing element (6) are axially symmetrically distributed relative to the short axis, the fifth bottom blowing element (5) and the eighth bottom blowing element (8) are axially symmetrically distributed relative to the long axis, and the sixth bottom blowing element (6) and the seventh bottom blowing element (7) are axially symmetrically distributed relative to the long axis; when the conditions are met, the seventh bottom blowing element (7) and the eighth bottom blowing element (8) are axisymmetrically distributed relative to the short axis.
FIG. 1 also shows a first bottom blowing elementAnd an included angle alpha between the center connecting line of the inscribed circles and the X axis (the long axis of the ellipse), and an included angle beta between the center connecting line of the seventh bottom blowing element (7) and the inscribed circles and the X axis. Due to the aforementioned symmetry, the second bottom blowing element +.>Third bottom blowing element->And a fourth bottom blowing element->The corresponding included angle between the bottom blowing element and the X axis is alpha, the bottom blowing element (5) is fifth, the bottom blowing element (6) is sixth, and the corresponding included angle between the bottom blowing element (8) and the X axis is beta.
It should be noted that the included angles are acute angles, and are independent of the direction of the X axis.
Based on the converter provided in the foregoing embodiment, in another optional embodiment, a method for controlling bottom blowing of a converter is provided, which specifically includes the following steps:
in the stage that the volume percentage of the top-blown oxygen of the converter is 70% -100%, controlling N/2 bottom blowing elements in the first bottom blowing mechanism, wherein N/2 bottom blowing elements in the second bottom blowing mechanism adopt a first total air supply flow to perform bottom blowing, and controlling the rest bottom blowing elements in the first bottom blowing mechanism and the second bottom blowing mechanism adopt a second total air supply flow to perform bottom blowing, wherein the first total air supply flow is more than twice the second total air supply flow.
Specifically, after molten iron is added into the converter, the period from the beginning of converting to the end of converting can be measured by taking the volume percentage of top-blown oxygen as a parameter. When the top-blown oxygen supply amount is 0%, the start of converting is indicated, and when the top-blown oxygen supply amount is 100%, the end of converting is indicated. The total air supply flow represents the sum of the air blowing amounts of the corresponding bottom blowing elements.
The scheme provided by the embodiment is that the bottom blowing element is opened in a non-uniform and high-flow mode at 70% -100% stage of top blowing oxygen. Specifically, half of bottom blowing elements in the first bottom blowing mechanism and half of bottom blowing elements in the second bottom blowing mechanism are opened by adopting larger flow, and the rest of bottom blowing elements are opened by adopting smaller flow. By opening the bottom blowing element in a non-uniform and large-flow mode, an asymmetric bottom blowing flow field can be formed at the bottom of the molten pool, so that the carbon-oxygen area of molten steel is rapidly reduced, and the smelting effect is improved.
Taking the example that the first bottom blowing mechanism and the second bottom blowing mechanism in the foregoing embodiment are each configured with 4 bottom blowing elements, the bottom blowing scheme is as follows:
controlling the first bottom blowing group to perform bottom blowing by adopting a third total air supply flow rate and controlling the second bottom blowing group to perform bottom blowing by adopting a fourth total air supply flow rate in the stage that the volume percentage of the top blowing oxygen supply of the converter is 70-100%; the third total air supply flow rate is twice or more as high as the fourth total air supply flow rate.
The preferred mode of the first bottom blowing group and the second bottom blowing group is asymmetric, and specifically comprises the following steps:
the first bottom blowing group opened at the third total supply air flow rate (large flow rate) includes:
first bottom blowing elementFourth bottom blowing element->A sixth bottom blowing element (6) and a seventh bottom blowing element (7);
the second bottom blowing group opened at the fourth total supply air flow rate (small flow rate) includes:
second bottom blowing elementThird bottom blowing element->A fifth bottom blowing element (5) and an eighth bottom blowing element (8).
Or both exchanges, i.e.:
the bottom blowing element that is opened at the third total air supply flow rate has:⑤⑧；
the bottom blowing element that is opened at the fourth total air supply flow rate has:⑥⑦。
opening at a high flow rate(6) (7) Small flow En->(5) (8) as an example, optionally, < >>(6) (7) the third total air supply flow rate is 0.10-0.20M 3 Per min/t (unit: cubic meter/min/ton); />(5) (8) the fourth total air supply flow rate of the opened air supply is 0.010 to 0.040M 3 /min/t. The blowing amount of each bottom blowing element can be the same or slightly different.
In addition, in the stage that the volume percentage of the top-blown oxygen of the converter is 0% -20%, the first bottom blowing mechanism and the second bottom blowing mechanism can be controlled according to the following steps: 0.08 to 0.20M 3 The total air supply flow per minute/t is used for blowing. At this stage, the bottom blowing elements are all opened, and the blowing amount of each bottom blowing element can be equally distributed.
In the stage that the volume percentage of the top-blown oxygen of the converter is 20% -70%, the first bottom blowing mechanism and the second bottom blowing mechanism are controlled according to the following steps: 0.03 to 0.08M 3 The total air supply flow per minute/t is used for blowing. Compared with 0 to 20 percent of the stage, the total bottom blowing gas supply intensity is reduced in the stage, so that the decarburization speed of a molten pool is reduced, the oxygen content in steel is accumulated, further rapid slag melting is realized, and thermodynamic conditions are provided for dephosphorization.
On the other hand, other alternatives of the first bottom blowing group and the second bottom blowing group are:
the bottom blowing element that is opened at the third total air supply flow rate has:⑦⑧；
the bottom blowing element that is opened at the fourth total air supply flow rate has:⑤⑥。
or:
the bottom blowing element that is opened at the third total air supply flow rate has:⑥⑧；
the bottom blowing element that is opened at the fourth total air supply flow rate has:⑤⑦。
in order to more intuitively illustrate the above-described scheme, the following description is made in connection with specific implementation data.
Example 1:
for a certain steel mill No. 1 converter (200 t), when the furnace bottom is built, firstly determining the position of a central brick, then carrying out combined building of the bottom brick and an air brick, and selecting a bottom blowing position; b/a takes the value of 0.62, alpha=62°, beta=38°, and the rest of bottom blowing elements are respectively positioned at the positions corresponding to the symmetrical points of the x axis and the y axis of the two points, and total 8 bottom blowing elements are arranged. After all preparation works before preparing smelting are finished, selecting the smelting steel grade as 9Ni steel, wherein the flow and the gun position of a top blowing oxygen gun in the blowing process are the same as or similar to those of the conventional smelting process, and the top blowing air supply intensity is 3.0-3.8M 3 And (3) between/min/t, gun position and flow rate changing operation is performed in the process. The total air supply flow of the bottom blowing element in the smelting process is shown in figure 2.
The total air supply intensity of all the bottom blowing elements at the beginning of converting is 0.2M 3 First bottom blowing group/min/t(6) (7) and a second bottom blowing group->(5) (8) all use 0.10M 3 Bottom blowing air supply intensity/min/t;
after converting to 20% of top-blown oxygen, the total air supply intensity of bottom blowing is adjusted to 0.08M 3 The air supply quantity of each bottom blowing element is evenly distributed, and the total bottom blowing air supply intensity is reduced at the stage to reduce the decarburization speed of a molten pool, accumulate the oxygen content in steel, realize further rapid slag melting and provide thermodynamic bars for dephosphorization;
when converting to 70% of top blowing oxygen supply, adjusting bottom blowing air supply mode as in figure 3, and starting at high flow rate(6) (7) the bottom blowing strength value is set to the upper limit value as shown in FIG. 4, bottom blowing element +.>(6) (7) Total air supply intensity value is 0.12M 3 The air supply quantity of each branch is evenly distributed per minute/t;
bottom blowing element(5) (8) the flow is shown in figure 5, and when the total amount of the top blowing of the converter is 0-20%, 20-70% and 70-100%, the flow is +.>(5) (8) total air supply intensities of 0.10M respectively 3 /min/t、0.040M 3 /min/t、0.036M 3 /min/t，(5) (8) the air supply amount of each bottom blowing member is equally distributed.
After the converter smelting is completed, a converter end point steel sample is taken for component analysis, and the results are shown in table 1:
table 1: example 1 converter endpoint composition, temperature, and carbon oxygen control
Example 2:
for a 3# converter (200 t) of the same steel plant, when the furnace bottom is built, the position of a central brick is firstly determined, then the combination building of the bottom brick and an air brick is carried out, and the bottom blowing position is selected, wherein the b/a value is 0.62, alpha=55 DEG, beta=43 DEG, and the rest bottom blowing elements are respectively positioned at the positions of the two points corresponding to the symmetry points of the x axis and the y axis, so that the total number of the bottom blowing elements is 8. After all preparation works before preparing smelting are finished, blowing is started, the smelting steel grade is selected to be 9Ni steel, and the blowing process is performedThe flow and the gun position of the oxygen lance are similar to those of the conventional smelting, and the top blowing air supply strength is 3.0-3.8M 3 And/min/t, and gun position changing operation is performed in the process. The total air supply flow of the bottom blowing element in the smelting process is shown in figure 2.
When converting is started, a first bottom blowing group(5) (8) and a second bottom blowing group->(6) The total air supply intensity of (7) is 0.1M 3 /min/t；
After converting to 20% of top-blown oxygen, the total air supply intensity of bottom blowing is adjusted to 0.04M 3 The air supply quantity of each bottom blowing element is evenly distributed, the total bottom blowing air supply intensity is reduced at the stage to reduce the decarburization speed of a molten pool, the oxygen content in steel is accumulated, further rapid deslagging is realized, and thermodynamic conditions are provided for dephosphorization;
when converting to 70% of top-blown oxygen, the bottom-blown air supply mode was adjusted as shown in FIG. 6(5) (8) high flow bottom blowing, the bottom blowing strength value is shown in FIG. 7, and the total air supply strength value is 0.12M 3 Per minute/t, each branch of gas is distributed evenly;
remaining bottom blowing element(6) The flow rate is shown in figure 8, and when the total amount of the top blowing of the converter is 0-20%, 20-70%, 70-100%>(6) (7) total air supply intensities of 0.10M respectively 3 /min/t、0.040M 3 /min/t、0.036M 3 /min/t, wherein->(6) (7) the air supply amount of the bottom blowing member is equally distributed.
After the converter smelting is completed, a converter end point steel sample is taken for component analysis, and the results are shown in table 2:
table 2: example 2 converter endpoint composition, temperature, and carbon oxygen control
Comparative example:
for a certain steel mill No. 1 converter (200 t), the original conventional bottom blowing element arrangement is adopted when the bottom of the converter is built, and the blowing amount of the bottom blowing elements also adopts the original conventional configuration scheme.
The composition data of the historical converter end point of the 9Ni steel smelted in the 1# converter were counted, and the results are shown in table 3:
table 3: comparative converter endpoint composition, temperature, and carbon oxygen control
As can be seen from the composition data of the comparative example and the example, after the arrangement scheme of the converter and the bottom blowing element provided by the invention is adopted, the carbon-oxygen area in molten steel is obviously reduced, the contents of phosphorus P and sulfur S are also obviously reduced, and the smelting effect is improved.
Through one or more embodiments of the present invention, the present invention has the following benefits or advantages:
the invention provides a converter, wherein a second bottom blowing mechanism is arranged on the circumference of an ellipse at the bottom of the converter, and a first bottom blowing mechanism is arranged on the circumference of an inscribed circle of the ellipse; the minor axis direction of the ellipse is the trunnion direction of the converter, the major axis direction is perpendicular to the trunnion direction, the major axis length of the ellipse is equal to the diameter of the converter bottom in the major axis direction or the diameter of the converter bottom in the minor axis direction, and the minor axis length is 60% -63% of the major axis length; the center of the inscribed circle is positioned at the midpoint of the short axis of the ellipse, and the diameter of the inscribed circle is equal to the length of the short axis. By arranging the plurality of bottom blowing elements in the first bottom blowing mechanism and the second bottom blowing mechanism in the mode, an asymmetric bottom blowing flow field can be formed at the bottom of the molten pool by controlling the blowing quantity and the air supply flow of the bottom blowing elements when bottom blowing is carried out, so that the carbon-oxygen area in molten steel is obviously reduced when the converter is tapped, and the smelting quality of the molten steel is improved.
While the preferred embodiments of the present application have been described, additional variations and modifications in those embodiments may occur to those skilled in the art once they learn of the basic inventive concepts. It is therefore intended that the following claims be interpreted as including the preferred embodiments and all such alterations and modifications as fall within the scope of the application.
It will be apparent to those skilled in the art that various modifications and variations can be made in the present application without departing from the spirit or scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims and the equivalents thereof, the present application is intended to cover such modifications and variations.
Claims (8)
1. A converter, characterized in that the converter comprises a first bottom blowing mechanism and a second bottom blowing mechanism;
the second bottom blowing mechanism comprises N bottom blowing elements, and is arranged on the circumference of the ellipse; the ellipse is positioned at the bottom of the converter and comprises a short shaft and a long shaft, the short shaft direction is the trunnion direction of the converter, and the long shaft direction is perpendicular to the trunnion direction; the length of the long shaft is equal to the diameter of the converter bottom in the long shaft direction or the diameter of the converter bottom in the short shaft direction, and the length of the short shaft is 60% -63% of the length of the long shaft; n is more than or equal to 4 and is an even number; the first bottom blowing mechanism comprises N bottom blowing elements, the first bottom blowing mechanism is arranged on the circumference of an inscribed circle of the ellipse, and the center of the inscribed circle is positioned at the midpoint of the short axis of the ellipse;
the included angle between the connecting line of each bottom blowing element in the first bottom blowing mechanism and the circle center and the long axis of the ellipse is 54-64 degrees; and an included angle between a connecting line of each bottom blowing element in the second bottom blowing mechanism and the center of the circle and the long axis of the ellipse is 36-46 degrees.
2. The converter of claim 1, wherein the first bottom blowing mechanism comprises a first bottom blowing element, a second bottom blowing element, a third bottom blowing element, and a fourth bottom blowing element; the first bottom blowing elements and the second bottom blowing elements are axially symmetrically distributed relative to the short axis, the first bottom blowing elements and the fourth bottom blowing elements are axially symmetrically distributed relative to the long axis, and the second bottom blowing elements and the third bottom blowing elements are axially symmetrically distributed relative to the long axis;
the second bottom blowing mechanism comprises a fifth bottom blowing element, a sixth bottom blowing element, a seventh bottom blowing element and an eighth bottom blowing element; the fifth bottom blowing elements and the sixth bottom blowing elements are axially symmetrically distributed relative to the short axis, the fifth bottom blowing elements and the eighth bottom blowing elements are axially symmetrically distributed relative to the long axis, and the sixth bottom blowing elements and the seventh bottom blowing elements are axially symmetrically distributed relative to the long axis.
3. A control method of converter bottom blowing, characterized by being applied to the converter according to claim 1, the control method comprising:
and controlling N/2 bottom blowing elements in the first bottom blowing mechanism at the stage that the volume percentage of the top blowing oxygen supply of the converter is 70% -100%, wherein N/2 bottom blowing elements in the second bottom blowing mechanism adopt a first total air supply flow to perform bottom blowing, and controlling the rest bottom blowing elements in the first bottom blowing mechanism and the second bottom blowing mechanism adopt a second total air supply flow to perform bottom blowing, wherein the first total air supply flow is more than twice the second total air supply flow.
4. A control method of converter bottom blowing, characterized by being applied to a converter as claimed in claim 2, the control method comprising:
controlling the first bottom blowing group to perform bottom blowing by adopting a third total air supply flow rate and controlling the second bottom blowing group to perform bottom blowing by adopting a fourth total air supply flow rate in the stage that the volume percentage of the top blowing oxygen supply of the converter is 70% -100%;
wherein the first bottom blowing group comprises the first bottom blowing element, the fourth bottom blowing element, the sixth bottom blowing element and the seventh bottom blowing element, or comprises the second bottom blowing element, the third bottom blowing element, the fifth bottom blowing element and the eighth bottom blowing element; the second bottom blowing group is the residual bottom blowing elements in the first bottom blowing mechanism and the second bottom blowing mechanism; the third total air supply flow rate is twice or more as large as the fourth total air supply flow rate.
5. The control method according to claim 4, wherein the third total air supply flow rate is 0.10 to 0.20M 3 The fourth total air supply flow is 0.010-0.040M 3 /min/t。
6. The control method as set forth in claim 4, further comprising:
controlling the first bottom blowing mechanism and the second bottom blowing mechanism to perform bottom blowing by adopting a fifth total air supply flow at a stage that the volume percentage of the top blowing oxygen supply of the converter is 0% -20%, wherein the fifth total air supply flow is 0.08-0.20M 3 /min/t。
7. The control method as set forth in claim 4, further comprising:
controlling the first bottom blowing mechanism and the second bottom blowing mechanism to perform bottom blowing by adopting a sixth total air supply flow rate at a stage that the volume percentage of the top blowing oxygen supply of the converter is 20% -70%, wherein the sixth total air supply flow rate is 0.03-0.08M 3 /min/t。
8. The control method according to claim 6 or 7, wherein the air supply flow rate of each bottom blowing element in the first bottom blowing mechanism and the second bottom blowing mechanism is equal at a stage where the volume percentage of the top blowing oxygen of the converter is 0% -70%.
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| CN2908521Y (en) * | 2006-04-29 | 2007-06-06 | 宝山钢铁股份有限公司 | Inclined hole type air brick for bottom-blowing of converter |
| CN201176446Y (en) * | 2008-04-09 | 2009-01-07 | 唐山建龙实业有限公司 | Bottom bowing layout structure for medium top-bottom combined blown converter |
| CN203602649U (en) * | 2013-11-29 | 2014-05-21 | 武汉钢铁(集团)公司 | Bottom blowing structure for small-sized smelting container |
| CN104099442A (en) * | 2014-07-16 | 2014-10-15 | 首钢总公司 | Arrangement method for bottom blowing guns of converter and top-bottom combined blowing converter |
| JP2016027201A (en) * | 2014-06-30 | 2016-02-18 | Ｊｆｅスチール株式会社 | Bottom-blown tuyere block for converter |
| JP2016199788A (en) * | 2015-04-10 | 2016-12-01 | Ｊｆｅスチール株式会社 | Bottom-blown tuyere for converter |
| CN113957203A (en) * | 2021-12-21 | 2022-01-21 | 太原科技大学 | Multifunctional non-centrosymmetric vacuum refining equipment |
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2022
- 2022-09-30 CN CN202211209382.XA patent/CN115637307B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN2908521Y (en) * | 2006-04-29 | 2007-06-06 | 宝山钢铁股份有限公司 | Inclined hole type air brick for bottom-blowing of converter |
| CN201176446Y (en) * | 2008-04-09 | 2009-01-07 | 唐山建龙实业有限公司 | Bottom bowing layout structure for medium top-bottom combined blown converter |
| CN203602649U (en) * | 2013-11-29 | 2014-05-21 | 武汉钢铁(集团)公司 | Bottom blowing structure for small-sized smelting container |
| JP2016027201A (en) * | 2014-06-30 | 2016-02-18 | Ｊｆｅスチール株式会社 | Bottom-blown tuyere block for converter |
| CN104099442A (en) * | 2014-07-16 | 2014-10-15 | 首钢总公司 | Arrangement method for bottom blowing guns of converter and top-bottom combined blowing converter |
| JP2016199788A (en) * | 2015-04-10 | 2016-12-01 | Ｊｆｅスチール株式会社 | Bottom-blown tuyere for converter |
| CN113957203A (en) * | 2021-12-21 | 2022-01-21 | 太原科技大学 | Multifunctional non-centrosymmetric vacuum refining equipment |
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