CN111944942B - Dynamic tapping control method and device for eccentric furnace bottom of converter - Google Patents
Dynamic tapping control method and device for eccentric furnace bottom of converter Download PDFInfo
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- CN111944942B CN111944942B CN202010751785.1A CN202010751785A CN111944942B CN 111944942 B CN111944942 B CN 111944942B CN 202010751785 A CN202010751785 A CN 202010751785A CN 111944942 B CN111944942 B CN 111944942B
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
- C21C5/28—Manufacture of steel in the converter
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
- C21C5/28—Manufacture of steel in the converter
- C21C5/42—Constructional features of converters
- C21C5/46—Details or accessories
- C21C5/4653—Tapholes; Opening or plugging thereof
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Abstract
The invention provides a dynamic tapping control method and a dynamic tapping control device for an eccentric furnace bottom of a converter, relates to the technical field of metallurgy, can solve the problems of large slag discharge amount and gas suction and secondary oxidation of molten steel in the existing tapping scheme, realizes quick and protective tapping, and is convenient for providing purer molten steel for the next production procedure; the method comprises the following steps: s1, after the converter finishes converting, rotating the furnace body to rotate the steel tapping hole to the lowest position; the tapping hole is arranged in the eccentric area of the furnace and avoids the low-blowing area; s2, reading smelting data and component data, and calculating the opening size of the steel notch drift diameter; s3, mounting a protective sleeve at the steel tapping hole and positioning a steel ladle; s4, opening a steel tapping hole, and tapping in protective atmosphere; s5, closing the steel tapping hole when the liquid level of molten steel in the converter is reduced to a preset height; s6, slag splashing and furnace protection, and tapping is finished; the ladle is a lifting ladle, and a protective atmosphere bottom blowing structure is arranged in the ladle. The technical scheme provided by the invention is suitable for the smelting and tapping process.
Description
[ technical field ] A method for producing a semiconductor device
The invention relates to the technical field of metallurgy, in particular to a method and a device for controlling dynamic tapping at an eccentric furnace bottom of a converter.
[ background of the invention ]
At present, a converter adopts a trough type tapping mode, and a tapping hole is arranged at the junction of a furnace cap and a furnace body. In order to reduce the slag discharge during tapping, most of the existing converters adopt a mode of adding a slag blocking device in the tapping process to reduce the slag discharge. When the molten steel is smelted and ready for tapping, the ladle car is moved to a tapping position, the converter is rotated to tap, when 30% -50% of the total amount of the residual molten steel in the converter is molten, the slag blocking rod is added, and when the molten steel is discharged, the converter is tilted and rotated to-40-20 degrees, the slag blocking cap is added. After the measures are taken, the slag discharging amount of the converter tapping is reduced, but in the converter swinging process, the phenomenon that the slag blocking cap is not tightly sintered and slides off frequently occurs due to the fact that the angle of the swinging furnace is large (0-100 degrees), and a large amount of slag is discharged. And the angle of the furnace is large, so that the precise matching of the ladle car and the converter is required, and the operation difficulty is large. In addition, the position of the steel tapping hole is high, so that the exposure time of the molten steel in the air is too long in the steel tapping process, the temperature drop is large, and secondary oxidation of the molten steel is easily caused.
With the increasing requirements of users on the quality of steel, the quality of molten steel needs to be improved continuously. Reducing the amount of slag discharged during tapping of the converter is an important aspect of improving the quality of molten steel. The slag discharge is reduced in the converter tapping process, so that the rephosphorization of the molten steel can be reduced, the alloy yield is improved, the inclusion in the steel can be reduced, the cleanliness of the molten steel is improved, the slag adhesion of a steel ladle can be reduced, and the service life of the steel ladle is prolonged. Meanwhile, the consumption of refractory materials can be reduced, the service life of the refractory materials at the steel tapping hole of the converter is correspondingly prolonged, and good conditions can be provided for refining molten steel.
Therefore, there is a need to develop a method and an apparatus for controlling dynamic tapping at an eccentric bottom of a converter, which can overcome the shortcomings of the prior art and solve or alleviate one or more of the above problems.
[ summary of the invention ]
In view of the above, the invention provides a method and a device for controlling dynamic tapping at an eccentric furnace bottom of a converter, which can solve the problems of large slag dropping amount and gas suction and secondary oxidation of molten steel in the existing tapping scheme, realize quick and protected tapping, and facilitate the provision of purer molten steel for the next production process.
In one aspect, the invention provides a dynamic tapping control method for an eccentric furnace bottom of a converter, which is characterized by comprising the following steps:
s1, after the converter finishes converting, rotating the furnace body to rotate the steel tapping hole to the lowest position; the tapping hole is arranged in the eccentric area of the furnace and avoids the low-blowing area;
s2, determining the opening size of the drift diameter of the steel tapping hole based on temperature control;
the process of determining the opening size of the drift diameter of the steel tapping hole based on temperature control comprises the following steps: obtaining ideal tapping time and tapping flow according to the target tapping temperature, the ideal temperature reaching the ladle and the temperature drop rate information, and further determining the opening size of the steel hole drift diameter;
s3, mounting a protective sleeve at the steel tapping hole and positioning a steel ladle;
s4, opening the steel tapping hole according to the result of S2, and tapping in a protective atmosphere;
s5, closing the steel tapping hole when the liquid level of molten steel in the converter is reduced to a preset height, and straightening the converter body;
and S6, slag splashing and furnace protection, and tapping is finished.
As for the above-mentioned aspect and any possible implementation manner, there is further provided an implementation manner, and the specific content of step S5 includes: and when the liquid level of the molten steel is reduced to 5% of the original height, the drift diameter of the steel outlet is gradually reduced, and when the liquid level of the molten steel is reduced to 1% -2% of the original height, the steel outlet is completely closed.
The above aspects and any possible implementation manners further provide an implementation manner that the ladle adopts a lifting ladle car, and the height of the ladle is dynamically adjusted according to actual conditions in the tapping process, so that the protective sleeve is prevented from contacting molten steel in the ladle.
The above aspects and any possible implementation manners further provide an implementation manner, an argon bottom-blowing valve is arranged in the steel ladle, and the argon bottom-blowing valve is opened before tapping to exhaust air in the steel ladle, so that atmosphere protection tapping is realized.
The above aspects and any possible implementations further provide an implementation in which the tap hole is provided at 3/4 of the radius of the cross section of the bottom segment spherical segment body; the included angle between the steel tapping hole and the vertical direction ranges from 30 degrees to 40 degrees, and the distance between the steel tapping hole and the edge of the furnace bottom ranges from 0.375m to 0.75 m.
The above aspect and any possible implementation manner further provide an implementation manner, and the calculation manner of the molten steel liquid level height is as follows: a first microwave sensor is arranged above the furnace mouth for measuring the vertical distance H between the first microwave sensor and the liquid level of the slag2Meanwhile, a second microwave sensor is arranged at the steel tapping hole for measuring the vertical distance H between the two microwave sensors3Calculating the slag thickness H from the data read in step S21When the height H of molten steel surface is equal to H3-H2-H1。
The above aspects and any possible implementations further provide an implementation in which the first microwave sensor is further configured to measure a radius of the slag level in real time, including a major axis and a minor axis, for calculating a slag level area; thickness H of slag1The volume of slag V/slag level area S.
On the other hand, the invention provides a dynamic tapping control device for an eccentric furnace bottom of a converter, which comprises the eccentric furnace of the converter and a ladle and is characterized in that a tapping hole of the eccentric furnace of the converter is arranged in an eccentric area and avoids a low-blowing area; the opening size of the drift diameter of the steel tapping hole is adjustable based on temperature control; a protective sleeve is arranged at the steel tapping hole; the steel ladle is a lifting type steel ladle, and the height of the steel ladle can be adjusted in the tapping process; and a protective atmosphere bottom blowing structure is arranged in the steel ladle and used for realizing protective tapping.
The above aspect and any possible implementation further provide an implementation in which the protective sleeve has a three-layer layered structure; a working layer built by refractory bricks, a heat insulation layer and an iron outer shell layer from inside to outside.
The above aspects and any possible implementations further provide an implementation in which the tap hole is provided at 3/4 of the radius of the cross section of the bottom segment spherical segment; the included angle between the steel tapping hole and the vertical direction ranges from 30 degrees to 40 degrees, and the distance between the steel tapping hole and the edge of the furnace bottom ranges from 0.375m to 0.75 m.
The above aspects and any possible implementation manners further provide an implementation manner, wherein a first microwave sensor is arranged above a furnace opening of the converter eccentric furnace and used for measuring the vertical height of the slag liquid level and the diameter of the slag liquid level in real time; and a second microwave sensor is arranged at the steel tapping hole and used for measuring the vertical distance between the two microwave sensors in real time.
Compared with the prior art, the invention can obtain the following technical effects: the tapping hole is arranged at the bottom of the furnace, and steel is rapidly tapped by virtue of the pressure of purified water of molten steel; the molten steel liquid level height calculation formula can accurately display the position of the slag and make an accurate prompt for an operator to close the steel outlet; the steel tapping hole drift diameter calculation formula can flexibly deal with molten steel under different end point conditions, and the converter can realize quick and stable steel tapping; the furnace thickness monitoring system and the dynamic steel tapping hole are matched to realize less slag tapping and even zero slag tapping; the steel tapping protective sleeve isolates molten steel from air, so that the suction and secondary oxidation of the molten steel can be avoided; the novel process for tapping at the eccentric furnace bottom of the converter can reduce tapping time by 30-50%, lower slag amount by less than 5%, and the gas suction and secondary oxidation amount of molten steel close to 0%, thereby not only improving working efficiency, but also providing purer molten steel for the next procedure.
Of course, it is not necessary for any one product in which the invention is practiced to achieve all of the above-described technical effects simultaneously.
[ description of the drawings ]
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
FIG. 1 is a flow chart of tapping from an eccentric bottom of a converter according to an embodiment of the present invention;
FIG. 2 is a view illustrating a position of a tap hole of an eccentric furnace of the converter according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of a system for displaying the level of molten steel in real time according to an embodiment of the present invention;
FIG. 4 is a schematic view of an adjustable tap hole structure provided in an embodiment of the present invention;
fig. 5 is a block diagram of a protective sleeve provided in accordance with an embodiment of the present invention;
FIG. 6 is a schematic structural view of an elevating buggy ladle according to an embodiment of the present invention;
FIG. 7 is a schematic drawing of the tapping flow provided by an embodiment of the present invention.
[ detailed description ] embodiments
For better understanding of the technical solutions of the present invention, the following detailed descriptions of the embodiments of the present invention are provided with reference to the accompanying drawings.
It should be understood that the described embodiments are only some embodiments of the invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The terminology used in the embodiments of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used in the examples of the present invention and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.
The specific process of the dynamic tapping control method for the eccentric furnace bottom of the converter provided by the invention can be described as follows: after the converter blowing is finished, the furnace body is rotated to rotate the steel outlet to the lowest position, steel is ready to be tapped, the current smelting furnace charging condition including molten iron, waste steel, lime, dolomite (light burned dolomite and raw dolomite), ore charging amount and component information thereof are obtained from the database, and key TSO molten steel detection information and slag component information are obtained. And then calculating the mass of the slag based on the material balance, and calculating the density of the current slag based on a semi-empirical formula of the density of the slag to obtain the volume of the slag. The height from the slag to the liquid level of the slag and the distance between the long axis and the short axis of the elliptical surface of the slag are measured by the microwave sensor 1, the surface area of the slag is calculated, and the thickness of the slag is obtained. The microwave sensor 2 and the steel tapping hole are on the same horizontal line, and are responsible for measuring the vertical distance between the microwave sensor and the sensor 1 and calibrating to obtain the height of the molten steel.
Meanwhile, the TSO temperature (namely the target tapping temperature) of the molten steel, the ideal temperature reaching the ladle and the temperature drop rate information are comprehensively considered, the ideal tapping time and the ideal tapping flow are calculated, the size of the open drift diameter of the tapping hole is further calculated, the opening of the tapping hole can be flexibly adjusted, and the tapping rhythm is controlled.
And then, a magnesium protective sleeve is installed at the steel tapping hole, the lifting type ladle car is driven to a position right below the steel tapping hole, argon bottom blowing is started, the height of the ladle is lifted by virtue of a lifter, the protective sleeve is immersed into the steel tapping hole for 0.5m, then the steel tapping hole is opened, rapid steel tapping is protected, the height of the ladle is slowly reduced along with the rise of the liquid level of molten steel in the ladle, and the protective sleeve is prevented from being in contact with the molten steel.
The control method comprises the following specific steps:
based on the position of the tap hole of the large and medium converters; arranging a converter steel tapping hole in a furnace eccentric area to avoid a bottom blowing area;
acquiring smelting data and raw and auxiliary material component information;
a molten steel liquid level real-time monitoring system established based on smelting data is used for calibrating and calculating the slag thickness and the molten steel liquid level height in real time;
calculating the size of the open and close drift diameter of a steel opening based on a smelting temperature control principle
Based on the consideration of preventing the suction and the secondary oxidation of the molten steel, a magnesium protective sleeve is additionally arranged at the steel outlet;
based on the consideration of protection tapping, the height of the ladle is dynamically adjusted by adopting a lifting ladle car.
In order to complete the operation process, the invention provides the following technical scheme:
(1) design of tap hole
For large and medium-sized converters, the molten pool is composed of a segment body and a cylinder, and in the blowing process, in order to ensure the kinetics of the reaction in the molten pool, a bottom blowing hole is usually arranged at the bottom of the converter. Therefore, when the position of the bottom tap hole is designed, the bottom blowing area of the converter is avoided. The position of the steel tapping hole is designed as shown in the attached figure 2.
The bottom of large and medium-sized converters is provided with a bottom blowing zone, and generally, 8 bottom blowing holes are uniformly distributed on the circumference of the bottom blowing zone. The position of the steel tapping hole deviates from a bottom blowing area of the converter, the steel tapping hole cannot be too close to the bottom blowing area, gas-liquid two-phase flow is prevented from being severe, the steel tapping hole is seriously scoured and eroded, the steel tapping hole cannot be too close to the edge of the furnace bottom, the included angle between the steel tapping hole and the vertical direction is larger due to the fact that the steel tapping hole is closer to the edge of the furnace bottom, the furnace shaking angle is larger when steel tapping is caused, and operation difficulty is increased. Wherein the included angle between the steel tapping hole and the vertical direction is 30-40 degrees, and the distance between the steel tapping hole and the edge of the furnace bottom is controlled within the range of 0.375-0.75 m. Through analysis, the steel tapping hole is best installed at the position 3/4 of the radius of the section of the spherical segment body of the furnace bottom.
The angle of the steel tapping hole is vertical to the cambered surface of the segment body along the radius direction of the segment body. In the smelting process, the arc surface of the furnace bottom is used as a supporting surface to bear all gravity from molten steel and steel slag, the direction of the supporting force of the arc surface is vertical to the arc surface and points to the center of a sphere, and the steel outlet is arranged along the radius direction, so that the steel outlet is uniformly stressed and is not easy to deform, and the maintenance is convenient. The calculation method of the size of the steel tapping hole is consistent with the design of the traditional converter, and the calculation formula of the diameter of the steel tapping hole is as follows:
in the formula: g represents the nominal capacity of the converter.
(2) Molten steel liquid level real-time monitoring system
Firstly, the current heat is called to obtain smelting data, the molten iron adding amount, the molten iron components, the molten iron temperature, the TSO components and temperature information, and slagging materials such as lime, dolomite and ore, and the like, so as to obtain the adding amount and the component data information, and the specific data are shown in tables 1 to 3.
TABLE 1 addition of raw and auxiliary materials
TABLE 2 composition parameters of the metal charge
TABLE 3 slag-forming material composition parameters
TABLE 4 slag composition test
The slag is from oxidation products of each element in the metal material, the flux and the erosion of a furnace lining, and the weight calculation formula is as follows:
1) slag mass calculation
SiO in the slag by using the principle of mass balance2The weight of (A) is mainly derived from the oxidation of Si element and SiO in slag-forming material2：
Weight of Si element oxidation product:
W(SiO2)＝2.14×[Wt(Si1-Si3)+Wfg(Si2-Si3)]
total SiO in slag2Quality:
the weight of the slag may be expressed as:
Wz＝WzSiO2/ωzSiO2
2) slag Density calculation
1/ρ＝0.416％SiO2+0.303％CaO+0.212％FeO+0.350％Fe2O3 +0.238％MnO+0.372％MgO+0.324％P2O5+0.328Al2O3
The above formula is a semi-empirical formula for calculating T1400 ℃, and for other temperatures, an average coefficient of temperature expansion may be used
Performing conversion calculation, wherein
In the formula, ρPractice ofRepresenting the actual density, T, of the slag1Representing the actual temperature of the slag.
3) Slag volume calculation
when the converter tilts, the slag liquid level is elliptic, the diameter of the slag elliptic interface is reduced along with the reduction of the smelting height, the real-time monitoring of the diameter of the slag liquid level ellipse can be realized through the furnace top sensor 1, so that the real-time calculation of the slag liquid level diameter is realized, and the calculation formula is as follows:
S＝π·A·B
in the formula, A represents the long axis of the slag elliptical interface, B represents the short axis of the slag elliptical interface, and the slag liquid level area can be calculated.
4) Thickness of slag
The change of the slag smelting A is monitored in real time through a furnace mouth sensor, and the thickness of a slag layer can be calculated in real time.
5) Calculation of molten steel level height calibration
Microwave sensors, shown in FIG. 3 and respectively designated as microwave sensor 1 and microwave sensor 2, are installed above the taphole and at the tap hole, and before tapping begins, the microwave sensor 1 detects the vertical height of the slag to the liquid level, designated as H2The vertical distance from the microwave sensor 1 to the microwave sensor 2 is detected and recorded as H3Then, the height H from the molten steel level to the tapping hole can be calculated according to the following formula:
H＝H3-H2-H1
the height from the liquid level of the molten steel to the steel tapping hole can be calibrated and calculated according to the formula, and important reference is provided for realizing slag-free steel tapping.
(3) Dynamic tapping based on temperature control
Eccentric stove bottom tapping mode sets up the tap-hole in stove bottom eccentric district, consequently if adopt traditional tap-hole, after opening the tap-hole, the molten steel sprays under the effect of hydrostatic pressure and goes out, and its tap-hole speed can't be controlled by operating personnel, has designed the valve formula tap-hole that can dynamically adjust the tap-hole size based on this paper, and its concrete structure is as shown in figure 4, and its major structure includes: movable baffle, hydraulic transmission pole, baffle movable slot.
The control principle of the valve opening size is carried out based on the molten steel temperature, and the collected TSO temperature is recorded as T1And the target tapping temperature is recorded as T2The temperature drop rate of the molten steel is delta T, and the ideal tapping time can be calculated
Based on the quality of the molten steel and the ideal tapping time, the weight flow W (kg/h) of the molten steel can be calculated
Wherein M represents the quality of molten steel in the converter. And if the density of the molten steel is rho steel, the average flow velocity v of the molten steel. The calculation formula of the open drift diameter of the steel tapping hole is as follows:
in the formula: d-the drift diameter of the steel tapping hole is mm; w represents the mass flow of molten steel, kg/h; rho-molten steel density, kg/m 3; v-average flow velocity of molten steel, m/s.
(4) Protective sleeve
In the tapping process, in order to protect the molten steel and reduce the suction amount of the molten steel and the heat loss in the process, the invention provides that a magnesium protective sleeve is additionally arranged at a tapping hole.
The inner diameter of the protective sleeve is larger than the diameter of the steel tapping hole and is 1.5 times of the diameter of the steel tapping hole, firstly, the protective sleeve is convenient to be installed in a butt joint mode with the steel tapping hole, and secondly, a gas gap is formed between molten steel flow and the inner wall of the protective sleeve, and a certain heat insulation effect is achieved.
The protective sleeve is divided into three layers, as shown in figure 5, a working layer is built by refractory bricks, the refractory bricks are magnesia carbon bricks, and the thickness of the refractory bricks is about 6 cm; the middle layer is a heat insulation layer, the heat insulation material is an asbestos plate, the thickness of the heat insulation material is 3cm, the outer layer is an iron shell, the thickness of the outer layer is 1cm, and the total thickness of the wall of the protective sleeve is 10 cm. The length is 1.5 m.
In the process of tapping at the eccentric bottom of the converter, the molten steel flow velocity is large under the action of hydrostatic pressure, the function of stable flow can be realized by adopting the protective sleeve, the molten steel and external air can be isolated, the suction of the molten steel is reduced, and in addition, because the protective sleeve is provided with a heat insulation layer, the heat loss of the molten steel in the tapping process can be reduced to a great extent, and the protective sleeve has great significance for reducing the tapping temperature and realizing cost reduction and efficiency improvement.
(5) Lifting buggy ladle
In order to realize the protection to the tapping process, after the protective sleeve is installed, the protective sleeve is guaranteed to have a certain immersion depth in the steel ladle, the protective sleeve is fixed in length and cannot be directly introduced into the steel ladle, the height of the steel ladle is required to be lifted by the aid of a steel ladle lifter at the moment, and the immersion of the protective sleeve is realized. The lifting buggy ladle structure is shown in fig. 6 and mainly comprises three parts: ladle automobile body, fluid pressure type support frame, ladle platform. The ladle is arranged on the ladle platform, and after smelting, the buggy ladle that carries the ladle is driven to under the tapping hole, and operating personnel control hydraulic support frame promotes the ladle height, stops when dipping into the inside 0.5m of ladle until protective case, opens the argon bottom blowing valve this moment, gets rid of the air of detaining in the ladle inside after, opens the tapping hole, realizes the protection tapping. Along with the tapping process, the liquid level of the molten steel in the steel ladle gradually rises, and along with the rise of the liquid level, the lifting height of the steel ladle is gradually reduced, so that the protective sleeve is prevented from contacting with the liquid level of the molten steel.
Example 1:
in the specific embodiment of the invention, as shown in fig. 7, the dynamic tapping method at the eccentric bottom of the converter is characterized in that for a 120t cylindrical-spherical converter, when tapping is prepared after smelting, the following steps are adopted:
(1) the converter was turned to 30 °, and the tap hole was turned to the lowest point, in a vertical state, and perpendicular to the horizontal plane, as shown in fig. 6.
(2) Calculating the thickness of the slag and calibrating the height of a molten steel pool:
firstly, collecting material information of a current heat, wherein the specific information is as follows:
TABLE 1 addition of raw and auxiliary materials
TABLE 2 composition parameters of the metal charge
| Species of | C | Si | Mn | P | S | T |
| Molten iron | 4.5 | 0.3425 | 0.163 | 0.1196 | 0.0254 | 1386 |
| Scrap steel | 0.18 | 0.2 | 0.92 | 0.023 | 0.025 | 25 |
| TSO test | 0.111 | 0.001 | 0.077 | 0.014 | 0.026 | 1640 |
| Target temperature | 0.12 | / | / | ＜0.025 | ＜0.025 | 1630 |
TABLE 3 slag-forming material composition parameters
| Species of | CaO | SiO2 | MgO | Al2O3 | S | P | Fe2O3 |
| Lime | 0.902 | 0.015 | 0.035 | 0.005 | 0.00225 | 0.0001 | 0 |
| Light burning | 0.4605 | 0.0208 | 0.398 | 0 | 0.001125 | 0 | 0 |
| Raw white | 0.5 | 0.00377 | 0.36 | 0 | 0 | 0 | 0 |
| Ore ore | 0.099 | 0.047 | 0 | 0 | 0.00135 | 0.001 | 73.2 |
TABLE 4 slag composition test
| Composition (I) | CaO/wt％ | SiO2/wt％ | MgO/wt％ | MnO/wt％ |
| Ratio of occupation of | 47.34 | 17.69 | 8.93 | 2.45 |
| Composition (I) | P2O5/wt％ | Al2O3/wt％ | FeO/wt％ | Fe2O3/wt％ |
| Ratio of occupation of | 4.94 | 1.93 | 8.01 | 6.47 |
The calculation result of the slag thickness after the implementation of the present example is:
1) slag mass calculation
Weight of Si element oxidation product:
W(SiO2)＝2.14×[118000×0.01×(0.3425-0.001)+30000×0.01×(0.2-0.001)]＝900.1138
material carried into SiO2Weight (D)
WSiO2＝4503×0.015+1587×0.0208+1437×0.047＝168.0936
Total mass of slag
(Note: other elements can also be used to balance the calculated slag mass)
2) Slag Density calculation
Slag density at 1640 DEG C
ρ＝3.14-2.4×0.04＝3.044g/cm3
3) Slag volume calculation
4) Slag thickness calculation
The microwave sensor 1 measures the minor axis length of 3m, the major axis length of 3.46m and the interface area of the slag ellipse surface
S＝π×3×3.46＝32.59
5) Liquid level height calculation
The microwave sensor 1 measures the height H from the microwave sensor to the molten slag liquid level27.037m, the microwave sensor 2 detects the tap hole to sensorThe vertical distance H3 between the devices 1 is 7.97m, and the height of the molten steel level can be calculated according to the calibration
H＝H3-H2-H1＝7.97-7.037-0.0680＝0.8722m。
(3) And (4) calculating the size of the open drift diameter of the steel tapping hole.
The average temperature drop speed of the converter is 15 ℃/min, the temperature of the molten steel measured based on TSO is 1660 ℃, the target tapping temperature of the ladle is 1630 ℃, the mass of the molten steel is 135t, and the density of the molten steel is 7000kg/m3The average flow velocity was 5m/s, and it was found that:
and calculating the open drift diameter of the steel tapping hole according to the formula to be 20.23 cm.
(4) Aiming at a 120t converter, the diameter of a steel tapping hole is 16.52cm, so that a protective sleeve with the inner diameter of 24.8cm, the wall thickness of 10cm and the length of 1.5m is selected, the protective sleeve is butted with the steel tapping hole, a buggy ladle is moved to the position right below the steel tapping hole, the height of the ladle is lifted by using a buggy ladle lifter, the protective sleeve is immersed into the position of 0.5m in the ladle, and argon bottom blowing of the ladle is started.
(5) Because the calculated d is 20.23cm and is larger than the diameter of the steel tapping hole, according to the calculation result, an operator sends an instruction to the control box through the central control computer to control the hydraulic rod to open the steel tapping hole to the maximum caliber of 16.52 cm.
(6) Along with the proceeding of tapping, the liquid level of molten steel and slag in the converter descends, the liquid level height is monitored by a furnace mouth and a tapping hole sensor in real time, when the liquid level height descends to 95% (H is 0.04m) of the liquid level height of the molten steel obtained by calibration calculation, the drift diameter of the tapping hole is controlled to be reduced, and when the liquid level height reaches 98-99% (H is 0.008-0.017 m), the tapping hole is controlled to be completely closed, so that slag rolling is avoided, and slag-free tapping is realized.
(7) And (4) dropping the ladle lifter, driving the ladle car out of the steel tapping position, removing the protective sleeve, shaking the ladle body to perform slag splashing furnace protection operation, and directly or after slag dumping, performing furnace discharging smelting after slag splashing furnace protection is finished. And finishing the tapping process.
Example 2:
this example is similar to example 1, except that for a 200t converter, the dynamic tapping operation can be described simply as:
(1) the converter is turned to 32 degrees, so that the tapping hole is at the lowest point and is vertical to the horizontal plane.
(2) And extracting the charging information and the end point information of the current heat, calculating to obtain the initial slag thickness of 0.092m, and calibrating to obtain the initial liquid level height of the molten steel of 1.25 m.
(3) The diameter of the steel tapping hole is 20.35 cm. Selecting a protective sleeve with the diameter of 30.5cm, sleeving the protective sleeve on the steel tapping hole, moving the buggy ladle to the position right below the steel tapping hole, lifting the height of the ladle by using a buggy ladle lifter, immersing the protective sleeve into the position of 0.5m in the ladle, and starting argon bottom blowing of the ladle.
(4) When the smelting of the converter is finished, the temperature drop speed is 10 ℃/min, the temperature of the molten steel measured based on the TSO is 1710, and the target tapping temperature is 1660. The molten steel mass is 215t, and the opening drift diameter of the steel outlet is calculated to be 14.4 cm.
(5) According to the calculation result, an operator sends an instruction to the control box through the central control computer to control the hydraulic rod to open the steel tapping hole, and the open drift diameter of the steel tapping hole is 14.4 cm.
(6) Along with the proceeding of tapping, the liquid level of molten steel and slag in the converter descends, the ferrostatic pressure at the tapping hole can be reduced, the molten steel outflow speed can be slowed down, and at the moment, the tapping speed can be dynamically adjusted by increasing the diameter of the tapping hole by an operator, so that the rapid ladle protection tapping is ensured.
(7) The liquid level height is monitored by the furnace mouth and the steel tapping hole sensor in real time, when the liquid level height is reduced to 95% of the liquid level height of molten steel obtained through calibration calculation (H is 0.0625m), the drift diameter of the steel tapping hole is controlled to be reduced, and when the liquid level height reaches 98-99% (H is 0.012-0.025 m), the steel tapping hole is controlled to be completely closed, so that slag rolling is avoided, and slag-free steel tapping is realized.
(8) And (4) dropping the ladle lifter, driving the ladle car out of the steel tapping position, removing the protective sleeve, shaking the ladle body to perform slag splashing furnace protection operation, and directly or after slag dumping, performing furnace discharging smelting after slag splashing furnace protection is finished. And finishing the tapping process.
Example 3:
this example is similar to example 1, except that for a 300t converter, the dynamic tapping operation can be described simply as:
(1) the converter is turned to 35 degrees, so that the tapping hole is at the lowest point and is vertical to the horizontal plane.
(2) And extracting the charging information and the end point information of the current heat, calculating to obtain the initial slag thickness of 0.112m, and calibrating to obtain the initial liquid level height of the molten steel of 1.65 m.
(3) The diameter of the steel tapping hole is 24.25cm, a protective sleeve with the diameter of 36.5cm is selected and sleeved on the steel tapping hole, the buggy ladle is moved to the position right below the steel tapping hole, the height of the ladle is lifted by using a buggy ladle lifter, the protective sleeve is immersed into the position of 0.5m in the ladle, and argon bottom blowing of the ladle is started.
(4) When the smelting of the converter is finished, the temperature drop speed is 10 ℃/min, the temperature of the molten steel measured based on TSO is 1680 ℃, the target tapping temperature is 1650 ℃, the quality of the molten steel is 313t, and the size of the open drift diameter of the tapping hole is calculated to be 22.15cm
(5) According to the calculation result, an operator sends an instruction to the control box through the central control computer to control the hydraulic rod to open the steel tapping hole, and the open drift diameter of the steel tapping hole is 22.15 cm.
(6) Along with the proceeding of tapping, the liquid level of molten steel and slag in the converter descends, the liquid level height is monitored by a furnace mouth and a tapping hole sensor in real time, when the liquid level height descends to 95% (H is 0.0825) of the liquid level height of the molten steel obtained by calibration calculation, the drift diameter of the tapping hole is controlled to be reduced, and when the liquid level height reaches 98-99% (H is 0.016-0.033 m), the tapping hole is controlled to be completely closed, so that slag rolling is avoided, and slag-free tapping is realized.
(7) And (4) dropping the ladle lifter, driving the ladle car out of the steel tapping position, removing the protective sleeve, shaking the ladle body to perform slag splashing furnace protection operation, and directly or after slag dumping, performing furnace discharging smelting after slag splashing furnace protection is finished. And finishing the tapping process.
The method and the device for controlling dynamic tapping at the eccentric bottom of the converter provided by the embodiment of the application are described in detail above. The above description of the embodiments is only for the purpose of helping to understand the method of the present application and its core ideas; meanwhile, for a person skilled in the art, according to the idea of the present application, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present application.
As used in the specification and claims, certain terms are used to refer to particular components. As one skilled in the art will appreciate, manufacturers may refer to a component by different names. This specification and claims do not intend to distinguish between components that differ in name but not function. In the following description and in the claims, the terms "include" and "comprise" are used in an open-ended fashion, and thus should be interpreted to mean "include, but not limited to. "substantially" means within an acceptable error range, and a person skilled in the art can solve the technical problem within a certain error range to substantially achieve the technical effect. The description which follows is a preferred embodiment of the present application, but is made for the purpose of illustrating the general principles of the application and not for the purpose of limiting the scope of the application. The protection scope of the present application shall be subject to the definitions of the appended claims.
It is also noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a good or system that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such good or system. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a commodity or system that includes the element.
It should be understood that the term "and/or" as used herein is merely one type of association that describes an associated object, meaning that three relationships may exist, e.g., a and/or B may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.
The foregoing description shows and describes several preferred embodiments of the present application, but as aforementioned, it is to be understood that the application is not limited to the forms disclosed herein, but is not to be construed as excluding other embodiments and is capable of use in various other combinations, modifications, and environments and is capable of changes within the scope of the application as described herein, commensurate with the above teachings, or the skill or knowledge of the relevant art. And that modifications and variations may be effected by those skilled in the art without departing from the spirit and scope of the application, which is to be protected by the claims appended hereto.
Claims (8)
1. A dynamic tapping control method for an eccentric furnace bottom of a converter is characterized by comprising the following steps:
s1, after the converter finishes converting, rotating the furnace body to rotate the steel tapping hole to the lowest position; the tapping hole is arranged in the eccentric area of the furnace and avoids the bottom blowing area;
s2, determining the opening size of the drift diameter of the steel tapping hole based on temperature control; the control principle is as follows: calculating ideal tapping time according to the TSO temperature, the target tapping temperature and the temperature drop rate of the molten steel; calculating to obtain the weight flow of the molten steel based on the quality of the molten steel and the ideal tapping time; calculating the opening size of the drift diameter of the steel tapping hole based on the molten steel weight flow meter;
s3, mounting a protective sleeve at the steel tapping hole and positioning a steel ladle;
s4, opening the steel tapping hole according to the result of S2, and tapping in a protective atmosphere;
s5, closing the steel tapping hole when the liquid level of molten steel in the converter is reduced to a preset height, and straightening the converter body;
s6, slag splashing and furnace protection, and tapping is finished;
the specific content of step S5 includes: when the liquid level height of the molten steel is reduced to 5% of the original height, the drift diameter of the steel-tapping hole is gradually reduced, and when the liquid level height of the molten steel is reduced to 1% -2% of the original height, the steel-tapping hole is completely closed;
the calculation mode of the liquid level height of the molten steel is as follows: a first microwave sensor is arranged above the furnace mouth for measuring the vertical distance H between the first microwave sensor and the liquid level of the slag2Meanwhile, a second microwave sensor is arranged at the steel tapping hole for measuring the vertical distance H between the two microwave sensors3Calculating the slag thickness H according to the read smelting data1When the height H of molten steel surface is equal to H3-H2-H1。
2. The dynamic tapping control method for the eccentric furnace bottom of the converter according to claim 1, characterized in that the ladle adopts a lifting ladle car, the height of the ladle is dynamically adjusted according to actual conditions during the tapping process, and a protective sleeve is prevented from contacting molten steel in the ladle.
3. The dynamic tapping control method for the eccentric furnace bottom of the converter according to claim 2, characterized in that an argon bottom-blowing valve is arranged in the steel ladle, and the argon bottom-blowing valve is opened to discharge air in the steel ladle before tapping, so as to realize atmosphere protection tapping.
4. The dynamic tapping control method for the eccentric hearth of the converter according to claim 1, wherein the tapping hole is provided at 3/4 of the radius of the cross section of the segment of the button; the included angle between the steel tapping hole and the vertical direction ranges from 30 degrees to 40 degrees, and the distance between the steel tapping hole and the edge of the furnace bottom ranges from 0.375m to 0.75 m.
5. A control device for dynamic tapping at the eccentric bottom of a converter, which comprises the eccentric furnace of the converter and a ladle, and is characterized in that the control device is used for realizing the control method of any one of claims 1 to 4;
the steel tapping hole of the converter eccentric furnace is arranged in the eccentric area and avoids the bottom blowing area; the opening size of the drift diameter of the steel tapping hole is adjustable based on temperature control; a protective sleeve is arranged at the steel tapping hole; the steel ladle is a lifting type steel ladle, and the height of the steel ladle can be adjusted in the tapping process; and a protective atmosphere bottom blowing structure is arranged in the steel ladle and used for realizing protective tapping.
6. The dynamic tapping control device at the eccentric bottom of the converter according to claim 5, wherein the wall of the protective sleeve has a three-layer layered structure; a working layer built by refractory bricks, a heat insulation layer and an iron outer shell layer from inside to outside.
7. The dynamic tapping control device at the eccentric hearth of the converter according to claim 5, wherein the tapping hole is provided at 3/4 of the radius of the cross section of the segment of the converter; the included angle between the steel tapping hole and the vertical direction ranges from 30 degrees to 40 degrees, and the distance between the steel tapping hole and the edge of the furnace bottom ranges from 0.375m to 0.75 m.
8. The dynamic steel tapping control device at the eccentric bottom of the converter according to claim 5, wherein a first microwave sensor is arranged above the fire hole of the eccentric furnace of the converter and is used for measuring the vertical height of the slag liquid level and the diameter of the slag liquid level in real time; and a second microwave sensor is arranged at the steel tapping hole and used for measuring the vertical distance between the two microwave sensors in real time.
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| CN114581859B (en) * | 2022-05-07 | 2022-09-13 | 北京科技大学 | Converter slag discharging monitoring method and system |
| CN117165733A (en) * | 2022-05-27 | 2023-12-05 | 宝山钢铁股份有限公司 | Method and system for identifying slag quantity of automatic slag pouring of converter in real time |
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| DE19826085C2 (en) * | 1998-06-12 | 2000-08-03 | Sms Demag Ag | Method and device for sealing a tap opening in metallurgical vessels |
| CN1333380A (en) * | 2000-11-23 | 2002-01-30 | 莱芜钢铁股份有限公司炼钢厂 | Tapping outlet for converter |
| CN101368223A (en) * | 2008-10-07 | 2009-02-18 | 北京科技大学 | Method for deflection bottom tapping of revolving furnace |
| KR101502424B1 (en) * | 2013-08-30 | 2015-03-13 | 주식회사 포스코 | Apparatus for transferring molten steel in converter |
| CN103834762A (en) * | 2014-03-06 | 2014-06-04 | 北京科技大学 | Converter eccentric bottom tapping device and application method thereof |
| CN105274275A (en) * | 2015-11-06 | 2016-01-27 | 攀钢集团攀枝花钢铁研究院有限公司 | Method for reducing rephosphorization during semi-steel steelmaking |
| CN108115120B (en) * | 2017-02-28 | 2024-01-30 | 安徽工业大学 | Protective tube for molten steel tapping process |
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