Steel ladle baking system with dynamic flame blowing and baking function and baking method

Abstract

The invention discloses a dynamic flame blowing and baking steel ladle baking system and method. The system comprises a steel ladle, a movable burner device and a gas blowing device. The movable burner device is arranged at the top of the steel ladle and comprises a bearing plate, a moving trolley, a moving motor and a burner. The gas blowing device is arranged at the bottom of the steel ladle, and an exhaust port of the gas blowing device is communicated with the bottom of an inner cavity of the steel ladle. Dynamic flames are provided through the movable burner device at the top of the steel ladle, the penetrating effect of the flames is improved, effective impact on waste steel in all areas and all depths in the steel ladle is achieved, and uniform preheating is achieved; and hot flue gas or fuel gas is sprayed from the bottom of the steel ladle, so that the heating strength of the steel scrap at the bottommost layer is enhanced, the occurrence of a local cold region caused by too low temperature of the steel scrap is avoided, finally, uniform heating and preheating of the steel scrap are realized, and the system investment and the operation cost are greatly reduced.

Description

Technical Field

[0001] The invention relates to ladle preheating equipment and preheating technology, in particular to a dynamic flame blowing ladle baking system and baking method, belonging to the technical field of steel production. Background Art

[0002] In the steelmaking process, the ladle is an important device used to receive high-temperature molten steel at the lower part of the discharge port of steelmaking equipment such as converters or electric furnaces, and transport the molten steel to the back-end refining process. A cold ladle at room temperature cannot directly receive molten steel at up to 2000 degrees Celsius, which will cause the refractory of the ladle to crack and break instantly. Therefore, before receiving molten steel, it is usually necessary to bake the ladle as a whole to above 1150 degrees Celsius with an external burner heat source, and then use a hot ladle to receive the molten steel. In the current market, some repurchased scrap steel has good quality and purity, and does not need to be smelted in a converter or electric furnace. It can generally be directly added to the back-end refining process. However, adding cold scrap steel directly to the refining will cause local cold zones in the furnace. Therefore, before the ladle is baked, adding an appropriate amount of scrap steel so that the ladle can be baked and preheated with the scrap steel, and then receive molten steel and go to the refining process together has become a common method to reduce costs and increase efficiency in the current industry market. However, at present, the ladle baking device that uses a large proportion of scrap steel has the following three major defects in the production process.

[0003] (1) Poor preheating and equalization of scrap steel: After a large proportion of scrap steel is added, it will accumulate into a thick column in the ladle, which will affect or even hinder the flame of the top burner from transferring heat downward. This will cause the scrap steel on the top to be baked to a molten state by the high-temperature flame, while the scrap steel at the bottom has not yet heated up in time. After the ladle receives the molten steel, a local cold zone will form at the bottom, causing the molten steel to condense. This will not only hinder the implementation of the argon bottom blowing process at the bottom of the ladle in the back-end refining process, but the condensed molten steel will also continue to adhere to the bottom of the ladle, resulting in a significant reduction in the number of times the ladle can be used.

[0004] (2) Poor ladle baking quality: As mentioned above, since the heat from the burner flame cannot be transmitted to the bottom of the ladle, the temperature at the bottom of the ladle cannot be effectively increased synchronously, which loses the original purpose of baking the ladle. When it suddenly comes into contact with ultra-high temperature molten steel, it is easy to cause cracking, breakage and other accidents.

[0005] (3) Short life of ladle lining: On the one hand, the quality of ladle baking deteriorates, and on the other hand, the molten steel will continue to stick to the bottom of the ladle, resulting in a significant shortening of the life cycle of the ladle lining, which greatly increases the production cost. Summary of the invention

[0006] In view of the problems in the prior art of adding scrap steel into the ladle for coordinated baking of the ladle, such as poor preheating and uniform heating effect of the scrap steel, poor ladle baking quality, short life of the ladle lining, the present invention provides a ladle baking system with dynamic flame blowing and baking and a method for baking a ladle using the system. A dynamic flame is provided by a mobile burner device arranged on the top of the ladle, which improves the penetration effect of the flame and achieves effective impact on the scrap steel in various areas and at various depths in the ladle. Furthermore, hot flue gas or fuel gas is sprayed from the bottom of the ladle to enhance the heating intensity of the scrap steel in the bottom layer, thereby preventing the occurrence of local cold zones caused by too low scrap steel temperature, and ultimately achieving uniform preheating of the scrap steel, thereby reducing system investment and operating costs.

[0007] In order to achieve the above technical objectives, the technical solutions adopted by the present invention are as follows:

[0008] According to a first embodiment of the present invention, a dynamic flame blowing ladle baking system is provided:

[0009] A dynamic flame blowing ladle baking system, the system comprises a ladle, a movable burner device and a gas blowing device. The movable burner device comprises a bearing plate, a moving vehicle, a moving motor and a burner. The bearing plate is arranged on the top of the ladle. The moving vehicle is arranged on the upper surface of the bearing plate. The moving motor is arranged on the moving vehicle. A through moving slit is provided on the bearing plate, the upper end of the burner passes through the moving slit and is connected to the moving vehicle, and the other end of the burner extends downward to the interior of the ladle. The moving vehicle drives the burner to move horizontally along the moving slit under the drive of the moving motor. The gas blowing device is arranged at the bottom of the ladle, and the exhaust port of the gas blowing device is connected to the bottom of the inner cavity of the ladle.

[0010] Preferably, the overall shape of the movable seam in the horizontal plane is one of a straight line, a cross, a circle (circular ring), an ellipse (elliptical ring), a triangle, a rectangle, a regular polygon or an irregular polygon, preferably a cross or a circle.

[0011] Preferably, the gas blowing device includes a bottom blowing ring pipe, a bottom blowing branch pipe, a bottom air chamber, a porous brick and a bottom blowing hole. The porous brick is arranged at the bottom of the ladle, the bottom blowing air chamber is arranged below the porous brick, the bottom blowing hole is opened on the porous brick, and the bottom blowing air chamber is connected to the bottom of the inner cavity of the ladle through the bottom blowing hole. The bottom blowing ring pipe is arranged around the outer side of the bottom air chamber and is connected to the bottom air chamber through the bottom blowing branch pipe. The air inlet of the bottom blowing ring pipe is connected to a flue gas conveying pipe and a fuel gas conveying pipe, and gas valves are independently arranged on the flue gas conveying pipe and the fuel gas conveying pipe. Preferably, in the circumferential direction of the bottom blowing ring pipe, the bottom blowing ring pipe is connected to the bottom air chamber through multiple bottom blowing branches.

[0012] Preferably, the bottom blowing hole is one or more of a circular hole, a long strip hole or a square hole. The diameter of the upper outlet of the bottom blowing hole is smaller than the diameter of the lower inlet.

[0013] Preferably, a plurality of the bottom blowing holes are provided on the porous brick, and the plurality of the bottom blowing holes are distributed on the porous brick in any arrangement.

[0014] Preferably, the system further comprises a spring weighing device, wherein the spring weighing device is arranged between the gas blowing device and the ground.

[0015] Preferably, the system further comprises a control device, which is electrically connected to the mobile burner device and the gas blowing device, and the working state of the mobile burner device and the gas blowing device is regulated by the control device. At the same time, the control device is also electrically connected to the spring weighing device, so as to receive the scrap steel weight data fed back by the spring weighing device.

[0016] According to a second embodiment of the present invention, a ladle baking method is provided:

[0017] A ladle baking method or a ladle baking method using the dynamic flame blowing ladle baking system of the first embodiment, the method comprising the following steps:

[0018] 1) Add scrap steel into a ladle, and calculate the preheating coefficient for baking the ladle based on the mass of the added scrap steel.

[0019] 2) The moving speed of the burner, the gas flow rate supplied to the burner, and the gas flow rate and / or flue gas flow rate injected by the gas injection device into the bottom of the inner cavity of the ladle when baking the ladle are calculated based on the calculated preheating coefficient.

[0020] 3) Parameters are set according to the calculated burner movement speed, gas flow supplied to the burner, and gas flow and / or flue gas flow injected into the bottom of the inner cavity of the ladle by the gas injection device, and the ladle is baked according to the set parameters until the ladle meets the requirements for holding molten steel.

[0021] Preferably, step 1) is specifically as follows: the total mass of scrap steel in the ladle is measured by a spring weighing device and recorded as W, kg. Then the preheating coefficient β, kJ / mm, when the ladle is baked is:

[0022] β=(W*Cp*Tp) / D(I).

[0023] In formula (I): Cp is the average specific heat capacity of the scrap steel, kJ / (kg·°C). Tp is the average target temperature at which the scrap steel is preheated, °C. D is the average particle size of the scrap steel, mm.

[0024] As a preferred embodiment, step 2) is specifically as follows: when the ladle is baked, the moving speed of the burner is recorded as V, r / min. The gas flow rate supplied to the burner is recorded as Q1, m 3 / min. The gas flow rate injected by the gas injection device into the bottom of the inner cavity of the ladle is recorded as Q2, m 3 / min. The flue gas flow rate injected by the gas injection device into the bottom of the inner cavity of the ladle is recorded as Q3, m 3 / min. Then:

[0025] V=a*β+b (II).

[0026] Q1=(c*β+Cp*β) / u (III).

[0027] Q2=Q 1* Z (IV).

[0028] Q3 = (Cr / Cy)*Q2 (V).

[0029] In formulas (II)-(V): a is the movement correction coefficient, (r·mm) / (kJ·min), with a value of 0.001-1. b is the movement correction constant, with a value of 1-50. c is the gas flow correction coefficient, kJ / (kg·℃), with a value of 0.001-1. u is the gas flow correction constant, (kJ 2 ·min) / (kg·℃·mm·m 3 ), with a value of 1000-5000. Z is the porosity of the scrap steel layer, with a value of 0.05-0.5. Cy is the calorific value of flue gas, kJ / kg; Cr is the calorific value of fuel gas, kJ / kg.

[0030] It should be noted that all formulas in the present invention are obtained by fitting by the inventor based on experiments and engineering applications, and all calculations are numerical values ​​converted according to prescribed units, and are obtained by substituting the numerical values ​​after conversion into the formulas (after conversion of the units, only the numerical values ​​are substituted into the formulas for calculation, without substituting the units, and the units are only used to adjust the size of the numerical values).

[0031] Preferably, the flue gas injected by the gas injection device into the bottom of the inner cavity of the ladle is hot flue gas generated by the system or hot flue gas generated by other processes in the steel plant, and the temperature range of the hot flue gas is 700°C-1200°C, and the oxygen content is 5%-16%.

[0032] In the present invention, a movable burner device is provided on the top of the ladle, so that the flame ejected downward by the burner is a dynamic flame that moves periodically inside the ladle. During the movement, the flame will not remain in a certain position, so that the scrap steel in different areas (different areas of the horizontal plane) can be preheated to achieve uniform preheating. At the same time, it can also effectively enhance the radiation impact on the inner layer of scrap steel below and even the bottom layer of scrap steel, improve the preheating effect of the scrap steel in the vertical interval, and is conducive to achieving the purpose of overall uniform preheating of all scrap steel in the ladle.

[0033] Furthermore, in the present invention, the mobile burner device may be provided with multiple burners, and the multiple burners are evenly and distributedly arranged along the moving seam, and the multiple burners move synchronously, which can provide multiple regularly moving dynamic flames in the ladle, further enhancing the overall uniform preheating effect of the scrap steel inside the ladle. Furthermore, the depth of each burner extending into the ladle can be adjusted, so that the depth of each burner is the same or different, and the gas supply of each burner can also change regularly with the depth of its penetration into the ladle (for example, as the depth of penetration into the ladle increases, the real-time supply of gas gradually increases or decreases or remains unchanged), thereby effectively improving the preheating effect of the inner scrap steel, especially the bottom scrap steel.

[0034] In the present invention, a gas blowing device is also added at the bottom of the ladle, which mainly includes a bottom blowing ring pipe, a bottom blowing branch pipe, a bottom air chamber, a porous brick and a bottom blowing hole. Hot flue gas and / or fuel gas (coal gas) are sprayed into the bottom of the inner cavity of the ladle through the gas blowing device. The injected hot flue gas itself can exchange heat with the cold scrap steel and drive the flow of the air flow in the ladle, thereby strengthening the preheating effect of the bottom scrap steel. At the same time, the injected coal gas is also ignited, releasing new heat to further strengthen the preheating of the bottom scrap steel. By adding a gas blowing device to the bottom of the ladle, uniform preheating of the scrap steel at the bottom of the ladle is achieved, and the occurrence of local cold zones caused by too low scrap steel temperature in the prior art is eliminated.

[0035] In the present invention, a spring weighing device is also provided at the bottom of the gas blowing device, the purpose of which is to accurately obtain the weight of scrap steel added into the ladle before each ladle baking operation, thereby facilitating the control device to accurately adjust the parameters of each operation to ensure baking efficiency and safe operation of the system.

[0036] In the present invention, the control device has no fixed setting point, and can be set beside the system for control, or can be remotely controlled by a central control room, according to the actual working conditions, as long as it can meet the control function of the system. The control device of the present invention belongs to the category of mature parameter feedback adjustment control devices (existing products can be purchased directly from the market, and only the corresponding parameters need to be adjusted according to the working conditions).

[0037] In the present invention, when the system or method of the present invention is used to carry out ladle baking production, the system will first obtain the accurate weight W, kg, of the scrap steel added to the ladle through a spring weighing device. Then, combined with the scrap steel particle size D, mm detected at the raw material field, the preheating coefficient β of this ladle baking is calculated. The formula is as follows:

[0038] β=(W*Cp*Tp) / D(I).

[0039] In formula (I): Cp is the average specific heat capacity of the scrap steel, kJ / (kg·°C). Tp is the average target temperature at which the scrap steel is preheated, °C. D is the average particle size of the scrap steel, mm.

[0040] After obtaining the preheating coefficient β, the system will calculate the burner moving speed V, r / min, during the ladle baking process based on β. The gas flow rate Q1, m 3 / min, gas flow rate Q2, m 3 / min, the flue gas flow rate injected into the bottom of the inner cavity of the ladle by the gas blowing device is recorded as Q3, m 3 / min, their calculation formulas are as follows:

[0041] V=a*β+b (II).

[0042] Q1=(c*β+Cp*β) / u (III).

[0043] Q2=Q 1* Z (IV).

[0044] Q3 = (Cr / Cy)*Q2 (V).

[0045] In formulas (II)-(V): a is the movement correction coefficient, (r·mm) / (kJ·min), with a value of 0.001-1. b is the movement correction constant, with a value of 1-50. c is the gas flow correction coefficient, kJ / (kg·℃), with a value of 0.001-1. u is the gas flow correction constant, (kJ 2 ·min) / (kg·℃·mm·m 3 ), with a value of 1000-5000. Z is the porosity of the scrap steel layer, with a value of 0.05-0.5. Cy is the calorific value of flue gas, kJ / kg; Cr is the calorific value of fuel gas, kJ / kg.

[0046] After obtaining the burner moving speed V, the top burner gas flow Q1, the bottom non-blowing gas flow Q2 and the bottom blowing flue gas flow Q3, the system will use this as the target value, automatically adjust the moving motor power, the top gas valve opening and the bottom blowing gas valve opening, and the bottom blowing flue gas valve opening, until the V, Q1, Q2 and Q3 in the working condition have reached the system calculated target value. The burner moves periodically at the top of the ladle at a certain speed V to ensure that all areas in the ladle are evenly baked by the flame. At the same time, a certain amount of coal gas or flue gas is blown into the bottom to enter the scrap steel layer in the lower area of ​​the ladle and ignite it, thereby solving the problem of too low scrap steel temperature in the lower area of ​​the ladle. At this point, this operation is completed, and the system will intelligently implement the optimized large-scale scrap steel ladle baking production according to the estimated value. It should be noted that the above description is only a preferred embodiment of the present invention. In fact, the number and arrangement of the top burners can be randomly changed according to the actual situation on site. Conventional modifications and replacements made without departing from the technical concept of the present invention should be included in the scope of protection of the present invention.

[0047] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0048] 1: The present invention adds a mobile burner device on the top of the ladle, so that the burner moves periodically in the ladle. Due to the periodic movement of the flame, it can effectively impact the scrap steel in various areas and depths in the ladle. The high temperature of the flame can penetrate to the bottom layer of scrap steel more than the prior art, thereby improving the overall heat uniformity effect of the scrap steel in the ladle. At the same time, hot flue gas and / or fuel gas are blown into the bottom of the ladle through the bottom gas blowing device, which greatly improves the heating intensity of the bottom layer of scrap steel, thereby overcoming the problem of local cold zones in the prior art due to the excessively low scrap steel temperature.

[0049] 2: The high temperature of the flame of the present invention can radiate to the bottom of the lower layer of the ladle, and the combustion of the gas blown in from the bottom will also generate new heat, so that the overall baking quality of the ladle will be qualitatively improved. The problems of scrap steel condensation and uneven local baking of the ladle are greatly alleviated, and the service life of the ladle lining is also significantly extended.

[0050] 3: The present invention adopts a dynamic flame blowing ladle baking system with a movable burner device and a gas blowing device for ladle baking, which has the advantages of simple structure, easy operation, high control accuracy, excellent scrap steel equalization effect, low investment and operation costs, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 The figure is a schematic diagram of the overall structure of the system of the present invention.

[0052] Figure 2 It is a schematic structural diagram of the mobile burner device of the present invention.

[0053] Figure 3 This is a structural diagram of a bearing plate with a cross-shaped moving seam according to the present invention.

[0054] Figure 4 This is a structural diagram of a bearing plate with a circular movable gap according to the present invention.

[0055] Figure 5 It is a schematic diagram of the cross-sectional structure of the bottom blowing ring pipe, bottom blowing branch pipe and bottom air chamber combination of the present invention.

[0056] Figure 6 It is a top view structural schematic diagram of the combination of the bottom blowing ring pipe, the bottom blowing branch pipe and the bottom air chamber of the present invention.

[0057] Figure 7 It is a schematic structural diagram of the bottom blowing brick and the bottom blowing hole of the present invention.

[0058] Figure 8 The top view of the bottom blowing brick with circular bottom blowing holes of the present invention.

[0059] Fig. 9 The top view of the bottom-blown brick of the present invention has multiple rows of horizontal straight-line bottom-blown holes.

[0060] Fig.10 The top view of the bottom blowing brick of the present invention has multiple rows of vertical straight bottom blowing holes.

[0061] Fig.11 Schematic diagram of the control structure of the control device of the present invention.

[0062] Fig.12 It is a control logic diagram of the method of the present invention.

[0063] Figure numerals: 1: ladle; 2: mobile burner device; 201: carrying plate; 202: mobile vehicle; 203: mobile motor; 204: burner; 205: mobile slot; 3: gas blowing device; 301: bottom blowing ring pipe; 302: bottom blowing branch pipe; 303: bottom air chamber; 304: porous brick; 305: bottom blowing hole; 306: flue gas conveying pipe; 307: fuel gas conveying pipe; 308: gas valve; 4: spring weighing device; 5: control device. DETAILED DESCRIPTION

[0064] The technical solution of the present invention is illustrated below by way of example, and the scope of protection requested by the present invention includes but is not limited to the following embodiments.

[0065] A dynamic flame blowing ladle baking system, the system comprises a ladle 1, a mobile burner device 2 and a gas blowing device 3. The mobile burner device 2 comprises a bearing plate 201, a mobile vehicle 202, a mobile motor 203 and a burner 204. The bearing plate 201 is arranged on the top of the ladle 1. The mobile vehicle 202 is arranged on the upper surface of the bearing plate 201. The mobile motor 203 is arranged on the mobile vehicle 202. A through moving slit 205 is opened on the bearing plate 201, and the upper end of the burner 204 passes through the moving slit 205 and is connected to the mobile vehicle 202, and the other end of the burner 204 extends downward to the inside of the ladle 1. The mobile vehicle 203 drives the burner 204 to move horizontally along the moving slit 205 under the drive of the mobile motor 203. The gas blowing device 3 is arranged at the bottom of the ladle 1, and the exhaust port of the gas blowing device 3 is connected to the bottom of the inner cavity of the ladle 1.

[0066] Preferably, the overall shape of the movable slot 205 in the horizontal plane is one of a straight line, a cross, a circle, an ellipse, a triangle, a rectangle, a regular polygon or an irregular polygon, preferably a cross or a circle.

[0067] Preferably, the gas blowing device 3 comprises a bottom blowing ring pipe 301, a bottom blowing branch pipe 302, a bottom air chamber 303, a porous brick 304 and a bottom blowing hole 305. The porous brick 304 is arranged at the bottom of the ladle 1, the bottom blowing air chamber 303 is arranged below the porous brick 304, the bottom blowing hole 305 is opened on the porous brick 304, and the bottom blowing air chamber 303 is connected to the bottom of the inner cavity of the ladle 1 through the bottom blowing hole 305. The bottom blowing ring pipe 301 is arranged around the outer side of the bottom air chamber 303 and is connected to the bottom air chamber 303 through the bottom blowing branch pipe 302. The air inlet of the bottom blowing ring pipe 301 is connected to a smoke delivery pipe 306 and a gas delivery pipe 307, and gas valves 308 are independently arranged on the smoke delivery pipe 306 and the gas delivery pipe 307. Preferably, in the circumferential direction of the bottom blowing ring pipe 301 , the bottom blowing ring pipe 301 is connected to the bottom air chamber 303 through a plurality of bottom blowing branch pipes 302 .

[0068] Preferably, the bottom blowing hole 305 is one or more of a circular hole, a long strip hole or a square hole. The aperture of the upper outlet of the bottom blowing hole 305 is smaller than the aperture of the lower inlet.

[0069] Preferably, a plurality of bottom blowing holes 305 are provided on the porous brick 304 , and the plurality of bottom blowing holes 305 are distributed on the porous brick 304 in any arrangement.

[0070] Preferably, the system further comprises a spring weighing device 4, wherein the spring weighing device 4 is arranged between the gas blowing device 3 and the ground.

[0071] Preferably, the system further comprises a control device 5, which is electrically connected to the mobile burner device 2 and the gas blowing device 3, and the control device 5 is used to regulate the working states of the mobile burner device 2 and the gas blowing device 3.

[0072] Example 1

[0073] like Figure 1-11 As shown, a ladle baking system for dynamic flame blowing and baking, the system comprises a ladle 1, a mobile burner device 2 and a gas blowing device 3. The mobile burner device 2 comprises a bearing plate 201, a mobile vehicle 202, a mobile motor 203 and a burner 204. The bearing plate 201 is arranged on the top of the ladle 1. The mobile vehicle 202 is arranged on the upper surface of the bearing plate 201. The mobile motor 203 is arranged on the mobile vehicle 202. A through moving slit 205 is provided on the bearing plate 201, and the upper end of the burner 204 is connected to the mobile vehicle 202 after passing through the moving slit 205, and the other end of the burner 204 extends downward to the inside of the ladle 1. The mobile vehicle 203 drives the burner 204 to move horizontally along the moving slit 205 under the drive of the mobile motor 203. The gas blowing device 3 is arranged at the bottom of the ladle 1, and the exhaust port of the gas blowing device 3 is connected to the bottom of the inner cavity of the ladle 1.

[0074] Example 2

[0075] Example 1 is repeated, except that the overall shape of the movable slot 205 in the horizontal plane is a cross.

[0076] Example 3

[0077] Example 1 is repeated, except that the shape of the movable slot 205 in the horizontal plane is circular as a whole.

[0078] Example 4

[0079] Example 3 is repeated, except that the gas blowing device 3 includes a bottom blowing ring pipe 301, a bottom blowing branch pipe 302, a bottom air chamber 303, a porous brick 304 and a bottom blowing hole 305. The porous brick 304 is arranged at the bottom of the ladle 1, the bottom blowing air chamber 303 is arranged below the porous brick 304, the bottom blowing hole 305 is opened on the porous brick 304, and the bottom blowing air chamber 303 is connected to the bottom of the inner cavity of the ladle 1 through the bottom blowing hole 305. The bottom blowing ring pipe 301 is arranged around the outer side of the bottom air chamber 303 and is connected to the bottom air chamber 303 through the bottom blowing branch pipe 302. The air inlet of the bottom blowing ring pipe 301 is connected to a smoke delivery pipe 306 and a fuel gas delivery pipe 307, and gas valves 308 are independently arranged on the smoke delivery pipe 306 and the fuel gas delivery pipe 307.

[0080] Example 5

[0081] Example 4 is repeated, except that in the circumferential direction of the bottom blowing ring pipe 301, the bottom blowing ring pipe 301 is connected to the bottom air chamber 303 through 9 bottom blowing branch pipes 302.

[0082] Example 6

[0083] Example 5 is repeated, except that the bottom blowing hole 305 is a circular hole. The diameter of the upper outlet of the bottom blowing hole 305 is smaller than the diameter of the lower inlet.

[0084] Example 7

[0085] The embodiment 5 is repeated, except that the bottom blowing hole 305 is a long strip hole. The aperture of the upper outlet of the bottom blowing hole 305 is smaller than the aperture of the lower inlet.

[0086] Example 8

[0087] Example 7 is repeated, except that a plurality of bottom blowing holes 305 are opened on the porous brick 304 , and the plurality of bottom blowing holes 305 are evenly distributed on the porous brick 304 .

[0088] Example 9

[0089] Example 8 is repeated, except that the system further includes a spring weighing device 4, and the spring weighing device 4 is arranged between the gas blowing device 3 and the ground.

[0090] Example 10

[0091] Example 9 is repeated, except that the system further includes a control device 5, and the control device 5 is electrically connected to the mobile burner device 2 and the gas blowing device 3, and the control device 5 is used to regulate the working states of the mobile burner device 2 and the gas blowing device 3.

[0092] Embodiment 11

[0093] A method for ladle baking using the system described in Example 10 comprises the following steps:

[0094] 1) Adding scrap steel into the ladle 1, and calculating the preheating coefficient when baking the ladle 1 according to the mass of the added scrap steel.

[0095] 2) The moving speed of the burner 204 when baking the ladle 1, the gas flow rate supplied to the burner 204, and the gas flow rate and flue gas flow rate injected into the bottom of the inner cavity of the ladle 1 by the gas injection device 3 are calculated based on the calculated preheating coefficient.

[0096] 3) Parameters are set according to the calculated moving speed of the burner 204, the gas flow supplied to the burner 204, and the gas flow and / or flue gas flow injected into the bottom of the inner cavity of the ladle 1 by the gas injection device 3, and the ladle 1 is baked according to the set parameters until the ladle 1 meets the requirements for holding molten steel.

[0097] Example 12

[0098] Example 11 is repeated, except that step 1) is specifically as follows: the total mass of scrap steel in the ladle 1 is detected by the spring weighing device 4 and recorded as W, kg. Then the preheating coefficient β, kJ / mm, when the ladle 1 is baked is:

[0099] β=(W*Cp*Tp) / D(I).

[0100] In formula (I): Cp is the average specific heat capacity of the scrap steel, kJ / (kg·°C). Tp is the average target temperature at which the scrap steel is preheated, °C. D is the average particle size of the scrap steel, mm.

[0101] Example 13

[0102] Example 12 is repeated, except that step 2) is specifically as follows: the moving speed of the burner 204 when the ladle 1 is baked is denoted as V, r / min. The gas flow rate supplied to the burner 204 is denoted as Q1, m 3 / min. The gas flow rate injected by the gas injection device 3 into the bottom of the inner cavity of the ladle 1 is recorded as Q2, m 3 / min. The flue gas flow rate injected by the gas injection device 3 into the bottom of the inner cavity of the ladle 1 is recorded as Q3, m 3 / min. Then:

[0103] V=a*β+b (II).

[0104] Q1=(c*β+Cp*β) / u (III).

[0105] Q2=Q 1* Z (IV).

[0106] Q3 = (Cr / Cy)*Q2 (V).

[0107] In formulas (II)-(V): a is the movement correction coefficient, (r·mm) / (kJ·min), with a value of 0.001. b is the movement correction constant, with a value of 5. c is the gas flow correction coefficient, kJ / (kg·℃), with a value of 0.1. u ​​is the gas flow correction constant, (kJ 2 ·min) / (kg·℃·mm·m 3), with a value of 1000. Z is the porosity of the scrap steel layer, with a value of 0.1. Cy is the calorific value of flue gas, kJ / kg; Cr is the calorific value of fuel gas, kJ / kg.

[0108] Method Example 1

[0109] The ladle is baked using the system described in Example 10 and the method described in Example 13, wherein: the mass of the empty ladle 1 is 40000 kg; the height of the ladle 1 is 4 m; the loading capacity of the scrap steel detected by the spring weighing device 4 is 8000 kg; the average particle size D of the scrap steel is 230 mm;

[0110] The average specific heat capacity of the scrap steel is obtained as Cp=0.72 kJ / (kg·℃); the target temperature of the scrap steel to be preheated is Tp=800℃; then the preheating coefficient β when the ladle 1 is baked is calculated according to formula (I):

[0111] β=(W*Cp*Tp) / D=40000×0.72×800÷230=100173.91kJ / mm.

[0112] Under this working condition, a=0.001, b=5, then according to formula (II), the moving speed V of the burner 204 when the ladle 1 is baking is calculated as:

[0113] V=a*β+b=0.001×100173.91+5=105.17mm / min

[0114] Under this working condition, c=0.1, u=1000, then the gas flow rate supplied to the burner 204 is calculated according to formula (III) and recorded as Q1:

[0115] Q1=(c*β+Cp*β) / u=(0.1×100173.91+0.72×100173.91)÷1000=82.14m 3 / min

[0116] Furthermore, the porosity Z of the scrap steel layer is 0.1, and the gas flow rate injected by the gas injection device 3 into the bottom of the inner cavity of the ladle 1 is calculated according to formula (IV) and recorded as Q2:

[0117] Q2=Q1*Z=82.14×0.1=8.214m 3 / min

[0118] Under this condition, the calorific value of flue gas is Cy=3000kJ / m 3 , the calorific value of the fuel gas Cr = 33000 kJ / m3; then according to formula (V), the flue gas flow rate injected by the gas injection device 3 into the bottom of the inner cavity of the ladle 1 is calculated as Q3: <h2 style=";text-align:left;direction:ltr">

[0119] <h2 style=";text-align:left;direction:ltr"> Q3 = (Cr / Cy) * Q2 = 33000 ÷ 3000 × 8.214 = 90.354 m<h2 style=";text-align:left;direction:ltr"> 3 <h2 style=";text-align:left;direction:ltr"> / min。

Claims

1. A dynamic flame blowing ladle baking system, characterized in that: The system comprises a ladle (1), a mobile burner device (2) and a gas blowing device (3); the mobile burner device (2) comprises a carrying plate (201), a moving vehicle (202), a moving motor (203) and a burner (204); the carrying plate (201) is arranged on the top of the ladle (1); the moving vehicle (202) is arranged on the upper surface of the carrying plate (201); the moving motor (203) is arranged on the moving vehicle (202); a through hole is provided on the carrying plate (201) The moving slot (205) passes through the moving slot (205), the upper end of the burner (204) is connected to the moving vehicle (202) after passing through the moving slot (205), and the other end of the burner (204) extends downward to the inside of the ladle (1); the moving vehicle (203) drives the burner (204) to move horizontally along the moving slot (205) under the drive of the moving motor (203); the gas blowing device (3) is arranged at the bottom of the ladle (1), and the exhaust port of the gas blowing device (3) is connected to the bottom of the inner cavity of the ladle (1).

2. The ladle baking system according to claim 1, characterized in that: The overall shape of the movable slot (205) in the horizontal plane is one of a straight line, a cross, a circle, an ellipse, a triangle, a rectangle, a regular polygon or an irregular polygon, preferably a cross or a circle.

3. The ladle baking system according to claim 1 or 2, characterized in that: The gas blowing device (3) comprises a bottom blowing ring pipe (301), a bottom blowing branch pipe (302), a bottom air chamber (303), a porous brick (304) and a bottom blowing hole (305); the porous brick (304) is arranged at the bottom of the ladle (1), the bottom blowing air chamber (303) is arranged below the porous brick (304), the bottom blowing hole (305) is opened on the porous brick (304), and the bottom blowing air chamber (303) is connected to the bottom of the inner cavity of the ladle (1) through the bottom blowing hole (305); the bottom blowing ring pipe (301) The bottom blowing ring pipe (301) is arranged around the outer side of the bottom air chamber (303) and is connected to the bottom air chamber (303) through a bottom blowing branch pipe (302); a smoke delivery pipe (306) and a fuel gas delivery pipe (307) are connected to the air inlet of the bottom blowing ring pipe (301), and a gas valve (308) is independently arranged on the smoke delivery pipe (306) and the fuel gas delivery pipe (307); preferably, in the circumferential direction of the bottom blowing ring pipe (301), the bottom blowing ring pipe (301) is connected to the bottom air chamber (303) through a plurality of bottom blowing branch pipes (302).

4. The ladle baking system according to claim 3, characterized in that: The bottom blowing hole (305) is one or more of a circular hole, a long strip hole or a square hole; the diameter of the upper outlet of the bottom blowing hole (305) is smaller than the diameter of the lower inlet; Preferably, a plurality of bottom blowing holes (305) are provided on the porous brick (304), and the plurality of bottom blowing holes (305) are distributed on the porous brick (304) in any arrangement.

5. The ladle baking system according to any one of claims 1 to 4, characterized in that: The system also includes a spring weighing device (4), which is arranged between the gas blowing device (3) and the ground.

6. The ladle baking system according to any one of claims 1 to 5, characterized in that: The system also includes a control device (5), wherein the control device (5) is electrically connected to the mobile burner device (2) and the gas injection device (3), and the control device (5) is used to control the working states of the mobile burner device (2) and the gas injection device (3).

7. A ladle baking method or a ladle baking method using the ladle baking system according to any one of claims 1 to 6, characterized in that: The method comprises the following steps: 1) adding scrap steel into a ladle (1), and calculating a preheating coefficient for baking the ladle (1) according to the mass of the added scrap steel; 2) calculating, based on the calculated preheating coefficient, the moving speed of the burner (204), the gas flow rate supplied to the burner (204), and the gas flow rate and / or flue gas flow rate injected by the gas injection device (3) into the bottom of the inner cavity of the ladle (1) when baking the ladle (1); 3) Parameters are set based on the calculated moving speed of the burner (204), the gas flow rate supplied to the burner (204), and the gas flow rate and / or flue gas flow rate sprayed into the bottom of the inner cavity of the ladle (1) by the gas injection device (3), and the ladle (1) is baked according to the set parameters until the ladle (1) meets the requirements for holding molten steel.

8. The method according to claim 7, characterized in that: Step 1) is specifically as follows: the total mass of the scrap steel in the ladle (1) is detected by a spring weighing device (4) and recorded as W, kg; then the preheating coefficient β, kJ / mm, of the ladle (1) during baking is: β=(W*Cp*Tp) / D(I); In formula (I): Cp is the average specific heat capacity of the scrap steel, kJ / (kg·°C); Tp is the average target temperature at which the scrap steel is preheated, °C; and D is the average particle size of the scrap steel, mm.

9. The method according to claim 8, characterized in that: Step 2) is specifically as follows: when the ladle (1) is baked, the moving speed of the burner (204) is recorded as V, r / min; the flow rate of the gas supplied to the burner (204) is recorded as Q1, m 3 / min; the gas flow rate injected by the gas injection device (3) into the bottom of the inner cavity of the ladle (1) is recorded as Q2, m 3 / min; the flue gas flow rate injected by the gas injection device (3) into the bottom of the inner cavity of the ladle (1) is recorded as Q3, m 3 / min; then: V = a*β+b(II); Q1=(c*β+Cp*β) / u(III); Q2=Q 1* Z(IV); Q3 = (Cr / Cy) * Q2 (V); In formulas (II)-(V): a is the movement correction coefficient, (r·mm) / (kJ·min), with a value of 0.001-1; b is the movement correction constant, with a value of 1-50; c is the gas flow correction coefficient, kJ / (kg·℃), with a value of 0.001-1; u is the gas flow correction constant, (kJ 2 ·min) / (kg·℃·mm·m 3 ), with a value of 1000-5000; Z is the porosity of the scrap steel layer, with a value of 0.05-0.5; Cy is the calorific value of flue gas, kJ / kg; Cr is the calorific value of fuel gas, kJ / kg.

10. The method according to any one of claims 7 to 9, characterized in that: The flue gas injected into the bottom of the inner cavity of the ladle (1) by the gas injection device (3) is hot flue gas generated by the system or hot flue gas generated by other processes in the steel plant.

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