Multi-directional rotating hollow heating type steel ladle baking device and method

Abstract

The invention discloses a multi-directional rotating inner hollow heating type steel ladle baking device and method. The steel ladle baking device comprises a steel ladle and a multi-directional rotating baking mechanism. The multi-direction rotating baking mechanism comprises a driving supporting part, a central pipe and branch pipes. The multi-direction rotating baking mechanism is arranged at the top of the steel ladle, and the multiple strands of flames are formed in the steel scrap layer, so that the high temperature of the multiple strands of flames can be radiated to the bottom positions of different areas of the lower layer of the steel ladle for combustion, the baking uniformity of the high-temperature flames and high-temperature flue gas on the multiple areas of the steel scrap layer is enhanced, and the heat exchange efficiency is greatly improved. The problems of waste steel condensation and uneven local baking of the steel ladle are greatly relieved, and meanwhile the service life of the steel ladle furnace lining is remarkably prolonged.

Description

Technical Field

[0001] The invention relates to ladle preheating equipment and preheating technology, and in particular to a multi-directional rotating inner air heating type ladle baking device and method, belonging to the technical field of ladle preheating in 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 of poor preheating and equalization of scrap steel, poor ladle baking quality, and short service life of ladle lining in the prior art of adding scrap steel into the ladle, the present invention provides a multi-directional rotating inner air heating ladle baking device and method. The present invention arranges a multi-directional rotating baking mechanism on the top of the ladle and forms multiple flames in the scrap steel layer, so that the high temperature of the multiple flames can be radiated to the bottom position of different areas of the lower layer of the ladle for combustion, thereby enhancing the uniformity of multi-area baking of the scrap steel layer by high-temperature flames and high-temperature flue gas, and greatly improving the heat exchange efficiency. 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.

[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 multi-directional rotating inner air heating ladle baking device is provided:

[0009] A multi-directional rotating inner air heating ladle baking device, the ladle baking device comprises a ladle and a multi-directional rotating baking mechanism. The multi-directional rotating baking mechanism comprises a driving support, a central tube and a branch tube. The driving support is arranged at the top of the ladle, the top end of the central tube is connected to the driving support, and the lower end thereof extends downward into the lower part of the inner cavity of the ladle. The branch tube is arranged on the tube wall of the central tube, and the inner end of the branch tube is connected to the inner cavity of the central tube after penetrating the tube wall of the central tube. A spray hole connected to the inner cavity of the branch tube is also provided on the tube wall of the branch tube. A gas inlet is provided at the top of the central tube (for connecting to a gas transmission pipeline and then transmitting gas into the central tube), and a smoke outlet is provided on the driving support.

[0010] Preferably, the driving support part comprises a supporting cover and a main rotating lifting motor. The supporting cover is installed on the top of the ladle, the main rotating lifting motor is arranged on the surface of the supporting cover, and the supporting cover is provided with the smoke outlet. The top end of the central tube passes through the supporting cover and is connected to the main rotating lifting motor, and the central tube is driven by the main rotating lifting motor to rotate and move in the vertical direction.

[0011] Preferably, the driving support also includes a branch pipe rotation driving motor. The branch pipe rotation driving motor is arranged on the surface of the supporting cover. The inner end of the branch pipe penetrates the wall of the central pipe and is movably connected to the inner wall of the central pipe through a rotating disk. The rotating disk is connected to the branch pipe rotation driving motor through a transmission mechanism. The branch pipe rotation driving motor moves up and down in the vertical direction through the driving transmission mechanism, thereby driving the rotating disk to rotate. The rotation of the rotating disk drives the branch pipe to rotate. Preferably, the transmission mechanism is a transmission rack or a traditional belt.

[0012] Preferably, the multi-directional rotating baking mechanism comprises a plurality of branch tubes. The distribution of the plurality of branch tubes on the central tube is as follows: in the vertical direction, the central tube is provided with a plurality of circles of central tubes from top to bottom, each circle of central tubes comprises 2 or more central tubes, and any two upper and lower central tubes in any two adjacent circles of central tubes are arranged one-to-one or staggered.

[0013] Preferably, the branch pipe is provided with a plurality of spray holes. The plurality of spray holes are all located on the same side wall of the branch pipe or are distributed along the axial direction of the branch pipe in a spiral manner around the wall. Preferably, the spray hole is one of a circular hole, a conical hole, and a square hole.

[0014] Preferably, the ladle baking device further comprises a spring weighing device, and the spring weighing device is arranged at the bottom of the ladle.

[0015] Preferably, the ladle baking device further comprises a control device, which is electrically connected to the multi-directional rotating baking mechanism, and the working state of the multi-directional rotating baking mechanism 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] In the present invention, the control device has no fixed setting point, and can be set next to the baking device for control, or can be remotely controlled by a remote control room, according to the actual working conditions, as long as it can meet the control function of the baking device. 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).

[0017] According to a second embodiment of the present invention, a ladle baking method is provided:

[0018] A ladle baking method or a method for baking a ladle using the multi-directional rotating inner air heating ladle baking device described in the first embodiment, the method comprising the following steps:

[0019] 1) Add scrap steel into the ladle, and calculate the scrap steel layer height in the ladle and the preheating coefficient when baking the ladle according to the amount of scrap steel added and its particle size.

[0020] 2) The depth of the central tube into the scrap layer is calculated based on the height of the scrap layer in the ladle. The rotation speed of the central tube, the rotation speed of the branch tubes, and the gas flow rate input into the central tube when the ladle is baked are calculated based on the preheating coefficient.

[0021] 3) Parameters are set according to the depth of the central tube into the scrap steel layer, the rotation speed of the central tube, the rotation speed of the branch tube, and the gas flow rate input into the central tube, and the ladle is baked according to the set parameters until the ladle meets the requirements for receiving molten steel.

[0022] Preferably, step 1) is specifically as follows: the total mass of the scrap steel in the ladle is measured by a spring weighing device and recorded as W, kg. Then:

[0023] The height H, m, of the scrap steel layer in the ladle is:

[0024] H=W / (ρ*3.14*R 2 )(I).

[0025] The preheating coefficient β when baking the ladle, kJ / mm is:

[0026] β = (W*Cp*Tp) / D(II).

[0027] In formulas (I)-(II): ρ is the bulk density of the scrap steel, kg / m 3 R is the inner radius of the ladle, m. Cp is the average specific heat capacity of the scrap steel, kJ / (kg·℃). Tp is the average target temperature of the scrap steel to be preheated, ℃. D is the average particle size of the scrap steel, mm.

[0028] As a preferred embodiment, step 2) is specifically as follows: when the ladle is baked, the depth of the central tube into the scrap steel layer is recorded as h, m. The rotation speed of the central tube is recorded as V1, r / min. The rotation speed of the branch pipe is recorded as V2, r / min. The gas flow rate input into the central tube is recorded as Q, m 3 / min. Then:

[0029] h=λ*H (III).

[0030] V1=a*β+b (IV).

[0031] V2=c*β+d(V).

[0032] Q=f*(e*β 2 +Cp*β) / u (VI).

[0033] In formulas (III)-(VI): λ is the depth correction coefficient, which takes a value of 0.1-1. a is the first rotation correction coefficient, (r·mm) / (kJ·min), which takes a value of 0.0001-0.01. b is the first rotation correction constant, which takes a value of 0.01-1. c is the second rotation correction coefficient, (r·mm) / (kJ·min), which takes a value of 0.0001-0.01. d is the second rotation correction constant, which takes a value of 0.01-1. e is the gas flow correction coefficient, mm / (kg·℃), which takes a value of 0.001-0.1. u ​​is the gas calorific value, kJ / kg. f is the flow correction coefficient, (℃·mm·m 3 ) / (kJ·min), the value is 1.

[0034] 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).

[0035] In the present invention, a multi-directional rotating baking mechanism is provided in the ladle to achieve uniform preheating of the scrap steel inside the ladle. That is to say, the single-flame baking mode at the top of the ladle in the traditional technology is replaced by the multi-flame baking mode composed of a central tube and branch tubes through the multi-directional rotating baking mechanism. Under the action of multiple branch tubes and multiple nozzles, the top flame is divided into multiple bottom flames, allowing the flame to burn in the scrap steel layer pile, thereby enhancing the uniformity of baking multiple areas of the scrap steel layer by the high-temperature flame and high-temperature flue gas and improving the heat exchange efficiency.

[0036] In the present invention, the multi-directional rotating baking mechanism includes a driving support, a central tube and a branch tube. The driving support includes a supporting cover and a main rotating lifting motor. The supporting cover is tightly connected to the top of the ladle. The central tube is installed at the lower central position of the supporting cover and is connected to the main rotating lifting motor after passing through the supporting cover. The central tube is driven by the main rotating lifting motor to realize the lifting and lowering of the central tube in the vertical direction and the self-rotation action of rotating with its own axis. By adjusting the movement of the central tube in the vertical direction, the depth of its insertion into the scrap steel layer is adjusted to enhance the preheating effect of the lower scrap steel. At the same time, the rotation of the central tube is controlled so that the branch tube is driven to rotate through the central tube, thereby improving the preheating uniformity of the branch tube to different areas of the scrap steel layer.

[0037] In the present invention, a circle of branch pipe groups consisting of multiple branch pipes are evenly distributed in the circumferential direction of the central pipe, and in the vertical direction, multiple circles of branch pipe groups are arranged on the pipe body of the central pipe from top to bottom. The distribution of the branch pipes on the central branch pipe can be vertically arranged in a row one by one, or can be staggered in the same direction one by one. Regardless of which distribution method is used, the purpose is to improve the uniformity of the distribution of the branch pipes in the scrap steel layer, so that the gas in the central pipe is transported to the branch pipes in all directions and at all vertical heights, so as to achieve uniform preheating of the scrap steel in different material layer areas.

[0038] In the present invention, any branch pipe is provided with a plurality of spray holes, and the plurality of spray holes are distributed in a whole row along the axial direction of the branch pipe. Furthermore, a plurality of rows of spray holes can be arranged in the circumferential direction of the branch pipe. Furthermore, the plurality of rows of spray holes can be arranged in a spiral shape on the branch pipe so that the branch pipe can realize all-round flame spraying to the area where it is located, thereby improving the preheating effect of the scrap steel in the area.

[0039] In the present invention, the inner end of the branch pipe is movably connected to the central pipe through a rotating disk. The rotating disk can make the inner end of the branch pipe tightly connected to the central pipe, and can also make the branch pipe self-rotate with its axis as the rotation center. For example, the rotating disk is a bearing, whose outer ring is fixedly connected to the central pipe, and whose inner ring is fixedly connected to the branch pipe. In addition, the width of its inner ring is greater than the width of its outer ring, so that it is convenient for the part exceeding the outer ring to be connected to the transmission mechanism, so that the branch pipe rotation drive motor drives the transmission mechanism and the inner ring to rotate in turn and then drives the rotation of the branch pipe. In a preferred embodiment, the transmission mechanism is a rack vertically arranged in the central pipe, the upper end of which is connected to the branch pipe rotation drive motor after passing through the support cover, and the lower end is meshed with the protruding part of the inner ring of the rotating disk (a gear ring matching the entry). The branch pipe rotation drive motor drives the rack to move up and down periodically, and then drives the branch pipe to perform periodic forward and reverse self-rotation through the inner ring of the rotating disk. By controlling the self-rotation speed and rotation arc of the branch pipe, the flame sprayed from the branch pipe nozzle hole is made into a dynamic flame, which can enhance the uniform preheating effect of the scrap steel in each area.

[0040] In the present invention, in order to facilitate the up and down movement and self-rotation of the central tube and the self-rotation of the branch tube, the average particle size of the scrap steel added to the ladle is as small as possible. For example, the average particle size of the scrap steel is not more than 200 mm, preferably not more than 150 mm, more preferably not more than 100 mm, further preferably not more than 80 mm, and still more preferably not more than 50 mm, not more than 40 mm, not more than 30 mm, not more than 20 mm, not more than 15 mm, not more than 10 mm, not more than 8 mm, and not more than 5 mm. It can be reasonably adjusted according to actual working conditions.

[0041] In the present invention, a spring weighing device is also provided at the bottom of the ladle, the purpose of which is to accurately obtain the weight of scrap steel added into the ladle before the ladle baking operation is carried out, thereby facilitating the control device to accurately adjust the parameters of various operations to ensure baking efficiency and safe operation of the system.

[0042] In the present invention, the control device has no fixed setting point, and can be set next to the ladle 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 various parameters during ladle baking. The control device of the present invention belongs to the category of mature parameter feedback adjustment control devices, and existing products can be purchased directly from the market, and only the corresponding parameters need to be adjusted according to the working conditions.

[0043] In the present invention, when the ladle is baked by the ladle baking device or ladle baking method of the present invention, after the crushed scrap steel is added into the ladle, the spring weighing device is first used to obtain the accurate amount of scrap steel added into the ladle, W, kg. And the bulk density of the scrap steel in the ladle, and then combined with the scrap steel particle size D, mm detected in the raw material field, the height H (m) of the scrap steel layer in the ladle during this ladle baking and the preheating coefficient β (kJ / mm) are calculated. The formula is as follows:

[0044] H=W / (ρ*3.14*R 2 ) (I).

[0045] β=(W*Cp*Tp) / D (II).

[0046] In formula (I)-formula (II): ρ is the bulk density of scrap steel, kg / m 3 R is the inner radius of the ladle, m. Cp is the average specific heat capacity of the scrap steel, kJ / (kg·℃). Tp is the average target temperature of the scrap steel to be preheated, ℃. D is the average particle size of the scrap steel, mm.

[0047] After obtaining the height H of the scrap steel layer in the ladle and the preheating coefficient β, the system will calculate the depth of the central tube into the scrap steel layer during the ladle baking process based on H and β, recorded as h, m, the rotation speed of the central tube as V1, r / min, the rotation speed of the branch tube as V2, r / min, and the gas flow rate input into the central tube as Q, m 3 / min, their calculation formulas are as follows:

[0048] h=λ*H (III).

[0049] V1=a*β+b (IV).

[0050] V2=c*β+d(V).

[0051] Q=f*(e*β 2 +Cp*β) / u (VI).

[0052] In formulas (III)-(VI): λ is the depth correction coefficient, which takes a value of 0.1-1. a is the first rotation correction coefficient, (r·mm) / (kJ·min), which takes a value of 0.0001-0.01. b is the first rotation correction constant, which takes a value of 0.01-1. c is the second rotation correction coefficient, (r·mm) / (kJ·min), which takes a value of 0.0001-0.01. d is the second rotation correction constant, which takes a value of 0.01-1. e is the gas flow correction coefficient, mm / (kg·℃), which takes a value of 0.001-0.1. u ​​is the gas calorific value, kJ / kg. f is the flow correction coefficient, (℃·mm·m 3 ) / (kJ·min), the value is 1.

[0053] After obtaining the parameter values ​​of the depth h of the central tube into the scrap steel layer, the rotation speed V1 of the central tube, the rotation speed V2 of the branch tube, and the gas flow Q input into the central tube, the control device will use this as the target value to automatically adjust the main rotary lifting motor, the branch tube rotary drive motor, and the top gas valve opening until h, V1, V2, and Q in the working condition have reached the system calculated target value. The gas is input from the top of the central tube at a flow rate of Q, and the central tube rotates in the ladle at a certain speed V1, while the branch tube rotates in the ladle at a certain speed V2, ensuring that all areas in the ladle are evenly baked by the flame. 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, and conventional modifications and replacements made without departing from the technical concept of the present invention should be included in the scope of the present invention.

[0054] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0055] 1: The present invention adds a rotating baking mechanism on the top of the ladle. Through the cooperation of the double-rotating central tube and branch tubes, the high temperature of the flame can directly penetrate into the scrap steel layer while stirring the material layer, so that the preheating and heat equalization effects of the scrap steel are greatly improved compared with the traditional mode, and the problem of local cold zones caused by the low scrap steel temperature in the prior art is overcome.

[0056] 2: The high temperature of multiple flames formed by the multi-directional rotating baking mechanism of the present invention can be radiated to the bottom position of different areas of the lower layer of the ladle, that is, multiple bottom flames allow the flames to burn in different areas of the scrap steel layer, strengthen the uniformity of the high-temperature flame and high-temperature flue gas baking the scrap steel layer in multiple areas, and improve the heat exchange efficiency. 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.

[0057] 3: The present invention adopts a ladle baking device with a multi-directional rotating baking mechanism for ladle baking, which has the advantages of simple structure, easy operation, high control accuracy, excellent scrap steel equalization effect, and low investment and operation costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 It is a schematic diagram of the overall structure of the ladle baking device of the present invention.

[0059] Figure 2 It is a structural schematic diagram of the multi-directional rotating baking mechanism of the present invention.

[0060] Figure 3 It is a schematic diagram of the top view of the central tube of the present invention.

[0061] Figure 4 for Figure 3 Schematic diagram of the unfolded structure of the AA section.

[0062] Figure 5 This is a schematic diagram of the first type of spray hole opening of the branch pipe of the present invention.

[0063] Figure 6 This is a schematic diagram of the second type of spray hole of the branch pipe of the present invention.

[0064] Figure 7 for Figure 6 Schematic diagram of the structure of the BB section.

[0065] Figure 8 for Figure 6 Schematic diagram of the structure of the CC section.

[0066] Fig. 9 for Figure 6 Schematic diagram of the structure of the DD section.

[0067] Fig.10 It is a control logic flow chart of the baking method of the present invention.

[0068] Figure numerals: 1: ladle; 2: multi-directional rotating baking mechanism; 201: driving support part; 2011: supporting cover; 2012: main rotating lifting motor; 2013: branch pipe rotating driving motor; 202: center pipe; 203: branch pipe; 204: rotating disk; 205: transmission mechanism; 3: spring weighing device; 4: control device. DETAILED DESCRIPTION

[0069] 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.

[0070] A multi-directional rotating inner air heating ladle baking device, the ladle baking device comprises a ladle 1 and a multi-directional rotating baking mechanism 2. The multi-directional rotating baking mechanism 2 comprises a driving support 201, a central tube 202 and a branch pipe 203. The driving support 201 is arranged at the top of the ladle 1, the top end of the central tube 202 is connected to the driving support 201, and the lower end thereof extends downward into the lower part of the inner cavity of the ladle 1. The branch pipe 203 is arranged on the tube wall of the central tube 202, and the inner end of the branch pipe passes through the tube wall of the central tube 202 and is connected to the inner cavity of the central tube 202. A spray hole connected to the inner cavity of the branch pipe 203 is also provided on the tube wall of the branch pipe 203. A gas inlet is provided at the top end of the central tube 202, and a smoke outlet is provided on the driving support 201.

[0071] Preferably, the driving support 201 comprises a supporting cover 2011 and a main rotating lifting motor 2012. The supporting cover 2011 is installed on the top of the ladle 1, and the main rotating lifting motor 2012 is arranged on the surface of the supporting cover 2011, and the smoke outlet is opened on the supporting cover 2011. The top end of the central tube 202 passes through the supporting cover 2011 and is connected to the main rotating lifting motor 2012, and the central tube 202 is driven by the main rotating lifting motor 2012 to rotate and move in the vertical direction.

[0072] Preferably, the driving support part 201 further includes a branch pipe rotation driving motor 2013. The branch pipe rotation driving motor 2013 is arranged on the surface of the supporting cover 2011. The inner end of the branch pipe 203 penetrates the pipe wall of the central pipe 202 and is movably connected to the inner wall of the central pipe 202 through the rotating disk 204. The rotating disk 204 is connected to the branch pipe rotation driving motor 2013 through the transmission mechanism 205. The branch pipe rotation driving motor 2013 moves up and down in the vertical direction by driving the transmission mechanism 205, thereby driving the rotating disk 204 to rotate. The rotation of the rotating disk 204 drives the branch pipe 203 to rotate. Preferably, the transmission mechanism 205 is a transmission rack or a traditional belt.

[0073] Preferably, the multi-directional rotating baking mechanism 2 includes a plurality of branch pipes 203. The distribution of the plurality of branch pipes 203 on the central tube 201 is as follows: in the vertical direction, the central tube 201 is provided with a plurality of circles of central tubes 201 from top to bottom, each circle of central tubes 201 includes 2 or more central tubes 201, and any two upper and lower central tubes 201 in any two adjacent circles of central tubes 201 are provided in a one-to-one correspondence or staggered arrangement.

[0074] Preferably, the branch pipe 203 is provided with a plurality of spray holes. The plurality of spray holes are all located on the same side wall of the branch pipe 203 or are distributed along the axial direction of the branch pipe 203 in a spiral manner around the wall. Preferably, the spray hole is one of a circular hole, a conical hole, and a square hole.

[0075] Preferably, the ladle baking device further comprises a spring weighing device 3 , and the spring weighing device 3 is arranged at the bottom of the ladle 1 .

[0076] Preferably, the ladle baking device further comprises a control device 4 , which is electrically connected to the multi-directional rotating baking mechanism 2 , and the working state of the multi-directional rotating baking mechanism 2 is regulated by the control device 4 .

[0077] Example 1

[0078] like Figure 1-9 As shown, a multi-directional rotating inner air heating ladle baking device comprises a ladle 1 and a multi-directional rotating baking mechanism 2. The multi-directional rotating baking mechanism 2 comprises a driving support 201, a central tube 202 and a branch pipe 203. The driving support 201 is arranged at the top of the ladle 1, the top end of the central tube 202 is connected to the driving support 201, and the lower end thereof extends downward into the lower part of the inner cavity of the ladle 1. The branch pipe 203 is arranged on the tube wall of the central tube 202, and the inner end of the branch pipe is connected to the inner cavity of the central tube 202 after penetrating the tube wall of the central tube 202. A spray hole connected to the inner cavity of the branch pipe 203 is also provided on the tube wall of the branch pipe 203. A gas inlet is provided at the top end of the central tube 202, and a smoke outlet is provided on the driving support 201.

[0079] Example 2

[0080] Example 1 is repeated, except that the driving support part 201 includes a supporting cover 2011 and a main rotating lifting motor 2012. The supporting cover 2011 is installed on the top of the ladle 1, and the main rotating lifting motor 2012 is arranged on the surface of the supporting cover 2011, and the smoke outlet is opened on the supporting cover 2011. The top end of the central tube 202 passes through the supporting cover 2011 and is connected to the main rotating lifting motor 2012, and the central tube 202 is driven by the main rotating lifting motor 2012 to rotate and move in the vertical direction.

[0081] Example 3

[0082] The second embodiment is repeated, except that the driving support part 201 further includes a branch pipe rotation driving motor 2013. The branch pipe rotation driving motor 2013 is arranged on the surface of the supporting cover 2011. The inner end of the branch pipe 203 penetrates the wall of the central pipe 202 and is movably connected to the inner wall of the central pipe 202 through the rotating disk 204. The rotating disk 204 is connected to the branch pipe rotation driving motor 2013 through the transmission mechanism 205. The branch pipe rotation driving motor 2013 moves up and down in the vertical direction by driving the transmission mechanism 205, thereby driving the rotating disk 204 to rotate, and the rotation of the rotating disk 204 drives the branch pipe 203 to rotate.

[0083] Example 4

[0084] Example 3 is repeated, except that the transmission mechanism 205 is a traditional belt.

[0085] Example 5

[0086] Example 3 is repeated, except that the transmission mechanism 205 is a transmission rack.

[0087] Example 6

[0088] Repeat Example 5, except that the multi-directional rotating baking mechanism 2 includes a plurality of branch tubes 203. The distribution of the plurality of branch tubes 203 on the central tube 201 is specifically as follows: in the vertical direction, the central tube 201 is provided with a plurality of circles of central tubes 201 from top to bottom, each circle of central tubes 201 includes 2 or more central tubes 201, and any two upper and lower central tubes 201 in any two adjacent circles of central tubes 201 are arranged one-to-one or staggered.

[0089] Example 7

[0090] The embodiment 6 is repeated, except that a plurality of spray holes are provided on the branch pipe 203. The plurality of spray holes are all located on the same side wall of the branch pipe 203 or are distributed along the axial direction of the branch pipe 203 in a spiral manner around the wall.

[0091] Example 8

[0092] Example 7 was repeated, except that the nozzle holes were square holes.

[0093] Example 9

[0094] Example 7 was repeated except that the nozzle hole was a conical hole.

[0095] Example 10

[0096] Example 7 was repeated except that the nozzle holes were circular holes.

[0097] Embodiment 11

[0098] Example 10 is repeated, except that the ladle baking device further includes a spring weighing device 3 , and the spring weighing device 3 is arranged at the bottom of the ladle 1 .

[0099] Example 12

[0100] Example 11 is repeated, except that the ladle baking device further includes a control device 4, and the control device 4 is electrically connected to the multi-directional rotating baking mechanism 2, and the working state of the multi-directional rotating baking mechanism 2 is regulated by the control device 4.

[0101] Embodiment 13

[0102] A method for baking a ladle using the device described in Example 12, the method comprising the following steps:

[0103] 1) Adding scrap steel into the ladle 1, and calculating the height of the scrap steel layer in the ladle 1 and the preheating coefficient when baking the ladle 1 according to the amount of scrap steel added into the ladle 1 and its particle size.

[0104] 2) The depth of the central tube 202 into the scrap layer is calculated based on the height of the scrap layer in the ladle 1. The rotation speed of the central tube 202, the rotation speed of the branch tube 203, and the gas flow rate input into the central tube 202 when the ladle 1 is baked are calculated based on the preheating coefficient.

[0105] 3) Parameters are set according to the depth of the central tube 202 into the scrap steel layer, the rotation speed of the central tube 202, the rotation speed of the branch tube 203, and the gas flow rate input into the central tube 202, and the ladle 1 is baked according to the set parameters until the ladle 1 meets the requirements for holding molten steel.

[0106] Embodiment 14

[0107] Example 13 is repeated, except that step 1) is specifically as follows: the total mass of the scrap steel in the ladle 1 is detected by the spring weighing device 3 and recorded as W, kg. Then:

[0108] The height H, m, of the scrap steel layer in the ladle 1 is:

[0109] H=W / (ρ*3.14*R 2 )(I).

[0110] The preheating coefficient β, kJ / mm, for baking ladle 1 is:

[0111] β = (W*Cp*Tp) / D(II).

[0112] In formulas (I)-(II): ρ is the bulk density of the scrap steel, kg / m 3 R is the inner radius of the ladle, m. Cp is the average specific heat capacity of the scrap steel, kJ / (kg·℃). Tp is the average target temperature of the scrap steel to be preheated, ℃. D is the average particle size of the scrap steel, mm.

[0113] Embodiment 15

[0114] Example 14 was repeated, except that step 2) was specifically as follows: when the ladle 1 was baked, the depth of the central tube 202 into the scrap steel layer was recorded as h, m. The rotation speed of the central tube 202 was recorded as V1, r / min. The rotation speed of the branch tube 203 was recorded as V2, r / min. The flow rate of the gas input into the central tube 202 was recorded as Q, m 3 / min. Then:

[0115] h=λ*H (III).

[0116] V1=a*β+b (IV).

[0117] V2=c*β+d(V).

[0118] Q=f*(e*β 2 +Cp*β) / u (VI).

[0119] In formulas (III)-(VI): λ is the depth correction factor. a is the first rotation correction factor, (r·mm) / (kJ·min). b is the first rotation correction constant. c is the second rotation correction factor, (r·mm) / (kJ·min). d is the second rotation correction constant. e is the gas flow correction factor, mm / (kg·℃). u is the gas calorific value, kJ / kg. f is the flow correction factor, (℃·mm·m 3 ) / (kJ·min), the value is 1.

[0120] Method Example 1

[0121] The ladle is baked using the device described in Example 12 and the method described in Example 15: wherein: the mass of the empty ladle 1 is 40000 kg; the height of the ladle 1 is 4 m; the loading amount of the scrap steel detected by the spring weighing device 3 is 8000 kg; the average particle size D of the scrap steel is 120 mm;

[0122] The average specific heat capacity of scrap steel is Cp = 0.72 kJ / (kg·℃); the bulk density of scrap steel is ρ = 1000 kg / m 3 ; The inner radius of the ladle R = 1.5m; The target temperature of the scrap steel to be preheated Tp = 800°C; Then, according to formula (I), the height H of the scrap steel layer in the ladle 1 is calculated as:

[0123] H=W / (ρ*3.14*R 2 )=8000÷(1000×3.14×1.5×1.5)=1.13m

[0124] The preheating coefficient β when baking the ladle 1 is:

[0125] β=(W*Cp*Tp) / D=8000×0.72×800÷120=38400kJ / mm

[0126] According to the height H of the scrap steel layer in the ladle 1 and the depth correction coefficient λ=0.45 under the present working condition, the depth h of the central tube 202 into the scrap steel layer is:

[0127] h=λ*H=0.45×1.13=0.51m

[0128] According to the preheating coefficient β when the ladle 1 is baked and in this working condition, the first rotation correction coefficient a=0.0001; the first rotation correction constant b=0.05, the rotation speed V1 of the central tube 202 is:

[0129] V1=a*β+b=0.0001×38400+0.05=3.89r / min

[0130] According to the preheating coefficient β when the ladle 1 is baked and under the present working condition, the second rotation correction coefficient c=0.0003; the second rotation correction constant d=0.02, the rotation speed V2 of the branch pipe 203 is:

[0131] V2=c*β+d=0.0003×38400+0.02=11.54r / min

[0132] According to the preheating coefficient β when the ladle 1 is baked and under the present working condition, the gas flow correction coefficient e=0.001, the gas calorific value u=33000 kJ / kg, the gas flow Q input into the central tube 202 is:

[0133] Q=f*(e*β 2 +Cp*β) / u=1×(0.001×38400 2 +0.72×38400)÷33000=45.52m 3 / min.

Claims

1. A multi-directional rotating inner air heating ladle baking device, characterized in that: The ladle baking device comprises a ladle (1) and a multi-directional rotating baking mechanism (2); the multi-directional rotating baking mechanism (2) comprises a driving support part (201), a central tube (202) and a branch pipe (203); the driving support part (201) is arranged at the top of the ladle (1), the top end of the central tube (202) is connected to the driving support part (201), and the lower end of the central tube (202) extends downward into the lower part of the inner cavity of the ladle (1); the branch pipe (203) is arranged on the tube wall of the central tube (202), and the inner end of the branch pipe penetrates the tube wall of the central tube (202) and is connected to the inner cavity of the central tube (202); the tube wall of the branch pipe (203) is also provided with a spray hole connected to the inner cavity; the top end of the central tube (202) is provided with a gas inlet, and the driving support part (201) is provided with a smoke outlet.

2. The ladle baking device according to claim 1, characterized in that: The driving support part (201) comprises a supporting cover (2011) and a main rotating lifting motor (2012); the supporting cover (2011) is installed on the top of the ladle (1), the main rotating lifting motor (2012) is arranged on the surface of the supporting cover (2011), and the smoke outlet is opened on the supporting cover (2011); the top end of the central tube (202) passes through the supporting cover (2011) and is connected to the main rotating lifting motor (2012), and the central tube (202) is driven by the main rotating lifting motor (2012) to rotate and move in the vertical direction.

3. The ladle baking device according to claim 2, characterized in that: The driving support portion (201) further comprises a branch pipe rotation driving motor (2013); the branch pipe rotation driving motor (2013) is arranged on the surface of the supporting cover (2011); the inner end of the branch pipe (203) penetrates through the tube wall of the central tube (202) and is movably connected to the inner wall of the central tube (202) through a rotating disk (204); the rotating disk (204) is connected to the branch pipe rotation driving motor (2013) through a transmission mechanism (205); the branch pipe rotation driving motor (2013) moves up and down in a vertical direction through the driving transmission mechanism (205), thereby driving the rotating disk (204) to rotate, and the rotation of the rotating disk (204) drives the branch pipe (203) to rotate; preferably, the transmission mechanism (205) is a transmission rack or a traditional belt.

4. The ladle baking device according to any one of claims 1 to 3, characterized in that: The multi-directional rotating baking mechanism (2) comprises a plurality of branch tubes (203); the plurality of branch tubes (203) are distributed on the central tube (201) in the following manner: in the vertical direction, the central tube (201) is provided with a plurality of circles of central tubes (201) from top to bottom, each circle of central tubes (201) comprises two or more central tubes (201), and any two upper and lower central tubes (201) in any two adjacent circles of central tubes (201) are arranged in a one-to-one correspondence or staggered arrangement.

5. The ladle baking device according to claim 4, characterized in that: The branch pipe (203) is provided with a plurality of spray holes; the plurality of spray holes are all located on the same side wall of the branch pipe (203) or are distributed along the axial direction of the branch pipe (203) in a spiral manner around the wall; preferably, the spray hole is one of a circular hole, a conical hole, and a square hole.

6. The ladle baking device according to any one of claims 1 to 5, characterized in that: The ladle baking device also includes a spring weighing device (3), wherein the spring weighing device (3) is arranged at the bottom of the ladle (1).

7. The ladle baking device according to any one of claims 1 to 6, characterized in that: The ladle baking device also includes a control device (4), the control device (4) being electrically connected to the multi-directional rotary baking mechanism (2), and the working state of the multi-directional rotary baking mechanism (2) being regulated by the control device (4).

8. A ladle baking method or a ladle baking method using the multi-directional rotating inner air heating ladle baking device according to any one of claims 1 to 7, characterized in that: The method comprises the following steps: 1) adding scrap steel into a ladle (1), and calculating the height of the scrap steel layer in the ladle (1) and the preheating coefficient when baking the ladle (1) according to the amount of scrap steel added into the ladle (1) and its particle size; 2) calculating the depth of the central tube (202) penetrating into the scrap steel layer according to the height of the scrap steel layer in the ladle (1); calculating the rotation speed of the central tube (202), the rotation speed of the branch tube (203) and the flow rate of the gas input into the central tube (202) when the ladle (1) is baked according to the preheating coefficient; 3) Parameters are set according to the depth of the central tube (202) into the scrap steel layer, the rotation speed of the central tube (202), the rotation speed of the branch tube (203), and the flow rate of the gas input into the central tube (202), and the ladle (1) is baked according to the set parameters until the ladle (1) meets the requirements for receiving molten steel.

9. The method according to claim 8, characterized in that: Step 1) is specifically as follows: the total mass of the scrap steel in the ladle (1) is measured by a spring weighing device (3) and recorded as W, kg; then: The height H, m, of the scrap layer in the ladle (1) is: H=W / (ρ*3.14*R 2 (I); The preheating coefficient β, kJ / mm, for baking the ladle (1) is: β=(W*Cp*Tp) / D(II); In formulas (I)-(II): ρ is the bulk density of the scrap steel, kg / m 3 ; R is the inner radius of the ladle, m; Cp is the average specific heat capacity of the scrap steel, kJ / (kg·℃); Tp is the average target temperature of the scrap steel for preheating, ℃; D is the average particle size of the scrap steel, mm.

10. The method according to claim 9, characterized in that: Step 2) is specifically as follows: when the ladle (1) is baked, the depth of the central tube (202) penetrating into the scrap steel layer is recorded as h, m; the rotation speed of the central tube (202) is recorded as V1, r / min; the rotation speed of the branch tube (203) is recorded as V2, r / min; the gas flow rate input into the central tube (202) is recorded as Q, m 3 / min; then: h = λ*H(III); V1=a*β+b(IV); V2=c*β+d(V); Q=f*(e*β 2 +Cp*β) / u(VI); In formulas (III)-(VI): λ is the depth correction coefficient, which is 0.1-1; a is the first rotation correction coefficient, (r·mm) / (kJ·min), which is 0.0001-0.01; b is the first rotation correction constant, which is 0.01-1; c is the second rotation correction coefficient, (r·mm) / (kJ·min), with a value of 0.0001-0.01; d is the second rotation correction constant, with a value of 0.01-1; e is the gas flow correction coefficient, mm / (kg·℃), with a value of 0.001-0.1; u is the gas calorific value, kJ / kg; f is the flow correction coefficient, (℃·mm·m 3 ) / (kJ·min), the value is 1.

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