Device for bottom blowing of liquid metal with gas in ladle

Abstract

FIELD: metallurgy.SUBSTANCE: device for bottom blowing of liquid metal with gas in a ladle contains a seat block (1) and an inclined tuyere (2). The seat block is made inclined so that its side walls (14, 15) form an angle of 1-35° relative to its end support (9) and working (11) surfaces. Herewith, the relative thickness variation of the seat block walls does not exceed 1.30. Making the tuyere inclined allows changing the distance between the centre of the tuyere working surface and the ladle wall lining during installation of the device in the ladle bottom lining. The simultaneous manufacture of an inclined tuyere and an inclined seat block will reduce the thickness variation of the seat block walls to values at which thermal cracks do not form in them.EFFECT: increase in the reliability of the device for bottom blowing of liquid metal.4 cl, 5 dwg, 2 tbl, 1 ex

Description

[0001] The invention relates to metallurgy and can be used in the extra-furnace processing of liquid metal in a ladle by bottom blowing it with an inert gas.

[0002] A device for bottom blowing of molten metal with gas in a ladle is known, consisting of a well block and a blowing lance located within it with slotted channels and a gas supply tube (RU Patent No. 2369464, B22D 41 / 58, dated January 9, 2007). This device is installed in the bottom lining of a steel-pouring ladle, which is filled with molten metal. To conduct the secondary metalworking process, an inert gas, such as argon, is fed into the gas supply tube under a certain pressure. This gas enters the lance and moves through its slotted channels to the molten metal at the bottom of the ladle. The gas rises to the surface of the metal in the form of small bubbles, thereby causing its agitation.

[0003] The gas supply tube in this device is coaxial with the tuyere (their longitudinal axes are aligned). In such devices, the gas supply tubes exit the ladle through a layer of refractory material at the bottom of the ladle and through an opening in its steel casing (RU 2706911, B22D 41 / 58, RU 2180279, B22D 41 / 58).

[0004] The location of the device on the ladle bottom may vary, but it is generally located approximately in the middle third of the ladle bottom radius, both when installing one tuyeres CN 103114176, 2011-11-17, and when installing two tuyeres, RU 2294968C21 C 5 / 48, RU 2359781 B22D 41 / 00. It depends on many factors: the place on the ladle bottom where the liquid metal is poured from the steelmaking unit, the design of the working platform at the steelmaking unit, the grade and temperature of the steel, the chemical composition of the slag, the intensity of gas blowing, the capacity of the ladle, the smelting technology, etc. From the point of view of optimizing the smelting process, it is desirable to locate the tuyeres closer to the vertical wall of the ladle. However, closer to the refractory lining of the ladle wall, there are also more intense upward flows of liquid metal caused by the rising gas flow. This increases lining erosion.The lining wears particularly rapidly in the upper part of the ladle, where the rising metal intensively mixes the slag (JP 2018188684 and CN 104525929). For these reasons, it is often necessary to adjust the tuyere position at the bottom of the ladle to some extent. However, it is not advisable to drill additional holes in the steel ladle shell, as this is an extremely critical component of the steel-pouring ladle, subject to high mechanical and thermal loads.

[0005] Utility model CN ​​205888060 U, dated January 18, 2017, features a wedge-shaped support plate welded to the steel body of the ladle bottom. A through hole is made in the center of the wedge-shaped plate, aligned with the hole in the ladle bottom and with a permeable brick. The wedge-shaped plate, installed under the permeable brick, changes the angle of gas supply to the ladle, and the molten steel, stirred by the gas flow, evenly washes the ladle. This ensures uniform wear of the ladle lining.

[0006] The disadvantage of this design is:

[0007] 1. Due to the inclination of the gas-permeable block, one side portion, at an angle of approximately 90°, is located above the level of the refractory lining of the ladle bottom and is immersed in the liquid metal. It is known from the technical field (patent RU 173109 dated August 9, 2016) that at the protruding corners of the portion protruding into the liquid metal, thermal stresses from the horizontal and vertical planes are combined and, due to the high brittleness of the refractories, cracks often form, leading to the destruction of the well block.

[0008] 2. The wedge-shaped support plate is welded to the steel ladle shell, meaning the device has only one angle and one direction of gas injection into the molten metal. However, in practice, these parameters must be constantly adjusted depending on many factors: the location of the ladle bottom where the molten metal is poured from the steelmaking unit, the design of the steelmaking platform, the steel grade and temperature, the chemical composition of the slag, the intensity of gas flushing, the ladle capacity, the smelting technology, the grade of refractory materials used in the ladle lining, etc. For this reason, the practical application of this design is significantly limited.

[0009] 3. In Fig. 2 of the said patent, the direction of gas movement from the tuyere in the liquid metal coincides with the tuyere axis at a distance exceeding half the ladle height. This is impossible, since the specific gravity of liquid steel (7.8 g / cm 3 ), is three orders of magnitude higher than the specific gravity of argon (1.78 kg / m3 =1.78*10 -3 g / cm 3 ), which causes a very strong lifting force of the rising argon bubbles. With this ratio of specific gravities, even with an argon supply pressure of 10 atm, after exiting the tuyere crevices, the argon will begin to rise vertically after moving just a few centimeters along the tuyere axis. This is reliably confirmed in practice by the location of gases floating on the surface of the liquid metal in the ladle. Moreover, for the same reason, the gas floats on the surface of the liquid metal in the ladle in the form of a small whirlpool, rather than a wide fan, as shown in Fig. 2 of patent CN 205888060. Therefore, this patent does not correspond to real industrial processes.

[0010] 4. Obviously, for these reasons, the utility model materials do not present the results of industrial application.

[0011] Thus, based on theoretical calculations and the lack of practical confirmation, it can be concluded that this utility model is ineffective. Therefore, it cannot be classified as a gas-purging device with an inclined gas feed into molten metal.

[0012] Utility model CN ​​202380038 U, filed August 15, 2012, features an air brick inclined at an angle of 25-50 degrees relative to the axis of the vessel containing molten iron. The disadvantages of this utility model include those noted for utility model CN ​​205888060 U. Furthermore, its use for hot metal desulfurization is questionable. The temperature of hot metal from a blast furnace fluctuates around 1450°C, which is significantly lower than the temperature of liquid steel. For this reason, it is impossible to obtain a sufficiently fluid slag on its surface capable of removing sulfur to the required extent. The claimed effect in the patent materials has not been experimentally confirmed. This technical solution also cannot be classified as a device for bottom blowing of liquid metal in a ladle with an inclined gas supply.

[0013] A device for bottom blowing of liquid metal with gas in a ladle is known GB 2266361 dated 06.04.1993 (description DE4211598 dated 07.04.1992) (adopted as a prototype). It has the following disadvantages. In it, the tuyere is inclined inside the body of the well block at an angle of up to 45°. For this reason, the wall thickness in the upper part of the well block in the plane of inclination to the left and right of the tuyere has a large difference - the phenomenon of wall thickness variation (including Fig. 1, Fig. 2, Fig. 3 in the K-K plane, application No. 2024130540 RU dated 08.10.2024).

[0014] When in direct contact with the liquid metal, the top of the well block reaches its maximum temperature. Consequently, this is where the maximum thermal stresses develop. Furthermore, in the tuyere tilt plane, due to the large difference in wall thickness of the well block in the plane perpendicular to the heat flow from the liquid metal, a large difference in their linear thermal expansion occurs, increasing the overall stress in the refractory material. Considering that this thickness difference is caused by a significant reduction in wall thickness, this can lead to cracks in the top of the well block and, consequently, problems with melting.

[0015] The objective of the proposed technical solution is to increase the reliability of the device for bottom blowing of liquid metal with gas in a ladle with an inclined formula, which allows, during its installation in the lining of the bottom of the ladle, to change the distance between the center of the working surface of the tuyere and the refractory lining of the ladle wall.

[0016] The stated problem is solved by using a device comprising a well block and an inclined tuyere, wherein the well block is inclined relative to its end support and working surfaces at an angle of 1°-35°, and the relative thickness variation of its walls does not exceed 1.30. The longitudinal axes of the well block and tuyere are mutually positioned within the range from coincidence to a distance between them at any point no more than 0.5 times the diameter of the working surface of the tuyere. In this device, the inclined block may be designed as a truncated cone of the same direction as the tuyere and with a relative thickness variation of its walls along its height of no more than 1.30. In addition, signal ribs may be provided along its lateral surface in its upper portion. The longitudinal axes of the tuyere and well block may be positioned at an angle of no more than 10°.

[0017] In the proposed device, the angle of inclination of the nesting block to its end support and working surfaces is understood to be the angle of deviation from the right angle between the side surface and the working surfaces in the plane of inclination, as shown in Fig. 1, Fig. 2, Fig. 3. The axes of symmetry of the proposed device are parallel to the side surface of the nesting block, therefore this definition applies to it.

[0018] The thickness variation of the well block walls, which occurs when the tuyere is tilted, increases with the tilt angle α and is proportional to the length of the leg opposite this angle (Fig. 1, Fig. 2, application No. 2024130540 dated October 8, 2024). In a device for bottom blowing of molten metal with gas in a ladle, the pressure from the supplied gas is transmitted through the refractory material to the steel shell. In this case, the strength of the structure is ensured by the well block walls, which absorb the pressure from the shell. Therefore, thickness variation due to a decrease in the block wall thickness can significantly reduce the strength of the device.

[0019] After tilting the tuyere in the well block in Fig. 1 of the specified application, its axis moved from the DD position to the C-C position, rotating at an angle of α. The dimensions of the tuyere do not change. In this case, a right triangle was formed, in which the long leg is located on the DD axis from the lower (support) surface to the upper (working) surface of the well block (the height of the well block). The short leg is located at a right angle to it, located on the diameter of the upper working surface of the well block between the C-C and DD axes. The short leg is equal to the amount of tuyere movement on the working surface of the well block when it is tilted. In the "Example of a specific implementation" section of the application, the tuyere tilt angle is 4°, and the diameter of its working surface is 100 mm. The well block has a height of 570 mm, a diameter of 360 mm, and a wall thickness of (360-100 mm): 2 = 130 mm. The tangent of an angle of 4° is 0.07. Then the amount of movement of the upper part of the tuyere along the working surface of the well block will be 570 mm × 0.07 = 40 mm.This means that the well block wall thickness to the left of the DD axis (in the direction of tuyere tilt) will decrease by 40 mm and, correspondingly, to the right of the DD axis will increase by 40 mm. The well block wall thickness to the left of the DD axis is 130 mm - 40 mm = 90 mm, and the well block wall thickness to the right of the DD axis will be 130 mm + 40 mm = 170 mm. Thus, the wall thickness variation of the well block at α = 4° at its upper end will be:

[0020] 170mm : 90mm = 1.89

[0021] Table 1 presents similarly calculated values ​​of thickness variation for a device for blowing liquid metal with gas in a ladle of the application at inclination angles of up to 13°.

[0022]

[0023] These data show that in the design of the specified prototype application, the wall thickness variation of the well block increases rapidly with increasing inclination angle (with increasing length of the leg opposite this inclination angle). At the same time, the wall thickness of the well block on the side of the tuyere inclination decreases. With a tuyere inclination of 12°, the use of such a device is problematic due to the small wall thickness (9 mm) and large thickness variation (more than 20 times) (unacceptable thickness variation). Longitudinal cracks may appear in the thin wall, extending over a length of 40-60 mm. With a tuyere inclination angle of more than 13°, the upper part of the well block wall on the inclination side is missing (-2 mm). The use of such a device is impossible.

[0024] Thus, the boundary values ​​at which longitudinal cracks do not yet occur in the prototype design are adopted: 1) Tuyere inclination angle of 10°. 2) Tuyere movement of 100 mm. 3) Minimum wall thickness of the well block in the inclination plane of 30 mm. 4) Thickness variation of 200 mm, relative 6.67.

[0025] In addition to exposure to high temperatures, the refractory lining of the ladle bottom is subjected to maximum mechanical pressure from the column of liquid metal over the entire height of the ladle. Therefore, it must also have the highest possible strength at high temperatures. In practice, this is achieved, among other things, by selecting its most effective design parameters. The most successful refractory lining of the ladle bottom is one with a horizontal upper working surface and a lower support surface parallel to it. For such a design, the reliability of the surface on which the lower support surface rests and which also withstands the pressure of the column of liquid metal is of great importance. The steel shell of the bottom of the steel-pouring ladle, which has a different shape in different ladles, is first lined with a heat-insulating refractory material (Fig. 1, 13), on which the refractory lining is then laid (Fig. 1, 16). The upper surface of the refractory heat-insulating material (Fig.1, 13) has the most even and horizontal surface possible, which guarantees high-quality adhesion to the lower support surface of the refractory lining of the ladle bottom (Fig. 1, 10). This design of the refractory lining of the ladle bottom ensures reliable attachment to the entire lining of the ladle.

[0026] In the proposed device, the angle of inclination a of the side walls (Fig. 1, 14 and 15) of the well block (Fig. 1, 1), which determines the angle of inclination of the tuyere (Fig. 1, 2), is set relative to its end support (lower) (Fig. 1, 9) and working (upper) (Fig. 1, 11) surfaces. In order to ensure the same reliability, the end surfaces of the proposed device (Fig. 1, 9 and 11), when installed in the refractory lining of the ladle bottom (Fig. 1, 16), are fixed relative to its support (Fig. 1, 10) and working (Fig. 1, 12) surfaces. The support surface (Fig. 1, 9) is securely attached to the maximally flat and horizontal surface (Fig. 1, 13) of the heat-insulating refractory material, and the working surface (Fig. 1, 11) is aligned as closely as possible with the level of the working surface (Fig. 1, 12) of the refractory material, which prevents its chipping under thermal stress. The purpose of the proposed device is to supply gas to the molten metal at an angle away from the refractory wall of the ladle.This is achieved by tilting the tuyere (Fig. 1, 2) by tilting the nest block (Fig. 1, 1).

[0027] In this case, the position of its end surfaces (Fig. 1, 9 and 11) does not change. Fig. 1 shows the inclination of the side surfaces of pos. 14 and 15 by an angle α. Before the inclination, the axes of symmetry of the well block and the tuyere in it coincided and had a vertical position M-M. After the inclination, the well block and the tuyere retained a single axis of symmetry P-P, which also tilted by an angle a and remained in a parallel position relative to the side surfaces of pos. 14 and 15 of the well block. In this embodiment of the device for bottom blowing of molten metal with gas in the ladle, when the well block 1 is tilted, the thickness variation occurs due to the increase in the diameters of the well block from DI (before tilting) to BI and the working surface of the tuyere 2 from СЖ (before tilting) to ГЖ, located in the plane with the diameters BI and VX in Fig. 1 and Fig. 2.To simplify the design considerations, a variant has been adopted in this case in which the working surface of the well block with diameters BI and VKh, and the working surface of the tuyere with diameters GZh and UF are located in the same plane. The increase in the block wall thickness after its tilting occurs by the same amount on both sides of the I-P axis, i.e. BG = ZHI. The wall thicknesses VU and FKh remain unchanged. The diameter of the well block DI is perpendicular to the P-P axis and equal to the diameter when the block is in the vertical position. The diameter BI is the hypotenuse of triangle BID with angle α equal to the tilt angle of the well block. For the case of the "Specific Implementation Example" of the above-mentioned application (No. 2024130540 dated October 8, 2024), the diameter BI can be determined as follows.The diameter of the working surface of the tuyere СЖ=100 mm, the diameter of the well block ДИ=360 mm, and the thickness of its walls is (360 mm - 100 mm): 2=130 mm, α=4°, cos4°=0.997, diameter БИ=360 mm: 0.997=361.1 mm, the long diameter of the tuyere ГЖ=100 mm: 0.997=100.3 mm, the thickness of the walls of the well block at an angle of 4° (361.1 mm - 100.3 mm): 2=130.4 mm, the thickness variation is 130.4 mm: 130 mm=1.003. This means that the thickness variation at α=4° is practically absent. Table 2 presents the similarly calculated values ​​of thickness variation for the proposed device with the dimensions given above, within the inclination angle of up to 45° (prototype).

[0028]

[0029]

[0030] Table 2 shows that with increasing inclination angle of the well block, there is an increase in the thickness of its walls (BG and LI) in the plane perpendicular to the heat flow from the liquid metal "T" (Fig. 1, Fig. 2). Moreover, the increase in wall thickness, and accordingly the magnitude of the thickness variation, is significantly less than that of the prototype. For example, at an inclination of 10°, the thickness variation (1.5 mm, 1.01) is many times less than the thickness variation in the prototype at an inclination of 10° (200 mm, 6.67). The values ​​​​for the wall thickness of the well block and the thickness variation at an inclination of up to 45° presented in Table 2 do not lead to the formation of thermal cracks in the refractory material. In this design, the negative impact of thickness variation is largely compensated for by the absence of a factor that significantly reduces the thickness of the block. On the contrary, in contrast to the prototype, the thickness of the block walls also increases with an increase in its angle of inclination.The proposed design of a device for bottom blowing of liquid metal with gas, taking into account the individual design features of a steel-pouring ladle, has no restrictions on the angle of inclination up to 45°, since it does not have unacceptable thickness variations.

[0031] The minimum tilt angle of the well block in the proposed design is 1°. At a lower angle, the gas flow is insignificantly removed from the ladle wall and the effect of reducing the velocity of liquid metal along the surface of the ladle refractory lining is not achieved.

[0032] The maximum tilt angle of the well block was selected, in part, based on the actual dimensions of the "pit" in the refractory lining of the ladle bottom for its installation. Typically, the gap between the block and the vertical walls of the "pit" does not exceed 150 mm. This allows the block to be tilted at an angle of no more than 35°. It is also taken into account that as the tilt angle increases, the increase in the gas flow removal from the ladle wall slows down and, at approximately 30°-35°, ceases. This is due to the large difference in the specific gravities of the liquid metal and the injected gas. For this reason, the maximum tilt angle of the well block in the proposed design is 35°.

[0033] There are cases where the dimensions of the "pit" for installing the device for blowing liquid metal do not allow for the required angle of inclination of the well block. This is usually due to the various design features of the steel-pouring ladle and different options for manufacturing the lining in it. In order to increase the angle of inclination of the tuyere to an angle that ensures the required removal of the gas flow from the refractory wall of the steel-pouring ladle, the proposed design of the device for bottom blowing of liquid metal in the ladle provides for various options for the location of the tuyere in the inclined well block, Fig. 3 pos. 2, pos. 5, pos. 6. In position 2 (the tuyere is shown by a solid line), the longitudinal axes of symmetry of the tuyere and the well block coincide (axis P-P). In position 5 (the tuyere is shown by the dotted line) the tuyere is shifted parallel to the longitudinal axis of the nest block P-P in the direction of its inclination (from position P-P the tuyere axis has moved to position C-C, Fig. 3).This shift, while maintaining the tuyere inclination angle α, increases the "tuyere movement" parameter from 3Ya to 3Yu. However, this also increases the thickness variation due to a roughly equal change in the well block wall thickness. In position 6 (the tuyere is depicted as a dashed line with two dots), the tuyere is shifted by rotating its C-C axis by an angle β to the W-W axis. This leads to an increase in the "tuyere movement" parameter from point Y to point E. This also increases the thickness variation. Performing the tuyere shift using these methods separately or both together allows, in conjunction with the well block inclination, to select the most optimal "tuyere movement" value for each specific steelmaking case.To prevent unacceptable thickness variations in the proposed design, the longitudinal axes of the tuyere and well block are offset from each other, ranging from coincidence to a distance between them no greater than 0.5 times the diameter of the tuyere's working surface and a divergence angle of no more than 10°. These parameters were selected based on an analysis of data in Tables 1 and 2.

[0034] The upper working surface of the well block is in direct contact with the liquid metal and therefore has the highest temperature. The lower support surface of the well block rests on the bottom of the "pit," is furthest from the liquid metal, and therefore has the lowest temperature. As a result, a temperature gradient develops along the length of the well block, causing high thermal stresses that can lead to the formation of longitudinal cracks. These cracks extend along its entire length, from the upper working end to the lower end.

[0035] The outer surface of the prototype well block is cylindrical. Due to the conical design of the tuyere, the well block walls have different thicknesses along the height: thicker at the top (working surface), thinner at the bottom (support surface). This difference in wall thickness increases the likelihood of longitudinal crack formation. A certain portion of each of the three thermal stresses caused by the temperature difference between the top and bottom of the well block walls, the different wall thicknesses along the block height, and the tilt of the tuyere can converge in one location on the well block walls, thereby intensifying the formation of thermal cracks.

[0036] In the proposed design of a device for bottom blowing of molten metal with gas in a ladle, in order to reduce the likelihood of longitudinal cracks, a variant of an inclined well block with a minimum wall thickness variation of 7 along the height is proposed (Fig. 4). It is an inclined truncated hollow cone with a taper in the same direction as the taper of the tuyere. The wall thickness variation of such a well block along its height does not exceed 1.30 (the ratio of the maximum thickness along the height to the minimum). For example, the ratio RP to NC or the ratio SV to РЩ (Fig. 4). The optimal option is the same wall thickness of the well block along the height (the thickness variation is 1.00): RF = NC and SV = РЗ (Fig. 4).

[0037] Thus, the proposed technical solution achieves a new, unexpected technical effect, namely: the simultaneous use of an inclined tuyere and an inclined well block, the thickness difference of which does not exceed 1.30, will prevent or significantly reduce the effect of the sum of three types of thermal stresses.

[0038] The working surface area of ​​a conical well block is significantly smaller than that of a cylindrical well block. This complicates cleaning the working surface of the tuyere with oxygen using a steel pipe to remove solidified metal residues and slag in large-capacity ladles (200-450 t), where the large distance to the hot lining of the ladle bottom does not allow for a sufficiently reliable examination of the contours of the working surface of the tuyere and well block. In the proposed design of a device for bottom blowing of molten metal with gas in a ladle, longitudinal signal ribs are formed along the lateral conical surface of the well block in its upper part (Fig. 5, pos. 8). In this case, the working surfaces of the tuyere, well block, and the end surfaces of the signal ribs form a single working surface. The diameter of the circle describing it is approximately equal to the diameter of the working surface of a cylindrical well block with a tuyere of a similar size.In this design, in each specific case, some portion of this surface—usually one of the signal ribs—will not be covered by solidified metal or slag. Its visual location allows for precise determination of the tuyere's location. The signal ribs are integral structures with the well block, made of the same refractory material, decreasing the cross-section from top to bottom while simultaneously increasing the cross-section of the conical well block.

[0039] Thus, the signal ribs ensure the industrial operability of the proposed device with an inclined conical design and uniform wall thickness of the nesting block. Such a technical solution is not known in the technical field.

[0040] Example of specific implementation

[0041] The device for bottom blowing of liquid metal with gas in a ladle of the proposed design was used in a steel-pouring ladle with a capacity of 150 tons for secondary metallurgy of various steel grades. It had the following dimensions. The height of the inclined well block between the working surface and the support surface is 570 mm, the diameter in the cylindrical part perpendicular to the longitudinal axis is 360 mm. The inclination of the side walls of the well block relative to its end support and working surfaces is 4°. Tuyere: height 500 mm, diameters 200 mm and 100 mm. The longitudinal axes of the well block and the tuyere coincide. Cooler of emergency leaking metal: diameter of incomplete ring - 170 mm, height - 50 mm, tube diameter - 14 mm. Thrust washer: outer diameter - 60 mm, inner - 28 mm, thickness - 4 mm. Anchors: quantity - 4 pcs, diameter - 3 mm, length - 50 mm. Check valve diameter - 27.5 mm. The diameter of the hole in the steel casing of the bucket for threading the gas supply tube is 50 mm.Bottom insert: diameter - 230 mm, height on the tuyere inclination side - 60 mm, height on the side opposite the tuyere inclination - 92 mm. The inclination of the gas supply tube relative to the tuyere axis is 4°.

[0042] After 48 steelmaking runs, the steel-pouring ladle with the proposed argon purging device was taken out of service for slag belt repair. A simultaneous assessment of the ladle wall lining revealed uniform wear across the entire surface, including at a minimum distance from the purging device. Thus, the proposed device for bottom purging of liquid metal, with its tilted well block and tuyere, prevents additional damage to the refractory lining from liquid metal flows caused by argon bubbles rising from the tuyere. No cracks were detected on the working surface of the well block or the working surface of the tuyere. Throughout its entire operation, argon injection into the liquid metal was performed according to the specified schedule without interruption.

[0043] The prior art does not disclose a device for bottom blowing of molten metal with gas in a ladle with a well block inclined at an angle of 1°-35° relative to its end support and working surfaces, and a simultaneously inclined tuyere. This reduces the wall thickness variation of the well block to values ​​that prevent thermal cracks from forming. The prior art also does not disclose a design for an inclined conical well block, including one with signal ribs, that reduces the likelihood of longitudinal thermal cracks by reducing the wall thickness variation along its length. Therefore, this technical solution is novel.

[0044] For a person skilled in the art, it does not clearly follow from the prior art that, when the well block is tilted relative to its end and working surfaces at an angle of 1°-35° and the tuyere is simultaneously tilted, low values ​​of the thickness variation of the well block walls are ensured, at which thermal cracks do not form in them: Consequently, the proposed technical solution has an inventive step.

[0045] The industrial testing of the proposed device for bottom blowing of liquid metal with gas in a ladle has passed with a positive result and therefore the said device is industrially applicable.

Claims

1. A device for bottom blowing of liquid metal with gas in a ladle, comprising a well block and an inclined tuyere, characterized in that the well block is made with a side surface inclined relative to its end support and working surfaces at an angle of 1-35°, while the relative thickness variation of its walls does not exceed 1.

30.

2. The device according to paragraph 1, characterized in that the longitudinal axes of the tuyere and the well block are mutually located between themselves in the range from coincidence to a distance between them at any point no more than 0.5 of the diameter of the working surface of the tuyere and an angle of divergence between them of no more than 10°.

3. The device according to paragraph 1, characterized in that the inclined well block is a truncated hollow cone with a taper unidirectional with the taper of the tuyere, and with a relative difference in the thickness of its walls along the height of no more than 1.

30.

4. The device according to paragraph 3, characterized in that signal ribs are made along the side surface of the inclined socket block.

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