A dual layer impeller desulfurization lance that inhibits eccentric vibration and methods of using the same

Abstract

This invention relates to the field of metallurgical equipment and discloses a double-layer agitator desulfurization spray gun for suppressing eccentric vibration and its usage method. The desulfurization spray gun includes a rotating shaft, an anti-slagging agitator assembly, and a main agitator assembly. The anti-slagging agitator assembly is connected to the rotating shaft and includes multiple first agitator blades. The first agitator blades have a set geometry and installation angle, enabling them to induce forced vortices in the slag layer in the slag line region during rotation. The main agitator assembly is connected to the rotating shaft and located below the anti-slagging agitator assembly. The desulfurization spray gun of this invention, by setting the upper anti-slagging agitator assembly, induces forced vortices in the slag line region, achieving active constraint and isolation of the slag, preventing slag from contacting and adhering to the gun body, suppressing eccentric slagging from the source, and providing a prerequisite guarantee for the stable operation of the spray gun at high speed. The upper and lower double-layer agitators work together to effectively prevent desulfurizing agent residue from adhering to the blade surface and connection points.

Description

Technical Field

[0001] This invention relates to the field of metallurgical equipment, specifically to a double-layer agitator desulfurization spray gun for suppressing eccentric vibration and its application method. Background Technology

[0002] Hot metal desulfurization pretreatment is one of the key processes in modern steelmaking. Sulfur, a harmful impurity in steel, significantly reduces toughness and corrosion resistance, and affects the stability and product quality of subsequent steelmaking processes. By reducing the sulfur content in hot metal to a low level through desulfurization pretreatment, the performance of the final steel product can be effectively improved. Furthermore, it can reduce the desulfurization burden during converter or electric arc furnace steelmaking, shorten the smelting cycle, and lower overall production costs.

[0003] In the desulfurization process of molten iron pretreatment, the rotary stirring lance enhances the mixing and contact between the desulfurizing agent and molten iron through mechanical stirring, which is a key technical means to improve desulfurization efficiency. Currently, there are some known desulfurization lances with stirring paddles. For example, patent CN212270151U discloses a rotary jet desulfurization stirring lance. This lance includes a lance body, which comprises a powder spraying inner tube, a cooling medium conveying pipe, and a rotary drive shaft. A flange assembly is integrated with the rotary drive shaft. It also includes a cooling medium inlet and outlet, cooling medium, stirring blades fixed to the lower part of the rotary drive shaft, and a refractory casting layer on the rotary drive shaft and stirring blades. The cooling medium inlet is located at the upper part of the cooling medium conveying pipe via a rotary joint. A cooling medium flow hole communicating with the rotary drive shaft is opened at the lower part of the cooling medium conveying pipe. A cooling medium outlet is opened at the lower part of the flange assembly and on the rotary drive shaft, forming a cooling medium output channel between the rotary drive shaft and the cooling medium conveying pipe.

[0004] However, this type of rotary spray gun faces a fatal limitation in practical applications: eccentric vibration caused by slag buildup at the slag line. Irregular molten slag easily adheres to the spray gun at the slag line, forming nodules. This causes a significant shift between the spray gun's geometric center and its center of mass. When the spray gun rotates, the eccentric mass generates enormous centrifugal excitation force, triggering violent shaking. To prevent this violent vibration from damaging the spray gun body, refractory materials, and drive unit, existing technologies typically employ passive protective measures: limiting the spray gun's rotation speed. Operators can only control the rotation speed at a low level (e.g., below 50 rpm) to avoid equipment damage. However, theoretically, higher rotation speeds can lead to stronger turbulence and smaller desulfurizer particles, thus significantly improving desulfurization reaction kinetics and desulfurizer utilization. Therefore, this method of suppressing vibration amplitude by limiting rotation speed presents the following problems: Reduced desulfurization efficiency: Low rotation speed weakens the turbulence intensity of molten iron, resulting in uneven mixing of the desulfurizing agent and molten iron, and insufficient reaction; Decreased utilization of desulfurizing agent: The desulfurizing agent cannot be fully crushed and dispersed, and a large amount of unreacted desulfurizing agent is discharged as waste residue, resulting in increased material consumption and increased treatment costs; Extended processing time: In order to achieve the target sulfur content, the stirring time must be extended, which slows down the production pace.

[0005] Therefore, developing a spray gun structure that can suppress eccentric vibration at its source, thereby allowing the spray gun to operate stably for a long time at the designed high speed, has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] The main objective of this invention is to provide a double-layer agitator desulfurization spray gun with eccentric vibration suppression and its usage method, to solve the problem in the prior art where slag buildup and eccentricity cause reduced operating speed, thus affecting desulfurization efficiency and reagent utilization. The double-layer agitator desulfurization spray gun of this invention with eccentric vibration suppression can actively prevent slag formation, maintain a stable center of gravity, and support stable operation at high speeds.

[0007] According to the present invention, a double-layer agitator desulfurization spray gun for suppressing eccentric vibration is provided, the desulfurization spray gun comprising: Rotation axis; An anti-slagging stirring paddle assembly is connected to the rotating shaft and includes a plurality of first stirring blades, the first stirring blades having a set geometry and installation angle, so that they can induce a forced vortex in the molten slag layer in the slag line region when rotating. The main agitator assembly is connected to the rotating shaft and located below the anti-caking agitator assembly.

[0008] According to one embodiment of the present invention, the first stirring blade is inclined relative to a reference plane, the reference plane being a vertical plane defined by the axis of the rotation shaft and the midpoint of the first stirring blade in the height direction, the first stirring blade having a slag-facing surface and a slag-backing surface arranged opposite to each other, the slag-facing surface having a forward tilt angle of 3~15° relative to the reference plane, and the slag-backing surface having a forward tilt angle of 0~8° relative to the reference plane.

[0009] According to one embodiment of the present invention, the forward tilt angle of the back slag surface relative to the reference plane is 0~3°.

[0010] According to one embodiment of the present invention, the first stirring blade further has an outer surface connecting the slag-facing surface and the slag-receiving surface and located at the outer edge of the first stirring blade, the outer surface being inclined from bottom to top toward an axis away from the rotation axis, the inclination angle being 2~4°.

[0011] According to one embodiment of the present invention, the first stirring blade further has an upper surface connecting the slag-facing surface and the slag-receiving surface and located at the top of the first stirring blade, the upper surface being inclined downward relative to the horizontal surface at an angle of 0 to 20°.

[0012] According to one embodiment of the present invention, the portion of the first stirring blade connected to the rotating shaft has a smooth transition, and the transition angle is controlled between 10 and 30°.

[0013] According to one embodiment of the present invention, the height of the first stirring blade is 0.7 to 2 times the diameter of the rotating shaft, and the maximum radial dimension of the first stirring blade is 0.3 to 1 times the diameter of the rotating shaft.

[0014] According to one embodiment of the present invention, the anti-slagging stirring paddle assembly includes 2 to 4 first stirring blades evenly distributed along the circumference, wherein the first stirring blades adopt a spiral torsion streamline structure.

[0015] According to one embodiment of the present invention, the anti-slagging stirring paddle assembly includes a first stirring core plate and a refractory material layer sintered on the outer peripheral surface of the first stirring core plate.

[0016] According to another aspect of the present invention, a method for using a double-layer agitator desulfurization lance that suppresses eccentric vibration is provided. The method uses the double-layer agitator desulfurization lance that suppresses eccentric vibration according to any of the above embodiments and includes: setting the anti-slag-caking agitator assembly of the desulfurization lance 20-200 mm below the slag line interface of the molten iron ladle during desulfurization pretreatment; and after desulfurization is completed and the desulfurization lance stops rotating, keeping the anti-slag-caking agitator assembly in the molten iron to melt the slag adhering to the body of the desulfurization lance.

[0017] Compared with the prior art, the double-layer agitator desulfurization spray gun for suppressing eccentric vibration of the present invention and its method of use have at least one of the following beneficial effects: (1) By setting the upper anti-slag stirring paddle assembly, a forced vortex is induced in the slag line area to achieve active constraint and isolation of the molten slag, avoid the molten slag from contacting and adhering to the gun body, suppress the eccentric slag phenomenon from the source, and provide a prerequisite guarantee for the high-speed and stable operation of the spray gun. (2) The blades of the anti-slag stirring paddle are narrow, long, and upright with low turbulence and high shear. They are not spread at large angles and do not create strong molten iron circulation, thus avoiding the entrainment of a large amount of molten slag into the molten iron. The outer edge of the blades maintains a small distance from the surface of the gun body and sweeps strongly to form a ring-shaped cleaning zone at the slag line position. (3) The upper and lower double-layer stirring paddles work together, with the upper layer dynamically preventing slag and the lower layer efficiently stirring. While achieving stable operation at high speed, it effectively avoids the adhesion of desulfurizing agent residue on the surface of the paddle blades and the connection parts, reduces equipment maintenance costs, and extends the service life of the spray gun. (4) By comprehensively optimizing the installation angle and shape of the slag-facing surface, slag-backing surface, outer surface and transition structure, a dynamic anti-slag flow field is constructed in the slag line area, and a stable air gap / liquid slag isolation layer is formed between the gun body and the molten slag, so as to achieve non-contact anti-slag and prevent molten slag from adhering and forming nodules from the source. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic diagram of the overall structure of a double-layer agitator desulfurization spray gun for suppressing eccentric vibration according to an embodiment of the present invention is shown. Figure 2 It shows Figure 1 The cross-sectional view of the double-layer agitator desulfurization spray gun shown along line AA, which suppresses eccentric vibration. Figure 3 It shows Figure 1 The image shows a B-direction view of a double-layer agitator desulfurization spray gun designed to suppress eccentric vibration. Figure 4 It shows Figure 1 The cross-sectional view along the CC line of the double-layer agitator desulfurization spray gun that suppresses eccentric vibration is shown. Figure 5 It shows Figure 1 The cross-sectional view along line DD of the double-layer agitator desulfurization spray gun used to suppress eccentric vibration is shown. Figure 6 It shows Figure 2 The enlarged view of the double-layer agitator desulfurization spray gun used to suppress eccentric vibration is shown at point I.

[0020] List of reference numerals in the attached diagram: 100-Rotating shaft; 110-Bearing outer pipe; 111-Desulfurizing agent inlet connector; 112-Desulfurizing agent injection hole; 113-Guide hole; 120-Upper partition plate; 121-Lifting lug; 130-Upper stiffening plate; 140-Lower partition plate; 150-Lower stiffening plate; 200-Anti-slagging stirring paddle assembly; 210-First stirring blade; 220-First stirring core plate; 230-First refractory material layer; 300-Main stirring paddle assembly; 310-Second stirring blade; 311-Second stirring core plate; 312-Second sintered refractory material layer. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0022] The terms "comprising" and "having," and any variations thereof, used in the specification and accompanying drawings of this invention are intended to cover non-exclusive inclusion; the terms "first," "second," etc., used in the specification, claims, or accompanying drawings of this invention are used to distinguish different objects, not to describe a particular order. "A plurality of" means two or more, unless otherwise explicitly specified.

[0023] Furthermore, the reference to "embodiment" herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0024] One aspect of the present invention provides a double-layer agitator desulfurization spray gun for suppressing eccentric vibration. Figure 1 A schematic diagram of the overall structure of a double-layer agitator desulfurization spray gun for suppressing eccentric vibration according to an embodiment of the present invention is shown. Figure 2 It shows Figure 1 The cross-sectional view of the double-layer agitator desulfurization spray gun shown along line AA, which suppresses eccentric vibration. Figure 3 It shows Figure 1 The image shows a view along direction B of the double-layer agitator desulfurization spray gun used to suppress eccentric vibration. Figure 4 It shows Figure 1 The cross-sectional view along the CC line of the double-layer agitator desulfurization spray gun that suppresses eccentric vibration is shown. Figure 5 It shows Figure 1 The cross-sectional view along line DD of the double-layer agitator desulfurization spray gun used to suppress eccentric vibration is shown. Figure 6 It shows Figure 2The enlarged view of the double-layer agitator desulfurization spray gun used to suppress eccentric vibration is shown at point I.

[0025] like Figure 1-6 As shown, the double-layer agitator desulfurization spray gun for suppressing eccentric vibration generally includes a rotating shaft 100, an anti-slagging agitator assembly 200, and a main agitator assembly 300.

[0026] The rotating shaft 100 serves as the core support and drive transmission component of the entire spray gun. Its upper end is fixedly connected to the output end of an external rotary drive device, such as a motor or hydraulic motor, while its lower end is sequentially connected to the anti-slagging agitator assembly 200 and the main agitator assembly 300. The rotating shaft 100 not only transmits torque and bears the axial and radial loads during the spray gun's operation, but also integrates the desulfurizing agent injection channel and cooling water circulation channel to achieve injection and cooling functions. To avoid eccentric vibration caused by uneven mass distribution or fluid impact during operation, the rotating shaft 100 adopts a multi-segment combined structure and optimizes the support and counterweight design.

[0027] Specifically, the rotating shaft 100 may include a desulfurizing agent inner tube, a cooling water intermediate tube, and a load-bearing outer tube 110, which are sequentially arranged from the inside out. The central channel of the desulfurizing agent inner tube forms a desulfurizing agent injection channel, with a desulfurizing agent inlet connector 111 at its top and a desulfurizing agent injection hole 112 at its bottom. The desulfurizing agent inner tube can be a single seamless steel tube, preferably a stainless steel seamless tube. Multiple support blocks are arranged in a circumferential array along the outer wall of the desulfurizing agent tube in the circumferential direction, and multiple support blocks are arranged in a linear array along the outer wall of the desulfurizing agent tube in the axial direction; the gap between the outer side of the support block and the inner wall of the cooling water intermediate tube is 0.2~0.5mm.

[0028] A cooling water intermediate pipe is sleeved outside the desulfurizing agent inner pipe, forming a cooling water inlet chamber between them; a cooling water return chamber is formed between the cooling water intermediate pipe and the load-bearing outer pipe 110. The upper side wall of the rotating shaft 100 is provided with a cooling water inlet and a cooling water outlet, which are respectively connected to the cooling water inlet chamber and the cooling water return chamber. Cooling water flows downwards in the inlet chamber, and after reaching the bottom of the rotating shaft 100, it is deflected back through the bottom guide hole 113 into the return chamber and discharged upwards, forming a forced circulation cooling circuit. This effectively cools the rotating shaft 100 and the spray gun, reducing the heat load during spray gun operation.

[0029] The load-bearing outer tube 110 is the main load-bearing component of the rotating shaft 100, and its material is high-strength alloy steel. The upper part of the load-bearing outer tube 110 has a square or splined connecting section for connecting to the drive unit, used to transmit large torques; the middle part has a circular cross-section support section, the outer surface of which is provided with two axially spaced rolling bearing assemblies. These bearing assemblies are installed in bearing seats fixed to the top of the desulfurization reactor, thereby providing rotational freedom while limiting radial movement and suppressing eccentric vibration. The lower part of the load-bearing outer tube 110 has a connecting flange for detachably fixing to the anti-slagging agitator assembly 200.

[0030] With the above structure, the rotating shaft 100 can achieve the functions of desulfurizing agent injection and cooling, while possessing excellent bending stiffness and dynamic balance characteristics, effectively suppressing eccentric vibration and extending the overall service life of the spray gun.

[0031] The anti-slag agitator assembly 200 has a specific structural design to enable it to meet dynamic slag prevention requirements. Its blades have a specific geometry and installation angle, which allows it to induce a forced vortex in the molten slag layer in the slag line area when rotating, forming an annular cleaning zone at the slag line location.

[0032] Specifically, the upper anti-slag-caking agitator assembly 200 is connected to the rotating shaft 100 and includes a plurality of first agitator blades 210. The first agitator blades 210 have a set geometry and installation angle, so that when they rotate, they can induce a forced vortex in the slag layer in the slag line area, forming an annular cleaning zone at the slag line position.

[0033] In some embodiments of the present invention, the first stirring blade 210 is inclined relative to a reference plane, which is a vertical plane defined by the axis of the rotating shaft 100 and the midpoint of the first stirring blade 210 in the height direction (i.e., the direction parallel to the axis of the rotating shaft). The first stirring blade 210 has a slag-facing surface and a slag-backing surface arranged opposite to each other. The slag-facing surface refers to the surface of the blade that first contacts the molten slag and bears the frontal impact of the molten slag when the rotating shaft 100 drives the first stirring blade 210 to rotate in a set direction, i.e., the front side surface in the direction of blade rotation; the slag-backing surface refers to the other side surface opposite to the slag-facing surface, i.e., the rear side surface in the direction of blade rotation. This surface mainly bears the force of the negative pressure or eddy current region formed after the separation of molten iron and slag during rotation.

[0034] In some embodiments of the present invention, the forward tilt angle of the slag-facing surface relative to the reference plane is 3~15°. "Forward tilt" means that the upper end of the blade is further forward of the rotation direction than the lower end, that is, the slag-facing surface is tilted from bottom to top towards the rotation direction. This tilted posture, with the upper end leading and the lower end lagging, causes the blade to generate a downward component force on the molten iron and slag when rotating, achieving the guiding effect of pushing the slag downward and discharging it outward. The slag-facing surface adopts a 3~15° slightly forward tilt structure from bottom to top, so that the blade generates a downward component force and an outward radial thrust during rotation. This causes the slag in contact with the blade to slide along the blade surface towards the ladle wall instead of moving upward along the axial direction, thereby effectively preventing the slag from accumulating in the central area of ​​the lance. If the forward tilt angle is too small, the downward axial force is insufficient, failing to effectively push the slag contacting the blades downwards. This leads to slag accumulation on the blade surface and at the blade root, accelerating slag adhesion. Conversely, if the forward tilt angle is too large, it not only causes a sharp increase in rotational resistance and excessive axial thrust that causes the lance to sink and deviate, but also forces a large amount of slag in the molten iron to be forcibly pushed downwards into the depths of the molten iron. This results in slag being suspended or retained inside the molten iron for an extended period, leading to a significant increase in inclusions in the steel and deteriorating the steel's cleanliness. Therefore, it is necessary to control the forward tilt angle of the first stirring blade 210's slag-facing surface within a suitable range.

[0035] In some embodiments of the present invention, the forward tilt angle of the slag back surface relative to the reference plane is 0~8°, and further, the forward tilt angle of the slag back surface relative to the reference plane is 0~3°. An upright or minimally tilted slag back surface provides a higher section modulus, significantly enhancing the bending stiffness of the blade, making the blade less prone to plastic deformation or root cracking under long-term high-torque stirring conditions, thereby extending the blade's service life. Moreover, this structure of the slag back surface generates almost no inward radial force, avoiding the formation of a strong backflow vortex on the back of the blade during rotation, effectively preventing slag from being drawn into and adhering to the back of the blade.

[0036] In some embodiments of the present invention, the first stirring blade 210 further has an outer surface connecting the slag-facing surface and the slag-backing surface and located at the outer edge of the first stirring blade 210. The outer surface is inclined from bottom to top toward the axis away from the rotation axis 100, with an inclination angle of 2 to 4°. Since the outer surface has a slightly outward inclination structure along the axial direction, when the first stirring blade 210 rotates with the rotation axis 100, the radial radius at different heights of the blade gradually increases from bottom to top. Under the same angular velocity conditions, the tip linear velocity increases with the height, thereby forming a velocity gradient shear layer that gradually decreases from top to bottom near the surface of the lance body. This shear layer subjectes the molten iron and slag near the outer surface of the blade to continuous tangential shear force. Since the upper linear velocity is higher than the lower velocity, the slag is quickly peeled off once it contacts the outer surface of the blade, and cannot remain on the blade surface and gradually thicken, thereby achieving a slag-preventing effect similar to "self-cleaning". Furthermore, the slight outward inclination of the outer surface ensures that the centrifugal force generated during blade rotation has a radial component that gradually increases from bottom to top. Under the action of centrifugal force, the molten slag is actively thrown outward, preventing it from accumulating back towards the center of the spray gun. Combined with the downward pushing action of the slag-facing surface and the anti-retention design of the slag-receiving surface, the three work together: the slag-facing surface provides an axial downward pushing force, the slag-receiving surface maintains structural rigidity and does not generate reverse vortices, and the outer surface provides a radial outward throwing force. Together, they form the slag discharge path of the flow field, effectively guiding the molten slag towards the tank wall and causing it to float to the slag layer, significantly reducing the probability of molten slag accumulation on the spray gun surface.

[0037] In some embodiments of the present invention, the first stirring blade 210 further has an upper surface connecting the slag-facing surface and the slag-backing surface and located at the top of the first stirring blade 210. The upper surface is inclined downward relative to the horizontal surface at an angle of 0~20°. During rotation, the upward structure of the upper surface generates an axial upward force and a radial outward centrifugal force on the molten iron surface and the slag near the slag line. The upward force helps to lift and disperse the viscous slag deposited in the slag line area above the lance, preventing it from condensing and forming nodules on the lance surface due to the relatively low temperature; the radial centrifugal force causes the slag to be thrown away along the upper surface of the blade towards the flask wall, preventing it from gathering back towards the center area of ​​the lance. The synergistic effect of both can effectively destroy the tendency of slag to form annular nodules on the upper part of the lance, significantly reducing the difficulty and frequency of slag cleaning. The upward design of the upper surface, combined with the downward slope of the slag-facing surface and the outward slope of the outer surface, forms a synergistic slag removal system: the slag-facing surface provides an axial downward pushing force to prevent slag from accumulating in the center of the lance; the outer surface provides a radial outward throwing force to prevent slag from adhering to the sides; and the upper surface provides an axial upward dispersing force, specifically addressing the problem of slag line nodule formation. These three force paths complement each other, guiding the slag to the upper part of the lance wall and smoothly into the slag layer, preventing stubborn adhesion at any point on the lance.

[0038] In some embodiments of the present invention, the portion where the first stirring blade 210 is connected to the rotating shaft 100 has a smooth transition, with the transition angle controlled between 10 and 30°. For example, a conical transition plus a smooth arc transition can be used between the blade and the rotating shaft 100 of the spray gun, with the transition angle controlled between 10 and 30°, without right angles, grooves, or dead angles for slag adhesion, thus structurally preventing slag from accumulating and getting stuck.

[0039] In some embodiments of the present invention, the height of the first stirring blade 210 is 0.7 to 2 times the diameter of the rotating shaft 100, and the maximum radial dimension of the first stirring blade 210 is 0.3 to 1 times the diameter of the rotating shaft 100. The blade has a small height and narrow width; the height direction is only to ensure the formation of a vortex with a slag line thickness coaxial with the lance body at the slag line position, and the width direction is only to sweep the lance body surface, without participating in deep iron stirring, and without adding additional rotational load or vibration risk. The blade is generally narrow, long, and upright, with low turbulence and high shear, without large-angle expansion, and does not create strong iron circulation, avoiding the entrainment of a large amount of slag into the molten iron; the outer edge of the blade maintains a small distance from the lance body surface, strongly sweeping, forming an annular cleaning zone at the slag line position. This is significantly different from the blade design of the main stirring paddle assembly. The main agitator assembly aims to improve the mixing efficiency of molten iron and desulfurizing agent. Therefore, it needs to generate strong axial circulation and radial diffusion. The blades typically have a large area, wide width, and large tilt angle to drive the deep molten iron to form a large circulation flow, uniformly dispersing the desulfurizing agent throughout the molten iron pool, thereby accelerating the desulfurization reaction. However, the anti-slagging agitator assembly does not participate in the deep molten iron stirring and should avoid causing strong molten iron circulation, thus preventing the slag at the slag line position from being drawn downwards into the molten iron, increasing inclusions in the steel; at the same time, it should avoid increasing rotational resistance, inducing eccentric vibration, and lance deflection due to the additional large-scale circulation. By adopting a narrow, long, upright, low-turbulence, high-shear blade shape, the anti-slagging agitator only performs local sweeping cleaning of the slag line area above the lance, forming a ring-shaped cleaning zone. While ensuring the anti-slagging effect, it minimizes the additional load and interference with the main molten iron circulation, thereby ensuring the stability of the lance operation and the cleanliness of the desulfurization reaction.

[0040] In some embodiments of the present invention, the anti-slagging stirring paddle assembly 200 includes 2 to 4 first stirring blades 210 evenly distributed along the circumference. The first stirring blades 210 adopt a spiral torsion streamline structure, which has no stress concentration and no dead corners for slagging.

[0041] In some embodiments of the present invention, the anti-slagging stirring paddle assembly 200 includes a first stirring core plate 220 and a first refractory material layer 230 formed by sintering around the outer peripheral surface of the first stirring core plate 220.

[0042] The main stirring paddle assembly 300 is connected to the rotating shaft 100 and is located below the anti-slagging stirring paddle assembly 200 and close to the desulfurizing agent injection hole 112, which is immersed deep into the molten iron pool; its blades have an optimized hydrodynamic shape to generate strong radial and axial circulating flow at high speeds to break up desulfurizing agent bubbles and disperse them evenly in the molten iron.

[0043] The main stirring paddle assembly 300 may include multiple second stirring blades 310 evenly distributed circumferentially. The outer surfaces of the second stirring blades 310 are inclined outward from bottom to top, forming a "longer at the top and shorter at the bottom" structure on the iron-facing and iron-repelling surfaces of the second stirring blades 310. Based on the motion characteristic of having the same coaxial rotational angular velocity, the linear velocity is greater where the radius of the second stirring blade 310 is larger. Therefore, during the stirring process, the flow velocity of molten iron around the second stirring blade 310 increases from bottom to top along the side of the blade, making the upper circulation velocity of the second stirring blade 310 higher than the lower circulation velocity. The injected desulfurizer can enter the upper circulation region more quickly. At the same time, both the iron-facing and iron-repelling surfaces are inclined forward from bottom to top, making the side of the second stirring blade 310 have a "wider at the top and narrower at the bottom" shape, which increases the activity range of the upper circulation, improves the diffusion ability of the desulfurizer in the circumferential and radial directions, and allows the desulfurizer to enter the molten iron more quickly and evenly, enhancing the contact effect between the desulfurizer and the molten iron. In addition, this structure increases the flow rate of molten iron on the blade surface, further preventing desulfurizing agent residue from sticking and adhering between the blades.

[0044] Furthermore, the mixing blades of the upper and lower mixing heads are connected by a smooth transition, with the transition being a smooth arc transition or a hyperbola transition, in order to avoid stress concentration at the blade connection point and improve the torsional strength and service life of the mixing device blades.

[0045] Furthermore, the transition between the spray gun rotating shaft 100 and the second stirring blade 310 is a conical transition with a transition angle of 10~30°, and the angle between the upper surface of the second stirring blade 310 and the horizontal plane is 0~30°, so as to reduce slag buildup on the stirring head, reduce stress concentration, and improve the service life of the stirring device.

[0046] Furthermore, the front surface of the second stirring blade 310 has a forward tilt angle of 3~20° from bottom to top, the back surface has a forward tilt angle of 0~10° from bottom to top, and the side surface has an outward tilt angle of 2~4° from bottom to top.

[0047] The rotating shaft 100 is fixed to the connecting flange of the rotating drive device through a clamping structure, including an end flange, a clamping block designed as a lower circle with an upper part, an upper partition 120, an upper stiffening plate 130, a lower partition 140, a lower stiffening plate 150, and a lifting lug 121 welded to the upper partition 120; the circular part of the clamping block is used to bear radial force and bending moment, and the square part of the clamping block is used to bear torque.

[0048] Furthermore, the second stirring blade 310 includes a second stirring core plate 311 and a second sintered refractory material layer 312 uniformly wrapped around the outer periphery of the second stirring core plate 311. Multiple V-shaped steel bars can be welded between the outer periphery of the rotating shaft 100 and the refractory material layer, and between the outer periphery of the stirring core plate and the refractory material layer, to enhance the adhesion strength and thermal shock resistance of the refractory material layer.

[0049] Another aspect of the present invention provides a method for using a double-layer agitator desulfurization lance that suppresses eccentric vibration. The method uses a double-layer agitator desulfurization lance that suppresses eccentric vibration according to any of the above embodiments and includes the following operations: when performing desulfurization pretreatment on molten iron, the anti-slag agitator assembly 200 of the desulfurization lance is positioned 20-200 mm below the slag line interface of the molten iron ladle; after desulfurization is completed and the desulfurization lance stops rotating, the anti-slag agitator assembly 200 is kept in the molten iron to melt the slag adhering to the body of the desulfurization lance.

[0050] When the lance rotates and agitates the molten iron, the upper anti-slag stirring paddle assembly 200 rotates and drives the molten iron to generate a vortex. The rotation direction is the same as or opposite to the rotation direction of the lance body. The centrifugal force or centripetal force generated by the vortex acts on the slag, causing the slag at the slag line position to be constrained by the vortex flow field and moved away from the outer wall of the lance body. A dynamic air gap or liquid slag isolation layer is formed between the lance body and the slag, thereby avoiding direct contact and adhesion between the slag and the lance body. When desulfurization is completed and the lance stops rotating, the vortex disappears, and the position where the slag contacts the lance body gradually immerses into the molten iron. The high-temperature molten iron further melts the slag that may adhere to the lance body, preventing the slag from forming nodules on the lance body.

[0051] The present invention will be further described in detail below with reference to specific application examples, but the scope of protection of the present invention is not limited thereto.

[0052] Application Example 1: In this application example, the total length of the spray gun body is determined according to the depth of the molten iron ladle. The upper anti-slag agitator assembly 200 is located 50mm below the slag line interface, and the main agitator assembly 300 is located at the lower part of the spray gun body, immersed deep in the molten iron pool. The induced vortex rotation direction of the anti-slag agitator assembly 200 is the same as the rotation direction of the spray gun body. The first agitator blade 210 has a 9° inclination angle facing the slag, a 3° inclination angle facing the slag back, and a 3° outward inclination angle on the side. The blades are smoothly transitioned by a circular arc, the conical transition angle between the rotating shaft 100 and the blades is 20°, and the angle between the upper surface of the blade and the horizontal plane is 10°. The desulfurizer pipe is made of seamless stainless steel, and the gap between the support block and the inner wall of the cooling pipe is 0.3mm. The cooling medium is compressed air or nitrogen, which enters the input chamber through the inlet connector, enters the discharge chamber through the bottom guide hole, and is then discharged. During operation, the spray gun can reach a speed of over 120 r / min without any eccentric vibration. The desulfurization efficiency is more than 25% higher than that of traditional spray guns, the desulfurizing agent utilization rate is increased by 18%, and there is no significant slag buildup on the surface of the gun body.

[0053] Application Example 2: The difference between this application example and Application Example 1 is that the induced vortex rotation direction of the anti-slagging agitator assembly 200 is opposite to the rotation direction of the spray gun body, enhancing the centrifugal stripping effect of the molten slag; the first agitator blade 210 has a 10° inclination angle facing the slag, a 5° inclination angle facing the back iron, and a 3° outward inclination angle on the side; the blades are smoothly transitioned by a circular arc; the conical transition angle between the rotating shaft 100 and the blades is 20°; and the angle between the upper surface of the blade and the horizontal plane is 15°. After testing, after 30 heats of continuous operation, there were no obvious nodules on the surface of the spray gun, the desulfurization efficiency remained stable, and the service life of the spray gun was extended by approximately 40% compared to the traditional structure.

[0054] The above are exemplary embodiments disclosed in this invention. However, it should be noted that various changes and modifications can be made without departing from the scope of the disclosed embodiments. The functions, steps, and / or actions of the methods according to the disclosed embodiments described herein do not need to be performed in any particular order. The sequence numbers of the disclosed embodiments of this invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments. Furthermore, although the elements disclosed in the embodiments of this invention may be described or claimed individually, they may be understood as multiple unless explicitly limited to a singular number.

[0055] It should be understood that, as used herein, the singular form “a” is intended to include the plural form as well, unless the context clearly supports an exception. It should also be understood that, as used herein, “and / or” refers to any and all possible combinations of one or more of the associated listed items.

[0056] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the disclosed embodiments of the present invention is limited to these examples. Within the framework of the present invention, technical features of the above embodiments or different embodiments can also be combined, and many other variations of different aspects of the present invention as described above exist, which are not provided in detail for the sake of brevity. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A double-layer agitator desulfurization spray gun for suppressing eccentric vibration, characterized in that, include: Rotation axis (100); An anti-slagging agitator assembly (200) is connected to the rotating shaft (100) and includes a plurality of first agitator blades (210), the first agitator blades (210) having a set geometry and installation angle, which enables them to induce forced vortices in the slag layer in the slag line region when rotating. The main agitator assembly (300) is connected to the rotating shaft (100) and located below the anti-caking agitator assembly (200).

2. The double-layer agitator desulfurization spray gun for suppressing eccentric vibration according to claim 1, characterized in that, The first stirring blade (210) is inclined relative to a reference plane, which is a vertical plane defined by the axis of the rotating shaft (100) and the midpoint of the first stirring blade (210) in the height direction. The first stirring blade (210) has a slag-facing surface and a slag-backing surface arranged opposite to each other. The forward tilt angle of the slag-facing surface relative to the reference plane is 3~15°, and the forward tilt angle of the slag-backing surface relative to the reference plane is 0~8°.

3. The double-layer agitator desulfurization spray gun for suppressing eccentric vibration according to claim 2, characterized in that, The forward tilt angle of the back slag surface relative to the reference plane is 0~3°.

4. The double-layer agitator desulfurization spray gun for suppressing eccentric vibration according to claim 2, characterized in that, The first stirring blade (210) also has an outer surface that connects the slag-facing surface and the slag-receiving surface and is located at the outer edge of the first stirring blade (210). The outer surface is inclined from bottom to top toward the axis away from the rotating shaft (100) at an angle of 2 to 4°.

5. The double-layer agitator desulfurization spray gun for suppressing eccentric vibration according to claim 2, characterized in that, The first stirring blade (210) also has an upper surface that connects the slag-facing surface and the slag-receiving surface and is located at the top of the first stirring blade (210), the upper surface being inclined downward relative to the horizontal surface at an angle of 0 to 20°.

6. The double-layer agitator desulfurization spray gun for suppressing eccentric vibration according to claim 2, characterized in that, The portion of the first stirring blade (210) connected to the rotating shaft (100) has a smooth transition, with the transition angle controlled between 10 and 30°.

7. The double-layer agitator desulfurization spray gun for suppressing eccentric vibration according to claim 1, characterized in that, The height of the first stirring blade (210) is 0.7 to 2 times the diameter of the rotating shaft (100), and the maximum radial dimension of the first stirring blade (210) is 0.3 to 1 times the diameter of the rotating shaft (100).

8. The double-layer agitator desulfurization spray gun for suppressing eccentric vibration according to claim 1, characterized in that, The anti-slagging stirring paddle assembly (200) includes 2 to 4 first stirring blades (210) evenly distributed along the circumference, and the first stirring blades (210) adopt a spiral torsion streamline structure.

9. The double-layer agitator desulfurization spray gun for suppressing eccentric vibration according to claim 1, characterized in that, The anti-slagging agitator assembly (200) includes a first agitator core plate and a refractory material layer sintered around the outer periphery of the first agitator core plate.

10. A method for using a double-layer agitator desulfurization spray gun to suppress eccentric vibration, characterized in that, The method uses a double-layer agitator desulfurization lance that suppresses eccentric vibration according to any one of claims 1-9 and includes: setting the anti-slag agitator assembly (200) of the desulfurization lance 20-200 mm below the slag line interface of the molten iron ladle during the desulfurization pretreatment; after the desulfurization is completed and the desulfurization lance stops rotating, keeping the anti-slag agitator assembly (200) in the molten iron so that the slag adhering to the body of the desulfurization lance melts.

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