LF furnace with both deep desulfurization and efficient carbon addition functions

Abstract

The application relates to the technical field of steel metallurgical furnace refining, and discloses an LF furnace with deep desulfurization and efficient carbon-increasing functions, which comprises a furnace cover, an electrode lifting column and a graphite electrode, the electrode lifting column passes through the furnace cover and is fixed at the bottom end with the graphite electrode, further comprises a telescopic shielding sleeve, a rotating tooth, a first connecting rod, a rack, and a pressure storage cavity; the telescopic shielding sleeve is fixed at the electrode passing hole at the bottom of the furnace cover; the rotating tooth is movably sleeved on the upper end of the electrode lifting column, and the outer surface of the electrode lifting column and the inner side of the rotating tooth are provided with matched threads, so that the electrode lifting column drives the rotating tooth to rotate when the electrode lifting column is lifted or lowered. The telescopic shielding sleeve is arranged, and after the electrode is lowered to a heating position, the telescopic shielding sleeve is automatically unfolded to cover the side surface of the graphite electrode, so that the strong stirring of the large-flow bottom blowing required for desulfurization cannot cause the molten steel to contact the electrode body, the unexpected carbon-increasing path is physically isolated, and deep desulfurization is realized in a single LF station.

Description

Technical Field

[0001] This invention relates to the field of ladle refining technology in iron and steel metallurgy, specifically to an LF furnace that combines deep desulfurization and high-efficiency carbonization. Background Technology

[0002] The LF furnace (ladle refining furnace) is a key piece of equipment in modern steel production used for ladle refining, undertaking multiple metallurgical tasks such as desulfurization, temperature control, alloying, carbon increase, and improving the purity of molten steel. Deep desulfurization is a core requirement for producing high-quality clean steel, typically achieved through high-basicity reducing slag combined with bottom-blown argon for strong stirring. The desulfurization reaction occurs at the slag-steel interface, requiring favorable stirring kinetics to promote mass transfer. Carbon increase control is equally crucial, especially for pipeline steel and deep-drawing steel, which have strict carbon content requirements; precise control of carbon content directly determines the product grade. In conventional LF furnace refining processes, graphite electrodes are used for heating, operated through a short-arc, high-current process.

[0003] Because bottom-blown argon agitation causes fluctuations in the molten steel surface, the molten steel easily comes into direct contact with the graphite electrodes, leading to carbon diffusion from the electrodes into the molten steel and resulting in unintended carbon enrichment. Desulfurization requires thorough agitation to obtain favorable slag-steel reaction kinetics, but intense agitation can exacerbate electrode carbon enrichment. This technical contradiction constitutes the core challenge of LF furnace refining. Existing technologies still face significant difficulties in simultaneously achieving deep desulfurization and precise carbon enrichment control. Solutions relying on multi-station joint operations involve large investments and long processes; single-station process control solutions are insufficient to completely eliminate unintended carbon enrichment under ultra-low sulfur requirements, or have overly stringent operating conditions. Summary of the Invention

[0004] In view of the shortcomings of existing LF furnace refining equipment mentioned in the background art, such as the contradiction between desulfurization stirring and electrode carbonization during use, the present invention provides an LF furnace that has both deep desulfurization and high-efficiency carbonization functions. It has the advantages of physical isolation of unintended carbonization in a single station and independent and controllable deep carbonization, thus solving the technical problems mentioned in the background art.

[0005] This invention provides the following technical solution: an LF furnace with both deep desulfurization and high-efficiency carbon enhancement functions, including a furnace cover, an electrode lifting column, and a graphite electrode. The electrode lifting column passes through the furnace cover and the graphite electrode is fixed at its bottom end. It also includes a retractable shielding sleeve, a rotating tooth, a first connecting rod, a toothed rod, and a pressure accumulator. The retractable shielding sleeve is fixed to the electrode through-hole at the bottom of the furnace cover and sleeved around the graphite electrode. The rotating tooth is movably sleeved on the upper end of the electrode lifting column, and the outer surface of the electrode lifting column and the inner side of the rotating tooth are provided with matching threads, so that the rotating tooth is driven to rotate when the electrode lifting column is raised or lowered. The upper end of the first connecting rod is fixedly connected to the rotating tooth, and the lower end is fixedly connected to the top of the movable inner layer of the retractable shielding sleeve to drive the retractable shielding sleeve to extend or retract. The toothed rod meshes with the outer teeth of the rotating tooth and is driven to move horizontally when the rotating tooth rotates. The pressure accumulator is fixed to the top of the furnace cover and has a movable... The furnace is equipped with a pressure-accumulating piston, which is fixedly connected to one end of a gear rod. An air inlet pipe is connected to the outside of the pressure-accumulating chamber, and a one-way valve is installed at the air inlet pipe. The furnace also includes a carbon powder ejector, a quick-release disc spring, and a trigger pin. The carbon powder ejector is rotatably mounted at the nozzle passage of the furnace cover via a spherical rotary valve and a spring seat rod. The internal channel of the spherical rotary valve connects the pressure-accumulating chamber and the carbon powder ejector, and a one-way valve is installed within this channel. The quick-release disc spring is mounted on the spring seat rod, and one end acts on the spherical rotary valve, causing it to swing downwards. The trigger pin is located on the outer wall of the spherical rotary valve. In the non-working state, the trigger pin is engaged at a limit position on the inner wall of the pressure-accumulating chamber, keeping the quick-release disc spring charged and the spherical rotary valve closed. When the pressure-accumulating piston moves towards the trigger pin under the push of the gear rod, it can contact the trigger pin to release the limit, causing the quick-release disc spring to drive the spherical rotary valve to swing open, and the carbon powder ejector is ejected.

[0006] Preferably, the retractable shielding sleeve is composed of at least two nested heat-resistant thin-walled round tubes. The outermost sleeve is fixed to the electrode passage hole in the furnace cover, and the inner sleeves are fitted together by threaded grooves. The lower end of the first connecting rod is fixedly connected to the top end of the innermost movable sleeve. When the first connecting rod rotates, it drives the inner sleeve to rotate and extend.

[0007] Preferably, the first link is an adjustable link.

[0008] Preferably, it also includes a linkage housing, which covers the outside of the rotating teeth and the toothed rod and is fixed to the top of the furnace cover.

[0009] Preferably, the accumulator piston is fixedly connected to one end of the rack via an adjustable-length connecting rod.

[0010] Preferably, the one-way valve at the connection between the intake pipe and the accumulator chamber allows gas and toner to enter the accumulator chamber unidirectionally from the intake pipe.

[0011] Preferably, the front outlet of the carbon powder ejector tube is a converging nozzle.

[0012] Preferably, the one-way valve in the internal channel of the spherical rotary valve allows fluid to flow unidirectionally from the accumulator chamber to the carbon powder ejector.

[0013] Preferably, it also includes a reset mechanism, which includes a reset tooth disposed on the spring seat rod and a one-way toothed rod disposed on the toothed rod. When the toothed rod pulls the accumulator piston outward, the one-way toothed rod meshes with the reset tooth to drive the ball rotary valve and the carbon powder ejector to reset.

[0014] Preferably, the retractable shielding sleeve is made of silicon nitride bonded to silicon carbide.

[0015] The present invention has the following beneficial effects: 1. This invention, by setting a retractable shielding sleeve and automatically unfolding to cover the side of the graphite electrode after the electrode descends to the heating position, can prevent the large-flow bottom blowing and strong stirring required for desulfurization from causing the molten steel to come into contact with the electrode body, fundamentally physically isolating the unintended carbonization path, thereby achieving worry-free deep desulfurization in a single LF station.

[0016] 2. This invention links the accumulator chamber, the accumulator piston, and the gear rod, and uses the lifting motion of the electrode lifting column to compress the pre-inhaled carbon powder and inert gas to form a high-pressure mixture. This allows the carbon powder to penetrate the slag layer and be injected deep into the molten steel in the form of a high-speed jet, avoiding slag layer entrainment and arc zone burn-off, improving carbon recovery rate and achieving precise quantitative carbon addition.

[0017] 3. This invention uses a rotating gear to simultaneously mesh with the first connecting rod and the rack, synchronously transmitting the single power for electrode lifting and lowering to the extension and retraction of the retractable shielding sleeve and the intake and exhaust of the accumulator piston. This allows the electrode shielding protection and carbon powder accumulator injection functions to be completed entirely by the lifting and lowering motion of the same column through pure mechanical linkage, without the need for additional electrical or hydraulic drives.

[0018] 4. This invention uses a retractable shielding sleeve made of silicon nitride and silicon carbide to cover the electrode, which can withstand high temperature and steel slag corrosion in the arc heating area for a long time. This avoids the sleeve from softening, deforming or melting under frequent expansion and contraction and strong stirring and splashing conditions, thus extending the service life of the shielding device and ensuring the reliability of continuous operation.

[0019] 5. This invention uses a spherical rotary valve in conjunction with a fast-release disc spring and a trigger pin to store energy triggering structure. This structure can instantly release elastic potential energy when the pressure-accumulating piston reaches the end of its stroke, which will quickly eject the carbon powder ejector to the injection position. This allows the nozzle to avoid slag surface interference and be accurately positioned in a very short time, ensuring the penetration power of the high-pressure carbon powder jet into the slag layer and the success rate of carbonization.

[0020] 6. This invention drives the carbon powder ejector to automatically retract to the safe position of the furnace cover by meshing the unidirectional toothed rod and the reset tooth during the outward pull stroke of the toothed rod. This allows the reset action after injection to be synchronized with the carbon powder intake action of the next cycle, without the need for manual intervention or additional reset drive. This simplifies the operation process and eliminates the risk of the nozzle being burned by steel slag when the electrode arc is ignited. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic cross-sectional view of the retractable shielding sleeve structure of the present invention; Figure 3 This is a schematic cross-sectional view of the linkage structure of the present invention; Figure 4 This is a partial schematic diagram of the spherical rotary valve structure of the present invention.

[0022] In the diagram: 1. Furnace cover; 2. Electrode lifting column; 21. Graphite electrode; 3. Telescopic shielding sleeve; 31. Rotary gear; 311. First connecting rod; 32. Gear rack; 33. Linkage housing; 4. Accumulator chamber; 41. Accumulator piston; 42. Inlet pipe; 5. Carbon powder ejector; 51. Spherical rotary valve; 521. Quick release disc spring; 522. Trigger pin; 53. Spring seat rod. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] This embodiment provides an LF furnace refining device that combines deep desulfurization and efficient carbon enrichment. By modifying the refining station of a traditional LF furnace, this device adds a purely mechanically linked shielding and injection integrated mechanism to the existing electrode lifting system and furnace cover structure. This fundamentally solves the problem of unexpected carbon enrichment caused by strong stirring during desulfurization, while simultaneously achieving precise and controllable deep carbon enrichment.

[0025] Please see Figure 1An electrode passage hole is provided in the center of the furnace cover 1, through which the electrode lifting column 2 moves. A graphite electrode 21 is fixedly installed at its bottom. A retractable shielding sleeve 3 is fixedly installed at the bottom of the furnace cover 1, located around the electrode passage hole. This sleeve is movably fitted around the graphite electrode 21 and employs a multi-section, nested, heat-resistant, thin-walled circular tube structure. In this embodiment, it consists of three nested sections. The outermost sleeve is fixed at the electrode passage hole of the furnace cover and remains stationary; the middle and inner sections can rotate freely along the axial direction and are equipped with threaded lifting grooves inside, allowing for sequential extension or retraction through relative rotation.

[0026] The upper end of the electrode lifting column 2, located at the top of the furnace cover 1, is movably fitted with a rotating tooth 31. The inner side of the rotating tooth 31 and the outer side of the column 2 are provided with matching threads and grooves. When the column 2 moves up and down, it drives the rotating tooth 31 to rotate in both directions along its own axis. A first connecting rod 311 is fixedly connected to the bottom of the rotating tooth 31. The first connecting rod 311 passes downwards through the electrode through-hole to the bottom of the furnace cover 1, and its other end is fixedly connected to the top of the innermost movable sleeve of the retractable shielding sleeve 3. Thus, the lifting motion of the column 2 is converted into the rotational motion of the rotating tooth 31, which, through the first connecting rod 311, drives the middle section and inner section of the sleeve 3 to rotate synchronously, realizing the vertical extension and retraction of the sleeve 3.

[0027] The first connecting rod 311 is configured as a length-adjustable connecting rod. For example, it adopts a sleeve adjustment structure with positive and negative threads at both ends. By rotating the middle sleeve, the total length of the connecting rod can be changed, thereby adjusting the correspondence between the extension and retraction stroke of the shielding sleeve 3 and the lifting and lowering stroke of the electrode, so as to adapt to different specifications of electrode length and furnace size.

[0028] Please see Figure 2 The rotating gear 31 has teeth on its outer side, which engage with the toothed rod 32. A linkage housing 33 is fixedly installed on the outer sides of both the rotating gear 31 and the toothed rod 32. The linkage housing 33 restricts the movement trajectory of both and provides a sealing protection, preventing environmental dust pollution from affecting service life. When the electrode lifting column 2 moves up and down, it drives the rotating gear 31 to rotate in both directions, which in turn drives the toothed rod 32 to move back and forth horizontally. A nozzle through-hole is provided on the furnace cover 1 near the electrode hole. A spherical rotary valve 51 is installed at this hole. Spring seat rods 53 are installed at both ends of the spherical rotary valve 51, and the valve is rotatably supported on the furnace cover by the spring seat rods 53.

[0029] A carbon powder ejector tube 5 is fixedly installed at the bottom of the spherical rotary valve 51. The carbon powder ejector tube 5 is a slender, small-diameter refractory nozzle, whose root is fixedly connected to the valve 51 and arranged perpendicularly to the axis of the valve 51. The nozzle tip is machined into a converging nozzle to accelerate the carbon powder jet and improve its ability to penetrate the slag layer. A pressure accumulator 4 is fixedly installed at the top of the furnace cover 1, located at the nozzle through hole. The pressure accumulator 4 is a pressure-resistant container, with an air inlet pipe 42 fixedly connected to its outer side, and a one-way valve is provided at the connection point. The connection direction is from the air inlet pipe 42 to the pressure accumulator 4. A pressure accumulator piston 41 is movably installed inside the pressure accumulator 4. One side of the pressure accumulator piston 41 is fixedly connected to one end of the toothed rod 32. When the electrode lifting column 2 is lowered, the toothed rod 32 is pulled outward by linkage to pull the pressure accumulator piston 41, which increases the volume of the pressure accumulator 4 and forms a negative pressure, drawing in a certain amount of carbon powder and inert gas mixture through the air inlet pipe 42.

[0030] The spherical rotary valve 51 has a one-way valve inside, with the communication direction from the accumulator chamber 4 to the nozzle of the carbon powder ejector 5. A quick-release disc spring 521 is fixedly installed at the spring seat rod 53. A trigger pin 522 is fixedly installed on the outer wall of the spherical rotary valve 51. In the non-operating state, the trigger pin 522 is engaged at the pop-out limit position on the inner wall of the accumulator chamber 4. At this time, the quick-release disc spring 521 is in a compressed energy storage state, the spherical rotary valve 51 remains closed, and the carbon powder ejector 5 retracts upward and is in a safe position against the furnace cover.

[0031] As the electrode lifting column 2 descends, the graphite electrode 21 gradually approaches the molten steel surface. During the initial linear idle stroke of the column 2's descent, the sleeve 3 remains in a retracted state. Once the electrode 21 reaches the heating position, the column 2 continues to descend, its external thread engaging with the rotating gear 31, driving the gear 31 to rotate. The rotation of the gear 31 generates two synchronous actions: the first connecting rod 311 drives the retractable shielding sleeve 3 to unscrew section by section, completely covering and shielding the side of the graphite electrode 21; the gear engagement drives the toothed rod 32 to move horizontally outward, pulling the pressure accumulator piston 41 outward, creating a negative pressure in the pressure accumulator chamber 4, which draws in a preset amount of carbon powder and inert gas through the inlet pipe 42. At this point, a high-flow-rate bottom-blowing argon gas strong stirring desulfurization operation can be performed without any concerns. The churning molten steel and splashing high-alkalinity slag only contact the refractory surface of the sleeve 3, completely physically isolating them from the graphite electrode 21 body.

[0032] After desulfurization meets the standards, the electrode lifting column 2 rises. The upward movement of column 2 drives the rotating gear 31 to rotate in the opposite direction, which in turn drives the toothed rod 32 to advance horizontally inward, pushing the accumulator piston 41 to compress the gas and carbon powder in the accumulator chamber 4, forming a high-pressure mixed gas. When the accumulator piston 41 advances to the position of the trigger pin 522, the piston 41 presses against the trigger pin 522, causing it to disengage from the ejection limit position. The elastic potential energy stored in the rapidly released disc spring 521 is released instantly, driving the spherical rotary valve 51 to swing rapidly downward around the spring seat rod 53, ejecting the carbon powder ejector tube 5 to the preset injection position, with the nozzle precisely pointing deep into the molten steel below the slag surface. At the same time, the spherical rotary valve 51 opens with the swing, and the high-pressure carbon powder and inert gas mixture in the accumulator chamber 4 passes through the one-way valve, the internal channel of the spherical rotary valve 51, and the carbon powder ejector tube 5, penetrating the slag layer and injecting it into the molten steel in the form of a high-speed jet, completing deep and efficient carbonization.

[0033] A reset tooth is provided at spring seat rod 53. During the next working cycle, as column 2 descends again, driving rack 32 to pull the accumulator piston 41 outward, rack 32 pulls the reset tooth via a one-way rack, causing the spherical rotary valve 51 and carbon powder ejector 5 to rotate in the opposite direction, resetting them to a safe position close to the furnace cover. The one-way rack design ensures that the reset tooth is only driven when the accumulator piston 41 is pulled outward, and will not be accidentally triggered during the accumulator advance. At this point, a complete working cycle ends, the unit returns to its initial state, and is ready for the next refining operation.

[0034] The method of using (working principle) of this invention is as follows: During operation, after the molten steel ladle enters the refining station of the LF furnace, the electrode lifting column 2 drives the graphite electrode 21 to a high-position standby state. At this time, the retractable shielding sleeve 3 is in a retracted and stacked state, attached to the outer periphery of the electrode passage hole at the bottom of the furnace cover 1. The rotating gear 31, the first connecting rod 311, and the gear 32 are all in their initial positions. The linkage housing 33 forms a closed protection for the rotating gear 31 and the gear 32.

[0035] The accumulator piston 41 in the accumulator chamber 4 is in its initial position near the inlet pipe 42. The carbon powder ejector 5 retracts upwards and rests against the furnace cover 1 in a safe position. The spherical rotary valve 51 is in the closed state, and the trigger pin 522 is engaged at the ejection limit position on the inner wall of the accumulator chamber 4, rapidly releasing the coil spring 521 into a compressed energy storage state. The inlet pipe 42 is connected to an external source of carbon powder and inert gas mixture.

[0036] The electrode lifting column 2 begins to descend, and the graphite electrode 21 gradually approaches the surface of the molten steel. In the initial stage of the descent of the column 2, its outer surface is a straight, unthreaded section. Therefore, the rotating gear 31 has not yet been driven to rotate, and the retractable shielding sleeve 3 remains in a retracted state. The graphite electrode 21 smoothly passes through the inner hole of the sleeve 3 and reaches the heating arc initiation position.

[0037] After the graphite electrode 21 reaches the heating station and is energized to start the arc, the column 2 continues to descend, and its external thread section engages with the inner thread groove of the rotating tooth 31, driving the rotating tooth 31 to rotate in the positive direction along its own axis.

[0038] The rotation of gear 31 generates two synchronized actions: Firstly, the first connecting rod 311 at the bottom of the rotating gear 31 rotates along with it. The lower end of the first connecting rod 311 is fixedly connected to the top of the innermost movable sleeve of the telescopic shielding sleeve 3, driving the inner sleeve to rotate. Since each section of the sleeve has a threaded spiral groove inside, the rotation of the inner sleeve drives the intermediate section and the inner section to extend outwards axially section by section, physically covering the graphite electrode 21 from the lower end of the chuck to the side of the electrode tip. The telescopic shielding sleeve 3 is made of silicon nitride combined with silicon carbide material, which can withstand the high temperature of the arc heating area and the corrosion of steel slag.

[0039] Secondly, the meshing of the outer teeth of the rotating gear 31 drives the rack 32 to move outward in the horizontal direction. The end of the rack 32 is fixedly connected to the accumulator piston 41, which drives the accumulator piston 41 to move outward in the accumulator chamber 4, increasing the volume of the accumulator chamber 4 and creating a negative pressure. Under the action of negative pressure, the one-way valve at the air inlet pipe 42 opens, and the pre-set mixture of carbon powder and inert gas is drawn into the accumulator chamber 4 through the air inlet pipe 42, completing the quantitative filling of carbon powder. At this point, the graphite electrode 21 is tightly covered by the retractable shielding sleeve 3, the quantitative intake of carbon powder in the accumulator chamber 4 is completed, and the device enters the desulfurization operation preparation state.

[0040] Operators can activate the bottom-blowing argon system to provide strong stirring with a high flow rate of argon, creating optimal slag-steel reaction kinetics. This promotes the full reaction of sulfur in the molten steel with CaO in the high-basicity refining slag to generate CaS, which then enters the slag phase, achieving deep desulfurization. Because the sides of the graphite electrode 21 are fully physically covered by the retractable shielding sleeve 3, the violent turbulence and splashing slag caused by the strong bottom-blowing stirring only contact the refractory surface of the sleeve and cannot come into contact with the graphite electrode 21 itself. The physical path of electrode carbonization is completely cut off. Therefore, operators can apply a stronger bottom-blowing stirring intensity than conventional processes without hesitation, maximizing desulfurization efficiency and rapidly bringing the sulfur content of the molten steel to the target level without any unintended carbonization.

[0041] After the deep desulfurization meets the standards, the electrode lifting column 2 begins to rise, causing the graphite electrode 21 to leave the molten steel surface. As the column 2 moves upward, its external thread drives the rotating gear 31 to rotate in the opposite direction along its own axis. The reverse rotation of the rotating gear 31 simultaneously triggers two linked actions: First, the inner sleeve of the retractable shielding sleeve 3 is driven to rotate in the opposite direction by the first connecting rod 311, so that the middle section and the inner section are screwed in and retracted one by one, gradually removing the covering of the graphite electrode 21 without affecting the normal lifting and arc starting operation of the subsequent electrode.

[0042] Second, the outer teeth drive the rack 32 to advance inward in the horizontal direction. The end of the rack 32 pushes the accumulator piston 41 into the accumulator chamber 4, compressing the previously drawn-in carbon powder and inert gas mixture, forming a high pressure in the accumulator chamber 4.

[0043] As the accumulator piston 41 continues to advance inward, the pressure of the gas and carbon powder inside the chamber continuously increases. When the accumulator piston 41 reaches the end of its stroke, its end face presses against the trigger pin 522, causing the trigger pin 522 to disengage from the ejection limit position on the inner wall of the accumulator chamber 4. Once the trigger pin 522 disengages, the elastic potential energy stored in the rapid release disc spring 521 is released instantaneously, driving the spring seat rod 53 to cause the spherical rotary valve 51 to swing rapidly downward around its axis. When the spherical rotary valve 51 swings into position, it ejects the carbon powder ejector cylinder 5, which is fixedly connected to its bottom, downward to the preset injection working position, with the nozzle precisely pointing deep into the molten steel below the slag surface.

[0044] Simultaneously, the spherical rotary valve 51 opens its internal channel with its swinging motion. The high-pressure mixed gas pre-accumulated in the accumulator chamber 4 carries carbon powder, which is ejected in a high-speed jet form from the converging nozzle at the front end of the carbon powder ejector tube 5 through the one-way valve and channel inside the spherical rotary valve 51. The carbon powder jet, due to its high pressure and high speed, directly penetrates the slag layer and injects deep into the molten steel. The carbon powder dissolves and diffuses deep within the molten steel, rapidly dissolving using the static pressure and high temperature of the steel, while bottom-blown argon gas agitates and assists in the uniform diffusion of carbon. Because the carbon powder addition path completely avoids the surface slag layer and the arc zone, it is unaffected by slag layer entrainment and oxidation loss, resulting in a high and stable carbon recovery rate, achieving precise and controllable high-efficiency deep carbonization.

[0045] After toner injection is completed, the electrode lifting column 2 enters the next round of descent, driving the rotating gear 31 to rotate forward, which in turn drives the toothed rod 32 to pull the accumulator piston 41 outward again, initiating a new round of toner intake. During the outward pull of the toothed rod 32, the one-way toothed rod on its side engages with the reset tooth located at the spring seat rod 53, causing the spherical rotary valve 51 and the toner ejector 5 to rotate in the opposite direction, retracting the toner ejector 5 upward to a safe position against the furnace cover 1. The spherical rotary valve 51 simultaneously closes its internal passage. The one-way toothed rod design ensures that the reset tooth is only driven during the outward pull of the accumulator piston 41, and that the reset action is not mistakenly triggered during the accumulator piston 41's forward pressure accumulation process.

[0046] At this point, all components of the device have returned to their initial state, completing a full work cycle and preparing for the next furnace or the next round of refining operations. Throughout the entire process, the shielding and protection of the graphite electrodes, the metering of carbon powder intake, high-pressure injection, and automatic reset are all automatically completed by the lifting movement of the electrode lifting column 2 through pure mechanical linkage, without the need for additional independent electrical or hydraulic drive systems.

[0047] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0048] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An LF furnace with both deep desulfurization and high-efficiency carbon enrichment functions, comprising a furnace cover (1), an electrode lifting column (2), and a graphite electrode (21), wherein the electrode lifting column (2) passes through the furnace cover (1) and the graphite electrode (21) is fixed at its bottom end, characterized in that: It also includes a retractable shielding sleeve (3), a rotating tooth (31), a first connecting rod (311), a toothed rod (32), and a pressure accumulator (4); the retractable shielding sleeve (3) is fixed at the electrode through hole at the bottom of the furnace cover (1) and sleeved around the graphite electrode (21); the rotating tooth (31) is movably sleeved on the upper end of the electrode lifting column (2), and the outer surface of the electrode lifting column (2) and the inner side of the rotating tooth (31) are provided with matching threads, so that the rotating tooth (31) is driven to rotate when the electrode lifting column (2) is raised and lowered; the upper end of the first connecting rod (311) and the... The rotating tooth (31) is fixedly connected, and its lower end is fixedly connected to the top of the movable inner layer of the retractable shielding sleeve (3) so as to drive the retractable shielding sleeve (3) to extend and retract; the toothed rod (32) meshes with the outer teeth of the rotating tooth (31) and is driven to move horizontally when the rotating tooth (31) rotates; the pressure accumulator (4) is fixed to the top of the furnace cover (1), and a pressure accumulator piston (41) is movably arranged inside it. The pressure accumulator piston (41) is fixedly connected to one end of the toothed rod (32); the outside of the pressure accumulator (4) is connected to the air inlet pipe (42), and a one-way valve is provided at the air inlet pipe (42); It also includes a carbon powder ejector (5), a quick-release disc spring (521), and a trigger pin (522). The carbon powder ejector (5) is rotatably mounted at the nozzle through hole of the furnace cover (1) via a spherical rotary valve (51) and a spring seat rod (53). The internal channel of the spherical rotary valve (51) connects the pressure accumulator (4) and the carbon powder ejector (5), and a one-way valve is provided in the channel. The quick-release disc spring (521) is mounted at the spring seat rod (53), and one end acts on the spherical rotary valve (51) to make it swing downward. The trend; the trigger pin (522) is set on the outer wall of the spherical rotary valve (51). In the non-working state, the trigger pin (522) is stuck at the limit position of the inner wall of the accumulator (4), so that the quick release disc spring (521) keeps storing energy and the spherical rotary valve (51) is closed; when the accumulator piston (41) moves towards the trigger pin (522) under the push of the rack (32), it can touch the trigger pin (522) to release the limit, so that the quick release disc spring (521) drives the spherical rotary valve (51) to swing open, and the carbon powder ejector (5) is ejected.

2. The LF furnace with both deep desulfurization and high-efficiency carbon enrichment functions according to claim 1, characterized in that: The retractable shielding sleeve (3) is composed of at least two nested heat-resistant thin-walled round tubes. The outermost sleeve is fixed at the electrode passage hole of the furnace cover (1). The inner sleeves are connected by a threaded spiral groove. The lower end of the first connecting rod (311) is fixedly connected to the top end of the innermost movable sleeve. When the first connecting rod (311) rotates, it drives the inner sleeve to rotate and extend.

3. The LF furnace with both deep desulfurization and high-efficiency carbon enrichment functions according to claim 1, characterized in that: The first link (311) is an adjustable link.

4. The LF furnace with both deep desulfurization and high-efficiency carbon enrichment functions according to claim 1, characterized in that: It also includes a linkage housing (33), which covers the outside of the rotating teeth (31) and the toothed rod (32) and is fixed to the top of the furnace cover (1).

5. An LF furnace with both deep desulfurization and high-efficiency carbon enrichment functions according to claim 1, characterized in that: The accumulator piston (41) is fixedly connected to one end of the rack (32) via an adjustable length connecting rod.

6. An LF furnace with both deep desulfurization and high-efficiency carbon enrichment functions according to claim 1, characterized in that: The one-way valve at the connection between the air inlet pipe (42) and the accumulator (4) allows gas and carbon powder to enter the accumulator (4) unidirectionally from the air inlet pipe (42).

7. An LF furnace with both deep desulfurization and high-efficiency carbon enrichment functions according to claim 1, characterized in that: The front outlet of the carbon powder ejector tube (5) is a converging nozzle.

8. An LF furnace with both deep desulfurization and high-efficiency carbon enrichment functions according to claim 1, characterized in that: The one-way valve in the internal channel of the spherical rotary valve (51) allows fluid to flow unidirectionally from the accumulator (4) to the carbon powder ejector (5).

9. An LF furnace with both deep desulfurization and high-efficiency carbon enrichment functions according to claim 1, characterized in that: It also includes a reset mechanism, which includes a reset tooth on the spring seat rod (53) and a one-way tooth on the toothed rod (32). When the toothed rod (32) pulls the accumulator piston (41) outward, the one-way tooth meshes with the reset tooth to drive the ball rotary valve (51) and the carbon powder ejector (5) to reset.

10. An LF furnace with both deep desulfurization and high-efficiency carbon enrichment functions according to claim 1, characterized in that: The retractable shielding sleeve (3) is made of silicon nitride bonded to silicon carbide.

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