Ladle filler sand removing and recycling method and device

Abstract

The invention relates to the technical field of ferrous metallurgy casting, in particular to a drainage sand removing and recycling method and device. Comprising a mechanical arm, a lifting rotation controller, a controller arm, a sand suction cylinder, a sand conveying pipeline, a sand collecting tank and an injection pump. The lifting and rotating controller is fixedly mounted on the mechanical arm; the controller arm is connected with the lifting and rotating controller, and the lifting and rotating of the controller arm are controlled by the lifting and rotating controller; the sand suction cylinder is connected with the controller arm, the sand suction cylinder is of a U-shaped structure, and one end of the sand suction cylinder is a horn mouth used for sucking drainage sand; one end of the sand conveying pipeline is positioned above the tundish cover sprue gate, and the end part of the sand conveying pipeline is bent downwards to be connected with the other end of the sand suction cylinder; the other end of the sand conveying pipeline is connected with the sand collecting tank; the sand collecting tank is connected with an injection pump pipeline, and the injection pump provides suction power. The ladle filler sand, harmful gas in gaps of the ladle filler sand and a long nozzle and a small part of molten steel in contact with the ladle filler sand in a steel ladle can be discharged out of tundish molten steel and recycled.

Description

Technical Field

[0001] This invention relates to the field of iron and steel metallurgy and casting technology, specifically to a method and apparatus for diverting and recovering sand. Background Technology

[0002] In continuous steel casting processes, multiple ladles are used for pouring. When the slide gate mechanism at the bottom of the ladle opens to begin pouring, the guide sand filling the nozzle flows out first under the static pressure of the molten steel, followed by the smooth pouring of the molten steel. During this process, the guide sand and some of the molten steel in contact with the guide sand fall together into the tundish.

[0003] The main components of the guide sand are refractory particles (such as zirconium oxide and quartz sand), which are very fine, some even reaching the micron level. These refractory particles, once inside the molten steel in the tundish, become foreign inclusions, severely contaminating the steel and affecting the purity and quality of the final product. Even more seriously, before casting, the voids in the guide sand and the inside of the long nozzle are filled with air, containing oxygen and nitrogen. When the guide sand falls into the molten steel, these gases enter with it, causing secondary oxidation and nitrogen enrichment, further deteriorating the steel quality. Furthermore, a small portion of the molten steel (approximately 15 kg) in direct contact with the guide sand in the ladle is also contaminated by it; if this contaminates the main molten steel in the tundish, it will also cause contamination.

[0004] Therefore, effectively removing and recovering the initial outflowing diversion sand and the contaminants it carries (including contaminated molten steel and air) before they enter the main molten steel in the tundish is a key technical step to significantly improve the purity of molten steel and produce high-quality steel grades.

[0005] Those skilled in the art have made numerous attempts to solve this problem, but all have failed to obtain an effective and reliable industrial solution due to the stringent limitations of the inter-laminar casting operation in the continuous casting process. These limitations mainly include: 1. Extremely short time: The time interval from closing the slide after releasing the initial diversion sand to opening the slide again to start normal pouring is very short, usually requiring all operations to be completed within 7 seconds, leaving an extremely limited effective time window for diversion sand treatment.

[0006] 2. Limited space: The maximum distance between the lower end of the long nozzle and the surface of the molten steel in the tundish is only about 300mm, leaving very little space for the equipment to enter and perform operations.

[0007] 3. Location restrictions: The end of the long nozzle is located below the tundish cover, in a relatively enclosed space, which greatly restricts the layout, movement and operation of the equipment.

[0008] Due to the aforementioned stringent working conditions, there is currently a lack of a method and device that can quickly, accurately, and automatically complete the sand removal operation in this confined space and adapt to the fast-paced continuous casting production. Summary of the Invention

[0009] To overcome the shortcomings of existing technologies, this invention provides a method and apparatus for removing and recovering diverting sand. It is capable of removing and recovering harmful gases from the diverting sand, the voids within the diverting sand, and the long nozzle, as well as a small portion of molten steel in contact with the diverting sand within the ladle, outside the molten steel in the tundish.

[0010] To achieve the above objectives, the present invention employs the following technical solution: A sand drainage and recovery device includes a robotic arm, a lifting and rotating controller, a controller arm, a sand suction cylinder, a sand conveying pipeline, a sand collection tank, and a jet pump. The lifting and rotating controller is fixedly installed on the robotic arm. The controller arm is connected to the lifting and rotating controller and is controlled by the controller to lift and rotate. The sand suction cylinder is connected to the controller arm and has a U-shaped structure, with one end being a funnel-shaped opening for sucking up drainage sand. One end of the sand conveying pipeline is located above the pouring port of the tundish cap and bends downward to connect to the other end of the sand suction cylinder. The other end of the sand conveying pipeline is connected to the sand collection tank. The sand collection tank is connected to the jet pump pipeline, and the jet pump provides the suction power.

[0011] Furthermore, the lifting and rotating controller is fixedly installed on the horizontal arm of the robotic arm.

[0012] Furthermore, the diameter of the flared end of the sand suction cylinder ranges from 120 to 300 mm.

[0013] Furthermore, the diameter of the suction cylinder is in the range of 50~120mm.

[0014] Furthermore, the sand conveying pipeline is a steel pipe with an inner diameter ranging from 50 to 120 mm.

[0015] Furthermore, one end of the sand conveying pipeline is connected to the other end via a rotary joint.

[0016] Furthermore, the sand suction cylinder is connected to the controller arm by bolts.

[0017] A method for removing and recovering diverted sand includes the following steps: S1: Install the robotic arm at the intermediate package and fix the lifting and rotation controller on the robotic arm; S2: Lay a sand conveying pipeline, connect the other end of the pipeline to the sand collection tank, extend one end of the pipeline to the top of the intermediate ladle cap pouring port, and connect one end of the pipeline to the other end of the pipeline through a rotary joint. S3: Connect the sand suction cylinder to the lifting and rotating controller via the controller arm, and connect the sand suction cylinder to one end of the sand conveying pipeline; S4: Before casting begins, the height of the ladle is lowered by using the continuous casting ladle turret, so that the lower end face of the long nozzle is within 10~300mm below the lower surface of the tundish cover, and argon gas is blown into the tundish to form a protective atmosphere. S5: Operate the robotic arm and lifting and rotating controller to move the flared mouth of the sand suction cylinder to a distance of 30~120mm directly below the long water inlet (7), and keep the sand suction cylinder above the protective slag surface; S6: Turn on the jet pump to put the sand suction cylinder nozzle in a negative pressure and suction state; S7: Open the ladle slide plate to release the diversion sand and molten steel, so that the diversion sand is sucked into the sand suction cylinder and transported to the sand collection tank through the sand conveying pipeline; S8: Based on the time required for the draining of sand from the ladle, the lifting and rotating controller is started to rotate through the control system, driving the controller arm and the sand suction cylinder to rotate to the position away from the ladle injection. S9: Repeat steps S4 to S8 before changing the ladle in continuous casting or before starting the next ladle pouring. S10: When continuous casting ends, control the robotic arm to rise up and move out of the tundish area; S11: Collect the diverted sand in the sand collection tank for reuse.

[0018] Furthermore, in S8, the time required for the sand to be drained is set by a timer. After the timer reaches the set time, the lifting and rotating controller is automatically controlled to start rotating, driving the controller arm and the sand suction cylinder to rotate to the position away from the ladle injection.

[0019] Compared with existing methods, the beneficial effects of the present invention are: 1. Significantly improves the purity of molten steel: The negative pressure suction system formed by the sand suction cylinder and the jet pump can effectively remove harmful gases such as oxygen and nitrogen entrained in the sand and its gaps from the molten steel in the tundish, avoiding these gases from entering the molten steel and causing pollution, thus significantly improving the purity of the molten steel and the quality of the product.

[0020] 2. Highly efficient operation and does not interfere with normal casting time: The device has a short processing time and can quickly complete the removal and recovery of the diversion sand before the ladle starts casting, without affecting the normal continuous casting rhythm, thus improving production efficiency.

[0021] 3. Simple and safe operation: Through the cooperation of the robotic arm and the lifting and rotating controller, the position of the sand suction cylinder is precisely controlled and the operation is automated, which reduces the difficulty and risk of manual operation and improves the safety and reliability of operation.

[0022] 4. Recycling of diversion sand: The diversion sand discharged through the sand collection tank can be collected and reused, which reduces production costs and is in line with the concept of green manufacturing and resource recycling.

[0023] 5. High adaptability and large-scale industrial application: The device has a reasonable structure and scientifically designed parameters (such as the diameter of the suction cylinder bell mouth and the diameter of the pipeline), which can adapt to the needs of continuous casting production of different specifications. It has good versatility and scalability, is suitable for large-scale industrial production, and has significant economic benefits.

[0024] 6. Synergistic effect of protective atmosphere: By blowing argon into the tundish to form a protective atmosphere, which works in synergy with the removal of slurry sand, the contact between molten steel and air is further reduced, enhancing the effect of preventing secondary oxidation of molten steel.

[0025] In summary, this invention not only solves the technical problem of molten steel contamination by diversion sand, but also has the advantages of simple operation, safety and efficiency, and resource recovery, and has important application value and promotion prospects in continuous casting production. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure and working state of the present invention.

[0027] Figure 2 This is a schematic diagram of the sand-absorbing part of the present invention.

[0028] Figure 3 This is a partial structural diagram of the sand-absorbing part of the present invention.

[0029] In the diagram: 1. Ladle; 2. Intermediate ladle; 3. Intermediate ladle cover; 4. Slag protection surface; 5. Molten steel; 6. Slide plate mechanism; 7. Long nozzle; 8. Intermediate ladle platform; 9. Robotic arm; 10. Sand suction cylinder; 11. Controller arm; 12. Sand conveying pipeline; 13. Lifting and rotating controller; 14. Jet pump; 15. Sand collection tank; 16. Joint. Detailed Implementation

[0030] This invention discloses a method and apparatus for diverting and recovering sand. Those skilled in the art can refer to the content of this document and appropriately modify the process parameters to achieve the desired result. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in this invention. The methods and applications of this invention have been described through preferred embodiments, and those skilled in the art can clearly modify or appropriately change and combine the methods and applications described herein without departing from the content, spirit, and scope of this invention to realize and apply the technology of this invention.

[0031] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0032] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "connected," and "joined" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0033] like Figures 1 to 3 As shown, a sand diversion and recovery device includes a robotic arm 9, a lifting and rotating controller 13, a controller arm 11, a sand suction cylinder 10, a sand conveying pipeline 12, a sand collection tank 15, and a jet pump 14.

[0034] The lifting and rotation controller 13 is fixedly mounted on the horizontal arm of the robotic arm 9. The controller arm 11 is connected to the output end of the lifting and rotation controller 13, which can precisely control its lifting and rotation movements.

[0035] The sand suction cylinder 10 adopts a U-shaped structure design and is connected and fixed to the controller arm 11 by bolts. The top right end of the sand suction cylinder 10 is provided with a flared mouth with a diameter of 120~300mm for efficient suction and drainage of sand; the left end is connected to the right end of the sand conveying pipeline 12. The pipeline diameter of the sand suction cylinder 10 is 50~120mm and is made of high temperature resistant and wear-resistant material.

[0036] The sand conveying pipeline 12 uses a steel pipe with an inner diameter of 50~120mm. The right end of the pipeline is located above the pouring port of the intermediate ladle cover 3, and the end bends downward and connects to the left end of the sand suction cylinder 10 through the joint 16; the right end of the pipeline is connected to the sand collection tank 15. The two sections of the sand conveying pipeline 12 are connected by a swivel joint for easy adjustment of angle and position. The sand collection tank 15 is connected to the jet pump 14 through a pipeline, and the jet pump 14 provides stable suction power.

[0037] During operation, the robotic arm 9 is first installed near the intermediate ladle platform 8, and the position of the lifting and rotating controller 13 is adjusted. The sand conveying pipeline 12 is laid, with its far end (left end) connected to the sand collection tank 15 and its near end (right end) extending above the pouring port of the intermediate ladle cover 3. The sand suction cylinder 10 is threadedly connected to the controller arm 11 through the joint 16, and the left end of the sand suction cylinder 10 is connected to the near end (right end) of the sand conveying pipeline 12.

[0038] Before pouring begins in ladle 1, the height of ladle 1 is lowered using the continuous casting ladle turret, so that the lower end face of the long nozzle 7 is 10-300mm below the lower surface of the tundish cover 3. After argon gas is blown into the tundish 2 to form a protective atmosphere, the robotic arm 9 and the lifting and rotating controller 13 are manipulated to precisely position the flared end of the sand suction cylinder 10 30-120mm directly below the long nozzle 7, ensuring it is above the protective slag surface 4 and does not contact the slag liquid. After the jet pump 14 is turned on to establish negative pressure, the sliding plate mechanism 6 is opened, and the guide sand is sucked into the sand suction cylinder 10 and transported to the sand collection tank 15 via the sand conveying pipeline 12. After a suitable time is set by the timer, the lifting and rotating controller 13 automatically moves the sand suction cylinder 10 out of the ladle pouring area.

[0039] Example 1: Continuous casting of automotive steel plates, a total of 6 ladles, with a steel ladle capacity of 260 tons.

[0040] 1. Install the robotic arm 9 near the intermediate tank so that it can easily control the sand suction cylinder 10 and the controller arm 11. Fix the lifting and rotating controller 13 to the horizontal arm of the robotic arm 9.

[0041] 2. Lay the sand conveying pipeline 12, connecting its distal end to the sand collection tank 15 and its proximal end to the top of the tundish cover pouring port. The inner diameter of both the sand suction cylinder 10 and the sand conveying pipeline 12 is 80mm, and the diameter of the flared end of the sand suction cylinder is 200mm. The portion of the pipeline above the tundish cover is connected to the remaining pipelines via a swivel joint, allowing for easy relocation above the tundish cover.

[0042] 3. Use the connecting part 16 to thread the sand suction cylinder 10 to the controller arm 11, and then install it on the lifting and rotating controller 13.

[0043] 4. Connect the sand suction cylinder 10 to the near end of the sand conveying pipeline 12. By manipulating the robotic arm 9 and the lifting and rotating controller 13, the flared mouth of the sand suction cylinder 10 can be moved directly below the long water inlet 7.

[0044] 5. Before pouring the steel into the ladle during continuous casting, the ladle height is lowered using the continuous casting ladle turret so that the lower end face of the long nozzle 7 is approximately 200mm below the lower surface of the tundish cover 3. Argon gas is then blown into the tundish to create a protective atmosphere.

[0045] 6. Operate the robotic arm 9 and the lifting and rotating controller 13 to move the flared mouth of the sand suction cylinder 10 to a position about 100mm directly below the long water inlet 7, while ensuring that the sand suction cylinder 10 is positioned above the protective slag surface 4 and does not come into contact with the slag surface.

[0046] 7. Turn on the jet pump 14 to put the horn of the sand suction cylinder 10 into a negative pressure and air suction state.

[0047] 8. Open the ladle slide to release the guide sand and molten steel. The guide sand falls into the bell mouth of the sand suction cylinder 10, is drawn into the sand suction cylinder 10 by the high-speed airflow, and then enters the sand conveying pipeline 12, and finally enters the sand collection tank 15. The guide sand and the oxygen, nitrogen and other harmful gases in its gaps are all discharged from the molten steel and no longer contaminate the molten steel.

[0048] 9. Based on the time required for the draining of sand from the ladle, the timing duration of the control system is set to 1.8 seconds. After the timer reaches the set time, the lifting and rotating controller 13 is automatically started to rotate, driving the controller arm 11 and the sand suction cylinder 10 to rotate to the position away from the ladle injection.

[0049] 10. When changing ladles in continuous casting, repeat the above operation before the next ladle is opened for pouring.

[0050] 11. When continuous casting ends, control the robotic arm 9 to rise and move out of the tundish area, in preparation for the next casting cycle.

[0051] 12. Collect the diverted sand in the sand collection tank 15 for reuse.

[0052] Testing revealed that the average total oxygen content of the continuously cast billets from this casting run was 0.0013%, while the average total oxygen content of the billets cast without dewatering sand removal was 0.0016%, resulting in an 18.8% improvement in steel purity. Furthermore, nitrogen addition in the molten steel was reduced by 0.0002%.

[0053] Example 2: Continuous casting of steel for household appliances, a total of 7 ladles, with a steel ladle capacity of 180 tons.

[0054] 1. Install the robotic arm 9 near the intermediate tank so that it can easily control the sand suction cylinder 10 and the controller arm 11. Fix the lifting and rotating controller 13 to the horizontal arm of the robotic arm 9.

[0055] 2. Lay the sand conveying pipeline 12, connecting its distal end to the sand collection tank 15 and its proximal end to the top of the tundish cover pouring port. The inner diameter of both the sand suction cylinder 10 and the sand conveying pipeline 12 is 75mm, and the diameter of the flared end of the sand suction cylinder is 180mm. The portion of the pipeline above the tundish cover is connected to the remaining pipelines via a swivel joint, allowing for easy relocation above the tundish cover.

[0056] 3. Use the connecting part 16 to thread the sand suction cylinder 10 to the controller arm 11, and then install it on the lifting and rotating controller 13.

[0057] 4. Connect the sand suction cylinder 10 to the near end of the sand conveying pipeline 12. By manipulating the robotic arm 9 and the lifting and rotating controller 13, the flared mouth of the sand suction cylinder 10 can be moved directly below the long water inlet 7.

[0058] 5. Before pouring the steel into the ladle during continuous casting, the ladle height is lowered using the continuous casting ladle turret so that the lower end face of the long nozzle 7 is approximately 200mm below the lower surface of the tundish cover 3. Argon gas is then blown into the tundish to create a protective atmosphere.

[0059] 6. Operate the robotic arm 9 and the lifting and rotating controller 13 to move the flared mouth of the sand suction cylinder 10 to a position about 100mm directly below the long water inlet 7, while ensuring that the sand suction cylinder 10 is positioned above the protective slag surface 4 and does not come into contact with the slag surface.

[0060] 7. Turn on the jet pump 14 to put the horn of the sand suction cylinder 10 into a negative pressure and air suction state.

[0061] 8. Open the ladle slide to release the guide sand and molten steel. The guide sand falls into the bell mouth of the sand suction cylinder 10, is drawn into the sand suction cylinder 10 by the high-speed airflow, and then enters the sand conveying pipeline 12, and finally enters the sand collection tank 15. The guide sand and the oxygen, nitrogen and other harmful gases in its gaps are all discharged from the molten steel and no longer contaminate the molten steel.

[0062] 9. Based on the time required for the draining of sand from the ladle, the timing duration of the control system is set to 1.6 seconds. After the timer reaches the set time, the lifting and rotating controller 13 is automatically started to rotate, driving the controller arm 11 and the sand suction cylinder 10 to rotate to the position away from the ladle injection.

[0063] 10. When changing ladles in continuous casting, repeat the above operation before the next ladle is opened for pouring.

[0064] 11. When continuous casting ends, control the robotic arm 9 to rise and move out of the tundish area, in preparation for the next casting cycle.

[0065] 12. Collect the diverted sand in the sand collection tank 15 for reuse.

[0066] Testing revealed that the average total oxygen content of the continuously cast billets from this casting run was 0.0015%, while the average total oxygen content of the billets cast without dewatering sand removal was 0.0019%, resulting in a 21% improvement in steel purity. Furthermore, nitrogen addition to the molten steel was reduced by 0.0002%.

[0067] The two embodiments above demonstrate that by optimizing the design of the structure and parameters of each component, the present invention can adapt to continuous casting production with different steel grades and process requirements, effectively improve the purity of steel, and has significant technical and economic benefits.

[0068] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A device for diverting, discharging, and recovering sand, characterized in that, It includes a robotic arm (9), a lifting and rotating controller (13), a controller arm (11), a sand suction cylinder (10), a sand conveying pipeline (12), a sand collection tank (15), and a jet pump (14). The lifting and rotating controller (13) is fixedly installed on the robotic arm (9); The controller arm (11) is connected to the lifting and rotating controller (13), and its lifting and rotating are controlled by the lifting and rotating controller (13); The sand suction cylinder (10) is connected to the controller arm (11). The sand suction cylinder (10) has a U-shaped structure, with one end being a funnel-shaped opening for sucking up and draining sand. One end of the sand conveying pipeline (12) is located above the pouring port of the intermediate ladle cover, and the end is bent downwards and connected to the other end of the sand suction cylinder (10); the other end of the sand conveying pipeline (12) is connected to the sand collection tank (15); The sand collection tank (15) is connected to the jet pump (14) via pipeline, and the jet pump (14) provides the suction power.

2. The sand discharge and recovery device according to claim 1, characterized in that, The lifting and rotating controller (13) is fixedly installed on the horizontal arm of the robotic arm (9).

3. The sand discharge and recovery device according to claim 1, characterized in that, The diameter of the flared end of the sand suction cylinder (10) ranges from 120 to 300 mm.

4. The sand drainage and recovery device according to claim 3, characterized in that, The diameter of the suction cylinder (10) is in the range of 50~120mm.

5. The sand discharge and recovery device according to claim 1, characterized in that, The sand conveying pipeline (12) is a steel pipe with an inner diameter ranging from 50 to 120 mm.

6. The sand diversion and recovery device according to claim 1, characterized in that, The sand conveying pipeline (12) is connected at one end to the other end via a rotary joint.

7. The sand discharge and recovery device according to claim 1, characterized in that, The sand suction cylinder (10) is connected to the controller arm (11) by bolts.

8. A method for draining and recovering sand using the apparatus described in any one of claims 1-7, characterized in that, Includes the following steps: S1: Before the steel ladle is started to pour, the height of the steel ladle is reduced by the continuous casting steel ladle turntable so that the lower end face of the long nozzle (7) is located within 10~300mm below the lower surface of the tundish cover (3), and argon gas is blown into the tundish to form a protective atmosphere. S2: Operate the robotic arm (9) and lifting and rotating controller (13) to move the flared mouth of the sand suction cylinder (10) to a distance range of 30~120mm directly below the long water inlet (7), and keep the sand suction cylinder (10) above the protective slag surface (4); S3: Turn on the jet pump (14) to put the horn of the sand suction cylinder (10) into a negative pressure and air suction state; S4: Open the ladle slide plate to release the diversion sand and molten steel, so that the diversion sand is sucked into the sand suction cylinder (10) and transported to the sand collection tank (15) through the sand conveying pipeline (12). S5: Based on the time required for the drain sand to be completely drained from the ladle, the lifting and rotating controller (13) is started to rotate through the control system, driving the controller arm (11) and the sand suction cylinder (10) to rotate to the position away from the ladle injection. S6: Repeat steps S1 to S5 before changing the ladle in continuous casting or before starting the next ladle pouring.

9. The method for removing and recovering diverted sand according to claim 8, characterized in that, In S5, the time required for the sand to be drained is set by a timer. After the timer reaches the set time, the lifting and rotating controller (13) is automatically controlled to start rotating, which drives the controller arm (11) and the sand suction cylinder (10) to rotate to the position away from the ladle injection.

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