A molten iron filtering device for casting

Abstract

This invention discloses a molten iron filtration device for casting, belonging to the field of molten iron filtration. The device includes a filter cylinder with a filter element at its center. The filter element comprises a spherical section, a cylindrical section, a conical section, and filter holes, connected sequentially from top to bottom. A plurality of filter holes are evenly distributed circumferentially along the spherical, cylindrical, and conical sections. A spiral guide plate is fitted between the cylindrical section and the interior of the filter cylinder. The cross-sectional diameter of the conical section gradually increases from the direction away from the cylindrical section, and the bottom cross-section of the conical section is equal to the inner cross-section of the filter cylinder. A container is located below the conical section to receive the filtered molten iron. This invention, through the cooperation of the filter element composed of the spherical, cylindrical, and conical sections and the spiral guide plate, causes the molten iron to flow in a spiral pattern. Centrifugal force scours the filter holes to prevent clogging, and the conical diameter expansion provides uniform, large-area filtration, significantly improving filtration efficiency and continuity.

Description

Technical Field

[0001] This invention relates to the field of molten iron filtration technology, specifically to a molten iron filtration device for casting. Background Technology

[0002] In metal casting processes, molten iron filtration is a crucial purification step for removing inclusions and slag from molten metal, playing a decisive role in improving the internal quality of castings and reducing casting defects. Molten iron filtration devices are typically installed between the ladle and the gating system, using porous filter elements made of refractory materials to trap non-metallic particles in the molten iron, thus achieving purification.

[0003] In existing technologies, common molten iron filtration devices often employ flat-plate filter screens or simple cylindrical filter elements, allowing molten iron to pass vertically through the filter surface under gravity, while large-sized slag is intercepted upstream. For example, one design uses a straight cylindrical filter screen inside a filter cylinder, where molten iron directly impacts the screen surface for filtration. While this structure is simple, during continuous pouring, the molten iron impacts the filter surface in a direct current, making it easy for slag to accumulate and adhere at the filter hole inlet, leading to rapid clogging and a continuous reduction in the effective filtration area. Simultaneously, the uneven distribution of molten iron on the filter surface, with high local flow velocities, further exacerbates screen wear and clogging.

[0004] However, the above-mentioned molten iron filtration device still has the following defects: the filter element is easily clogged by molten slag, and the molten iron is unevenly distributed on the filter surface, resulting in low filtration efficiency. Frequent shutdowns are required to clean or replace the filter element, which seriously affects the continuity and cycle of casting production and makes it difficult to meet the needs of efficient automated casting production. Summary of the Invention

[0005] The purpose of this invention is to provide a molten iron filtration device for casting, in order to solve the problems in the prior art where the filter element is easily clogged by molten slag, the molten iron is unevenly distributed on the filter surface, resulting in low filtration efficiency, the need for frequent shutdowns for cleaning, and the inability to achieve efficient continuous casting.

[0006] The technical problem to be solved by the present invention can be achieved by the following technical solution: a molten iron filtration device for casting, comprising a filter cylinder, wherein a filter element is provided at the center of the filter cylinder, the filter element comprising a spherical part, a cylindrical part, a conical part and filter holes, the spherical part, the cylindrical part and the conical part being connected sequentially from top to bottom, and a plurality of filter holes being evenly distributed circumferentially along the spherical part, the cylindrical part and the conical part, a spiral guide plate being fitted between the cylindrical part and the interior of the filter cylinder, the cross-sectional diameter of the conical part gradually increasing from the direction away from the cylindrical part, and the bottom cross-section of the conical part being equal to the inner cross-section of the filter cylinder, and a tank for receiving the filtered molten iron being provided below the conical part.

[0007] Preferably, the top inner wall of the filter cylinder is connected to a flow guide shroud with a cross-section that gradually decreases from top to bottom, and the liquid outlet at the bottom of the flow guide shroud is located directly above the spherical surface. The bottom of the tank is connected to a sliding water outlet for controlling the discharge of molten iron.

[0008] Preferably, the filter cylinder is fitted with an annular shell with a bottom opening near the bottom end, and the filter cylinder is rotatably connected to the annular shell. A circumferentially distributed bracket is connected between the inner side wall of the annular shell and the outer side wall of the tank. A rotating mechanism for driving the filter cylinder to rotate is installed on the annular shell. The spiral guide plate is fixedly connected to the inner wall of the filter cylinder, and the spiral guide plate is movably sleeved with the filter element.

[0009] Preferably, the rotating mechanism includes an external gear ring, a gear, and a motor. The motor is mounted on the top of the annular shell, the gear is coaxially connected to the output shaft of the motor, and the external gear ring is fitted onto the outer wall of the filter cartridge, with the external gear ring meshing with the gear.

[0010] Preferably, one end of the spiral guide plate is connected to an arc-shaped scraper that conforms to the spherical surface, and the spiral guide plate drives the arc-shaped scraper to move circumferentially along the spherical surface when it rotates with the filter cylinder.

[0011] Preferably, the inner wall of the cylindrical part is equipped with a plurality of drainage rings evenly distributed from top to bottom, and the inner diameter of the drainage rings decreases sequentially from top to bottom. The plurality of drainage rings are staggered with a plurality of circumferentially distributed filter holes on the cylindrical part.

[0012] Preferably, a movable component is connected near the bottom of the conical portion, which can fit against the bottom edge of the filter cylinder, and the movable component is slidably inserted into the tank body. A negative pressure lifting mechanism is installed between the annular shell and the movable component. Under negative pressure, the negative pressure lifting mechanism is used to lift the movable component to fit tightly against the bottom edge of the filter cylinder. Under normal pressure, the negative pressure lifting mechanism is used to drive the movable component down, so that the conical portion at the bottom of the filter component is lowered below the filter cylinder, thereby automatically guiding the filter residue on the conical portion into the annular shell for discharge.

[0013] Preferably, the movable component includes a guide ring and an annular barrier. The guide ring is fixedly sleeved on the outer wall of the bottom end of the conical part. The top of the guide ring and the bottom end of the filter cylinder are both inclined structures. The annular barrier is coaxially connected to the bottom of the movable component and is slidably inserted into the tank body.

[0014] Preferably, the negative pressure lifting mechanism includes a cylinder, a piston, an L-shaped rod, a spring, an arc-shaped tube, and an air extraction pipe with an air inlet valve. Multiple cylinders are circumferentially fixed to the top of an annular shell, and the cylinders are in communication with the interior of the annular shell. The piston is slidably disposed within the cylinder. The spring is installed between the piston and the inner end of the cylinder. One end of the L-shaped rod is connected to the bottom of the piston, and the other end of the L-shaped rod extends to the outside of the cylinder and connects to the outer wall of the movable part. The arc-shaped tube is connected between the cylinder walls of two adjacent cylinders near their top ends. The air extraction pipe is in communication with one of the cylinders near its top end, and the air inlet valve is installed on the air extraction pipe.

[0015] Preferably, the outer wall of the tank is fixedly fitted with an annular material trough located directly below the annular shell, and the bottom of the annular material trough is connected to an arc-shaped discharge port.

[0016] Compared with the prior art, the beneficial effects of this application are as follows: 1. This invention utilizes a three-dimensional filter element consisting of a spherical section, a cylindrical section, and a conical section connected in sequence. Combined with a spiral guide plate fitted inside the cylindrical section of the filter cylinder, molten iron is initially dispersed along the spherical section before entering the cylindrical section. Molten iron that fails to pass through the filter holes in the cylindrical section flows downwards along the spiral guide plate. During this flow, the circumferentially distributed filter holes in the cylindrical section provide thorough filtration, extending the contact path and time between the molten iron and the filter element, significantly improving filtration efficiency. Simultaneously, the centrifugal force generated by the spiral flow helps to flush and separate filter residue from the filter hole surface, reducing clogging and ensuring continuous smooth filtration. The gradually increasing diameter of the conical section allows for further filtration of unfiltered molten iron. The bottom section being equal to the cross-section inside the filter cylinder ensures that all molten iron is filtered before entering the tank, achieving efficient and thorough filtration of the molten iron.

[0017] 2. This invention utilizes a three-section three-dimensional filtration structure consisting of a spherical section, a cylindrical section, and a conical section. Combined with a spiral guide plate, this structure allows molten iron to flow in an orderly spiral pattern on the outside of the filter element. Centrifugal force is used to trap slag on the outer wall of the filter element and push it downstream with the flowing molten iron. Simultaneously, clean molten iron passes through the filter holes from the outside to the inside of the filter element. This transforms the traditional passive interception filtration into a combination of active centrifugal separation and dynamic slag discharge. The conical expansion section provides a large-area uniform filtration channel, thereby effectively solving the problems of filter hole clogging and uneven filtration. Attached Figure Description

[0018] Figure 1 This is a perspective view of a molten iron filtration device for casting according to the present invention; Figure 2 This is a cross-sectional view of a molten iron filtration device for casting according to the present invention during filtration. Figure 3This is a cross-sectional view of the slag discharge process of a molten iron filtration device for casting according to the present invention; Figure 4 This is a cross-sectional view of the connection between the moving part and the filter element in a molten iron filtration device for casting according to the present invention. Figure 5 This is a perspective view of the connection between the spiral guide plate and the filter element in a molten iron filtration device for casting according to the present invention. Figure 6 This is a perspective view of the rotating mechanism in a molten iron filtration device for casting according to the present invention; Figure 7 This is a perspective view of the connection between the movable part and the negative pressure lifting mechanism in a molten iron filtration device for casting according to the present invention. Figure 8 This is a partial cross-sectional view of the negative pressure lifting mechanism in a molten iron filtration device for casting according to the present invention.

[0019] Explanation of reference numerals in the attached figures: 100. Filter cartridge; 101. Spiral guide plate; 102. Arc-shaped scraper; 103. Flow guide hood; 200. Filter element; 201. Spherical part; 202. Cylindrical part; 203. Conical part; 204. Filter hole; 205. Flow guide ring; 300. Tank body; 301. Sliding nozzle; 302. Annular material trough; 303. Arc-shaped discharge port; 400. Annular shell; 401. Support; 500. Rotating mechanism; 501. External gear ring; 502. Gear; 503. Motor; 600. Moving part; 601. Guide ring; 602. Annular enclosure; 700. Negative pressure lifting mechanism; 701. Cylinder body; 702. Piston; 703. L-shaped rod; 704. Spring; 705. Arc-shaped tube; 706. Air inlet valve; 707. Air extraction pipe. Detailed Implementation

[0020] The specific embodiments of the present invention will be described in detail below, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0021] Example 1 In existing molten iron filtration devices, the filter elements are mostly flat plate filter screens or straight cylindrical structures. Molten iron impacts the filter surface vertically under the action of gravity, and slag directly accumulates at the inlet of the filter holes. Moreover, the molten iron is unevenly distributed on the filter surface, and the local flow velocity is high, which makes the filter holes very easy to be blocked by slag. The filtration efficiency is low, and frequent shutdowns are required to clean or replace the filter elements, which seriously affects the continuity and cycle of casting production.

[0022] like Figures 1 to 4In this embodiment, a molten iron filtration device for casting is provided, including a filter cylinder 100. A filter element 200 is provided at the center of the filter cylinder 100. The filter element 200 includes a spherical part 201, a cylindrical part 202, a conical part 203, and filter holes 204. The spherical part 201, the cylindrical part 202, and the conical part 203 are connected sequentially from top to bottom. A plurality of filter holes 204 are evenly distributed circumferentially along the spherical part 201, the cylindrical part 202, and the conical part 203. A spiral guide plate 101 is fitted between the cylindrical part 202 and the interior of the filter cylinder 100. The cross-sectional diameter of the conical part 203 gradually increases from the direction away from the cylindrical part 202, and the bottom cross-section of the conical part 203 is equal to the inner cross-section of the filter cylinder 100. A tank 300 for receiving the filtered molten iron is provided below the conical part 203.

[0023] The working principle of this embodiment is as follows: Figure 2 and Figure 4 During casting, molten iron is poured in from above, first landing on the spherical surface 201. The spherical structure evenly disperses the molten iron in all directions. Molten iron that directly passes through the filter holes 204 on the spherical surface 201 enters the interior of the filter element 200 and falls into it. Molten iron dispersed along the surface of the spherical surface 201 to the edges enters the annular space between the outer wall of the filter element 200 and the inner wall of the filter cylinder 100. Under the forced guidance of the spiral guide plate 101, it flows spirally downwards along the outer wall of the cylindrical portion 202. Clean molten iron radially inwards passes through the filter holes 204 on the cylindrical portion 202 into the interior of the filter element 200 and falls. The centrifugal force generated by the spiral flow continuously acts on the surface area of ​​the filter holes 204, washing away the filter residue attached to or near the filter holes 204, effectively reducing the clogging of the filter holes 204. The washed-away filter residue is continuously carried downwards by the spirally flowing molten iron and gradually pushed to the lower conical portion 203 area. The diameter of the conical part 203 gradually increases from top to bottom, providing ample filtration area for the molten iron. The molten iron continues to pass through the filter holes 204 into the interior of the filter element 200, and finally collects and falls into the tank 300. The intercepted filter residue accumulates on the outer surface of the conical part 203 under the influence of the molten iron flow, thus completing the separation of molten iron and filter residue.

[0024] It should be emphasized that the core improvement of this embodiment lies in the following: the three-section three-dimensional filter structure composed of the spherical part 201, the cylindrical part 202, and the conical part 203, combined with the spiral guide plate 101, makes the molten iron form an orderly spiral flow on the outside of the filter element 200. The centrifugal force is used to trap the slag on the outer wall of the filter element 200 and push it downstream with the flowing molten iron. At the same time, the clean molten iron passes through the filter hole 204 from the outside to the inside and enters the interior of the filter element 200. The traditional passive interception filtration is transformed into a combination of active centrifugal separation and dynamic slag discharge. The conical expansion section provides a large area of ​​uniform filtration channel, thereby effectively solving the problems of filter hole blockage and uneven filtration.

[0025] like Figure 2 In this embodiment, a flow guide shroud 103 with a gradually decreasing cross-section is connected to the inner wall of the top of the filter cylinder 100. The bottom outlet of the flow guide shroud 103 is located directly above the spherical surface 201. The flow guide shroud 103 can accurately collect the falling molten iron at the top center of the spherical surface 201, preventing molten iron from splashing and forming a uniform initial distribution. This allows the molten iron to enter the spherical surface 201 at an ideal angle and speed for diversion, ensuring that some molten iron directly passes through the spherical surface 201 into the filter element 200, while the remaining molten iron uniformly enters the annular space to participate in spiral filtration. The bottom of the tank 300 is connected to a sliding gate 301 for controlling the discharge of molten iron, which facilitates precise control of the pouring flow rate and meets the differentiated requirements of different castings for pouring speed.

[0026] like Figure 4 In this embodiment, a plurality of flow-guiding rings 205 are evenly distributed from top to bottom on the inner wall of the cylindrical portion 202, and the inner diameter of the flow-guiding rings 205 decreases sequentially from top to bottom. The plurality of flow-guiding rings 205 are staggered with a plurality of circumferentially distributed filter holes 204 on the cylindrical portion 202. The design motivation of the flow-guiding rings 205 is that when clean molten iron enters the filter element 200 through the filter holes 204 of the cylindrical portion 202, some of the molten iron falls along the inner wall of the filter element 200. The flow-guiding rings 205 can intercept this part of the molten iron and guide it towards the central area of ​​the filter element 200, so that the molten iron entering the filter element 200 is evenly gathered and falls, avoiding the molten iron from "short-circuiting" and falling straight down along the inner wall, which would cause the local flow velocity to be too high. This ensures the stability of the molten iron flow inside the filter element 200, and also helps to balance the pressure inside and outside the filter element 200, further improving the filtration efficiency.

[0027] Example 2 It is understandable that in Embodiment 1, although the spiral guide plate 101 is used to achieve the spiral flow of molten iron on the outside of the cylindrical part 202, and the filter slag is washed away and pushed downward by centrifugal force, during the long-term continuous casting process, some molten slag with strong adhesion may still gradually adhere to the periphery of the filter holes 204 on the outer wall of the cylindrical part 202, thereby weakening the local filtration capacity.

[0028] like Figure 2 To solve the above problems, in this embodiment, an annular shell 400 with a bottom opening is fitted near the bottom of the filter cylinder 100, and the filter cylinder 100 is rotatably connected to the annular shell 400. A circumferentially distributed bracket 401 is connected between the inner side wall of the annular shell 400 and the outer side wall of the tank 300. A rotating mechanism 500 for driving the filter cylinder 100 to rotate is installed on the annular shell 400. The spiral guide plate 101 is fixedly connected to the inner wall of the filter cylinder 100, and the spiral guide plate 101 is movably sleeved with the filter element 200.

[0029] The working principle of this embodiment is as follows: Figure 2 and Figure 5 When the rotating mechanism 500 drives the filter cylinder 100 to rotate, the spiral guide plate 101 fixed to the inner wall of the filter cylinder 100 rotates synchronously, while the filter element 200 remains stationary because its lower end is fixed relative to the tank body 300. At this time, the spiral guide plate 101 rotates relative to the outer wall of the filter element 200, and its spiral surface forms a continuous mechanical scraping action, which can forcibly peel off the slag attached to the outer wall of the cylindrical part 202; at the same time, the rotating spiral guide plate 101 also applies a stronger rotational driving force to the molten iron in the annular space, which enhances the spiral flow speed and centrifugal force of the molten iron, so that the peeled filter slag is more effectively transported to the downstream conical part 203 area with the molten iron, thereby keeping the filter holes 204 unobstructed and realizing the simultaneous operation of filtration and dynamic self-cleaning.

[0030] It should be emphasized that the core improvement of this embodiment lies in: by giving the filter cylinder 100 and the spiral guide plate 101 a degree of rotational freedom, and by making the spiral guide plate 101 and the stationary filter element 200 form a controllable relative motion, the original static spiral guide structure is upgraded into a mechanism with both guiding and rotating slag scraping functions. This actively and continuously removes the slag attached to the outer wall of the filter element 200, overcoming the defect of slow slag accumulation in static cyclone filtration, while enhancing the cyclone intensity of molten iron, and further improving the centrifugal scouring effect and filtration efficiency.

[0031] like Figure 1 and Figure 6 In this embodiment, the rotating mechanism 500 includes an external gear ring 501, a gear 502, and a motor 503. The motor 503 is mounted on the top of the annular shell 400. The gear 502 is coaxially connected to the output shaft of the motor 503. The external gear ring 501 is fitted onto the outer wall of the filter cylinder 100, and the external gear ring 501 meshes with the gear 502. The motor 503 drives the gear 502 to rotate, which in turn drives the filter cylinder 100 to rotate smoothly through the external gear ring 501. The structure is compact, the transmission is reliable, and the speed can be flexibly adjusted according to the casting conditions.

[0032] like Figure 2 and Figure 5In this embodiment, an arc-shaped scraper 102 that conforms to the spherical surface 201 is connected to one end of the spiral guide plate 101. When the spiral guide plate 101 rotates with the filter cylinder 100, it drives the arc-shaped scraper 102 to move circumferentially along the spherical surface 201. Since the spherical surface 201 is the area where molten iron first comes into contact, slag is most likely to initially adhere and accumulate here. The arc-shaped scraper 102 is specifically designed to scrape off any slag that may accumulate in the spherical area, preventing slag formation from affecting the initial diversion effect of the molten iron. The spiral guide plate 101 and the filter element 200 are movably sleeved together, with a small gap between them. This ensures smooth relative rotation while maintaining good flow guidance and slag scraping effects. Moreover, this gap is much smaller than the aperture of the filter hole 204, preventing unfiltered molten iron from short-circuiting into the gap.

[0033] Example 3 Understandably, in Embodiment 2, the rotating spiral guide plate 101 enables online slag removal from the outer wall of the filter element 200. However, the scraped-off slag will eventually accumulate on the outer surface of the conical portion 203 and in the area where the bottom of the conical portion 203 meets the bottom edge of the filter cylinder 100. If not discharged in time, this accumulated slag may clog the filter holes 204 on the conical portion 203 or be re-rolled into the molten iron. Manual or machine shutdown slag removal will reduce production efficiency.

[0034] like Figures 2 to 3 To address the aforementioned issues, in this embodiment, a movable component 600 is connected near the bottom of the conical portion 203, which can fit against the bottom edge of the filter cylinder 100. The movable component 600 is slidably inserted into the tank body 300. A negative pressure lifting mechanism 700 is installed between the annular shell 400 and the movable component 600. Under negative pressure, the negative pressure lifting mechanism 700 is used to lift the movable component 600 to fit tightly against the bottom edge of the filter cylinder 100. Under normal pressure, the negative pressure lifting mechanism 700 is used to drive the movable component 600 down, causing the conical portion 203 at the bottom of the filter element 200 to descend below the filter cylinder 100, thereby automatically guiding the filter residue on the conical portion 203 into the annular shell 400 for discharge.

[0035] The working principle of this embodiment is as follows: Figures 2 to 4During normal filtration, a negative pressure is generated inside the negative pressure lifting mechanism 700 by the air extraction device. This drives the movable part 600 to rise and press against the bottom edge of the filter cylinder 100, forming a seal. This ensures that all the molten iron in the annular space passes through the filter holes 204 into the filter element 200 under pressure and flows into the tank 300, preventing leakage from the bottom. When slag discharge is required, the air extraction is turned off and air is introduced. The negative pressure lifting mechanism 700 returns to normal pressure, and the movable part 600 moves downward under the action of the internal elastic element, causing the entire filter element 200 to descend. The conical part 203 then moves down to below the filter cylinder 100. At this time, the filter slag accumulated on the outer surface of the conical part 203 automatically slides into the annular shell 400 under the action of gravity and the inclination of the conical surface, thus achieving automatic slag discharge without stopping the machine or disassembling it. After slag discharge is completed, the air extraction is restarted to establish negative pressure, and the movable part 600 rises again to press against the filter cylinder 100, restoring normal filtration.

[0036] It should be emphasized that the core improvement of this embodiment is that a liftable movable part 600 and a negative pressure lifting mechanism 700 are introduced at the bottom of the filter element 200. The switching between negative pressure and normal pressure controls the sealing filtration state and the descent slag discharge state of the filter element 200, so that the filter slag on the outer surface of the conical part 203 can be automatically discharged into the annular shell 400 by its own inclination. This solves the problem that the filter slag is difficult to be automatically discharged after the rotating scraper collects, ensuring continuous and automated operation of the whole process, and enabling the device to adapt to the needs of long-term uninterrupted casting production.

[0037] like Figures 3 to 4 In this embodiment, the movable component 600 includes a guide ring 601 and an annular baffle 602. The guide ring 601 is fixedly sleeved on the outer wall of the bottom end of the conical part 203. The top of the guide ring 601 and the bottom end of the filter cylinder 100 are both inclined structures. When the movable component 600 descends, the inclined surface forms a smooth guide slope, ensuring that the filter residue sliding off the outer surface of the conical part 203 enters the annular shell 400 without residue. The annular baffle 602 is coaxially connected to the bottom of the movable component 600, and the annular baffle 602 is slidably inserted into the tank body 300, forming a shield on the upper opening of the tank body 300 to prevent molten iron from splashing or filter residue from falling into the tank body 300 during the slag discharge process, while ensuring that the filtered clean molten iron can still flow smoothly into the tank body 300.

[0038] like Figures 7 to 8In this embodiment, the negative pressure lifting mechanism 700 includes a cylinder 701, a piston 702, an L-shaped rod 703, a spring 704, an arc-shaped tube 705, and an air extraction pipe 707 with an air inlet valve 706. Multiple cylinders 701 are circumferentially fixed on the top of the annular shell 400, and the cylinders 701 are in communication with the interior of the annular shell 400. The piston 702 is slidably disposed inside the cylinder 701. The spring 704 is installed between the piston 702 and the inner end of the cylinder 701, and is used to push the piston 702 to reset after the negative pressure is released. One end of the L-shaped rod 703 is connected to the bottom of the piston 702, and the other end of the L-shaped rod 703 extends to the outside of the cylinder 701 and connects to the outer wall of the movable member 600, converting the linear motion of the piston 702 into the lifting action of the movable member 600. When the air inlet valve 706 is opened to restore normal pressure inside the cylinder 701, the elastic potential energy stored in the spring 704 is rapidly released, pushing the piston 702 to accelerate downwards. This, in turn, drives the moving part 600 to accelerate downwards via the L-shaped rod 703. During this process, the L-shaped rod 703 descends rapidly with the moving part 600 and collides with the top edge of the tank 300, causing the moving part 600 and the filter element 200 connected to it to vibrate. This effectively shakes off the filter residue adhering to the outer surface of the conical part 203 and near the filter holes 204. Combined with the inclined guiding effect of the conical surface, the filter residue is discharged more thoroughly into the annular shell 400. The arc-shaped pipe 705 is connected between the walls of two adjacent cylinders 701 near the top to achieve balanced air pressure in each cylinder 701, ensuring synchronous lifting and lowering of the moving parts 600 around the circumference and avoiding skewness and jamming. The exhaust pipe 707 is connected to one of the cylinders 701 near the top, and the air inlet valve 706 is installed on the exhaust pipe 707. By controlling the opening and closing of the air inlet valve 706, the negative pressure and normal pressure states can be easily switched. The operation is simple and the response is rapid.

[0039] like Figures 1 to 2 In this embodiment, an annular material trough 302 located directly below the annular shell 400 is fixedly sleeved on the outer wall of the tank body 300. An arc-shaped discharge port 303 is installed at the bottom of the annular material trough 302. The filter residue sliding down from the conical part 203 passes through the annular shell 400 and falls into the annular material trough 302, and is discharged in a concentrated manner through the arc-shaped discharge port 303, which facilitates unified collection and treatment and prevents the filter residue from accumulating in large quantities in the annular shell 400 and affecting the normal operation of the slag discharge mechanism.

[0040] The basic principles, main features, and advantages of this application have been described above. Those skilled in the art should understand that this application is not limited to the above embodiments. The embodiments and descriptions in the specification are merely the principles of this application. Various changes and modifications can be made to this application without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed application.

Claims

1. A molten iron filtration device for casting, comprising a filter cylinder (100), characterized in that, The filter cylinder (100) has a filter element (200) at its center. The filter element (200) includes a spherical part (201), a cylindrical part (202), a conical part (203), and filter holes (204). The spherical part (201), the cylindrical part (202), and the conical part (203) are connected sequentially from top to bottom. A number of filter holes (204) are evenly distributed around the spherical part (201), the cylindrical part (202), and the conical part (203). A spiral guide plate (101) is fitted between the cylindrical part (202) and the inside of the filter cylinder (100). The cross-sectional diameter of the conical part (203) gradually increases from the direction away from the cylindrical part (202), and the bottom cross-section of the conical part (203) is equal to the inner cross-section of the filter cylinder (100). A tank (300) for receiving the filtered molten iron is provided below the conical part (203).

2. The molten iron filtering device for casting as described in claim 1, characterized in that, The filter cylinder (100) has a flow guide shroud (103) with a cross-section that gradually decreases from top to bottom connected to the inner wall of the top. The liquid outlet of the flow guide shroud (103) is located directly above the spherical surface (201). The bottom of the tank (300) is connected to a sliding water outlet (301) for controlling the discharge of molten iron.

3. The molten iron filtering device for casting as described in claim 1, characterized in that, The filter cylinder (100) is fitted with an annular shell (400) with a bottom opening near the bottom end, and the filter cylinder (100) is rotatably connected to the annular shell (400). A circumferentially distributed bracket (401) is connected between the inner side wall of the annular shell (400) and the outer side wall of the tank (300). A rotating mechanism (500) for driving the filter cylinder (100) to rotate is installed on the annular shell (400). The spiral guide plate (101) is fixedly connected to the inner wall of the filter cylinder (100), and the spiral guide plate (101) is movably sleeved with the filter element (200).

4. The molten iron filtering device for casting as described in claim 3, characterized in that, The rotating mechanism (500) includes an external gear ring (501), a gear (502) and a motor (503). The motor (503) is mounted on the top of the annular shell (400). The gear (502) is coaxially connected to the output shaft of the motor (503). The external gear ring (501) is fitted onto the outer wall of the filter cartridge (100), and the external gear ring (501) and the gear (502) are meshed.

5. The molten iron filtering device for casting as described in claim 3, characterized in that, The spiral guide plate (101) has an arc-shaped scraper (102) attached to one side of the end of the spiral guide plate (101) and the arc-shaped scraper (102) moves circumferentially along the spherical surface (201) when the spiral guide plate (101) rotates with the filter cylinder (100).

6. The molten iron filtering device for casting as described in claim 1, characterized in that, The inner wall of the cylindrical part (202) is equipped with a plurality of drainage rings (205) evenly distributed from top to bottom, and the inner diameter of the drainage rings (205) decreases from top to bottom. The plurality of drainage rings (205) are staggered with a plurality of circumferentially distributed filter holes (204) on the cylindrical part (202).

7. The molten iron filtering device for casting as described in claim 3, characterized in that, The conical part (203) is connected to a movable part (600) near the bottom end, which can fit against the bottom edge of the filter cylinder (100). The movable part (600) is slidably inserted into the tank body (300). A negative pressure lifting mechanism (700) is installed between the annular shell (400) and the movable part (600). The negative pressure lifting mechanism (700) is used to lift the movable part (600) and the bottom edge of the filter cylinder (100) to fit tightly under negative pressure. Under normal pressure, the negative pressure lifting mechanism (700) is used to drive the movable part (600) to descend, so that the conical part (203) at the bottom end of the filter element (200) descends to below the filter cylinder (100), thereby automatically guiding the filter residue on the conical part (203) into the annular shell (400) for discharge.

8. The molten iron filtering device for casting as described in claim 7, characterized in that, The movable part (600) includes a guide ring (601) and an annular barrier (602). The guide ring (601) is fixedly sleeved on the outer wall of the bottom end of the conical part (203). The top of the guide ring (601) and the bottom end of the filter cylinder (100) are both inclined structures. The annular barrier (602) is coaxially connected to the bottom of the movable part (600) and is slidably inserted into the tank body (300).

9. A molten iron filtering device for casting as described in claim 7, characterized in that, The negative pressure lifting mechanism (700) includes a cylinder (701), a piston (702), an L-shaped rod (703), a spring (704), an arc-shaped tube (705), and an air extraction pipe (707) with an air inlet valve (706). Multiple cylinders (701) are circumferentially fixed on the top of the annular shell (400), and the cylinders (701) are internally connected to the annular shell (400). The piston (702) is slidably disposed within the cylinder (701), and the spring (704) is installed between the piston (702) and the annular shell (400). Between the inner ends of the cylinder (701), one end of the L-shaped rod (703) is connected to the bottom of the piston (702), and the other end of the L-shaped rod (703) extends to the outside of the cylinder (701) and is connected to the outer wall of the movable part (600). The arc-shaped tube (705) is connected between the cylinder walls of two adjacent cylinders (701) near the top. The exhaust pipe (707) is connected to one of the cylinders (701) near the top. The air inlet valve (706) is installed on the exhaust pipe (707).

10. A molten iron filtering device for casting as described in claim 3, characterized in that, The outer wall of the tank (300) is fixedly fitted with an annular material trough (302) located directly below the annular shell (400), and the bottom of the annular material trough (302) is connected to an arc-shaped discharge port (303).

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