Fused magnesia furnace with center feeding function

Abstract

The invention discloses a center charging fused magnesite furnace, which relates to the technical field of electric melting furnaces, and comprises a rack, a furnace seat, a crucible, a furnace cover, a graphite electrode, a conveying pipe, a communicating pipe, a connecting pipe, a gas outlet interface, a gas injection part and an inclined hole, and the graphite electrode penetrates through the gas injection part in a sliding manner; the rotating unit is arranged on the gas spraying part and used for driving the gas spraying part to rotate, and during use, inert gas is conveyed to the conveying pipe through an external inert gas conveying system, then conveyed to the connecting pipe through the communicating pipe, enters the inclined hole of the gas spraying part through the communicating cavity between the connecting pipe and the graphite electrode, and then is sprayed to the surface of slag through the hole opening of the inclined hole; and meanwhile, the rotating unit drives the air injection part to rotate, so that the inert gas generates driving force on the slag near the graphite electrode in the circumferential direction, the slag near the graphite electrode flows in the circumferential direction, large resistance is generated on the slag moving towards the graphite electrode, and chemical corrosion of the slag on the graphite electrode is reduced.

Description

Technical Field

[0001] This invention relates to the field of electric melting furnace technology, and more specifically to a center-feed electric fused magnesia furnace. Background Technology

[0002] Magnesia, also known as sintered magnesia, is produced by calcining magnesium hydroxide (obtained from magnesite, brucite, or by reacting seawater with lime slurry) at high temperatures. It has strong hydration properties. It is mainly used in the manufacture of alkaline refractory materials, such as magnesia bricks and magnesia-alumina bricks. Magnesia with high impurity content is used for lining the bottom of steelmaking furnaces. Its main chemical component is MgO, and its mineral composition is periclase, an isometric crystal system. It has a density of 3.56–3.65 g / cm³, a Mohs hardness of 5.5, a melting point of 2800℃, and significant volatilization at 1800–2400℃. Pure periclase is colorless; its color deepens with increasing Fe₂O₃ and CaO content, ranging from yellow to brown to dark brown. The grain size of periclase increases with increasing calcination temperature and holding time, and its resistance to hydration and slag erosion also increases accordingly.

[0003] Existing electric melting furnaces generate an electric arc using three graphite electrodes. The high temperature of this arc melts magnesia. In the production of fused magnesia, the solvent (or flux) is a crucial auxiliary material. Its main functions are to lower the melting point, promote impurity separation, and improve melt flowability, thereby optimizing the melting process and improving the purity and crystal quality of the final fused magnesia. The solvent can chemically react with harmful impurities in the raw materials to generate a molten substance with lower density and a relatively lower melting point—slag. The slag has a low density and floats on the surface of molten MgO. During operation, the sides of the graphite electrodes inevitably come into contact with this slag layer. Furthermore, when the graphite electrodes heat and melt the magnesia, the slag flows towards the graphite electrodes, easily causing significant chemical corrosion to the electrode surface. Therefore, it is necessary to improve existing electric melting furnaces to reduce the chemical corrosion of the graphite electrodes by the slag. Summary of the Invention

[0004] In view of the problems existing in the prior art, the present invention is proposed. Therefore, the object of the present invention is to provide a center-feed electric fused magnesia furnace, which aims to solve the problem that, in the prior art electric fused furnace, the slag causes significant chemical corrosion to the graphite electrodes during the heating and melting of magnesia.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a center-feeding fused magnesia furnace, comprising a furnace base rotatably mounted on a frame, a crucible installed inside the furnace base, a furnace cover detachably mounted on the top of the crucible, and three graphite electrodes mounted on the furnace cover, and further comprising:

[0006] A conveying pipe is vertically inserted through the furnace cover and closed at the bottom. Three connecting pipes are connected through the bottom of the conveying pipe. A connecting pipe is vertically connected through the end of the connecting pipe away from the conveying pipe. The upper end of the connecting pipe is closed. The graphite electrode is correspondingly and coaxially slidably inserted through the upper end of the connecting pipe. A connecting cavity is formed between the periphery of the graphite electrode and the inner wall of the connecting pipe. The furnace cover has an air outlet.

[0007] The jet section is coaxially and rotatably mounted on the lower port of the connecting pipe. The upward-facing side of the jet section has a through groove, and the bottom has multiple oblique holes. The graphite electrode slides through the jet section.

[0008] A rotating unit is provided at the jet section and is used to drive the jet section to rotate.

[0009] As a preferred embodiment of the center-feeding fused magnesia furnace of the present invention, the rotating unit includes a tubular part coaxially fixed to the upward-facing side of the jet section, a rotating conical disk coaxially fixed to the upper end of the tubular part, the outer diameter of the rotating conical disk being smaller than the inner diameter of the connecting pipe, and a plurality of arc-shaped plates fixed to the conical surface of the rotating conical disk.

[0010] In a preferred embodiment of the centrally fed fused magnesia furnace of the present invention, a thermal resistor is installed on the top of the furnace cover.

[0011] As a preferred embodiment of the center-feeding fused magnesia furnace of the present invention, wherein: a guide column is vertically fixed to the top of the furnace base, and the furnace cover is provided with a guide hole for the guide column to pass freely.

[0012] In a preferred embodiment of the centrally fed fused magnesia furnace of the present invention, the conveying pipe is slidably installed through the furnace cover, and a connecting rod is vertically fixed to its lower end, with a hollow plate fixed to the lower end of the connecting rod.

[0013] In a preferred embodiment of the center-feeding fused magnesia furnace of the present invention, a lower limiting ring is fixedly sleeved at the lower end of the conveying pipe, and a first spring is wound around the conveying pipe. The two ends of the first spring elastically abut against the lower limiting ring and the furnace cover, respectively.

[0014] In a preferred embodiment of the centrally fed fused magnesia furnace of the present invention, an upper limit ring is fixedly fitted onto the upper end of the conveying pipe.

[0015] As a preferred embodiment of the center-feeding fused magnesia furnace of the present invention, the connecting rod is fixedly connected to three arc-shaped covers, the arc-shaped covers are coaxial with the graphite electrodes, the notch side of the arc-shaped covers faces the outside of the crucible, the outer arc surface of the arc-shaped covers is provided with a flow guide, and the length direction of the flow guide is tangent to the periphery of the arc-shaped covers.

[0016] In a preferred embodiment of the center-feeding fused magnesia furnace of the present invention, the end of the flow guide away from the arc-shaped cover is connected to a baffle, the flow guide is provided with a reset unit, and the reset unit is used to drive the baffle to move so that the baffle abuts against the surface of the flow guide.

[0017] In a preferred embodiment of the centrally fed fused magnesia furnace of the present invention, the reset unit includes a column vertically fixed to the flow guide, a sliding rod horizontally slidably passing through the upper end of the column, one end of the sliding rod being fixedly connected to a baffle through a connecting column, and a stop ring fixedly fitted on the other end of the sliding rod, and a second spring wrapped around the sliding rod, the two ends of the second spring elastically abutting against the stop ring and the column respectively in the direction of the spring force.

[0018] In summary, the present invention has at least one of the following beneficial effects:

[0019] 1. In this invention, an external inert gas delivery system delivers inert gas to a delivery pipe, then to a connecting pipe via a connecting pipe, and finally into an inclined hole in the jet nozzle through the connecting cavity between the connecting pipe and the graphite electrode. The gas is then sprayed onto the slag surface through the orifice of the inclined hole. Simultaneously, a rotating unit drives the jet nozzle to rotate, thereby causing the inert gas to generate a driving force on the slag near the graphite electrode along the circumferential direction. This causes the slag near the graphite electrode to flow in a circumferential direction, thus creating significant resistance to the movement of the slag towards the graphite electrode. In this flowing state, the reaction time between the slag and the graphite electrode is reduced, thereby reducing the chemical corrosion of the graphite electrode by the slag to a certain extent.

[0020] 2. In this invention, by setting an arc-shaped cover, and the arc-shaped cover being coaxial with the graphite electrode, when the inert gas is injected into the slag, the slag, which is subjected to the thrust of the gas, will be guided by the inner wall of the arc-shaped cover, thereby allowing the slag to flow smoothly in the circumferential direction, thus reducing the contact between the slag and the graphite electrode.

[0021] 3. In this invention, by setting baffles, under the guiding effect of the inner wall of the arc-shaped cover, part of the slag will enter the guiding section and enter between the three arc-shaped covers, and be blocked by the three arc-shaped covers to prevent the slag from approaching the graphite electrode again. In addition, when the inert gas stops blowing on the slag, the baffle can fit against the opening of the guiding section to prevent the slag from entering the middle of the arc-shaped cover from the opening of the guiding section and re-contacting the graphite electrode. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0023] Figure 1 This is a three-dimensional structural diagram of a center-feeding fused magnesia furnace according to the present invention;

[0024] Figure 2 This is a schematic diagram showing the positional relationship of the crucible, furnace cover, and conveying pipe after assembly in this invention;

[0025] Figure 3 for Figure 2 A diagram illustrating the positional relationship from another perspective;

[0026] Figure 4 for Figure 3 Enlarged schematic diagram of the local structure at point A;

[0027] Figure 5 for Figure 3 A schematic diagram showing the positional relationship after omitting the crucible:

[0028] Figure 6 for Figure 5 Another perspective on the positional relationship:

[0029] Figure 7 for Figure 5 Schematic diagram of the explosive decomposition of the medium structure:

[0030] Figure 8 This is a schematic diagram showing the positional relationship of the rotating part, the rotating conical disk, and the tubular part after assembly in this invention;

[0031] Figure 9 for Figure 8 A diagram illustrating the positional relationship from another perspective.

[0032] Explanation of reference numerals in the attached figures:

[0033] 1. Frame; 2. Furnace base; 3. Furnace cover; 4. Resistance temperature detector (RTD); 5. Graphite electrode; 6. Gas outlet; 7. Guide column; 8. Crucible; 9. Conveying pipe; 10. Upper limit ring; 11. First spring; 12. Lower limit ring; 13. Connecting pipe; 14. Arc-shaped cover; 15. Connecting pipe; 16. Column; 17. Sliding rod; 18. Positioning pin; 19. Second spring; 20. Waist-shaped groove; 21. Stop ring; 22. Jet jet section; 23. Guide section; 24. Hollow plate; 25. Connecting rod; 26. Inclined hole; 27. Through groove; 28. Baffle; 29. ​​Arc-shaped plate; 30. Rotating conical disk; 31. Tubular section. Detailed Implementation

[0034] 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.

[0035] This invention discloses a center-feeding fused magnesia furnace.

[0036] Example 1, referring to Figure 1-9 This invention provides a center-feed fused magnesia furnace, comprising a furnace base 2 rotatably mounted on a frame 1 via a bearing housing. A geared motor is mounted on the frame 1, driving the furnace base 2 to rotate. A crucible 8 is installed inside the furnace base 2, and a furnace cover 3 is detachably mounted on the top of the crucible 8. Specifically, multiple guide columns 7 are vertically mounted on the top of the furnace base 2, and guide holes for the guide columns 7 to be inserted into the furnace cover 3. A hoisting device is mounted on the frame 1, driving the furnace cover 3 to move it up and down. A thermal resistor 4 is mounted on the top of the furnace cover 3, with its lower end extending into the crucible 8 for detecting the temperature inside the crucible 8. Three graphite electrodes 5 are mounted on the furnace cover 3, and these three graphite electrodes 5 are electrically connected to an external power supply. Additionally, a conveying pipe 9 is vertically installed on the furnace cover 3. The lower end of the conveying pipe 9 is closed and can slide freely vertically on the furnace cover 3. The lower end of the conveying pipe 9 extends into the crucible 8, and three connecting pipes 15 are fixedly connected in an array along its axial direction. A connecting pipe 13 is vertically fixed to the end of the three connecting pipes 15 away from the conveying pipe 9. The upper end of the connecting pipe 13 is closed. The graphite electrode 5 is correspondingly and coaxially slidably installed on the upper end of the connecting pipe 13. The periphery of the graphite electrode 5 and the inner wall of the connecting pipe 13 form a connecting cavity. The furnace cover 3 has an exhaust port 6. The exhaust port 6 is connected to an external gas recovery device through a pipeline. The external inert gas conveying system is connected to the conveying pipe 9 through a pipeline, so that the inert gas conveying system can convey inert gas into the conveying pipe 9, and then enter the three connecting pipes 13 through the connecting pipes 15, and then enter the connecting cavity formed by the connecting pipes 13 and the graphite electrode 5.

[0037] The lower end of the connecting pipe 13 is coaxially connected to a jet nozzle 22 via a mounting bearing. The jet nozzle 22 is hollow inside and has multiple oblique holes 26 at its bottom. The lower ends of the oblique holes 26 are inclined downwards, and the axis of the oblique holes 26 is perpendicular to the axis of the jet nozzle 22. The upward-facing side of the jet nozzle 22 has multiple through slots 27 penetrating its inner cavity. The graphite electrode 5 slides through the jet nozzle 22. A tubular part 31 is coaxially fixed to the upward-facing side of the jet nozzle 22. The graphite electrode 5 freely passes through the central hole of the tubular part 31. A rotating cone is coaxially fixed to the upper end of the tubular part 31. The outer diameter of the rotating conical disk 30 is smaller than the inner diameter of the connecting pipe 13. Multiple arc-shaped plates 29 are fixed to the conical surface of the rotating conical disk 30. After entering the connecting pipe 13, the inert gas enters the gap between the periphery of the rotating conical disk 30 and the connecting pipe 13 through the connecting cavity, then enters the through-slot 27 of the jet nozzle 22 through the gap, and then enters the inner cavity of the jet nozzle 22 through the through-slot 27. Subsequently, it is sprayed obliquely onto the slag surface in the crucible 8 through multiple inclined holes 26, thereby generating a thrust on the slag. A connecting rod 25 is vertically fixed to the lower end of the conveying pipe 9, and a connecting rod 25 is fixed to the lower end of the connecting rod 25. The hollow plate 24 is designed to be buoyed by the fluid inside the crucible 8 and rises and falls with the fluid level. This allows the hollow plate 24 to drive the longitudinal movement of the conveying pipe 9, and keeps the longitudinal height of the jet nozzle 22 and the slag within a relatively fixed range. This ensures that the inert gas blowing effect on the slag is maintained at a good level. In addition, a lower limit ring 12 is fixedly sleeved on the lower end of the conveying pipe 9, and a first spring 11 is wound around the conveying pipe 9. The two ends of the first spring 11 elastically abut against each other in the direction of the elastic force. The lower limit ring 12 and the furnace cover 3 are elastically resisted by the first spring 11, so that when the conveying pipe 9 moves upward, the first spring 11 can accumulate elastic potential energy. When the liquid level in the crucible 8 drops, the elastic potential energy accumulated by the first spring 11 is quickly released and drives the lower limit ring 12 to move downward, so that the conveying pipe 9 can move downward and reset. The upper end of the conveying pipe 9 is also fixedly fitted with an upper limit ring 10, which is used to limit the downward movement of the conveying pipe 9 and prevent the conveying pipe 9 from detaching from the furnace cover 3.

[0038] Three arc-shaped covers 14 are fixedly connected to the connecting rod 25. The arc-shaped covers 14 are coaxial with the graphite electrode 5. The notch side of the arc-shaped cover 14 faces the outside of the crucible 8. A flow guide 23 is provided on the outer arc surface of the arc-shaped cover 14. The length direction of the flow guide 23 is tangent to the periphery of the arc-shaped cover 14. The flow guide 23 is hollow inside and open at the bottom, so that the longitudinal section of the flow guide 23 is approximately U-shaped. A baffle 28 is connected to the end of the flow guide 23 away from the arc-shaped cover 14. A column 16 is vertically fixed to the upward side of the flow guide 23. A sliding rod 17 is horizontally slidably inserted at the upper end of the crucible 8. One end of the sliding rod 17 is fixedly connected to the baffle 28 via a connecting column, and a stop ring 21 is fixedly fitted onto the other end of the sliding rod 17. A second spring 19 is wound around the sliding rod 17. The two ends of the second spring 19 elastically abut against the stop ring 21 and the column 16 respectively in the direction of the spring force. Inert gas is blown from the inclined hole 26 onto the slag surface of the crucible 8, thereby generating a thrust on the slag and allowing the slag to flow. During the flow, the slag near the graphite electrode 5 will be subjected to the inner arc surface of the arc-shaped cover 14. The guiding effect causes the slag to flow in a circumferential direction, allowing it to flow circumferentially around the graphite electrode 5. During this flow, some slag enters the inner cavity of the guide section 23 and exerts a pushing force on the baffle 28, causing the baffle 28 to move away from the guide section 23. This allows the slag in the inner cavity of the guide section 23 to enter the space between the three arc-shaped covers 14 through the opening of the guide section 23, where it is blocked by the three arc-shaped covers 14, preventing the slag from approaching the graphite electrode 5 again. The slag near electrode 5 is blown by inert gas, causing it to flow in a circumferential direction, thereby reducing its contact with the graphite electrode 5. The slag gradually enters the space between the three arc-shaped covers 14 from the guide section 23, further reducing the contact between the slag and the graphite electrode 5. This can at least reduce the chemical corrosion of the graphite electrode 5 to a certain extent. In addition, the wall of the column 16 is provided with a positioning pin 18, and the surface of the sliding rod 17 is provided with a waist-shaped groove 20 for the positioning pin 18 to be inserted. The positioning pin 18 slides freely in the waist-shaped groove 20.

[0039] The working principle of this embodiment is as follows: Magnesia raw materials, additives, and other raw materials are put into the central area of ​​crucible 8, and preferably the magnesia raw materials, additives, and other raw materials are located between the three graphite electrodes 5. This allows the graphite electrodes 5 to uniformly heat and melt the magnesia raw materials, additives, and other raw materials. After the feeding is completed, the hoisting equipment hoists the furnace cover 3 on the top of crucible 8, and the guide column 7 passes through the guide hole accordingly, so that the furnace cover 3 is installed on the top of crucible 8. Then, the external control cabinet is started, and the power supply equipment supplies power to the graphite electrodes 5, so that the graphite electrodes 5 discharge to generate an electric arc, and heat and melt the magnesia raw materials. During the heating and melting, the additives will react with impurities to form slag. The slag will float upward under the action of buoyancy and float on the surface of the liquid in the crucible 8.

[0040] The hollow plate 24 is buoyed by the fluid inside the crucible 8 and rises and falls with the fluid level. This allows the hollow plate 24 to drive the conveying pipe 9 longitudinally, maintaining the longitudinal height of the jet 22 and the slag within a relatively fixed range. The external inert gas conveying system is activated, delivering inert gas (such as argon) through pipelines to the conveying pipe 9. The inert gas then enters the conveying pipe 9 via the connecting pipe 15 and then into the three connecting pipes 13, and finally into the graphite electrode. When the inert gas comes into contact with the arc-shaped plate 29 in the connected cavity formed by the pole 5, it will impact the arc-shaped plate 29, thereby causing the arc-shaped plate 29 to rotate under the impact force of the inert gas, and driving the rotating cone disk 30 to rotate. When the rotating cone disk 30 rotates, it will drive the tubular part 31 and the jet part 22 to rotate. At the same time, the inert gas will enter the through groove 27 of the jet part 22 through the gap between the periphery of the rotating cone disk 30 and the inner wall of the connecting pipe 13, and then enter the inner cavity of the jet part 22 through the through groove 27. Subsequently, it will be blown obliquely to the slag surface through the multiple oblique holes 26 of the jet part 22.

[0041] In this embodiment, the lower surface of the arc-shaped cover 14 extends below the liquid surface of the fluid in the crucible 8. Inert gas is blown circumferentially towards the slag, causing the slag to be continuously subjected to the blowing force of the inert gas, thus enabling the slag to flow circumferentially. Additionally, the slag is guided by the inner arc surface of the arc-shaped cover 14, flowing along it. That is, the slag will flow circumferentially near the graphite electrode 5. During this flow, some slag will enter the inner cavity of the guide section 23 and exert a pushing force on the baffle 28, causing the baffle 28 to overcome the resistance of the second spring 19 to the stop ring 21. The elastic resisting force causes the baffle 28 to move away from the guide section 23, thereby opening the opening of the guide section 23. This allows the slag to enter between the three arc-shaped covers 14 and be blocked by the three arc-shaped covers 14, preventing the slag from approaching the graphite electrode 5 again. The inert gas continuously generates a blowing force on the slag, which in turn allows the slag to move away from the graphite electrode 5. During the circumferential flow of the slag, it can carry away the reactants and impurities on the surface of the graphite electrode 5, thereby extending the service life of the graphite electrode 5 and reducing the replacement frequency of the graphite electrode 5.

[0042] It should be noted that in this embodiment, all components that come into direct contact with the fluid inside the crucible 8 are made of high-temperature resistant materials.

[0043] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A center-fed fused magnesia furnace, comprising a furnace base (2) rotatably mounted on a frame (1), a crucible (8) installed inside the furnace base (2), a furnace cover (3) detachably mounted on the top of the crucible (8), and three graphite electrodes (5) mounted on the furnace cover (3), characterized in that, Also includes: The conveying pipe (9) is vertically inserted through the furnace cover (3) and closed at the bottom. The lower end of the conveying pipe (9) is connected to three connecting pipes (15). The end of the connecting pipe (15) away from the conveying pipe (9) is vertically connected to a connecting pipe (13). The upper end of the connecting pipe (13) is closed. The graphite electrode (5) is correspondingly and coaxially slidably inserted through the upper end of the connecting pipe (13). The periphery of the graphite electrode (5) and the inner wall of the connecting pipe (13) form a connecting cavity. The furnace cover (3) is provided with an exhaust port (6). The jet section (22) is coaxially rotatably mounted on the lower port of the connecting pipe (13). The upward-facing side of the jet section (22) has a through groove (27), and the bottom has multiple oblique holes (26). The graphite electrode (5) slides through the jet section (22). A rotating unit is provided on the jet section (22) and is used to drive the jet section (22) to rotate.

2. The center-feed fused magnesia furnace according to claim 1, characterized in that, The rotating unit includes a tubular part (31) coaxially fixed to the upward side of the jet part (22). A rotating cone disk (30) is coaxially fixed to the upper end of the tubular part (31). The outer diameter of the rotating cone disk (30) is smaller than the inner diameter of the connecting pipe (13). Multiple arc-shaped plates (29) are fixed to the conical surface of the rotating cone disk (30).

3. The center-feed fused magnesia furnace according to claim 1, characterized in that, A thermal resistor (4) is installed on the top of the furnace cover (3).

4. The center-feed fused magnesia furnace according to claim 1, characterized in that, The furnace base (2) is vertically fixed to the top of a guide column (7), and the furnace cover (3) has a guide hole for the guide column (7) to pass through freely.

5. The center-feed fused magnesia furnace according to claim 1, characterized in that, The conveying pipe (9) is slidably inserted through the furnace cover (3), and a connecting rod (25) is vertically fixed at its lower end. A hollow plate (24) is fixed at the lower end of the connecting rod (25).

6. The center-feed fused magnesia furnace according to claim 5, characterized in that, The lower end of the conveying pipe (9) is fixedly fitted with a lower limit ring (12), and the conveying pipe (9) is wrapped with a first spring (11). The two ends of the first spring (11) elastically abut against the lower limit ring (12) and the furnace cover (3) respectively.

7. The center-feed fused magnesia furnace according to claim 5, characterized in that, The upper end of the conveying pipe (9) is fixedly fitted with an upper limit ring (10).

8. The center-feed fused magnesia furnace according to claim 5, characterized in that, The connecting rod (25) is fixed with three arc-shaped covers (14). The arc-shaped covers (14) are coaxial with the graphite electrode (5). The notch side of the arc-shaped cover (14) faces the outside of the crucible (8). The outer arc surface of the arc-shaped cover (14) is provided with a flow guide (23). The length direction of the flow guide (23) is tangent to the periphery of the arc-shaped cover (14).

9. The center-feed fused magnesia furnace according to claim 8, characterized in that, The end of the flow guide (23) away from the arc-shaped cover (14) is connected to a baffle (28). The flow guide (23) is provided with a reset unit, which is used to drive the baffle (28) to move so that the baffle (28) abuts against the surface of the flow guide (23).

10. The center-fed fused magnesia furnace according to claim 9, characterized in that, The reset unit includes a column (16) vertically fixed to the guide section (23). A sliding rod (17) is horizontally slidably inserted at the upper end of the column (16). One end of the sliding rod (17) is fixed to the baffle (28) through a connecting column. A stop ring (21) is fixedly fitted at the other end of the sliding rod (17). A second spring (19) is wrapped around the sliding rod (17). The two ends of the second spring (19) elastically abut against the stop ring (21) and the column (16) respectively in the direction of the elastic force.

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