Bottom electrode device and DC arc furnace

Abstract

The present invention discloses a bottom electrode device and a DC arc furnace, which relate to the field of metallurgical technology. The bottom electrode device is located below the top cathode and is connected to the bottom of the furnace shell through an insulating plate. It includes a bottom electrode body with a top plate and a bottom plate, which divides the airflow space between the top plate and the bottom plate into a plurality of partitioned air duct structures in the circumferential direction. The device has a plurality of solid contact pins fixed on the top plate, a contact pin assembly of a plurality of first and second hollow contact pins respectively equipped with thermometers and flow meters passing through the top plate and the bottom plate and fixed on the bottom plate, and a refractory layer located above the top plate. In this way, the solid contact pins of the present invention are only connected to the top plate, which facilitates the arrangement of the air duct structure in the airflow space; the thermometer can reflect the temperature changes of various areas of the furnace bottom in real time, and the flow meter can detect whether the erosion of the refractory layer has reached the allowable limit, effectively preventing and controlling risks.

Description

Technical Field

[0001] The present invention relates to the field of metallurgy technology, and in particular to a bottom electrode device. The present invention also relates to a DC electric arc furnace. Background Art

[0002] At present, the electrode system of a DC arc furnace consists of a top cathode and a bottom anode. The top cathode is generally a graphite electrode, and the bottom anode mainly includes four types: a conductive furnace bottom, a rod-type bottom electrode, a steel sheet-type bottom electrode, and a needle-type bottom electrode. The contact pin of the needle-type bottom electrode generally passes through two support plates, and an air-cooling channel is formed between the two support plates to cool the contact pin. Due to the large number of contact pins, the partitions of the air-cooling channel are difficult to arrange. In the prior art, the contact pins are divided into two parts, inside the furnace and outside the furnace. The contact pins inside the furnace are connected to the conductive plate inside the furnace, and the contact pins outside the furnace are connected between the conductive plates inside and outside the furnace. The double-row arrangement of the contact pins limits the installation space of the temperature measuring device, making it difficult to accurately measure the temperature of some contact pins inside the furnace. There is a risk of overheating of some contact pins, thereby causing steel leakage. Summary of the Invention

[0003] The purpose of the present invention is to provide a bottom electrode device, which solves the problem that the existing technical solutions cannot take into account both the convenience of air cooling channel arrangement and the accurate detection of the temperature of the contact pins in key parts, and enhances the cooling effect by setting an electrode partition. At the same time, a second hollow contact pin is set to detect the erosion of the refractory layer to the limit state, thereby improving the safety of steelmaking. Another purpose of the present invention is to provide a DC arc furnace.

[0004] The above-mentioned purpose of the present invention can be achieved by adopting the following technical solutions:

[0005] A bottom electrode device comprising:

[0006] The bottom electrode body comprises a top plate and a bottom plate which are spaced apart from each other, and a wind passage space is formed between the top plate and the bottom plate;

[0007] a contact pin assembly located on the inner side of the bottom electrode body, the contact pin assembly comprising a plurality of solid contact pins connected to the top plate, and a plurality of first hollow contact pins passing through the top plate and fixed to the bottom plate;

[0008] The air duct structure is located in the air flow space, and the air duct structure has a plurality of air ducts arranged along the circumferential direction of the bottom electrode body. At least one electrode separator is provided in each of the air ducts, and at least one electrode separator is connected between the top plate and the bottom plate.

[0009] In a specific embodiment, multiple first hollow contact pins are evenly arranged radially outward from the center of the bottom electrode body, the first hollow contact pins have a first hollow structure, at least part of the first hollow structure is located above the top plate, and a thermometer is installed in the first hollow structure.

[0010] In a specific embodiment, the contact pin assembly further comprises a plurality of second hollow contact pins passing through the top plate and fixed to the bottom plate, and the plurality of second hollow contact pins are spaced apart from the plurality of first hollow contact pins.

[0011] In a specific embodiment, a plurality of the second hollow contact pins are evenly arranged radially outward from the center of the bottom electrode body, the second hollow contact pins have a second hollow structure, and the second hollow structure is externally connected to a flow meter.

[0012] In a specific embodiment, the height of the second hollow structure located above the top plate is greater than the height of the first hollow structure located above the top plate.

[0013] In a specific embodiment, the plurality of solid contact pins are uniformly connected to the top plate radially outward from the center of the bottom electrode body, and the plurality of solid contact pins are respectively staggered with the plurality of first hollow contact pins and the plurality of second hollow contact pins.

[0014] In a specific embodiment, along the direction of gas flow in the airflow space, the air opening of each of the air ducts gradually increases, and the electrode separator is located on the side of the air opening of the air duct where the air opening increases.

[0015] In a specific embodiment, the air duct structure further includes: the air duct structure has a plurality of intermediate electrode separators, the intermediate electrode separators are connected between the top plate and the bottom plate, and the air duct is formed between two adjacent intermediate electrode separators.

[0016] In a specific embodiment, the bottom plate is provided with an air inlet hole, the air inlet hole is connected to a conductive tube, and the conductive tube is connected to the air flow space through the air inlet hole.

[0017] In a specific embodiment, it also includes: a duct partitioning column is passed through the conductive tube, one end of the duct partitioning column passes through the conductive tube and is connected to the top plate, an annular space is formed between the duct partitioning column and the conductive tube, and a plurality of inner partitions are arranged at intervals along the circumferential direction of the annular space, and the duct inlet formed between two adjacent inner partitions is connected to the duct.

[0018] In a specific embodiment, it further includes: a power connection board is fixed on the outer side of the conductive tube, and the power connection board is electrically connected to the workshop power supply through a connecting cable.

[0019] In a specific embodiment, the bottom electrode device further includes a refractory layer located above the top plate, and the plurality of solid contact pins and the plurality of the first hollow contact pins are inserted into the refractory layer.

[0020] A direct current arc furnace, comprising:

[0021] a furnace shell, wherein a top cathode is provided in the furnace shell;

[0022] The bottom electrode device described above is located in the furnace shell and connected to the furnace bottom of the furnace shell. The bottom electrode device is located below the top cathode.

[0023] In a specific embodiment, the furnace shell further includes: a connecting hole is opened at the bottom of the furnace shell, an inserting tube is connected to the periphery of the top plate, the inserting tube is located in the connecting hole, and the bottom plate is located in the inserting tube.

[0024] In a specific embodiment, the DC arc furnace further includes an insulating plate, and the insulating plate is located between the furnace bottom and the top plate around the connecting hole.

[0025] The contact pin assembly of the bottom electrode device further comprises a plurality of second hollow contact pins passing through the top plate and fixed to the bottom plate, and an annular gap is left between the first hollow contact pins and the second hollow contact pins and the top plate.

[0026] The characteristics and advantages of the present invention are:

[0027] 1. The solid contact pins are only connected to the top plate, which reduces the number of contact pins between the top plate and the bottom plate and facilitates the arrangement of the air duct structure in the air flow space.

[0028] 2. A thermometer is installed in the hollow part of the lower part of the first hollow stylus to accurately monitor the stylus temperature and reflect the temperature changes of various areas on the furnace bottom.

[0029] 3. The hollow part at the bottom of the second hollow contact needle is connected to a flow meter to ensure that when the erosion thickness of the refractory layer reaches the limit value, the flow meter equipped with a switch alarm function will sound an alarm, shut down the furnace in time, and reduce safety hazards.

[0030] 4. The electrode separator is located on the enlarged side of the air outlet of each air duct, dividing the air duct into multiple paths, so that the cold air is evenly distributed and the cooling effect is improved.

[0031] 5. The inner partition, the intermediate electrode partition and the electrode partition can all conduct current. The air duct structure formed by the arrangement of the three can not only make the air duct more reasonable, but also provide better current channel selection.

[0032] 6. An annular gap is left between the first hollow contact pin and the second hollow contact pin and the top plate. Harmful liquid in the scrap steel can flow into the air duct through the annular gap. Along the direction of gas flow in the air duct, the harmful liquid is discharged from the inside of the insertion tube with the wind, protecting the insulation effect of the insulation board from being affected. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0034] Figure 1 Schematic diagram of a DC arc furnace and its bottom electrode device in a new furnace state according to the present invention;

[0035] Figure 2 Schematic diagram of the bottom electrode device and its refractory material of the present invention being corroded to a limit state;

[0036] Figure 3a This is a partial enlarged view of the DC arc furnace and its bottom electrode device in a new furnace state according to the present invention;

[0037] Figure 3b is a partial enlarged view of the annular gap between the first hollow contact pin and the top plate of the present invention;

[0038] Figure 4 A schematic diagram of a DC arc furnace and a bottom electrode device thereof according to the present invention;

[0039] Figure 5 It is a BB cross-sectional view of the DC arc furnace and the bottom electrode device thereof of the present invention.

[0040] Description of Figure Numbers:

[0041] 1. Bottom electrode body; 10. Air passage space; 11. Top plate; 110. Annular gap; 12. Bottom plate; 121. Air inlet; 13. Conductive tube; 14. Air duct partition column; 15. Power board; 16. Backing plate; 17. Positioning piece; 18. Baffle; 19. Air supply device;

[0042] 2. Stylus assembly; 21. Solid stylus; 22. First hollow stylus; 220. First hollow structure; 221. Thermometer; 23. Second hollow stylus; 230. Second hollow structure; 231. Flowmeter; 232. Gas pipeline;

[0043] 3. Air duct structure; 30. Air duct inlet; 31. Air duct; 32. Electrode separator; 33. Intermediate electrode separator; 34. Inner separator;

[0044] 4. Refractory layer;

[0045] 5. Furnace shell; 51. Connection hole;

[0046] 6. Top cathode;

[0047] 7. Insertion tube; 70. Discharge channel;

[0048] 8. Insulation board;

[0049] 9. Fasteners. DETAILED DESCRIPTION

[0050] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0051] Implementation Method 1

[0052] like Figures 1 to 5 As shown, the present invention provides a bottom electrode device, comprising:

[0053] The bottom electrode body 1 has a top plate 11 and a bottom plate 12 spaced apart from each other, and a wind passage space 10 is formed between the top plate 11 and the bottom plate 12;

[0054] The contact pin assembly 2 is located on the inner side A0 of the bottom electrode body 1. The contact pin assembly 2 comprises a plurality of solid contact pins 21 connected to the top plate 11, and a plurality of first hollow contact pins 22 passing through the top plate 11 and fixed to the bottom plate 12.

[0055] The air duct structure 3 is located in the air flow space 10. The air duct structure 3 has multiple air ducts 31 arranged along the circumferential direction of the bottom electrode body 1. At least one electrode separator 32 is provided in each air duct 31. At least one electrode separator 32 is connected between the top plate 11 and the bottom plate 12.

[0056] In the bottom electrode device of the present invention, the solid contact pin 21 is connected to the top plate 11, and is not connected to the bottom plate 12, thereby reducing the number of contact pins between the top plate 11 and the bottom plate 12 and facilitating the arrangement of the air duct structure 3 in the air passage space 10; at the same time, a first hollow contact pin 22 on which a detection tool can be installed is provided to facilitate monitoring of the steelmaking conditions in the furnace; in addition, the electrode partition 32 provided in the air duct 31 divides the air duct 31 into multiple paths, so that the cold air is evenly distributed and the cooling effect is improved.

[0057] Specifically, such as Figures 1 to 5 As shown, the bottom electrode body 1 of the bottom electrode device has a top plate 11 and a bottom plate 12. The bottom plate 12 is located below the top plate 11 and is parallel to and spaced apart from the top plate 11. The space between the top plate 11 and the bottom plate 12 is a wind passage space 10.

[0058] The contact pin assembly 2 of the bottom electrode device is located on the inner side A0 of the bottom electrode body 1. The contact pin assembly 2 includes a plurality of solid contact pins 21 connected to the top plate 11 at intervals, and a plurality of first hollow contact pins 22 arranged at intervals passing through the top plate 11 and the bottom plate 12 and fixed to the bottom plate 12. The plurality of solid contact pins 21 and the plurality of first hollow contact pins 22 are staggered with each other.

[0059] The air duct structure 3 of the bottom electrode device is located in the air flow space 10 formed between the top plate 11 and the bottom plate 12. The air duct structure 3 has a plurality of air ducts 31 evenly arranged along the circumferential direction of the bottom electrode body 1. Each air duct 31 is provided with at least one electrode partition 32 near the edge of the bottom plate 12. The electrode partition 32 divides the air duct 31 into multiple paths, so that the cold air is evenly distributed, thereby improving the cooling effect of the cold air on the contact pin assembly 2. At least one electrode partition 32 is connected between the top plate 11 and the bottom plate 12. In this embodiment, the upper end face and the lower end face of the electrode partition 32 are respectively connected to the lower surface of the top plate 11 and the upper surface of the bottom plate 12 and are used to conduct current.

[0060] According to one embodiment of the present invention, a plurality of first hollow contact pins 22 are evenly arranged radially outward from the center of the bottom electrode body 1, and the first hollow contact pins 22 have a first hollow structure 220, at least part of the first hollow structure 220 is located above the top plate 11, and a thermometer 221 is installed in the first hollow structure 220.

[0061] In this embodiment, the thermometer 221 is installed in the first hollow structure 220 of the first hollow contact pin 22, and can monitor the temperature of the contact pin in real time, thereby reflecting the temperature changes of various areas of the furnace bottom B0 and preventing and controlling the risk of steel leakage.

[0062] Specifically, such as Figures 1 to 5 As shown, multiple first hollow contact pins 22 pass through the top plate 11 and the bottom plate 12 and are fixed on the bottom plate 12. The multiple first hollow contact pins 22 are evenly arranged radially outward from the center of the bottom electrode body 1. The central lower space of the first hollow contact pins 22 is a first hollow structure 220 for installing a thermometer 221. At least part of the first hollow structure 220 is located above the top plate 11, that is, along the inner side A0 direction of the bottom electrode body 1, at least part of the first hollow structure 220 penetrates the inner side of the top plate 11. In this embodiment, the thermometer 221 monitors the temperature of the first hollow contact pins 22 in real time and feeds back the temperature to the steelmaking industrial control computer.

[0063] According to one embodiment of the present invention, the stylus assembly 2 further includes a plurality of second hollow styluses 23 passing through the top plate 11 and fixed to the bottom plate 12 . The plurality of second hollow styluses 23 are spaced apart from the plurality of first hollow styluses 22 .

[0064] In this embodiment, in addition to the first hollow contact pin 22, the bottom electrode device is also provided with a second hollow contact pin 23, which provides a safe and reliable installation space for measuring tools for detecting relevant parameters in the furnace such as temperature and flow, and the present invention does not impose any restrictions on this.

[0065] Further, such as Figure 3a 、 Figure 4 and Figure 5 As shown, a plurality of second hollow contact pins 23 are evenly arranged radially outward from the center of the bottom electrode body 1 . The second hollow contact pins 23 have a second hollow structure 230 , and a flow meter 231 is externally connected to the second hollow structure 230 .

[0066] In this embodiment, the flow meter 231 can realize the leakage detection of the second hollow structure 230 of the second hollow contact needle 23, that is, as the steelmaking progresses, the solid contact needle 21, the first hollow contact needle 22, and the second hollow contact needle 23 begin to melt and consume synchronously and become shorter. When the melting consumption reaches the point where the second hollow structure 230 begins to leak, the flow meter 231 begins to display a positive value, thereby improving the safety of steelmaking.

[0067] Further, such as Figure 3a As shown, the height H2 of the second hollow structure 230 located above the top plate 11 is greater than the height H1 of the first hollow structure 220 located above the top plate 11 .

[0068] In this embodiment, as steelmaking progresses, the solid contact pin 21, the first hollow contact pin 22, and the second hollow contact pin 23 begin to melt and consume shorter parts simultaneously. When the second hollow structure 230 of the second hollow contact pin 23 begins to leak, the flow meter 231 equipped with a switch alarm function can protect the thermometer 221 by promptly giving an alarm.

[0069] Further, such as Figure 4 As shown, multiple solid contact pins 21 are evenly connected to the top plate 11 radially outward from the center of the bottom electrode body 1, and the multiple solid contact pins 21 are staggered with multiple first hollow contact pins 22 and multiple second hollow contact pins 23.

[0070] In this embodiment, the three types of contact pins are arranged in a staggered manner, and the contact pins are kept independent of each other, so the replacement operation is convenient.

[0071] Specifically, such as Figures 1 to 5As shown, the contact pin assembly 2 has a plurality of solid contact pins 21 connected to the top plate 11, a plurality of first hollow contact pins 22 and a plurality of second hollow contact pins 23 passing through the top plate 11 and the bottom plate 12 and fixed on the bottom plate 12. The plurality of solid contact pins 21, the plurality of first hollow contact pins 22, and the plurality of second hollow contact pins 23 are evenly staggered and arranged radially outward from the center of the bottom electrode body 1. In this embodiment, the plurality of solid contact pins 21 are evenly connected to the corresponding top plate 11 directly above the air duct 31, the plurality of first hollow contact pins 22 are evenly arranged in the area of ​​the air duct 31, and the plurality of second hollow contact pins 23 are evenly arranged in the area of ​​the air duct 31 near the center of the bottom plate.

[0072] The central lower space of the second hollow contact pin 23 is a second hollow structure 230 to which an external flow meter 231 is connected. The height of the second hollow structure 230 located above the top plate 11 is greater than the height of the first hollow structure 220 located above the top plate 11. As steelmaking progresses, when the solid contact pin 21, the first hollow contact pin 22, and the second hollow contact pin 23 are synchronously melted and consumed until the second hollow structure 230 of the second hollow contact pin 23 begins to leak, the flow meter 231 equipped with a switch alarm function displays a positive value and issues an alarm, and the furnace is shut down for inspection and further treatment measures are taken to protect the thermometer 221 from high temperature damage. In this embodiment, the bottom of the contact pin of the second hollow contact pin 23 is connected to a compressed air or other suitable gas pipeline 232, and the flow meter 231 is connected to the end of the gas pipeline 232.

[0073] According to one embodiment of the present invention, along the direction of gas flow in the airflow space 10 , the air opening of each air duct 31 gradually increases, and the electrode separator 32 is located on the side of the air duct 31 where the air opening increases.

[0074] In this embodiment, the cold air diffuses faster as the air outlet gradually increases, achieving comprehensive and rapid contact between the cold air and the object to be cooled, thereby ensuring a cooling effect.

[0075] Further, such as Figure 5 As shown, the air duct structure 3 has a plurality of intermediate electrode separators 33 . The intermediate electrode separators 33 are connected between the top plate 11 and the bottom plate 12 , and an air duct 31 is formed between two adjacent intermediate electrode separators 33 .

[0076] In this embodiment, the electrode separators 32 divide the air ducts 31 formed between two adjacent intermediate electrode separators 33 into multiple paths, so that the cold air passing through each air duct 31 is evenly distributed, thereby improving the cooling effect.

[0077] Specifically, such as Figure 1 、 Figure 3a and Figure 5As shown, multiple electrode separators 32 and multiple intermediate electrode separators 33 are evenly spaced along the circumferential direction of the bottom electrode body 1. The electrode separators 32 and the intermediate electrode separators 33 are connected between the top plate 11 and the bottom plate 12. The intermediate electrode separators 33 adjacent to each other divide the air flow space 10 into multiple air ducts 31. Along the wind direction of the gas flow in the air flow space 10, the air outlet of each air duct 31 gradually increases. The electrode separator 32 is located on the air outlet increasing side of the air duct 31, that is, the electrode separator 32 is located on the bottom plate 12. At the edge, the electrode separator 32 divides the air duct 31 into many parts, so that the air cooling is evenly distributed and the cooling effect is enhanced. In this embodiment, the upper and lower end faces of the electrode separator 32 and the intermediate electrode separator 33 are respectively connected to the lower surface of the top plate 11 and the upper surface of the bottom plate 12 and are used to conduct current. The electrode separator 32 and the intermediate electrode separator 33 are both made of arc-shaped low-carbon steel plates with a thickness of 5mm to 15mm. The relative positions of the electrode separator 32, the intermediate electrode separator 33 and the top plate 11 and the bottom plate 12 are fixed and unique.

[0078] According to one embodiment of the present invention, Figure 2 As shown, an air inlet hole 121 is opened on the bottom plate 12 , and a conductive tube 13 is connected to the air inlet hole 121 . The conductive tube 13 is connected to the air flow space 10 through the air inlet hole 121 .

[0079] In this embodiment, cold air enters from the inner cavity of the conductive tube 13 and passes into the air flow space 10 through the air inlet holes 121 on the bottom plate 12 .

[0080] Further, such as Figure 1 and Figure 3a As shown, a duct partition column 14 is provided in the conductive tube 13, and one end of the duct partition column 14 passes through the conductive tube 13 and is connected to the top plate 11. An annular space is formed between the duct partition column 14 and the conductive tube 13, and a plurality of inner partitions 34 are arranged at intervals along the circumferential direction of the annular space. The duct inlet 30 formed between two adjacent inner partitions 34 is connected to the duct 31.

[0081] In this embodiment, cold air is passed into the corresponding air duct 31 through the air duct inlet 30 formed between two adjacent inner partitions 34, and then divided into multiple paths through the electrode partition 32 to cool the first hollow contact pin 22, the second hollow contact pin 23, the inner partition 34, the middle electrode partition 33, the electrode partition 32, the top plate 11, and the bottom plate 12.

[0082] Further, such as Figure 1 As shown, a power board 15 is fixed to the outside of the conductive tube 13, and the power board 15 is electrically connected to the workshop power supply through a connecting cable.

[0083] In this embodiment, the bottom electrode device enables the workshop to quickly obtain power through the power connection plate 15 thereon.

[0084] Specifically, such as Figures 1 to 3a 、 Figure 5 As shown, an air inlet hole 121 is opened on the base plate 12, and a conductive tube 13 is connected to the air inlet hole 121. In this embodiment, the inner cavity of the conductive tube 13 is connected to the air inlet hole 121, the conductive tube 13 is connected to the lower surface of the base plate 12, and the bottom of the conductive tube 13 is connected to the external air supply device 19.

[0085] An air duct partition column 14 is passed through the conductive tube 13, and one end of the air duct partition column 14 passing through the conductive tube 13 is connected to the lower surface of the top plate 11. An annular space is formed between the air duct partition column 14 and the conductive tube 13. A plurality of inner partitions 34 are arranged at intervals along the circumferential direction of the annular space. The air duct inlet 30 formed between two adjacent inner partitions 34 is connected to the corresponding air duct 31. The cold air supplied by the external air supply device 19 enters the air duct from the air duct inlet 30, cools the first hollow contact pin 22, the second hollow contact pin 23, the inner partition 34, the intermediate electrode partition 33, the electrode partition 32, the top plate 11, and the bottom plate 12, and is discharged from the outside of the bottom plate 12. The flow direction of the cold air after entering the air duct inlet 30 is as follows: Figure 1 、 Figure 2 As shown by the middle arrow, in this embodiment, the inner end face of the inner partition 34 is connected to the outer surface of the air duct partition column 14, the lower part of the outer end face of the inner partition 34 is connected to the inner surface of the conductive tube 13, and the upper part of the outer end face of the inner partition 34 is connected to the inner end face of the intermediate electrode partition 33, that is, the intermediate electrode partition 33 extends outward from the inner partition 34 to the edge of the bottom plate 12 and connects the top plate 11 and the bottom plate 12 up and down, and the tail of the air duct inlet 30 formed between two adjacent inner partitions 34 is connected to the air duct 31.

[0086] A power board 15 is fixed to the outside of the conductive tube 13. The power board 15 is electrically connected to the workshop power supply through a connecting cable to draw power. After power is turned on, the current is first conducted from the conductive tube 13 to the inner partition 34 and the bottom plate 12, and then from the inner partition 34 and the bottom plate 12 to the intermediate electrode partition 33 and the electrode partition 32, and finally conducted to the solid contact pin 21 through the top plate 11. The current return conduction route is the opposite.

[0087] According to one embodiment of the present invention, the bottom electrode device further includes a refractory layer 4 located above the top plate 11 , and a plurality of solid contact pins 21 and a plurality of first hollow contact pins 22 are inserted into the refractory layer 4 .

[0088] In this embodiment, as the charge melts, the refractory layer 4 enters an erosion state. When the erosion amount of the refractory layer 4 reaches a limit value, the furnace is shut down for inspection and further treatment measures are taken to improve steelmaking safety and reduce the maintenance cost of steelmaking equipment.

[0089] Specifically, such as Figures 1 to 3aAs shown, the refractory layer 4 is located above the top plate 11, and multiple contact pins of the contact pin assembly 2 are inserted into the refractory layer 4, that is, multiple solid contact pins 21, multiple first hollow contact pins 22, and multiple second hollow contact pins 23 are inserted into the refractory layer 4. The lengths of the solid contact pins 21, the first hollow contact pins 22, and the second hollow contact pins 23 located above the top plate 11 at least cover the thickness of the refractory layer 4. In this embodiment, as the charge melts, the refractory layer 4 enters an erosion state, and the top ends of the solid contact pins 21, the first hollow contact pins 22, and the second hollow contact pins 23 are in a molten state. As the steelmaking proceeds, the thickness of the refractory layer 4 decreases, and the solid contact pins 21, the first hollow contact pins 22, and the second hollow contact pins 23 are in a molten state. The length of the two hollow contact pins 23 becomes shorter, among which the shortening amount of the solid contact pin 21, the first hollow contact pin 22 and the second hollow contact pin 23 is synchronized with the thickness erosion amount of the refractory layer 4. When the erosion thickness of the refractory layer 4 is within the allowable range, the length of the second hollow contact pin 23 is sufficient to ensure that the second hollow structure 230 is in a sealed state and the gas flow is zero. When the erosion thickness of the refractory layer 4 exceeds the allowable value, the top of the second hollow contact pin 23 is eroded to the second hollow structure 230, causing gas leakage therein. The flow meter 231 with a switch alarm function installed outside the second hollow contact pin 23 begins to display a positive value and issues an alarm, and the furnace is shut down for inspection and further treatment measures are taken.

[0090] Implementation Method 2

[0091] like Figure 1 and Figure 2 As shown, the present invention also provides a DC arc furnace, comprising:

[0092] A furnace shell 5, wherein a top cathode 6 is provided in the furnace shell 5;

[0093] The bottom electrode device described in the first embodiment is located inside the furnace shell 5 and connected to the furnace bottom B0 of the furnace shell 5 . The bottom electrode device is located below the top cathode 6 .

[0094] The DC arc furnace of the present invention adopts the bottom electrode device in the first embodiment as the bottom anode, which is convenient for the arrangement of the air cooling channel and can accurately detect the temperature of the contact pins in key positions. An electrode partition 32 is provided to divide the multiple air ducts into multiple channels to enhance the cooling effect. At the same time, a second hollow contact pin 23 is provided to detect when the erosion of the refractory layer reaches the limit state, thereby improving the safety of steelmaking.

[0095] Specifically, such as Figure 1 and Figure 2 As shown, a DC arc furnace includes a furnace shell 5, a top cathode 6 located in the furnace shell 5, and the bottom electrode device as described above, wherein the bottom electrode device is located in the furnace shell 5 and connected above the furnace bottom B0 of the furnace shell 5, and the bottom electrode device is located below the top cathode 6.

[0096] According to one embodiment of the present invention, a connecting hole 51 is opened in the furnace bottom B0 of the furnace shell 5 , an insert tube 7 is connected to the periphery of the top plate 11 , the insert tube 7 is located in the connecting hole 51 , and the bottom plate 12 is located in the insert tube 7 .

[0097] Further, such as Figure 1 As shown, the DC arc furnace further includes an insulating plate 8 , which is located between the furnace bottom B0 and the top plate 11 around the connecting hole 51 .

[0098] Further, such as Figures 1 to 3b As shown, the contact pin assembly 2 of the bottom electrode device further includes a plurality of second hollow contact pins 23 passing through the top plate 11 and fixed to the bottom plate 12 , and an annular gap 110 is left between the first hollow contact pins 22 and the second hollow contact pins 23 and the top plate 11 .

[0099] In this embodiment, the harmful liquid flows into the air duct through the annular gap 110 and is discharged from the inside of the insertion tube 7 along the flow direction of the gas in the air duct with the wind, thereby protecting the insulating effect of the insulating plate 8 from being affected.

[0100] Specifically, such as Figures 1 to 3b As shown, a connecting hole 51 is opened outward from the center of the furnace bottom B0 of the furnace shell 5, and an insertion tube 7 is connected to the lower periphery of the top plate 11. The insertion tube 7 is located in the connecting hole 51, and the bottom plate 12 is located in the insertion tube 7. A discharge channel 70 for harmful liquids is formed between the outer side of the bottom plate 12 and the inner cavity of the insertion tube 7.

[0101] In this embodiment, the DC arc furnace also includes an insulating plate 8 for preventing short circuit between the bottom electrode device and the furnace shell 5. The insulating plate 8 is located between the furnace bottom B0 and the top plate 11 around the connecting hole 51, wherein the insulating plate 8 is laid between the furnace bottom B0 of the furnace shell 5 and the pad 16 of the bottom electrode device. The furnace shell 5, the pad 16, and the insulating plate 8 are fixed by fasteners 9. The pad 16 is located below the bottom electrode body 1 and is connected to the lower surface of the top plate 11. The pad 16 and the bottom electrode body 1 are connected by a plurality of positioning members 17 that maintain the relative position of the two unchanged. The positioning members 17 are positioning pins that can accurately position the bottom electrode device and are easy to remove and replace.

[0102] In this embodiment, the contact pin assembly 2 of the bottom electrode device also has a plurality of second hollow contact pins 23 passing through the top plate 11 and fixed to the bottom plate 12. An annular gap 110 is left between the first hollow contact pin 22 and the second hollow contact pin 23 and the top plate 11. A circle of baffles 18 is connected to the upper edge of the bottom electrode body 1. Harmful substances in the scrap steel are concentrated on the inner side of the baffle 18 above the top plate 11. If the harmful substances melt, they will flow directly into the air duct 31 through the annular gap 110 and be blown away by the wind, thereby protecting the insulating effect of the insulating plate 8 from being affected.

[0103] In this embodiment, the installation process of the bottom electrode device is as follows:

[0104] An insulating plate 8 is laid on the furnace bottom B0 of the furnace shell 5 , and then a backing plate 16 of the bottom electrode device is installed on the insulating plate 8 , and the three are firmly fixed by fasteners 9 .

[0105] Fix the baffle 18, solid contact pin 21, top plate 11, inner partition 34, intermediate electrode partition 33, electrode partition 32 and bottom plate 12, and then install the first hollow contact pin 22, thermometer 221, second hollow contact pin 23, gas pipeline 232, flow meter 231 and remaining parts to form an assembly.

[0106] Place the above-mentioned assembly parts on the installed pad 16 and connect them through the positioning parts 17. After ensuring that they are correct, build the refractory layer 4.

[0107] Finally, the power board 15 of the bottom electrode device is connected to the workshop power supply, the external air supply device 19 is installed in place, and after the temperature measurement and other related work are prepared, the power can be turned on for steelmaking.

[0108] During the steelmaking process, the temperature of the first hollow contact pin 22 is monitored in real time. If the temperature is abnormal, the furnace is stopped for inspection. If relevant parts of the bottom electrode device need to be replaced, the bottom electrode device can be pushed upward to perform relevant work. After the maintenance and inspection are correct, the bottom electrode device is installed according to the above process.

[0109] During the steelmaking process, the gas flow in the second hollow contact needle 23 is monitored in real time. If there is a gas leak at the upper part of the second hollow structure 230, the flow meter 231 equipped with a switch alarm function will change from zero to a positive value and issue an alarm, and the furnace will be shut down for inspection and further treatment measures will be taken.

[0110] The above descriptions are only several embodiments of the present invention. Those skilled in the art may make various changes or modifications to the embodiments of the present invention based on the contents disclosed in the application documents without departing from the spirit and scope of the present invention.

Claims

1. A bottom electrode device, characterized in that: include: The bottom electrode body comprises a top plate and a bottom plate which are spaced apart from each other, and a wind passage space is formed between the top plate and the bottom plate; a contact pin assembly located on the inner side of the bottom electrode body, the contact pin assembly comprising a plurality of solid contact pins connected to the top plate, and a plurality of first hollow contact pins passing through the top plate and fixed to the bottom plate; an air duct structure located in the air passage space, the air duct structure comprising a plurality of air ducts arranged along the circumferential direction of the bottom electrode body, at least one electrode separator being disposed in each of the air ducts, and at least one electrode separator being connected between the top plate and the bottom plate; A plurality of first hollow contact pins are evenly arranged radially outward from the center of the bottom electrode body, the first hollow contact pins have a first hollow structure, at least a portion of the first hollow structure is located above the top plate, and a thermometer is installed in the first hollow structure; Along the wind direction of the gas flow in the wind passage space, the air opening of each air duct gradually increases, and the electrode separator is located on the side of the air opening of the air duct where the air opening increases.

2. The bottom electrode device according to claim 1, characterized in that The contact pin assembly further comprises a plurality of second hollow contact pins passing through the top plate and fixed to the bottom plate, wherein the plurality of second hollow contact pins are spaced apart from the plurality of first hollow contact pins.

3. The bottom electrode device according to claim 2, characterized in that A plurality of the second hollow contact pins are evenly arranged radially outward from the center of the bottom electrode body, the second hollow contact pins have a second hollow structure, and the second hollow structure is externally connected to a flow meter.

4. The bottom electrode device according to claim 3, characterized in that A height of the second hollow structure located above the top plate is greater than a height of the first hollow structure located above the top plate.

5. The bottom electrode device according to claim 2, characterized in that The plurality of solid contact pins are uniformly connected to the top plate radially outward from the center of the bottom electrode body, and the plurality of solid contact pins are respectively staggered with the plurality of first hollow contact pins and the plurality of second hollow contact pins.

6. The bottom electrode device according to claim 1, wherein: The air duct structure has a plurality of intermediate electrode separators, which are connected between the top plate and the bottom plate, and the air duct is formed between two adjacent intermediate electrode separators.

7. The bottom electrode device according to claim 1, wherein: An air inlet hole is provided on the bottom plate, and a conductive tube is connected to the air inlet hole. The conductive tube is communicated with the air passage space through the air inlet hole.

8. The bottom electrode device according to claim 7, characterized in that An air duct partition column is provided in the conductive tube, and one end of the air duct partition column passes through the conductive tube and is connected to the top plate. An annular space is formed between the air duct partition column and the conductive tube. A plurality of inner partitions are arranged at intervals along the circumferential direction of the annular space, and the air duct inlet formed between two adjacent inner partitions is connected to the air duct.

9. The bottom electrode device according to claim 7, characterized in that A power board is fixed on the outside of the conductive tube, and the power board is electrically connected to the workshop power supply through a connecting cable.

10. The bottom electrode device according to claim 1, wherein: The bottom electrode device further includes a refractory layer located above the top plate, and a plurality of the solid contact pins and a plurality of the first hollow contact pins are inserted into the refractory layer.

11. A DC arc furnace, characterized in that: include: a furnace shell, wherein a top cathode is provided in the furnace shell; The bottom electrode device according to any one of claims 1 to 10 is located in the furnace shell and connected to the furnace bottom of the furnace shell, and the bottom electrode device is located below the top cathode.

12. The DC arc furnace according to claim 11, characterized in that: A connecting hole is opened at the bottom of the furnace shell, an inserting tube is connected to the periphery of the top plate, the inserting tube is located in the connecting hole, and the bottom plate is located in the inserting tube.

13. The DC arc furnace according to claim 12, characterized in that: The DC arc furnace further includes an insulating plate located between the furnace bottom and the top plate around the connection hole.

14. The DC arc furnace according to claim 11, characterized in that The contact pin assembly of the bottom electrode device further comprises a plurality of second hollow contact pins passing through the top plate and fixed to the bottom plate, and an annular gap is left between the first hollow contact pins and the second hollow contact pins and the top plate.

Images