Graphite electrode with combined cooling structure

Abstract

The invention discloses a graphite electrode with a combined cooling structure. The graphite electrode comprises an electrode body and an electrode contact, the electrode body is a graphite electrode, a central through hole is formed in the electrode body, and the electrode contact is fixedly assembled at the upper end part of the electrode body; a sealing table top is formed on the lower surface of the electrode contact, and a conduit and an annular seat are formed on the sealing table top; the upper part of the conduit is connected with an air supply pipe through an electrode joint; the annular base is provided with a hollow structure cavity, the upper portion of the hollow structure cavity is connected with a water supply pipe through an electrode connector, and water outlet holes communicated with the hollow structure cavity are evenly formed in the annular face of the bottom of the annular base. And the electrode contact is provided with a discharge hole for discharging cooling gas and cooling water at the same time on the sealing table surface and between the guide pipe and the annular seat. The invention solves the limitation of the traditional cooling mode, and can obviously improve the cooling efficiency and prolong the service life of the graphite electrode.

Description

Technical Field

[0001] The invention relates to the technical field of graphite electrodes, in particular to a graphite electrode with a combined cooling structure. Background Art

[0002] Carbon graphite products are non-metallic materials composed of carbon elements. They have excellent electrical conductivity, thermal conductivity, high temperature resistance, corrosion resistance, and self-lubrication. They are widely used in many fields such as metallurgy, machinery, electronics, chemical industry, nuclear energy, and aerospace. As a type of carbon graphite product, graphite electrodes are usually made of artificial graphite and are widely used in electric arc furnaces. They convert electrical energy into heat energy through arc discharge or resistance heating, thereby achieving melting of materials in the furnace and promoting chemical reactions.

[0003] As consumables, graphite electrodes are consumed mainly due to breakage, oxidation, erosion by slag and furnace gas. Due to the high temperature and highly corrosive working environment in the electric arc furnace, the surface and internal temperature of the graphite electrode will rise rapidly. The continuous high temperature state will accelerate the oxidation process on the surface of the graphite electrode, which will not only weaken its electrical conductivity and thermal conductivity, but also further affect its structural stability and service life. In addition, under high temperature conditions, graphite electrodes are also subjected to huge thermal stress, which may cause local structural thermal expansion of the electrode material. This phenomenon will also have a negative impact on the service life of the electrode and may cause arc instability, thereby affecting the quality of the smelting process. Under the aforementioned conditions, graphite electrodes need to have good heat resistance and corrosion resistance. In addition, in order to ensure the stable operation of the electric arc furnace and improve production efficiency, an auxiliary cooling structure is also designed to extend the service life of the graphite electrode and improve its working stability in a high temperature environment.

[0004] Traditional graphite electrode cooling methods mostly use single water cooling or air cooling. However, these traditional cooling methods have certain limitations:

[0005] Although the water cooling system has a high cooling efficiency, the water quality requirements for cooling water are relatively strict, and impurities in the working environment of the furnace are prone to blockage of the cooling water channel. In addition, inside the graphite electrode, the fusion speed and heat exchange speed between cold water and hot water are very fast, which causes the newly entered cooling water to not only exchange heat with the graphite electrode, but also quickly mix with the hot water that has completed the heat exchange, thereby significantly reducing the cooling effect and greatly reducing the overall cooling efficiency.

[0006] Although the air cooling system is easy to maintain, its cooling efficiency is relatively low, especially under high load operation, and often cannot fully meet the cooling requirements of graphite electrodes. In addition, the flue gas content in the working environment of the furnace is high, and these flue gases will introduce impurities into the inside of the graphite electrode, causing corrosion, which in turn leads to corrosion problems of the graphite body and joints. Summary of the invention

[0007] The technical problem solved by the present invention is to provide a graphite electrode with a combined cooling structure to solve the defects in the above technical background.

[0008] The technical problem solved by the present invention is achieved by adopting the following technical solutions:

[0009] A graphite electrode with a combined cooling structure, comprising an electrode body and an electrode joint;

[0010] The electrode body is a graphite electrode, and a central through hole is provided inside the electrode body. The central through hole is a straight hole of equal diameter, the lower end of the central through hole is closed, and the top has an open surface; the electrode connector is fixedly assembled at the upper end of the electrode body;

[0011] A sealing table is formed on the lower surface of the electrode connector, and the sealing table matches the top surface of the central through hole, and can seal and close the open surface of the central through hole during assembly; a concentrically arranged conduit and an annular seat are formed in the middle of the sealing table, with the conduit inside and the annular seat outside; the length of the conduit matches the length of the central through hole, and a flow gap is left at the bottom, and the height of the annular seat is 1 / 3 to 1 / 2 of the length of the conduit;

[0012] The conduit is an air cooling channel, and the upper part thereof is connected to the air supply pipe through the electrode joint;

[0013] The annular seat has a hollow structural cavity, the upper part of the hollow structural cavity receives the water supply pipe through the electrode joint, and the annular seat is evenly formed with water outlet holes connected to the hollow structural cavity on the bottom annular surface;

[0014] The electrode joint is located on the sealing table surface at a position corresponding to the gap space between the conduit and the annular seat, and is also provided with a discharge hole for discharging cooling gas and cooling water simultaneously.

[0015] As a further limitation, the electrode connector is formed of a high temperature resistant and corrosion resistant alloy material.

[0016] As a further limitation, when the motor body is composed of a long-sized combined graphite electrode made of multiple graphite electrodes connected in series through electrode joints, the corresponding connecting joints are formed with through holes that match the conduits and annular seats to ensure that the combined graphite electrodes can be smoothly cooled and powered in high-temperature equipment such as electric arc furnaces or induction furnaces.

[0017] As a further limitation, the sealing table surface is a truncated cone structure, and the top surface of the central through hole has a conical docking surface matching the truncated cone structure;

[0018] The sealing table and the central through hole are formed with matching threaded surfaces on the inclined surfaces of the conical butt joint surfaces.

[0019] As a further limitation, a bonding portion is reserved at a position of the electrode joint corresponding to the sealing table surface, so as to facilitate bonding the electrode joint to the electrode body at the bonding portion by an adhesive.

[0020] As a further limitation, the outer surface of the electrode connector is also designed with heat dissipation fins, which can significantly improve the heat dissipation efficiency of the electrode connector, thereby maintaining a lower temperature during long-term operation and extending the service life of the electrode connector.

[0021] As a further limitation, the interior of the electrode connector is designed with a bending flow channel and a hollow capsule cavity connected in series to the bending flow channel, and the bending flow channel is connected between the water supply pipe and the annular seat.

[0022] As a further limitation, the gas supply pipe uses nitrogen or air or inert gas as a gas source, and the gas supply pressure of the gas source is 0.05-0.15 MPa, and the gas supply temperature is 10-30°C;

[0023] When the gas supply pipe uses nitrogen or air as the gas source, the corresponding gas supply pipe is also provided with a tee with a reversing valve, and is connected to an inert gas storage tank through a side branch of the tee; the inert gas storage tank is used to discharge the air and powder impurities in the central through hole before the graphite electrode is heated.

[0024] As a further limitation, the air outlet volume of the conduit per unit time is 5 to 8 times the water outlet volume of the water outlet hole on the annular seat; the air outlet volume of the conduit per second is 1 / 5 to 1 / 2 of the corresponding volume of the central through hole.

[0025] As a further limitation, a gap of 1 / 8 to 1 / 5D is left between the outer side wall of the annular seat and the hole wall of the central through hole on the electrode body, where D is the hole diameter of the central through hole.

[0026] Beneficial effects: The graphite electrode with a combined cooling structure of the present invention realizes the dual cooling effects of air cooling and water cooling through the design of the combined cooling structure, which significantly improves the working stability and service life of the graphite electrode in a high temperature environment; secondly, since the flow rates of cooling gas and cooling water are reasonably controlled, the cooling efficiency is maximized. At the same time, the cooling water in a partially gasified state can play a role of atomization and sealing, avoiding the problem of impurities in the working environment of the furnace entering the central through hole and clogging the cooling water channel, thereby ensuring the long-term stable operation of the cooling system; through reasonable design of the electrode joint to cooperate with the heat dissipation, the service life of the electrode can be further extended and its reliability in long-term work can be ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a structural schematic diagram of a preferred embodiment of the present invention.

[0028] Among them: 1. air supply pipe; 2. discharge hole; 3. water supply pipe; 4. electrode joint; 5. bonding part; 6. electrode body; 7. annular seat; 8. conduit; 9. water outlet hole; 10. central through hole; 11. atomization closed area. DETAILED DESCRIPTION

[0029] In order to make the technical means, creative features, objectives and effects of the present invention easier to understand, the present invention is further described below in conjunction with specific embodiments. The described embodiments are only part of the embodiments of the present invention, not all of them.

[0030] It should be noted that, in the description of the embodiments of the present invention, unless otherwise clearly stipulated and limited, "multiple" means two or more, and the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection, a chemical connection, or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements; for ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0031] See also Figure 1 A preferred embodiment of a graphite electrode with a combined cooling structure is provided, in which the graphite electrode is composed of an electrode body 4 and an electrode connector 6. The electrode body 4 is cylindrical and is made of artificial graphite through a molding process, which ensures the basic performance of the graphite electrode. A central through hole 10 is provided at the inner center of the electrode body 4, and the through hole passes through the length direction of the electrode body 4. The bottom of the central through hole 10 is closed, while the top is open, and an outwardly expanding frustum slope is formed on the open top surface. The electrode connector 6 is made of a high-temperature resistant and corrosion-resistant alloy material (such as a copper alloy) to ensure its stability and durability in high temperature and harsh working environments. Interfaces for connecting to external circuits can be designed on the electrode connector 6 according to actual needs. These interfaces can be threaded interfaces, plug-in interfaces or other forms of electrical connections. This design enables the electrode connector 6 to be easily connected to an external power source or control device, thereby ensuring stable transmission of electrical energy and accurate transmission of control signals.

[0032] In this embodiment, a sealing table is formed at the lower portion of the electrode connector 6, and the sealing table matches the outward-expanded conical conical inclined surface on the top surface of the central through hole 10 on the electrode body 4, and can be pressed and assembled at the top surface of the central through hole 10 by matching the two conical inclined surfaces. In addition, the electrode connector 6 is formed with a circle of adhesive portion 5 on the outer side of the sealing table. By applying glue and then pressing the adhesive portion 5, the connection strength between the electrode connector 6 and the electrode body 4 can be further strengthened, and structural sealing can be achieved.

[0033] In another embodiment, a matching threaded surface may be formed on the inclined surface of the tapered joint surface between the sealing table and the center through hole 10; through this design, the connection between the sealing table and the center through hole 10 is more secure, and can effectively prevent structural loosening due to thermal expansion or mechanical vibration under high temperature and high pressure environment.

[0034] In this embodiment, the electrode joint 6 is provided with an annular seat 7 and a conduit 8 on the lower surface of the sealing table. The conduit 8 is located inside and passes through the central axis of the electrode joint 4 in the assembled state, and the annular seat 7 is concentrically surrounded by the outside of the conduit 8. From the perspective of physical structure, the annular seat 7 not only supports the conduit 8, but also provides additional mechanical strength to resist the impact stress that may be generated when the cooling medium flows. In addition, a gap of 1 / 8 to 1 / 5 times the diameter of the central through hole is left between the outer side wall of the annular seat 7 and the hole wall of the central through hole 10 on the electrode body 6 as a reserved space for the atomization closed area 11. In terms of size structure, the length of the conduit 8 is consistent with the length of the central through hole, and a flow gap is maintained between the bottom and the closed end face of the conduit 8. The height of the annular seat 7 is half the length of the conduit 8. In addition, the annular seat 7 has a hollow structural cavity inside, and a plurality of water outlet holes 9 are evenly distributed on the bottom surface of its annular surface. These water outlet holes 9 are connected to the hollow structural cavity on the inside and can discharge cooling water when pressure is formed in the hollow structural cavity.

[0035] The electrode joint 6 is also provided with a plurality of medium conduits, which include an air supply pipe 1 , a water supply pipe 3 and a discharge hole 2 .

[0036] The gas supply pipe 1 is connected to the central through hole 10 on the inside and is connected to the gas source on the outside. In different embodiments, the corresponding gas source can be nitrogen, air or inert gas. The gas supply pressure of the gas source is 0.05-0.15MPa, and the gas supply temperature is 10-30°C. Through such gas supply parameters, it can be ensured that the cooling gas can flow through the conduit in a high temperature environment, thereby achieving the expected cooling effect. When the corresponding gas source uses nitrogen or air, its effect is slightly worse than that of inert gas. If it is necessary to optimize its use effect, the corresponding gas supply pipe can be connected to a tee with a reversing valve, and the inert gas storage tank can be connected through the side branch of the tee; the inert gas storage tank is used to discharge the air and powder impurities in the central through hole 10 before heating the graphite electrode, and then nitrogen or air is supplied as cooling gas through the reversing valve.

[0037] The water supply pipe 3 is connected to the hollow structural cavity of the annular seat 7 on the inside and to the water cooling system on the outside. The water cooling system is used to provide cooling water, and the water pressure and flow rate of the corresponding cooling water can be adjusted by the water cooling system.

[0038] The discharge hole 2 is connected to the gap space between the conduit and the annular seat on the inner side to ensure that the cooling gas and cooling water can be discharged smoothly to avoid pressure accumulation inside the electrode, thereby protecting the electrode structure from damage.

[0039] In this embodiment, the electrode joint 6 supplies cooling gas and cooling water to the central through hole 10 of the electrode body 6 through the air supply pipe 1 and the water supply pipe 3 at the same time, thereby achieving a dual cooling effect of air cooling and water cooling. Figure 1 The arrow style shown in the figure can achieve the air cooling effect. By adjusting the water output of the water supply pipe 3, part of the water sprayed from the water outlet 9 can be gasified at high temperature and retained in the atomized closed area 11 between the annular seat 7 and the inner wall of the central through hole 10. This process helps to atomize and seal external impurities, effectively preventing impurities in the working environment of the furnace from invading the regional space of the central through hole 10 and avoiding clogging the cooling water channel. Therefore, the long-term stable operation of the cooling system can be ensured. The other part of the water is discharged from the discharge hole 2 with the flow of the cooling gas to achieve heat exchange and discharge. In order to achieve the best use effect, the gas outlet volume per unit time of the conduit 8 is 5 to 8 times the water outlet volume of the water outlet 9 on the annular seat 7; the gas outlet volume per second of the conduit 8 is 1 / 5 to 1 / 2 of the corresponding volume of the central through hole 10. Such a design ratio ensures that the flow rate of cooling gas and cooling water is balanced, while maximizing the cooling effect under the premise of ensuring cost.

[0040] In another embodiment, if the corresponding motor body 6 is a long composite graphite electrode connected in series with multiple sections, a through hole matching the conduit and the annular seat is formed on the corresponding connection joint for connecting adjacent graphite electrodes to ensure that the composite graphite electrode can be smoothly cooled and powered in high-temperature equipment such as an arc furnace or an induction furnace. This design not only improves the service life of the electrode, but also enhances the stability and reliability of the entire system.

[0041] In order to further improve the performance of the electrode connector 6, special treatment techniques can be used on its surface to enhance wear resistance and corrosion resistance. For example, a hard alloy layer can be plated or nitrided to meet the needs of different processing materials and environmental conditions. In addition, the outer surface of the electrode connector 6 can be designed with heat dissipation fins, and its shape, size and layout can be customized according to specific needs to adapt to a variety of working environments and cooling needs. These fins can significantly improve the heat dissipation efficiency, ensure that the electrode connector 6 maintains a low temperature during long-term operation, and thus extend its service life.

[0042] In addition, the internal design of the electrode connector 6 includes a curved flow channel and a hollow capsule connected to the curved flow channel. These hollow capsules are connected to the water supply pipe 3 and the hollow structure cavity of the annular seat 7, ensuring that the water pressure in the hollow structure cavity in the annular seat 3 is maintained. At the same time, using water as a cooling medium can effectively cool the electrode connector 6. Therefore, even in an extremely high temperature environment, the electrode connector can maintain excellent working performance and avoid damage caused by overheating.

[0043] The basic principle, main features and advantages of the present invention are shown and described above. It should be understood by those skilled in the art that the use of these embodiments is only used to illustrate the present invention and is not intended to limit the scope of protection of the present invention. In addition, it should also be understood that after reading the technical content of the present invention, those skilled in the art can make various changes, modifications and / or variations to the present invention, and all of these equivalent forms also fall within the scope of protection defined by the claims attached to this application.

Claims

1. A graphite electrode with a combined cooling structure, characterized in that: It includes an electrode body and an electrode connector; The electrode body is a graphite electrode, and a central through hole is provided inside the electrode body. The central through hole is a straight hole of equal diameter, the lower end of the central through hole is closed, and the top has an open surface; the electrode connector is fixedly assembled at the upper end of the electrode body; A sealing table is formed on the lower surface of the electrode connector, and the sealing table matches the top surface of the central through hole, and can seal and close the open surface of the central through hole during assembly; a concentrically arranged conduit and an annular seat are formed in the middle of the sealing table, with the conduit inside and the annular seat outside; the length of the conduit matches the length of the central through hole, and a flow gap is left at the bottom, and the height of the annular seat is 1 / 3 to 1 / 2 of the length of the conduit; The conduit is an air cooling channel, and the upper part thereof is connected to the air supply pipe through the electrode joint; The annular seat has a hollow structural cavity, the upper part of the hollow structural cavity receives the water supply pipe through the electrode joint, and the annular seat is evenly formed with water outlet holes connected to the hollow structural cavity on the bottom annular surface; The electrode joint is located on the sealing table surface at a position corresponding to the gap space between the conduit and the annular seat, and is also provided with a discharge hole for discharging cooling gas and cooling water simultaneously.

2. The graphite electrode with a combined cooling structure according to claim 1, characterized in that: The electrode connector is formed of a high temperature resistant and corrosion resistant alloy material.

3. The graphite electrode with a combined cooling structure according to claim 1, characterized in that: When the motor body is composed of a long combined graphite electrode in which multiple graphite electrodes are connected in series through electrode joints, a through hole matching the conduit and the annular seat is formed on the corresponding connecting joint.

4. The graphite electrode with a combined cooling structure according to claim 1, characterized in that: The sealing table surface is a truncated cone structure, and the top surface of the central through hole has a conical docking surface matching the truncated cone structure.

5. The graphite electrode with a combined cooling structure according to claim 4, characterized in that: The sealing table and the central through hole are formed with matching threaded surfaces on the inclined surfaces of the conical butt joint surfaces.

6. The graphite electrode with a combined cooling structure according to claim 1, characterized in that: The electrode connector is provided with a bonding portion at a position corresponding to the sealing table surface, so as to facilitate bonding the electrode connector to the electrode body at the bonding portion by means of an adhesive.

7. The graphite electrode with a combined cooling structure according to claim 1, characterized in that: The electrode connector is internally designed with a bending flow channel and a hollow capsule cavity serially connected to the bending flow channel, and the bending flow channel is connected between the water supply pipe and the annular seat.

8. The graphite electrode with a combined cooling structure according to claim 1, characterized in that: The gas supply pipe uses nitrogen, air or inert gas as a gas source, and the gas supply pressure of the gas source is 0.05-0.15MPa, and the gas supply temperature is 10-30°C.

9. The graphite electrode with a combined cooling structure according to claim 8, characterized in that: When the gas supply pipe uses nitrogen or air as the gas source, the corresponding gas supply pipe is also provided with a tee with a reversing valve, and is connected to an inert gas storage tank through a side branch of the tee; the inert gas storage tank is used to discharge the air and powder impurities in the central through hole before the graphite electrode is heated.

10. The graphite electrode with a combined cooling structure according to claim 1, characterized in that: The air outlet volume of the conduit per unit time is 5 to 8 times the water outlet volume of the water outlet hole on the annular seat; the air outlet volume of the conduit per second is 1 / 5 to 1 / 2 of the corresponding volume of the central through hole.

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