Optimized baking device for graphite electrode production for industrial silicon

Abstract

The utility model discloses a kind of optimization baking devices for graphite electrode production for industrial silicon, including supporting base and baking tank body, heating coil layer is equipped in baking tank body inner wall, baking tank body is limited to slide and is equipped with rack structure, baking tank body rear side bottom is equipped with protective gas input pipe, baking tank body rear side top is equipped with waste gas discharge pipe, baking tank body rear side is equipped with pressure sensor and temperature sensor.The utility model has the advantages compared with prior art in that: temperature is accurately controllable: heating coil layer cooperation temperature sensor real-time monitoring, avoid green body " overburning " or " underburning ";Protective gas evenly covers: make protective gas diffuse evenly in tank body, cover all green body surface, oxidation defect rate reduces;Rack stable general: double limit (limiting slide + rotating wheel) design, stability improves, avoid collision breakage when loading and unloading green body;Environment stable controllable: pressure sensor and double flow control valve are cooperatively linked, can accurately maintain micro-positive pressure in tank.

Description

Technical Field

[0001] This utility model relates to the field of graphite electrode production technology, specifically to an optimized calcination device for the production of graphite electrodes for industrial silicon. Background Technology

[0002] As a core conductive component of electric arc furnaces for industrial silicon smelting, the quality of graphite electrodes directly affects smelting efficiency and energy consumption. The calcination process is a crucial step in graphite electrode production. By heat-treating the formed green blank at high temperatures, the binder pitch is carbonized to form a carbon structure with certain strength and conductivity.

[0003] In existing technologies, graphite electrode calcination devices mostly adopt a "batch production" design, which has the following core problems:

[0004] Uneven temperature distribution: The heating elements are mostly integral designs, which cannot achieve precise temperature control in different areas of the tank. This results in large differences in the degree of carbonization in different parts of the graphite electrode blank, with some areas experiencing "overburning" or "underburning". This affects the overall strength and conductivity of the electrode, making it difficult to meet the high-quality requirements of industrial silicon smelting for electrodes.

[0005] Insufficient protective gas coverage: Protective gases (such as nitrogen and argon) are often directly introduced into the tank through a single pipe. The gas flow is concentrated and cannot evenly cover all the green billet surfaces, which can easily lead to local oxidation or carbonization defects in the green billet and reduce the product qualification rate.

[0006] Inconvenient material rack operation: Existing material racks mostly adopt a simple slide rail design, which has poor stability during the pushing and pulling process. Collisions are prone to occur when loading and unloading green blanks in batches, causing damage to the green blanks. In addition, the material rack layer height is fixed, which cannot be adapted to graphite electrode green blanks of different lengths and specifications, resulting in poor versatility.

[0007] Lack of process control: The lack of real-time monitoring and regulation of the pressure inside the tank and the poor exhaust of waste gas can easily lead to abnormal pressure inside the tank, which in turn damages the stability of the roasting environment and further aggravates the fluctuation of the carbonization quality of the green body.

[0008] In view of the shortcomings of the existing technology, there is an urgent need for an optimized calcination device that can achieve precise temperature control, uniform gas distribution, stable loading and unloading, and real-time regulation of the calcination environment, so as to meet the high-quality production requirements of graphite electrodes for industrial silicon. Utility Model Content

[0009] The technical problem to be solved by this utility model is to provide an optimized calcination apparatus for the production of graphite electrodes for industrial silicon, addressing the shortcomings mentioned in the background art.

[0010] To solve the above-mentioned technical problems, the technical solution provided by this utility model is: an optimized calcination device for the production of graphite electrodes for industrial silicon, including a support base, a calcination tank body supported on the top of the support base, a sealing cover structure at the front end of the calcination tank body, and a heating coil layer inside the inner wall of the calcination tank body.

[0011] The roasting tank is equipped with a material rack structure that limits sliding within the body, a protective gas inlet pipe is provided at the bottom rear side of the roasting tank, and a waste gas outlet pipe is provided at the top rear side of the roasting tank.

[0012] The roasting tank is equipped with a pressure sensor and a temperature sensor on the rear side.

[0013] Furthermore, the roasting tank is provided with limiting frames on both sides, the limiting frames are provided with limiting grooves on the outside, and the material rack structure is provided with limiting sliders extending into the limiting grooves on both sides.

[0014] Furthermore, the material rack structure is provided with support columns on the upper and lower rear sides, and a rotating wheel is provided on the outer side of the support columns. The roasting tank is provided with limiting guide rails on the upper and lower sides, and the limiting guide rails are provided with limiting grooves that cooperate with the rotating wheel.

[0015] Furthermore, the protective gas input pipe extends to the bottom of the roasting tank and is provided with a gas distribution pipe, and the top of the gas distribution pipe is provided with multiple gas outlets.

[0016] Furthermore, the exhaust gas discharge pipe is equipped with a first flow control valve, and the protective gas input pipe is equipped with a second flow control valve.

[0017] The advantages of this utility model compared with the prior art are: precise and controllable temperature: the heating coil layer, together with the temperature sensor for real-time monitoring, can ensure that the temperature field stability error in the calcination tank is reduced, avoid the green blank being "over-burned" or "under-burned", make the carbonization degree of the graphite electrode green blank uniform, improve its strength and conductivity, and meet the high-quality requirements of industrial silicon smelting.

[0018] Uniform protective gas coverage: The combination design of protective gas inlet pipe + gas distribution pipe + gas outlet ensures that the protective gas diffuses evenly in the tank, covering all green surface and reducing oxidation defect rate.

[0019] Stable and versatile material rack: The dual limit design (limit slider + rotating wheel) makes the pushing and pulling resistance of the material rack ≤50N, improving stability and avoiding collision damage when loading and unloading green billets;

[0020] Stable and controllable environment: The pressure sensor and dual flow control valve work together to accurately maintain a slight positive pressure inside the tank, ensuring timely discharge of exhaust gas, stability of the roasting environment, and further guaranteeing product quality consistency. Attached Figure Description

[0021] Figure 1 This is a first structural schematic diagram of an optimized calcination apparatus for the production of graphite electrodes for industrial silicon.

[0022] Figure 2 This is a schematic diagram of the second structure of an optimized calcination apparatus for the production of graphite electrodes for industrial silicon.

[0023] Figure 3 This is a side cross-sectional view of an optimized calcination apparatus for the production of graphite electrodes for industrial silicon.

[0024] Figure 4 This is a front sectional view of an optimized calcination apparatus for the production of graphite electrodes for industrial silicon.

[0025] As shown in the figure: 1. Support base; 2. Roasting tank; 3. Sealing cover structure; 4. Heating coil layer; 5. Material rack structure; 6. Support column; 7. Rotating wheel; 8. Limiting guide rail; 9. Protective gas input pipe; 10. Gas distribution pipe; 11. Gas outlet; 12. Waste gas discharge pipe; 13. Pressure sensor; 14. Temperature sensor; 15. First flow control valve; 16. Second flow control valve; 17. Limiting frame; 18. Limiting slide groove; 19. Limiting slider; 20. Limiting groove. Detailed Implementation

[0026] The present invention will now be described in further detail with reference to the accompanying drawings.

[0027] Combined with appendix Figure 1-4 An optimized calcination apparatus for the production of graphite electrodes for industrial silicon includes a support base 1, the top of which is bolted to support a calcination tank 2. The calcination tank 2 is a cylindrical sealed structure with a flange-connected sealing cover 3 at the front end. A high-temperature resistant silicone sealing ring (temperature resistance ≥1200℃) is pasted on the sealing surface of the sealing cover 3, and a manual opening and closing handle is welded to the outside to ensure the sealing performance of the tank. A spirally distributed heating coil layer 4 is embedded in the inner wall of the calcination tank 2, and a temperature sensor 14 is provided on the rear side of the calcination tank 2. The temperature field inside the tank is stabilized by the heating coil layer 4 in conjunction with the temperature sensor 14.

[0028] A protective gas input pipe 9 is installed at the bottom rear side of the roasting tank 2. The protective gas input pipe 9 extends to the bottom of the tank and connects to a gas distribution pipe 10 arranged along the length of the tank bottom. The top of the gas distribution pipe 10 has evenly spaced gas outlet holes 11 with a diameter of 2-5 mm (hole spacing 50 mm) to ensure uniform diffusion of the protective gas. A second flow control valve 16 is installed on the protective gas input pipe 9 to adjust the input flow rate of the protective gas (nitrogen / argon). A waste gas discharge pipe 12 is installed at the top rear side of the roasting tank 2. A first... The flow control valve 15 is used to discharge waste gases such as asphalt fumes generated during the roasting process. The pressure sensor 13 is fixed to the inner wall of the rear side of the roasting tank 2 by a bracket. Both the pressure sensor 13 and the temperature sensor 14 are connected to the PLC control cabinet on the outside of the roasting tank 2 by high-temperature resistant signal cables. The control cabinet is equipped with a 10-inch touch screen, which can display temperature and pressure data in real time and supports parameter setting and over-threshold alarm. At the same time, the PLC control cabinet controls other electrical components in the equipment. This is a common circuit setting, so it will not be described in detail.

[0029] The roasting tank 2 has limiting frames 17 on both sides, and limiting grooves 18 on the outer side of the limiting frames 17. The material rack structure 5 has limiting sliders 19 on both sides that extend into the limiting grooves 18. The material rack structure 5 has support columns 6 on the rear side, and rotating wheels 7 are rotatably provided on the outer side of the support columns 6. The roasting tank 2 has limiting guide rails 8 on the upper and lower sides, and the limiting guide rails 8 have limiting grooves 20 that cooperate with the rotating wheels 7 to form a second layer of limiting.

[0030] The specific implementation method is as follows:

[0031] 1. Assembly steps of the device

[0032] Base and tank installation: Fix the support base 1 horizontally on the ground, and fix the roasting tank 2 to the top of the support base 1 with bolts, ensuring that the vertical deviation of the tank is ≤2mm;

[0033] Heating component installation: The heating coil layer 4 is embedded in the pre-set groove on the inner wall of the roasting tank 2;

[0034] Sealing cap installation: Connect the sealing cap structure 3 to the front end of the roasting tank 2 using flange bolts. Attach a high-temperature resistant silicone sealing ring to the sealing surface, ensuring a leakage rate ≤0.1m after closure. 3 / h;

[0035] Limiting and material rack assembly: Weld limiting frames 17 on both sides inside the roasting tank 2, and weld limiting guide rails 8 on the upper and lower sides of the inner side; Assemble the material rack structure 5, install limiting sliders 19 on both sides of the material rack, install support columns 6 with rotating wheels 7 on the upper and lower sides of the rear side, and adjust the spacing of the carrying plates according to the length of the green body.

[0036] Gas circuit and sensor installation: Insert the protective gas input pipe 9 from the bottom rear side of the tank and connect the pipe end to the gas distribution pipe 10 (ensure that the gas outlet 11 faces upward). Install the second flow control valve 16 on the input pipe. Insert the exhaust gas discharge pipe 12 from the top rear side of the tank and install the first flow control valve 15. Fix the pressure sensor 13 and temperature sensor 14 on the rear side of the tank. Connect the signal cable to the PLC control cabinet and complete the wiring and debugging.

[0037] 2. Actual usage steps

[0038] Green blank loading: Open the sealing cover structure 3 and place the graphite electrode green blank (e.g., 200mm in diameter and 1000mm in length) stably on the carrier plate of the material rack structure 5. Keep the green blank spacing ≥50mm to avoid contact.

[0039] Material rack push in: Push the material rack structure 5 so that the limiting slider 19 slides along the limiting groove 18 and the rotating wheel 7 rolls along the limiting groove 20 until the material rack is completely pushed into the tank. Close the sealing cover and tighten the flange bolts.

[0040] Parameter setting: The calcination process parameters are set via the touch screen of the external PLC control cabinet.

[0041] Temperature curve: room temperature → 200℃ (hold for 2 hours, heating rate 5℃ / min) → 600℃ (hold for 4 hours, heating rate 3℃ / min) → 1000℃ (hold for 6 hours, heating rate 2℃ / min);

[0042] Protective gas flow rate: Nitrogen 5m³ 3 / h;

[0043] Internal pressure: 0.03 MPa;

[0044] Calcination process control:

[0045] The heating coil layer 4 is activated, and the temperature control module adjusts the heating power in real time based on the feedback data from the temperature sensor 14 to ensure that the temperature inside the tank conforms to the set curve.

[0046] The second flow control valve 16 is opened, and the protective gas is evenly filled into the tank through the outlet 11 of the gas distribution pipe 10; the pressure sensor 13 monitors the pressure in real time. If the pressure is >0.035MPa, the control cabinet automatically opens the first flow control valve 15 to discharge the waste gas; if the pressure is <0.025MPa, the first flow control valve 15 is automatically reduced and the opening of the second flow control valve 16 is increased to maintain stable pressure.

[0047] Cooling and unloading: After calcination, turn off the heating coil layer 4, continue to introduce nitrogen until the temperature inside the tank drops to ≤50℃, and close all valves; open the sealing cover, pull out the material rack structure 5, and take out the calcined graphite electrode to complete the production.

[0048] The present invention and its embodiments have been described above. This description is not restrictive, and the accompanying drawings are only one embodiment of the present invention; the actual structure is not limited thereto. In conclusion, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the inventive spirit of the present invention, such designs should fall within the protection scope of the present invention.

Claims

1. An optimized calcination apparatus for the production of graphite electrodes for industrial silicon, comprising a support base (1), wherein a calcination tank (2) is supported on the top of the support base (1), and a sealing cap structure (3) is provided at the front end of the calcination tank (2), characterized in that: The inner wall of the roasting tank (2) is provided with a heating coil layer (4); The roasting tank (2) is equipped with a material rack structure (5) for limiting sliding, and a protective gas input pipe (9) is provided at the bottom rear side of the roasting tank (2), and a waste gas discharge pipe (12) is provided at the top rear side of the roasting tank (2). A pressure sensor (13) and a temperature sensor (14) are provided on the rear side of the roasting tank (2).

2. The optimized calcination apparatus for the production of graphite electrodes for industrial silicon as described in claim 1, characterized in that: The roasting tank (2) is provided with limiting frames (17) on both sides, and the limiting frames (17) are provided with limiting grooves (18) on the outside. The material rack structure (5) is provided with limiting sliders (19) extending into the limiting grooves (18) on both sides.

3. An optimized calcination apparatus for the production of graphite electrodes for industrial silicon as described in claim 1, characterized in that: The material rack structure (5) is provided with support columns (6) on the upper and lower sides of the rear side. The support columns (6) are provided with rotating wheels (7) on the outer side. The roasting tank (2) is provided with limiting guide rails (8) on the upper and lower sides. The limiting guide rails (8) are provided with limiting grooves (20) that cooperate with the rotating wheels (7).

4. An optimized calcination apparatus for the production of graphite electrodes for industrial silicon according to claim 1, characterized in that: The protective gas input pipe (9) extends to the bottom of the roasting tank (2) and is provided with a gas distribution pipe (10). The top of the gas distribution pipe (10) is provided with multiple gas outlets (11).

5. An optimized calcination apparatus for the production of graphite electrodes for industrial silicon according to claim 1, characterized in that: The exhaust gas discharge pipe (12) is equipped with a first flow control valve (15), and the protective gas input pipe (9) is equipped with a second flow control valve (16).

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