A ring-type anode baking furnace

Abstract

This utility model discloses a ring-type anode roasting furnace, relating to the field of roasting furnace technology. The anode roasting furnace includes a furnace body, a flue system, and a combustion system. The flue system is located inside the furnace body and includes flues and baffle walls and brick-pulling structures disposed inside the flues. The baffle walls and brick-pulling structures divide the flues into W-shaped flues, and the upper walls on both sides of the flues have inlet and outlet ports located at both ends of the W-shaped flues, respectively. The combustion system includes oil nozzles extending from the furnace body into the flues. The oil nozzles include a front nozzle located in the middle of the inlet side of the W-shaped flues and a rear nozzle located between the baffle walls. This utility model significantly improves the roasting quality and production efficiency of prebaked anodes by optimizing the flue structure and combustion system.

Description

Technical Field

[0001] This utility model relates to the technical field of electrolytic aluminum industrial equipment, and in particular to a ring-type anode roasting furnace. Background Technology

[0002] In the aluminum electrolysis industry, the quality of prebaked anodes has a decisive impact on the energy consumption, stability, and product quality of the electrolysis process. The anode roasting furnace, as the core equipment in prebaked anode production, directly determines the anode quality. However, traditional ring-type roasting furnaces have the following problems:

[0003] First, uneven temperature distribution and a significant temperature gradient within the fire channel lead to uneven roasting of the anode carbon blocks, poor internal structural stability, and a tendency to generate residual stress, which affects the current distribution and anode consumption during the electrolysis process.

[0004] Second: The average temperature is too low. The average temperature of the fire channel in a traditional roasting furnace is about 1325.8K, which is difficult to meet the requirements of efficient roasting. This extends the roasting cycle to 216-288 hours, increasing energy consumption and production costs.

[0005] Third: Defects in the flue structure, the flue is too thick (220mm), resulting in a large volume and low thermal efficiency; the layout of the retaining wall and brickwork is unreasonable, which easily creates dead corners for flue gas circulation and exacerbates uneven temperature.

[0006] Fourth: Insufficient optimization of operating parameters. Key parameters such as air preheating temperature, air consumption coefficient and fuel distribution ratio have not been precisely controlled, resulting in incomplete fuel combustion, serious energy waste and prominent environmental pollution problems.

[0007] Fifth: High equipment maintenance costs. The traditional roasting furnace body structure is prone to deformation, and the fire channel walls and transverse walls require frequent repairs due to high-temperature burns, increasing downtime and maintenance costs.

[0008] Sixth: Single energy source. Traditional roasting furnaces mainly rely on natural gas as their energy source, resulting in a single energy structure. Against the backdrop of fluctuating energy prices and increasingly stringent environmental protection requirements, they face significant cost pressures and environmental challenges.

[0009] In the existing technology, although the structure and operating parameters of the fire channel have been optimized to some extent through numerical simulation and orthogonal experiments, a systematic new roasting furnace design scheme has not yet been formed, and the innovative application of using photovoltaic microgrids for current Joule thermal coupling of gas to prepare prebaked anodes has not been involved. Utility Model Content

[0010] In view of this, the present invention provides a ring-shaped anode baking furnace, which significantly improves temperature uniformity and average temperature, reduces energy consumption, extends equipment life, and achieves efficient and green production of prebaked anodes by optimizing the fire channel structure and improving the combustion system.

[0011] To achieve the above objectives, this utility model provides the following technical solution:

[0012] A ring-shaped anode baking furnace, comprising:

[0013] Furnace body;

[0014] A flue system is installed inside the furnace body. The flue system includes a flue and a baffle wall and a brick-pulling structure installed inside the flue. The baffle wall and the brick-pulling structure divide the flue into a W-shaped flue. Smoke inlets and smoke outlets are respectively opened on the upper walls on both sides of the flue at both ends of the W-shaped flue.

[0015] The combustion system includes an oil nozzle extending from the furnace body into the fire channel, the oil nozzle comprising a front nozzle located in the middle of the flue gas inlet side of the W-shaped flue and a rear nozzle located between the baffles.

[0016] As a further improvement to the above technical solution, it also includes:

[0017] The smoke exhaust system has a smoke exhaust outlet connected to the outlet of the W-shaped flue via a negative pressure circular pipe;

[0018] A thermal coupling system is used to couple the Joule heating of the electric current with the combustion heat of the gas.

[0019] A waste heat recovery system that uses high-temperature flue gas to preheat the anode and recovers heat from the cooling air;

[0020] The control system is electrically connected to the fire channel system, the combustion system, the smoke exhaust system, the thermal coupling system and the waste heat recovery system, respectively, and the control system is adapted to control and adjust the current and gas supply of the thermal coupling system.

[0021] As a further improvement to the above technical solution, the fire channel includes a square structure formed by side walls and transverse walls; three vertically parallel baffles are arranged at intervals and interlaced between the upper and lower ends of the transverse walls to divide the fire channel into four parts; the brick-pulling structure is evenly distributed between the baffles and the transverse walls near the smoke inlet and the smoke outlet.

[0022] As a further improvement to the above technical solution, the brick-pulling structure has eight pieces, each of which includes long bricks and short bricks, and the dimensions of the long bricks are 220×100×220mm, and the dimensions of the short bricks are 110×100×220mm.

[0023] As a further improvement to the above technical solution, the fuel distribution ratio between the front nozzle and the rear nozzle is 2:1, the air preheating temperature of the combustion system is 1170-1175K, the air consumption coefficient of the combustion system is 1.0-1.4, and the corresponding air velocity of the combustion system is 1.5-1.9m / s.

[0024] As a further improvement to the above technical solution, the thermal coupling system includes:

[0025] Solar photovoltaic panels are installed in an open area near the roasting furnace;

[0026] An energy storage device is electrically connected to the solar photovoltaic panel to store the electrical energy of the solar photovoltaic panel;

[0027] An inverter is electrically connected to both the solar photovoltaic panel and the energy storage device to convert direct current into alternating current.

[0028] Electrodes are disposed between the anode carbon blocks to introduce electrical energy generated by the photovoltaic microgrid into the anode carbon blocks and to use the Joule heat generated by the current passing through the carbon blocks to assist in the roasting process.

[0029] As a further improvement to the above technical solution, the waste heat recovery system includes:

[0030] Multiple furnace chambers are evenly distributed on the outer side of the furnace body;

[0031] A transverse wall of the furnace chamber is provided between adjacent furnace chambers, and both ends of the transverse wall of the furnace chamber are connected to the fire channel;

[0032] A blower is installed above the observation hole at the top of the fire channel via a blower frame. The blower is connected to the transverse wall of the furnace chamber via a pipe. The blower is adapted to blow cooling air into the interior of the transverse wall of the furnace chamber.

[0033] As a further improvement to the above technical solution, the smoke exhaust system includes:

[0034] A flue is located on one side of the fire channel, and one end of the flue is connected to the smoke exhaust port;

[0035] An exhaust fan is connected to the flue. The exhaust fan is adapted to draw high-temperature waste gas through negative pressure and allow it to flow sequentially through multiple furnace chambers. The high-temperature waste gas in the furnace chambers exchanges heat with the cooling air inside the transverse walls of the furnace chambers.

[0036] As a further improvement to the above technical solution, the side wall and the transverse wall are constructed of clay bricks, the thermal conductivity of which is 1.4 + 0.002t (W / (m·K)) and the thickness of which is 100mm; and / or

[0037] The transverse wall is prefabricated from refractory castable blocks, and the dimensions of the transverse wall of the furnace chamber are 3000×500×500mm.

[0038] As a further improvement to the above technical solution, the combustion system further includes a plate heat exchanger, which utilizes the waste heat of flue gas to preheat air; and / or

[0039] The control system also includes a temperature sensor, a pressure sensor, and a flow sensor;

[0040] The oil nozzle is made of high-temperature resistant alloy material, and the downward tilt angle of the oil nozzle is 14-16 degrees.

[0041] Compared with the prior art, this utility model has significant advantages and beneficial effects, specifically reflected in the following aspects:

[0042] 1. The annular anode roasting furnace of this utility model includes a furnace body, a flue system, and a combustion system. The flue system is located inside the furnace body and includes a flue and a brick-pulling structure. Both the baffle wall and the brick-pulling structure are located inside the flue. The baffle wall and the brick-pulling structure divide the flue into a W-shaped flue. Inlet and outlet ports are respectively opened on the upper walls of both sides of the flue at both ends of the W-shaped flue. High-temperature flue gas enters the W-shaped flue through the inlet port, flows back and forth multiple times, and then exits through the outlet port. This path design ensures that heat is fully transferred within the furnace. The combustion system reduces heat loss by extending the flow path of high-temperature flue gas and increasing heat exchange time, thereby improving thermal efficiency. The oil nozzles in the combustion system include front and rear nozzles. The front nozzle is located in the middle of the flue gas inlet side of the W-shaped flue, and the rear nozzle is located between the baffles. This nozzle arrangement can achieve segmented combustion, with the front nozzle responsible for initial combustion and the rear nozzle responsible for supplementary combustion, thereby optimizing the combustion process and improving combustion efficiency. The fuel distribution ratio between the front and rear nozzles determines the distribution of combustion intensity, thus affecting the uniformity of temperature inside the furnace.

[0043] 2. The control system employs a nonlinear multiple regression model to adjust operating parameters (such as air preheating temperature x1, air consumption coefficient x2, and fuel distribution ratio x3) in real time, optimizing the average temperature of the fire channel. By monitoring parameters such as furnace temperature, air preheating temperature, air consumption coefficient, and fuel distribution ratio in real time and dynamically adjusting these parameters, the control system optimizes the average temperature of the fire channel, ensuring the stability and efficiency of the roasting process. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the internal structure of the annular anode roasting furnace in an embodiment of this utility model;

[0045] Figure 2 This is a side view of the annular anode roasting furnace in an embodiment of the present invention.

[0046] Figure 3 This is a system structure block diagram of the annular anode roasting furnace in an embodiment of this utility model.

[0047] Explanation of reference numerals in the attached figures:

[0048] 1-Furnace body;

[0049] 11-Outer shell; 12-Insulation layer;

[0050] 2-Fire system;

[0051] 21-Fire duct; 211-Side wall; 212-Transverse wall; 213-W-type flue; 2131-Smoke inlet; 2132-Smoke outlet;

[0052] 22-Retaining wall;

[0053] 23-Brick-pulling structure; 231-Long brick-pulling structure; 232-Short brick-pulling structure;

[0054] 3-Combustion system; 31-Oil nozzle; 311-Front nozzle; 312-Rear nozzle; 32-Plate heat exchanger;

[0055] 4-Smoke exhaust system; 41-Smoke duct; 42-Exhaust fan;

[0056] 5-Thermal coupling system; 51-Solar photovoltaic panel; 52-Energy storage device; 53-Inverter; 54-Electrode;

[0057] 6- Waste heat recovery system;

[0058] 61-Furnace chamber; 62-Furnace chamber transverse wall; 63-Blower;

[0059] 7-Control system; 71-Temperature sensor; 72-Pressure sensor; 73-Flow sensor. Detailed Implementation

[0060] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings.

[0061] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0062] In the description of this utility model, if there are words such as "several", they mean one or more, "multiple" means two or more, "greater than", "less than", "exceeding" etc. are understood to exclude the number itself, and "above", "below", "within" etc. are understood to include the number itself.

[0063] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0064] Where there is no conflict, the above embodiments and features described herein can be combined with each other.

[0065] like Figure 1-3 As shown, an embodiment of this utility model provides an annular anode calcining furnace, which includes a furnace body 1, a fire channel system 2, and a combustion system 3, wherein:

[0066] The flue system 2 is located inside the furnace body 1. The flue system 2 includes a flue 21 and a brick-pulling structure 23. Both the baffle wall 22 and the brick-pulling structure 23 are located inside the flue 21. The baffle wall 22 and the brick-pulling structure 23 divide the flue 21 into a W-shaped flue 213. The upper walls on both sides of the flue 21 are respectively provided with smoke inlets 2131 and smoke outlets 2132 located at both ends of the W-shaped flue 213. High-temperature flue gas enters the W-shaped flue 213 from the smoke inlet 2131, and after multiple backflows, it is discharged from the smoke outlet 2132. This path design can ensure that heat is fully transferred in the furnace and reduce heat loss. In addition, by extending the flow path of high-temperature flue gas, the heat exchange time is increased, thereby improving thermal efficiency.

[0067] The combustion system 3 includes an oil nozzle 31 extending from the furnace body 1 into the fire channel 21. The oil nozzle 31 includes a front nozzle 311 and a rear nozzle 312. The front nozzle 311 is located in the middle of the flue gas inlet side of the W-shaped flue 213, and the rear nozzle 312 is located between the baffles 22. This arrangement of oil nozzles can realize segmented combustion, in which the front nozzle 311 is responsible for initial combustion and the rear nozzle 312 is responsible for supplementary combustion, thereby optimizing the combustion process and improving combustion efficiency.

[0068] Specifically, in the embodiments of this utility model, the furnace body 1 consists of an outer shell 11 and an insulation layer 12. The outer shell 11 is made of concrete, and the insulation layer 12 is laid inside the outer shell 11. The insulation layer 12 is composed of multiple layers of insulation materials (such as lightweight refractory bricks, aluminum silicate fiber felt, etc.), and the total thickness of the insulation layer 12 is 500mm, which can effectively reduce heat loss. Expansion joints are provided at the bottom of the furnace body 1 with a spacing of 1.5m to avoid thermal expansion deformation. The W-shaped flue 213 can increase the flame travel to 1.5 times the original design, expand the flue gas flow area by 20%, effectively reduce dead zones, and improve temperature uniformity; the flue thickness is optimized from 220mm to 200mm, the volume is reduced by 18%, and the thermal efficiency is increased by 15%.

[0069] The front nozzle 311 is located in the middle of the flue gas inlet side of the W-shaped flue 213 and is used to inject fuel for initial combustion to generate a high-temperature flame; the rear nozzle 312 injects fuel between the baffles for supplementary combustion to further increase the furnace temperature. The fuel distribution ratio (x3) of the front and rear nozzles determines the distribution of combustion intensity, thereby affecting the uniformity of the furnace temperature.

[0070] After final testing, the significant effects achieved by the annular anode roasting furnace in this embodiment in terms of temperature, energy consumption, environmental protection, equipment lifespan, and energy diversification are as follows:

[0071] First, the temperature uniformity is significantly improved. The optimized fire channel temperature standard deviation is reduced from 263.5K to 268.7K, and the temperature uniformity is improved by 30%, ensuring uniform roasting of the anode carbon blocks and stable internal structure.

[0072] Secondly, the average temperature has been significantly increased, with the average temperature of the fire channel rising from 1325.8K to 1486.9K. The roasting cycle has been shortened by 20%, from 216 hours to 173 hours, significantly improving production efficiency.

[0073] Thirdly, energy consumption reduction and environmental benefits: the introduction of photovoltaic microgrid current Joule thermal coupling technology and waste heat recovery system has increased fuel utilization by 25%, reduced unit energy consumption (GJ / t) from 7.5 to 5.0, reduced CO2 emissions by 25%, and reduced NOx emissions by 20%, resulting in significant environmental benefits.

[0074] Fourth, the equipment lifespan is extended. The optimized fire channel structure reduces the burning damage to the baffles and bricks, extending the furnace maintenance cycle to 3 years and reducing maintenance costs by 30%.

[0075] Therefore, through the synergistic effect of the W-shaped flue 213's deflection design and segmented combustion, the temperature distribution inside the furnace is made more uniform, reducing the problem of local overheating or insufficient temperature; the control system 7 further optimizes the temperature distribution by adjusting parameters in real time, ensuring the consistency of the roasting effect; the introduction of the nonlinear multiple regression model realizes the real-time optimization of the roasting process, reduces manual intervention, and improves production efficiency and stability.

[0076] Understandably, the fuel distribution ratio between the front nozzle 311 and the rear nozzle 312 is a key parameter that directly affects combustion intensity and temperature distribution.

[0077] Specifically, please refer to Figure 3 As shown, the annular anode roasting furnace also includes a flue gas system 4, a thermal coupling system 5, a waste heat recovery system 6, and a control system 7, wherein:

[0078] The exhaust outlet of the exhaust system 4 is connected to the outlet of the W-shaped flue 213 via a negative pressure circular pipe. High-temperature flue gas is discharged from the outlet of the W-shaped flue 213 through the negative pressure circular pipe. The negative pressure circular pipe can prevent flue gas leakage and optimize the flue gas flow path to reduce heat loss. The thermal coupling system 5 is electrically connected to the control system 7. The control system 7 is suitable for controlling and adjusting the current and gas supply of the thermal coupling system 5 to achieve coupling of the Joule heat of the current and the heat of gas combustion. The waste heat recovery system 6 uses high-temperature flue gas to preheat the anode and recover the heat of the cooling air.

[0079] Specifically, in this embodiment, the exhaust system 4 uses a negative pressure circular pipe to connect to the outlet of the W-shaped flue 213. The negative pressure design ensures that the flue gas can be discharged efficiently while maintaining the pressure balance inside the furnace. The thermal coupling system 5 provides the synergistic effect of two heat sources by coupling the Joule heat of the current and the combustion heat of the gas. The control system 7 adjusts the current and gas supply of the thermal coupling system 5 in real time to optimize the ratio of Joule heat to combustion heat and ensure the stability and uniformity of the temperature inside the furnace. The waste heat recovery system 6 uses the high-temperature flue gas to preheat the green anode and recovers the heat of the cooling air to achieve the secondary utilization of heat. Before the high-temperature flue gas is discharged, it first preheats the green anode through the waste heat recovery system 6 to reduce the cold input of the green anode into the furnace. The heat of the cooling air is also recovered and used for air preheating or other production processes to further improve thermal efficiency.

[0080] Therefore, the exhaust system 4 maintains the pressure balance inside the furnace through negative pressure, avoiding heat loss or safety hazards caused by excessive pressure; the control system 7 adjusts the current of the thermal coupling system and the gas supply in real time according to the temperature requirements inside the furnace. The Joule heating of the current provides a stable heat input, while the combustion heat of the gas is supplemented as needed. The two work together to ensure the stability and uniformity of the temperature inside the furnace; the waste heat recovery system 6 significantly improves thermal efficiency and reduces energy consumption by preheating the anode and recovering the heat of the cooling air.

[0081] Specifically, in this embodiment, the control system 7 uses a nonlinear multiple regression model to control the operating parameters in real time. The fitting formula of the nonlinear multiple regression model is as follows:

[0082] Y=4.868x1^0.813x2^-0.139x3^0.008

[0083] Where: Y is the average temperature of the flue, x1 is the air preheating temperature, x2 is the air consumption coefficient, and x3 is the fuel distribution ratio between the front nozzle 311 and the rear nozzle 312.

[0084] Specifically, the control system 7 employs a nonlinear multiple regression model to adjust operating parameters (such as air preheating temperature x1, air consumption coefficient x2, and fuel distribution ratio x3) in real time to optimize the average temperature Y of the fire channel. By monitoring parameters such as furnace temperature, air preheating temperature, air consumption coefficient, and fuel distribution ratio in real time and dynamically adjusting these parameters, the control system 7 optimizes the average temperature Y of the fire channel, ensuring the stability and efficiency of the roasting process.

[0085] Specifically, please refer to Figure 1 As shown, the fire passage 21 includes a square structure formed by side walls 211 and transverse walls 212. The square structure provides a stable passage while ensuring the structural strength of the fire passage 21.

[0086] In this embodiment, the side wall 211 is made of four layers of refractory materials of different materials (the inner layer is high alumina brick and the outer layer is heat insulation brick). The total thickness of the side wall 211 is 400mm. The outer side of the side wall 211 is fixed to the furnace shell of the furnace body 1 by pulling bricks. The spacing between the pulling bricks is 0.8m, which reduces heat loss, increases the heating speed, and saves fuel.

[0087] The transverse wall 212 is made of precast refractory castable blocks, with dimensions of 3000×500×500mm. Mechanized installation improves the construction efficiency of the fire channel 21.

[0088] Three vertically parallel baffles 22 are arranged at intervals and are staggered between the upper and lower ends of the horizontal wall 212 to divide the fire channel 21 into four parts. This division method prolongs the flow path of the flue gas, increases the heat exchange time, and improves the thermal efficiency.

[0089] The brick-pulling structure 23 is evenly distributed between the baffle wall 22 and the transverse wall 212 near the smoke inlet 2131 and the smoke outlet 2132, in order to further optimize the flue gas flow path and enhance the heat exchange efficiency.

[0090] In this specific embodiment, the three baffles are vertically and evenly distributed with a spacing of 933mm to ensure uniform airflow in the fire channel 21, and the dimensions of the three baffles 22 are 2800×220×220mm.

[0091] Specifically, please refer to Figure 1 As shown, the brick-pulling structure 23 has eight pieces, each of which includes a long brick 231 and a short brick 232. The long brick 231 has a size of 220×100×220mm, and the short brick 232 has a size of 110×100×220mm.

[0092] In this embodiment, the brick-pulling structure 23 is installed according to the designed position and angle, wherein the long brick-pulling structure 231 is perpendicular to the side wall 211 of the fire channel 21, and the short brick-pulling structure 232 is at a 45-degree angle to the side wall of the fire channel 21. The brick-pulling spacing is adjusted to 200mm to optimize the flue gas flow path.

[0093] Specifically, please refer to Figure 1 As shown, the fuel distribution ratio between the front nozzle 311 and the rear nozzle 312 is 2:1, the air preheating temperature of the combustion system 3 is 1170-1175K, the air consumption coefficient of the combustion system 3 is 1.0-1.4, and the corresponding air velocity of the combustion system 3 is 1.5-1.9m / s.

[0094] During the fuel distribution debugging process, the combustion effect under different fuel distribution ratios (1:1, 1.5:1, 2:1) was tested using flow meters and regulating valves. The final determined fuel distribution ratio between the front nozzle 311 and the rear nozzle 312 was 2:1, at which point the average fire channel temperature was highest, reaching 1486.9 K. Preferably, the air preheating temperature of the combustion system 3 is 1173 K, the air consumption coefficient of the combustion system 3 is 1.2, and the corresponding air velocity of the combustion system 3 is 1.7 m / s.

[0095] Specifically, please refer to Figure 3 As shown, the thermal coupling system 5 includes a solar photovoltaic panel 51, an energy storage device 52, an inverter 53, and an electrode 54, wherein:

[0096] A solar photovoltaic panel 51 is installed in an open area near the roasting furnace; an energy storage device 52 is electrically connected to the solar photovoltaic panel 51 to store the electrical energy of the solar photovoltaic panel 51; an inverter 53 is electrically connected to both the solar photovoltaic panel 51 and the energy storage device 52 to convert direct current into alternating current; electrodes 54 are disposed between the anode carbon blocks to introduce the electrical energy generated by the photovoltaic microgrid into the anode carbon blocks and use the Joule heat generated by the current passing through the carbon blocks to assist in roasting.

[0097] In this embodiment, the thermal coupling system 5 consists of a solar photovoltaic panel 51, an energy storage device 52, an inverter 53, and an electrode 54. The energy storage device 52 is powered by a lithium battery pack. The solar photovoltaic panel 51 converts solar energy into electrical energy, and the energy storage device 52 converts DC power into AC power for energy storage and regulation, providing stable power to the roasting furnace and ensuring a stable power supply.

[0098] Electrodes 54 are set between the anode carbon blocks in the roasting furnace. The electrical energy generated by the photovoltaic microgrid is introduced into the anode carbon blocks. The Joule heat generated by the current passing through the carbon blocks is used to assist the combustion of gas for roasting. The current magnitude and gas supply are adjusted in real time by the control system 7 to achieve the best coupling between the Joule heat of the current and the combustion heat of the gas, thereby improving roasting efficiency and energy utilization.

[0099] As a preferred embodiment, the electrode 54 is made of graphite to ensure good conductivity and high temperature resistance.

[0100] Therefore, by monitoring the fire channel temperature and electrical parameters in real time through the control system 7, the current magnitude and gas supply are adjusted according to the roasting process requirements to achieve the best coupling between the Joule heat of the current and the combustion heat of the gas.

[0101] Specifically, please refer to Figure 3 As shown, the waste heat recovery system 6 includes multiple furnace chambers 61, furnace chamber transverse walls 62, and blowers 63, wherein:

[0102] Multiple furnace chambers 61 are evenly distributed on the outside of the furnace body 1; the furnace chamber transverse walls 62 are set between adjacent furnace chambers 61, and both ends of the furnace chamber transverse walls 62 are connected to the fire channel 21; the blower 63 is installed above the observation hole at the top of the fire channel 21 through the blower frame, and the blower 63 is connected to the furnace chamber transverse wall 62 through the pipe, and the blower 63 is suitable for blowing cooling air into the interior of the furnace chamber transverse wall 62.

[0103] In this embodiment, the waste heat recovery system 6 adopts multiple furnace chambers 61 arranged in sequence. A furnace chamber transverse wall 62 is provided between adjacent furnace chambers 61. The two ends of the furnace chamber transverse wall 62 are connected to the fire channel 21. An observation hole is provided at the top of the fire channel 21. A combustion rack and a blower rack are respectively provided above the observation hole. When the high-temperature waste gas flows through multiple furnace chambers 61 in sequence through the negative pressure suction, the waste heat is used to preheat the ultra-high power graphite electrode. The cooled air flows through the negative pressure inside the furnace chamber transverse wall 62 and the air blown in by the blower 63. When it flows through multiple furnace chambers 61, it exchanges heat with the high-temperature product, which cools the product and heats itself. Then it enters the combustion furnace chamber for burning, which improves the heat utilization rate and the roasting temperature.

[0104] Therefore, by testing the flow path and waste heat utilization effect of high-temperature waste gas between multiple furnace chambers 61, the negative pressure suction and blower parameters are adjusted to ensure full utilization of waste heat and improve thermal efficiency.

[0105] Specifically, please refer to Figure 1 , 3 As shown, the exhaust system 4 includes a flue 41 and an exhaust fan 42. The flue 41 is located on one side of the fire channel 21, and one end of the flue 41 is connected to the exhaust port. The exhaust fan 42 is connected to the flue 41 and is adapted to extract the high-temperature waste gas through negative pressure and let it flow through multiple furnace chambers 61 in sequence. The high-temperature waste gas in the furnace chamber 61 exchanges heat with the cooling air inside the furnace chamber transverse wall 62.

[0106] In this embodiment, the flue 41 is designed as a U-shaped structure, made of 3mm thick steel plate, and equipped with expansion joints spaced 5m apart to prevent thermal deformation. The flue gas outlet is connected to the exhaust frame to ensure stable negative pressure.

[0107] In addition, flue 41 adopts a circular cross-section structure with a diameter of 1.5m, lined with lightweight refractory bricks and wrapped with insulation material on the outside to reduce heat loss.

[0108] Specifically, in this embodiment, the side wall 211 and the transverse wall 212 are constructed of clay bricks with a thermal conductivity of 1.4 + 0.002t (W / (m·K)) and a thickness of 100mm; the furnace chamber transverse wall 62 is prefabricated from refractory castable blocks with dimensions of 3000×500×500mm.

[0109] Specifically, please refer to Figure 3 As shown, the combustion system 3 in this embodiment also includes a plate heat exchanger 32. The plate heat exchanger 32 uses the waste heat of the flue gas to preheat the air, ensuring that the preheating temperature is stable at 1173K and the air consumption coefficient is 1.2.

[0110] In another embodiment of this utility model, the control system 7 further includes five temperature sensors 71, three pressure sensors 72, and two flow sensors 73 evenly arranged in the fire channel. The temperature sensors 71 have a measurement accuracy of ±1K, the pressure sensors 72 have a measurement accuracy of ±0.1Pa, and the two flow sensors have a measurement accuracy of ±2%. Through the arrangement of these sensors, the control system 7 can automatically adjust the operating parameters according to the monitored sensor data and use them for the optimization of nonlinear multiple regression models.

[0111] In another embodiment of this utility model, the oil nozzle 31 is made of high-temperature resistant alloy material. The oil nozzle 31 extends 300mm into the fire channel 21 and is tilted downward at an angle of 14-16 degrees, preferably 15 degrees, to ensure that the fuel and air are fully mixed.

[0112] Although the present invention has been disclosed above, its protection scope is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of this disclosure, and all such changes and modifications will fall within the protection scope of this invention.

Claims

1. A ring-type anode roasting furnace, characterized in that, include: Furnace body; A flue system is installed inside the furnace body. The flue system includes a flue and a baffle wall and a brick-pulling structure installed inside the flue. The baffle wall and the brick-pulling structure divide the flue into a W-shaped flue. Smoke inlets and smoke outlets are respectively opened on the upper walls on both sides of the flue at both ends of the W-shaped flue. The combustion system includes an oil nozzle extending from the furnace body into the fire channel. The oil nozzle includes a front nozzle located in the middle of the flue gas inlet side of the W-shaped flue and a rear nozzle located between the baffles. The front nozzle and the rear nozzle are adapted to inject a certain amount of fuel into the fire channel.

2. The ring anode furnace according to claim 1, characterized in that Also includes: The smoke exhaust system has a smoke exhaust outlet connected to the outlet of the W-shaped flue via a negative pressure circular pipe; A thermal coupling system is used to couple the Joule heating of the electric current with the combustion heat of the gas. A waste heat recovery system that uses high-temperature flue gas to preheat the anode and recovers heat from the cooling air; The control system is electrically connected to the fire channel system, the combustion system, the smoke exhaust system, the thermal coupling system and the waste heat recovery system, respectively, and the control system is adapted to control and adjust the current and gas supply of the thermal coupling system.

3. The ring anode furnace according to claim 2, characterized in that: The fire channel includes a square structure formed by side walls and transverse walls; three vertically parallel retaining walls are arranged at intervals and interspersed between the upper and lower ends of the transverse walls to divide the fire channel into four parts; the brick-pulling structure is evenly distributed between the retaining walls and the transverse walls near the smoke inlet and the smoke outlet.

4. The ring anode furnace according to claim 3, characterized in that: The brick-pulling structure has eight pieces, each of which includes long bricks and short bricks. The long bricks are 220×100×220mm in size, and the short bricks are 110×100×220mm in size.

5. The ring anode furnace as claimed in claim 1, characterized in that: The fuel distribution ratio between the front nozzle and the rear nozzle is 2:1, the air preheating temperature of the combustion system is 1170-1175K, the air consumption coefficient of the combustion system is 1.0-1.4, and the corresponding air velocity of the combustion system is 1.5-1.9m / s.

6. The ring anode furnace as claimed in claim 2, characterized in that: The thermal coupling system includes: Solar photovoltaic panels are installed in an open area near the roasting furnace; An energy storage device is electrically connected to the solar photovoltaic panel to store the electrical energy of the solar photovoltaic panel; An inverter is electrically connected to both the solar photovoltaic panel and the energy storage device to convert direct current into alternating current. Electrodes are disposed between the anode carbon blocks to introduce electrical energy generated by the photovoltaic microgrid into the anode carbon blocks and to use the Joule heat generated by the current passing through the carbon blocks to assist in the roasting of the fuel gas.

7. The ring anode furnace as claimed in claim 3, characterized in that: The waste heat recovery system includes: Multiple furnace chambers are evenly distributed on the outer side of the furnace body; A transverse wall of the furnace chamber is provided between adjacent furnace chambers, and both ends of the transverse wall of the furnace chamber are connected to the fire channel; A blower is installed above the observation hole at the top of the fire channel via a blower frame. The blower is connected to the transverse wall of the furnace chamber via a pipe. The blower is adapted to blow cooling air into the interior of the transverse wall of the furnace chamber.

8. The ring anode furnace according to claim 7, characterized in that: The smoke extraction system includes: A flue is located on one side of the fire channel, and one end of the flue is connected to the smoke exhaust port; An exhaust fan is connected to the flue. The exhaust fan is adapted to draw high-temperature waste gas through negative pressure and allow it to flow sequentially through multiple furnace chambers. The high-temperature waste gas in the furnace chambers exchanges heat with the cooling air inside the transverse walls of the furnace chambers.

9. The ring anode furnace as claimed in claim 7, characterized in that: The side walls and the transverse walls are constructed of clay bricks with a thermal conductivity of 1.4 + 0.002 t (W / (m·K)) and a thickness of 100 mm; and / or The transverse wall is prefabricated from refractory castable blocks, and the dimensions of the transverse wall of the furnace chamber are 3000×500×500mm.

10. The ring anode furnace as claimed in claim 2, characterized in that: The combustion system further includes a plate heat exchanger that utilizes waste heat from the flue gas to preheat air; and / or The control system also includes a temperature sensor, a pressure sensor, and a flow sensor; The oil nozzle is made of high-temperature resistant alloy material, and the downward tilt angle of the oil nozzle is 14-16 degrees.

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