Circulating system of submerged arc furnace

Abstract

The utility model discloses a circulating system of a submerged arc furnace, which relates to the technical field of non-ferrous metal processing, the circulating system of the submerged arc furnace comprises a furnace body, a main air pipe, an air seal fan, a circulating pipeline and a processing device, the furnace body comprises a reaction layer and a discharge layer arranged at the bottom of the reaction layer; the main air pipe is mounted at the top of the reaction layer; one end of the main air pipe is communicated with the reaction layer; the gas seal fan is communicated with the other end of the main air pipe and is used for conveying gas into the reaction layer; one end of the circulating pipeline is communicated with the discharge layer, and the other end is communicated with the air seal fan; the treatment device is communicated with the reaction layer and is used for treating flue gas. According to the technical scheme provided by the utility model, the purpose of reducing the construction cost of the submerged arc furnace can be achieved, meanwhile, the generation amount of oxynitride during metal smelting can be reduced, and the operation cost of the submerged arc furnace can be reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of nonferrous metal processing, in particular to a circulation system of a submerged arc furnace. Background Art

[0002] Submerged arc furnaces, also known as electric arc furnaces or resistance furnaces, are primarily used for reducing and smelting raw materials such as ores, carbonaceous reducing agents, and solvents. During the metal smelting process, air must be continuously introduced into the furnace to lower the temperature. However, nitrogen and oxygen in the air continuously generate nitrogen oxides at high temperatures. Flue gas containing large amounts of nitrogen oxides requires treatment before release into the atmosphere. Therefore, multiple flue gas treatment systems are often required outside the furnace, resulting in high overall construction and operating costs.

[0003] In view of this, it is necessary to provide a submerged arc furnace circulation system to solve or at least alleviate the above technical problems. Utility Model Content

[0004] The main purpose of the utility model is to provide a circulation system for an ore-bearing furnace, aiming to solve the technical problem of high construction and operation costs of the ore-bearing furnace.

[0005] To achieve the above-mentioned purpose, the present invention provides a submerged arc furnace circulation system, comprising:

[0006] A furnace body, comprising a reaction layer and a furnace discharge layer arranged at the bottom of the reaction layer;

[0007] A main air duct, the main air duct being installed on the top of the reaction layer, one end of the main air duct being in communication with the reaction layer;

[0008] an air-sealing blower, the air-sealing blower being connected to the other end of the main air duct and being used for delivering gas to the reaction layer;

[0009] a circulation pipe, one end of which is connected to the furnace discharge layer, and the other end of which is connected to the gas seal blower;

[0010] A processing device is communicated with the reaction layer and is used for processing the flue gas.

[0011] In one embodiment, the circulation pipeline includes an air inlet pipe, an air supply pipe and an air inlet flow control valve. One end of the air inlet pipe is connected to the furnace discharge layer, and the other end is connected to one end of the air supply pipe. The other end of the air supply pipe is connected to the air seal blower, and the air inlet flow control valve is arranged on the air inlet pipe.

[0012] In one embodiment, the circulation pipeline further includes an outlet air flow control valve, and the outlet air flow control valve is arranged at one end of the air supply pipe close to the air sealing blower.

[0013] In one embodiment, the circulating pipeline further includes a monitoring component, and the monitoring component includes a temperature sensor, a pressure sensor, and a flow sensor. The pressure sensor is disposed at one end of the intake pipe close to the tapping layer, and the temperature sensor and the flow sensor are spaced apart and disposed at one end of the gas transmission pipe close to the gas seal fan.

[0014] In one embodiment, the intake pipe includes an inlet section and a transition section. The inlet section includes a pipe housing and a refractory layer, and the refractory layer is disposed on the inner wall surface of the pipe housing;

[0015] One end of the inlet section is communicated with the tapping layer, and the other end is communicated with one end of the transition section. The other end of the transition section is communicated with the gas transmission pipe.

[0016] In one embodiment, the submerged arc furnace circulating system further includes an air inlet pipe. The gas seal fan includes an air inlet and an air outlet. The air inlet pipe is communicated with the air inlet, the main air pipe is communicated with the air outlet, and the circulating pipeline is communicated with the air inlet.

[0017] In one embodiment, the air inlet pipe includes an air flow control valve, and the air flow control valve is disposed at one end of the air inlet pipe close to the air inlet.

[0018] In one embodiment, the treatment device includes a main flue, an air cooler, a flue gas treatment tower, and a peripheral fan. The main flue is communicated with the reaction layer, and the main flue, the air cooler, the flue gas treatment tower, and the peripheral fan are sequentially communicated.

[0019] In one embodiment, the treatment device further includes a waste heat recovery device. The waste heat recovery device is arranged in parallel with the air cooler. The main flue includes a main pipe, a first branch pipe, and a second branch pipe. One end of the main pipe is communicated with the reaction layer, and the other end is respectively communicated with the first branch pipe and the second branch pipe. A first valve is installed on the first branch pipe, and a second valve is installed on the second branch pipe. The first branch pipe is communicated with the air cooler, the second branch pipe is communicated with the waste heat recovery device, and both the air cooler and the waste heat recovery device are communicated with the flue gas treatment tower.

[0020] In one embodiment, the main pipe includes a smoke hood and a flue pipe. The smoke hood includes a gas collection port and an exhaust port. The gas collection port and the exhaust port are oppositely arranged, and the outer contours of both the gas collection port and the exhaust port are circular. The diameter of the outer contour of the gas collection port is larger than the diameter of the outer contour of the exhaust port;

[0021] The gas collection port is communicated with the reaction layer, the exhaust port is communicated with the flue pipe, and the flue pipe is respectively communicated with the first branch pipe and the second branch pipe.

[0022] In the technical solution provided by the present utility model, the submerged arc furnace circulation system includes a furnace body, a main air duct, an air sealing fan, a circulation pipeline and a treatment device. Among them, the furnace body includes a reaction layer and a tapping layer arranged at the bottom of the reaction layer; the main air duct is installed at the top of the reaction layer, and one end of the main air duct is communicated with the reaction layer; the air sealing fan is communicated with the other end of the main air duct for delivering gas into the reaction layer; one end of the circulation pipeline is communicated with the tapping layer, and the other end is communicated with the air sealing fan; the treatment device is communicated with the reaction layer for treating flue gas. Through this setting, the low-temperature flue gas in the tapping layer is further cooled in the circulation pipeline and then transported to the reaction layer through the air sealing fan and the main air duct, which is used to reduce the temperature of the reaction layer, reduce the entry of cooling air, thereby reducing the input of nitrogen and oxygen in the air, and further reducing the generation amount of nitrogen oxides. This setting enables the tapping layer to not require additional flue gas treatment equipment, reduces the equipment investment cost, simultaneously reduces the generation amount of nitrogen oxides, reduces the cost of flue gas denitrification, and ultimately reduces the construction and operation costs of the submerged arc furnace. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0024] Figure 1 It is a schematic structural diagram of an embodiment of the submerged arc furnace circulation system provided by the present utility model;

[0025] Figure 2 is Figure 1 a partial structural schematic diagram of

[0026] Figure 3 is Figure 1 a schematic diagram of another part of

[0027] Explanation of the reference numerals in the drawings:

[0028] 1000, submerged arc furnace circulation system;

[0029] 1, furnace body; 11, reaction layer; 12, tapping layer;

[0030] 2, main air duct; 21, feeding structure;

[0031] 3, air sealing fan;

[0032] 4. Circulating pipeline; 41. Intake pipe; 411. Inlet section; 412. Transition section; 42. Gas transmission pipe; 43. Intake flow control valve; 44. Outlet flow control valve; 45. Monitoring component; 451. Temperature sensor; 452. Pressure sensor; 453. Flow sensor;

[0033] 5. Processing device; 51. Main flue; 511. Main pipe; 5111. Smoke hood; 5112. Flue pipe; 512. First branch pipe; 513. Second branch pipe; 514. First valve; 515. Second valve; 52. Air cooler; 53. Waste heat recovery device;

[0034] 6. Air inlet pipe.

[0035] The realization, functional features and advantages of the purpose of the present utility model will be further described in conjunction with the embodiments and with reference to the accompanying drawings. Specific embodiments

[0036] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present utility model.

[0037] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of the present utility model, the directional indications are only used to explain the relative positional relationship and movement conditions between components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0038] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present utility model, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. In addition, if "and / or" or "and / or" appears throughout the text, its meaning includes three parallel solutions. Taking "A and / or B" as an example, it includes solution A, solution B, or a solution where A and B are satisfied simultaneously. In addition, the technical solutions between the embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement it. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the protection scope required by the present utility model.

[0039] China is a major country in ore smelting, and the demand for high-quality mineral products in domestic and international markets is growing continuously. The submerged arc furnace is a commonly used device in ore smelting. It is an industrial electric furnace mainly used for reducing and smelting raw materials such as ores, carbonaceous reducing agents, and solvents. It is mainly used for producing ferroalloys such as ferrosilicon, ferromanganese, ferrochrome, ferrotungsten, and silicomanganese alloys, as well as chemical raw materials such as calcium carbide.

[0040] In the industrial metal smelting industry, in the fierce market competition, enterprises need to continuously reduce production costs, improve product quality and environmental protection levels to enhance competitiveness. With the increasing global attention to environmental protection, pollution emissions in industrial production are strictly regulated. The submerged arc furnace can work continuously, and a large amount of flue gas will be generated during the working process. The flue gas usually contains pollutants such as carbon monoxide, sulfur oxides, and nitrogen oxides, which cannot meet the emission standards. Therefore, at least two sets of flue gas purification devices are usually installed outside the furnace body of the submerged arc furnace to make the discharged flue gas meet strict environmental protection standards and reduce the impact on the surrounding ecological environment.

[0041] For the high-temperature flue gas in the reaction layer of the submerged arc furnace body, usually a set of external blower is used in cooperation with a set of flue gas cooling device and flue gas purification device for treatment. For the flue gas near the position of the tapping hole (iron tapping hole), usually an external blower is used in cooperation with a scattered dust removal device for treatment. According to the applicant's research, when building a submerged arc furnace, due to the need to use multiple sets of advanced flue gas treatment equipment, the construction cost of the submerged arc furnace has always been high. And when the submerged arc furnace is working, it is necessary to continuously output cooling air into the furnace. A large amount of nitrogen oxides will be generated by the cooling air in the high-temperature environment. The treatment of nitrogen oxides usually adopts low-nitrogen combustion technology and SNCR technology. The continuously generated large amount of nitrogen oxides undoubtedly increases the flue gas treatment cost during the operation of the submerged arc furnace.

[0042] In view of this, the present utility model proposes a submerged arc furnace circulation system to solve the above technical problems.

[0043] Please refer to Figure 1 , in an embodiment of the present utility model, the submerged arc furnace circulation system 1000 includes a furnace body 1, a main air duct 2, an air seal blower 3, a circulation pipeline 4, and a treatment device 5. Among them, the furnace body 1 includes a reaction layer 11 and a tapping layer 12 provided at the bottom of the reaction layer 11; the main air duct 2 is installed at the top of the reaction layer 11, and one end of the main air duct 2 is communicated with the reaction layer 11; the air seal blower 3 is communicated with the other end of the main air duct 2 and is used for conveying gas into the reaction layer 11; one end of the circulation pipeline 4 is communicated with the tapping layer 12, and the other end is communicated with the air seal blower 3; the treatment device 5 is communicated with the reaction layer 11 and is used for treating flue gas.

[0044] Specifically, the reaction layer 11 in the furnace body 1 is used to reduce ores and generally includes structures such as a molten bath, a furnace cover, electrodes, and a short network of the furnace lining. The reaction temperature during the smelting of ores in the reaction layer 11 can usually reach 2000°C. To avoid damaging the furnace top structures such as the short network, a gas sealing fan 3 is usually used to blow a large amount of low-temperature air into the reaction layer 11 to reduce the temperature. The temperature of the flue gas escaping from the furnace top can be reduced to 800°C - 900°C. Since no reduction reaction occurs in the tapping layer 12, the flue gas at its top is usually low-temperature flue gas with a temperature of about 80°C. The tapping layer 12 and the gas sealing fan 3 are connected through a circulation pipeline 4, so that the low-temperature flue gas in the tapping layer 12 can circulate into the main air duct 2 and enter the reaction layer 11 under the action of the gas sealing fan 3, thereby achieving the effect of reducing the temperature of the reaction layer 11. At this time, due to the continuous entry of the low-temperature flue gas into the reaction layer 11, the demand for air is greatly reduced, thus reducing the consumption of air, and also avoiding the generation of nitrogen oxides by the nitrogen and oxygen in the air under high-temperature action, reducing the generation amount of nitrogen oxides, and thus reducing the cost of flue gas treatment. At the same time, the low-temperature flue gas in the tapping layer 12 contains some nitrogen oxides. Since the reaction layer 11 is in a dynamic equilibrium environment of constant temperature and constant pressure, after injecting the low-temperature flue gas, the concentration of nitrogen oxides will increase, thereby inhibiting the generation of new nitrogen oxides, and further reducing the generation amount of nitrogen oxides. In addition, the submerged arc furnace circulation system 1000 in this embodiment is provided with at least one set of treatment device 5 for treating and purifying flue gas, which is connected to the reaction layer 11 and is arranged close to the furnace top, so that the high-temperature flue gas can be directly purified by the treatment device 5 and then discharged into the atmosphere, reducing the investment in multiple sets of flue gas treatment equipment. In this embodiment, the gas sealing fan 3 is composed of an impeller, a rotating shaft, bearings, a sealing device, a driving device, and a base, and is responsible for extracting and transporting the low-temperature flue gas for recirculation. At the same time, by adjusting the impeller speed of the gas sealing fan 3, the pressure in the reaction layer 11 can be adjusted to maintain the pressure stability in the reaction layer 11.

[0045] It should be noted that in this embodiment, the main air duct 2 is connected to the feeding structure 21. The low-temperature flue gas in the tapping layer 12 passes through the circulation pipeline 4 and enters the main air duct 2 under the drive of the gas sealing fan 3, and then enters the feeding structure 21 and enters the reaction layer 11 through the feeding structure 21. Through this setting, the feeding structure 21 has both the functions of feeding and air supply, which is beneficial to cost saving and reducing the space occupied by the main air duct 2 in the furnace body 1.

[0046] In addition, the low-temperature flue gas recycled by the tapping layer 12 also contains some unreacted raw materials. By injecting the low-temperature flue gas into the reaction layer 11 again, the recycling of these raw materials can be realized, improving the economic benefits of production.

[0047] In the technical solution provided by the present utility model, the submerged arc furnace circulation system 1000 includes a furnace body 1, a main air duct 2, an air sealing fan 3, a circulation pipeline 4 and a treatment device 5. Among them, the furnace body 1 includes a reaction layer 11 and a tapping layer 12 arranged at the bottom of the reaction layer 11; the main air duct 2 is installed at the top of the reaction layer 11, and one end of the main air duct 2 is communicated with the reaction layer 11; the air sealing fan 3 is communicated with the other end of the main air duct 2 for conveying gas into the reaction layer 11; one end of the circulation pipeline 4 is communicated with the tapping layer 12, and the other end is communicated with the air sealing fan 3; the treatment device 5 is communicated with the reaction layer 11 for treating flue gas. Through this setting, the low-temperature flue gas in the tapping layer 12 is further cooled in the circulation pipeline 4 and then conveyed to the reaction layer 11 through the air sealing fan 3 and the main air duct 2, which is used to reduce the temperature of the reaction layer 11, reduce the entry of cooling air, thereby reducing the input of nitrogen and oxygen in the air, and further reducing the generation amount of nitrogen oxides. This setting enables the tapping layer 12 not to be provided with additional flue gas treatment equipment, reduces the equipment investment cost, while reducing the generation amount of nitrogen oxides, reducing the cost of flue gas denitrification, and ultimately reducing the construction and operation costs of the submerged arc furnace.

[0048] Further, in an embodiment of the present utility model, the circulation pipeline 4 includes an intake pipe 41, a delivery pipe 42 and an intake flow control valve 43. One end of the intake pipe 41 is communicated with the tapping layer 12, and the other end is communicated with one end of the delivery pipe 42. The other end of the delivery pipe 42 is communicated with the air sealing fan 3, and the intake flow control valve 43 is arranged on the intake pipe 41. Specifically, please refer to Figure 1 , the intake pipe 41 is used to be directly communicated with the tapping layer 12, so that the low-temperature flue gas in the tapping layer 12 enters the circulation pipeline 4, and then enters the delivery pipe 42 under the action of the air sealing fan 3, and finally enters the main air duct 2 through the air sealing fan 3. An intake flow control valve 43 for opening and closing the intake pipe 41 and adjusting the gas flow is arranged on the intake pipe 41, which is composed of a valve body, a flow channel, a valve core, a sealing structure, a valve seat and a connecting piece, etc. The intake flow control valve 43 can adjust the flow of the low-temperature flue gas passing through the intake pipe 41 as needed. When a large amount of low-temperature flue gas is required in the reaction layer 11, the opening of the flow channel is increased, and vice versa, the opening of the flow channel is reduced. Adjusting the intake flow control valve 43 can also play a role in stabilizing the system pressure.

[0049] Still further, in an embodiment of the present utility model, the circulation pipeline 4 further includes an outlet flow control valve 44, and the outlet flow control valve 44 is arranged at one end of the delivery pipe 42 close to the air sealing fan 3. Please refer to Figure 1, an outlet gas flow control valve 44 is arranged at one end of the gas transmission pipe 42 close to the gas sealing fan 3 for controlling the flow rate of the low-temperature flue gas input into the gas sealing fan 3. The outlet gas flow control valve 44 and the inlet gas flow control valve 43 can be adjusted synchronously to maintain the same gas flow rate, so as to improve the stability of the flow of the low-temperature flue gas in the circulation pipe 4. In addition, by arranging the outlet gas flow control valve 44, when an accident or failure occurs at or near the inlet gas flow control valve 43 and the inlet gas flow control valve 43 cannot be directly operated, the connection between the charging layer 12 and the gas sealing fan 3 can be cut off by closing the outlet gas flow control valve 44, avoiding the operation of the gas sealing fan 3 from affecting the maintenance process at the inlet gas flow control valve 43.

[0050] In an embodiment of the present utility model, the circulation pipe 4 further includes a monitoring assembly 45. The monitoring assembly 45 includes a temperature sensor 451, a pressure sensor 452 and a flow sensor 453. The pressure sensor 452 is arranged at one end of the inlet pipe 41 close to the charging layer 12, and the temperature sensor 451 and the flow sensor 453 are arranged at intervals at one end of the gas transmission pipe 42 close to the gas sealing fan 3. Please refer to Figure 1 , in this embodiment, the monitoring assembly 45 includes a temperature sensor 451, a pressure sensor 452 and a flow sensor 453. According to needs, the number of each type of sensor arranged can be one or more. Among them, the pressure sensor 452 is arranged near the inlet gas flow control valve 43 of the inlet pipe 41, mainly for monitoring the negative pressure of the charging layer 12 and feeding back to the control device. According to the monitoring result of the pressure sensor 452, the control device can adjust the rotation speed of the impeller of the gas sealing fan 3. The temperature sensor 451 and the flow sensor 453 are arranged near the outlet gas flow control valve 44 of the gas transmission pipe 42, and are respectively used for monitoring the input temperature and input flow rate of the low-temperature flue gas and feeding back to the control device. The monitoring assembly 45 is used for real-time monitoring of the parameters of the low-temperature flue gas, providing data support for the control and optimization of the control device.

[0051] In an embodiment of the present utility model, the intake pipe 41 includes an inlet section 411 and a transition section 412. The inlet section 411 includes a pipe outer shell and a refractory layer, and the refractory layer is disposed on the inner wall surface of the pipe outer shell. One end of the inlet section 411 is communicated with the tapping layer 12, the other end is communicated with one end of the transition section 412, and the other end of the transition section 412 is communicated with the gas transmission pipe 42. Since the inlet section 411 is directly communicated with the tapping layer 12, the temperature of the low-temperature flue gas entering the inlet section 411 may be relatively high. Therefore, one or more refractory layers need to be provided in the pipe outer shell of the inlet section 411. The manufacturing material of the refractory layer includes one of refractory castables, expanded perlite, corundum, silica bricks and other materials. The pipe outer shell is made of a metal material, and the pipes at the remaining positions in the circulation pipe 4 also adopt the pipe outer shell in this embodiment to reduce the complexity of manufacturing the circulation pipe 4. By providing the refractory layer, the inlet section 411 is less eroded by the low-temperature flue gas, and the service life of this part is improved. The refractory layer is not provided at the remaining positions of the circulation pipe 4, so that the heat in the low-temperature flue gas is exchanged with the outside atmosphere through the pipe outer shell, thereby reducing the temperature of the low-temperature flue gas to achieve a better cooling effect on the reaction layer 11.

[0052] In an embodiment of the present utility model, the submerged arc furnace circulation system 1000 further includes an air inlet pipe 6. The air sealing fan 3 includes an air inlet and an air outlet. The air inlet pipe 6 is communicated with the air inlet, the main air pipe 2 is communicated with the air outlet, and the circulation pipe 4 is communicated with the air inlet. Please refer to Figure 1 and Figure 2, the air inlet pipe 6 is used for air flow. Under the action of the air sealing fan 3, air enters the main air pipe 2 through the air inlet pipe 6 and finally enters the reaction layer 11, thereby cooling the reaction layer 11. The air inlet of the air sealing fan 3 is connected to both the air inlet pipe 6 and the circulation pipe 4 at the same time, and the air outlet is connected to the main air pipe 2. The air sealing fan 3 extracts low-temperature flue gas and air from the circulation pipe 4 and the air inlet pipe 6 and injects them into the reaction layer 11 through the main air pipe 2 to achieve the purpose of reducing the temperature of the reaction layer 11. It should be noted that there are various connection methods between the air inlet pipe 6 and the circulation pipe 4 and the air sealing fan 3. In this embodiment, the air inlet of the air sealing fan 3 is connected to one opening of the tee pipe. One of the other two openings of the tee pipe is connected to the air inlet pipe 6 to achieve the purpose of connecting the air inlet pipe 6 to the air inlet; the last opening of the tee pipe is connected to the circulation pipe 4. Specifically, this opening is connected to one end of the gas transmission pipe 42 close to the air sealing fan 3 to achieve the purpose of connecting the circulation pipe 4 to the air inlet. Using this connection method, there is no need to open holes in the pipe wall of the air inlet pipe 6 or the rest of the pipeline. Only a tee pipe can achieve the purpose, which is simple and convenient during construction and avoids the situation of flue gas leakage caused by opening holes in the pipe wall. In another embodiment, a connection hole is opened on the pipe wall of the air inlet pipe 6. After the gas transmission pipe 42 is connected to the air inlet pipe 6 through the connection hole, one end of the air inlet pipe 6 is connected to the air inlet of the air sealing fan 3 to achieve the purpose of connecting the circulation pipe 4 and the air inlet pipe 6 to the air inlet.

[0053] Further, in an embodiment of the present invention, the air inlet pipe 6 includes an air flow control valve, and the air flow control valve is arranged at one end of the air inlet pipe 6 close to the air inlet. Specifically, please refer to Figure 1 And Figure 2 , an air flow control valve is arranged at a position of the air inlet pipe 6 close to the air sealing fan 3 for controlling the passing flow of air. In this embodiment, when the submerged arc furnace circulation system 1000 is in use, the opening and closing of the air flow control valve are adjusted according to the temperature in the reaction layer 11. When the temperature in the reaction layer 11 is relatively low, only the intake air flow control valve 43 and the outlet air flow control valve 44 in the circulation pipe 4 are opened, and the air flow control valve is closed, and only the low-temperature flue gas participating in the circulation in the tapping layer 12 is used to cool the reaction layer 11; when the temperature of the reaction layer 11 is relatively high, the air flow control valve is opened to inject air into the reaction layer 11 to control the overall temperature in the reaction layer 11. Through this setting, it is possible to avoid using air to cool the reaction layer 11 to the greatest extent and avoid the difficulty of controlling the temperature of the reaction layer 11 when the temperature of the reaction layer 11 is too high.

[0054] In an embodiment of the present invention, the treatment device 5 includes a main flue 51, an air cooler 52, a flue gas treatment tower and an external fan. The main flue 51 is connected to the reaction layer 11, and the main flue 51, the air cooler 52, the flue gas treatment tower (not shown in the figure) and the external fan (not shown in the figure) are connected in sequence. Please refer toFigure 1 and Figure 3 The main flue 51 in the processing device 5 is used to allow the high-temperature flue gas in the reaction layer 11 to pass through. The low-temperature flue gas in the furnace discharge layer 12 is circulated to the reaction layer 11 again and becomes a part of the high-temperature flue gas. At the same time, after the temperature of the air injected into the reaction layer 11 increases, the by-products of the mixed ore reduction reaction also become a part of the high-temperature flue gas. Driven by an external fan, the high-temperature flue gas passes through the main flue 51 and enters the air cooler 52 for cooling. The air cooler 52 includes a pipe box, heat dissipation fins, a frame and a bent tube bundle to increase the heat dissipation area for cooling the high-temperature flue gas. After the high-temperature flue gas is cooled by the air cooler 52, it enters the flue gas treatment tower. The flue gas treatment tower includes a desulfurization and denitrification tower for removing solid particles, sulfur oxides and nitrogen oxides in the flue gas. The flue gas treated in the flue gas treatment tower and meeting the emission standards is discharged into the atmosphere under the action of the external fan.

[0055] Furthermore, in one embodiment of the present invention, the processing device 5 further includes a waste heat recovery device 53, which is arranged in parallel with the air cooler 52. The main flue 51 includes a main pipe 511, a first branch pipe 512, a second branch pipe 513, a first valve 514, and a second valve 515. One end of the main pipe 511 is connected to the reaction layer 11, and the other end is connected to the first branch pipe 512 and the second branch pipe 513 respectively. The first branch pipe 512 is installed with a first valve 514, and the second branch pipe 513 is installed with a second valve 515. The first branch pipe 512 is connected to the air cooler 52, and the second branch pipe 513 is connected to the waste heat recovery device 53. The air cooler 52 and the waste heat recovery device 53 are both connected to the flue gas treatment tower. For details, please refer to Figure 1 and Figure 3 The waste heat recovery device 53 is arranged in parallel with the air cooler 52. When it is necessary to recover and utilize the heat in the high-temperature flue gas, such as using this heat to cooperate with the steam turbine generator to output electricity, it is only necessary to open the second valve 515. When in use, according to production requirements, choose to open one of the first valve 514 or the second valve 515, or open both valves. In this embodiment, the main pipe 511 is connected to the first branch pipe 512 and the second branch pipe 513 by a three-way pipe. The waste heat recovery device 53 includes a waste heat recovery boiler, which includes a boiler drum, a heating surface, an economizer, a furnace wall and an insulation layer, a flue gas pipeline structure, a steam-water pipeline structure, etc., which is used to recover waste heat, produce steam, and reduce energy consumption and costs. Through this arrangement, the heat resources in the high-temperature flue gas can be reused to improve the economic benefits of production.

[0056] In an embodiment of the present utility model, the main pipe 511 includes a smoke hood 5111 and a flue pipe 5112. The smoke hood 5111 includes a gas collection port and an exhaust port. The gas collection port and the exhaust port are oppositely arranged, and the outer contours of both the gas collection port and the exhaust port are circular. The diameter of the outer contour of the gas collection port is greater than that of the outer contour of the exhaust port. The gas collection port is communicated with the reaction layer 11, and the exhaust port is communicated with the flue pipe 5112. The flue pipe 5112 is respectively communicated with the first branch pipe 512 and the second branch pipe 513. Please refer to Figure 1 , the gas collection port of the smoke hood 5111 is used to cover the connection part between the top of the reaction layer 11 furnace and the main flue 51, so as to increase the collection area of high-temperature flue gas and enable the high-temperature flue gas to flow into the flue pipe 5112 more smoothly.

[0057] In an embodiment of the present utility model, the submerged arc furnace circulation system 1000 further includes a sealing gasket. The sealing gasket is arranged between the connection parts of each device, the circulation pipeline 4 and the main flue 51 of the submerged arc furnace circulation system 1000. The manufacturing material thereof includes one of carbonaceous refractory material, magnesia refractory material, high-alumina refractory material, and copper refractory material. The sealing gasket is used to prevent the flue gas from leaking to the surrounding environment, thereby avoiding pollution to the surrounding environment.

[0058] The above is only an exemplary embodiment of the present utility model, and does not limit the patent scope of the present utility model. Any equivalent structural transformation made under the technical concept of the present utility model by using the content of the specification and drawings of the present utility model, or directly / indirectly applied in other related technical fields, is included in the patent protection scope of the present utility model.

Claims

1. A submerged arc furnace circulation system, characterized in that, Comprising: A furnace body, which includes a reaction layer and a tapping layer arranged at the bottom of the reaction layer; A main air duct, which is installed at the top of the reaction layer, and one end of the main air duct is communicated with the reaction layer; An air seal fan, which is communicated with the other end of the main air duct, and the air seal fan is used to convey gas into the reaction layer through the main air duct; A circulation pipeline, one end of which is communicated with the tapping layer and the other end is communicated with the air seal fan; A treatment device, which is communicated with the reaction layer and is used to treat flue gas.

2. The submerged arc furnace circulation system according to claim 1, wherein, The circulation pipeline includes an intake pipe, a gas transmission pipe and an intake flow control valve. One end of the intake pipe is communicated with the tapping layer, the other end is communicated with one end of the gas transmission pipe, the other end of the gas transmission pipe is communicated with the air seal fan, and the intake flow control valve is arranged on the intake pipe.

3. The submerged arc furnace circulation system according to claim 2, characterized in that, The circulation pipeline further includes an outlet flow control valve, which is arranged at one end of the gas transmission pipe close to the air seal fan.

4. The submerged arc furnace circulation system according to claim 2, wherein The circulation pipeline further includes a monitoring component, which includes a temperature sensor, a pressure sensor and a flow sensor. The pressure sensor is arranged at one end of the intake pipe close to the tapping layer, and the temperature sensor and the flow sensor are arranged at intervals at one end of the gas transmission pipe close to the air seal fan.

5. The submerged arc furnace circulation system according to claim 2, wherein The intake pipe includes an inlet section and a transition section. The inlet section includes a pipe outer shell and a refractory layer, and the refractory layer is arranged on the inner wall surface of the pipe outer shell; One end of the inlet section is communicated with the tapping layer, and the other end is communicated with one end of the transition section, and the other end of the transition section is communicated with the gas transmission pipe.

6. The submerged arc furnace circulation system according to claim 1, wherein The submerged arc furnace circulation system further includes an air inlet pipe. The air seal fan includes an air inlet and an air outlet. The air inlet pipe is communicated with the air inlet, the main air duct is communicated with the air outlet, and the circulation pipeline is communicated with the air inlet.

7. The submerged arc furnace circulation system according to claim 6, wherein, The air inlet pipe includes an air flow control valve, which is arranged at one end of the air inlet pipe close to the air inlet.

8. The submerged arc furnace circulation system according to claim 1, characterized in that, The treatment device includes a main flue, an air cooler, a flue gas treatment tower and an external fan. The main flue is communicated with the reaction layer, and the main flue, the air cooler, the flue gas treatment tower and the external fan are communicated in sequence.

9. The submerged arc furnace circulation system according to claim 8, wherein The treatment device further includes a waste heat recovery device, which is arranged in parallel with the air cooler. The main flue includes a main pipe, a first branch pipe, a second branch pipe, a first valve and a second valve. One end of the main pipe is communicated with the reaction layer, and the other end is respectively communicated with the first branch pipe and the second branch pipe. The first valve is installed on the first branch pipe, the second valve is installed on the second branch pipe, the first branch pipe is communicated with the air cooler, the second branch pipe is communicated with the waste heat recovery device, and both the air cooler and the waste heat recovery device are communicated with the flue gas treatment tower.

10. The submerged arc furnace circulation system according to claim 9, characterized in that, The main pipe includes a smoke hood and a flue pipe. The smoke hood includes a gas collection port and an exhaust port. The gas collection port and the exhaust port are oppositely arranged, and the outer contours of both the gas collection port and the exhaust port are circular. The diameter of the outer contour of the gas collection port is larger than that of the outer contour of the exhaust port. The gas collection port is communicated with the reaction layer, the exhaust port is communicated with the flue pipe, and the flue pipe is respectively communicated with the first branch pipe and the second branch pipe.

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