Oxyfuel smelting furnace

Abstract

The application discloses a full-oxygen combustion smelting furnace, which comprises a shell, an inner cavity formed in the shell, a crucible arranged in the inner cavity and used for containing materials to be smelted, and a plurality of full-oxygen combustion devices arranged on the shell in at least two layers in the vertical direction. Each full-oxygen combustion device comprises at least one oxygen lance and at least one fuel gas lance, the inlets of the oxygen lance and the fuel gas lance are respectively located outside the shell, the extension directions of the oxygen flow channels in the oxygen lance and the fuel gas flow channels in the fuel gas lance are respectively tangent to the inner wall of the inner cavity, and the outlets of the oxygen lance and the fuel gas lance are communicated with the inner cavity. The application solves the technical problems of large volume, low thermal efficiency, high energy consumption and uneven heating of the regenerative smelting furnace.

Description

Technical Field

[0001] This invention relates to the field of metal smelting technology, and more particularly to an oxy-fuel combustion smelting furnace, especially an oxy-fuel combustion smelting furnace for smelting magnesium alloys. Background Technology

[0002] Magnesium and magnesium alloys are widely used in the automotive, aerospace, military equipment, and medical fields due to their high specific strength, high specific modulus, high damping, good vibration reduction, good electromagnetic shielding, excellent casting and machining properties, and easy recycling. They are also the metal with the strongest known hydrogen storage capacity, reaching 7.6%, and have broad application prospects. In traditional methods, over 98% of primary magnesium production uses the silicothermic process (which is further divided into the Pidgeon, Bolzano, and Magnethem processes; the Pidgeon process is a mainstream method). Crystalline magnesium produced by the Pidgeon process has a high impurity content, is highly corrosive, has a loose structure, and is difficult to store and transport. Therefore, crystalline magnesium must be refined to remove impurities and cast into ingots to meet industrial requirements. The quality of the magnesium refining process directly affects the quality of the finished magnesium product and the overall indicators of magnesium production.

[0003] Currently, most magnesium plants use coal-fired crucible furnaces for magnesium refining, which suffers from problems such as low thermal efficiency, uneven furnace temperature, low quality of finished magnesium, easy crucible burnout, and significant energy waste. Conventional gas combustion also has high energy consumption. While regenerative gas combustion methods have reduced energy consumption in recent years, they have brought new problems such as large burner size, increased furnace floor space, excessively high operating temperatures, and high investment, operation, and maintenance costs. The specific structure of existing regenerative magnesium alloy smelting furnaces is as follows: Figure 1 As shown:

[0004] A crucible 400 is placed inside an outer shell 100, and an exhaust hood 800 is installed on top of the crucible 400. Between the outer shell 100 and the crucible 400, from the inside out, a refractory brick layer 300, an insulating brick layer 200, a casting layer 600, and an insulating surface layer 500 are arranged sequentially. A regenerative burner 700 is installed on the outer shell 100, passing through the insulating surface layer 500, the casting layer 600, the insulating brick layer 200, and the refractory brick layer 300 and connecting to the crucible 400. Magnesium alloy to be melted is placed inside the crucible 400. Air is introduced into the crucible 400 through the exhaust hood 800, and fuel gas is introduced into the crucible 400 through the regenerative burner 700. After ignition, the magnesium alloy is melted inside the crucible 400. However, the disadvantage of this method is:

[0005] 1) The 700 regenerable burner is large in size, making it difficult to arrange two adjacent furnaces in a limited furnace area. This can result in a large footprint for the entire furnace group in the workshop, a large initial investment, and high operating costs due to damage to the regenerable body during long-term operation.

[0006] 2) Due to the use of regenerative burners 700 (large volume), each smelting furnace can only be equipped with a small number of burners (generally 1 to 2 pairs of regenerative burners 700), resulting in uneven distribution of combustion flame temperature in the furnace, which leads to uneven distribution of heat flux density on the surface of crucible 400, which is not conducive to uniform heating, affects the quality of smelted products, and also affects the lifespan of crucible 400.

[0007] 3) Due to the high surface temperature of the regenerative burner 700, regenerative combustion is prone to causing excessively high furnace temperatures and a harsh operating environment.

[0008] 4) The refractory brick layer 300 and the regenerable burner 700 in the outer shell 100 are made of heavy materials such as refractory brick casting material, which results in a large heat storage capacity of the furnace body, slow heating and cooling rate, large thermal inertia, low efficiency and high energy consumption.

[0009] There is currently no effective solution to the problems of large size, low thermal efficiency, high energy consumption and uneven heating in regenerative melting furnaces in related technologies.

[0010] Therefore, based on years of experience and practice in related industries, the inventor proposes an all-oxygen combustion smelting furnace to overcome the shortcomings of existing technologies. Summary of the Invention

[0011] The purpose of this invention is to provide an all-oxygen combustion smelting furnace that effectively improves the thermal efficiency of combustion, increases the efficiency of radiative heat transfer inside the furnace, and achieves energy saving, carbon reduction, and reduction of nitrogen oxide emissions. At the same time, the furnace body is miniaturized, occupies a small area, and improves the operating environment.

[0012] The objective of this invention can be achieved through the following methods:

[0013] This invention provides an all-oxygen combustion smelting furnace, the all-oxygen combustion smelting furnace comprising:

[0014] An outer casing, wherein an inner cavity is formed within the outer casing;

[0015] A crucible, which is disposed in the inner cavity, and is used to hold the material to be melted;

[0016] Multiple oxygen-fueled combustion devices are arranged vertically in at least two layers on the outer casing;

[0017] Each of the aforementioned oxy-fuel combustion devices includes at least one oxygen nozzle and at least one gas nozzle. The inlet of the oxygen nozzle and the inlet of the gas nozzle are respectively located outside the housing. The extension direction of the oxygen flow channel inside the oxygen nozzle and the extension direction of the gas flow channel inside the gas nozzle are respectively tangent to the inner wall of the inner cavity, and the outlet of the oxygen nozzle and the outlet of the gas nozzle are in communication with the inner cavity.

[0018] In a preferred embodiment of the present invention, the oxygen delivered by the oxygen spray gun and the gas delivered by the gas spray gun both enter the inner cavity in a direction tangential to the inner wall of the inner cavity. In the flow direction of oxygen and gas in the inner cavity, the flue gas generated by the upstream all-oxygen combustion device in the same layer is used to dilute the oxygen and gas input into the inner cavity by the downstream all-oxygen combustion device to form a high-temperature and low-oxygen region.

[0019] In a preferred embodiment of the present invention, the oxygen spray gun is provided with a first cooling port, which is connected to the oxygen flow channel;

[0020] And / or, the gas spray gun is provided with a second cooling port, which is connected to the gas flow channel.

[0021] In a preferred embodiment of the invention, in the vertical direction, the plurality of the oxygen-fueled combustion devices in two adjacent layers are staggered in the vertical direction.

[0022] In a preferred embodiment of the present invention, the oxygen nozzle and the gas nozzle in each of the all-oxygen combustion devices are an integral structure.

[0023] In a preferred embodiment of the present invention, the oxygen nozzle and the gas nozzle in each of the oxygen combustion devices are separate structures, and multiple oxygen nozzles and multiple gas nozzles in the same layer are arranged alternately.

[0024] In a preferred embodiment of the present invention, a plurality of the oxygen-fueled combustion devices in the same layer are spaced apart and evenly arranged along the circumferential direction of the outer casing.

[0025] In a preferred embodiment of the present invention, the outer casing is provided with a plurality of exhaust pipes, the inlets of the plurality of exhaust pipes are all connected to the inner cavity, the plurality of exhaust pipes pass through the outer casing and the outlets of the plurality of exhaust pipes are connected to the outside.

[0026] In a preferred embodiment of the present invention, the height of the exhaust duct is greater than the height of the oxygen-fueled combustion device.

[0027] In a preferred embodiment of the present invention, the operating states of the plurality of oxygen-fueled combustion devices located on different layers are controlled by timing pulses.

[0028] In a preferred embodiment of the present invention, the oxygen-fuel combustion device in the same layer is subjected to timing pulse control, or the oxygen and fuel gas supplied by the oxygen-fuel combustion device in the same layer are subjected to proportional control.

[0029] In a preferred embodiment of the present invention, a heat-insulating bushing layer is provided on the inner wall of the outer shell, and a high-temperature resistant heat-insulating coating is provided on the inner side of the bushing layer.

[0030] The bushing layer is made of high-temperature refractory fiber.

[0031] In a preferred embodiment of the present invention, the oxygen flow rate in the oxygen spray gun is greater than 100 m / s, and the gas flow rate in the gas spray gun is greater than 100 m / s.

[0032] In a preferred embodiment of the present invention, the circulation rate of the flue gas generated by the all-oxygen combustion device in the inner cavity is greater than 2.5.

[0033] As described above, the features and advantages of the all-oxygen combustion smelting furnace of the present invention are as follows: multiple all-oxygen combustion devices are arranged in at least two layers on the outer shell. Each all-oxygen combustion device includes at least one oxygen nozzle and at least one gas nozzle. The extension direction of the oxygen flow channel in the oxygen nozzle and the extension direction of the gas flow channel in the gas nozzle are tangent to the inner wall of the inner cavity, so that the oxygen delivered by the oxygen nozzle and the gas delivered by the gas nozzle both enter the inner cavity in a direction tangent to the inner wall of the inner cavity. This achieves circumferential, high-speed, and circulating mixing of oxygen, gas, and high-temperature flue gas generated after combustion in the inner cavity. Due to the circumferential circulation of oxygen and gas in the inner cavity, the high-temperature flue gas generated by the upstream all-oxygen combustion device can be used to dilute and heat the oxygen and gas input into the inner cavity by the downstream all-oxygen combustion device. This creates a high-temperature, low-oxygen zone in the inner cavity, ensuring flameless combustion of gas and oxygen in the inner cavity. This makes the temperature field distribution in the inner cavity more uniform, significantly improving the temperature uniformity of the smelting crucible and the uniformity of the heat flux density distribution on the wall, and increasing the service life of the smelting crucible. Attached Figure Description

[0034] The accompanying drawings are intended only to illustrate and explain the present invention and do not limit the scope of the invention.

[0035] in:

[0036] Figure 1 : This is a schematic diagram of the structure of a regenerative magnesium alloy melting furnace in the prior art.

[0037] Figure 2 : This is a front cross-sectional view of the all-oxygen combustion smelting furnace of the present invention.

[0038] Figure 3 : This is one of the top cross-sectional views of the all-oxygen combustion smelting furnace of the present invention.

[0039] Figure 4 : This is the second top cross-sectional view of the all-oxygen combustion smelting furnace of the present invention.

[0040] Figure 5 This is the third top cross-sectional view of the all-oxygen combustion smelting furnace of the present invention.

[0041] Figure 6 This is the fourth top cross-sectional view of the all-oxygen combustion smelting furnace of the present invention.

[0042] Figure 7 This is the fifth top cross-sectional view of the all-oxygen combustion smelting furnace of the present invention.

[0043] Figure 8 This is the sixth top cross-sectional view of the all-oxygen combustion smelting furnace of the present invention.

[0044] The reference numerals in the background art are:

[0045] 100. Outer shell; 200. Insulating brick layer; 300. Refractory brick layer; 400. Crucible; 500. Insulating cotton layer; 600. Casting layer; 700. Regenerator burner; 800. Exhaust fan hood.

[0046] The reference numerals in the accompanying drawings of this invention are:

[0047] 1. Outer shell; 101. Inner cavity; 102. Exhaust pipe; 2. Crucible; 3. Oxygen combustion device; 301. Oxygen lance; 3011. First cooling port; 302. Gas lance; 3021. Second cooling port; 4. Bushing layer; 5. Thermal insulation coating. Detailed Implementation

[0048] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0049] like Figures 2 to 8As shown, the present invention provides an oxy-fuel combustion smelting furnace, which includes an outer shell 1, a crucible 2, and multiple oxy-fuel combustion devices 3. An inner cavity 101 is formed within the outer shell 1, and the crucible 2 is disposed within the inner cavity 101, containing the material to be smelted. Vertically (i.e., along the height of the outer shell 1), the multiple oxy-fuel combustion devices 3 are arranged in at least two layers on the outer shell 1. Each oxy-fuel combustion device 3 includes at least one oxygen lance 301 and at least one gas lance 302. The inlet of the oxygen lance 301 and the inlet of the gas lance 302 are located outside the outer shell 1, respectively. The inlet of the oxygen lance 301 is connected to an oxygen supply device, and the inlet of the gas lance 302 is connected to a gas supply device. The equipment is connected to the oxygen spray gun 301, which has an oxygen flow channel connecting the inlet and outlet of the oxygen spray gun 301. The gas spray gun 302 has a gas flow channel connecting the inlet and outlet of the gas spray gun 302. The extension directions of the oxygen flow channel in the oxygen spray gun 301 and the gas flow channel in the gas spray gun 302 are tangential to the inner wall of the inner cavity 101, and the outlets of the oxygen spray gun 301 and the gas spray gun 302 are connected to the inner cavity 101. Thus, oxygen is output tangentially along the inner wall of the inner cavity 101 through the outlet of the oxygen spray gun 301, and gas is output tangentially along the inner wall of the inner cavity 101 through the outlet of the gas spray gun 302.

[0050] In this invention, the multiple oxygen-fuel combustion devices 3 on the outer shell 1 are arranged in at least two layers. Each oxygen-fuel combustion device 3 includes at least one oxygen nozzle 301 and at least one gas nozzle 302. The extension direction of the oxygen flow channel in the oxygen nozzle 301 and the extension direction of the gas flow channel in the gas nozzle 302 are tangent to the inner wall of the inner cavity 101, so that the oxygen delivered by the oxygen nozzle 301 and the gas delivered by the gas nozzle 302 both enter the inner cavity 101 in a direction tangent to the inner wall of the inner cavity 101, thereby realizing the circulation of oxygen, gas, and high-temperature flue gas generated after combustion in the inner cavity 101. The circumferential, high-speed, and circulating mixing of oxygen and fuel gas within the inner cavity 101 allows the high-temperature flue gas generated by the upstream oxy-fuel combustion device 3 to dilute and heat the oxygen and fuel gas input into the inner cavity 101 from the downstream oxy-fuel combustion device 3. This creates a high-temperature, low-oxygen zone within the inner cavity 101, ensuring flameless combustion of the fuel gas and oxygen. This results in a more uniform temperature field distribution within the inner cavity 101, significantly improving the temperature uniformity of the crucible 2 and the uniformity of the heat flux density distribution on the crucible 2 wall, thereby extending the service life of the crucible 2.

[0051] In this invention, multiple oxy-fuel combustion devices 3 are arranged in at least two layers on the outer shell 1. Of course, a reasonable layout of three or more layers can be arranged according to factors such as the output, volume, and height of a single smelting furnace. In addition, the number of oxy-fuel combustion devices 3 in each layer is at least two. Multiple oxy-fuel combustion devices 3 in the same layer are spaced apart and evenly arranged along the circumference of the outer shell 1. The specific number of oxy-fuel combustion devices 3 in the same layer can be adjusted according to the actual heating needs. The more oxy-fuel combustion devices 3 are arranged in the same layer, the better the heating effect and the more uniform the temperature field distribution.

[0052] In this invention, the material contained in the crucible 2 may be, but is not limited to, magnesium alloy to be melted.

[0053] In this invention, the gas can be, but is not limited to, natural gas, mixed coal gas, coke oven gas, or a mixture of the above gases.

[0054] In this invention, since the oxygen supplied by the oxygen torch 301 and the gas supplied by the gas torch 302 both enter the inner cavity 101 in a direction tangential to the inner wall of the inner cavity 101, the high-temperature flue gas generated by the oxygen and gas of the upstream all-oxygen combustion device 3 in the same layer after combustion can be used to dilute the oxygen and gas input into the inner cavity 101 by the downstream all-oxygen combustion device 3 to form a high-temperature and low-oxygen region. Furthermore, since the oxygen and gas mix and circulate and burn in the circumferential direction of the inner cavity 101, the entire inner cavity 101 achieves flameless all-oxygen combustion, making the entire interior of the inner cavity 101 a uniformly heated combustion temperature field. This not only improves smelting efficiency but also reduces nitrogen oxide emissions, achieving multiple effects such as energy saving, carbon reduction, and pollution reduction.

[0055] In an optional embodiment of the present invention, such as Figures 6 to 8 As shown, at least one first cooling port 3011 is provided on the oxygen nozzle 301 near its inlet. The first cooling port 3011 is connected to the oxygen flow channel. When the oxygen supply is stopped, a cooling medium can be supplied to the oxygen nozzle 301 through the first cooling port 3011 to cool the oxygen nozzle 301. And / or, at least one second cooling port 3021 is provided on the gas nozzle 302 near its inlet. The second cooling port 3021 is connected to the gas flow channel. When the gas supply is stopped, a cooling medium can be supplied to the gas nozzle 302 through the second cooling port 3021 to cool the gas nozzle 302. The cooling medium may be, but is not limited to, cryogenic nitrogen.

[0056] In an optional embodiment of the present invention, such as Figures 2 to 8As shown, in the vertical direction, multiple oxygen-fuel combustion devices 3 in adjacent layers are staggered vertically to ensure that the oxygen and fuel gas entering the inner cavity 101 can be evenly distributed within the inner cavity 101. This ensures a more uniform temperature field distribution within the inner cavity 101, significantly improving the temperature uniformity of the crucible 2 and the uniformity of the heat flux density distribution on the crucible 2 wall. Furthermore, because the multiple oxygen-fuel combustion devices 3 in adjacent layers are staggered vertically, the oxygen and fuel gas can be evenly distributed within the inner cavity 101 from the initial state of entry, laying the foundation for the temperature field distribution within the inner cavity 101 in the initial state.

[0057] In an optional embodiment of the present invention, such as Figures 3 to 5 As shown, the oxygen lance 301 and gas lance 302 in each oxygen-fuel combustion device 3 can be an integrated structure (i.e., the oxygen lance 301 and gas lance 302 are mounted on the same installation structure). Different numbers of oxygen-fuel combustion devices 3 can be installed on each floor according to heating needs, with multiple oxygen-fuel combustion devices 3 evenly and spaced along the circumference of the inner cavity 101. Oxygen is tangentially transported at high speed through the oxygen lance 301 and gas through the gas lance 302 into the annular inner cavity 101. The oxygen and gas, along with the high-temperature flue gas generated by combustion in the inner cavity 101, are entrained by the high-speed jet and circumferentially ...

[0058] In another alternative embodiment of the invention, such as Figures 6 to 8 As shown, the oxygen lance 301 and gas lance 302 in each oxygen combustion device 3 can be of a split structure (i.e., split into separately installed oxygen lance 301 and gas lance 302), with multiple oxygen lances 301 and multiple gas lances 302 arranged alternately in the same layer. Compared with the integrated structure of oxygen lances 301 and gas lance 302, this arrangement of oxygen lances 301 and gas lance 302 can make the distribution of oxygen, gas, and high-temperature flue gas in the inner cavity 101 more uniform, minimize nitrogen oxide emissions, improve furnace temperature uniformity, improve the temperature difference and heat flux density distribution of the crucible 2, and improve smelting quality.

[0059] In an optional embodiment of the present invention, such as Figure 2As shown, multiple exhaust pipes 102 are provided on the outer shell 1. The inlets of the multiple exhaust pipes 102 are all connected to the inner cavity 101, and the outlets of the multiple exhaust pipes 102 are all connected to the outside. The height of the exhaust pipes 102 is greater than the height of the oxy-fuel combustion device 3. After combustion, some of the high-temperature flue gas in the inner cavity 101 can be discharged through the exhaust pipes 102. The remaining high-temperature flue gas in the inner cavity 101 is sufficient to fully dilute the oxygen and fuel gas to ensure the uniformity of the temperature field in the inner cavity 101.

[0060] In an optional embodiment of the present invention, such as Figures 3 to 8 As shown, a heat-insulating bushing layer 4 is provided on the inner wall of the outer shell 1, and a high-temperature resistant heat-insulating coating 5 is provided on the inner side of the bushing layer 4. Through the cooperation of the bushing layer 4 and the heat-insulating coating 5, the refractory material in the melting furnace can be made lighter, reducing the thermal inertia of the furnace body, increasing the heating and cooling rates during the material melting process, and improving the sensitivity and accuracy of temperature control. The bushing layer 4 can be made of, but is not limited to, high-temperature refractory fibers. The heat-insulating coating 5 can be any existing coating with high-temperature resistance; the specific material of the heat-insulating coating 5 is not limited here.

[0061] In an optional embodiment of the present invention, the oxygen flow rate in the oxygen injector 301 is greater than 100 m / s, the gas flow rate in the gas injector 302 is greater than 100 m / s, and the circulation rate Kv of the flue gas generated by the all-oxygen combustion device 3 in the inner cavity 101 is greater than 2.5. This ensures that oxygen, gas, and high-temperature flue gas can achieve circumferential, high-speed, and circulating mixing in the inner cavity 101, thereby ensuring flameless all-oxygen combustion with a uniform temperature field distribution in the inner cavity 101.

[0062] The working process of the all-oxygen combustion smelting furnace of the present invention is as follows: In actual operation, the oxygen delivered by the oxygen nozzle 301 and the gas delivered by the gas nozzle 302 in each all-oxygen combustion device 3 enter the inner cavity 101 tangentially. After being fully mixed and diluted with the high-temperature flue gas in the annular inner cavity 101, flameless all-oxygen combustion is carried out. A part of the high-temperature flue gas continues to circulate in the inner cavity 101, and another part of the high-temperature flue gas is discharged through the exhaust pipe 102. The uniform temperature field generated in the inner cavity 101 transfers the heat energy to the interior through the wall of the crucible 2, thereby smelting the material (magnesium alloy).

[0063] In controlling the formation of a temperature field within the inner cavity 101 by multiple oxy-fuel combustion devices 3, this invention allows for time-pulse control of the operating states of these devices located on different layers according to actual heating requirements. This time-pulse control allows for the operation of more oxy-fuel combustion devices 3 during the heating process and a reduction in the number of devices operating during the heat preservation process. This adapts to the higher power requirements of the smelting furnace during heating and lower power requirements during heat preservation, thus contributing to energy savings.

[0064] In addition, according to actual heating needs, the oxygen combustion devices 3 in the same layer can be controlled by timing pulses (e.g., synchronous control of any two oxygen combustion devices 3 in the same layer), or the oxygen and fuel gas supplied by the oxygen combustion devices 3 in the same layer can be controlled proportionally, so as to achieve targeted control at different stages, so as to meet the needs of the smelting furnace to have a larger power requirement in the heating state and a smaller power requirement in the heat preservation state.

[0065] In an optional embodiment of the present invention, an oxygen-enriched burner with partial air combustion can be used instead of the full oxygen combustion device 3 to form a uniform temperature field in the inner cavity 101.

[0066] The features and advantages of the all-oxygen combustion smelting furnace of the present invention are as follows:

[0067] First, the flameless full oxygen combustion that can be achieved in this all-oxygen combustion smelting furnace results in a more uniform temperature field. Compared with traditional coal combustion, conventional air combustion, or regenerative combustion smelting methods, the thermal efficiency of this invention is higher. The radiative heat transfer efficiency in the inner cavity 101 is improved, and some flue gas participates in dilution circulation, thereby reducing the amount of flue gas emitted and achieving energy saving and carbon reduction effects.

[0068] Second, under flameless full oxygen conditions, the temperature field in the inner cavity 101 of this all-oxygen combustion smelting furnace is more uniform, with no conventional high-temperature flame combustion zone, thus avoiding excessive temperature differences between different areas and consequently avoiding excessive temperature differences on the wall of crucible 2. This achieves a more uniform heat flux density distribution, ensuring uniform heating of the material in crucible 2, while avoiding damage to crucible 2 due to local high temperatures, and ensuring long-term stable operation.

[0069] Third, in this all-oxygen combustion smelting furnace, the uniformity of the temperature field in the inner cavity 101 can be greatly improved by the arrangement of oxygen lances 301 and gas lances 302 and the incident direction of oxygen and gas, and thermal nitrogen oxides can be significantly reduced, thus achieving ultra-low nitrogen oxide emissions.

[0070] Fourth, this all-oxygen combustion smelting furnace can achieve a miniaturized design, reduce the floor space, reduce the difficulty of arranging smelting furnaces in the workshop, and at the same time avoid excessive surface temperature of the outer shell 1, reduce heat dissipation, and improve the harsh high-temperature operating environment of traditional smelting furnaces.

[0071] Fifth, in this all-oxygen combustion smelting furnace, the combination of the lining layer 4 and the heat insulation coating 5 can achieve the lightweighting of refractory materials in the smelting furnace, reduce the thermal inertia of the furnace body, increase the heating and cooling rate during the material smelting process, and improve the temperature control sensitivity and accuracy.

[0072] The above description is merely an illustrative embodiment of the present invention and is not intended to limit the scope of the invention. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principles of the present invention should fall within the scope of protection of the present invention.

Claims

1. An oxygen-fired smelting furnace, characterized by The full-oxygen combustion smelting furnace comprises: a shell, an inner cavity is formed in the shell; a crucible, which is arranged in the inner cavity and used for containing materials to be smelted; a plurality of full-oxygen combustion devices, which are arranged on the shell in vertical direction and divided into at least two layers; each of the full-oxygen combustion devices comprises at least one oxygen lance and at least one fuel gas lance, the inlet of the oxygen lance and the inlet of the fuel gas lance are located outside the shell respectively, the extension direction of the oxygen flow channel in the oxygen lance and the extension direction of the fuel gas flow channel in the fuel gas lance are tangent to the inner wall of the inner cavity respectively, and the outlet of the oxygen lance and the outlet of the fuel gas lance are communicated with the inner cavity; the oxygen delivered by the oxygen lance and the fuel gas delivered by the fuel gas lance both enter the inner cavity in a direction tangent to the inner wall of the inner cavity, in the flow direction of the oxygen and the fuel gas in the inner cavity, the flue gas generated by the full-oxygen combustion device located upstream in the same layer is used to dilute the oxygen and the fuel gas input into the inner cavity by the full-oxygen combustion device located downstream, so as to form a high-temperature low-oxygen area, the oxygen and the fuel gas are mixed and circulated in the circumferential direction of the inner cavity and combusted, so that the whole inner cavity realizes flameless full-oxygen combustion and the whole inner part of the inner cavity is in a uniform heating combustion temperature field.

2. The pure-oxygen combustion smelting furnace of claim 1, wherein, a first cooling port is arranged on the oxygen lance and communicated with the oxygen flow channel; and / or, a second cooling port is arranged on the fuel gas lance and communicated with the fuel gas flow channel.

3. The oxygen-fired smelting furnace of any one of claims 1 to 2, wherein, in vertical direction, the full-oxygen combustion devices in adjacent two layers are staggered in vertical direction.

4. The pure-oxygen combustion smelting furnace of claim 3, wherein, the oxygen lance and the fuel gas lance in each of the full-oxygen combustion devices are of integrated structure.

5. The pure-oxygen combustion smelting furnace of claim 3, wherein, the oxygen lance and the fuel gas lance in each of the full-oxygen combustion devices are of split structure, the oxygen lances and the fuel gas lances in the same layer are arranged alternately.

6. The pure-oxygen combustion smelting furnace of claim 3, wherein the full-oxygen combustion devices in the same layer are spaced and uniformly arranged along the circumference of the shell.

7. The pure-oxygen combustion smelting furnace of claim 1, wherein, a plurality of flue gas discharge pipes are arranged on the shell, the inlets of the flue gas discharge pipes are all communicated with the inner cavity, the flue gas discharge pipes all pass through the shell and the outlets of the flue gas discharge pipes are communicated with the outside.

8. The pure-oxygen combustion smelting furnace of claim 7, wherein, the height of the flue gas discharge pipe is greater than the height of the full-oxygen combustion device.

9. The pure-oxygen combustion smelting furnace of claim 1, wherein, the working states of the full-oxygen combustion devices in different layers are controlled by time sequence pulse.

10. The oxycombustion melting furnace of claim 1 or 9, wherein, the full-oxygen combustion devices in the same layer are controlled by time sequence pulse, or the oxygen and the fuel gas delivered by the full-oxygen combustion devices in the same layer are controlled by proportion.

11. The pure-oxygen combustion smelting furnace of claim 1, wherein, a lining layer for heat preservation is arranged on the inner wall of the shell, a high-temperature resistant heat preservation coating is arranged on the inner side of the lining layer; the lining layer is made of high-temperature resistant fiber.

12. The pure-oxygen combustion smelting furnace of claim 1, wherein, the flow velocity of the oxygen in the oxygen lance is greater than 100 m / s, and the flow velocity of the fuel gas in the fuel gas lance is greater than 100 m / s.

13. The pure-oxygen combustion smelting furnace of claim 1, wherein, the circulation rate of the flue gas generated by the full-oxygen combustion device in the inner cavity is greater than 2.5.

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