Electric furnace annular hole bundling powder spraying oxygen lance

Abstract

The invention belongs to the field of ferrous metallurgy equipment, and relates to an electric furnace annular hole bundling powder spraying oxygen lance. The multi-layer sleeve spray gun which is formed by connecting and combining a water cooling assembly, a cluster spray pipe assembly and a carbon powder spray pipe assembly into a whole through sealing flanges and bolts has the functions of thermal protection, cluster oxygen injection, long-distance powder injection, combustion heating and the like. Powder of the cluster powder spraying oxygen lance flows out from the interior of supersonic jet flow, and carbon powder sprayed out at the position away from the molten pool liquid level is wrapped by the jet flow and directly fed into molten steel of a molten pool. The powder spraying pipe adopts the wear-resistant ceramic pipe, the powder leakage protection pipe and the powder leakage warning pipe are arranged outside the ceramic pipe, and the gap is reserved between the ceramic pipe and the protection pipe, so that smoke alarm can be given out once the ceramic pipe is worn by carbon powder to penetrate through the powder leakage warning pipe, equipment maintenance personnel can conveniently replace the powder leakage warning pipe in time, the harm of accidental production halt is eliminated, and the service life of the oxygen lance is prolonged.

Description

Technical Field

[0001] The invention belongs to the field of iron and steel metallurgical equipment and relates to an electric furnace annular hole clustered powder spraying oxygen gun. Background Art

[0002] An electric furnace is a metallurgical equipment that uses arc heat to heat and melt scrap steel. In order to reduce power consumption, other chemical energy is often required, such as blowing oxygen, carbon powder, fuel gas, etc. during the smelting process. The equipment that implements this type of process is generally called an oxygen gun, a carbon gun, a burner, or a carbon oxygen gun. The carbon powder gun for an electric arc furnace generally uses an ordinary seamless pipe or a whole ceramic pipe as the center pipe, and is replaced after the seamless pipe is worn or the center pipe head is burned. If the replacement is not timely, the inner layer of the carbon gun will be worn or the front copper head will be worn, causing the carbon gun to leak, which is prone to thermal shutdown or production accidents.

[0003] After the 21st century, supersonic beam jet technology represented by Praxair's Cojet technology has been widely used in the gas supply system of electric arc furnace steelmaking. The beam jet is to inject the accompanying gas outside the supersonic jet of the circular hole Laval nozzle, squeeze and isolate and accelerate the oxygen flow beam through the external combustion flame, so that the effective range reaches 80 times the diameter of the Laval nozzle.

[0004] It has always been the dream of metallurgical workers to integrate the carbon powder gun into the center of the cluster oxygen gun, because it can significantly extend the spray distance of the spray. However, due to the high speed of carbon powder spraying, the wear of the spray pipe is also very serious. The damage of the pipe causes carbon powder leakage. Even if thick-walled wear-resistant pipes or ceramic pipes are used as powder spray pipes, it is still impossible to avoid the risk of carbon powder particles leaking into the oxygen pipe of the cluster oxygen gun after the powder spray pipe is worn through by carbon particles, causing an explosion. At present, a simple thick-walled steel pipe is generally fixed in a single hole of a copper water tank installed on the wall of an electric furnace, as a conveying pipe to spray carbon powder into the electric furnace. The cluster oxygen gun is installed in parallel with it in the copper water tank or the two are completely separated. After the carbon powder is sprayed from the steel pipe, it falls rapidly due to its own gravity. Most of the carbon powder particles fall into a position close to the wall of the electric furnace, and it is impossible to spray at a longer distance to reach a position closer to the center of the electric furnace. The spray distance of carbon powder cannot meet the process requirements. Even if the toner gun uses a replaceable ceramic tube, there is still a need to increase the life of the toner spray gun, reduce the cost of manufacturing the toner spray gun, and reduce the need for thermal shutdowns by the manufacturer.

[0005] The study found that the particle size of the powder spraying particles is positively correlated with the depth of the particles injected into the melt, but the larger the particle size of the powder, the easier it is to wear through the powder spraying tube. Therefore, it is necessary to study a more reasonable powder spraying gun structure to solve the problem of production accidents caused by the wear of the powder spraying tube. Summary of the invention

[0006] In view of this, the purpose of the present invention is to provide an electric furnace ring hole cluster powder spraying oxygen lance, which can realize multiple functions such as oxygen blowing, combustion and powder spraying in the electric arc furnace smelting process, and facilitate daily maintenance and repair of the equipment and replacement of damaged parts.

[0007] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: an electric furnace annular hole clustered powder spraying oxygen gun, comprising a clustered nozzle assembly, a water-cooling pipe assembly arranged on the periphery of the clustered nozzle assembly, and a carbon powder nozzle assembly partially inserted into the clustered nozzle assembly and installed; the carbon powder nozzle assembly comprises a carbon powder inlet, a powder inlet pipe, a powder distributor, a sealing flange plate, a wear-resistant powder spraying pipe, a carbon powder nozzle and a powder leakage protection pipe; the clustered nozzle assembly comprises an oxygen inlet, an annular gas inlet, an oxygen pipe, an annular gas channel and a clustered jet nozzle, and the clustered jet nozzle is composed of a gas nozzle and an oxygen nozzle; the water-cooling pipe assembly comprises a cooling water inlet, a water-cooling pipe and a cooling water outlet.

[0008] Optionally, the beam jet nozzle and the carbon powder nozzle are installed on the inner side of the refractory material or water-cooled furnace wall of the electric arc furnace, and the angle between the axis of the beam jet nozzle and the carbon powder nozzle and the vertical line is controlled within the range of 41 to 43°. The cooling water inlet, cooling water outlet, ring gas inlet, oxygen inlet and carbon powder inlet are installed on the outer side of the refractory material or water-cooled furnace wall of the electric arc furnace.

[0009] Optionally, a wear-resistant powder spray pipe is inserted into the cluster nozzle assembly and arranged at the center of the cluster nozzle assembly, a powder leakage protection pipe is arranged on the periphery of the wear-resistant powder spray pipe and a gap is arranged along the direction of the sealing flange plate, and the gap at the carbon powder nozzle at the end of the wear-resistant powder spray pipe is zero, and a powder leakage warning hole is arranged on the sealing flange plate. The powder leakage warning hole is communicated with the gap between the wear-resistant powder spray pipe and the powder leakage protection pipe. When the powder spray pipe is worn through by high-speed carbon powder, the powder passes through the leakage hole into the gap between the powder spray pipe and the protection pipe, and some powder flows out from the warning hole, indicating that the wear-resistant ceramic nozzle needs to be replaced in time.

[0010] Optionally, the powder inlet pipe, the powder distributor and the wear-resistant powder spraying pipe are detachably connected. After the powder inlet pipe and the powder distributor are pulled out, the water-cooling pipe assembly and the cluster nozzle assembly still form a complete cluster oxygen gun.

[0011] Optionally, the inner wall of the water-cooling tube and the outer wall of the oxygen tube form a ring gas channel, and the inner wall of the oxygen tube and the outer wall of the powder leakage protection tube form an oxygen channel. Oxygen and the ring gas are mixed and burned in the combustion chamber on the inner wall of the water-cooling tube assembly to form a high-temperature clustered jet, thereby realizing the oxygen blowing decarburization and combustion heating functions of the ring-hole clustered oxygen gun.

[0012] Optionally, the oxygen channel is provided with a variable-section annular structure at one end close to the combustion chamber, and the variable-section annular structure is an annular variable-section nozzle composed of a convergent tube and an expander tube. Oxygen with a pressure greater than 0.2 MPa is accelerated into a supersonic oxygen jet through the annular variable-section nozzle.

[0013] Optionally, the carbon powder nozzle assembly is located at the center of the cluster nozzle assembly, and the carrier gas carries the powder out from the wear-resistant powder spray pipe, and the protective gas flows out from the annular nozzle between the outer wall of the powder leakage protection pipe and the oxygen pipe, forming an annular protective air curtain for the powder, which makes the powder spray distance farther and thus increases the amount of powder entering the molten steel pool.

[0014] Optionally, the carrier gas is argon or nitrogen or air or carbon dioxide gas, the protective gas is oxygen or nitrogen or argon or carbon dioxide gas, and the powder is carbon powder or anthracite powder or lime powder or limestone powder.

[0015] Optionally, cooling water flows inside the water-cooling pipe assembly, flows in from the cooling water inlet, and flows out from the cooling water outlet, taking away the radiant heat received by the water-cooling gun body in a high-temperature environment, protecting the annular hole cluster powder spray oxygen gun and extending its service life.

[0016] The beneficial effects of the present invention are:

[0017] 1) The electric furnace annular hole clustered powder spraying oxygen lance of the present invention integrates the clustered oxygen blowing and powder spraying functions, can blow oxygen, burn and spray powder, and reduces the number of chemical energy input devices for the electric furnace and the space occupied;

[0018] 2) The electric furnace ring hole cluster powder spray oxygen gun of the present invention solves the problem of timely discovering that carbon particles have worn through the powder spray pipe, isolates carbon powder from entering the oxygen pipe, and avoids the risk of explosion;

[0019] 3) The electric furnace ring hole cluster powder spraying oxygen gun of the present invention realizes the function of long-distance carbon powder spraying, and can transport carbon powder to the electrode circle area, so as to quickly generate foam slag to bury the arc and protect the electric furnace water cooling frame and furnace wall refractory;

[0020] 4) The electric furnace annular hole clustered powder spray oxygen gun of the present invention is easy to maintain and repair. The powder spray pipe can be pulled out and replaced by removing the bolts on the sealing flange, which reduces the time for maintenance personnel to work in a high-temperature working environment.

[0021] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0023] Figure 1It is a schematic diagram of the structure and installation method of an electric furnace annular hole clustered powder spray oxygen gun of the present invention;

[0024] Figure 2 It is a structural schematic diagram of a carbon powder spray pipe assembly of an electric furnace annular hole clustered powder spray oxygen gun of the present invention;

[0025] Figure 3 The present invention is a schematic structural diagram of the remaining cluster spray gun components after removing part of the carbon powder spray pipe components of an electric furnace annular hole cluster powder spray oxygen gun of the present invention.

[0026] Figure numerals: water-cooling pipe assembly 1, cooling water inlet 11, cooling water outlet 12, water-cooling pipe 13, carbon powder nozzle assembly 2, carbon powder inlet 21, powder inlet pipe 22, powder distributor 23, sealing flange plate 24, wear-resistant powder spray pipe 25, carbon powder nozzle 26, powder leakage protection pipe 27, powder leakage warning hole 28, cluster nozzle assembly 3, oxygen inlet 31, ring gas inlet 32, oxygen pipe 33, gas nozzle 34, oxygen nozzle 35, ring gas channel 36, convergent pipe 37, divergent pipe 38, oxygen channel 39, combustion chamber 4. DETAILED DESCRIPTION

[0027] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0028] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0029] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0030] See also Figure 1 to Figure 3 , which is an electric furnace annular hole cluster powder spraying oxygen gun, including a cluster nozzle assembly 3, a water cooling pipe assembly 1 arranged on the periphery of the cluster nozzle assembly 3, and a carbon powder nozzle assembly 2 partially inserted into the cluster nozzle assembly 3; the water cooling pipe assembly 1, the cluster nozzle assembly 3 and the carbon powder nozzle assembly 2 are connected into one body through a sealing flange and bolts to form a multi-layer sleeve spray gun, which has the functions of thermal protection, cluster blowing, combustion heating, long-distance powder spraying and powder leakage warning, and is applied to the electric arc furnace smelting process. Among them, the carbon powder nozzle assembly 2 includes a carbon powder inlet 21, a powder inlet pipe 22, a powder distributor 23, a sealing flange plate 24, a wear-resistant powder spraying pipe 25, a carbon powder nozzle 26 and a powder leakage protection pipe 27; the cluster nozzle assembly 3 includes an oxygen inlet 31, an annular gas inlet 32, an oxygen pipe 33, an annular gas channel 36 and a cluster jet nozzle, which is composed of a gas nozzle 34 and an oxygen nozzle 35; the water cooling pipe assembly 1 includes a cooling water inlet 11, a water cooling pipe 13 and a cooling water outlet 12.

[0031] like Figure 1 As shown, the beam jet nozzle and the carbon powder nozzle 26 are installed on the inner side of the refractory material or the water-cooled furnace wall of the electric arc furnace, the angle between the axis of the beam jet nozzle and the carbon powder nozzle 26 and the vertical line is controlled within the range of 41 to 43°, and the cooling water inlet 11, the cooling water outlet 12, the ring gas inlet 32, the oxygen inlet 31, and the carbon powder inlet 21 are installed on the outer side of the refractory material or the water-cooled furnace wall of the electric arc furnace.

[0032] like Figure 2As shown, the wear-resistant powder spraying pipe 25 is inserted into the cluster nozzle assembly 3 and arranged at the center position of the cluster nozzle assembly 3, and the carbon powder is sprayed from the wear-resistant powder spraying pipe 25 into the molten pool. The powder leakage protection pipe 27 is arranged on the periphery of the wear-resistant powder spraying pipe 25 to isolate the powder leaked from the powder spraying pipe from the oxygen pipe 33 to prevent the leaked powder from entering the oxygen pipe 33 and exploding. The powder leakage protection pipe 27 is provided with a gap along the sealing flange plate 24, and the gap at the carbon powder nozzle 26 at the end of the wear-resistant powder spraying pipe 25 is zero. A powder leakage warning hole 28 is provided on the sealing flange plate 24, and the powder leakage warning hole 28 is communicated with the gap between the wear-resistant powder spraying pipe 25 and the powder leakage protection pipe 27. When the powder spraying pipe is worn through by the high-speed carbon powder, the powder passes through the leakage hole into the gap between the powder spraying pipe and the protection pipe, and part of the powder flows out from the warning hole, indicating that the wear-resistant ceramic spraying pipe needs to be replaced in time.

[0033] In this embodiment, the powder inlet pipe 22, the powder distributor 23 and the wear-resistant powder spraying pipe 25 are detachably connected. After the powder inlet pipe 22 and the powder distributor 23 are pulled out, the water-cooling pipe assembly 1 and the cluster nozzle assembly 3 still form a complete cluster oxygen gun. The inner wall of the water-cooling pipe 13 and the outer wall of the oxygen pipe 33 constitute an annular gas channel 36. The inner wall of the oxygen pipe 33 and the outer wall of the powder leakage protection pipe 27 constitute an oxygen channel 39. Oxygen and the annular gas are mixed and burned in the combustion chamber 4 on the inner wall of the water-cooling pipe assembly 1 to form a high-temperature cluster jet, thereby realizing the oxygen blowing decarburization and combustion heating functions of the annular hole cluster oxygen gun. The oxygen channel 39 is provided with a variable cross-section annular structure at one end close to the combustion chamber 4, and the variable cross-section annular structure is an annular variable cross-section nozzle composed of a convergent tube 37 and an expander tube 38. Oxygen with a pressure greater than 0.2MPa is accelerated into a supersonic oxygen jet through the annular variable cross-section nozzle, and the combustion gas flows out from the annular combustion gas channel 36 and mixes with the outer layer oxygen of part of the supersonic oxygen jet to burn in the combustion chamber 4 to generate a high-temperature and high-speed airflow, thereby isolating the supersonic oxygen jet from the entrainment effect on the atmosphere, extending the injection distance of the supersonic oxygen jet, and increasing the impact force of the supersonic oxygen jet on the molten steel surface.

[0034] In this embodiment, the oxygen pipe 33 is installed in the water-cooling pipe assembly 1 through a sealing flange, and a sealed cavity connected to the oxygen inlet 31 is formed between the sealing flange plate 24 of the carbon powder nozzle assembly 2 and the sealing flange of the oxygen pipe 33. The oxygen channel 39 and the ring gas channel 36 are independent channels and are respectively connected to the oxygen inlet 31 and the ring gas inlet 32.

[0035] The cooling water flows inside the water-cooling pipe assembly 1, flows in from the cooling water inlet 11, and flows out from the cooling water outlet 12, taking away the radiant heat received by the water-cooling gun body in a high temperature environment, protecting the annular hole cluster powder spray oxygen gun and extending its service life.

[0036] The carbon powder nozzle assembly 2 is located at the center of the cluster nozzle assembly 3. The carrier gas carries the powder out from the wear-resistant powder spraying tube 25, and the protective gas flows out from the annular nozzle between the outer wall of the powder leakage protection tube 27 and the oxygen tube 33, forming an annular protective air curtain for the powder, which makes the spray distance of the powder farther, thereby increasing the amount of powder entering the molten steel pool.

[0037] In production and use, when the wear-resistant powder spraying tube 25 is damaged, the bolts can be removed and the carbon powder spraying tube assembly 2 can be directly pulled out for quick replacement.

[0038] Metallurgical powders such as carbon powder or lime powder can be sprayed into the arc furnace molten pool with the help of carrier gas; the carrier gas for conveying metallurgical powders such as lime powder can be compressed air, oxygen, nitrogen, argon, carbon dioxide and other gases; and the carrier gas for conveying carbon powder is generally compressed air, nitrogen, argon, carbon dioxide and other gases; the protective gas used in production is oxygen, nitrogen, argon, carbon dioxide and other gases, and the gas for cluster combustion can be various combustible gases such as coal gas, natural gas, liquefied petroleum gas, etc.

[0039] In this embodiment, the annular hole clustered powder spray oxygen lance can also be installed on the steel-making converter for heating and melting scrap steel, carbon addition and heat supplement, oxygen blowing and decarburization and other metallurgical processes.

[0040] The invention discloses an electric furnace annular hole clustered powder spraying oxygen lance, which has multiple metallurgical functions such as oxygen spraying blowing, powder spraying agent smelting, combustion heating and melting of scrap steel, etc.; at the same time, the invention can timely discover powder leakage of the powder spraying pipe, avoid explosion of the oxygen lance, extend the service life of the oxygen lance, facilitate the maintenance of the carbon powder spraying pipe, reduce the maintenance operation time in the high temperature zone, and reduce the production cost.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. An electric furnace ring hole cluster powder spray oxygen lance, characterized in that: It includes a cluster nozzle assembly, a water cooling pipe assembly arranged on the periphery of the cluster nozzle assembly, and a carbon powder nozzle assembly partially inserted into the cluster nozzle assembly for installation; The carbon powder spray pipe assembly includes a carbon powder inlet, a powder inlet pipe, a powder distributor, a sealing flange plate, a wear-resistant powder spray pipe, a carbon powder nozzle and a powder leakage protection pipe; The cluster nozzle assembly includes an oxygen inlet, an annular gas inlet, an oxygen pipe, an annular gas channel and a cluster jet nozzle, and the cluster jet nozzle is composed of a gas nozzle and an oxygen nozzle; The water cooling pipe assembly comprises a cooling water inlet, a water cooling pipe and a cooling water outlet.

2. The electric furnace annular hole clustered powder spray oxygen lance according to claim 1, characterized in that: The focused jet nozzle and the carbon powder nozzle are installed on the inner side of the refractory material or the water-cooled furnace wall of the electric arc furnace. The angle between the axis of the focused jet nozzle and the carbon powder nozzle and the vertical line is controlled within the range of 41 to 43°. The cooling water inlet, cooling water outlet, ring gas inlet, oxygen inlet and carbon powder inlet are installed on the outer side of the refractory material or the water-cooled furnace wall of the electric arc furnace.

3. The electric furnace annular hole clustered powder spray oxygen lance according to claim 1, characterized in that: The wear-resistant powder spray pipe is inserted into the cluster nozzle assembly and is arranged at the center of the cluster nozzle assembly. The powder leakage protection pipe is arranged on the periphery of the wear-resistant powder spray pipe and a gap is arranged along the sealing flange plate direction. The gap at the carbon powder nozzle position at the end of the wear-resistant powder spray pipe is zero. A powder leakage warning hole is arranged on the sealing flange plate. The powder leakage warning hole is communicated with the gap between the wear-resistant powder spray pipe and the powder leakage protection pipe. When the powder spray pipe is worn through by high-speed carbon powder, the powder passes through the leakage hole into the gap between the powder spray pipe and the protection pipe, and some powder flows out from the warning hole, indicating that the wear-resistant ceramic spray pipe needs to be replaced in time.

4. The electric furnace annular hole clustered powder spray oxygen lance according to claim 3, characterized in that: The powder inlet pipe, the powder distributor and the wear-resistant powder spraying pipe are detachably connected. After the powder inlet pipe and the powder distributor are pulled out, the water-cooling pipe assembly and the cluster nozzle assembly still form a complete cluster oxygen gun.

5. The electric furnace annular hole clustered powder spray oxygen lance according to claim 1, characterized in that: The inner wall of the water-cooling tube and the outer wall of the oxygen tube form a ring gas channel, and the inner wall of the oxygen tube and the outer wall of the powder leakage protection tube form an oxygen channel. Oxygen and the ring gas are mixed and burned in the combustion chamber on the inner wall of the water-cooling tube assembly to form a high-temperature clustered jet, realizing the oxygen blowing decarburization and combustion heating functions of the ring-hole clustered oxygen gun.

6. The electric furnace annular hole clustered powder spray oxygen lance according to claim 5, characterized in that: The oxygen channel is provided with a variable cross-section annular structure at one end close to the combustion chamber. The variable cross-section annular structure is an annular variable cross-section nozzle composed of a convergent tube and an expander tube. Oxygen with a pressure greater than 0.2MPa is accelerated into a supersonic oxygen jet through the annular variable cross-section nozzle.

7. The electric furnace annular hole clustered powder spray oxygen lance according to claim 1, characterized in that: The carbon powder nozzle assembly is located in the center of the cluster nozzle assembly. The carrier gas carries the powder out of the wear-resistant powder spraying tube, and the protective gas flows out from the annular nozzle between the outer wall of the powder leakage protection tube and the oxygen tube, forming an annular protective air curtain for the powder, which makes the powder spray distance farther and increases the amount of powder entering the molten steel pool.

8. The electric furnace annular hole clustered powder spray oxygen lance according to claim 7, characterized in that: The carrier gas is argon or nitrogen or air or carbon dioxide gas, the protective gas is oxygen or nitrogen or argon or carbon dioxide gas, and the powder is carbon powder or anthracite powder or lime powder or limestone powder.

9. The electric furnace annular hole clustered powder spray oxygen lance according to claim 1, characterized in that: The cooling water flows inside the water-cooling pipe assembly, flows in from the cooling water inlet, and flows out from the cooling water outlet, taking away the radiant heat received by the water-cooling gun body in a high-temperature environment, protecting the annular hole cluster powder spray oxygen gun and extending its service life.

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