Multifunctional steel-making oxygen lance

Abstract

The utility model belongs to the field of ferrous metallurgical equipment, and relates to a multifunctional steel-making oxygen lance, in particular to a multi-layer sleeve top-blowing oxygen lance which is formed by connecting and combining an oxygen lance hanging bracket assembly and a water-cooling lance body assembly into a whole through a sealing flange and a bolt. The device has multiple metallurgical functions such as oxygen blowing, powder smelting and molten steel heating by burning coke oven gas, and multiple equipment maintenance functions such as roasting of a smelting container, melting of cold steel and monitoring of burning flame. A fuel gas powder spraying pipe of the oxygen lance hanging bracket assembly is directly inserted into a cooling water annular plug of the water cooling lance body assembly, a high-pressure oxygen flowing channel and a fuel gas powder channel of a supersonic speed oxygen jet flow which are coaxial can be formed without welding or rubber ring sealing at the position of a spraying head, and fuel gas or powder flows out of the interior of the supersonic speed oxygen jet flow. The damage of thermal expansion and cold contraction displacement between sleeves of a traditional oxygen lance nozzle is eliminated, the service life of the oxygen lance is prolonged, and the nozzle is convenient to maintain and repair.

Description

Technical Field

[0001] The utility model belongs to the field of steel metallurgical equipment and relates to a multifunctional steelmaking oxygen lance. Background Art

[0002] After the introduction of RH vacuum refining technology in China, the rubber seal inside the RH top lance nozzle was moved to the rear of the lance, improving the rubber seal's ambient temperature and extending its service life. It wasn't until 2014, when MCC SEDI released its patented annular hole top lance technology, that the oxygen lance nozzle ended its nearly 140-year history of producing supersonic oxygen jets solely using circular hole Laval tubes. Now, annular hole supersonic jets can be produced, and gas or powder can be sprayed within the supersonic jet.

[0003] RH top gun is composed of coaxial or co-directional multi-layer casing (KTB top gun nozzle has at least four casings, MFB top gun nozzle has more than eight casings, as shown in the attached Figure 4 As shown in the figure, each sleeve needs to be positioned axially and circumferentially. The RH top gun extends into the vacuum tank, and the working environment temperature is as high as 1400℃ or above. Thermal expansion and contraction cause mutual displacement between the sleeves, so the two ends of each sleeve cannot be welded and fixed at the same time. Therefore, the traditional top gun nozzle structure uses rubber sealing rings to solve the medium sealing problem and sleeve displacement problem of the sleeve. However, the reliability of the rubber sealing ring is reduced at high temperature, and the annular top gun uses a special structure to position the core tube axially and circumferentially, which actually increases the manufacturing difficulty. Therefore, it is necessary to study a more reasonable RH top gun structure to solve the problems of axial positioning and circumferential positioning of the core tube under its thermal expansion and contraction conditions. Utility Model Content

[0004] In view of this, the purpose of the present invention is to provide a multifunctional steelmaking oxygen lance that can realize multiple functions such as oxygen blowing, combustion and powder spraying in the RH vacuum refining process, and facilitate the daily maintenance and repair of the equipment and replacement of damaged parts.

[0005] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a multifunctional steelmaking oxygen lance, comprising an oxygen lance hanger assembly and a water-cooled lance body assembly which are combined into one by a bolt sealing connection; the oxygen lance hanger assembly is composed of a hanger plate, a hanger shaft, an oxygen inlet pipe, a gas powder casing, a gas sealing flange and a flame detection sensor interface flange and are welded into one; the water-cooled lance body assembly is composed of a cooling water inlet pipe, a cooling water outlet pipe, a lance body outer pipe, a lance body inner pipe, a water riser, a cooling water annular plug and a cooling water sealing flange and are welded into a hollow three-layer casing assembly; the gas powder casing of the oxygen lance hanger assembly is inserted into the cooling water annular plug of the water-cooled lance body assembly to form circumferential positioning, a sealing rubber part is provided between the gas sealing flange and the cooling water sealing flange, and the gas sealing flange is pressed and sealed by bolts after contacting the cooling water sealing flange to realize axial positioning of the gas powder casing in the water-cooled lance body assembly, so that the oxygen lance hanger assembly and the water-cooled lance body assembly form a four-layer coaxial casing water-cooled oxygen lance.

[0006] Optionally, two hanging plates are provided, which are fixedly connected to the fuel gas powder casing and the oxygen input pipe respectively, and the hanging shaft is provided between the tops of the two hanging plates.

[0007] Optionally, a flame detection sensor interface flange is welded to the upper part of the gas powder casing. A flame detection sensor is installed on the flame detection sensor interface flange to continuously monitor the ultraviolet rays generated when the coke oven gas is burned. When the flame is extinguished, the gas valve is automatically closed to avoid safety accidents such as explosion caused by gas accumulation.

[0008] Optionally, a cooling water cavity is formed between the outer tube of the gun body and the outer tube of the gun body, a water riser is arranged in the cooling water cavity, and the cooling water cavity is divided into a circulating cooling loop respectively connected to the cooling water inlet pipe and the cooling water outlet pipe. The cooling water flows in from the cooling water inlet pipe and flows out from the cooling water outlet pipe, taking away the radiant heat received by the water-cooled gun body in a high temperature environment, thereby protecting the steelmaking oxygen gun and extending its service life.

[0009] Optionally, after the gas powder sleeve is inserted into the water-cooled gun body assembly, the outer wall of the gas powder sleeve is connected to the inner wall of the gun body tube and the oxygen input pipe to form a protective gas passage, and a cooling water annular plug is set at the end of the protective gas passage.

[0010] Optionally, the annular nozzle between the cooling water annular plug and the gas powder casing is an annular variable-section nozzle connected by a convergent tube and a divergent tube. Oxygen with a pressure greater than 0.2 MPa is accelerated to supersonic speed through the annular variable-section nozzle, forming a supersonic oxygen jet that can reach the molten steel surface. The coke oven gas flowing out of the gas powder casing is located at the center of the supersonic oxygen jet, and is mixed with oxygen and burned to generate high-temperature gas, which can increase the impact force of the supersonic oxygen jet on the molten steel surface.

[0011] Optionally, the transition portion between the convergent tube and the divergent tube is the nozzle throat, through which the gas powder casing is circumferentially positioned.

[0012] Optionally, the protective gas passage is fed with protective gas, which is oxygen, nitrogen, argon or carbon dioxide.

[0013] Optionally, the fuel gas powder casing input is carbon powder or lime powder metallurgical powder with inert gas as carrier gas, or lime powder metallurgical powder with oxygen as carrier gas, or natural gas or liquefied petroleum gas.

[0014] Optionally, the oxygen lance is used for converter steelmaking, electric furnace steelmaking, RH refining furnace steelmaking, VD / VOD refining furnace steelmaking, or molten iron three-deoxidation treatment.

[0015] The beneficial effects of the present invention are:

[0016] 1) The utility model provides a multifunctional steelmaking oxygen lance that can be welded into two components and then assembled to form a shape. The positioning method between the two components is simple and practical. The gas powder sleeve of the oxygen lance hanger assembly is inserted into the cooling water annular plug of the water-cooled lance body assembly. The sealing flange connecting the two can axially position the two, and the inner wall of the cooling water annular plug at the nozzle throat can circumferentially position the gas powder sleeve.

[0017] 2) The utility model provides a multifunctional steelmaking oxygen lance that is easy to maintain and repair. By removing the bolts on the sealing flange and pulling out the gas powder casing, the cooling water annular plug and the gas powder casing nozzle that have been damaged by high temperature and splashing can be maintained separately;

[0018] 3) The utility model is a multifunctional steelmaking oxygen lance with complete metallurgical functions, capable of blowing oxygen, burning and spraying powder, and monitoring the entire combustion process to avoid explosion hazards.

[0019] Other advantages, objectives, and features of the present invention will be described in detail in the following description and, to some extent, will be apparent to those skilled in the art upon examination and study of the following or may be learned from practice of the present invention. The objectives and other advantages of the present invention may be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] 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 with reference to the accompanying drawings, in which:

[0021] Figure 1 This is a schematic diagram of the overall structure of a multifunctional steelmaking oxygen lance of the utility model;

[0022] Figure 2This is a schematic structural diagram of a water-cooled lance body assembly of a multifunctional steelmaking oxygen lance of the present invention;

[0023] Figure 3 This is a schematic structural diagram of an oxygen lance hanger assembly for a multifunctional steelmaking oxygen lance according to the present invention;

[0024] Figure 4 Schematic diagrams of the nozzle structures of a traditional top lance, an improved top lance and the oxygen lance of the present invention, wherein a) is a KTB top lance nozzle, b) is an MFB top lance nozzle, c) is a domestic improved nozzle, and d) is a steelmaking oxygen lance nozzle of the present invention.

[0025] Figure markings: 1-oxygen gun hanger assembly; 2-water-cooled gun body assembly; 3-bolt; 4-sealing rubber part; 5-flame detection module; 101-gas powder casing; 102-oxygen inlet pipe; 103-hanging plate; 104-hanging shaft; 105-flame detection sensor interface flange; 106-gas sealing flange; 107-gas pipe nozzle; 201-cooling water inlet pipe; 202-cooling water outlet pipe; 203-cooling water sealing flange; 204-gun body outer tube; 205-waterproof pipe; 206-gun body tube; 207-cooling water annular plug. DETAILED DESCRIPTION

[0026] The following describes the embodiments of the present invention through specific examples. Those skilled in the art can easily understand the other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments. The details in this specification can also be modified or changed 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 are only schematic illustrations of the basic concept of the present invention. The following embodiments and the features in the embodiments can be combined with each other without conflict.

[0027] Among them, the accompanying drawings are only for illustrative purposes and represent only schematic diagrams rather than actual pictures, and should not be understood as limiting the present invention. In order to better illustrate the embodiments of the present invention, some parts of the accompanying drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product. For those skilled in the art, it is understandable that some well-known structures and their descriptions may be omitted in the accompanying drawings.

[0028] 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 there are terms such as "upper", "lower", "left", "right", "front", "back", etc. indicating directions or positional relationships, they are based on the directions or positional relationships shown in the drawings. This is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, the terms describing the positional 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.

[0029] See also Figures 1 to 4 This is a multifunctional steelmaking oxygen lance for use in RH vacuum refining furnaces. It has multiple metallurgical functions, including oxygen blowing, powder spraying, and heating molten steel with coke oven gas. It also has multiple equipment maintenance functions, including baking smelting vessels, melting cold steel, and monitoring combustion flames. The oxygen lance is simple to manufacture and easy to maintain. It includes an oxygen lance hanger assembly 1 and a water-cooled lance body assembly 2, which are hermetically connected and assembled into one body by bolts 3.

[0030] The oxygen lance hanger assembly 1 is composed of a hanger plate 103, a hanger shaft 104, an oxygen inlet pipe 102, a fuel gas powder casing 101, a gas sealing flange 106, and a flame detection sensor interface flange 105, which are welded together. The water-cooled lance body assembly 2 is composed of a cooling water inlet pipe 201, a cooling water outlet pipe 202, a lance body outer pipe 204, a lance body inner pipe 206, a water riser 205, a cooling water annular plug 207, and a cooling water sealing flange 203, which are welded together to form a hollow three-layer casing assembly.

[0031] In order to avoid internal stress caused by thermal expansion and contraction after the two ends of the gun body inner tube 206 and the gun body outer tube 204 are welded, the gun body inner tube 206 and the gun body outer tube 204 are respectively welded to the cooling water annular plug 207 at the water-cooled gun body nozzle part, and multiple sealing rings are used to seal between the gun body inner tube 206 and the gun body outer tube 204 at the tail of the water-cooled gun body.

[0032] The gas powder sleeve 101 of the oxygen gun hanger assembly 1 is inserted into the cooling water annular plug 207 of the water-cooled gun body assembly 2 to form circumferential positioning. A sealing rubber part 4 is provided between the gas sealing flange 106 and the cooling water sealing flange 203. After the gas sealing flange 106 and the cooling water sealing flange 203 come into contact, they are compressed and sealed by bolts 3 to achieve axial positioning of the gas powder sleeve 101 in the water-cooled gun body assembly 2, so that the oxygen gun hanger assembly 1 and the water-cooled gun body assembly 2 form a four-layer coaxial sleeve water-cooled oxygen gun.

[0033] In this embodiment, there is no rubber sealing ring at the oxygen lance nozzle. When the nozzle is damaged, the bolt 3 can be removed and the gas powder sleeve 101 can be directly pulled out, and the water-cooled plug of the water-cooled lance body assembly 2 and the gas pipe nozzle 107 of the oxygen lance hanger assembly 1 can be replaced and repaired respectively.

[0034] In this embodiment, there are two hanging plates 103, which are fixedly connected to the gas powder casing 101 and the oxygen inlet pipe 102 respectively. The hanging shaft 104 is arranged between the tops of the two hanging plates 103. The flame detection sensor interface flange 105 is welded to the upper part of the gas powder casing 101. The flame detection sensor is installed on the flame detection sensor interface flange 105 to continuously monitor the ultraviolet rays generated during the combustion of coke oven gas. When the flame is extinguished, the gas valve is automatically closed to avoid safety accidents such as explosion caused by gas accumulation. A cooling water cavity is formed between the gun body outer tube 204 and the gun body inner tube 206. The water riser 205 is arranged in the cooling water cavity and divides the cooling water cavity into a circulating cooling loop connected to the cooling water inlet pipe 201 and the cooling water output pipe 202 respectively. The cooling water flows in from the cooling water inlet pipe 201 and flows out from the cooling water output pipe 202, taking away the radiant heat received by the water-cooled gun body in a high temperature environment, protecting the steelmaking oxygen gun and extending its service life.

[0035] In production, the cooling water annular plug 207 of the water-cooled lance body and the gas and powder sleeve 101 of the lance hanger together form the dual-flow nozzle of the steelmaking oxygen lance. Powder flows out of the gas and powder sleeve 101, and shielding gas flows out of the annular nozzle between the cooling water annular plug 207 and the gas and powder sleeve 101, forming an annular protective gas curtain for the powder. This allows the powder to be sprayed farther, thereby increasing the amount of powder entering the molten steel pool and reducing the rate of powder loss due to vacuum airflow. Shielding gases used in production include oxygen, nitrogen, argon, carbon dioxide, and other gases.

[0036] In another operating condition, the cooling water annular plug 207 of the water-cooled gun body and the gas powder sleeve 101 of the oxygen gun hanger together constitute a double-channel nozzle of the steelmaking oxygen gun. The coke oven gas flows out from the gas powder sleeve 101, and the oxygen flows out from the annular nozzle between the cooling water annular plug 207 and the gas powder sleeve 101. The coke oven gas and oxygen are mixed and burned layer by layer outside the double-channel nozzle, forming a high-temperature rigid long flame of more than 1700°C that can reach the bottom of the vacuum tank, heating the molten steel in the molten pool and heating the refractory material of the vacuum tank.

[0037] The third production condition is to blow oxygen into the molten steel pool. Since the annular nozzle between the cooling water annular plug 207 and the gas powder casing 101 is an annular variable-section nozzle connected by a convergent pipe and a divergent pipe, oxygen with a pressure greater than 0.2 MPa can be accelerated to a supersonic speed through the annular variable-section nozzle, forming a supersonic oxygen jet that can reach the molten steel surface. The coke oven gas flowing out of the gas powder casing 101 is located at the center of the supersonic oxygen jet, and the combustion of the mixed gas with the oxygen to generate high-temperature gas can increase the impact force of the supersonic oxygen jet on the molten steel surface.

[0038] The transition portion between the annular convergent tube and the gradually expanding tube formed between the inner wall of the cooling water annular plug 207 and the outer wall of the gas powder sleeve 101 is the nozzle throat. The inner wall of the cooling water annular plug 207 at the nozzle throat realizes circumferential positioning of the gas powder sleeve 101.

[0039] In this embodiment, adjusting the pressure of the oxygen in the pipeline can adjust the oxygen supply flow rate of the oxygen jet online, and adjusting the throat cross-sectional area can change the oxygen flow rate at a specified pressure and the Mach number of the nozzle.

[0040] In this embodiment, cooling water flows in the water-cooled lance body, flows in from the cooling water inlet pipe 201 and flows out from the cooling water outlet pipe 202, taking away the radiant heat received by the water-cooled lance body in a high-temperature environment, protecting the steelmaking oxygen lance and extending its service life.

[0041] In this embodiment, a flame detection sensor interface flange 105 is welded to the upper part of the gas powder sleeve 101 of the oxygen gun hanger welding assembly. The flame detection sensor installed on the interface flange continuously monitors the ultraviolet rays generated during the combustion of coke oven gas and automatically closes the gas valve when the flame is extinguished, thereby avoiding safety accidents such as explosion caused by gas accumulation.

[0042] The fuel gas powder casing 101 of the present invention can be used to input metallurgical powders such as carbon powder or lime powder with inert gas as carrier gas; can also be used to input metallurgical powders such as lime powder with oxygen as carrier gas; and can also be used to input various fuel gases such as natural gas and liquefied petroleum gas.

[0043] In this embodiment, the multifunctional steelmaking oxygen lance can also be used for converter steelmaking, electric furnace steelmaking, RH refining furnace steelmaking, VD / VOD refining furnace steelmaking and molten iron three-desulfurization treatment.

[0044] The advantages of this embodiment are: the multi-layer sleeve top-blowing oxygen lance, which is composed of an oxygen lance hanger assembly 1 and a water-cooled lance body assembly 2 connected and assembled into one body by a sealing flange and bolts 3, has multiple metallurgical functions such as oxygen blowing, powder smelting, and heating molten steel by burning coke oven gas, as well as multiple equipment maintenance functions such as baking smelting containers, melting cold steel, and monitoring combustion flames. The gas and powder nozzle of the oxygen lance hanger assembly 1 is directly inserted into the cooling water annular plug 207 of the water-cooled lance body assembly 2. No welding or rubber ring sealing is required at the nozzle position, and a coaxial high-pressure oxygen flow channel and gas and powder channel for the supersonic oxygen jet can be formed. The gas or powder flows out from the inside of the supersonic jet. The utility model eliminates the hazards of thermal expansion and contraction displacement between the traditional oxygen lance nozzle sleeves, extends the service life of the oxygen lance, and facilitates nozzle maintenance.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model and are not limiting. Although the utility model is described in detail with reference to the preferred embodiments, ordinary technicians in this field should understand that the technical solution of the utility model 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 utility model.

Claims

1. A multifunctional steelmaking oxygen lance, characterized by: It includes an oxygen lance hanger assembly and a water-cooled lance body assembly which are combined into one body by bolt sealing connection; The oxygen gun hanger assembly consists of a hanger plate, a hanger shaft, an oxygen input pipe, a fuel gas powder casing, a gas sealing flange and a flame detection sensor interface flange, which are welded together; The water-cooled gun body assembly is composed of a cooling water inlet pipe, a cooling water outlet pipe, a gun body outer pipe, a gun body outer pipe, a water riser, a cooling water annular plug, and a cooling water sealing flange and is welded into a hollow three-layer casing assembly; The gas powder sleeve of the oxygen gun hanger assembly is inserted into the cooling water annular plug of the water-cooled gun body assembly to form circumferential positioning. A sealing rubber part is provided between the gas sealing flange and the cooling water sealing flange. After the gas sealing flange and the cooling water sealing flange come into contact, they are tightened and sealed by bolts to achieve axial positioning of the gas powder sleeve in the water-cooled gun body assembly, so that the oxygen gun hanger assembly and the water-cooled gun body assembly form a four-layer coaxial sleeve water-cooled oxygen gun.

2. The multifunctional steelmaking oxygen lance according to claim 1, characterized in that: There are two hanging plates, which are fixedly connected to the fuel gas powder casing and the oxygen input pipe respectively, and the hanging shaft is arranged between the tops of the two hanging plates.

3. The multifunctional steelmaking oxygen lance according to claim 1, characterized in that: The flame detection sensor interface flange is welded to the upper part of the gas powder casing. A flame detection sensor is installed on the flame detection sensor interface flange to continuously monitor the ultraviolet rays generated when the coke oven gas is burned. When the flame is extinguished, the gas valve is automatically closed to avoid safety accidents such as explosion caused by gas accumulation.

4. The multifunctional steelmaking oxygen lance according to claim 1, characterized in that: A cooling water cavity is formed between the outer tube of the lance body and the outer tube of the lance body. The water riser is arranged in the cooling water cavity, and the cooling water cavity is divided into a circulating cooling loop which is respectively connected to the cooling water inlet pipe and the cooling water outlet pipe. The cooling water flows in from the cooling water inlet pipe and flows out from the cooling water outlet pipe, taking away the radiant heat received by the water-cooled lance body in a high temperature environment, thereby protecting the steelmaking oxygen lance and extending its service life.

5. The multifunctional steelmaking oxygen lance according to claim 1, characterized in that: After the gas powder sleeve is inserted into the water-cooled gun body assembly, the outer wall of the gas powder sleeve is connected to the inner wall of the gun body tube and the oxygen input pipe to form a protective gas passage, and a cooling water annular plug is arranged at the end of the protective gas passage.

6. The multifunctional steelmaking oxygen lance according to claim 5, characterized in that: The annular nozzle between the cooling water annular plug and the gas powder casing is an annular variable-section nozzle connected by a convergent pipe and a divergent pipe. Oxygen with a pressure greater than 0.2MPa is accelerated to supersonic speed through the annular variable-section nozzle, forming a supersonic oxygen jet that can reach the molten steel surface. The coke oven gas flowing out of the gas powder casing is located at the center of the supersonic oxygen jet, and is mixed with oxygen to burn to generate high-temperature gas, which can increase the impact force of the supersonic oxygen jet on the molten steel surface.

7. The multifunctional steelmaking oxygen lance according to claim 6, characterized in that: The transition portion between the convergent tube and the divergent tube is the nozzle throat, through which the gas powder casing is circumferentially positioned.

8. The multifunctional steelmaking oxygen lance according to claim 5, characterized in that: The shielding gas is introduced into the shielding gas passage, and the shielding gas is oxygen, nitrogen, argon or carbon dioxide gas.

9. The multifunctional steelmaking oxygen lance according to claim 1, characterized in that: The fuel gas powder casing input is carbon powder or lime powder metallurgical powder with inert gas as carrier gas, or lime powder metallurgical powder with oxygen as carrier gas, or natural gas, liquefied petroleum gas.

10. The multifunctional steelmaking oxygen lance according to claim 1, characterized in that: The oxygen lance is used for converter steelmaking, electric furnace steelmaking, RH refining furnace steelmaking, VD / VOD refining furnace steelmaking or molten iron three-deoxidation treatment.

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