Long-acting oxygen lance nozzle

Abstract

The invention relates to a long-acting oxygen lance nozzle which comprises a nozzle body and a heat insulation anti-sticking outer hanging layer. The heat insulation anti-sticking outer hanging layer is arranged on the outer surface of the spray head body; wherein the heat insulation anti-sticking outer hanging layer is composed of a felt cloth layer and a graphite-rich layer; the felt cloth layer is arranged on the outer surface of the nozzle body; the graphite-rich layer is arranged on the outer surface of the felt cloth layer. The long-acting oxygen lance nozzle does not adhere to steel and slag, is good in heat insulation, can greatly prolong the service life, greatly reduces the purchase cost and production cost of the oxygen lance nozzle, and is easy to manufacture and convenient to use.

Description

Technical Field

[0001] The present invention relates to the technical field of converter steelmaking, and particularly to a long-lasting oxygen lance nozzle. Background Art

[0002] At present, oxygen lances are required for converter steelmaking worldwide, and the oxygen lance nozzle is a consumable part. It fails and needs to be replaced every 350 furnace heats on average, resulting in a slowdown in the production rhythm and an increase in costs.

[0003] Among them, the main reasons for the failure of the oxygen lance nozzle are: (1) The splashed molten steel or slag adheres to the oxygen lance nozzle. A large amount of heat is quickly transferred to the nozzle, forming thermal stress and grain coarsening caused by high temperature, and elements such as iron and carbon diffuse and migrate into the copper matrix of the nozzle, forming a Fe-Cu solid solution, which affects the thermal conductivity of copper; (2) The nozzle is baked at high temperature, causing the copper matrix grains to coarsen, resulting in the deformation of the spray holes or the cracking of the nozzle.

[0004] The invention patent with the patent number CN202310340898.6 discloses an oxygen lance for steelmaking. The entire inner surface of the spray holes of the nozzle or a part of the inner surface near the outlet end face of the nozzle, the outer peripheral surface of the nozzle, and the outlet end face of the nozzle are provided with an ultra-high temperature thermal barrier coating. The ultra-high temperature thermal barrier coating is a rare earth tantalate ceramic coating; the rare earth tantalate ultra-high temperature thermal barrier coating has the performance of working stably at high temperature, can effectively solve the problem of ablation prevention of the oxygen lance nozzle, extend the service life of the lance tip, reduce and prevent the occurrence of accidents such as the lance tip burning through and leaking water, prevent the rapid transfer of heat from the liquid steel slag to the surface of the nozzle, help reduce the cooling water supply, prevent the surface of the nozzle from being ablated, and the liquid slag cools slowly, so it is not easy to form slag and adhere to the surface of the nozzle, reducing the slag cleaning workload of the oxygen lance, and avoiding the occurrence of oxygen lance leakage accidents and backfires. However, the rare earth tantalate ultra-high temperature thermal barrier coating has good wettability with molten steel and slag and cannot avoid steel sticking and slag sticking.

[0005] The utility model patent with the patent number CN202222301534.0 discloses an oxygen lance nozzle. A plurality of air outlet holes are arranged on the body. One end of the body is provided with an oxygen channel. One end of the air outlet hole is communicated with the oxygen channel, and the other end is communicated with the outside. The plurality of air outlet holes are circumferentially distributed. The air outlet holes include a first air outlet hole and a second air outlet hole. The aperture of the first air outlet hole is larger than that of the second air outlet hole. The first air outlet hole and the second air outlet hole are arranged staggeredly. The first air outlet hole and the second air outlet hole form a certain angle ∠A with the axis of the body, and ∠A = 15°. The centers of the first air outlet hole and the second air outlet hole are located on the same circumference. It can improve the air flow intensity in the blank part of the liquid surface. The air flow force at the closest part between the first liquid surface and the second liquid surface is stronger, and the air flow intensity flowing to the blank part is also stronger. That is, it can strengthen the slagging surface, accelerate the reaction speed, reduce the smelting time, and at the same time reduce the erosion of the furnace wall and the scouring of the furnace bottom. However, the disclosed oxygen lance structure cannot alleviate the phenomena of steel sticking and slag sticking either.

[0006] In summary, the solutions disclosed in the prior art cannot effectively solve the above problems. Therefore, it is urgent to develop a long-lasting oxygen lance nozzle. Summary of the Invention

[0007] In view of the above problems, the purpose of the present invention is to provide a long-lasting oxygen lance nozzle, which can significantly reduce the heat introduced into the oxygen lance nozzle during smelting by reducing the thermal conductivity of the nozzle surface, thereby improving the service life of the oxygen lance nozzle, and at the same time can significantly alleviate the problems of steel sticking and slag sticking of the oxygen lance nozzle.

[0008] The technical solution adopted by the present invention is as follows:

[0009] A long-lasting oxygen lance nozzle proposed by the present invention includes a nozzle body and an adiabatic and anti-sticking outer layer; the adiabatic and anti-sticking outer layer is arranged on the outer surface of the nozzle body; wherein, the adiabatic and anti-sticking outer layer is composed of a felt layer and a graphite-rich layer; the felt layer is arranged on the outer surface of the nozzle body; the graphite-rich layer is arranged on the outer surface of the felt layer.

[0010] Further, the felt layer includes refractory felt and binder; the felt is attached to the outer surface of the nozzle body through the binder.

[0011] Further, the binder is water glass.

[0012] Further, the thickness of the felt layer is 1.5 - 10 mm.

[0013] Further, the graphite-rich layer includes magnesia sand, graphite powder and binder; the magnesia sand, graphite powder and binder are evenly mixed and then attached to the outer surface of the felt layer.

[0014] Further, the graphite content of the graphite-rich layer is 20% to 60%.

[0015] Further, the thickness of the graphite-rich layer is 2 to 30 mm.

[0016] Further, the surface roughness of the nozzle body in contact with the felt layer is Ra90 - 110 μm.

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] The oxygen lance nozzle proposed by the present invention does not stick to steel or slag, and has good heat insulation performance, which can greatly extend the service life, thereby greatly reducing the procurement cost and production cost of the oxygen lance nozzle. At the same time, it is easy to manufacture and convenient to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic main sectional structure view of the present invention;

[0020] Figure 2 is Figure 1 an enlarged structure view of I in

[0021] Figure 3 is a schematic bottom view structure of the present invention.

[0022] Among them, reference numerals: 1 - nozzle body; 2 - adiabatic and anti-sticking outer layer; 3 - felt layer; 4 - graphite-rich layer. DETAILED DESCRIPTION OF THE EMBODIMENTS

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

[0024] It should be noted that in the description of the present invention, the orientation or positional relationship indicated by the terms "upper", "lower", "top", "bottom", "one side", "the other side", "left", "right", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating that the device or element must have a specific orientation, be constructed and operated in a specific orientation.

[0025] As Figures 1-3 shown, a long-lasting oxygen lance nozzle proposed by the present invention includes a nozzle body 1 and an adiabatic and anti-sticking outer layer 2.

[0026] The adiabatic anti - sticking outer layer 2 is arranged on the outer surface of the spray head body 1 and does not interfere with each spray hole; the adiabatic anti - sticking outer layer 2 is composed of a felt layer 3 and a graphite - rich layer 4; the felt layer 3 is arranged on the outer surface of the spray head body 1; the graphite - rich layer 4 is arranged on the outer surface of the felt layer 3.

[0027] Among them, the felt layer 3 is composed of felt and binder; the felt is made of refractory materials such as asbestos; the felt is attached to the outer surface of the spray head body 1 through the binder; the binder is water glass; the thickness of the felt layer 3 is 1.5 - 10 mm.

[0028] The surface of the spray head body 1 in contact with the felt layer 3 is machined, and the roughness after machining is Ra90 - 110 μm, aiming to increase the bonding force between the spray head body 1 and the felt layer 3 by improving the surface roughness of the oxygen lance spray head body 1.

[0029] The graphite - rich layer 4 is composed of magnesia sand, graphite powder and binder; among them, the magnesia sand is used as aggregate to increase the overall strength of the graphite - rich layer 4, and the graphite powder and binder are used as filler and binder; the magnesia sand, graphite powder and binder are uniformly mixed and fully stirred into a mud - like state, and the whole is attached to the outer surface of the felt layer 3; the graphite content in the graphite - rich layer 4 is 20% - 60%; the thickness of the graphite - rich layer 4 is 2 - 30 mm; the binder is a refractory binder such as phenolic resin.

[0030] The working principle of the present invention is as follows:

[0031] The function of the graphite - rich layer 4: Because the wettability of graphite with molten steel and slag is very low, it can reduce the steel sticking and slag sticking of the spray head. At the same time, because of the high graphite content, its thermal shock resistance is good and it is not easy to crack due to thermal stress.

[0032] The function of the felt layer 3: First of all, because the thermal conductivity coefficient of the felt layer 3 is much lower than that of pure copper, it can greatly reduce the heat introduced into the oxygen lance spray head during smelting; water glass as a binder has stable chemical composition and no atoms of any element will penetrate into the oxygen lance spray head body 1 at the high temperature of converter smelting, so it can prevent the oxygen lance spray head body 1 from failing; secondly, the felt layer 3 can isolate the graphite - rich layer 4 from the oxygen lance spray head body 1, preventing carbon atoms from penetrating into the oxygen lance spray head body 1 at the high temperature of converter smelting, resulting in cracking, deformation or even failure of the oxygen lance spray head body 1; finally, it is difficult to bond between the oxygen lance spray head body 1 and the graphite - rich layer 4, and the felt layer 3 can be firmly bonded to the oxygen lance spray head body 1 and the graphite - rich layer 4 respectively, so that they can be firmly integrated into one body.

[0033] The effects of the present invention are further verified through specific embodiments as follows:

[0034] Embodiment 1:

[0035] 250-ton converter smelting:

[0036] 1. Prepare an oxygen lance nozzle, asbestos felt cloth, magnesia, graphite powder, and binder for a conventional 250-ton converter;

[0037] 2. Soak the asbestos felt cloth with water glass and stick it to the outer surface of the nozzle body 1 as shown, forming a "felt cloth layer 3" with a thickness of 1.5 mm; Figure 1 as shown, forming a "felt cloth layer 3" with a thickness of 1.5 mm;

[0038] 3. Thoroughly stir and mix magnesia, graphite powder, and the above refractory binder into a mud-like state. Among them, the graphite content in the graphite-rich layer 4 is 20%, and adhere it to the outer surface of the felt cloth layer 3 as shown, forming a "graphite-rich layer 4" with a thickness of 30 mm; Figure 1 as shown, forming a "graphite-rich layer 4" with a thickness of 30 mm;

[0039] 4. Bake the entire oxygen lance nozzle in a reducing atmosphere heating furnace;

[0040] 5. Take it out after cooling, polish the surface of the "graphite-rich layer 4" until it is shiny, and set it aside;

[0041] 6. Apply it to the daily production of a 250-ton converter.

[0042] In this embodiment, the service life of the oxygen lance nozzle is 3500 heats, while that of a conventional oxygen lance nozzle is 325 heats, and the service life is increased by 9.8 times.

[0043] Example 2:

[0044] 180-ton converter smelting:

[0045] 1. Prepare an oxygen lance nozzle, asbestos felt cloth, magnesia, graphite powder, and binder for a conventional 180-ton converter;

[0046] 2. Soak the asbestos felt cloth with water glass and stick it to the outer surface of the nozzle body 1 as shown, forming a "felt cloth layer 3" with a thickness of 10 mm; Figure 1 as shown, forming a "felt cloth layer 3" with a thickness of 10 mm;

[0047] 3. Thoroughly stir and mix magnesia, graphite powder, and the above refractory binder into a mud-like state. Among them, the graphite content in the graphite-rich layer 4 is 60%, and adhere it to the outer surface of the felt cloth layer 3 as shown, forming a "graphite-rich layer 4" with a thickness of 2 mm.; Figure 1 as shown, forming a "graphite-rich layer 4" with a thickness of 2 mm.;

[0048] 4. Bake the entire oxygen lance nozzle in a reducing atmosphere heating furnace;

[0049] 5. Take it out after cooling, polish the surface of the "graphite-rich layer 4" until it is shiny, and set it aside;

[0050] 6. Applied to the daily production of a 180-ton converter.

[0051] In this embodiment, the service life of the oxygen lance nozzle is 3,100 heats, while that of the conventional oxygen lance nozzle is 305 heats, and the service life is increased by 9.2 times.

[0052] Matters not detailed in the present invention are well-known technologies.

[0053] The embodiments described above are only used to describe the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A long-acting oxygen lance nozzle, comprising a nozzle body, characterized in that: It also includes a heat-insulating and anti-sticking external layer; the heat-insulating and anti-sticking external layer is arranged on the outer surface of the nozzle body; wherein the heat-insulating and anti-sticking external layer is composed of a felt cloth layer and a graphite-rich layer; the felt cloth layer is arranged on the outer surface of the nozzle body; the graphite-rich layer is arranged on the outer surface of the felt cloth layer.

2. A long-acting oxygen lance nozzle according to claim 1, characterized in that: The felt cloth layer comprises fire-resistant felt cloth and adhesive; the felt cloth is attached to the outer surface of the nozzle body through the adhesive.

3. A long-acting oxygen lance nozzle according to claim 2, characterized in that: The binder is water glass.

4. A long-acting oxygen lance nozzle according to claim 2, characterized in that: The thickness of the felt cloth layer is 1.5-10 mm.

5. The long-acting oxygen lance nozzle according to claim 1, characterized in that: The graphite-rich layer comprises magnesia sand, graphite powder and a binder; the magnesia sand, graphite powder and binder are uniformly mixed and then attached to the outer surface of the felt cloth layer.

6. A long-acting oxygen lance nozzle according to claim 5, characterized in that: The graphite content of the graphite-rich layer is 20% to 60%.

7. The long-acting oxygen lance nozzle according to claim 5, characterized in that: The thickness of the graphite-rich layer is 2 to 30 mm.

8. The long-acting oxygen lance nozzle according to claim 1, characterized in that: The surface roughness of the nozzle body in contact with the felt cloth layer is Ra90-110 μm.

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