Arrangement structure of asymmetric lifting pipe in RH refining furnace

Abstract

The utility model discloses an arrangement structure of an asymmetric lifting pipe in an RH refining furnace, which comprises a steel ladle used for containing molten steel, and an air brick is arranged at the bottom of the steel ladle; the RH furnace vacuum chamber is located above the steel ladle, the RH furnace vacuum chamber is provided with an ascending pipe, a descending pipe and a vacuum cavity, one end of the ascending pipe and one end of the descending pipe extend into the steel ladle, and the other ends of the ascending pipe and the descending pipe communicate with the vacuum cavity; the inner diameter of the descending pipe is larger than that of the ascending pipe. According to the lifting pipe, the descending pipe has a larger inner diameter than the ascending pipe, so that after molten steel is sucked from the ascending pipe, the flow rate of the degassed molten steel discharged from the descending pipe is reduced, and the degassed molten steel is more easily concentrated on the upper surface of a steel ladle and cannot sink to the bottom of the steel ladle due to higher flow rate to be mixed with non-degassed molten steel to participate in circulation again; and the refining efficiency is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of RH refining furnaces for steel smelting, and more specifically to an arrangement structure of asymmetric lifting pipes in the RH refining furnace. Background Art

[0002] The basic principle of the existing RH refining furnace is as follows: when the riser is inserted into the molten steel in the ladle, the vacuum pump starts to evacuate the vacuum chamber of the RH refining furnace, causing a pressure difference between the ladle and the vacuum chamber, and the molten steel rises from the riser to a height equal to the pressure difference. At the same time, the driving gas is blown into the riser through the air-permeable bricks at the bottom of the ladle. The gas expands due to heat and the pressure decreases, causing isothermal expansion, and the volume of the bubbles increases exponentially, making the specific gravity of the molten steel smaller, thereby driving the molten steel to rise through the riser and spraying it into the vacuum chamber like a fountain. As the bubbles burst, the molten steel becomes tiny droplets, which greatly increases the degassing surface area and accelerates the degassing process. The gas precipitates from the molten steel and is pumped away, while the degassed molten steel returns to the ladle through the downcomer due to the weight difference. The molten steel that has not been degassed continues to enter the vacuum chamber from the riser, thus forming a continuous cycle process, thereby achieving the refining purpose of degassing and improving the purity of the molten steel.

[0003] The optimization and improvement of the RH furnace mainly focuses on increasing the circulation flow of molten steel and improving the uniformity of molten steel in the ladle. The circulation flow is related to the lifting gas flow, while the uniformity of molten steel is related to the overall structural design of the RH furnace. The traditional lifting pipes, i.e., the riser and the downcomer, are generally arranged between the vacuum chamber and the ladle of the RH furnace in a symmetrical structural design, i.e., the diameter, length, and arrangement height of the riser and the downcomer are the same, such as CN115232922A-RH refining furnace and method for shortening the RH treatment cycle.

[0004] However, there are some problems with the symmetrical arrangement of the traditional riser and downcomer. For example, the lower pipe openings of the riser and downcomer are arranged close to the steel liquid surface and the lower pipe openings of the two are at the same height, so that the degassed molten steel discharged through the downcomer will be easily sucked back into the riser at the same height to participate in the circulation, which not only increases the number of steel liquid circulations, but also reduces the steel liquid refining efficiency; and the degassed molten steel discharged from the downcomer descends at a large speed, so that the degassed molten steel sinks to the bottom of the steel bunker and mixes with the non-degassed molten steel again and participates in the circulation, which is not conducive to the uniform and stable circulation of the molten steel; in addition, the lower pipe opening of the riser is far away from the air-permeable brick, so that the lifting gas flow entering the riser is small, which reduces the steel liquid circulation flow, thereby reducing the steel liquid refining efficiency.

[0005] Therefore, how to provide an arrangement structure of asymmetric lift pipes in an RH refining furnace that can reduce the number of molten steel circulations, facilitate the uniformity and stability of molten steel circulation, and improve the molten steel refining efficiency is an urgent problem that technical personnel in this field need to solve. Utility Model Content

[0006] In view of this, the utility model provides an arrangement structure of asymmetric lifting pipes in an RH refining furnace, which can reduce the number of molten steel circulations, facilitate the uniformity and stability of molten steel circulation, and improve the molten steel refining efficiency.

[0007] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0008] An arrangement structure of an asymmetric lift tube in a RH refining furnace, comprising:

[0009] A ladle, used to contain molten steel, wherein a gas-permeable brick is arranged at the bottom of the ladle;

[0010] an RH furnace vacuum chamber, which is located above the ladle, and is provided with an ascending tube, a descending tube and a vacuum chamber, one end of the ascending tube and one end of the descending tube respectively extend into the ladle, and the other ends are respectively communicated with the vacuum chamber;

[0011] Wherein, the inner diameter of the downcomer is larger than the inner diameter of the upcomer.

[0012] It can be seen from the above technical solution that, compared with the prior art, the utility model discloses an arrangement structure of an asymmetric riser in an RH refining furnace, wherein the downcomer has a larger inner diameter than the riser, so that after the molten steel is sucked from the riser, the flow rate of the degassed molten steel discharged from the downcomer will be reduced, making it easier for the degassed molten steel to be concentrated on the upper surface of the ladle, rather than sinking to the bottom of the ladle at a faster flow rate to mix with the non-degassed molten steel and participate in the circulation again, thereby causing the problem of reduced refining efficiency.

[0013] Furthermore, the inner diameter of the downcomer is 1.4-1.5 times the inner diameter of the upcomer.

[0014] The beneficial effect of adopting the above technical solution is that the flow rate of the degassed molten steel is relatively slow, and it is easy to concentrate on the upper surface of the ladle, and no longer mixes with the undegassed molten steel at the bottom of the ladle to participate in the circulation.

[0015] Furthermore, the lower pipe opening of the riser extends downward and is arranged close to the air-permeable brick, and the lower pipe opening of the downcomer is arranged close to the steel liquid surface and higher than the lower pipe opening of the riser.

[0016] The beneficial effect of adopting the above technical scheme is: the lower pipe opening of the riser and the lower pipe opening of the downcomer are not at the same height, that is, the lower pipe opening of the downcomer is close to the steel liquid surface, while the lower pipe opening of the riser is lower than the lower pipe opening of the downcomer and is closer to the air brick. In this way, when the degassed molten steel discharged through the downcomer with a larger inner diameter slowly enters the ladle and gathers on the upper surface of the ladle, because the lower pipe opening of the riser is lower than the lower pipe opening of the downcomer, the degassed molten steel enriched on the upper surface of the ladle will not be sucked in again by the riser, and the riser can only suck in the non-degassed molten steel at the bottom of the ladle. In this way, it can be ensured that the degassed molten steel will not mix with the non-degassed molten steel, the uniformity and stability of the molten steel circulation are ensured, and the number of degassed molten steel circulations is reduced. Moreover, because the lower pipe opening of the riser is closer to the air brick, a larger lifting gas flow rate can be obtained, the molten steel circulation flow rate is increased, and the steel refining efficiency is thereby improved.

[0017] Furthermore, the air-permeable brick is located directly below the lower pipe opening of the riser.

[0018] The beneficial effects of adopting the above technical solution are: the gas after passing through the breathable brick can directly and quickly enter the riser, thereby improving the steel liquid lifting circulation capacity of the riser, increasing the steel liquid circulation flow rate, and improving the steel liquid refining efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0020] Figure 1 The utility model provides a schematic structural diagram of an arrangement structure of an asymmetric lifting tube in an RH refining furnace.

[0021] Figure 2 Schematic diagram of molten steel flow. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0023] like Figure 1 As shown, the embodiment of the utility model discloses an arrangement structure of an asymmetric lift pipe in a RH refining furnace, comprising:

[0024] A ladle 1 is used to contain molten steel, and a gas-permeable brick 2 is provided at the bottom of the ladle 1;

[0025] The RH furnace vacuum chamber 3 is located above the ladle 1. The RH furnace vacuum chamber 3 is provided with an ascending tube 4, a descending tube 5 and a vacuum chamber 301. One end of the ascending tube 4 and one end of the descending tube 5 extend into the ladle 1 respectively, and the other ends are connected to the vacuum chamber 301 respectively.

[0026] The inner diameter of the downcomer 5 is larger than the inner diameter of the upcomer 4 .

[0027] The inner diameter of the downcomer 5 is 1.4-1.5 times the inner diameter of the upcomer 4 .

[0028] The lower pipe opening of the riser 4 extends downward and is arranged close to the air-permeable brick 2 , and the lower pipe opening of the downcomer 5 is arranged close to the molten steel level 6 and higher than the lower pipe opening of the riser 4 .

[0029] The air-permeable brick 2 is located directly below the lower pipe opening of the ascending pipe 4 .

[0030] The utility model adopts an asymmetric design of the riser, that is, the riser is longer than the downcomer in the RH furnace design, and the lower pipe opening of the riser is closer to the air-permeable brick and the downcomer has a larger inner diameter than the riser, which has the following effects:

[0031] 1. The inner diameter of the downcomer is increased to reduce the descending speed of the degassed molten steel, making it easier for the degassed molten steel to gather on the upper surface of the ladle (see Figure 2 It will not sink to the bottom of the ladle and mix with the non-degassed molten steel to participate in the circulation again, thereby reducing the number of degassed molten steel circulation times and improving the molten steel processing efficiency.

[0032] 2. Because the lower pipe opening of the riser is lower than the lower pipe opening of the downcomer, that is, the lower pipe opening of the riser is far away from the molten steel surface, the riser can only absorb the non-degassed molten steel at the bottom of the ladle, and the degassed molten steel enriched on the upper surface of the ladle will not be sucked again by the riser, so that the circulation of the molten steel is uniform and stable (that is, the riser absorbs the non-degassed molten steel at the bottom of the ladle, and the degassed molten steel discharged by the downcomer is accumulated on the upper surface of the ladle), and because the lower pipe opening of the riser is closer to the air-permeable brick, a larger lifting gas flow rate can be obtained, thereby increasing the circulation flow rate of the molten steel, thereby improving the rebar refining efficiency.

[0033] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0034] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An arrangement structure of asymmetric lift pipes in a RH refining furnace, characterized in that: include: A ladle (1) for containing molten steel, wherein a gas-permeable brick (2) is arranged at the bottom of the ladle (1); an RH furnace vacuum chamber (3), which is located above the ladle (1), and is provided with an ascending tube (4), a descending tube (5) and a vacuum chamber (301), one end of the ascending tube (4) and one end of the descending tube (5) respectively extending into the ladle (1), and the other ends thereof respectively communicating with the vacuum chamber (301); Wherein, the inner diameter of the downcomer (5) is larger than the inner diameter of the upcomer (4).

2. The arrangement structure of asymmetric lift pipes in a RH refining furnace according to claim 1, characterized in that: The inner diameter of the downcomer (5) is 1.4-1.5 times the inner diameter of the upcomer (4).

3. The arrangement structure of asymmetric lift pipes in a RH refining furnace according to claim 1, characterized in that: The lower pipe opening of the riser (4) extends downward and is arranged close to the air-permeable brick (2); the lower pipe opening of the downcomer (5) is arranged close to the steel liquid surface (6) and higher than the lower pipe opening of the riser (4).

4. The arrangement structure of asymmetric lift pipes in a RH refining furnace according to any one of claims 1 to 3, characterized in that: The air-permeable brick (2) is located directly below the lower pipe opening of the ascending pipe (4).

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