Arc-shaped furnace nozzle structure of induction furnace and tapping method for shortening tapping stroke of arc-shaped furnace nozzle structure

Abstract

The invention discloses an arc-shaped furnace nozzle structure of an induction furnace and a tapping method for shortening the tapping stroke of the arc-shaped furnace nozzle structure, and belongs to the technical field of metallurgical smelting equipment. Comprising a furnace nozzle body arranged at a tapping hole of the induction furnace; the furnace nozzle lining is arranged in the middle of the furnace nozzle body and used for forming a furnace nozzle runner for melt to flow; the furnace mouth front end flow guide part is positioned at the outlet end of the furnace mouth body; a transition section between the appearance of the flow guide part and the outlet of the furnace nozzle runner is an arc transition surface, so that a melt forms a streamline with continuous curvature transition in the tapping direction; the front end of the furnace nozzle is transformed into the arc-shaped flow guide end from a traditional straight end face structure, so that a continuous curvature transition streamline is formed in the tapping process of a melt, the effective tapping stroke and the exposure length of a runner of the furnace nozzle are shortened, the heat dissipation and flow blocking risk of the melt at the tapping section is reduced, temperature drop, slag adhering and nodulation and flow fluctuation are reduced, and the service life of the furnace nozzle is prolonged. And stable, low-resistance and low-temperature drop tapping is realized. The structure is suitable for induction melting scenes such as a vacuum induction furnace.

Description

Technical Field

[0001] This invention relates to the field of metallurgical smelting equipment and steel tapping technology, specifically to an arc-shaped furnace nozzle structure for an induction furnace and a steel tapping method that shortens the tapping stroke. Background Technology

[0002] Induction furnace tapping typically relies on a nozzle to guide the molten steel from the furnace body to the ladle, die, or runner system. Existing nozzles often have a flat end face or a zigzag transition structure, which can easily lead to the following problems in actual production: (1) Long tapping stroke and long exposed section: The molten metal is exposed to the environment for a longer time at the tapping end, resulting in a greater temperature drop; (2) Coupling of temperature drop and resistance: The increase in temperature drop causes the melt viscosity to rise and the nodule to form faster, which further aggravates the resistance and forms a vicious cycle; (3) High maintenance costs: Frequent cleaning of the nozzle end shortens its lifespan, affecting production cycle and quality stability.

[0003] Therefore, there is an urgent need for a furnace nozzle structure modification scheme that can shorten the tapping stroke, reduce temperature drop, and reduce the risk of obstruction. Summary of the Invention

[0004] The purpose of this invention is to provide an arc-shaped nozzle structure for an induction furnace and a method for shortening the tapping stroke. This involves setting an arc-shaped transition surface at the front end of the nozzle and a tapering section at the tapping opening. The nozzle body is made of high-alumina, magnesia, spinel, zircon, or composite refractory materials, and its inner surface can be coated with an anti-wetting and / or anti-adhesion coating. Simultaneously, by coordinating nozzle preheating, tapping angle, and tapping height control, the molten metal forms a continuous curvature transition streamline during tapping, thereby reducing flow resistance and temperature drop, thus solving the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: an arc-shaped nozzle structure for an induction furnace, comprising: The furnace nozzle body is located at the tapping port of the induction furnace. The nozzle liner is located in the middle of the nozzle body to form a nozzle flow channel for the flow of melt; The flow guide at the front end of the nozzle is located at the outlet end of the nozzle body; The shape of the guide section and the outlet transition section of the furnace nozzle flow channel are arc transition surfaces, so that the melt forms a continuous curvature transition streamline in the steel tapping direction, thereby reducing the effective stroke of the steel tapping section and reducing flow resistance and temperature drop.

[0006] Preferably, the radius R of the arc transition surface is 30 to 200 mm.

[0007] Preferably, the furnace nozzle lining is provided with a tapered section near the taper opening, with a taper angle α of 2° to 12°.

[0008] Preferably, the burner nozzle body material is a high-alumina, magnesium, spinel, zircon, or a composite refractory material thereof, and an anti-wetting and / or anti-adhesion coating may be applied to the inner surface.

[0009] A method for shortening the tapping stroke using an arc-shaped furnace nozzle structure in an induction furnace includes the following steps: S1. Burner preheating: Preheat the burner body to the set temperature range; S2. Steel tapping start: Activate the steel tapping mechanism to allow the molten metal to enter the furnace nozzle flow channel; S3. Arc guiding: The melt continuously turns through the arc transition surface and is discharged from the outlet, shortening the effective stroke of the outlet section; S4. Stable tapping: By controlling the tapping angle, tapping height and receiving position, the free fall of the melt and the exposed length are minimized.

[0010] Preferably, in S4, the effective exposed stroke from the steel outlet to the receiving position is reduced by 10% to 40% compared to before the modification, so as to reduce the risk of temperature drop and obstruction.

[0011] Compared with the prior art, the beneficial effects of the present invention are: (1) Shortened stroke: The arc guide reduces the effective exposed section at the tapping end, making the exposed length of the melt shorter; (2) Reduced temperature drop: The exposed section is shortened and the flow is more stable, which helps to reduce heat dissipation in the steel tapping section and reduce the temperature drop to the ladle and die ends; (3) Reduced risk of obstruction: Continuous curvature transition helps to reduce eddies and adhesion at the turning point, and reduces the tendency of flow channel narrowing and blockage caused by slag and nodule formation; (4) Improved maintainability: The rate of nodule formation at the nozzle tip is reduced, which helps to extend the cleaning and replacement cycle. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of an existing straight-faced burner nozzle structure; Figure 2 This is a schematic diagram of the arc-shaped nozzle structure of the present invention; Figure 3 A schematic diagram showing the formation of lumps on the burner nozzle. Figure 4 This is a schematic diagram showing the completion of pouring for the arc-shaped furnace nozzle.

[0013] In the diagram: 1. Burner body; 2. Burner liner; 3. Flow guide. Detailed Implementation

[0014] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0015] Please see Figure 1-4 The present invention provides a technical solution: Example 1 The front guide section of the nozzle is machined into a rounded transition surface with a radius of R=130mm; The steel taper is designed with a tapered section and a taper angle α = 6°. Before tapping, preheat the tip of the furnace nozzle to the set temperature range (as set by the on-site process).

[0016] Effect Description: Compared to before the modification, the exposed stroke at the tapping end is shortened, the fluctuation during the tapping process is reduced, the temperature drop at the receiving end is decreased, and the rate of slag formation and nodule buildup at the furnace nozzle end is reduced. Figure 4 As shown.

[0017] Example 2 The front guide section of the nozzle is machined into a rounded transition surface with a radius of R=100mm; The inner surface of the burner nozzle is coated with an anti-wetting coating.

[0018] Before tapping, preheat the tip of the furnace nozzle to the set temperature range (as set by the on-site process).

[0019] Effect description: The arc radius nozzle and anti-wetting coating can reduce the tendency of melt adhesion and obstruction, and reduce the probability of wall adhesion and nodule formation.

[0020] Example 3 The front guide section of the nozzle is machined into a rounded transition surface with a radius of R=120mm; The inner lining is made of high-alumina refractory material, and the inner surface is polished to Ra≤12.5μm; Before tapping, preheat the tip of the furnace nozzle to the set temperature range (as set by the on-site process).

[0021] Effect description: The combination of the arc radius nozzle and high-alumina refractory material with low roughness can reduce the tendency of melt adhesion and obstruction, and decrease the probability of wall adhesion and nodule formation.

[0022] Comparative Example 1 Keep the front end of the furnace nozzle flat, and keep other process conditions as consistent as possible.

[0023] Comparative observations: Longer exposed stroke, more significant temperature drop; more prone to slag and nodule formation at end bends, greater tapping fluctuations, and higher maintenance frequency. Nodule formation is as follows... Figure 3 As shown.

[0024] In the description of this invention, it should be understood that the terms "coaxial," "bottom," "one end," "top," "middle," "other end," "upper," "side," "top," "inner," "front," "center," "both ends," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0025] Furthermore, the terms “first,” “second,” “third,” and “fourth” are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as “first,” “second,” “third,” or “fourth” may explicitly or implicitly include at least one of those features.

[0026] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "setting," "connection," "fixing," "screw connection," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components or the interaction between two components. Unless otherwise explicitly limited, those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0027] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An arc-shaped burner nozzle structure for an induction furnace, characterized in that: include: The furnace nozzle body (1) is located at the outlet of the induction furnace; The nozzle liner (2) is located in the middle of the nozzle body (1) to form a nozzle flow channel for the flow of melt; It is placed in the flow guide section (3) at the front end of the nozzle, located at the outlet end of the nozzle body (1); The guide section (3) has a circular arc transition surface with the outlet transition section of the furnace nozzle flow channel, so that the melt forms a continuous curvature transition flow line in the steel tapping direction, thereby reducing the effective stroke of the steel tapping section and reducing flow resistance and temperature drop.

2. The arc-shaped burner nozzle structure of an induction furnace according to claim 1, characterized in that: The radius R of the arc transition surface is 30 to 200 mm.

3. The arc-shaped burner nozzle structure of an induction furnace according to claim 1, characterized in that: The furnace nozzle lining (2) is provided with a tapered section near the steel outlet, and its taper angle α is 2° to 12°.

4. The arc-shaped burner nozzle structure of an induction furnace according to claim 1 is characterized in that: The material of the burner body (1) is high alumina, magnesium, spinel, zircon or its composite refractory material, and the inner surface may be coated with an anti-wetting and / or anti-adhesion coating.

5. A method for shortening the tapping stroke using an arc-shaped furnace nozzle structure in an induction furnace according to any one of claims 1-4, characterized in that: Includes the following steps: S1. Burner preheating: Preheat the burner body to the set temperature range; S2. Steel tapping start: Activate the steel tapping mechanism to allow the molten metal to enter the furnace nozzle flow channel; S3. Arc guiding: The melt continuously turns through the arc transition surface and is discharged from the outlet, shortening the effective stroke of the outlet section; S4. Stable tapping: By controlling the tapping angle, tapping height and receiving position, the free fall of the melt and the exposed length are minimized.

6. The steel tapping method for shortening the tapping stroke using an arc-shaped furnace nozzle structure in an induction furnace according to claim 1, characterized in that: In S4, the effective exposed stroke from the steel outlet to the receiving position is reduced by 10% to 40% compared to before the modification, in order to reduce the risk of temperature drop and obstruction.

Images