Gas protection device matched with molten steel pouring

Abstract

The utility model relates to a gas protection device matched with molten steel pouring. An annular air pipe is additionally arranged on the periphery of a molten steel flowing nozzle in a traditional molten steel pouring system and communicated with an inert gas pipeline, a plurality of downward air holes are formed in the pipe wall of the air pipe, inert gas is sprayed out of the air holes, an inert gas cylindrical air film is formed, and air on the periphery of the molten steel flowing nozzle is isolated from molten steel. A two-position three-way valve is arranged on an inert gas pipeline, a passage of the two-position three-way valve is switched through linkage of a handle and a lower sliding plate, and the inert gas pipeline is communicated with the annular gas pipe when molten steel is injected, so that a cylindrical gas protection film is formed; and when pouring is suspended, the inert gas pipeline is communicated with the grate steel meshes to form an air cushion to prevent the molten steel from being cooled and solidified in the molten steel channel. Molten steel can smoothly flow out of the steel ladle, and the molten steel is prevented from being polluted by air in the flowing process.

Description

Technical Field

[0001] The utility model relates to a gas protection device, in particular to a gas protection device for preventing secondary contamination of molten steel during the molten steel pouring process, and belongs to the technical field of metal casting. Background Art

[0002] During the pouring process, molten steel flows from the ladle, flows downward a certain distance, enters the pouring cup, and then flows through the steel flow channel and the outlet of the steel flow brick into the mold. Because the molten steel comes into direct contact with air, it may introduce air into the mold. Secondary contamination of the molten steel by air can have many adverse effects on castings, leading to an increase in impurities in the steel. In particular, the entry of air into the molten steel significantly increases the hydrogen content in the steel, disrupting the steel's continuity and reducing its mechanical properties such as strength, toughness, and plasticity. When subjected to stress, stress concentration is easily generated around the impurities, forming cracks and reducing the service life of the steel. Therefore, it is necessary to optimize processes and improve equipment to reduce the impact of secondary contamination on steel quality. Summary of the Invention

[0003] Aiming at the technical deficiencies of the traditional molten steel pouring system, the utility model provides a gas protection device for molten steel pouring. An annular inert air flow curtain and a linked reversing valve are added to the molten steel pouring system to ensure that the molten steel flows out of the ladle smoothly and to prevent the molten steel from being contaminated by air during the flow.

[0004] In order to achieve the above-mentioned purpose, the utility model adopts the following technical solutions: a gas protection device for molten steel pouring, comprising: a ladle and a steel pouring system, wherein the steel pouring system comprises: an upper slide, a lower slide, an inert gas pipeline, a pouring cup, a steel flow channel and a mold, wherein the upper slide is fixed to the bottom surface of the ladle and forms a moving pair with the lower slide; steel flow holes are respectively provided on the bottom of the ladle and the upper slide, and a grate steel mesh and a steel flow nozzle are provided on the lower slide, wherein the grate steel mesh is connected to the connecting port of the inert gas pipeline; When the slide moves to the right to the set limit position, the steel flow holes on the bottom of the ladle and the upper slide are connected to the grate steel mesh holes on the lower slide to form an air injection channel, and inert gas is sprayed into the steel flow holes on the upper slide. When it moves to the left to the set limit position, the steel flow holes on the bottom of the ladle and the upper slide are connected to the steel flow outlet on the lower slide to form a molten steel channel. The steel flow outlet on the lower slide is opposite to the pouring cup, and the molten steel is injected into the mold through the steel flow channel. A splash guard is provided between the lower slide and the pouring cup, and the steel flow outlet passes downward through the splash guard. It is characterized in that:

[0005] An annular air pipe is provided above the anti-splash baffle, the annular air pipe is closely attached to the anti-splash baffle, and a plurality of downward air holes are provided on the pipe wall;

[0006] The splash guard is provided with a ventilation net;

[0007] A two-position three-way valve is provided on the inert gas pipeline, and its valve core is linked to the lower slide. When the lower slide moves to the right to the set limit position, the pressure air inlet of the valve is connected to the grate steel mesh. When it moves to the left to the set limit position, the pressure air inlet of the valve is connected to the annular air pipe.

[0008] Preferably, the pores have a diameter greater than 0.3 mm and less than 1 mm.

[0009] Preferably, the working pressure of the inert gas is set at 0.15-0.25 MPa.

[0010] Furthermore, the inner cross-sectional area of the annular air tube is greater than 1.3 times the total cross-sectional area of the plurality of air holes.

[0011] Furthermore, the annular diameter of the annular air pipe is set to 1.2-1.5 times the diameter of the pouring cup.

[0012] The utility model adds an annular air pipe to the traditional steel pouring system, and adds a two-position three-way valve to the inert gas pipeline, which is linked to the lower slide to switch the passage. When pouring molten steel, the inert gas pipeline is connected to the annular air pipe. The inert gas in the annular air pipe is ejected from the air holes, passes through the ventilation mesh on the splash guard, and forms a cylindrical inert gas film around the outer edge of the molten steel column, isolating the air from the molten steel. When pouring is suspended, the inert gas pipeline is connected to the mesh of the grate steel, forming an air cushion to prevent the molten steel from cooling and solidifying in the molten steel channel, ensuring that the molten steel flows smoothly out of the ladle and avoiding air contamination during the flow of the molten steel. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Attachment Figure 1 This is a schematic diagram of the utility model in which the molten steel channel is disconnected.

[0014] Attachment Figure 2 This is a schematic diagram of the utility model in the state of molten steel channel being connected.

[0015] Attachment Figure 3 For attachment Figure 1 The enlarged diagram of the structure of part I,

[0016] Attachment Figure 4 For attachment Figure 2 The enlarged diagram of the structure of part II,

[0017] Attachment Figure 5 For attachment Figure 3 A-direction structure enlarged diagram,

[0018] Attachment Figure 6 For attachment Figure 5 Schematic diagram of the cross-sectional structure of the middle BB section.

[0019] In the accompanying drawings, 1 is a ladle, 2 is molten steel, 3 is a steel pouring system, 4 is a pouring cup, 5 is a steel flow channel, 6 is a mold, 301 is an upper slide, 302 is a lower slide, 303 is a handle, 304 is a connecting rod, 305 is a two-position three-way valve, 306 is an annular air pipe, 307 is a cylindrical air film, 308 is an air hole, 309 is a splash guard, 310 is a ventilation net, a and b are inert gas pipelines, c and d are steel flow holes, e is a grate steel mesh hole, f is a molten steel flow outlet, and p is a pressure air inlet. DETAILED DESCRIPTION

[0020] The present invention will be further explained below with reference to the accompanying drawings;

[0021] As attached Figure 1 、 2 As shown in Figures 3 and 4, the steel pouring system 3 includes: an upper slide 301, a lower slide 302, inert gas pipelines a and b, a pouring cup 4, a steel flow channel 5 and a mold 6. The upper slide 301 is fixed to the bottom surface of the ladle 1 and forms a moving pair with the lower slide 302; the bottom of the ladle 1 and the upper slide 301 are respectively provided with steel flow holes c and d, the lower slide is provided with a grate steel mesh e and a steel flow nozzle f, and a splash guard is provided between the lower slide 302 and the pouring cup 4. Plate 309, the molten steel flow outlet f passes downward through the splash baffle 309, the annular air pipe 306 is closely attached to the splash baffle 309, and a number of downward air holes 308 are provided on its wall; a ventilation net 310 is provided on the splash baffle 309, and a two-position three-way valve 305 is provided on the inert gas pipeline, whose valve core is linked to the lower slide plate 302, and the pressure air inlet p of the valve is connected to the grate steel mesh e on one way, and is connected to the annular air pipe 306 on the other way.

[0022] As attached Figure 1 、 3 As shown, the external force connecting rod 304 drives the lower slide 302 to slide on the bottom surface of the upper slide seat 301 to the right limit setting position, the steel flow hole c and the grate steel mesh e are opposite, and at the same time drives the handle 303 to switch the two-position three-way valve pressure inlet p to connect with the inert gas pipeline a and disconnect it from the inert gas pipeline b. The inert gas is sprayed into the ladle 1 with a certain pressure through the grate steel mesh e, the steel flow hole c and d, so that the molten steel 2 above the steel flow hole c is suspended in the ladle 1, thereby preventing the molten steel 2 from solidifying in the molten steel channel c.

[0023] As attached Figure 2 、 4As shown, the external force connecting rod 304 drives the lower slide 302 to slide on the bottom surface of the upper slide 301 to the left limit setting position, and the steel flow holes c and d are connected to the steel water flow outlet f. At the same time, it drives the handle 303 to switch the two-position three-way valve air inlet p to be connected to the inert gas pipeline b. The molten steel 2 in the ladle 1 flows out through the steel flow holes c and d and the steel water flow outlet f to form a molten steel column. The molten steel column enters the pouring cup 4 and then enters the mold 6 through the steel flow channel 5. At the same time, the inert gas in the annular air pipe 306 is ejected through the air hole 308 and the ventilation net 310 on the splash guard 309, forming a cylindrical air film 307 on the periphery of the molten steel column to isolate the molten steel column from the air.

[0024] Attachment Figure 5 、 6 The structure, shape and positional relationship of the annular air pipe 306, the air hole 308, the splash guard 309, the ventilation net 310 and the water inlet f are shown.

Claims

1. A gas protection device for molten steel pouring, comprising: The ladle and steel pouring system, the steel pouring system includes: an upper slide, a lower slide, an inert gas pipeline, a pouring cup, a steel flow channel and a mold, the upper slide is fixed to the bottom of the ladle and forms a moving pair with the lower slide; the bottom of the ladle and the upper slide are respectively provided with steel flow holes, the lower slide is provided with grate steel mesh and steel flow nozzle, the grate steel mesh is connected to the connecting port of the inert gas pipeline; when the lower slide moves to the right to the set limit position, ... steel flow holes, the lower slide is provided with steel flow nozzle, the lower slide is provided with steel flow nozzle, the lower slide is provided with steel flow nozzle, the lower The steel flow holes are connected with the grate steel mesh holes on the lower slide to form an air injection channel, and inert gas is sprayed into the steel flow holes on the upper slide. When the ladle moves to the left to the set limit position, the steel flow holes on the bottom of the ladle and the upper slide are connected with the steel flow inlet on the lower slide to form a steel flow channel. The steel flow inlet on the lower slide is opposite to the pouring cup, and the molten steel is injected into the mold through the steel flow channel. A splash guard is set between the lower slide and the pouring cup, and the steel flow inlet passes downward through the splash guard. It is characterized in that: An annular air pipe is provided above the anti-splash baffle, the annular air pipe is closely attached to the anti-splash baffle, and a plurality of downward air holes are provided on the pipe wall; The splash guard is provided with a ventilation net; A two-position three-way valve is provided on the inert gas pipeline, and its valve core is linked to the lower slide. When the lower slide moves to the right to the set limit position, the pressure air inlet of the valve is connected to the grate steel mesh. When it moves to the left to the set limit position, the pressure air inlet of the valve is connected to the annular air pipe.

2. A gas protection device for molten steel pouring according to claim 1, characterized in that: The pores have a diameter greater than 0.3 mm and less than 1 mm.

3. The gas protection device for molten steel pouring according to claim 1 is characterized in that: The inner cross-sectional area of the annular trachea is greater than 1.3 times the total cross-sectional area of the plurality of pores.

4. A gas protection device for molten steel pouring according to claim 1, characterized in that: The working pressure of the inert gas is set between 0.15 and 0.25 MPa.

5. The gas protection device for molten steel pouring according to claim 1 is characterized in that: The annular diameter of the annular air pipe is 1.2 to 1.5 times the diameter of the pouring cup.

Images