Etching early warning device for dip pipe of RH furnace

Abstract

The utility model belongs to the technical field of ferrous metallurgy, and particularly relates to an RH furnace dip pipe etching early warning device which comprises a dip pipe and an early warning assembly, the dip pipe sequentially comprises a castable layer, a steel liner and a working layer refractory material from outside to inside, the early warning assembly comprises a guide pipe and a collision limiting switch, the guide pipe is located in the castable layer, and the collision limiting switch is located in the steel liner. A metal wire is arranged in the guide pipe, one end of the metal wire extends out of the guide pipe and then is connected with a blocking piece, the other end of the metal wire extends out of the guide pipe and then is connected with the collision limiting switch, and the portion, between the blocking piece and the collision limiting switch, of the metal wire is in a tensioned state. And the collision limit switch is interlocked with an RH emergency re-pressing system through an RH furnace control system. The pre-warning device can carry out accurate pre-warning when the steel liner of the dip pipe is etched by molten steel, and automatic re-pressing is linked, so that the slag suction phenomenon of a vacuum system of the RH furnace is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of iron and steel metallurgy, and particularly relates to an erosion warning device for an immersion tube of an RH furnace. Background Art

[0002] As the main smelting equipment in the refining process, the working principle of the RH furnace is to remove impurities and gases in the molten steel through vacuum suction and inert gas protection, so as to improve the quality and purity of the steel. The immersion tube in the RH furnace is located at the bottom of the vacuum tank and directly contacts the high-temperature molten steel during the steel smelting process, being in a harsh environment of continuous erosion by high-temperature steel slag. Therefore, higher requirements are imposed on its use safety factor.

[0003] Since the immersion tube is inserted into the molten steel during smelting, the abnormal changes in its state cannot be observed at all times during the smelting process. When the outer casting material of the immersion tube is severely eroded in the later stage of use, once the molten steel melts the steel bladder inside the casting material, the working refractory will fall off. In the lightest case, the immersion tube is scrapped and production is interrupted. In the most serious case, under the action of the vacuum in the vacuum tank and the external atmospheric pressure, if the immersion tube suddenly becomes shorter (due to the falling off of the working layer refractory), the balance between the molten steel in the vacuum tank and the molten steel in the ladle will be lost, and the molten steel and steel slag in the ladle will be instantly sucked into the vacuum system such as the vacuum tank and the cooling pipeline. At the same time, the top lance in the vacuum tank will be stuck by the steel slag, resulting in the serious consequence that it will be difficult to resume production in the vacuum system in a short time.

[0004] In the prior art, mainly the gunning method of the immersion tube is improved to extend the service life of the immersion tube, such as the method described in the patent document with the publication number CN107475486A. However, in the prior art, the erosion state of the immersion tube still needs to be observed and judged manually after one furnace of production of the immersion tube, and real-time monitoring during the smelting process cannot be achieved. When the immersion tube is in the later stage of use, the above-mentioned safety hazards still cannot be avoided. Content of the Utility Model

[0005] The purpose of the utility model is to provide an erosion warning device for an immersion tube of an RH furnace, which can monitor the erosion state of the immersion tube in real time during the smelting process, accurately warn of the occurrence of the phenomenon that the casting material is severely eroded and melts the steel bladder, and can also prevent the slag suction accident caused by the sudden shortening of the immersion tube, ensuring the safety of the vacuum system of the RH furnace.

[0006] The utility model adopts the following technical scheme:

[0007] An erosion warning device for an immersion tube of an RH furnace includes an immersion tube and a warning assembly.

[0008] The immersion tube comprises a casting material layer, a steel bladder and a working layer refractory from outside to inside.

[0009] The warning component includes a conduit and a collision limit switch. The conduit is located within the castable layer, extending from below the steel bladder along the outer wall of the steel bladder to the outside of the dipping tube. The collision limit switch is located outside the dipping tube.

[0010] A metal wire is provided inside the conduit. One end of the metal wire extends out of the conduit and is connected to a blocking member, and the other end of the metal wire extends out of the conduit and is connected to the collision limit switch. The metal wire between the blocking member and the collision limit switch is in a tensioned state.

[0011] The collision limit switch is interlocked with the RH emergency recompression system through the RH furnace control system.

[0012] Furthermore, the conduit winds around the outside of the lower opening of the steel bladder for more than one turn and then vertically extends out of the dipping tube from the upper opening of the steel bladder.

[0013] Furthermore, the collision limit switch is located above the dipping tube.

[0014] Furthermore, the metal wire is a copper wire.

[0015] Furthermore, the part of the conduit located outside the dipping tube is wrapped with asbestos.

[0016] Furthermore, the inner diameter of the conduit is 3 - 5 mm, and the wall thickness is 1 - 1.5 mm.

[0017] Furthermore, the conduit is welded to the outside of the steel bladder.

[0018] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0019] Through the settings of "placing the conduit within the castable layer, extending it from below the steel bladder along the outer wall of the steel bladder to the outside of the dipping tube, and arranging a metal wire inside the conduit" and "the metal wire tensioning the collision limit switch, and the collision limit switch being interlocked with the RH emergency recompression system through the RH furnace control system", first, based on the basic concept of using the high temperature of molten steel to melt the metal, the conduit is placed at the position outside and below the steel bladder, so that it can contact the molten steel earlier than the steel bladder. Second, by using the method that the melted and tensioned metal wire loosens the collision limit switch, it is possible to monitor the erosion condition of the dipping tube in the environment where the dipping tube is inserted into the molten steel and is not visible, and conduct monitoring and warning of the erosion condition of the dipping tube. Third, through the interlock between the collision limit switch and the RH emergency recompression system, it is possible to prevent serious slag suction accidents caused by the erosion of the dipping tube steel bladder, providing an important guarantee for the stable production of the RH furnace vacuum system.

[0020] The early warning device of the utility model is simple, practical and economical. It can give an accurate early warning when the molten steel corrodes the steel liner of the dipping tube, and is interlocked to automatically restore the pressure, avoiding the slag suction phenomenon of the vacuum system of the RH furnace and protecting the overall safety of the vacuum system. It solves the difficult risk problem in production in a simple way. Brief Description of the Drawings

[0021] Figure 1 It is a schematic diagram of the overall structure of the dipping tube erosion early warning device of the RH furnace of the utility model.

[0022] Among them, 1 - casting material layer, 2 - steel liner, 3 - working layer refractory, 4 - conduit, 5 - collision limit switch, 6 - metal wire, 7 - blocking piece. Specific Embodiments

[0023] Next, the technical solutions in the embodiments of the utility model will be clearly and completely described in conjunction with the drawings.

[0024] For the elaboration of the required spatial relationship, three orthogonal directions of "front and back", "left and right", and "up and down (or vertical)" can be defined, and a space rectangular coordinate system is defined through the relative position relationship.

[0025] Figure 1 Embodiment 1 of the utility model is shown.

[0026] Embodiment 1

[0027] Embodiment 1 discloses a dipping tube erosion early warning device for an RH furnace, including a dipping tube and an early warning component. The dipping tube sequentially includes a casting material layer 1, a steel liner 2, and a working layer refractory 3 from outside to inside.

[0028] The early warning component includes a conduit 4 and a collision limit switch 5. The conduit 4 is welded to the outside of the steel liner 2 inside the casting material layer 1, and the conduit 4 is wound around the outside of the lower opening of the steel liner 2 ( Figure 1 The opening at the top of the steel liner 2 is the upper opening, and the opening at the bottom is the lower opening) for more than one circle, and then extends out of the dipping tube along the outer wall of the steel liner 2 from the upper opening of the steel liner 2. During the actual smelting process of the dipping tube, it is generally eroded from the bottom up. Fixing the conduit 4 below the steel liner 2 can detect the erosion situation in time.

[0029] The collision limit switch 5 is located above the dipping tube. A metal wire 6 is arranged inside the conduit 4, and one end of the metal wire 6 extends out of the conduit 4 and is connected with a blocking piece 7. The outer diameter of the blocking piece 7 is larger than the inner diameter of the conduit 4. The other end of the metal wire 6 extends out of the conduit 4 and is connected with the collision limit switch 5. The metal wire 6 between the blocking piece 7 and the collision limit switch 5 is in a tensioned state. The metal wire 6 in this embodiment is a copper wire.

[0030] The part of the conduit 4 located outside the dipping tube is wrapped with asbestos to ensure that the conduit 4 outside the dipping tube is not deformed by the baking of molten steel and steel slag, resulting in leakage points, which will affect the judgment of the erosion situation.

[0031] The inner diameter of the conduit 4 is 3 - 5 mm, and the wall thickness is 1 - 1.5 mm.

[0032] The collision limit switch 5 is interlocked with the RH emergency recompression system through the RH furnace control system, so that when the metal wire 6 is melted and the collision limit switch 5 is closed, the RH emergency recompression system is started to automatically recompress, and the dipping tube is taken offline.

[0033] The installation and use process of the dipping tube erosion warning device of the RH furnace in this embodiment is as follows:

[0034] 1) After the refractory material of the working layer is installed on the steel liner of the dipping tube, the ramming material is filled and tamped between the steel liner and the refractory material of the working layer, and the conduit of the warning component is arranged: the conduit 4 is welded to the steel liner 2 of the dipping tube. Specifically, the conduit 4 is first wound around the outside of the lower opening of the steel liner 2 for more than one circle, and then extends vertically out of the dipping tube along the outer wall of the steel liner 2 from the upper opening of the steel liner 2.

[0035] 2) The metal wire 6 is passed through the conduit 4 arranged in step 1), and one end of the metal wire 6 near the lower opening of the steel liner 2 extends out of the conduit 4 and is fixedly connected to the blocking member 7.

[0036] 3) The casting layer 1 is built on the outside of the steel liner 2 of the dipping tube. After natural drying, the dipping tube is installed on the bottom of the vacuum tank, and the refractory materials in the circulation pipe and the vacuum tank are built. Then the metal wire 6 extending out of the conduit 4 is tightened and fixed on the collision limit switch 5 from above the dipping tube, and at the same time, the conduit 4 exposed outside the dipping tube is wrapped with asbestos to ensure that it is not deformed by the baking of molten steel and steel slag and no leakage points occur.

[0037] 4) After the vacuum tank is baked and put into operation for smelting molten steel, the collision limit switch 5 is interlocked with the RH furnace emergency recompression system through the RH furnace control system, and the collision limit switch 5 can transmit the collision limit information to the computer main operation interface of the RH furnace control system. When the metal wire 6 is in a tightened state, the collision limit switch 5 shows an open state. At this time, the dipping tube is in a state of not being severely eroded, and the RH furnace emergency recompression system does not work; when the refractory material of the casting layer below or on the side of the steel liner of the dipping tube (riser or downcomer) is severely eroded, and the molten steel melts through the conduit 2 and melts the metal wire 6 in the conduit 2, the metal wire 6 releases the collision limit switch 5. At this time, the collision limit switch 5 shows a closed state, and the RH furnace emergency recompression system is interlocked to start automatic recompression, that is, the vacuum tank is pressurized to make the molten steel in the vacuum tank return to the ladle, and the dipping tube is immediately taken offline.

Claims

1. An RH furnace immersion tube corrosion warning device, characterized in that: Including dip tube and warning assembly, The impregnation pipe is composed of a casting material layer, a steel liner and a working layer refractory material from the outside to the inside. The early warning component includes a conduit and a collision limit switch. The conduit is located in the casting material layer and extends from the bottom of the steel liner along the outer wall of the steel liner to the outside of the immersion tube. The collision limit switch is located outside the immersion tube. A metal wire is arranged in the conduit, and one end of the metal wire is connected to a blocking member after extending out of the conduit, and the other end of the metal wire is connected to a collision limit switch after extending out of the conduit, and the metal wire between the blocking member and the collision limit switch is in a tensioned state. The collision limit switch is interlocked with the RH emergency re-pressurization system through the RH furnace control system.

2. The RH furnace immersion tube corrosion warning device according to claim 1 is characterized in that: The conduit is wound around the outer side of the lower opening of the steel bladder for more than one circle, and then a dipping pipe is vertically extended from the upper opening of the steel bladder.

3. The RH furnace immersion tube corrosion warning device according to claim 2, characterized in that: The collision limit switch is located above the immersion pipe.

4. The RH furnace immersion tube corrosion warning device according to claim 1, characterized in that: The metal wire is a copper wire.

5. The RH furnace immersion tube corrosion warning device according to claim 1 or 2, characterized in that: The portion of the conduit located outside the impregnated tube is wrapped with asbestos.

6. The RH furnace immersion tube corrosion warning device according to claim 1, characterized in that: The inner diameter of the catheter is 3 to 5 mm, and the wall thickness is 1 to 1.5 mm.

7. The RH furnace immersion tube corrosion warning device according to claim 1, characterized in that: The conduit is welded to the outside of the steel bladder.

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