The present invention relates to steel making, and in particular to a steelmaking taphole slag retardant device.
During the production of steel in a converter furnace, impurities, referred to as “slag”, float atop the molten metal. It is desirable to remove the molten metal from the furnace separately from as much of the slag as possible to minimize the amount of impurities within the metal. One conventional way of achieving that result is to tilt the furnace while plugging a tap hole of the furnace with a plug so as to block the exit of slag, and then the plug melts after at least most of the slag has passed thereover, whereby molten metal will be poured from the tap hole while the slag remains in the furnace.
It is desirable that the plug create an effective seal with the surface of the tap hole in order to minimize the leakage of slag past the plug. Also, it is desirable to install the plug deeply into the tap hole in order to minimize the amount of slag which can enter the tap hole. A plug must overcome certain formidable obstacles in order to achieve those goals.
The present invention, according to one aspect, is directed to a steel making assembly comprising a metal, refractory lined vessel having a side wall with a taphole therein and a metal plug within the taphole. The metal plug comprises a frustoconical body having a side conical wall, a closed small end and an open large end thereof defining an essentially empty interior space. The side conical wall of the frustoconical body of the plug includes at least one diagonal compression slit. The at least one diagonal compression slit extends from the open large end of the frustoconical body and extends toward the closed small end of the frustoconical body. The conical wall has a center axis, with the at least one diagonal compression slit being non-parallel to the center axis.
Another aspect of the present invention is to provide a plug configured for insertion into a taphole of a metal, refractory lined vessel during steel making. The plug comprises a metal frustoconical body having a side conical wall, a closed small end and an open large end thereof defining an essentially empty interior space. The side conical wall of the frustoconical body of the plug includes at least three diagonal compression slits. Each of the at least three diagonal compression slits extends from the open large end of the frustoconical body and extends toward the closed small end of the frustoconical body. The conical wall has a center axis, with each of the at least three diagonal compression slits being non-parallel to the center axis. Each of the at least three diagonal compression slits are curved.
Yet another aspect of the present invention is to provide a method of making steel comprising heating ore within a metal, refractory lined vessel to create molten steel and slag, with the metal, refractory lined vessel having a taphole. The method also includes providing a plug, with the plug comprising a metal frustoconical body having a side conical wall, a closed small end and an open large end thereof defining an essentially empty interior space. The side conical wall of the frustoconical body of the plug includes at least one diagonal compression slit. The at least one diagonal compression slit extends from the open large end of the frustoconical body and extends toward the closed small end of the frustoconical body. The conical wall having a center axis, with the at least one diagonal compression slit being non-parallel to the center axis. The method also includes inserting a plug into the taphole to close the taphole, tiling the metal, refractory lined vessel such that the slag passes the taphole and the molten steel covers the taphole and the plug, melting the plug after at least most of the slag passes the taphole, and removing the molten steel from the metal, refractory lined vessel through the taphole.
One or more embodiments of the present invention are illustrated by way of example and should not be construed as being limited to the specific embodiments depicted in the accompanying drawings, in which like reference numerals indicate similar elements.
The specific devices and processes illustrated in the attached drawings and described in the following specification are simply exemplary embodiments of the inventive concepts. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting.
For purposes of description herein, it is to be understood that the invention may assume various alternative orientations, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise.
The reference number 10 (
As shown in
As shown in
Many prior art plugs have been used in the prior art to plug the taphole 18. Examples are disclosed in U.S. Pat. No. 4,995,594 entitled SLAG STOPPING PLUG FOR TAP HOLES OF METAL FURNACES CONTAINING MOLTEN MATERIAL and U.S. Pat. No. 6,602,069 entitled PLUG MEMBERS FOR STEEL FURNACES, the entire contents of both of which are incorporated herein by reference. The prior art plugs have included rolled burlap, insulated refractory blankets, preformed refractory shapes, soft refractory shapes, as well as various metallic devices. Prior art plugs also include truncated cones open on the larger end. The plug 20 as described herein is an improved plug compared to the prior art plugs.
During use, the plug 20 is inserted into the taphole 18 of the metal, refractory lined vessel 10. While the plug 20 is being forced into the taphole 18 with the closed small end 26 entering the taphole 18 first, the side conical wall 24 will eventually encounter a side surface 32 (see
With use of the plug 20 as disclosed herein, the plug 20 significantly reduces the slag 16 from laying on top of the molten steel 14 within the holding vessel (e.g., a ladle) and after the molten steel 14 passes through the taphole 18 as described above. Furthermore, with use of the plug 20, the flow of the molten steel 14 through the taphole 18 can be better controlled by virtue of lowering the metal refractory lined vessel tapping angle thus enhancing the stream of molten steel 14 through the taphole 18 into a more laminar flow, thus reducing re-oxidation of the steel 14 and potentially improving the amount of steel 14 to fit within the holding vessel (e.g., a ladle). Furthermore, because of the diagonal compression slits 30, the plug 20 can be driven more deeply into the taphole 18 and closer to the hot face as compared to the prior art plugs, thereby reducing a length of taphole blockages or undesired solidification by steel 14 or slag 16, which could significantly reduce time spent burning open tapholes 18 which can cause costly delays in downstream processes.
The reference numeral 20a (
The illustrated plugs 20, 20a can have any appropriate dimensions in order to fully close the taphole 18 and can be made of any appropriate material to withstand the heat involved in the process of making steel. As to dimensions, an example is to have an open large end 28 that has a 5 inch diameter and a closed small end 26 that has a 3 inch diameter. In this example, the diagonal compression slits 30 can end within one inch of the closed small end 26. Nevertheless, any dimension to fit the taphole 18 can be used. As to material, any material can be used (e.g., mild steel).
Although particular preferred embodiments of the invention have been disclosed in detail for illustrative purposes, it will be recognized that variations or modifications of the disclosed apparatus, including the rearrangement of parts, lie within the scope of the present invention.
Number | Name | Date | Kind |
---|---|---|---|
4877221 | Scriven | Oct 1989 | A |
4995594 | Verbik | Feb 1991 | A |
5972281 | Stilkerieg | Oct 1999 | A |
6602069 | Purchase | Aug 2003 | B2 |
8591802 | Koffron | Nov 2013 | B2 |
Number | Date | Country | |
---|---|---|---|
20220349653 A1 | Nov 2022 | US |