Патент USA US3463482код для вставки
Aug- 25, 1969 ‘ R. A. BUCHHOLZ 3,463,475 TAPHOLE CONSTRUCTION FOR METALLURGICAL VESSELS Filed April 21. 1967 w vavme RVSSELL 4. EUCIIHOLZ ITTOP/VE)" 1 United States Patent 0 ice 3,463,475 Patented Aug. 26, 1969 1 2 3,463,475 A further object of the invention is to provide a taphole conduit for a basic oxygen furnace composed entirely of TAPI-IOLE CONSTRUCTION FOR METALLURGICAL VESSELS pre?red, prefabricated refractory shapes. Russell A.‘ Buchholz, Pittsburgh, Pa., assignor to Dresser Industries, Inc., Dallas, Tex., a corporation of Delaware Filed Apr. 21, 1967, Ser. No. 632,688 Other objects of the invention, will in part, be apparent hereinafter. Int. Cl. C21b 7/12; C21c 5/50; F27b 7/00 US. Cl. 266-42 5 Claims of the invention, reference should be had to the following In order to more fully understand the nature and scope detailed description and drawings in which: FIG. 1 is a perspective view, partly broken away, of a ABSTRACT OF THE DISCLOSURE The present disclosure relates to improved taphole con 10 struction and taphole refractories for metallurgical vessels, for example, oxygen converter vessels. Particularly, the invention relates to a taphole fabricated from a plurality of prefabricated cylindrical conduit segments. Each seg ment has a substantially uniformly dimensioned molten metal passage of rectangular cross-sectional configuration, the longest surfaces of the passage being substantially in alignment with the vertical axis of the vessel. basic oxygen furnace, particularly showing the taphole side of the furnace; and FIG. 2 is a perspective view of a prefabricated taphole conduit for use in metallurgical vessels according to the present invention. :In accordance with the present invention and in attain ment of the foregoing objects, there is provided a metal lurgical vessel of the type having an outer metal support structure, a refractory lining interior of the support struc ture, a taphole opening passing through the lining and support structure and a taphole assembly passing through the taphole opening. The assembly is composed of a plurality of prefabricated, ceramically bonded cylindrical In the processing of molten steel, in furnaces such as conduit segments. Each segment includes a passage for the basic open hearth and the basic oxygen furnace, re molten metal between the end surfaces thereof. Further, fractories having a high degree of erosion resistance must 25 the opposed ends of the segments are preferably provided be employed in the metal contact areas. One such area of with complementary interlocking means, such as tongues and grooves, for mating with an adjacent segment. The these vessels, which is vulnerable to erosion is the tap hole of the vessel. The taphole of a metallurgical furnace molten metal passage is of substantially uniform dimen may be disposed in various locations depending on the sions and is rectangular in cross-sectional con?guration. furnace type. For example, in the basic open hearth, a 30 The longest surfaces of the con?guration are in align taphole is located below the molten metal bath, while in ment with the vertical axis of the vessel. The conduit segments are arranged in series and are complementarily the basic oxygen furnace, it is located above the metal mated. to provide an integral taphole assembly having a bath and the furnace is tilted to allow gravity ?ow of the continuous molten metal passage. molten metal through the taphole. In the formation of furnace tapholes, by prior practice, 35 a steel pipe, generally ranging from 2 to 6 feet in length was placed in the taphole area and an unconsolidated re fractory mix was rammed or cast around the pipe to hold The taphole conduit segments may be fabricated by methods well known in the art. One method includes form ing a stiff, mud-like mixture of selected refractory mate rial, vibration casting and then burning at a suitable tem perature to impart maximum strength. However, the most it in place. After the ?rst tapping of a furnace heat, the steel pipe would melt out and a completely refractory 40 economical and preferred method of fabrication is by mixing the selected refractory material with a tempering taphole would result. However, these tapholes are physi agent and ramming the mixture in a mold conforming to cally unsatisfactory for various reasons. The ramming and the contours of the conduit segments to obtain good casting mixes had to be, of course, placed in the furnace in densities upon subsequent burning. In either method, the an unburned state and thus could not attain the maximum density'and strength necessary to develop su?icient erosion 45 burning and ceramic bonding may be carried out after the segments are assembled into an integral unit, if the bum resistance necessary to satisfactorily survive a furnace ing kiln can accommodate the complete unit. An advantage heat. Further, the density and the strength of the tapholes of ?ring the segments before assembly is that the segments were non-uniform from end to end._ may be shipped to the job site where they are assembled It has been suggested to prefabricate a combination of without great risk of damage. castable and metal pipe. There has also been some sug The conduit segments may be composed of any basic gestion to employ prefabricated refractory sleeves to form refractory materials characterized by relatively good ero the tapholes. These sleeves had a circular molten metal sion resistance in contact with molten steel produced in passage which was found to be satisfactory for a period basic steelmaking furnaces. The preferred refractory mate of time. However, with ‘the rapidity that steel is now be ing produced especially in basic oxygen furnaces, i.e., 25 55 rials used in the furnaces mentioned are dead burned mag nesite and dolomite and mixtures thereof. Other basic re fractory materials having relatively good erosion resist— greater number of heats. The previously mentioned pre ance would also be satisfactory. These refractories may be fabricated tapholes, because of their circular molten metal tar impregnated and contain various other refractory in passages were found to erode quite rapidly along the side wall portion of the passageway with respect to the vertical 60 gredients known in the art to impart superior physical properties. A particularly useful refractory sleeve is com axis of the furnace. However, it has been discovered and posed of extremely refractory dead burned magnesite it is upon this that the invention is largely predicated that material of high purity periclase having a magnesia con taphole life can be increased by providing a molten metal tent of at least about 90%, by weight. passageway of rectangular cross-sectional con?guration wherein the longest surfaces of the rectangular con?gura 65 Referring to FIG. 1, there is shown a basic oxygen tion are in alignment with the vertical axis of the vessel. furnace 10, consisting of an outer metal shell 12, a shell Accordingly, it is an object of the present invention to protective lining 14 in contact with the inside surface of provide a means for fabricating a taphole for metallurgical the shell, and a brick working lining 16. The vessel is vessels consisting of preformed, pre?red refractory shapes. constructed of three major zones, the bottom zone 18, the Another object of the invention is to provide tapholes 70 barrel zone 20 and the cone section zone 22. The bottom for basic steelmaking furnaces that may be readily re zone is dish shaped and of upwardly opening concave placed between furnace heats. con?guration. The brick 23 in the bottom zone terminate heats in 24 hours, a taphole is needed that can survive a 3,463,475 3 4 at the barrel zone 20 with their face surfaces inclined from the bottom upwardly to the cone section zone. The working lining brick 14 in both the barrel and the cone section zones are disposed so that their face surfaces are in horizontal plane. The cone section zone, having a taphole area 26 extends upwardly and terminates in the form of a mouth 28 at the top of the vessel. The cone section zone is of downwardly opening truncated the segments so that the long surfaces thereof become the side walls of the metal passage, greater life is obtained with such a taphole than was obtained with previous taphole con?gurations. While the invention has been described in the drawings with reference to basic oxygen steelmaking vessels, it should not be limited thereto. Having thus described the invention in detail and with sui?cient particularity to enable those skilled in the art Disposed in the taphole area of the vessel is a taphole 10 to practice the invention, what is desired to have covered cross-sectional con?guration. by Letters Patent is set forth in the following claims: assembly 30 according to the present invention, which is composed of a plurality of identical conduit segments. An individual conduit segment is shown in FIG. 2. Each conduit segment 32 contains opposite ends which I claim: 1. 1n metallurgical vessels of the type having an outer metal support structure, a refractory lining interiorly adjacent the support structure and a taphole opening, are provided with a tongue 34 and a groove 36 for inter locking and mating with an adjacent segment in molten a taphole assembly passing through said taphole opening metal sealed relation. The conduit segments have gen erally opposed faces 38 and opposed sides 40. The op posed sides 40 contain a slight projection 42 for reasons that will be discussed subsequently. The molten metal composed of a plurality of prefabricated, ceramically bonded conduit segments having opposite ends, each segment having a substantially uniformly dimensioned passage is of rectangular cross'sectional con?guration having opposed long surfaces 44 and opposed short ?guration, the longest surfaces of said passage being in molten metal passage of rectangular cross-sectional con alignment with the vertical axis of the vessel, said conduit segments being complementarily mated to provide a surfaces 46. In practice, the taphole assembly of the prosent in continuous molten metal passage. 2. The vessel of claim 1 in which the opposite ends of the conduit segments are provided with interlocking vention can be placed in a basic oxygen vessel shown in FIG. 1, readily and with a minimum of labor. Gen erally, a refractory cement is not necessary at tongue and groove joints, since at the operating temperatures of the vessel the conduit segments will expand slightly means for mating with an adjacent segment. 3. The vessel of claim 2 in which the complementary interlocking means of the conduit segments consists of to provide a suf?cient seal. However, refractory cement 30 tongues and grooves. 4. The vessel of claim 1 in which the outer periphery may be employed, if desired, as an added safety factor or to facilitate installation. of the conduit segments is of rectangular cross-sectional con?guration. After the brick are stacked up to the cone section zone and the taphole opening, the ?rst conduit segment is laid on the refractory lining at the interior of the vessel. 5. The vessel of claim 1 in which the outer periphery of the conduit segments contain at least one projection The uppermost brick at the taphole opening are provided with slight depressions to accommodate the projections 42 extending therefrom for mating with adjacent refractory lining to hold it in place during installation in the taphole. on the conduit segments and hold them in place while the remainder of the segments are being added. Similarly, References Cited UNITED STATES PATENTS the lowermost brick extending down from the cone sec 40 tion zone contain depressions for the same purposes. 1,565,084 2,378,239 3,343,827 The remainder of the segments are then added by mating together the complementary tongues and grooves of a series of segments and securing them into a unit to pro vide a continuous molten metal passage. Each segment is laid so that the longest surface 44 of the metal passage is in substantial alignment with the vertical axis of the vessel. As was mentioned previously, it was found that when a heat is tapped, the greatest Frerichs __________ __ 266—42 Myron __________ __ 6l—11 X Hansen ________ __ 266—42 X FOREIGN PATENTS 45 1,111,224 7/1961 Germany. I. SPENCER OVERI-IOLSER, Primary Examiner amount of erosion in a taphole passage occurs at the side 50 266—36 walls. It was found that by forming a metal passage in a rectangular cross-sectional con?guration and arranging 12/1925 6/1945 9/1967 U.S. Cl. X.R.