FIELD TIP ASSEMBLY FOR MANUFACTURING METALS FIELD OF THE INVENTION The present invention relates in general to the equipment for the manufacture of metals and in particular to lances for the manufacture of metals. BACKGROUND OF THE INVENTION In many metal fabrication processes, water-cooled lances are inserted into a furnace vessel to carry out the desired metal processing functions. For example, in steelmaking processes, a water-cooled lance is inserted into a steelmaking vessel (eg, a basic oxygen furnace (BOF), an electric arc furnace (EAF), etc.), to promote fusion, decarburization, refining and other useful processes for converting iron-containing scrap into steel into the container. A typical lance can inject gaseous materials such as oxygen, hydrocarbon gases and / or inert gases at high speed at various times, to achieve the desired treatment of the loaded material (scrap and hot metal) and / or maintenance of the interior of the container. Some lances can also inject carbon and / or lime particles (or other substances) to achieve the desired properties in the steel produced at the end.
The water-cooled lances generally comprise an adapter portion, a flared drum portion connected at a first end thereof to the adapter portion and a tip portion of the lance connected to a second end of the drum portion. The adapter portion comprises at least one intake for receiving the gaseous materials and / or in particular to be injected into the oven container, which materials will be referred to hereinafter as "active materials" in general. The adapter portion also includes a water inlet and a water discharge to circulate pressurized cooling water through the lance. The drum portion comprises at least three metals arranged in a substantially concentric manner, typically steel, tubes for communicating the cooling water and / or the active material or materials between the adapter portion and the tip portion of the lance, the outermost tubes and innermost normally define an annular water return passage for transporting the cooling water from the tip portion of the lance to the adapter portion. The first and second innermost tubes normally define an annular water supply passage for transporting the cooling water to the tip portion of the lance from the adapter portion. And, the interior of the second innermost tube (and all additional tubes disposed therein) define at least one passage for transporting the active materials from the adapter portion to the tip of the lance for injection into the interior of the oven container . The tip portion of the lance comprises an assembly having one or more parts which can be secured by welding or the like to the concentric tubes of the drum portion. The tip assembly of the lance comprises at least one nozzle in communication with the at least one passage of active materials from the drum portion for injecting or discharging the active materials into the interior of the oven container. The tip assembly further comprises means of channeling means for connecting the water supply and the return passages of the drum portion together. Thus constructed, the water or other cooling fluid can be circulated continuously through the lance to cool the lance, especially the tip assembly of the lance, which is exposed to the higher temperatures during the operation of the lance. Of course, if the coolant water is not effectively transported through the tip portion of the lance then the assembly may not heat evenly. This, in turn, can lead to the so-called "points hot "or" continuous burn "sites, which often result in premature failure of the spear tip, a common practice whereby the steel making industry has sought to impart cooling to the spike assemblies The purpose of such a protrusion is to direct the cooling water radially outwardly through the interior space of the spout, the purpose of which is to provide a protrusion or dent generally disposed centrally on the inner surface of the tip face member of the spike assembly. tip of the spear, to cool all areas of the face of the external work surface of the spear tip. The protrusions that deflect the water have assumed a variety of sizes and shapes and have obtained varying degrees of success for their intended purposes. Examples of such protuberances can be found in U.S. Patent Nos. 3,224,749; 3,525,508; 3,525,509; 3,823,929; 3,827,632; 4,083,539; 4,083,541; 4,083,542; 4,083,543; 4,083,544; 4,106,756; 4,322,033; 4,432,534; 4,702,462; 4,951,928; 6,234,406 and the republication of the American Patent No. 28,769, as well as the Patents of the United Kingdom Nos. 1,190,137 and 1,255,082. U.S. Patent No. 4,417,721 proposes an alternative means for improving the flow of cooling water through the inner surface of a spearhead. In particular, a plurality of intrinsically shaped radial water flow passages are provided between a lower surface of a cooling water baffle member and the inner surface of the face member of the lance tip. The radial flow passages are defined and located between flow blades of uniform thickness. U.S. Patent Nos. 3,322,419 and 3,337,203 and U.S. Patent No. 1,255,982 combine a centrally disposed protuberance and a plurality of coolant flow vanes disposed radially on the inner surface of the face member of the spear tip. However, in each of these designs, the vanes do not extend (1) either essentially to the axial distance or the full height between the inner surface of the face member of the spear tip and the lower surface of the deflector member of the refrigerant flow or (2) essentially at the full radial distance from the central protrusion to the annular return passage of the cooling fluid. Radial or axial coolant flow slots considerable in these designs allow cross flow between the adjacent coolant flow passages on the inner surface of the face member of the spear tip.
It is believed that such cross-flow produces spiral currents and dead spaces in the flow of cooling water which could result in the formation of hot spots on the external work surface of the face member of the spear tip. There is an advantage, therefore, to a metal-tipped lance assembly which is comparatively easy to assemble and durable and which provides a substantially uniform cooling of the working face of the lancet head through of structural characteristics that promote an intense flow and speed of the cooling water through the tip.
There is an additional advantage for a spearhead assembly for metal fabrication that has a structurally reinforced face for improved operating performance and service life. BRIEF DESCRIPTION OF THE INVENTION The present invention provides a lance tip assembly for a water-cooled lance. In general, the assembly includes a tip face member having a plurality of outlets, a plurality of nozzles corresponding in number and in communication with the outlets of the tip face member and with a corresponding number of inputs provided in a active material well member, a refrigerant deflector member for directing the flow of refrigerant around the nozzles, and a support post of the tip face member connecting the tip face member and the well member of active materials to provide structural support to the tip face member during the operation of the lance. Unlike other spearhead assemblies, the spear head assembly of the present invention further includes both a centrally disposed deviating coolant boss and a plurality of radial vanes on the inner surface of the tip face member, which vanes extend essentially over the entire axial distance between the inner surface of the face member of the lance tip and the lower surface the deflector member of the flow of the cooling fluid and essentially over the entire distance from the protrusion to the annular passage of the cooling fluid. return of the refrigerant fluid. The resulting construction provides high velocity and a flow of the cooling fluid essentially free of vortices and voids through the entire surface of the face member of the spear tip, which, in turn, cools the face member uniformly. the spearhead and greatly improves the service life of the spearhead assembly. Other details, objects and advantages of the present invention will become apparent when they come from the following description of the currently preferred embodiments and currently preferred methods for practicing the invention. BRIEF DESCRIPTION OF THE DRAWINGS The invention will become readily apparent from the following description of the preferred embodiments thereof shown by way of example only, in the accompanying drawings, in which: FIG. 1 is a cross-sectional elevation view of a spear head assembly according to the present invention, taken along line I-I of FIG. 2; FIG. 2 is a view of the working face of the spear head assembly of FIG. 1; FIG. 3 is a cross-sectional elevation view of the lance tip assembly shown attached to the lower end of the drum portion of a metal fabrication lance; FIG. 4 is a planar view of the inner surface of the tip face member of the lance tip assembly;
FIG. 5 is an elevational cross-sectional view of the tip face member taken along the line V-V of FIG. 4; FIG. 6 is an elevational cross-sectional view of the tip face member taken along the line VIVI of FIG. 5 and illustrating a preferred cooling reinforcement relationship for coolant vanes constructed in accordance with the present invention; and FIG. 7 is an elevational cross-sectional view of a central portion of the tip face member according to the present invention, illustrating a dent profile relationship for a central gap provided therein. DETAILED DESCRIPTION OF THE INVENTION Referring to the drawings in which identical or similar references indicate identical or similar elements in the various views, it is collectively shown in FIGS. 1-3, a lance tip assembly for metal fabrication according to the present invention, which is generally identified by the reference number 10. The assembly 10 preferably comprises: a tip face member 12 which has a plurality of outlet 14, a plurality of outwardly diverging nozzles 16 corresponding in number and in communication with the outlets 14 of the tip face member and with a corresponding number of inlets 18 provided in a well member 20 of materials active, a coolant deflector member 22 for directing the flow of refrigerant around the nozzles 16, and a support post 24 for the tip face member connecting the tip face member 12 and the bore member 20 active materials to provide structural support to the tip face member during the operation of the lance. The example illustrated in FIG. 2 represents four nozzles that are arranged equidistantly about the central longitudinal axis 26 of the assembly 10. However, any desired number of nozzles in any desired orientation can be provided in the assembly. As known, the nozzles 16 allow the gaseous and / or particulate materials to pass from a flow space of the active material, described below, through the corresponding outlets 14 and into the interior of a non-illustrated oven container, such as, for example, a container for steel manufacture. An exemplary, but not limiting, procedure for assembling the spearhead assembly 10 is as follows. The various components of the assembly 10 can be made of metal or metal alloys including, without limitation, copper, bronze, steel, stainless steel, and the like, as may be appropriate for the intended function (s) or the desired characteristic (s) of the components (for example, structural strength, thermal conductivity, etc.).
One end of the support post is welded to the uppermost portion of a protrusion 28 located centrally on the inner surface 30 of the tip face member 12. The protrusion 28 is described in detail in connection with the discussion of FIG. 5. The tip face member is desirably fabricated from a metal with high thermal conduction such as, for example, copper or cast or cast bronze. Then, the tip face member 12 is cleaned and prepared for copper welding which includes cutting and inserting copper welding rings not illustrated at the lower ends of the nozzles. The cooling fluid baffle member 22 is then placed in the mating recesses, described below, provided on the radiatingly extending radially extending blades 32, which extend radially upwardly from the inner surface 30 of the member 12 face of the tip. The nozzles 16 are then inserted into the corresponding openings in the coolant baffle member 22 in alignment with the outlets 14 of the tip face member. By last. The active material well member 20 is placed on top of the upper ends of the nozzles in such a way that their inlets 18 are in alignment with the upper ends of the nozzles 16. The assembly is then secured, the lower ends of the nozzles weld with copper to the upper ends of the exits of the member of each of the tip, the deflector member of the cooling fluid is welded to the nozzles, the upper ends of the nozzles are welded to the inlets of the well member of active materials, and the upper end of the support post is welded to the well member of active materials. Although shown and described as separate components assembled into a collective whole, it is also contemplated that the nozzles 16, the active material well member 20 and the baffle member 22 may be a single component. For example, these may be formed as a unitary copper or bronze casting in a manner similar to that described in US Patent No. 6,217,824, the disclosure of which is incorporated herein by reference thereto. It will be appreciated that by forming the nozzles 16, the well member 20 of active materials and the baffle member as a single component, several of the above-mentioned mounting steps can be eliminated. FIG. 3 illustrates how the mounting 10 of the tip is secured to a lower end of the drum portion of the spear passes faerieaeien falls metals e fiada by water. Typically, a lance for water-cooled metal fabrication includes a plurality of concentrically arranged metal tubes, for example made of steel. As shown in FIG. 3, the lance drum has a central tube 34 welded or otherwise appropriately secured to the well member 20 of active materials. The central tube 34 defines a central passage 36 for supplying pressurized active materials to the nozzles 16. An annular space formed between the tube 34 and a second tube 37 defines an inlet passage 38 of the cooling fluid, which is connected to a non-delivering supply. illustrated cooling water and supplies water to the tip assembly of the lance. Preferably though not necessarily, the cooling fluid baffle member 22 includes at least one internally formed bypass passage 40, which desirably corresponds in number and position to the nozzles 16 to allow cooling of the outermost radially areas thereof. During operation of the lance, the cooling water flows continuously through the passages 38 for supplying the cooling fluid to the passage means defined by the lower surface of the well member 20 of active materials, the deflector member 22 of the cooling fluid and the internal surface 30 of the tip face member 12 and then to the return passage 42 of the cooling fluid. More particularly, the cooling water flows down through the passage 38 into a first flow space of the cooling fluid defined by the lower surface of the well member 20 of the active material and the deflector member 22 of the cooling fluid and the or bypass passages 40 (if present), around the outer surfaces of the nozzles 16, and through a central opening 44 in the cooling fluid deflector member 22. When the cooling water passes through the central opening 44, its direction of travel is changed. Specifically, the overall conical profile of the protrusion 28 redirects the flow of the cooling water from substantially parallel to substantially perpendicular to the longitudinal axis 26 of the lance as it flows through a second flow space of the cooling fluid defined by the member 22 of deflector of the cooling fluid and the internal surface 20 of the member 12 of the tip layer. While in the second flow space of the cooling fluid, the cooling water flows radially outwardly and around the outer surfaces of the outlets 14 of the tip face member and between a plurality of radially arranged vanes 32, described below. Upon leaving the second flow space of the cooling fluid, the cooling water is combined with the cooling water leaving the or bypass passages 40, if present, and enters a return passage 42 of the cooling fluid formed between the second and the third tube 37, the outermost tube 46 whereby water is returned from the tip of the lance to the cooling water supply and is recirculated again through the lance. The volumes of the cooling water flow can be expected to vary from about 100 to about 2000 gallons per minute (GPM) through a typical water-cooled lance, although larger and smaller flows can be adjusted by the present invention as may be desired or necessary. As seen in several of the figures, the protrusion 28 is preferably located coaxially with the central longitudinal axis 26 of the tip assembly of the lance. The outline of the protrusion 28 is substantially preferably conical, although this may have a somewhat convex or concave profile relative to the central longitudinal axis 26. According to a currently preferred embodiment, the profile of the protrusion 28 is substantially conical, whereby the circumferential wall of the protrusion diverges from the central longitudinal axis 26 at an angle (FIG 5) of between about 20 ° -50 °, more preferably about 35 °. Additionally, the exterior of the face of the tip face member 12 is preferably formed, either during or after its manufacture, with a recess 48 (FIGS 1, 2 and 5) which generally corresponds to the protrusion 28. The recess 48 is desirable because it substantially balances the thickness of the working perimeter of the tip face member 12 in the region of the protrusion, which promotes the substantially uniform thermal characteristics therethrough. In addition, as discussed below in connection with FIG. 7, the contour of the recess 48 can be optimized to achieve a preferred "dent profile relationship". FIGS. 4 and 5 disclose a currently preferred configuration of blades 32 directing the flow of refrigerant. Unlike those described in U.S. Patent Nos. 3,322,419 and 3,337,203 and U.K. Patent No. 1,255,082, the vanes 32 extend essentially over the axial distance or the complete height between the inner surface 30 of the face member 12 spear point and the lower surface of the coolant flow deflector member 22, and essentially the entire radial distance from the central protrusion 28 to the annular return passage 42 of the cooling fluid. A first group of blades, identified by the reference number 32a, intercept and are in contact with the outlets 14 and the nozzles, whereby the vanes 32a provide structural support to the outlets and the nozzles which serves to minimize the distortion of the face member 12. the tip during the operation of the spear. In non-reinforced spearhead mounts, the working face is distorted under normal operating conditions. This typically results in internal distortion of the nozzles approximately two inches from the outlet of the nozzle. This distortion of the nozzle causes the oxygen jet to act non-symmetrically, which in turn reduces the efficiency of the jet, increases the slag of FeO and reduces the metallic performance. By building them as an integral part of the nozzles 16, the blades 32a function as reinforcing ribs that minimize distortion of the nozzle. A second set of blades, identified by the reference number 32b, are preferably circumferentially spaced halfway between the adjacent blades 32a. As best seen in Fig. 5, each of the vanes 32b is preferably formed, such as by machining, or the like, with a depression 50 having a contour which is adapted to receive the lower surface of the member 22 of Coolant flow deflector. A preferred, but not limiting, form of the depression is a lobe-shaped concavity in general. It is preferred that the bottom surface of the coolant baffle member is also formed or machined to produce a shape that essentially matches the depression 50. In this manner, the cross-flow of the coolant between the vanes is effectively prevented thereby optimizes the control of the refrigerant flow during the operation of the lance. The provision of the blades 32a and 32b radiating from the protrusion 28 stabilizes the flow paths of the highly controlled cooling water, which improves the ability of the spearhead assembly to transport water at a high speed and cool more evenly the tip of the spear. Additionally, the vanes provide structural reinforcement for the face of the spear tip and nozzles, resulting in improved spearhead performance and service life. FIG. 6 shows a currently preferred lift transverse configuration of the blades 32. According to the present invention, each blade has a height "H" and an average thickness "T" (measured at about H / 2) at any point along the length of the blade. the radial extension of the blade. H is the axial distance between the inner surface 30 of the face member 12 of the spear tip and the lower surface of the deflector member 22 of the coolant flow. As seen in Fig. 5, since the inner surface 30 of the tip face member 12 is preferably defined by a preferably frustroconically, convex shape, the height "H" of the vanes varies from the protrusion 28 through the nose. radial extension of the blades. It is also preferable that the working face has a shape corresponding to that of the inner face 30 to allow a tip of substantially uniform thickness at its distal end, thereby minimizing the potential of "hot spots" and uneven cooling of the face of work. That is, according to the present invention, the vanes 32 have thicknesses that vary as a function of the radial distance from the protrusion 28 to the perimeter of the face member of the spear tip. This thickness is represented by the variable "T" in FIG. 6 and can be seen more clearly in FIG. 4. It will be understood, however, that the working face of the face member 12 of the spear tip can be essentially flat. In which case the height "H" and the thickness "T" of the blades 32 would be essentially constant through the radial extension of the blades beyond the central protuberance 28. As part of the present invention, a "coolant booster ratio" or "CRR" with respect to the vanes is defined as T / H. Without wishing to be in agreement with the theory, it is believed that a CRR of about 0.3 contributes with the superior cooling characteristics of the spearhead assembly according to the present invention versus conventional lancet assemblies known in the art. Returning to FIG. 7, there is shown a limited cross section of the central region of the face member 12 of the lance tip. That figure illustrates the flow path of the cooling water as it passes through the coolant flow deflector member 22 and is gradually diverted outwardly by the inner boss 28. They are also shown in FIG. 7 certain dimensional variables that define the overall size and shape of the gap 48 formed in the working face of the tip. As shown in FIG. 7, the dimension "D" is the diameter of a circle defined by the outermost projection of the working face of the spearhead that circumscribes the gap 48. As is also represented in that figure, "d" is the depth of the gap 48 from the outermost projection of the outer surface or working surface of the spear point to the deepest point of the gap when measured along the longitudinal center axis 26 of assembly 10. The "dent profile relationship" or "DPR" is defined as D / d and it has been observed that a beneficial DPR is approximately equal to 2.7. A known failure mechanism in a typical BOF lance is the wear of the central face caused by the slag and / or the metal entrained in the furnace gases. In the present invention, a recess 48 of appropriate depth "d" relative to dimension "D" can substantially reduce the exposed area of the working face of the tip which reduces wear on the face. In contrast, a relatively flat tip face would have a high DPR ratio. In any design, however, the final profile of the gap depends on an arrangement between the requirements of the internal distribution profile of the water, the separation of the nozzle leg and the thickness of the face. Like a charitable CRR (and, again, without pretending to agree with the theory) it is believed that a beneficial DPR contributes to the superior cooling characteristics of the spearhead assembly according to the present invention, versus the assemblies of conventionally constructed spearheads known in the prior art (as observed by the inventors through empirical comparative experimentation). The following are among many, the advantages of a spearhead assembly constructed in accordance with the present invention.; 1. Oxygen jets with superior moment that result in an increased height or distance of the lance from the metallic bath (which, in turn, translates to reduced potential for damage to the lance during the operation;
2. Reduced erosion of nozzle outlet; 3. Less decay of the oxygen jets that result in improved mixing of the bath and less slag of the FeO; 4. less decay of the oxygen jets that results in a lower consumption of oxygen per ton of steel produced; 5. Extended service life of the spear without increasing the FeO slag; 6. Increased flow of cooling water (by reducing spiral currents and other flow disturbances, 7. less temperature differentials at the tip of the lance, 8. increased efficiency of cooling water (through convection) in virtue of radial blades; 9. improved distribution of cooling water and velocity by virtue of the central protuberance that redirects the flow; 10. increased volume of cooling water via a less restrictive design resulting in less friction (more specifically , a water cooling system of the metal fabrication laminator is evaluated at a given flow rate for a given pressure drop across the lance ("pump curve" a / k / a), by reducing the pressure drop from the tip, the pump flow increases without any additional energy requirement 11. face or surface of the tip reinforced by virtue of the radial blades and the support post, resulting in a reduced distortion of the tip face; 12. nozzles reinforced by virtue of the radial blades, resulting in reduced tip distortion; 13. reduced exposed area in the center of the tip face by virtue of the central recesses corresponding generally to the central protuberance; and 14. reduced exposed area for the adhesion of the steel / slag to the center of the tip face (which can result in localized calcination) by virtue of the central recess that generally corresponds in shape to the central protrusion. Although the invention has been described in detail for purposes of illustration, it should be understood that such detail is only for that purpose and that variations may be made therein by those skilled in the art without departing from the spirit and scope of the invention as it is claimed here. For example, although the illustrated lance assembly is constructed with a single supply conduit for the centrally located active material, it is possible that the lance may contain more than one such passage to supply similar or different active materials. Likewise, it is also possible that the inlet passage of the cooling water can be disposed internally rather than externally of one or more of the passages of active materials.