Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D41/00—Casting melt-holding vessels, e.g. ladles, tundishes, cups or the like
  • B22D41/50—Pouring-nozzles
  • B22D41/502—Connection arrangements; Sealing means therefor

Definitions

• the present invention relates to a thermally insulating pouring tube intended to be placed between the pouring orifice of a first metallurgical container such as a ladle and a second metallurgical container such as a tundish.
• the tube material is highly refractory such as silica, magnesia, zirconia, and isostatic pressed carbon.
• these tubes require long and costly preheating before casting the liquid metal, to limit the risks of solidification of this metal in contact with their wall, this solidification can cause a complete sealing of these tubes.
• these tubes are heavy, therefore difficult to handle and are very expensive.
• the organic constituents of the material of these tubes decompose but the cohesion of the tube is maintained as a result of the sintering of the inorganic particles, under the effect of the heat given off when the liquid metal passes through it. inside the tube.
• the decomposition of organic constituents and the sintering of inorganic particles give the material a porous structure with a high power of thermal insulation.
• the material tends to crumble quickly, so that at the end of casting, the seal is no longer formed between the pouring tube and the pouring nozzle on which its end is engaged.
• the object of this invention is therefore to remedy this drawback, by creating a pouring tube having all the advantages of the tubes described in the patent. French n ° 2333 599 while having a considerably extended lifespan.
• the pouring tube covered by the invention is intended to be placed between the orifice of a first metallurgical container and a second metallurgical container, one end of this pouring tube being intended to be engaged in a removable and substantially watertight on the pouring nozzle or an adapter extending the nozzle of the first container, this pouring tube being made of a material constituted by inorganic particles, erentually added with fibers, coated in a binder, these inorganic particles being sinterable under the effect of heat of the liquid metal passing through this tube.
• this pouring tube is characterized in that its end intended to be engaged on the pouring nozzle comprises a ring of refractory material, the internal surface of this ring being intended to come into direct contact with the nozzle of couiee or with the adapter extending the nozzle.
• This refractory ring thus mechanically reinforces the part of the pouring tube which does not undergo the sintering effect indicated in the introduction to this description.
• this refractory ring does not reduce the insulating properties of the pouring tube and does not entail any risk of solidification of the liquid metal, since this ring does not come into direct contact with this metal.
• the height of the above-mentioned refractory ring is at least equal to the distance over which the end d tube is intended to be engaged on the pouring nozzle of the first metallurgical container.
• the pouring tube is produced by molding and the ring of refractory material is fixed to the material of the wall. of the tube, during this molding.
• the fixing of the refractory ring to the tube can thus be carried out without any additional difficulty.
• this end of the pouring tube also includes a refractory ring.
• this end of the pouring tube is not liable to wear out by melting on contact with the liquid metal, and therefore, the life of this tube is further extended.
• FIG. 1 is a view in partial longitudinal section, of the bottom of a ladle and a tundish placed under the latter, a conformal pour tube the invention being disposed under the outlet nozzle of the ladle
• FIG. 2 is a partial longitudinal sectional view, on a large scale, showing the upper end of the pouring tube, engaged on the pouring nozzle, as well as the jet of liquid metal passing in this tube,
• FIGS. 3 to 7 are views in partial long tudinal section, showing various variants of the invention.
• FIG. 8 is a view in longitudinal section of the lower end of an advantageous version of the pouring tube according to the invention, immersed in the liquid metal contained in the pouring distributor,
• Figure 9 is a longitudinal sectional view of a pouring tube engaged on an adapter for another nozzle with drawer and Figure 10 is a / Variant in longitudinal section.
• the bottom of the ladle 1 includes a pouring nozzle 3 made of a highly refractory material such as silica, refractory brick magnesia or zirconia.
• This pouring nozzle 3 is disposed above a pouring distributor 4.
• the upper end 5a of a pouring tube 5 slightly truncated, the lower end of which is intended to be immersed in the liquid metal which is introduced into the tundish 4.
• the means for removable attachment of the coulter tube 5 to the nozzle 3 are not shown. These means can be of the kind described in French patents No. 2,333,599 and No. 77 35,874 of 11/29/1977.
• the pouring tube 5 comprises an outer protective sleeve 6 made of metal sheet, for example of steel, which surrounds an inner wall 7 made of a thermally insulating and light material. This material consists of inorganic particles (silica, alumina, magnesia), added with inorganic fibers, coated in an organic binder such as a synthetic resin or an inorganic binder.
• the end 5a of the tube 5 engaged on the pouring nozzle 3 comprises a ring 8 of refractory material, the internal surface 8a of this ring being in direct contact with the casting nozzle e 3.
• the refractory material of the ring 8 is of the same nature as that of the nozzle 3. It can be, for example, silica, magnesia, refractory brick, isostatically pressed carbon or chamotte. These materials all have the advantage of having excellent mechanical and thermal resistance. In addition, they have a very high dimensional stability, so that it is possible to obtain a very precise adjustment of the ring 8 on the nozzle 3.
• the height of the refractory ring / is greater than the distance over which the end 5a of the tube 5 is engaged on the pouring nozzle 3.
• the thickness of the wall of the refractory ring 8 is substantially equal to the thickness of the wall 7 of the tube 5, so that the inner Sa and outer surfaces of the ring 8 are located substantially in the extension inner 7a and outer surfaces of the wall 7 of the tube 5.
• the thermally insulating wall 7 is obtained by molding in a mold, the outer wall of which is formed by the sheet 6. This molding makes it possible to obtain direct adhesion of the material of the wall 7 to the sheet 6. In addition, the direct connection between the material of the wall 7 and the refractory ring 3 can also be obeyed during this molding. However, other means of fi xati on the ring 8 can be provided for than the sheet 6 and / or to the insulating wall 7, such as screws, cement or glue. In the variant embodiment of the figure, the contact surface between the refractory ring 9 and the insulating material constituting the wall 7 of the pouring tube comprises an annular recess 10.
• this annular step 10 makes it possible to maintain a certain thermal insulation in the part 7b of the wall 7.
• the thickness / of the ring 11 is less than that of the wall 7 of the. tube, the inner surface 11a of this ring 11 being disposed substantially in the extension of the internal surface 7a of the wall 7.
• This ring 11 is thus entirely embedded in an annular recess 7c formed at the end of the tube. This arrangement is favorable as regards the solidity of the fixing of the ring 11 to the wall 7 and the thermal insulation in line with the ring 11 in the part 7d.
• the refractory ring 12 has an internal diameter smaller than the internal diameter of the tube and the external surface 12a of this ring is arranged in the extension of the internal surface 7a of the tube. The fixing of this ring 12 in the tube is ensured by the interlocking which results from the taper of the outer surface
• This fixing can possibly be reinforced by gluing or other suitable mechanical means.
• the ring re fraction 13 has an outside diameter greater than the inside diameter of the tube and this ring is partly embedded in an annular shoulder 13a formed in the wall 7.
• the refractory ring 14 presents at the upper part of its inner surface an annular widening 14a, receiving the free end of the nozzle 3.
• the shoulder 14b constitutes a stop which ensures perfect axial positioning of the tube with respect to the nozzle, avoiding any risk of relative jamming between the nozzle and the ring 14.
• the rings according to the invention undergo no chemical transformation.
• these rings are made of a refractory material of the same nature as that of the nozzle 3, these rings undergo thermal expansion comparable to that of the nozzle 3. so that no play is formed between these rings and the nozzle.
• the junction thus remains perfectly sealed and any possible introduction of air inside the tube is avoided. and any risk of oxidation of the liquid metal.
• the zone 16b of the wall 7 of the tube 5 would be completely decomposed and this would necessarily result in a significant annular clearance between the upper part of the wall 7 of the tube and the nozzle 3. This play would thus allow the introduction of air inside the tube and consequently, the oxidation of the liquid metal, so that this tube would no longer be usable for a new casting.
• the decomposition of the zone 16b of the wall 7 of the tube 5 does not cause any drawback, since the ring 8 ensures at the end of casting, as at the beginning of it, a perfect seal between the nozzle 3 and the tube 5.
• the part of the wall 7 located below the zone 16b remains perfectly coherent and retains a high power of thermal insulation due to the porous structure obtained by sintering .
• the tube according to the invention remains useful. readable for several successive flows.
• the outer sheet 6 melts in contact with the liquid metal and the same applies to the material of the wall 7 of the tube. This can also prevent the reuse of the pouring tube 5.
• This ring 16 corresponds at least to the depth of immersion of the end of the pouring tube in the metal 17 contained in the tundish distributor.
• the thickness of the wall of this ring 16 is substantially equal to the thickness of the wall 7 of the tube, plus that of the sheet 6. This sheet 6 completely covers the wall 7 of the tube and stops at the level of the ring 16 to avoid direct contact with the liquid metal 17.
• the ring 16 can be fixed to the wall 7 of the tube 5 during the molding of this wall, as in the case of the upper rings shown in FIGS. 1 to 7.
• the fixing of this ring 16 to the wall 7 is improved when the contact surface of this attachment has an annular recess 16a as shown in FIG. 8.
• the end of the tube 5 does not risk being damaged in contact with the liquid metal 17, and therefore, this tube can be reused for several successive castings.
• an adapter 18 is interposed between a short nozzle 19, and the pouring tube 5, as indicated in FIG. 9.
• This nozzle 19 is part of the drawer 20 of a system of 'opening and closing called "drawer nozzle" of the orifice of a ladle.
• the adapter 18 made of refractory material has at its upper part an annular cavity 21 which receives the end of the nozzle 19.
• the frustoconical lower end 18a of the adapter 18 is nested in the interior surface 11a of a refractory ring 11.
• the refractory ring 11 plays the same role with respect to the adapter 13 as with respect to the pouring nozzle 3 in the case of the preceding embodiments.
• This adapter 18 is necessary in all cases where the pouring nozzle is too short. This adapter 18 sometimes also acts as a box for collecting the gases intended to be blown into the liquid steel.
• the shape and method of attachment of the upper refractory ring can be modified to suit all possible shapes of nozzles, provided that the inner surface of the ring is in direct contact with the outer surface of the nozzle.
• the shape and the method of fixing the lower year 16 can be modified, provided that the liquid metal contained in the tundish does not come into direct contact with the insulating wall 7 and with the external sheet 6.
• the pouring tube according to the invention can be used for other metallurgical vessels than the ladles and the tundish.
• the outer sheet it is advantageous that the outer sheet
• annular bead 22 projecting outwards (see FIG. 2) defining an empty annular space 23 between the sheet and the thermally insulating inner wall 7.
• This bead 22 serves to hold, by means of a support 24, the tube 5 in abutment against the external surface of the nozzle 3.
• the empty annular space 23 communicates with a horizontal tube 25 connected to a source of non-oxidizing or inert gas such as argon.
• This bead 22. is preferably arranged opposite the non-sinterable zone 16b adjacent to the annea 8 of the wall 7, which remains porous.
• the gas introduced into the annular space 19 diffuses through the wall 7, in a regular manner, all around the latter and penetrates the interior of the tube 7, providing the liquid metal with additional protection against the oxidation.
• the external sheet 6 has at its upper part a second annular bead, constituted by a winding 26 from the edge of the sheet towards the inside.
• This winding 26 is supported on the adjacent end of the insulating wall 7.
• This winding 26 defines an annular duct communicating with an intake manifold 28 of inert gas such as argon. Winding 26 presents a series of openings 27 directed radially towards the axis of the tube 5.
• the advantage of this arrangement is as follows: since the ring 8 is made of hard refractory material, this material is liable to flake when it is brought too suddenly into contact with the refractory and hard material of the same kind as the nozzle 3 or the extension 19.
• the scales thus formed can generate air inlets inside the pouring tube 5, by suction (Venturi effect).
• the winding 26 provided with openings 27 makes it possible to produce jets of argon or other inert gas all around the nozzle 3, thus avoiding any penetration of air inside the tube 5.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Casting Support Devices, Ladles, And Melt Control Thereby (AREA)
• Thermal Insulation (AREA)
• Treatment Of Steel In Its Molten State (AREA)
• Casting Or Compression Moulding Of Plastics Or The Like (AREA)
• Insulating Bodies (AREA)
• Rigid Pipes And Flexible Pipes (AREA)
• Rear-View Mirror Devices That Are Mounted On The Exterior Of The Vehicle (AREA)
• Continuous Casting (AREA)
• Furnace Charging Or Discharging (AREA)
• Furnace Housings, Linings, Walls, And Ceilings (AREA)

Priority Applications (1)

Applications Claiming Priority (1)

Publications (2)

Family

ID=9237242

Family Applications (1)

Country Status (10)

Families Citing this family (11)

Family Cites Families (7)

• 1980
  • 1980-11-26 MX MX190272A patent/MX157119A/es unknown
  • 1980-11-26 DE DE8080902236T patent/DE3070789D1/de not_active Expired
  • 1980-11-26 WO PCT/FR1980/000169 patent/WO1982001836A1/fr not_active Ceased
  • 1980-11-26 AT AT80902236T patent/ATE13829T1/de not_active IP Right Cessation
  • 1980-11-26 DE DE198080902236T patent/DE65514T1/de active Pending
  • 1980-11-26 EP EP80902236A patent/EP0065514B1/de not_active Expired
• 1981
  • 1981-11-03 ZA ZA817593A patent/ZA817593B/xx unknown
  • 1981-11-03 CA CA000389301A patent/CA1183325A/en not_active Expired
  • 1981-11-06 AU AU77172/81A patent/AU544222B2/en not_active Ceased
  • 1981-11-25 ES ES507420A patent/ES8301131A1/es not_active Expired
• 1985
  • 1985-05-22 US US06/737,052 patent/US4660808A/en not_active Expired - Lifetime

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events