US2406147A - Apparatus for producing metal - Google Patents

Description

R. K. HOPKINS V APPARATUS FOR PRODUCING METAL Aug. 20, 1946.

Filed May 9, 1944 Q 3 H n i 7 a A w A, w m a 0 o 1 O 2. 8 0 .l 3 32 J 7 3 1:5: 3 Q Ln I1 7 9. w 5 9 w 2 m 3 M.

Patented Aug. 20, 1946 APPARATUS FOR PRODUCING METAL Robert K. Hopkins, New York, N. Y., assignor to The M. W. Kellogg Company, New York, N. Y., a corporation of Delaware Application May 9, 1944, Serial No. 534,828

4 Claims.

The present invention relates to improvements in the construction of vessels for holding molten metal, and more particularly to improvements in the construction of metallurgical vessels of the type having discharge orifices. In its broader aspects, the term metallurgical vessels is intended to apply to any vessel adapted to hold molten metal. In accordance with certain aspects of the invention, such a vessel may, for example, consist of a furnace crucible in which metal is produced, refined or otherwise metallurgically treated, or may consist merely of a receptacle for transferring molten metal from a furnace to a mold.

In the usual metallurgical vessel, such as the conventional crucible furnace having a discharge orifice through which the molten metal is streamed, if the orifice should become fouled, eroded or otherwise impaired for use, pouring must be stopped, and the metallurgical processes being carried out interrupted until the orifice structure has been repaired or replaced.

One object of the present invention is to provide a new and improved metallurgical vessel constructed to permit continuous ouring of metal therefrom and continuous Operation of any metallurgical process which may be progressing in said vessel, even though its pouring orifice structure should be impaired beyond utility.

In carrying out certain features of the present invention, the metallurgical vessel in the form of a cup-shaped crucible is mounted on an inclined axis and is provided with at least two duplicate orifice structures or devices interspaced around said vessel, and arranged in a plane substantially at right angles to said axis. The vessel is rotatable about this axis, and when said vessel is in pouring position with respect to one of the orifice structures, the other orifice structure is disp above the horizontal level of the fluid in said vessel and out of pouring position. When the lower active orifice structure requires to be replaced or repaired, the vessel is rotated about its inclined axis, to move said orifice structure out of pouring position and the upper inactive orifice structure into pouring position. This transition from one orifice structure to the other can be quickly effected with minimum of pouring interruption. While the damaged orifice structure is in elevated inactive position, it can be repaired Or replaced without interfering with the pouring through the other orifice structure. By rotating the vessel into a position intermediate of the extreme pouring positions of the two orifice structures, it is possible to raise both of said structures above the level of the liquid in the vessel, and thereby completely shut off flow of liquid from said vessel. In this manner, an easy and eiTective expedient is provided for controlling flow of the molten metal from the vessel without the use of valves or stoppers.

As another feature of the present invention, means for producing and/or heating the metal in the vessel are arranged and constructed to continue their operation without interruption irrespective of the rotative position of said vessel.

Various other objects, features and advantages of the invention will be apparent from the following particular description, and from an inspection of the accompanying drawing, which shows somewhat diagrammatically partly in vertical section and partly in side elevation an apparatus embodying the features of the present inventiton.

Referring to the drawing, the apparatus of the present invention comprises a metallurgical vessel 18 adapted to contain molten metal Ii, such as ferrous metal, and shown specifically as a cupshaped crucible furnace of circular cross-section. This vessel id is shown comprising an outer metal sheil l2 with an inner refractory lining !3, but as far as certain aspects of the invention are concerned, said vessel may be made entirely of metal such as copper, and may be provided with a jacket to permit liquidcooling of the vessel.

As a feature of the present invention, the vessel in is tilted along an inclined axis A, and is mounted for rotary discharge emplacement. For that purpose, the vessel i ii is fixed at its bottom end to an inclined shaft M which extends along the axis A, and which is suitably journalled. Any suitable means may be provided for rotating the shaft M. In the specific form shown, a worm wheel l5 fixed to the shaft I4 meshes with a worm i6 driven by a hand crank or by a motor (not shown).

The vessel 59 is provided with a plurality of equally duplicate discharge orifice structures or devices ii, two being shown disposed on diametrically opposite sides of said vessel, and extending in a plane substantially at right angles to the axis A. Each of these orifice structures ll comprises a tapering opening it in the wall of the vessel iii, and a nozzle or spout 2d of suitable heat-resistant material, seated against the refractory lining l3 h its apertlu'e in registry with the wall opening iii. spout 29 is desirablv removably mounted to permit its easy replacement. For that purpose, the spout 29 has a base section it affording a shoulder 22 which is clampingly engaged at its diametrically opposite sides by a pair of metal holding dogs 23, secured to the shell ['2 of the vessel Ill by 3 studs 24. By loosening studs 26, the dogs 23 may be swung out of holding engagement with the spout 20, and said spout removed for replacement, for repair or for cleaning.

The molten metal H in the vessel H3 is desirably maintained under a floating blanket of flux or slag 26 having the usual metallurgical function, such as that of refining the metal and/or conserving its heat. This flux 26 may be of any well-known composition suitable for performing this function.

During normal pouring operations, the metal H in the vessel [9 is maintained at a level above the lowermost position of either one of the discharge openings id, as shown in the drawing. In this position of the discharge openings E8, the molten metal l i will flow through the lowermost opening and through its spout Zil as shown, while the other opening it is in elevated position above the level of the slag it. While the upper orifice structure ii is inactive, it may be replaced, repaired or cleaned so that it can be made ready for immediate use. In the meantime, the metal H may be teeming through the lower active spout 2e into a suitable mold 2'4, such as an ingot mold.

In extreme pouring position of the vessel ii], the elevated inactive discharge opening E3 as well as a substantial portion of the refractory lining it around said opening is disposed above the slag 26. This permits the refractory lining It to be patched up around the elevated discharge opening lii, in case such repair work is required.

When it is necessary to clean, replace or repair the lower active orifice structure ill, the vessel in! is rotated about its inclined axis A, so that this orifice structure is raised above the level of the slag 25 out of pouring position, while the other conditioned orifice structure ll is lowered into pouring position. This rotary transition of the vessel ill between. the two extreme positions of the orifice structures H can be eifected with minimum of pouring interruptions.

When it is desired to shut oif the flow of metal, the vessel NJ is rotated in intermediate position between its two extreme pouring positions. In this intermediate position, the two orifice structures I! will be disposed in horizontal alignment above the level of the slag 26 in approximate position B shown in dot and dash lines. In this manner, an easy and expeditious expedient is ailorded for cutting off or turning on the metal flow without the use of valves or stoppers.

The vessel It) desirably constitutes a furnace in which the metal is continuously produced as it is being discharged into a mold. As an additional feature of the present invention, the metal producing means is constructed and arranged to operate continuously without interruption, even while the vessel H1 is being rotated between its two extreme operating positions. This metal producing means desirably comprises one or more consumable electrodes 39, one being shown, containing at least some of the ingredients of the metal to be produced, and having its lower end submerged in the slag 26. Electrode 3i! may be of the kind and character shown and described in my prior Patent No. 2,191,479, issued February 27, 1940. Current of sufiicient intensity is discharged across this gap 3l to create a metal fusing zone in and around said gap. To create this metal fusing current discharge across the gap 3|, the electrode 36 and the metal H are electrically connected in the same circuit. The

4 electrical connection to the electrode 30 may be established, as for example through a contact nozzle 32 connected to a suitable source 33 of electric current through a power feed and control unit 34, and embracing said electrode with a snug slide fit loose enough to permit the feeding of said electrode through said nozzle, but tight enough to maintain contact between said nozzle and said electrode. The electrical connection of the deposited metal H into the circuit of the contact nozzle 32 may be eifected, as for example, through a lead 36 connected into the power feed and control unit 34.

The electrode 30 may be lowered into the vessel H3, or may be raised from said vessel by any suitable means. In the specific form shown, the electrode 30 is supported through a clamp 38 on a hoist 31 which may be elevationally moved through a pair of feed screws 39 adapted to be rotated in unison through a hand or motor unit (not shown).

The electrode 3!! extends substantially verti cally as shown, and is desirably arranged so that its lower end is approximately near or at the axis A. With this arrangement, the vessel Ill can be rotated without interfering with the metal producing operation of the electrode 30, and without substantially altering the position of the lower end of said electrode relative to the sides of the vessel.

As the molten metal is continuously being discharged from the vessel Ii] at a certain rate through one of the orifice structures ll, metal is continuously being produced in said vessel at substantially the same rate. As the electrode is consumed, it is fed lengthwise into the metal fusing zone at a rate controlled to maintain the level of the molten metal l i in the vessel Ill substantially constant. This controlled movement of the electrode 39 may be eifected in any suitable manner, as for example through a pair of feed rolls 40 mounted on the hoist 37 and disposed on opposite sides of the electrode 39 in frictional engagement therewith. At least one of these feed wheels MI is driven from a motor 4!, while the other wheel may be positively driven from said motor or may be merely an idler serving as a guide for the electrode 30. The electrode 30 may be formed continuously and progressively from skelp as it is being fusibly fed into the Vessel l 9.

To control the feeding movement of the electrode 38, there is desirably provided a non-consumable pilot electrode 45, disposed alongside of said electrode, and having its lower end submerged in the slag 2%. This pilot electrode 45, disposed alongside of said electrode, and having its lower end submerged in the slag 26. This pilot electrode 35, which is supported on the hoist 31, as for example by the clamp 38, may be made of high heat conductive metal such as copper, and may be formed with chambers through which a cooling liquid is circulated by means of inlet and outlet connections A5 and 47. Pilot electrode 45 is connected by a lead 48 to the control unit 34, and controls the feed movement of the electrode 30, as for example, by the voltage drop across the gap separating said pilot electrode from the metal H in the vessel ill. The electrode feed motor ll is connected to the control unit 34 by the leads 49, and when the pilot electrode gap changes in length from a predetermined value, this control unit M in response to this change operates said feed motor correspondingly, and thereby causes the electrode til to be fed at a rate necessary to maintain the level of the metal i l substantially constant. The details of the control unit 34 and the manner in which it controls th feed of the electrode 30 are not per se part of the present invention, and since they are wellknown in the art, they are not herein described with any particularity.

In order to maintain the metal H near and around the actual discharge opening 3 sumciently fluid to flow freely, there is desirably provided a non-consumable upright electrode 50 submerged at its lower end in the slag 26, and disposed directly about this opening. This heating electrode as may be of hollow copper construction chambered for the circulation of a cooling medium therethrough, as in the case of the pilot electrode 45, and is supported on the hoist 31, as for example a clamp 5!. A lead 52 connects the heating electrode 58 to the power feed and control unit 3%. By maintaining a current discharge across the gap separating the electrode 59 from the metal H, freezing of the metal in the active discharge opening I8 is prevented, and free flow therethrough continuously maintained. The current discharge from or to this electrode 50 can be controlled automatically by the temperature of the metal near or at the active discharge opening :3.

It should be noted that th three electrodes 30, 45, and 50 are so supported and positioned as to maintain their relative position with respect to the sides of the vessel 10, irrespective of the I rotat'fve position of said vessel, and that the heating electrode 50 will remain directly above either one of the discharge openings l3 in either extreine relative position of said vessel.

As many changes can be made in the above apparatus, and many apparently widely different embodiments of this invention can be made without departing from the scope of the claims, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

What is claimed is:

1. In combination, a metallurgical vessel having two duplicate discharge openings, a heating electrode in said vessel, and means for rotating said vessel to bring either one of said openings into pouring position below said electrode while moving the other opening out of pouring position.

2. A metallurgical vessel supported for rotation about an inclined axis, and having two discharge openings diametrically opposed with respect to said axis whereby one of said openings Will be in pouring position below the level of the molten metal in said vessel, while the other discharge opening will be above the top level of the fluid in said vessel.

3. In combination, a metallurgical vessel supported for rotation about an inclined axis, and having two discharge openings substantially in a plane transverse to said axis, said openings being arranged whereby one of said openings will be in pouring position below the level of the molten metal in said vessel, while the other discharge opening will be above the top level of the molten content of said vessel, and a heating electrode in said vessel above one of said opening in its pouring position.

l. In combination, a crucible furnace supported for rotation about an inclined axis, and having two discharge openings diametrically opposed with respect to said axis, whereby one of said openings will be in pouring position below the level of the molten metal in said furnace, while the other discharge opening will be above the top level of the molten content of said furnace, orifice devices removably connected to said furnace adjacent to and in registry with said openings respectively, whereby said devices may be removed for repair or replacement while their corresponding discharging openings are out of pouring position, electrode means for continuously producing metal in said furnace while metal is being discharged therefrom through one of said openings, and a heating electrode in said furnace above one of said openings in its pouring position.

ROBERT K. HOPKINS.

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