US2367123A - Apparatus for producing metal bodies - Google Patents

Description

Jan. 9, 1945. R. K. HOPKINS APPARATUS FOR PRODUCING METAL. BODIES Filed May 8, 1943 INVENTOR Roberiljya akam ATTORNEY ing stool.

Patented Jan. 9, 1945 APPARATUS FOR PRODUCING METAL BODIES r Robert K. Hopkins, New York, N. Y., assig'nor to. The M. W. Kellogg Company, New York, N. Y;, a corporation of Delaware Application May 8,1943, Serial No. 486,479

' 2 Claims. (01. 22-512) The present invention relates-to the'art of producing and casting metal ingots.

- Ingotscan be cast by producing and. depositing molten metal in a fumace'and withdrawing the solidified metal from said furnace either continuously or by a step by step movement. It is a difficult problem to provide a'satisfactory anchorage for the initially deposited metal so that the solidified metal can be withdrawn from the furnace. If a starting plug is employed as a support and anchorage for the initially deposited metal, the plug must be made of finished metal of the desired analysis thereby increasing the cost. Also, since the plug section must subsequently be cropped from the final in'got the I metal yield is reduced.

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 a diagrammatic vertical section of a form of apparatus which embodies thepresent invention, and which may be employed to carry out the process of the invention.

Referring to the drawing, there is shown an apparatus which may be employed in accordance with the present invention'to continuously form an ingot of finite predetermined length. This apparatus includes an ingot mold furnace l0 One object of the .present invention is to provide a new and improved continuous casting. ap-

paratus affording an effective pulling grip on the solidified metal in the furnace without the use of a starting plug, so that end scrap loss in the final ingot is avoided.

Another object is to provide a new and improved continuous casting" method by which the use of a starting .plug is avoided and end scrap loss in' the final ingot eliminated.

In carrying out the features of the present invention, there is provided a tubular mold furnace having its bottom initially closed by a start- This startingstool is provided with an indenture into which the molten metal roduced and. deposited in the furnace flows to orm an ingot projection. The retention 'ofthis ingot projection in the starting stool indentureafiords an effective anchorage between the stool and the bottom 'of the ingot, so that withdrawal of the ingot from the tubular mold furnace can be effected by the movement of the stool axially away from said furnace. The starting stool is section-' alized to permit its removal from the ingot at the'end of the operations.

The end section of the ingot having the stool anchoring conformation is of the same analysis and forms an integral part 0f,the rest of the ingot, and therefore can be worked with the rest oftheingot.

As another featureof' the present invention, the method'and apparatus of the present invention above referred to is employed in conjunction' with the electric fusion method of producing metals in which an electrode is submerged 1 in a protective layer of flux to create a metal fus ng'zone and metal ingredients are fed into this zone, fused therein and e then deposited below the flux-layenfiwhich may be of any suitable hollow shape, but which is shown in' the form of an upright cylindrical tube This mold I0 may be of suitable refractory material, or may be of metal such as copper hollowed as shown to form a jacket H for the circulation of a suitable cooling medium therethrough such as water.

During the preliminary stages of the metal producing and casting operations in the mold furnace 10, the lower end of this furnace is closed by a base,member I2 which serves not only as r a starting stool,-but also serves as a means by which the cast ingot A is gripped and pulled away from the mold furnace. For that purpose,

themember l2 comprises two semicircular ingot clamping segments -I3 releasably fastened together by any suitable means, as for example by bolts l5 passing through lugs N3 in the two segments. These stool segments l3 conjointly define a recess l8 with a bead indenture '20. The metal which is produced and deposited in this stool recess l8 forms an enlarged head 2| with a radially outwardly extending bead or projection 22. This bead conformation 22 on the cast ingot affords an effective grip or anchorage for thestarting stool I 2 as it is movedaway from the mold furnace III to cause withdrawal. of the cast ingot A from said mold furnace.

The starting stool segments l3 may be of suitable refractory material, or may be of metal such as copper hollowed to form a jacket 23 for the circulation of cooling water therethrough as shown.

The metal is produced and deposited in the mold furnace l0 and the starting stool l2- desirably by the use of 'a flux submerged electrode device which maybe of the general type shown in my. U. S. Patent No. 2,151,914fissued March" ,28, 1939, and No. 2,191,479, issued February 27, 1940. For that purpose, there may-be provided a consumable hollow electrode extending in I are fed at controlled rates to the gap between the end of said electrode and the pool'of molten metal 30 by suitable means, as for instance that shown in my Patent No. 2,191,479 above referred to. The hollow electrode 26 may be continuously shaped from a metal strip as shown in said patent.

I .If desired, the electrode 28 may be non-consumable, and all of the necessary metallic constituents to make up a metal of desired analysis may be fed in fluent or more solid form into the metal fusing zone created by the electrode.

The electrode 26 is submerged in a floating layer or blanket of flux 28 of any suitable composition which does not produce an objectionable'amount of gas under the influence of an electric discharge, and which has the required refining effect on the fused metal. Flux comprising silicates or components of silicates, such as manganese silicate, calcium silicate, aluminum ed, a. metal 2| in said starting stool is solidi-- fled and hardened to a sufllcient extent to afford a solid anchorage for said starting stool.

- During the ingot withdrawal operations, the furnace l0 may be shaken or revolved slowly with respect to the starting stool it to facilitate removal of the ingot A from said furnace.

The axial continuous movement of the starting stool l2 away from the mold furnace iii may be controlled at a rate whichis equal to or great.

er than the rate at which the metal is produced and deposited in the furnace W. This rate of silicate, glass and the like have been found suitable for this purpose. This flux layer 28 serves to refine the metal as it is produced, protect it against atmospheric contamination and insulate the metal against rapid heat loss. I

The electrode 26, the mold furnace I0 and the stool l2 are electrically connected in the same circuit to discharge current across the gap between the electrode 26 and the body of deposited molten-metal 30.

Any suitable means may b provided for continuously pulling the starting stool l2 away from the mold furnace ll). For example, the stool segments B may have dove-tail slide connections 32 to the upper end of a feed screw 33 moved axially through an axially fixed worm wheel 34 which is threaded on said feed screw and which is driven from a worm 35.

In the operation of the method illustrated in Fig. 1, at the start of operations, the stool l2 s is disposed in engagement with the lower end of the mold furnace Ill. The metal producing and depositing operations are initiated with the electrode 2'6near the bottom of the stool If in the presence of the flux 28. A quantity of the desired metal in the form of grindings or chips is placed in the bottom of stool l2 to protect the bottom wall of the stool from direct contact with the electric current discharge at the beginning of the operations. A quantity of the raw materials of the desired metal in granular form and in the proper proportions may be used for this purpose if preferred.

As the metal is produced and deposited. in the stool l2 and the mold l0, and the level of the molten metal rises, the electrode 26 is moved upwardly to maintain a gap of constant length between, the lower end of the electrode 26 and the upper level of the deposited molten metal 30. After the molten metal 30 has reached a predetermined level in the mold furnace III, the starting stool IZ-is moved axially and continuously away from the mold furnace Hi. When this axial movement of the starting stool I 2 is initiatmetal production may be controlled by regulating the rate of electrode feed and the rate of feed of the other metal constituents which may be delivered in fluent form into the fusing zone Instead of withdrawing the solidified metal from the furnace l0. continuously, this withdrawal may be effected by a step by step operation. For example, if a predetermined solid section of the ingot has been slowly withdrawn from the mold furnace, this ingot withdrawal is interrupted and the electrode 26 is lowered until its lower end is submerged in the flux 28 and spaced from the surface of the molten metal. The electric metal fusing and depositing operation is then continued to produce and deposit metal in the mold furnace, and thereby fill up the furnace space left vacant by the previous ingot withdrawal operation. During the gradual withdrawal of the ingot, the metal fusing and depositing operations need not be interrupted, but the electrode 28 may be made to mov in unison with the withdrawingingot, and the electric discharge through the gap may be continued during this withdrawal.

After the metal in the furnace it has been produced up to a predetermined level again, the movement of the starting stOOl I2 away from. the mold furnace I0 is resumed until another ingot section of predetermined length has been pulled out of said furnace; This step by step with-. drawal of the ingot is continued until an ingot of predetermined length has been produced.

As many changes ca'n be made in the above method and apparatus, and many apparently widely different embodiments of this invention can be made without departing [from thescope of the claims, it is intended that all matter contained in the above description or shown in 3 the accompanying drawing shall be intenpreted as illustrative and not in a limiting sense.

What is claimed is:

1. An ingot casting apparatus comprising an open ended tubular mold, a concave mold stool adapted to close the bottom end of said mold, means for moving said stool axially away from said mold, said stool having an ingot anchoring bead recess extending radially outwardly from its hollow and around the entire periphery of said hollow, said stool comprising two hollow walled complementary sections, means for circulating a cooling medium through each of said sections, means releasably securing said sections together to permit separation of said sections for removal of said sections from the' ingot, and means for depositing molten metal into said mold and said stool. V

2. An ingot casting apparatus comprising a hollow-walled, open-ended tubular mold, means .for circulating a, cooling medium through the hollow walls of said mold, a concave mold stool adapted to close the bottom end of said mold, said stool having an ingot anchoring bead recess extending radially outwardly from'its hollow and I said sections from the ingot end, electrode means adapted to deposit molten metal in said stool and mold beneath the surface of a protective blanket of flux, and means for. moving said stool away from said mold to withdraw metal from said mold as it solidifies. v

ROBERT K. HOPKINS.

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