US2402498A - Apparatus for melting finely divided aluminum and alloys and other metals - Google Patents

Description

2 Sheets-Sheet 1 June 1946- N. KOHLHEPP.

APPARATUS FOR MELTING FINELY DIVIDED ALUMINUM AND ALLOYS AND OTHER METALS Filed May 25, 1943 June 18, 1946. N. KOHLHEPP 2,402,498

APPARATUS FOR MELTING FINELY DIVIDED ALUMINUM AND ALLOYS AND OTHER METALS Filed May 25, 1943 2 Sheets-Sheet 2 HHII.

Patented June 18, 1946 UNITED STATES PATENT OFFICE Q siz saarus Fon mama m nrvmnn AND METALS ALLOYS ANDOTHER Norman Kohlhepp, ummus, 1m. auignor .to

Reynolds Metals :(lompany, Richmond, Va.. a

corporation of Delaware Application any as, ms. Serial No. 4:8,354

3 Claims. '(Cl. 263-33) The object of thi invention is tov provide a f method for the re-melting of finely divided particles of metal, particularly aluminum and alloys thereof including scrap, sheets, lathe cuttings and borings, insuch manner as to largely overcome the problem of oxidation which is appurtenant to the re-melting of such finely divided portions of the aluminum and aluminum-alloys, the apparatus being automatic and of such nature that the customary manual or machine puddling is dispensed with, turbulent movements of the molten metal into which the material for re-meltchambers of the charging and agitation se'ction of the furnace.

Communicating with chamber of the charging and agitation section of the .furnacejbetween walls 6 is a conduit III.

This conduit passesthrough an aperture formed I in the arch l and at its top communicates with a box I I at the lower end of a hopper l2, thelatter communicating with the interior of the box.-

ing is injected being formed by gaseous generation, which gaseous generation is. so controlled as to have a physical eflect upon the molten metal and said re-melt material fed thereto.

The invention will be described with reference to the accompanying drawings, in which:

Figure l is a view in elevation and fragmentary in part; showing the lower portion of the front wall of a furnace, the forwardly projected scrapmelting unit at the base of the furnace and the scrap-feeding mechanism. a

Figure 2 is a vertical section on the linel-I,

Figure 8.

Figure 3 is a plan view, partly in'section, taken on the line 3-4. Figure 1.

Figure 4 is a transverse section on the line 4-4,

Figure 1, drawn to a larger scale.

Referring to the drawings, I have indicated at I the lower portion of the front wall of a furnace for containing a bath of molten aluminum or aluminum alloy into which the scrap or finely divided aluminum will be fed as raw stock or in molten conditiom Toward its base the front wall will be formed with an aperture for communication with a charging and agitation section. M

The charging and agitation section of the furnace shown in'the present embodiment consists of a trough-like body member 2 of refractory material and which may have an inner-casing 3 and an outermost casing 4, if desired. Lying immediately under the furnace wall I is a flat wall 5, the

lower face of which is inclined downwardly toward the front of member 2. Wall 5 may be supported directly upon the side walls of trough member 2 and upon spaced intermediate and longi- Mounted for reciprocation within the box-ls a charging ram of any suitable construction and adapted. when moved upwardly, to clear the intercommunicating space between the hopper l2 and box H so that the charging material will descend into the box and, alsoadapted on down-' ward movement, to press the charging material from the box and into the conduit III. In the present embodiment, the ram consists of 'a hollow rectangular member having side walls l3 and a bottom wall I, and at its top it carries spaced shearing blades l5. ,At its lower corners the boxlikeram carries angle irons ii, to takeup wear and to bear againstffsuitable abutments I! carried by the angular guides Is, the latter being supported on frame members l9 supported at their upper ends by brackets 20. The brackets 20 are carried by the main frame which consists of the vertical standards 2|, 21a: and the horizontal standards 22 and-'sub-frame members 222:.

The ram is reciprocated by a crank arm 25 and connecting rod 23, one rod being shown. The rod is pivotallymounted on a pin 24 carried by the ram, and is also pivotally mounted by a pin to crank 25 carried by a sprocket wheel 28 driven by chain 21 led over a sprocket wheel on a shaft 28 having suitable gear connections with a change-speed device 28 (diagrammatically shown in Figure 1) driven by motor 30.

It will be understood that the shearing blades I! may be fixed so that the upper end edge of the a ram may act as a co-shear. or be adapted for such action by the application of a separate shear 7 blade.

In the operation of my apparatus and method the hopper i2 is filled with the charging material, and it may be maintained filled by suitable-con- 'veying instrumentalities from a source of supply. The furnace will be provided with a bath of molten aluminum or aluminum alloy and the metal line in the furnace will be maintained above that in the charging and agitating section, a suitable metal line being indicated in Figure 1 as M.

Reciprocation of the ram will cause a constant or intermittent feed of the charging material into the interior of'the central 3 the centrai chamber of the charging and agitating section, said chamber being bounded by the wall 6, the base of the trough 2, the arch I and the wall 5, and also partially by the wall 8 as shown in Figure 2. The rate of feed may be regulated by the change-speed device 29 or by intermittently operating the feed ram, as desired.

The charging material will be fed under the level of the molten metal inthe furnace as may be seen in Figure 2. Due in part to the usual presence of impurities such as oil and grease with which the charging stock is coated, gases are generated in the charging and agitating section with each stroke of the ram, the primary generation being in the central section laterally bounded by the wall 6. a The pool of metal at the area P, Figure 1, is, of course, of less volume than that in the furnace and the generated gases constantly seek a passageway and hence develop greater turbulence in the .pool P and in the central chamber of the charging and agitating section. By such means very substantial movement of the molten metal and the charging stock undergoing melting is effected, enabling my method to wholly dispense with the customary mechanical puddling, and also to greatly reduce oxidation of the charging stock and to reduce heat losses.

It will be understood that the invention will be found useful in connection with metals in additionto aluminum and alloys thereof. For example, the invention is applicable to the melting of finely divided magnesium metal and its alloys under a mixture of fused chloride salts, which will greatly reduce the losses in the recovery of finely divided. magnesium under present methods. In such case the surface of the fused chloride salt becomes the equivalent of the metal line within the furnace as specified for aluminum. In other words, the aluminum metal line within the furnace then becomes a fused salt line, in which case the sub-surface metal line within the furnace could'be at the same level as the metal line within the charging and agitating section.

The claims are to be interpreted as applicable not only to aluminum and alloys but to metals generally.

Having described my invention. what I claim and desire to secure by Letters Patent is as follows:

1. In apparatus for melting finely divided aluminum and alloys, a. furnace adapted to maintain a mass of molten aluminum and having a lateral passageway-at its base, a charging and agitating furnace section projecting at the base area of the furnace and communicating with said passageway, said furnace section having top closure means for confining molten metal with the level thereof below the mass of molten aluminum within the furnace back of its said lateral passageway, and means above said top closure means for feeding said finely divided material into the molten metal within the charging and agitating furnace section and through said top closure means.

2. In apparatus for melting finely divided aluminum and alloys, a furnace adapted to maintain a mass of molten aluminum and having a lateral passageway at its base, a charging and agitating furnace section projecting at the base area of the furnace and divided by walls into a'central pool area and lateral pool area, said pool areas communicating at one end, said furnace section having top closure means for confining molten metal with the level thereof below a mass of molten aluminum within the furnace back of its said lateral passageway, and means above said top closure means for feeding said finely divided material into one of said pools of the charging and agitating furnace sectio'n.

3. Apparatus for melting finely divided aluminum alloys constructed in accordance with claim 1, in which the top closure means for the charging and agitating furnace section comprises an arch wall having an aperture therethrough for said feeding means, the arch extending trans- 40 versely of said furnace section whereby the depth of the molten metal ther in is major at the center of said furnace section and minor at thesides thereof.

NORMAN KOHLHEPP.

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