US3050793A - Molten metal distribution apparatus - Google Patents

Description

Aug. 28, 19.62 E. TRAGNER ETAL MOLTEN METAL DISTRIBUTION APPARATUS Filed May 5, 1961 INVENTORS. ER\CH TBABNER {E ROLF KU$TER, BY

THE/l? ATTOE/VEX V 3,050,793 MGLTEN METALDISTREUHGN APPARATUS Erich Trigner and Rolf Kiister, ingen/Hohentwiei, Germany, assignors to Aiuminium=industrie-Aktien-Gesell= schaft, Chippis, Switzerland, a joint-stock company of Switzerland Filed May 5, 1961, Ser. No. 198,050 Claims priority, appiicatien Germany May 25, 196i) 4 Claims. (31. 22--7) The invention relates to continuous or semicontinuous 7 metal casting, and relates more particularly to distributing means and methods for the molten metal that is subsequently solidified.

Semi-finished products made of aluminum or aluminum alloys, to which subsequently there is. imparted a decorative anodic oxydation or anodic polishing, require a high degree of fineness and uniformity of grain structure. While the specific degree of fineness may to a certain extent be influenced by the handling during the preparation.

of the metal grains, certain attempts have been made in the past to control the flow of liquid metal into the feeding head; in all of these attempts, however, the metal flowing into the metal bath was guided along straight paths which resulted in grain structures which were not sufficiently uniformly fine as desired for decorative anodic oxydation or anodic polishing.

The instant invention provides for improvements which include that a distribution is made with a distributor in which the depth of the sump in the continuous casting die or mold is kept small and wherein the molten metal receives an angular momentum before it flows into the metal bath.

It is accordingly among the principal objects of the invention to provide for a method and means to improve the conditions before solidification of moltenmetal, by controlling the flow of the liquid metal into the feeding head and to impart a pre-determined spinning movement to the liquid metal prior to its discharge into said feeding head.

It is another object of the invention to discharge molten metal into the metal bath in the form of several streams flowing in various directions.

It is a further object of the invention to impart an angular momentum to the molten metal flowing into a metal bath.

It is still a further object of the invention to provide for means that will impart such angular momentum to the flowing molten metal.

It is another object of the invention to provide means to keep the depth of the sump in the die during the flow at a small height.

Further objects and advantages of the invention will be set forth in part in the following specification and in part will be obvious therefrom without being specifically referred to, the same being realized and attained as pointed out in the claims hereof.

With the above and other objects of the invention in view, the invention consists in the novel methods, construction, arrangement and combination of various devices, elements and parts, as set forth in the claims hereof, certain embodiments of the same being illustrated in the accompanying drawings and described in the specification.

The foregoing and other objects of the invention will be best understood from the following description of one exemplification thereof, reference being had to the accompanying drawings, wherein:

tf is at I ice FIG. 1 is a fragmentary plan view' showing a distributor in a metal bath held in a continuous casting die or mold in accordance. with an embodiment of the invention; and

FIG. 2 is a fragmentary sectional view taken on the line 2-2 of FIG. 1.

In carrying the invention into effect in one of the embodiments which has been selected for illustration in the accompanying drawings and for description in this specific'ation, there is provided a distributor such as a bucket 1 that is held at one end of a balancing beam 3. The beam 3 carries at the other end an adjustably positionable counterbalance weight 4. To the beam 3 there is furthermore connected an arcuate rod 3a that carries float means such at two floats 2. The beam 3 includes a knife edge 5.

The bucket 1 is partially immersed in the bath of molten metal 6a that is held in the mold 6. A tapered metal discharge nozzle 7 is provided that extends vertically and has a substantially horizontal opening 70.

The assembly of the bucket 1, the beam 3, the Weight 4, and the floats 2 is supported by the floats 2 swimming on the surface of the metal bath 6a, and by the beam 3' resting with the knife edge 5 on the upper surface of the wallof the mold 6.

The operator, at the start of the casting, will adjust the weight 4 on the beam 3 to such a position thatthe bucket 1 floats on the surface of the metal bath 6a in a predetermined position below the discharge nozzle 7;

in this predetermined position the bottom 12 of the bucket 1 is disposed but for a small distance below the opening 70, thereby defining with the lower end of the nozzle 7 a circular vertical gap and guiding the molten metal to flow horizontally, through said gap, between the opening 7a and the bottom 12 of the bucket 1 after it leaves the nozzle opening 7a. The bucket regulates in a well-known manner the flow of the metal through the nozzle 7 in that in accordance with the variations in the heightof the level 9 of the metal bath 6a in the mold 6, the said gap is varied in height and thereby the flow through the opening 7a of the nozzle 7 is more or less restricted by the bucket 1.

The bucket 1 has upright slots 8 through which the metal pours out until it reaches a freezing zone near the sidewall of the mold 6. The slots 8 are preferably V- shaped, and extend throughout from the bottom 12 to the top edge of the sidewall 11 of the bucket 1; by this arrangement, the metal streams will exit from the bucket mainly in oblique upward direction out to the sump center.

In accordance with a preferred embodiment, the sidewall 11 of the bucket 1 is so arranged that the terminal surfaces ltia and 10b of the V-slots are inclined relative to the radial direction from the center of the buck bottom 12. By this arrangement, the portions of the sidewall 11 between the slots 8 are spirally ofi-set relative to the center of the bottom 12.

Due to this structure, there will be imparted to the molten metal exiting from the bucket 1 an angular momentum or spinning, as indicated by the arrow C in FIG. 1. This arrangement of the bucket permits an excellent utilization of the kinetic energy of the molten metal discharged by the nozzle 7, so that there is assured a strong movement of the molten metal in the feeding head.

The inner diameter A of the bucket bottom 12 is the same as, or only slightly larger than, the external outer diameter E of the bottom portion of the nozzle 7,.and the side wall 11 of the bucket 1 is tapered internally similar to the external taper of the nozzle 7.

In accordance with the invention, the molten metal flows through the slots 8 out of the bucket 1 in the direction towards the wall of the mold 6. Themetal flows out of the bucket in strong streams and causes a forceful v of ,spots or stripes.

'rnovem ent since the knead energy, of themoten metal f fiO Wi II g out Of the nOZ Z l e Tii OWingTO fhebldsefitdfihe bucket 1 relative to'the nozzle 7, preserved. The close fit on the otherlhand, promotes guiding of the bucket 1 floating on the metal bath 6a, V

It has been found that the aforesaid strong niovehient at the feeding head increases with increasing casting ispeed;the refinement of grain achieved thereby increases to an optimumvalue. Since, moreover, with the instant t bucket construction thejdepth'of the sump increases but .Very little with, increasing casting speed, the aforesaid optimum of the achieved quality of the cast metal is attaned at ahigh casting production.

. 7 Example 7 M the casting of round billets with a diameter of i 1 about 6 in. to about 7 1'n., a bucket 1 isused the bottom 12 of'which has a minimum diameter A of about 71 g in., which corresponds approximately. to the outer di- .ameter Eiof the nozzle 7.' 'Iheohtermost diameter B of the sidewall 11 of the bucket 1' is about 2% in, and the f. :height H of theihuclret about 1 in. The nozzle 7 has ,anexit diameter D of about 0.315 in." With such a dl-i. I amete'r D of the nozzle 7 there can'in the said arrangement be'cast-round billets ofabout 7 in; diameter at a 'lowering 'speed of from about 3 /2 to 4% in. per minute for the following aluminumfalloy and temperature: v aluminum alloy with from 0.4to 0.9 percent magnesium and from 0.3 to'.0.7.;percent silicon and "at a temperature of about 129-2? 'The resulting round billets are characterizedby uniform finegrain structure,and after: a

cles have neither'str'ipes nor spots;

press operation and following anodic oxydation the arti- Wewish it to be understood that We do not desire to I be limited to the exact details of construction; shown and described, for obvious modifications will occur to a person skilled in the art. i

Having thus described the invention, What we claim as new and desire to be secured by Latters Patent, is as follows l. A distributor, for use in connection with a molt'en metal bath in a walledfii'dlfrfor"continubufcasting and] V a nozzle having a substantially horizontal'discharge open-.

ing for the passage of molten metal tow-ardsaid bath; I said distributor comprising a bucket including a bottom t and a sidewall, support means, includingfloat' means adapted to be supported on said metal bath, and a balancing beam including a counter-balancingweightaanda balancing knife edge operable-to,rest on-'the mold wall, thereby supporting said bucket in a position wherein said bottom of the bucket is disposed a shortdistance be-t low the discharge opening of; said, nozzle} said buckethaving in the sidewalla series of upright slots for the discharge of molten metal from the bucket into said bath;

2. in adistributing' arrangement, the combination with 1' "a walled mold for a molten, metal bathand a (su'bstan-y- A tiallyfvertical discharge nozzle conveying moltenime tal towards said bath'and'comprisinga loweii portionof pregj determined circumference defiiiin'ga horizontal discharge plane, of abucketincludinga bottom and aisidewall 'slaid sidewall defining anI-internal orbit only slightly larger 5 than said circumference, supportrneans, includingafloat t meanssupportedjby said bath, anda'balancing-beairifimv f :cluding a counter-balancing"weight and-a balancing knife 1 edge operable to rest on the moldjwall, therebyl suspeii d' ingfsaid bucket infla position wherein "said .bottorhfoff' the bucket-is disposed a short distance below said dis charge plane of said nozzle, 's'aidjb'ucket having in the isidewall a series of upright'slots adapted for 'the dis icharge, 1 1

of molten metal'fro-mthe bueket'into said bath. I

3. In 'a distribpting arrangement, as claimed in claim 2, saidsidewall terminating in-a top edge, said slotsfbeing' saidslots having opposite surfaceslinclinedrelative to the radial direction from/the center of said bottonn' V-shap'ed,andextending' throughout frorn the lowermost. V

tothe topmost parts of said bucket v V d 4. In a distributing arrangemengas claimed'inc'l'aim 3,

V References'iCite-d inthe file of this patent UNITEDESTATES PA ENTS M "2,243,425 Junghans Y 'Q May 27, 194i ;-2,s1s,477 Short. New-18,1952,

I 2,876,509 V Gardner a Mar.f 10, 19,59

' 2,891,291 I Schnacke June23g, 1959 FOREIGN. PATENTS 750,709 Great Britain June 20, 1956' 819,818- Great Britain Sept. 9 -19 5 9- I

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