US1920300A - Teeming nozzle - Google Patents

Description

Aug. 1, 1933. A. J. GES.EL ET AL TEEMING NOZ ZLE Filwd Dec. 21, 1929 Vin T031 ATTO/f/VIYX Patented Aug. 1, 1933 PATENT oFFIcE TEEMING NOZZLE Albert J. Gesel and William M. Murray,

Buifalo, N. Y.

Application December 21, 192a. Serial No. 415,629

12 Claims. (01. 2H4.)

This invention relates to improvements in teeming nozzles for use in discharging molten iron or steel from a ladle or other container to molds, and to methods of teeming.

The objects of this invention are to provide a teeming nozzle having a distributing chamber formed therein which is shaped to prevent swirling of the metal flowing through the nozzle; also to provide a nozzle of this kind with a hardened tip in the distributing chamber to resist washing away of the lower portion of the nozzle; also to provide a nozzle of this kind with a weakened portion at which the nozzle can be broken away to facilitate removal of the metal in casethe e cools and solidifies within the nozzle or at its entrance; also to provide a nozzle of this kind which is designed so that it can supply the molten metal to the ingots at a substantially uniform velocity, in spite of decrease in head of the metal in the ladle or container after it is partly teemed; also to so construct the distributing chamber in the nozzle, that the metal will now readily into the various discharge passages of the nozzle; also to provide a nozzle of this kind in which the metal is fed to the ingot mold in a series of streams whichare brought together into substantially a single stream to reduce the amount of splashing when the metal strikes the stool or base of the mold; also.to provide an improved method of teeming in accordance with which a plurality of streams or jets of metal are discharged from the nozzle at an angle to form a substantially single stream as the metal strikes the stool at the bottom of the ingot mold; also to improve the construction of teeming nozzles and methods of teeming in other respects hereinafter specified. In the accompanying'drawing:

Fig. l is a sectionalelevation of a portion of a 49 ladle, having applied thereto a teeming nozzle embodying this invention, and showing an ingot mold into which the molten metal is discharged from the ladle through the nozzle;

2 is a similar sectional view of the teeming nozzle, on an enlarged scale, and detached from the ladle;

Fig. 3 is a sectional plan view thereof, on line 3-3, Fig. 2; and

Fig, 4 is a fragmentary sectional elevation thereof, on line 4-4, Fig. 3.

Teeming nozzles embodying our invention may be employed in connection with a ladle or con- 1 tainer. of any suitable or desired kind or construction. By way of illustration, a ladle of the kind frequently used is shown. which includes 7 of the ladle.

an outer steel shell 6 having a 7 of clay fire brick or other suitable refractory material, the ladle also being equipped with the usual stopper 8 for controlling the flow of metal from the ladle.

A represents the teeming nozzle embodying this invention, and which is suitably secured in the bottom of the ladle by means of a nozzle retaining plate 9, which may be secured in any suitable manner to the steel shell 6 of the ladle. g5

10 represents packing of refractory material which forms a tight joint between the outer surface of the nozzle-and the refractory lining The nozzle is supported on the plates '9 by means of an annular shoulder 1i fm formed on the nozzle at a distance below the top edge thereof, so that the nozzlecan be placed into its operative position by inserting the lower end thereof, through the opening in the retaining plate 9, which lower end then extends below the bottom of the ladle. A ladle of any other construction may be employed, if desired.

The upper portion of the nozzle above the shoulder 11 is preferably made slightly tapering downwardly to facilitate removal of the nozzle from so the ladle. I

The nozzle A is of one piece construction and made of refractory material and is substantially cylindrical in shape,.and is provided in; the upper portion thereof with a central downwardly extending passage 14, the upper portion of which is bell-mouthed or flared at 15 to cooperate with the lower end of the stopper 8 to interrupt the flow of molten metal through the nozzle. The passage 14 is preferably tapered from the upper portion to thereof to the part 16, which is of smallegt diameter.

The lower end of the passage 14 terminates in a distributing or velocity reducing cber 1?, which is substantially of the-shape of a frustum of a pyramid, and the lower .end of this chamber is provided with discharge passages 18 which terminate at the lower end of the nozzle and through which the metal may now to the ingot mold B. Consequently, the lower portion of the chamber 10H) 17 is approximately square in cross section in the particular construction shown, and the side walls of the chamber are formed of a plurality of flat surfaces. The shape of the chamber stops the swirling motion of the molten metal passing through it, which motion would interfere with the proper feeding of the molten metal to the discharge passages 18. In addition to this it will prevent any of the molten metal from emerging from the discharge passages 18 in the form of a spray onto the sides of the molds. Any spray from the discharge passages or splash of metal resulting from the impinging of the stream of metal onthe base or stool 20 of theingot mold would result in the depositing of particles or globules of metal on the cold walls of the ingot mold B, which particles or globules very rapidly become chilled. The outer surfaces of these particles become quickly oxidized. As the level of the metal in the mold rises, these oxidized particles of globules do not combine with the mass of metal, but retain their unity. If these particles or globules later are not removed from the ingot by a comparatively expensive chipping or grinding operation, then these particles, during the rolling or other processing of the steel, may fall out or cause slivers or scabs on the surface of the finished or rolled products, thus seriously depreciating the value of these products. It is,

therefore, very desirable to prevent, as far as possible, the forming of any spray or the splashing of the metal during the teeming of the'ingots.

In order to reduce as much as possible the splashing of the metal when it strikes the stool or base 20 of the ingot mold, the teeming nozzle is so designed that the cross sectional area of the passage 14 of the nozzle is less than the combined cross sectional areas of the several discharge passages 18 of the nozzle. Also the discharge passages 18 are arranged out of alinement with the passage 14 leading into the distributing chamber 17, so that the stream of metal entering the distributing chamber 17 strikes the bottom of the. chamber, and then flows sidewise and downward toward the discharge openings 18. Because of the fact that the sum of the cross sectional areas of the several discharge passages 18 is greater than the cross sectional area of the inlet passage 14, the velocity of the metal leaving the chamber 1'? will be less than that of the metal entering the chamber, so that splashing of the metal against the sides of the mold is materially reduced. In other words, the metal. enters the chamber 1'7 under pressure of the head of metal in the ladle or container, but'this pressure is destroyed in the chamber 17 so that the metal flows through the discharge passages 18 with less pressure and velocity.

In order to prevent excessive wear or washing away of the nozzle during the teeming of the metal, the, middle portion of the chamber 17 in the nozzle is preferably reinforced in any suitable manner, for example, by means of a hardened cap or tip 22, which may, for example, be made of magnesite clay or any special material found suitable for the purpose and the upper surface of which is preferably convexly rounded and extends above the inlet openings of the discharge passages lh, so that the metal striking this cap 22 will be readily deflected laterally into the dis charge passages. This insert 22 may be provided witha dove-tailed recess 23 in the lower face thereof, so that this insert is firmly secured to or bonded with the material of the nozzle. Other means for securing the cup or tip 22 to the nozzle may be employed if desired.

In the particular construction shown, the portion of the base of the distributing chamber 1'7 between the discharge passages 18 is preferably arch shaped, as indicated at 24, so that these portions of the base slope toward the discharge passages 18, thus facilitating the flow of metal from the distributing chamber into the discharge passages 18.

'In accordance with this invention. the downtom'of the mold. In this manner, the splashing of the metal against the sides of the ingot mold will be further reduced, while, when the upper portion of the ingot mold is being filled, the streams will enter the molten metal in the mold as separate streams, thus reducing the extent to which air bubbles, gases and non-metallic substances are carried downwardly into the molten metal, so that the ingots thus formed are more free from air holes, gas and non-metallic substances, than when a single stream of comparatively high velocity is discharged into the mold; The velocity of the metal flowing into the chamber 17 is greatest when the ladle is completely filled, due to the head of the metal in the ladle, and as the ladle becomes more nearly emptied, this velocity, due to pressure is reduced. By forming the inlet passage 14 of the nozzle, as shown, with a portion 16 of reduced cross section near the lower end thereof, the decrease in velocity, due to pressure, is compensated for by the washing or wearing away of the'material of the nozzle by the metal, so that the portion 16 of the passage 14 increases in diameter as the head of the metal in the ladle decreases, this diameter being greatest when the ladle is nearly empty, thus allowing a larger stream of metal at lower velocity to enter the distributing chamber 17, so that the rate of flow of metal discharged through the passages 18 will be substantially the same whether the ladle is full or nearly empty.

It sometimes happens that the metal willfreeze or solidify in the nozzle before the ladle is completely empty, and the nozzle described has been designed to facilitate the emptying of the ladle under such circumstances. For this pur pose, the nozzle is provided below the shoulder 11 thereof, with an inwardly extending groove or recess 25, which weakens the nozzle at this point, so that in 'case of freezing of the metal in the nozzle or at-its entrance, the nozzle can be easily broken at the weakened portion or groove 25 by striking the lower portion of the nozzle with a sledge hammer, whereupon an acetylene or other flame may be directed upwardly into the passage 14 to again melt the frozen or solidified metal, to permit the ladle to be drained.

In accordance with our improved process, the

molten metal is first conductedinto the swirl preventing chamber of the nozzle by means of a passage of smaller cross sectional area than the combined cross sectional areas of the discharge passages from this chamber, so that the velocity of the metal leaving the nozzle is considerably less than that of the metal enteringthe nozzle. The discharge passages 18 are arranged to converge downwardly toward each other and form substantiallya single stream at the lower portion of the ingot mold. At the upper portions of the mold, the streams are separated so that the chances of entrapping air bubbles, gas and nonmetallic substances in the upper portion of the mold are considerably reduced.

An important feature of the nozzle embodying this invention is that the supporting means for the nozzle which include the annular shoulder 11 are arranged above the bottom of the chamber 17 within the nozzle. This chamber, being 01' 5 considerable size, produces the minimum cross sectional area of the nozzle at a point approximately at the bottom of the chamber, which is well below the supporting means for the nozzle. Consequently even if the weakening groove 25 is .omitted, the nozzle can be broken by striking a lower part, and the break will occur in such a manner as to expose the chamber 17. This makes it possible to apply any suitable means, such as a flame, to the chamber 17 and passage 14 to remove solidified metal and thus permit the ladle or container to be drained.

We claim: 4

1. A teeming nozzle having a swirl preventing chamber in the intermediate portion thereof, a passage leading from the upper end of the nozzle into the swirl preventing chamber, and passages from the swirl preventing chamber to the lower end of the nozzle, said swirl preventing chamber being of non-circular cross section to resist the tendency of the metal to swirl in said chamber.

2. A teeming nozzle having a swirl preventing chamber in the intermediate portion thereof, a passage leading from the upper end of the nozzle into the swirl preventing chamber, and passages from the swirl preventing chamber to the lower end of the nozzle, the walls of the swirl preventing chamber being formed of substantially fiat surfaces to prevent swirling of liquid in said chamber.

' 3. A teeming nozzle having a swirl preventing chamber in the intermediate portion thereof, a passage leading from the upper end of the nozzle into said chamber, and passages leading from said chamber to the lower end of the nozzle, said swirl preventing chamber being of substantially frusto-pyramidal shape to prevent swirling of liquid therein.

4. A teeming nozzle having an inlet passage leading downwardly from the top thereof, a distributing chamber at the lower end of said inlet passage, discharge passages leading downwardly from said distributing chamber and out of alinement with said inlet passage, and a hard cap provided in the bottom of said distributing chamber in alinement with said inlet passage and against which molten metal impinges and is passed to said discharge passages of said distributing chamber.

5. A teeming nozzle having an inlet passage leading downwardly from the top thereof, a distributing chamber at the lower end of said inlet passage. discharge passages leading downwardly from said distributing chamber and out of alinement with said inlet passage, and a cap of hard material in the bottom of said distributing chamber in alinement with said inlet passage to resist wear of molten metal impinging against the bottom of said distributing chamber, said cap being convexly rounded to guide the molten metal impinging thereon toward said discharge passages.

6. A teeming nozzle having an inlet passage leading downwardly from the top thereof, a distributing chamber at the lower end of said inlet passage, and discharge passages leading downwardly from said distributing chamber, said nozzle being of reduced cross sectional area along a substantially horizontal plane extending through said distributing chamber to facilitate breaking the nozzle along said plane, and a nozzle retaining member engaging said nozzle only above the portion of reduced cross section thereof, to permit said nozzle to be broken off at said portion of reduced cross section below said retaining member.

7. A teeming nozzle having an inlet passage leading downwardly from the top thereof, a distributing chamber at the lower end of said inlet passage, and discharge passages leading downwardly from said distributing chamber, an annular groove extending inwardly from the outer Wall of said nozzle above the base of said distributing chamber to facilitate the breaking of the nozzle at said groove and an annular shoulder on the outer surface of said nozzle and arranged above said groove, for retaining said nozzle in operative position, to facilitate the breaking of said nozzle below said shoulder.

8. A teeming nozzle having a central distributing chamber, discharge passages leading from said distributing chamber, and an inlet passage leading to said distributing chamber, said inlet passage having a bell-mouthed upper end and being tapered downwardly from the lower end of said bell-mouth and of smallest cross sectional area at the lower end thereof, to facilitate the enlarging of the passage by the molten metal while the same flows through said passage.

9. A teeming nozzle for use on a ladle, said nozzle having a central distributing chamber, discharge passages leading from said distributing chamber, and an inlet passage leading to said distributing chamber, said inlet passage having a flaring upper end which converges into a tapering passage having a greater diameter at the upper portion thereof adjacent to said flaring portion than at the lower portion thereof adjacent to said distributing chamber, to facilitate enlargingof said passage as the head of metal in the ladle decreases.

10. A nozzle for teeming molten metal from a container, said nozzle having a shoulder formed on the exterior thereof, means secured to said container for supporting said nozzle on said container, said nozzle having a portion which extends below said supporting means, a distributing chamber formed in the interior thereof and having an inlet passage leading from the upper end of said nozzle to said chamber, and discharge passages leading from said chamber to the lower end of said nozzle, said chamber extending below said supporting means and producing a cross section of reduced area below said supporting means to facilitate breaking said nozzle above the bottom of said chamber.

. 11. A nozzle for teeming molten metal from a container to a mold, said nozzle having a shoulder on the outer surface thereof, means engaging said shoulder for supporting the nozzle on the container and the distributing chamber within said nozzle extending below said supporting means, and passages in said-nozzle leading to and from said distributing chamber.

12. A nozzle for teeming molten metal from a container to a mold, said nozzle having passages therethrough for the metal and an enlarged chamber, and means for supporting said nozzle on said container and having its lower end terminating above the bottom of said chamber, so that the lower portion of said nozzle may be broken below said supporting means and above the bottom of said chamber to render said chamber accessible.

ALBERT J GESEL. WILLIAM M. MURRAY.

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