US3556360A

US3556360A - Gas stopper for a ladle

Info

Publication number: US3556360A
Authority: US
Inventors: Thomas E Stelson
Original assignee: Nozzle Inc
Current assignee: Nozzle Inc
Priority date: 1969-01-15
Filing date: 1969-01-15
Publication date: 1971-01-19
Anticipated expiration: 1988-01-19
Also published as: LU60147A1; DE1962940A1; FR2028350A1; GB1222640A; BE744032A; NL7000436A

Abstract

A gas operated stopper for pouring molten metal from a ladle comprising a stationary nozzle seat having an opening therethrough, a movable nozzle positioned in the nozzle seat opening and having a cross section less than the cross section of the opening to form a gap therebetween and a gas operated piston assembly in which the cylinder is secured to the stationary nozzle seat and the piston is secured to the movable nozzle. Compressed air raises the piston and nozzle to remove an extended top section of the nozzle from a mating surface on the nozzle seat and thereby opening a series of inclined passageways leading to a vertically disposed passageway in the nozzle. An inert gas is introduced through the above-identified gap to lubricate the system and prevent molten metal from entering therein.

Description

United States; Patent [72] Inventor Thomas E. Stelson Pittsburgh, Pa. 211 Appl. No, 791,437 [22] Filed Jan. 15, 1969 [45] Patented Jan. 19, 1971 [73] Assignee Nozzle, Inc.

Pittsburgh, Pa.

[54] GAS STOPPER FOR A LADLE 14 Claims, 6 Drawing Figs.

[52] US. Cl 222/559, 164/254, 164/337 [51] Int. Cl 865d 47/99, B67d 3/02 [50] Field ol'Search 222/559, 571, 334; 221/102; 266/38; 164/254, 337

[56] References Cited UNITED STATES PATENTS 2,791,814 5/1957 Vi1lela...., 222/559 2,863,189 12/1958 Beck 3,354,939 11/1967 Calderon Primary Examiner-David M. Bockenek Attorney-Webb, Burden, Robinson & Webb 222/559UX 222/559X ABSTRACT: A gas operated stopper for pouring molten metal from a ladle comprising a stationary nozzle seat having an opening therethrough, a movable nozzle positioned in the nozzle seat opening and having a cross section less than the cross section of the opening to form a gap therebetween and a gas operated piston assembly in which the cylinder is secured to the stationary nozzle seat and the piston is secured to the movable nozzle. Compressed air raises the piston and nozzle to remove an extended top section of the nozzle from a mating surface on the nozzle seat and thereby opening a series of inclined passageways leading to a vertically disposed passageway in the nozzle. An inert gas is introduced through the above-identified gap to lubricate the system and prevent molten metal from entering therein.

PATENTEU JAN 1 9 |97| H v 556; 1360 saw 1 or 3 v INVENTOR. Thomas E. Ste/son y WMMM mum HIS ATTORNEYS PATENTEn JAN 1 a 1m:

SHEET 2 OF 3 INVENTOR. Thomas E. Stelson I N 104 ms ATTORNEYS PATENIED JAN) 9197:

SHEE'I 3 BF 3 R m m V W Thomas E. Sfelson BY u/LM M M i 1% HIS ATTORNEYS separate cap 18 is merely a choice of design based upon cost and ease of fabrication ofthe respective units.

The gas operated piston assembly 5 is positioned outside of ladle 2 beneath the ladle bottom 7 and is mounted to nozzle seat 3. The piston assembly 5 comprised of all metal parts, has an annular cylinder wall 24 having threads 25 at its upper end which cooperate with threaded recess 22 in the nozzle seat 3 to stationarily secure the assembly 5 thereto. The wall 24 which extends completely around seat opening 13 and nozzle 12 has an inwardly disposed flange 26 around its inner surface 27 which serves as the upper limiting position for the piston. The wall 24 has a lower section 28 extending perpendicular from the vertical section mounted to the seat 3 at the bottom thereof and toward the nozzle 12. Section 28 in turn has a downwardly extending section 39 perpendicular to section 28. The inner surface 27 of the wall 24 and the wall section 28 form a part of cylinder chamber 29. A metal piston 30 operates within the cylinder chamber 29. Piston 30 is comprised of an annular shaft 33 which extends around nozzle 12 and an annular arm 32 which extends from the top of piston shaft 33 to the inner surface 27 of wall 24. Shaft 33 completes the cylinder chamber 29 in which piston arm 32 acts as the piston head. The bottom portion of piston shaft 33 has threads 31 which cooperate with lower threads 23 of nozzle 12 to secure the piston 30 to the nozzle 12. The piston shaft 33 and arm 32 are dimensioned so that the end of outwardly extending arm 32 slides along inner surface 27 of wall 24 which forms the inner cylinder wall. The stroke of the piston is limited at its upper end by flange 26 of wall 24 and is limited at its lower end by the extending lower section 28 of wall 24. The piston shaft 33 slides against the downwardly extending wall section 39.

A threaded, compressed air inlet 34 positioned near the bottom of wall 24 leads into passageway 35 which extends completely through the lower section 28 of wall 24 and into the cylinder chamber 29. An adjustable needle valve 36 is positioned in passageway 35 and extends out of lower section 28 to control the air input into cylinder 29. Two sealing rings 37 are secured to arm 32 to prevent leakage of the compressed air in cylinder 29 as arm 32 slides along inner wall 27. Two similar sealing rings 38 are recessed in the end of extended wall section 39 to provide an adequate seal between section 39 and sliding piston shaft 33.

The piston shaft 33 has a vertical inert gas passageway 40 leading vertically through the bottom section of the piston shaft 33 and continuing as recess 41 along the surface of shaft 33 which faces nozzle 12. Gap between the nozzle 12 and nozzle seat 3 also extends downwardly between the piston shaft 33 and the nozzle 12. Therefore, passageway 40 which leads into recess 41 communicates with gap 45. Passageway 40 has inlet means 42 extending through the bottom of downwardly extending portion 33 of piston 30. A lock bolt 43 extends through downwardly extending wall portion 39 to lock the piston shaft 33 against wall 39 in the closed position when the ladle is being filled.

The operation of my gas stopper shown in FIG. 1 is as fol lows: while the ladle is being filled with molten metal, the nozzle is in the closed position, as shown in FIG. 4, for a slightly different embodiment of my invention. In the closed position, the bottom seating surface 21 of cap 18 is in intimate contact with eating lip 16 of nozzle seat 3. This completely shuts off passageways 19 from the molten metal in the ladle. The weight of the molten metal on cap 18, gravity acting on nozzle 12 and lock bolt 43 all insure that nozzle 12 remains in the closed position. After the ladle is filled and teeming is ready to commence, lock bolt 43 is loosened and compressed air is fed through passageway 35 into cylinder chamber 29. This compressed air forces piston arm 32 upward until it contacts lip 26 of wall 24. Since the lower portion of piston shaft 33 is connected to nozzle 12, the nozzle 12 also moves upwardly removing the bottom seating surface 21 of cap 18 from lip 16 and permitting the molten metal to flow through into passageways 19 and through nozzle opening 17.

Simultaneously with the opening of compressed air passageway 35, inert gas passageway 40 is opened. This causes the inert gas such as argon to flow upwardly into gap 45, The pressure of the inert gas is maintained sufficiently high to prevent any molten metal from entering gap 45. The inert gas then bubbles into the molten metal. If the inert gas system is operated when the nozzle 12 is in the closed position, the inert gas enters recess 44, the excess space about the lower surface of nozzle seat 3, and exerts pressure on the top of piston arm 32 to help maintain the nozzle assembly 4 in the closed position. 1

It will be recognized by those skilledin the art that the mating surface areas 21 and 16 of cap 18 and nozzle seat 3, respectively, in intimate contact with each other to keep gas stopper 1 in the closed position is much greater than the surface area between the mating surfaces of a standard nozzle and stopper head presently employed.

In addition, it can be seen that the inert gas such as argon passing through gap 45 acts as a lubricant to permit easy movement of nozzle 12. It is also recognized that bubbling an inert gas through molten metals such as steel has many beneficial effects such as purging the steel by acting as nucleation sites for removing other entrapped gases in the molten metal. The gap 45 also permits uninhibited expansion and contraction of the various members whose surfaces define the gap.

Another embodiment of my invention is shown in FIG. 4. The only modification in this embodiment is in the gas operated piston assembly. The cylinder chamber 53 is formed of four separate annular metal walls. The top ofchamber 53 is defined by annular shaped wall 46 which has threads 25' at its upper end to cooperate with recessed threaded section 22' of nozzle seat 3 to secure the cylinder chamber 53 to the nozzle seat 3. The annular

vertical walls

47 and 48 both of which are welded to wall 46 form the outer and inner sidewalls respectively of chamber 53. Base wall 49 which is welded to outer wall 47 forms the bottom of cylinder chamber 53. The inner wall 48 has its outer surface aligned with wall 46 and nozzle seat 3' to define the opening for the nozzle 12 and the resultant gap 45 The piston 30' has an additional surface of the chamber 53 to slide on, namely, inner wall 48 and therefore, additional seal rings 50 are positioned in wall 48 to maintain the adequate seal.

Threaded, compressed air inlet 34' extends through sidewall 47 and base wall 49 and leads into passageway 35' which exits into chamber 53 below piston arm 32'. A similar compressed air passageway 51 in wall 46 exits into chamber 53 above piston arm 32 from compressed air inlet 52 which extends through the upper part of wall 47 and wall 46. With this embodiment, the raising of the piston and nozzle is the same as the embodiment of FIG. 1. The lowering of the nozzle to the closed position, as shown in FIG. 4, however, is accomplished by entering compressed air through passageway 51 which forces piston arm 32', piston shaft 33 and nozzle 12' downwardly causing seating surface 21' of cap 18 to contact seating lip 16' of nozzle seat 3' and shut off passageways 19 from the molten metal in the ladle.

A further embodiment of my invention is shown in FIGS. 5 and 6. In this embodiment, the nozzle itself is stationary, and a refractory piston operating within a chamber in the nozzle wall opens and closes the passageways leading from the ladle into the central nozzle opening.

A refractory cap 60 is permanently positioned above the nozzle opening 61 of nozzle 62 by securing it within the ladle 2 on the ladle bottom. Cap 60 has annular sides 63 which act as the nozzle seat and which completely fill the annular nozzle well 64. Again, a cementitious refractory (not shown) can be rammed between sides 63 and nozzle well 64 to secure the block in place.

Nozzle 62 having a tubular wall 65 is positioned in the opening in the bottom of the ladle 2' and is held in place by both the nozzle plate 67 bolted to the bottom side 68 of the ladle 2' by bolts 69 and the nozzle seat sides 63. The passageway 61 of the nozzle 62 vertically extends completely therethrough.

Cap 60 has'three equally spaced passageways 71 leading through the cap to an opening 72 directly above the opening 61 of nozzle 62 and which is defined by the space between the convexly curved inner bottom surface 70 of cap 60 and upper surface 74 of nozzle 62. v

A vertically disposed annular-chamber 73 extends within the tubular wall 65 of nozzle 62 from upper nozzlesurface 74 to a 'point in the nozzle which is below the bottom side 68 of the ladle. A compressed inert gas inlet 75 and connecting passageway 76 communicates with the bottom of chamber 73. A second inert gas inlet 78 andconnecting passageway 79 communicate withchamber 73 about midway between its ends and just below the bottom side 68 of the ladle. An annular refractory piston 80 having a length substantially equal to the depth of chamber 73 is loosely fitted in chamber 73 to fonn a gap 77 therebetween. Piston 80 has a small recess 81 at its bottom end which communicates with passageway 76 and a second larger recess 82 which is intermediate the piston ends and communicates with passageway 79. The upper surface 83 of piston 80 is sloped toward nozzle passageway 61 to mate with the convex surface 70 of cap 60.

An inert gas such as argon is'entered into recess 81 through passageway'76..The gas forces piston 80 upward until the upper surface 83, of piston 80 contacts the convex surface 70 of cap 60. This completely shuts-off passageways 71 from space 72 and opening 61 in nozzle 62. Because of the gap. 77 between the nozzle chamber 73 and the piston 80, argon escapes along the sides of piston 80 and out into the molten metal entering through passageway 71. The pressure of the argon is sufficiently maintained to insure that no metal gets into the gap 77. To lower piston 80 and permit metal flow through passageways 7.1. argon isintroduced through passageway 79 into recess 82 simultaneously as the flow of argon is decreased from passageway 76. The increase and decrease of argon flow in the respective chambers is synchronized to maintain a sufficient flow of argon in the gap 77 to prevent any molten metal from getting g therein. As in the other embodiments, this argon escapes into the molten metal. l

'lclaim: l. A gas operated stopper for a pouring ladle comprising:

A. A noule seat having a central opening and adaptedto be secured inia nozzle well-of the ladle; v B. A nozzle assembly positioned within the opening in the nozzle seatandhaving a central opening therein, at least a portionof the nozzle assembly being movable into and outof contact with the nozzle seat;

C. Said nozzle assembly and s'aid'nozzle seat-being constructed and positioned to provide a passageway connecting the interior of the ladle and the central opening in the nozzle assembly when the movable portionof the nozzle assembly is out of contact with the nozzle seat to allow liquids to flow from the interior of the ladle, through the passageway and out the central opening in the nozzle assembly;

D. A gas actuated piston member associated with the nozzle assembly, said piston formingthe movable portion of the nonle assembly into and out of contact with the nozzle seat to open and close the passageway between them whereby the flow of liquids is regulated; and p E. A second passageway surrounding the movable portion of the nozzle assembly providing a channel for the flow of inert gas to lubricate said moving member.

2. A gas operated stopper for a pouring ladle comprising:

A. A nozzle seat adapted to be secured in a nozzle well of the ladle and having a central opening therethrough and a seating surface surrounding the central opening;

B. A movable nozzle assembly having:

l. a tubular body portion having a vertically disposed opening therethrough and positioned in the opening in the nonle seat and having cross section smaller than the opening to provide a gap between the seat and the body portion of the nozzle assembly;

2. a cap portion on top of the tubular body portion having a cross section larger than the cross section of the body portion and having a seating surface surrounding the body portion positioned to mate with the seating surface on the nozzle seat; and

3. at least one passageway extending through the wall of the tubular body portion below the seating surface of the cap portion into the vertically disposed opening;

C. A piston assembly having:

l. a cylinder secured to the nozzle seat and having a fluid passageway communicating therewith;

2. a piston mounted for movement within the cylinder and secured to the movable nozzle. fluid entering the cylinder through said fluid passageway raises the piston and nozzle, separating said seating surfaces and permitting liquid to flow from the ladle through the passageway in the tubular body portion of the nozzle and through the nozzle opening; and D. An inlet connecting with thegap for supplying inert gas thereto, said inert gas lubricating the system and preventing molten metal from entering therein. 2

3. The gas stopper of claim 2 wherein the cylinder has an outer surface parallel with the nozzle and axially aligned with a portion of the nozzle seat which defines the central opening to thereby longitudinally extend the gap between the body portion of the nozzle and the nozzle seat.

4. The gas stopper of claim 2 wherein the seating surface of the nozzle seat has araised lip extending upwardly therefrom to cooperate with the seating surface of the cap portion of the nozzle assembly.

5. The gas stopper of claim 2 wherein the cap portion is a separate refractory cap secured tothe upper section of the 6.- The gas passageway communicates with the cylinder at substantially the top thereof, whereby fluid forces the piston and connected nozzle downwardly so that the seating surface of the cap portion of the nozzle assembly mates with the seating surface of the nozzle seat.

7. The gas stopper of claim 2 wherein the cylinder has an upper threaded end which cooperates with threads in a recessed area in the bottom of the nozzle seat, said recessed area communicating with said gap, whereby gas enters said recessed area when the seating surfaces are mated to define a closed position to exert a pressure on the top of the piston to maintain said closed position. v

8. The gas stopper of claim 2 wherein the passageway extending through the wall of the tubular body portion is inclined to the vertically disposed opening in the tubular body portion.

9. The gas stopper of claim 2 wherein the cylinder is annularly disposed about the tubular body portion of the nozzle and the piston is annularly shaped for movement within the cylinder. K

10. The gas stopper of claim 3 wherein a piston shaft of the piston forms the outer surface of the cylinder which parallels the nozzle and is axially aligned with that portion of the nozzle seat defining the nozzle seat central opening.

11. The gas stopper of claim 10 wherein a lock bolt extends through a lower section of the cylinder and is adaptable to contacting the piston shaft to prevent movement of the piston in the cylinder.

12. The gas stopper of claim 10 wherein said gap connecting l. a centrally disposed passageway therethrough;

2. an annular chamber vertically disposed from the top surface of the nozzle into the tubular wall and about said centrally disposed opening; and

. a first and second gas passageway through the wall of the nonle, said first passageway communicating substantially at the bottom of said chamber and said second passageway communicating with said chamber between the ends thereof; and

C. An annular refractory piston loosely positioned in said chamber to form a gap therebetween said piston having an upper surface adapted to mate with an inner surface of the cap and a first and second recess. the first recess communicating with the first gas passageway and the second the cap is convexly shaped to mate with the upper surface of the piston.

Claims

1. A gas operated stopper for a pouring ladle comprising: A. A nozzle seat having a central opening and adapted to be secured in a nozzle well of the ladle; B. A nozzle assembly positioned within the opening in the nozzle seat and having a central opening therein, at least a portion of the nozzle assembly being movable into and out of contact with the nozzle seat; C. Said nozzle assembly and said nozzle seat being constructed and positioned to provide a passageway connecting the interior of the ladle and the central opening in the nozzle assembly when the movable portion of the nozzle assembly is out of contact with the nozzle seat to allow liquids to flow from the interior of the ladle, through the passageway and out the central opening in the nozzle assembly; D. A gas actuated piston member associated with the nozzle assembly, said piston forming the movable portion of the nozzle assembly into and out of contact with the nozzle seat to open and close the passageway between them whereby the flow of liquids is regulated; and E. A second passageway surrounding the movable portion of the nozzle assembly providing a channel for the flow of inert gas to lubricate said moving member.

2. A gas operated stopper for a pouring ladle comprising: A. A nozzle seat adapted to be secured in a nozzle well of the ladle and having a central opening therethrough and a seating surface surrounding the central opening; B. A movable nozzle assembly having:

2. a piston mounted for movement within the cylinder and secured to the movable nozzle, fluid entering the cylinder through said fluid passageway raises the piston and nozzle, separating said seating surfaces and permitting liquid to flow from the ladle through the passageway in the tubular body portion of the nozzle and through the nozzle opening; and D. An inlet connecting with the gap for supplying inert gas thereto, said inert gas lubricating the system and preventing molten metal from entering therein.

3. a first and second gas passageway through the wall of the nozzle, said first passageway communicating substantially at the bottom of said chamber and said second passageway communicating with said chamber between the ends thereof; and C. An annular refractory piston loosely positioned in said chamber to form a gap therebetween, said piston having an upper surface adapted to mate with an inner surface of the cap and a first and second recess, the first recess communicating with the first gas passageway and the second recess communicating with the second gas passageway, whereby gas entering the first passageway forces the piston upward to mate the piston top surface and the inner cap surface to close the passageway through the nozzle seat from the centrally disposed nozzle opening and gas entering the second passageway forces the piston downward opening said passageway through the nozzle seat, the gas from both of said passageways also exiting upwardly through the gap to prevent molten metal from entering therein.

3. at least one passageway extending through the wall of the tubular body portion below the seating surface of the cap portion into the vertically disposed opening; C. A piston assembly having:

4. The gas stopper of claim 2 wherein the seating surface of the nozzle seat has a raised lip extending upwardly therefrom to cooperate with the seating surface of the cap portion of the nozzle assembly.

5. The gas stopper of claim 2 wherein the cap portion is a separate refractory cap secured to the upper section of the nozzle.

6. The gas stopper of claim 2 wherein a second fluid passageway communicates with the cylinder at substantially the top thereof, whereby fluid forces the piston and connected nozzle downwardly so that the seating surface of the cap portion of the nozzle assembly mates with the seating surface of the nozzle seat.

7. The gas stopper of claim 2 wherein the cylinder has an upper threaded end which cooperates with threads in a recessed area in the bottom of the nozzle seat, said recessed area communicating with said gap, whereby gas enters said recessed area when the seating surfaces are mated to define a closed position to exert a pressure on the top of the piston to maintain said closed position.

9. The gas stopper of claim 2 wherein the cylinder is annularly disposed about the tubular body portion of the nozzle and the piston is annularly shaped for movement within the cylinder.

12. The gas stopper of claim 10 wherein said gap connecting inlet extends through the shaft of the piston.

13. A gas stopper for a ladle comprising: A. A nozzle seat having a central opening therethrough and stationarily secured in the ladle, said vertical opening axially aligned with an opening through the bottom of the ladle, said nozzle seat having a refractory cap positioned above the central opening and at least one passageway extending through said nozzle seat and communicating with said central opening; B. A tubular nozzle stationarily secured within the vertical opening in the nozzle seat, said nozzle having:

14. The gas stopper of claim 13 wherein the inner surface of the cap is convexly shaped to mate with the upper surface of the piston.