US3394928A - Combination oxygen lance clamp and descaling device - Google Patents

Description

R. A. WIEDL July 30, 1968 2 Sheets-Sheet 1 Filed Dec. 20, 1965 INVENTOR R- A. WIEDL July 30, 1968 COMBINATION OXYGEN LANCE CLAMP AND DESCALING DEVICE 2 Sheets-Sheet 2 Filed Dec. 20, 1965 INVENTOR Robe/*1 A. ll feal United States Patent 3,394,928 COMBINATION OXYGEN LANCE CLAMP AND DESCALING DEVICE Robert A. Wiedl, RD. 20, Rovaldi Ave., Bethlehem, Pa. 18015 Filed Dec. 20, 1965, Ser. No. 515,115 7 Claims. (Cl. 266-34) ABSTRACT OF THE DISCLOSURE An elongated tubular member such as an oxygen lance extending into a metallurgical furnace is supported against vibration during movement in opposite directions by coacting clamping members which are supported by guides for movement laterally into and out of supporting engagement with the tubular member. The clamping members pivot in opposite directions upon movement of the tubular member in opposite directions while it is engaged by the clamping members. The clamping members are moved into and out of engagement with the tubular member by activating means, such as hydraulic cylinders, which are arranged to accommodate pivoting of the clamping members.

This invention in general relates to apparatus for a basic oxygen furance and in particular to a novel means of supporting the oxygen lance in a basic oxygen furnace.

The refining of steel in the basic oxygen furnace is done by the removal of impurities from the molten metal bath in the furnace by contacting the surface of the molten metal bath with oxygen. The oxygen is supplied to the surface of the molten metal bath by means of an elongated water-cooled tube or lance. The lance is lowered downwardly into the open mouth of the furnace through the dust hood stop the furnace. The oxygen is subjected at high velocities, and the high velocity of the oxygen striking the surface of the molten metal bath causes violent reactions to occur between the oxygen and the elements in the molten metal bath, causing violent agitation of the molten metal bath. The slag and dense gases formed by the reactions between the oxygen and the elements in the molten metal bath are also in violent motion. Under the combined effects of the violent ejection of the oxygen from the lance tip and the turbulence of the gases in the converter, the elongated water-cooled lance is subjected to tangential forces and to radial forces which cause severe vibrations in the lance. It is therefore imperative that the lance be supported in some manner so as to minimize these induced vibrations. The lance must be supported so that many upward and downward movements of the lance during the refining of the molten metal bath can be done accurately and quickly. Also, the lance must be removed from the basic oxygen furnace from time to time during test periods and during charging of the furnace or pouring of the molten metal therefrom. It is therefore necessary that the supporting apparatus interfers as little as possible with the many movements of the lance during the operation of the furnace. During the blowing of the molten metal bath with oxygen, splashing occurs. As a result the lance tip becomes encrusted with slag and/or steel. It is important that this accumulation of slag and/or steel be removed from time to time to prevent the lance tip from becoming blocked.

Heretofore, the standard apparatus for positioning the lance in the furnace consisted of a wire rope hoisting device and a hood clamp, or the lance was supported on a structural steel tower having extending framework from which a wire rope sling was used to raise and lower the lance, or the lance was supported by a structural steel framework mounted on a vertically movable dolly. The

3,394,928 Patented July 30, 1968 "Ice wire rope hoisting device lowered the lance into the basic oxygen furnace the required distance, and a clamping arrangement was placed around the lance to prevent excessive vibrations of the lance. Since it was necessary to change the position of the lance frequently during the refining of the molten metal bath, it was necessary to remove the clamp from around the lance. Because the lance was not supported during the positioning period, the velocity of the oxygen had to be reduced to prevent dangerous vibration of the lance. This resulted in lost time and decreased efiiciency of operation. Also, there was no means provided toremove the accumulation of slag and/or steel splashing on the lance tip.

Both the structural steel tower and movable dolly arrangements were expensive and bulky. The tower, which supported the lance or the dolly, had to be located a distance from the basic oxygen converter, thus taking up valuable space in the shop.

It is therefore an object of this invention to provide inexpensive novel means for supporting the lance to prevent undue vibrations thereof.

It is another object of this invention to provide means to remove the accumulated slag and/or steel splashings from the lance tip.

I have discovered that these and other objects can be attained by providing a clamp having a pair of movable clamping forks attached to an activating means which urges the clamping forks into contact with the lance. The apparatus is designed so that it may move pivotally at any of three points thus allowing the lance to move while being held by the movable clamping forks.

FIG. 1 is a general view of a basic oxygen furnace installation.

FIG. 2 is a view in elevation of the clamping apparatus.

FIG. 3 is a plan view of the clamping apparatus in the clamped position.

FIG. 4 shows the clamping apparatus in the clamped position when the oxygen lance has moved in a downwardly direction when engaged by the clamping apparatus.

FIG. 5 shows the clamping apparatus in the clamped position when the oxygen lance has moved in an upwardly direction when engaged by the clamping apparatus.

Referring now to FIG. 1, the apparatus of the invention includes a basic oxygen furnace shown generally at 10, a hood 11 atop the basic oxygen furnace to remove gases and fumes therefrom, the oxygen lance 30 extending downwardly through the hood 11 into the basic oxygen furnace, and a clamping apparatus shown generally at 12 supported on the hood 11 by a metallic framework 13.

As shown in FIG. 3, the clamping apparatus includes two identical coacting movable clamping forks, each fork being provided with individual activating means. Since each of the forks and activating means are identical, only the left half of clamping apparatus will be described.

The clamping fork 18 is a generally rectangular fiat metallic member having a bifurcated rear portion 18a and an enlarged generally arcuate forward portion 29 which engages and holds the depending oxygen lance. The arcuate surface 29 of the fork 18 which engages the oxygen lance 30 has the same radius of curavture as the water jacket of the oxygen lance. Attached to and depending downwardly from the underside or surface of the forward portion of the fork 18 are a plurality of generally triangularly- shaped teeth 29a and 29b. The fabricated rear portion 18a of the fork is provided with holes 20 and 20a through which a metallic pin 19 is passed to attach the forward portion of the activating means to the fork 18. The fork 18 rests in and is guided in a generally horizontal straight line movement by a metallic channel 22. The metallic channel 22 is supported by a metallic superstructure 25 and 26. The guide channel 22 is two metallic brackets 27b and-27c welded to the side panels 22a. The said brackets 27]; and 270 are provided with holes through which safety lock pin 28 may be passed. A safety lock pin 28 is inserted into the hole 28a extending through the rear portion of the fork 18.

The rear portion of the guide channel 22 is supported atop the duct hood 11 by a metallic pin 23 extending through a metallic pipe 24 welded to the metallic angle 25. Attaching the guide channel 22 to the superstructure in this manner allows the forward portion of the guide channel to pivot generally upwardly with the pin 23 acting as a fixed pivot point. The forward portion of the guide channel 22 rests on and is supported by the metallic structural member 26.

The activating means includes a piston rod 17 having an eye 21 in its forward portion which fits loosely into the bifurcated rear portion of the fork 18. A metallic pin 19 inserted into the holes 20 and 20a in the bifurcated rear portion 18a of the fork 18 and passing through the eye 21 in the forward portion of the piston rod 17 fixedly attaches the said piston rod 17 to the fork 18. The fork 18 may pivot with respect to the piston rod 17 around pin 19. The rear portion of the piston rod 17 is attached to a hydraulic cylinder 15. The hydraulic cylinder is supported by a metallic superstructure 13 secured to the top of the dust hood over the basic oxygen furnace. The rear portion of the hydraulic cylinder 15 is provided with a yoke 15a which fits on either side of bracket 14 which is fixedly attached to the supporting metallic superstructure 13. A pin 16 extends through holes in the yoke 15a of the hydraulic cylinder 15 and through a hole in the bracket 14 to fixedly pivotally attach the hydraulic cylinder 15 to the bracket 14.

In operation, after the lance is in position in the basic oxygen furnace, pressure is applied to the piston rods 17 by the fluid in the hydraulic cylinders 15 thus pushing the forks 18 toward the lance so that the arcuate faces 29 of the forks 18 engage the lance. The forks 18 must hold the lance 'with a pressure sufficient to prevent excessive vibration of the lance during the blowing periods and insufficient to damage the lance. This pressure must be distributed evenly around the periphery of the lance. Therefore, the forks 18 must contact the lance at the same time and with equal pressure. For this reason, the activating means are connected to a common source of power (not shown). To prevent the forks 18 from being moved forwardly an excessive distance, safety pins 28 are inserted into the holes 28a in the rear portion of the fork 18. The safety pins 28 will engage the upright angles 27 and 27a thereby preventing any forward motion of the forks 18 toward the lance. The upright angles 27 and 27a prevent any undue sideway movement of the forks 18 during the operation as explained later.

As shown in FIG. 4, a downward movement of the lance while it is engaged by the arcuate faces 29 of the forks 18 will cause the forward portions of the forks 18 to move in a generally vertically downward direction. As seen in FIGURE 4, the forks 18 pivot on the front edges of the guide channels 22. The downward movement of the forward portions of the forks 18 results in their rear portions being moved in a generally vertically upward direction. Since the bifurcated rear portions 18a of the forks 18 are attached to the forward portions of the piston rods 17 by pins-19, the forward portions of the piston rods 17 will also move in a generally vertically upward direction. The pins 19 may be defined as floating pivot pins since they can move in a generally vertically upward direction with the forward portions of the piston rods 17 and the bifurcated rear portions 18a of the forks 18. The forward portions of the hydraulic cylinders 15 will also move in a generally vertically upward direction but the rear portions of the hydraulic cylinders 15 are fixedly pivotally attached to the metallic structure 13 and cannot move except pivotally. In essence, the clamping devices will bridge, thus preventing undue damage to the oxygen lance and preventing damage to the clamping devices themselves. If the lance should be raised as shown in FIG. 5, 'while being engaged by the arcuate faces 29 of the forks 18, the forks 18 will pivot on floating pivot pins 19 allowing the forward ends of the forks 18 to be raised.

When repair work is necessary on the hood atop the furnace or on the clamping apparatus, the forks 18 are retracted a distance .so that safety lock pins 28 may be inserted in the holes in the brackets 27b and 27c and in holes 28a thereby locking the forks 18 at the rear of the guide channels 22.

While I have shown and described the preferred embodiment of the invention in the foregoing disclosure, it will be understood that the invention may be practiced in other forms within the scope of the following claims.

I claim:

1. An apparatus in combination with a metallurgical furnace to engage an elongated tubular member extending downwardly therein, said apparatus comprising a pair of coacting individually movable clamping forks, activating means having their forward portions pivotally connected to the rear portions of said clamping forks to move the said clamping forks in a generally horizontal direction to engage said elongated tubular member, the rear portions of said activating means being fixedly pivotally attached to a supporting structure, means to guide the said clamping devices in a generally horizontal direction to engage said elongated tubular member, the rear portions of said clamping forks and the forward portions of the said activating means being movable in a generally upward direction and the forward portions of said clamping forks being movable in a generally downward direction for downward movement of said tubular member while it is engaged by said forks.

2. An apparatus as claimed in claim 1 in which the activating means is a hydraulic cylinder and a piston rod.

3. Apparatus in combination with a metallurgical furnace to engage an elongated tubular member extending therein, said apparatus comprising a pair of individually movable coacting clamping forks, the rear portions of each of the said clamping forks being connected to the forward portions of piston rods, the rear portions of said piston rods being inserted into hydraulic cylinders, said hydraulic cylinders and piston rods being activated to move the said clamping forks in a generally horizontal direction to engage the said elongated tubular member, the rear portions of said hydraulic cylinders being fixedly pivotally attached to a supporting structure, the forward portions of said piston rods being pivotally attached to the rear portions of the said clamping forks, said forward portions of said piston rods and rear portions of said clamping forks being movable in a generally vertical direction and the forward portions of said clamping forks also being movable in a generally vertical direction for general vertical movement of said tubular member in opposite directions while it is engaged by said forks, guide channels in which each of the said clamping forks are mounted, and a pair of angle guides fixedly attached in an upright position to the guide channels.

4. Apparatus as set forth in claim 3, together with stop means carried by said forks into engagement with said angle guides upon predetermined movement of said forks toward said tubular member.

5. In combination with a metallurgical furnace and an elongated tubular member extending therein, means supporting said member against vibration during movement of said member in opposite directions along the axis thereof comprising coacting clamping members, guide means supporting said clamping members for movement laterally of said axis into and out of supporting engagement with said tubular member, said clamping members pivoting in opposite directions upon movement of said tubular member in opposite directions along said axis while it is engaged by said clamping members, and activating means for moving said clamping members into and out of engagement with said tubular member, said activating means accommodating such pivoting of said clamping members.

6. The combination of claim 5, wherein said activating means comprise fluid motors of the piston-cylinder type mounted for pivoting with said clamping members.

7. The combination set forth in claim 5, wherein said clamping members have arcuate surfaces engaging and generally conforming to the curvature of said tubular member.

References Cited UNITED STATES PATENTS 2,518,086 8/1950 Snorer 269-32 3,027,155 3/1962 Paterson 26932 FOREIGN PATENTS 220,176 3/1962 Austria. 1,174,344 7/1964 Germany.

10 I. SPENCER OVERHOLSER, Primary Examiner.

E. MAR, Assistant Examiner.

Images