TILTABLE LADLE ASSEMBLY

Abstract: A tiltable ladle for molten metals, having a cover (11) and a suspension frame comprising two lifting arms (5, 6) rotatably connected to trunnions (7, 8) fixed to the outside wall of the ladle (1) and a horizontal beam (9) above the ladle equipped with a hook (10). The top of the ladle and the ladle cover are formed as segments of a cylinder, which have a common axis. The common axis of these cylinder segments may coincide with the pivotal axis of the ladle (1) or may be spaced from it. The cover (11) is affixed to the suspension frame.

Description: The present invention relates to a tiltable ladle for molten metals and a cover for such a ladle. Numerous benefits are available when processing molten metals, if covers are used on the ladles or other molten metal containment and treatment vessels. Where covers are used, there are frequently problems associated with the mechanics of opening and closing the cover to allow metal charging, slag removal etc. These problems can include fouling the mechanics due to metal or slag splashing, time delays in opening and closing the cover, metal spillage if the cover mechanics are rough, and labour intensive operations. It is an object of the present invention to provide a ladle and cover which reduces the above problems and in which the cover can be opened and closed automatically when required and also in which the design of the ladle and the cover is simple and reliable. According to the invention, there is provided a tiltable ladle assembly comprising a ladle, a cover and a suspension frame, the ladle being pivotally supported by the suspension frame, characterised in that the top of the ladle and the ladle cover are formed as segments of a cylinder, having a common axis, and the cover is affixed to the suspension frame. In one form, the common axis of the cylindrical segments coincides with the pivotal axis of the ladle. Preferably, the cover is affixed to the suspension frame in such a way that there is a gap between the cover and the ladle. In a preferred form, therefore, the present invention may provide a tiltable ladle having a cover and a suspension frame, the suspension frame comprising two lifting arms rotatably connected to trunnions affixed to the outside of the wall of the ladle and a horizontal beam above the ladle equipped with a hook, and in which the top of the ladle and the ladle cover are formed as segments of a cylinder, the focal axis of these cylinder segments being the pivotal axis of the ladle, and in which the cover is affixed to the suspension frame. Alternatively, the common axis of these cylindrical segments is spaced at one side of, above, or below the pivot axis of the ladle. Preferably, then, the cover is affixed to the suspension frame in such a way that the cover closes the ladle when the ladle and the suspension arms are in a vertical position. Preferably, the suspension frame includes two lifting arms rotatably connected to trunnions affixed to the outside of the wall of the ladle and a beam above the ladle equipped with a hook. The cover may be equipped with a filling basin. In another preferred form, therefore, the present invention may provide a tiltable ladle having a cover and a suspension frame, the suspension frame comprising two lifting arms rotatably connected to trunnions affixed to the outside of the wall of the ladle and a horizontal beam above the ladle equipped with a hook, and in which the top of the ladle and the ladle cover are formed as segments of a cylinder, the focal axis of these cylinder segments being placed at one side of, above, at or below the pivot axis of the ladle, the cover being affixed to the suspension frame in such a way that the cover closes the ladle when the ladle and the suspension arms are in a vertical position. The invention may be carried into practice in various ways and two embodiments will now be described by way of example with reference to the accompanying drawings in which:- Figure 1 is a side elevation of ladle and a cover according to a first aspect of the present invention; Figure 2 is a cross-section taken along line I-I in Figure 1; Figure 3 shows the ladle of Figure 1 in a tilted position; Figure 4 shows the ladle of Figure 1 in a vertical position with the suspension frame and cover in a tilted position; Figure 5 is a side elevation of a ladle and a cover according to a second aspect of the present invention; and Figure 6 shows the ladle of Figure 5 in tilted position. The ladle in Figures 1 to 4 is equipped with a suspension frame comprising two ladle suspension arms 5, 6 rotatably connected to trunnions 7, 8 fixed to the outside of the ladle 1, and a horizontal beam 9 above the ladle 1. The horizontal beam 9 has a hook 10. A cover 11 is fixed to the suspension frame either by a first set of pins 12, 13, or alternatively by a second set of pins 14, 15, or both. The top of the ladle 1 and the cover 11 are formed as segments of a cylinder, the common axis of these cylinder segments being the pivot axis of the ladle. As can be seen from Figure 1, the cover 11 is arranged in such a way that there is a small gap between the top of the ladle 1 and the cover 11. Due to the suspension of the cover 11 and the shape of the cover 11 and the top of ladle 1, the ladle 1 can be freely tilted as shown on Figure 3. In addition, the suspension frame and thereby the cover 11 can be lowered so that the cover 11 will be automatically moved away from the ladle 1 when the ladle 1 is resting on a floor or the like as shown in Figure 4. In this way, molten metal and additives can be charged into the ladle 1. Figures 5 and 6 show another embodiment of ladle 30 having a suspension frame comprising two ladle suspension arms 31, 32 rotatably connected to trunnions 33, fixed to the outside of the ladle 30, and a horizontal beam 34 above the ladle 30. A ladle cover 35 is affixed to the suspension frame in the same way as described above in connection with Figures 1 to 4. The top of the ladle 30 and the cover 35 are formed as segments of cylinders, however, the focal axis 36 of these cylinder segments is spaced from the pivot axis of the ladle 30, this pivot axis being the axis connecting the fixing points for the trunnions 33. As shown in Figure 5 and 6 the common focal axis 36 of the cylinder segments is situated to one side of the pivot axis of the ladle 30. When the ladle suspension arms 31, 32 and the ladle 30 are in vertical position, the cover 35 closes the ladle. The ladle 30 can now only be rotated in the direction shown by the arrow 37 in Figures 5 and 6. As soon as the ladle 30 starts to tilt, the top of the ladle 30 will start to move away from the cover 35 and allow free tilting of the ladle. When the ladle 30 is tilted back to its vertical position, the cover 35 will again close the ladle 30. The cover of such a ladle may be merely a cover or it may be a cover equipped with a filling basin, commonly referred to as a "tundish".

Claims: A tiltable ladle assembly comprising a ladle (1), a cover (11) and a suspension frame, the ladle (1) being pivotally supported by the suspension frame, characterised in that the top of the ladle (1) and the ladle cover (11) are formed as segments of a cylinder, having a common axis, and the cover (11) is affixed to the suspension frame. An assembly as claimed in Claim 1, characterised in that the common axis of the cylindrical segments coincides with the pivotal axis of the ladle (1). An assembly as claimed in Claim 2, characterised in that the cover (11) is affixed to the suspension frame in such a way that there is a gap between the cover (11) and the ladle (1). An assembly as claimed in Claim 1, characterised in that the common axis of these cylindrical segments is spaced at one side of, above, or below the pivot axis of the ladle. An assembly as claimed in Claim 1 or Claim 4, characterised in that the cover (11) is affixed to the suspension frame in such a way that the cover (11) closes the ladle (1) when the ladle (1) and the suspension arms are in a vertical position. An assembly as claimed in any preceding claim, characterised in that the suspension frame includes two lifting arms (5, 6) rotatably connected to trunnions (7, 8) affixed to the outside of the wall of the ladle (1) and a beam (9) above the ladle (1) equipped with a hook (10). An assembly as claimed in any preceding claim, characterised in that the cover (11) is equipped with a filling basin.

Inventors: WHITE, DOUGLAS S.
Applicants: ELKEM A/S
Application year: 1989
Main classification: C21C7
IPC codes: B22D41, C21C1