New Technique for Smoother, Safer Molten-Metal Handling

June 17, 2009
A lance-based slidegate design is a simple, effective, and affordable approach to improving casting and raising cast-metal quality.
Opening the casting channel is a three-step process: insert S.O.S., position the shroud tube, connect the oxygen lance.

Casting molten metal is always a dangerous process, and Reinguss GmbH engineers have sought to address that fact even as they approach a solution to one of its most vexing problems — slidegate blockages.

The German engineering firm specializes in process designs and equipment for optimizing casting, particularly for steelmaking operations. Its products include shroud-tube manipulators for casting platform automation, and equipment for tundish preparation, and furnaces and casting machines for foundries.

Slidegate blockages are common, especially during continuous casting. The new Slidegate Opening System (S.O.S.) clears blockages during continuous casting, and thereby eliminates the dangerous and time-consuming procedure of “burning out” the slidegate with an oxygen lance. Reinguss promises its new equipment and procedure will increase workplace safety and save production time, at the same time ensuring the high quality of the metal.

The core of the system is a simple mechanism that attaches as a shroud tube to collector nozzle of the ladle. If the slidegate is blocked, the shroud tube is removed from the nozzle and the S.O.S. is inserted inside the tilted shroud tube. The S.O.S. burns out blocked casting channels quickly, which the safety for workers and improves the qualit of the steel being cast. It can be used for either open or submerged casting, Reinguss indicates.

Flexible tension springs are used to keep the S.O.S. positioned properly. After the shroud tube is returned to the casting position on the slidegate nozzle, the operator links the oxygen lance to the funnel on the lower end of the outer tube, and opens the oxygen supply. Gas pressure drives the inner tube upward, including the enclosed starter unit. It ignites automatically and burns out the blockage using the lance-supplied oxygen until the melt is discharged.

The S.O.S. is designed to be inserted into the shroud tube, with flexible tension springs to keep it properly positioned.

At this point, because the shroud tube is already in position, liquid steel is not exposed to ambient air. For submerged casting processes, Reinguss supplies an adapter that allows oxygen burn-out and connection to the oxygen lance outside of the tundish.

Because the design is so simple, the S.O.S. is priced affordably. But, feasibility studies in Europe indicate annual savings in production time, and product quality savings estimated at more than $400,000 if the S.O.S. is used to un-block just 50 ladles.