we, machine incharges of casting floor, have damaged the cables of ladle-slag detectors as they hang down from ladles during rotation. manual errors have damaged them repeatedly, so these cables were not restored anymore.
the responsibility then fell on the machine-in-charges to detect and stop ladle slag from entering into tundish. manual and visual observation is bound to have errors, and in such cases accumulation of heavy ladle slag in tundish have a lot of adverse effects on casting.
tundish steels gets excessively oxidized, crust formation on top of tundish obstruct sample collection and manual temperature measurements can be a lot misleading.
automated monoblock stoppers may get jammed due to heavy slag around them leading to heavy torque and failure of actuators.
excessively oxidized steel can erode tundish slidegate plates or monoblock stopper tips leading to running of strands.
during such times it becomes an absolute necessity to drain the slag through the overflow spout into the emergency containers provided there is enough space for it.
pic below shows one such incident where slag is drained off tundish. it must be noted, steel should not be drained along with slag as this is a heavy loss.
from the pic one must be able to understand how slag (with glass formers like Silica and alumina) form a continuous thread while flowing down the spout WITHOUT BREAKING OR SPLITTING OFF as soon as flowing out.
the responsibility then fell on the machine-in-charges to detect and stop ladle slag from entering into tundish. manual and visual observation is bound to have errors, and in such cases accumulation of heavy ladle slag in tundish have a lot of adverse effects on casting.
tundish steels gets excessively oxidized, crust formation on top of tundish obstruct sample collection and manual temperature measurements can be a lot misleading.
automated monoblock stoppers may get jammed due to heavy slag around them leading to heavy torque and failure of actuators.
excessively oxidized steel can erode tundish slidegate plates or monoblock stopper tips leading to running of strands.
during such times it becomes an absolute necessity to drain the slag through the overflow spout into the emergency containers provided there is enough space for it.
pic below shows one such incident where slag is drained off tundish. it must be noted, steel should not be drained along with slag as this is a heavy loss.
from the pic one must be able to understand how slag (with glass formers like Silica and alumina) form a continuous thread while flowing down the spout WITHOUT BREAKING OR SPLITTING OFF as soon as flowing out.
this slag thread slowly draining off the spout explains a lot, about the high viscosity (around 10times that of liquid steel), that results from interlinking of CaO, silica, alumina and other network forming, slag making molecules that does not allow splitting or breaking off of streams (which normally happens when liquid steel flows.) one can easily identify what overflows is metal or slag with this simple idea in mind.
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