CastView
monitor nozzle clogging

CastView Brochure in PDF Format

Nozzle Clogging
and
Caster Information System.

The build-up of inclusions within nozzle systems can cause quality defects and productivity reduction. This tenacious problem plagues the majority of aluminum killed steel casting operations. There are numerous factors that influence clogging and several solutions are available, but their application requires an effective quantitative tool to measure progress and inform operators. To satisfy this requirement, Nupro Corporation has developed CastView, the real time operator interface program that tracks castability, casting speed limit, and other important casting parameters.

Immediate Benefits:
- Visual representation of nozzle clogging in real time
- Display casting speed limit imposed by clogging
- Reduced mold turbulence and downgrades
- Real time feedback to caster and LMF operators
- Quantitative approach to clogging remedies and downgrades
- Accurate assessment of parameters effecting nozzle clogging
- Optimal calcium addition program
- Historical trending and recording of clogging and other parameters
- Many alarm and process integration features available

Advanced Technology
The interface is installed on an industrial computer and connected to the network to track process parameters. The proprietary software compares actual to theoretical casting rates and flow control positions. This comparison will produce a real time output of the percent and rate of nozzle clogging, the upper limit on casting speed, and the general trends associated with these and other parameters. The interface may be custom designed according to the specific needs of each installation. An example is shown at the right.

Corrective Measures
If nozzle clogging becomes severe during casting, the operator may use countermeasures such as rodding or gas purging to clear the nozzle. If these measures are ineffective, a casting speed change may be required. In either case, mold turbulence and unsteady casting conditions may cause surface defects, downgrades, and further nozzle clogging. The CastView system can help to avert this situation by consistent and reliable prediction of impending problems, leading the operator to preemptive action. The history of such events and their relation to process parameters can lead to effective practice changes to reduce oxide build-up in pouring systems.

Improve Process Control
The CastView interface can be used as a real time process control tool, for example in calcium addition to the tundish. The rate of change of nozzle clogging percentage can be tied to the calcium addition rate for optimum inclusion modification and castability.

The figure on the right shows the nozzle clogging history for three ladles of a steel grade that is prone to severe alumina clogging. Calcium treatment in the ladle was applied on the first and third ladles, but not on the second. Clogging was not eliminated, but was held somewhat under control in the calcium treated heats, but a high rate of clogging and a significant "nozzle flush" are evident in the second ladle. Using this information, the calcium program was reviewed and continuous improvement is underway.

CastView can also improve control of argon flow to various locations in the nozzle system. Back pressures and flowrates may be optimized by integration with the real time rate of change of nozzle clogging. Parameters indicative of cracked nozzles and argon bypass can be monitored and an alarm can be implemented to notify the operator. The location of clogging may also be inferred in many cases.

System Integration
CastView^TM is available as a stand alone system or as an option to the Slag Detector slag detection system. The flexibility and integration potential of CastView makes it a valuable process tool and an indispensable aid for practice development in the reduction of nozzle clogging. Example functions useful to caster operators:
- Steel weight in ladle and tundish
- Flowrate and pressure for each argon input
- Rate of change of nozzle clogging.
- Casting speed limitation due to clogging.
- Alarm excessive clogging.
- Alarm impending casting speed limitation.