Productivity Model for a Pickling Line

IPACT recently completed a productivity model for a continuous pickling line at a major steel producer.  The intent of the model was to significantly improve the tons per hour through the line by selecting the optimum line conditions and to decide what additional line automation might be included to aid the operator.  The model was required to accurately represent the entire line operation as it existed and then to show the increase in productivity after modification were made.  The increased productivity predicted by the model would be used to justify any expenditure for improvements.

The pickling line had originally been designed to operate as a continuous process, using entry and delivery loop cars to store strip, such that the steel passing through the descaling hydrochloric acid bath would not stop.  In reality, this concept had never been achieved, and the pickling portion of the line was always waiting on either the entry or delivery sections of the process.

To study the entire line and understand how the original line design, the operator’s control methods, incoming coil size, and possible automation improvements might be used to increase the line productivity, IPACT was contracted to write a model.  The model was quite extensive and complex as it had to account for all aspects of line operation, including the simultaneous but varying speed capabilities of the entry center and delivery sections and the overall loop car storage capacity.  The model findings were significant including:

• Improper setting of the loop car limit switches

• Additional delivery automation was required

• Operator had too much control of the line speeds

• Coil length had a significant impact on loop car operating point

• Optimizing coil length could optimize production (this does not mean making the largest coil possible)

• Some equipment should be relocated

The results of the process simulation were used to provide the justification for the cost of the improvements.

Integrated Process Automation & Control Technologies