Energy efficient rolling mills

ABB researchers have come up with a unique software tool, the ADM (Adaptive Dimension Models) toolbox to calculate the best possible operating settings for stable, accurate and energy-efficient production in rolling mills.

Every day, rolling mill operators battle with process instabilities that interfere with production. Many operators pride themselves on being able to reset system parameters intuitively, but this takes time and delays are expensive in terms of materials, energy and lost productivity. To help operators minimize such interruptions and smooth the transition between different rolling processes, ABB has developed a new software application for advanced rolling process optimization: the ADM toolbox.

When rolling mills switch from processing one material or finish to another, they must resume production as quickly as possible to avoid wasting raw materials and squandering energy on idling machines. To ensure that the transition is achieved as efficiently as possible, ABB researchers have come up with a unique software tool, the ADM (Adaptive Dimension Models) toolbox. This calculation module uses state-of-the-art simulation methods to guide the operator through the best possible parameter settings for stable, accurate rolling and it works in conjunction with ABB’s Rolling Mill Control (RMC™) and Interstand Dimension Control (IDC™) systems.

Optimization, simulation and calibration

The ADM tool improves equipment availability and yield by simulating the optimal rolling conditions and delivering the appropriate parameter settings to the operator via an easy-to-use screen interface. The settings are calculated in less than a minute and results can be communicated directly to the RMC module that controls mill operations. The ADM unit can also respond to deviations in the rolling process detected by the IDC unit and revise recommended settings in a matter of minutes.

The IDC concept was developed for rod and bar mills to allow machines to run closer to their theoretical limits, as well as to improve product quality, yield, and availability. It is an early indicator of abnormal mill conditions, measuring the dimensions and position of the bar. This allows operators to roll closer to specified tolerances, reducing the amount of material needed.

The key component is the U-gauge™ for bar dimensional measurements and which provides the ADM tool with on-line readings for ADM model accuracy improvements.

Minimization of energy consumption

The ADM software also considers energy efficiency when calculating optimum parameter settings . Pinpointing the optimal speed and other process parameters for energy minimization relies on complex mathematics and physics, but ADM can calculate the recommended settings in a matter of seconds. Until now, such an optimization approach had been considered beyond reach.

In examples using real mill set-up data, improved rolling schedules calculated with the ADM tool are estimated to save as much as 10 percent of energy costs. In such an energy-intensive industry, the financial benefits of such a saving are considerable.

Towards on-line optimization

In theory, optimization time could be reduced further, to within 1 or 2 seconds, using the latest developments in digital optimization. ABB researchers are currently working on a fully automatic on-line optimization tool, which would remove the need for the use of trial billets and thereby save even more energy.

ADM – a new standard in hot rolling

The ADM tool is set to become a new standard in rolling mill automation. Its ease-of-use, robustness, and accuracy make it a valuable addition to ABB’s of rolling mill control tools. It also helps to demystify the subtle art of product change and fine-tuning process lines in mills.

For more about ABB’s energy-efficient technologies, read the ABB Review on energy efficiency.