Long in the Tooth!

Long in the Tooth!

Long in the Tooth

One of IPACT’s long term clients contacted us regarding the possibility of migrating their Stove Control System.  The stove control
automation was still functioning but becoming dated.  The cost of spare parts and support for this antique system was becoming more difficult and very expensive to acquire.  IPACT reviewed the system and determined that the many of the algorithms used in existing system didn’t take advantage of the latest control theory about Stove Control management.

IPACT put together a budgetary proposal including replacing the proprietary DCS controls with Control Logix, updating the control logic to modern control theory, and replacing the operator interfaces with modern HMI’s.

The expected benefits include:

  • A PLC based solution that is fully documented, including diagnostic SFC’s, and supportable by existing plant personnel.
  • A reduction of errant stove cycle changes, reducing required maintenance.
  • A reduction of the fluctuations in blast furnace operating parameters providing a more uniform product quality.
  • A modern, open information system easily enabling analysis to drive process improvements.
  • A tunable stove control model optimizing fuel and cycle times during all operating modes.
  • Individualized stove controls tuned and optimized to provide the best performance for each stove.
  • A more optimized firing practice during the gas cycle.
  • A reduction in energy usage.
  • Improved stove performance when the blast furnace is throttled due to reduced downstream demand (e.g., blowing at 50% wind because of a BOF outage).
  • Maximized stove life.
  • Stove Control System can provide condition based monitoring information to the CMMS, resulting in reduced maintenance and fewer emergency repairs.
  • Routine engineering maintenance of I/O scaling, alarm limits, etc. can be done from the HMI and does not require programming in PLC or System Platform.
  • Enhanced combustion control model – simple, flexible, adapts to handle common instrumentation issues.
  • Combustion control programmed using A-B function blocks for easy understanding.
  • An improved ability to correlate stove operation to furnace operation.
  • An improved ability to report on stove cycles for utility usage.


The system was staged in IPACT’s headquarters for testing with an advanced modeling and simulation.  The client is looking forward to measuring the long term benefits of the solution!  Payback is expected to be less than a year.