Cases

Financial sustainability with best practices.

Vale

Advanced Process Control - Indurating Furnace

Customer: VALE

Location: Vitoria-ES

Challenge: The goal of indurating furnaces is to produce pellets under specific characteristics in terms of chemical composition, size distribution, hardness, cold compression, reducibility, disintegration, aiming at maintaining quality objectives with a minimum standard deviation and also minimizing the consumption of fuel and electricity.

Solution: The system is designed for the optimum control of CVRD furnaces with the use of two independent systems which communicate with each other continuously. The first of these is the control module, which reflects the knowledge of operators and engineers and still uses advanced statistical tools and nebulous logic techniques. The second module processes the dynamic process model. The models used are equations of the firing and hardening process of the pellets associated with a gas balance model for the whole process. The dynamic model provides the following benefits and facilities:

  • On-line quantification of non-measurable variables that influence the quality of pellets through the process (Soft Sensor);
  • Early detection of changes in the variables that influence the quality of pellets;
  • On-line prediction of some pellet properties and their variations at all points of the furnace;
  • The predictions of the model are used in the rules to implement appropriate actions to maintain the quality of pellets when some disturbance occurs in the process;

Result: The implementation of the model-based optimization control system in the pelletizing furnace is a guaranteed way to maximize the economic performance of the industry, interrelating the localized objectives and aiming at the profitability of the enterprise as a whole.