A digital approach to optimize pelletizing plant operation via advanced automation and process modelling
5.1 Industry 4.0 within IronmakingSebastian Lang1
1 Metso Outotec
Text
Operation of straight grate iron ore pelletizing plants is demanding in many ways, so from an operational perspective, most challenges relate to issues in either process stability and control or in achieving the desired process result.
On one hand, issues with process stability often lead to decreased performance of the process and sometimes even threaten equipment lifetime. Due to their interconnected nature long lasting process dynamics and nonlinear system behavior, travelling grate induration plants pose a challenging problem to traditional controllers. This often leads to process instabilities and hence inefficiencies in operation. Solving these stability issues is important not only in their own right, but also since they are an enabler for improving operating points of the process to increase process efficiency, throughput and product quality.
On the other hand, achieving reliable process results under varying boundary conditions is frequently a challenge in everyday plant operation. Quantitative and reliable information of important influencing factors are often not available, making in-time operating decisions difficult. Additionally, product quality results are usually only available with low frequency and in retrospective.
In this paper, a strategy for meeting these challenges in everyday production with a digital system is described and exemplified by means of the Metso Outotec Optimus software. Such systems are usually based on a higher automation core to tackle process stability issues by exploiting knowledge about the short-term behavior of the indurating process. Furthermore, advanced knowledge about the long-term behavior of the process is infused into such systems, typically by means of process models. This allows to make unknown information available and to determine optimum plant operating points beyond pure stabilization. Such a combination of approaches enables to continuously increase process stability and performance.
