Optimizing the control system of cement milling: process modeling and controller tuning based on loop shaping procedures and process simulations

Abstract

-Based on a dynamical model of the grinding process in closed circuit mills, efficient efforts have been made to optimize PID controllers of cement milling. The process simulation is combined with an autoregressive model of the errors between the actual process values and the computed ones. Long term industrial data have been used to determine the model parameters. The data include grinding of various cement types. The M -Constrained Integral Gain Optimization (MIGO) loop shaping method is utilized to determine PID sets satisfying a certain robustness constraint. The maximum sensitivity is considered as such a criterion. Both dynamical parameters and PID sets constitute the inputs of a detailed simulator which involves all the main process characteristics. The simulation is applied over all the PID sets aiming to find the parameter region that provides the minimum integral of absolute error, which functions as a performance criterion. For each cement type a PID set is selected and put in operation in a closed circuit cement mill. The performance of the regulation is evaluated after a sufficient time period, concluding that the developed design combining criteria of both robustness and performance leads to PID controllers of high efficiency.

Determination of granulometrical composition of the clinker by grinding in a ball mill to determine the specific consumption of additional energy

“…More energy efficient grinding technologies, applied in the grinding of cement, are described comparatively in the paper [6], from the point of view of operating principles, grinding efficiency, specific energy consumption, the production capacity and the quality of the cement obtained. Other papers addressing the theme of milling process with balls dedicated to grinding cement, including its control are [7][8][9][10][11] The present paper presents the results regarding the grinding behaviour of two batches of material (clinker) in a ball mill with its own two-step grinding process: the first one with a ball load, the second with a load of cylindrical metal bodies.…”

Predictive Control of a Closed Grinding Circuit System in Cement Industry

“…Many contributions have been made in the control of grinding circuits. For instance, reference [3] proposes a dynamical model of the grinding process to tune the PID controllers involved in the cement milling by the loop shaping method.…”

Dynamic Analysis of the Temperature and the Concentration Profiles of an Industrial Rotary Kiln Used in Clinker Production

“…Some of the challenges facing the cement industries are the high energy demand of production, the continuous increase in fuel prices, process complexity and environmental impact (Atmaca and Yumruta 2014, Tsamatsoulis 2014, Kaddatz et al 2013, Gartner and Macphee 2011, Schneider et al 2011, Mujumdara et al 2007). To address these challenges, there is great interest in optimising the cement production process (Copertaro et al 2015, Utlu et al 2006.…”