Multi-Objective and Multi-Rate Control of the Grinding and Classification Circuit with Electromagnetic Mill

Abstract

The paper presents an innovative construction and installation of dry grinding in electromagnetic mill that provides a significant reduction of energy consumption when compared to traditional mills. The installation constitutes complex multi-objective plant. To gain control over all the objectives, hierarchical structure of control system was developed where different time-horizons involve multi-rate scheme of steering. The paper presents solutions for the direct regulation, supervisory control, and optimization level. The electromagnetic mill installation constitutes a unique setup that causes open loop instability and implies the application of novel control schemes at all of the levels. The paper presents these solutions and illustrates them with the results of experiments carried out on the electromagnetic mill installations.

Comparison of Wet and Dry Grinding in Electromagnetic Mill

“…Such a system for dry grinding process was developed [14] and patented [15] by the consortium of Polish universities and companies: Silesian University of Technology, AGH University of Science and Technology, ELTRAF Company (EMM producer, Lubliniec, Poland) and AMEplus Company (integrator of automation systems, Gliwice, Poland). Modelling of the air transport paths was carefully studied [16][17][18], classification capabilities were examined [19,20], and control problems were discussed [21][22][23]. Section 2.2 describes the idea of the entire system and describes differences between wet and dry grinding circuits.…”

Measurement-Based Modelling of Material Moisture and Particle Classification for Control of Copper Ore Dry Grinding Process

“…An innovative complete grinding system employing the electromagnetic mill is a dry grinding circuit with recycle of too coarse material, underpressure transport system and layered automatic control system, as described in [ 16 , 18 ] and shown in Figure 1 .…”

“…The whole installation is equipped with numerous direct and indirect sensors measuring flows, temperatures, pressures, air humidities, material moistures, consumed electrical power, fill level of the working chamber, particle size distribution and other quantities (see e.g., [ 16 , 18 ]). These measurements are used by a hierarchical control system built of programmable logic controllers (PLCs) and the Supervisory Control And Data Acquisition (SCADA) system [ 16 , 18 ]. The layered structure and complexity of the control system creates a need for various models on which the control algorithms may rely.…”

Combining Segmentation and Edge Detection for Efficient Ore Grain Detection in an Electromagnetic Mill Classification System

“…Grinding is invaluable in carbon steel microstructures [1], metal ore milling [2], cement production [3], minerals [4], powder technology for the food industry [5], and the pharmaceutical industry [6], among others. Based on final particle size, time consumption, parameters of the grinding process, grinding media, assumed particle size, and type of material used, we identify various types of mills that have described in recent literature—the ball [7], vertical roller [8], electromagnetic [9,10], pin mill [11], Buhrstone [12], and others.…”