Electricity and Control July 2021

MEASUREMENT + INSTRUMENTATION

Optimising comminution processes

The environment inside a stone crusher is pretty rough, characterised largely by loud noise, dust and intense vibration. But there’s also a completely different side to such machines.With innovative measurement technology and algorithms, the stone crusher has become a highly sophisticated piece of equipment; individual process steps are optimised in real time, significantly reducing energy consumption. Sensors fromVEGA help make this possible.

E very particle, every grain and every stone is consid- ered important at Ma-estro. The Italian company has been optimising comminution processes and crush- ing machines for over 15 years. It helps that the founder of the company has his own quarry and therefore has known for a long time which measures help and which are use- less in practice. Today, the company offers automation and optimisation systems for all production processes found in quarries, mines and recycling facilities. Crushing machines require a lot of energy to produce the finished product. In addition to the actual comminution, processes such as pre-washing, cleaning and sorting must be taken into account. Solutions from Ma-estro ensure that the energy consumption per tonne of product, one of the main production cost factors, can be significantly reduced. The key to this lies in intelligent automation of the entire production chain and real-timedatamanagement. Ma‑estro’s systems virtually dismantle the entire crushing process, from the quarry to the end product, and assess many individual parameters in the various processes from different angles. Parameters such as production rate, energy consumption, machine efficiency, plant downtime, maintenance figures, material transport, and fuel consumption are considered. In effect, each kilowatt is examined individually. On average, 15% of the total energy consumption can be saved in this

way. These efforts are the result of considerable investment in research and development every year, including, for example, in the design of new sensors and the development of new software algorithms. A good end product It is not only energy costs that are in focus in optimisation. The real challenge for the operator – of a quarry, for exam- ple – is to deliver an end product with uniform quality. He also has to deal with the fierce competition among compa- nies that produce basic, standard products. Quality and reproducibility, in turn, depend to a large extent on the load to which the crushing machines are sub- jected. The harder the material, the greater the stress on crushers and mills. Wet material can also become a prob- lem for conveyors, hydrocyclones and screens. In addition, the properties of the raw materials, such as mass, density or hardness, can change. This places constantly fluctuat- ing demands on plant components such as crushers and screens. Manual intervention in the process is usually difficult. The aim of continuous monitoring of the individual process steps is therefore to reduce the load on the respective ma- chine components – contingent upon the current situation in the crusher. Ma-estro’s system automatically controls the entire process by interconnecting all the machines in the system. The sensors installed in the critical areas make it possible to adjust the load in the individual parts of the sys- tem constantly. For example, charging is controlled, materi- al flow is adjusted or clogging scenarios are predicted and avoided. This protects the equipment, saves energy and leads to higher product quality. Reliable level measurement For Ma-estro, sensor technology plays a major role, quite in keeping with the motto: ‘What can’t be measured, can’t be optimised either.’ For about a year already, measurement technology from VEGA has been used in the monitoring and optimisation of the crushing machines. A total of 50 in- struments are being used for this, including VEGASON 61, 62, 63, VEGAPULS 69 and VEGABAR 82. Most of the de- ployed sensors are level sensors. VEGA radar technology

The main objective of automated control in stone crushing systems is to identify and resolve the discrepancies caused by raw material variability.

14 Electricity + Control JULY 2021