Background. Powder grinding in jet mills allows obtaining pure powders for the chemical and pharmaceutical industries. To meet the required particle size distribution of the finished powder, it is necessary to operate the mill in a closed circuit with a classifier to separate the produced fractions, preventing their overgrinding. Thus, the development of adequate mathematical models and diagnostic methods of closed-loop jet grinding, which enable the formulation and solution of design and diagnostic problems for such systems is a pressing scientific and practical challenge.
Materials and methods. To model closed grinding cycles, formulate and solve inverse diagnostic problems, a matrix methodology to describe grinding, classifying, and closed grinding cycles has been used. The grinding model has been identified based on the results of specially conducted experimental studies.
Results. A mathematical model of a closed-loop jet milling system with an arbitrary structure of connections between elements has been developed. A matrix model of jet milling has been identified using the obtained experimental data. Within the framework of the presented model, the authors have proposed an approach to define and solve problems in the diagnostics and design of jet milling systems for efficient production of powders with specified characteristics.
Conclusions. The obtained results allow us to propose an approach to the development and implementation of new optimal jet grinding technologies to obtain highly pure products and diagnose the state of closed grinding cycles.