IMPROVEMENT OF THE ELECTRIC DRIVE OF TWIN-SHAFT MIXERS

Abstract

Relevance. A priority for modern industrial power engineering is the systemic integration of resource-saving innovative technologies while improving productivity. In this context, the design of highly energy-efficient electromechanical systems and the digital automation of their control algorithms remains a key element of global technological transformation. Twin-shaft mixers play a key role in complex process cycles in the chemical, metallurgical, and construction industries, particularly in the homogenization of refractory and acid-resistant components. However, traditional electric drive systems with single-speed asynchronous motors in use in practice have a high inertia coefficient, leading to irreversible energy dissipation during transient conditions (startup and braking). This, in turn, reduces the overall system efficiency and causes an exponential increase in operating costs. Modernizing existing low-efficiency and inertial drives with intelligently controlled contactless modules is considered the optimal solution for minimizing energy consumption, extending the service life of devices, and ensuring process stability. Target. Development and research of a two-speed asynchronous motor (DM) with a PPO for the electric drive of a two-shaft mixer providing a step start, precise stop and increased efficiency of the technological process. The following methods were applied in the work: electromagnetic calculation with the selection of optimal winding parameters for the analysis of DD with PPO at a pole pair ratio of 2:4; computer modeling in the ANSYS Maxwell software environment for magnetic field analysis; development of a contactless starting circuit for two-speed asynchronous motors; experimental studies of a prototype AIR180M8/4 motor with the acquisition of operating, mechanical and starting characteristics under production conditions. A new pole-switching winding circuit was developed, and the AIR180M8/4 two-speed motor was designed based on it. The motor produces 18.5 kW at 1500 rpm (p=2) with 90% efficiency and 13.9 kW at 750 rpm (p=4) with 85% efficiency. The implementation of a contactless commutation system ensures long-term, safe, quiet, and reliable operation of the electric drive. Industrial tests at the facilities of Almalyk Mining and Metallurgical Combine JSC showed that the motor's integration into the VL-400-VRU mixer drive reduced the rotation cycle by 420 seconds and increased the daily mix capacity by 580 kg