The development of energy-efficient process for the high-temperature processing of bulk carbon materials in electric furnaces
The physical and mathematical models of the dynamics of the dense motion of a granular medium and the thermoelectric state of a single-phase mine electric furnace during high-temperature heat treatment of carbon material are formulated, on the basis of which the corresponding discrete and continuum numerical models of the physical fields of the electric calciner are developed taking into account the dense motion of the granular medium and chemical interaction. Verification of numerical models showed that the error in numerical solutions has the following meanings: for total electrical resistance and current strength does not exceed 14%; for temperature values in the absence of local overheating no more than 17%. The temperature dependences of the electrical resistivity and thermal conductivity coefficient of anthracite and petroleum coke processed in electric calciners were experimentally determined, and their comparison with published data was performed. Experimental campaigns for the high-temperature treatment of anthracite and petroleum coke in alternating current electric calculators of various designs were carried out and a detailed analysis of the obtained experimental data was performed. A system of dimensionless technological and geometric parameters for the operation of electric calcinators of various designs and purposes has been developed, which is a powerful tool for obtaining resource-efficient technical solutions for upgrading the technology of high-temperature processing of carbon-containing fillers. Resource-energy-efficient regulations have been developed for the launch and operation of electric calcinators for calcining anthracite and petroleum coke, ensuring high quality of the final product. Based on a comparative analysis of the energy efficiency of DC and AC electric calciners, it was found that direct current electric furnaces are characterized by significantly lower specific energy costs compared to AC furnaces. The possibility of obtaining European-level carburetors of quality in electric calciners of JSC "Ukrgrafit" is proved.