Efficiency evaluation of a new electric modular descending furnace according to the performance factor for energy blocks

The present work is focused at the study and experimental confirmation of the possibility for increasing the efficiency of an electric modular descending furnace in terms of reducing the specific energy consumption of roasting vermiculite concentrates by obtaining the most rational structural furnace design. Research methods were based on a theoretical analysis of the working process energy characteristics for the furnace unit, such as performance factor and specific energy consumption, the laws of thermal radiation physics and thermal engineering, as well as on the analysis of experimental data obtained during testing of the experimental furnace model under laboratory conditions at a temperature of 730-780ºС and an annealing time of 2.48-3.06 s. Due to changes in the structure of the six-module furnace, the specific vermiculite roasting energy consumption was reduced to 188.9 and 197.0 mJ/m3 in accordance to calculated and experimental data, respectively. As compared to the minimum value for a standard similar furnace, the decrease in the specific energy consumption for the modernised furnace amounted to 17.9%. The effect of reducing energy consumption was shown to be due to the structural transformation of the furnace unit by transferring the lower module with a lowest performance factor and installing it in parallel with the upper module, leading to a significant increase in the overall efficiency of the furnace. Additional efficiencies were obtained by applying suspended heating systems to the furnace under consideration. According to calculations and experimental studies, due to the furnace unit structural transformation and the use of more energy-efficient suspended heating systems in the furnace energy blocks, the expected combined effect of reducing the specific energy consumption in roasting vermiculite concentrates averaged up to 147.3 mJ/m3 for various types and size groups of furnaces.

electric modular descending furnace, structural furnace design, six-module furnace, suspended heating system, specific energy consumption of roasting