Feature of Increase in Energy Efficiency of High-Temperature Industrial Furnaces With Resistive Heating

Abstract

For the sintering of ceramic products, high-temperature electric furnaces are used, which work both in a protective environment and in air. In some technological processes, for example, for the production of ceramic carriers for afterburning car exhaust gases based on SiC and Al2O3, only air furnaces are used. Silicon carbide (SiC – silicate) heaters and molybdenum disilicide (MoSi2) are used as resistive heaters in such furnaces. Due to the relatively small resource of their work, it is energetically beneficial to use the residual heat when cooling the furnace. At the same time, there is a significant saving of electricity for heating. The residual heat is largely determined by the thermal insulation of the lining and the correct distribution of the heat balance of the furnace. The speed of temperature rise affects the thermal balance of the furnace in general, and even the speed of cooling of the furnace, which creates additional energy saving opportunities, which reduces the cost of ceramic products. The article examines the technological processes of sintering ceramic products in high-temperature electric furnaces. A calculation algorithm was selected for performing comparative assessments of energy intensity and possible implementation, which can be used in the analysis of specific situations regarding different types of ceramic parts, the sintering temperature of which exceeds 1400 °C. A factography of the dependences of the power distributed over the floor area on the floor area and the specific power on the internal volume for a range of models of Mobilotherm furnaces designed for firing ceramics with the maximum operating temperature was obtained. It was found that the additional reduction in energy consumption during sintering in electric furnaces for the production of one product and the increase in production productivity are associated with the balancing of the thermal balance of the furnace, the reduction of heat losses and the use of furnace designs in which residual heat can be used. The conducted studies make it possible to assume that the developed methods of calculating the heat balance allow choosing the most optimal furnace heating modes, recommending the most heat-resistant and heat-insulating lining materials.