Influence of the natural gas composition and flue gas recirculation in a reverberatory furnace for nickel alloys

Abstract

A reverberatory furnace for nickel refining is an open flame furnace that comes from a burner, which uses natural gas as fuel; and which working temperatures vary from 1450°C to 1550°C. In reverberatory furnaces there is a waste of heat generated by the burners. If we in time use an adequate recirculation of the combustion gases from the flame we could increase the fraction of heat transferred to the molten metal, in our case, nickel alloys. In this work, we developed a CDF modeling for this type of furnaces to optimize the dynamics of the exhaust gases, to contribute to a more efficient smelting process, focusing on the fact that the efficiency depends on the composition of natural gas. In our study we used 3 different compositions of natural gas, focusing on the percentages of methane with 95.89% Russian natural gas, with 89.67% Spanish and with 89% Bolivian natural gas. This modeling allows us to work with fluid dynamics, combustion and heat transfer, using the Finite Volume Method. Radiation is a very important process to take into account and is adapted to calculate heat transfer. The modeling has been using the ANSYS CFD 19R3 program. The results show the influence of the composition of natural gas on heat transfer in reverberatory furnaces fed with natural gas.