Influence of Auxiliary Fuel Injection to Tuyeres on Flame Temperature and Flooding Limits in the FINEX® Process: A Theoretical Investigation

Abstract

The FINEX® melter gasifier, in contrast to the blast furnace, uses oxygen instead of air for the blast, and the packed bed consists of coal char but not of coke. In this paper, the theoretical raceway flame temperature for FINEX® conditions has been calculated for different injection rates of auxiliary fuels and steam. A regression equation has been derived from these results. Moreover, a flooding limit has been taken into account when auxiliary fuels were injected in order to understand the practical operational troubles such as peaks of reducing gas flow and temperature. The theoretical investigations show, that the available heat level in the raceway has been sufficient enough to inject the auxiliary fuels, such as pulverized coal (PC) and natural gas (NG) at the same rate and even higher than regarding the blast furnace. The permeability of the FINEX® char bed is lower in comparison to the coke bed in the blast furnace. High injection rates of auxiliary fuels require enhanced char stability and bed voidage.