Optimization of Post Combustion in Steelmaking (TRP 9925)

Fruehan, Richard J. ; Matway, R. J.

American Iron and Steel Institute

关键词: Heat Transfer;    Combustion;    Flow Rate;    Electric Arcs;    Oxygen;   

DOI  :  10.2172/840945
RP-ID  :  NONE
RP-ID  :  FC36-97ID13554
RP-ID  :  840945

美国|英语

来源: UNT Digital Library

【 摘 要 】

In the electric arc furnace (EAF), and the basic oxygen furnace (BOF) for producing steel, the major off gas is carbon monoxide (CO). If the CO can be combusted to CO{sub 2}, and the energy transferred to the metal, this reaction will reduce the energy consumed in the EAF and allow for more scrap melting in the BOF which would significantly lower the energy required to produce steel. This reaction is referred to as post combustion. In order to optimize the post combustion process, computational fluid dynamic models (CFD) of the two steelmaking processes were developed. Before the models could be fully developed information on reactions affecting post combustion had to be obtained. The role of the reaction of CO{sub 2} with scrap (iron) was measured at the temperatures relevant to post combustion in laboratory experiments. The experiments were done to separate the effects of gas phase mass transfer, chemical kinetics, and solid state mass transfer through the iron oxide formed by the reaction. The first CFD model was for the EAF using the FIDAP-CFD{trademark} code. Whereas this model gave some useful results it was incomplete due to problems with the FIDAP program. In the second EAF model, the CFX{trademark} code was used and was much more successful. The full 3-D model included all forms of heat transfer and the back reactions of CO{sub 2} with the metal and scrap. The model for the EAF was a full 3-D model and consisted of a primary oxygen lance with side wall injectors for post combustion. The model could predict the degree of post combustion and heat transfer. The BOF model was a slice of the BOF for which there was symmetry. The model could predict post combustion, heat transfer, temperature profiles and the effect of operating variables such as oxygen flow rates and distribution. The present research developed several new models such as limited combustion and depostcombustion. These were all documented by MSA Pass as a sub-contract. Instruction manuals were developed so the models could be used by industry. The work indicates considerable energy can be generated and usefully used in the BOF and EAF. The processes can be optimized for specific cases using the models developed.