| OCR Text |
Show available for mini-mill applications. High purity oxygen is not required for the applications and concepts under consideration. Approach The technical approach has been designed to address and quantify the following key issues: Which temperature zones can effectively use OEA or O2, and what is the impact on refractory temperature? Where are the preferred furnace locations for injecting reburn fuel and overfire air, and are there potential process impacts? Are there secondary emissions or potential product quality issues caused by O2 enrichment and/or low temperature substoichiometric operation? What are the costs of implementation (O2 purchases and refractory service) and revenues (production increases and fuel reduction) which can be expected? How much NOx and furnace gas temperature changes can be expected? What are the critical design issues to be addressed in subsequent phases? The work is being conducted in three phases: Phase I, Research Development Definition (Study) Phase II, Design and Development Phase III, Field Demonstration This paper reports on the status of the Phase I Study. Activities include a) an evaluation of U S A furnace demographics which led to the development of a model furnace specification, b) computational modelling of the model furnace to select and quantify heat transfer and performance improvements, and c) conceptual design to establish capital and operating costs and benefits. The American Iron and Steel Institute is supporting this activity by providing peer review through their Energy and Environmental Committee. Air Products has developed a computational fluid dynamic (CFD) model to support the analysis of oxygen enhancing heat zone combustion to preferentially improve heat transfer to the steel. The C F D modelling results (flow field structure, temperatures, and species composition) are used as boundary conditions (see Figure 1) for three other computational models: • computational (jets in cross flow) and physical flow model to evaluate the effectiveness of mixing the reburn fuel into the post heat zone flue gases, and overfire air sufficiently downstream to accommodate the mixing and chemistry of the reburn zone one dimensional (multi stream tube) chemical kinetic model for NO reduction and C O oxidation control |
