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Show CHARACTERIZATION OF NATURAL GAS-FIRED AND ALTERNATIVE STEEL REHEAT TECHNOLOGIES Gayle Schlea Koch, James H. Williams Hagler, Bailly & Company Washington, D.C., USA ABSTRACT A current market profile is developed for the following natural gas-fired and alternative steel reheat technologies: walking beam, pusher, batch, and induction. The entire natural gas reheat market currently is approximately 135 x 1012 Btu per year out of a total potential reheat market of 187 x 1012 Btu per year. Future steel industry structural and technological trends are examined for potential impacts on the natural gas reheat market. The most important impacts will result from future implementation of hot charging, direct rolling, and thin strip casting. R&D opportunities for improving the competitiveness of gas-fired reheat technologies are discussed, including research in combustion fundamentals and furnace des ign, deve lopment of improved sensors and controls, and distribution of information to industry users. ALTHOUGH NATURAL GAS has been the industrial sector's preferred energy form over most of the past two decades, the relative portion of gas consumption in recent years has shown substantial declines, and electricity use has shown a persistent and relentless growth in market share, even though electricity has been -- and still is -- the most expensive energy form. The reasons for this trend and the future outlook for many large industrial gas markets have not been systematically analyzed nor well documented. Many technical, economic, and market factors underlie the broad structural changes now occurring in the U.S. industrial sector. Future levels of industrial gas consumption and the requirements to be placed on new gas technologies will depend, in part, on how further industrial and technological restructuring evolves. Accordingly, the industrial se~t~r p~esents ~he challenges of understanding, antlclpatln~, an~ Influencing the role of new gas technologles ln an ever-changing manufacturing environment. As a step toward identifying specific technology developments needed to maintain the effectiveness of gas technologies, the Gas Research Insti-tute is sponsoring a series of studies to develop a quantitative estimate of the current and future competitive position of natural gas compared with other energy sources in selected industrial process heat applications. Hagler, Bailly & Company was engaged to develop information on the technologies, processes, and market environment affecting the future of natural gas use for steel reheating, as well as other applications. Steel reheat is a major industrial gas market and represents the largest single application of process heat. 295 STEEL REHEAT FURNACES Semi-finished bloom, slab, and billet steel products must usually be reheated prior to rolling into finished products. Steel reheat furnaces raise the temperatures of these semi-finished products, as uniformly as possible, to levels necessary for hot rolling. The temperatures are a function of the steel composition: Steel type High carbon Medium carbon Low carbon (with no alloying elements) Rolli.ng temperature (OF) 1,950-2,050 2,000-2,100 up to 2,350 A standard steel reheat furnace consists of the following components: • A heating chamber that contains the material (charge) and retains heat • A hearth or support in the furnace for carrying the charge • Facilities to control and maintain temperature • A distribution system for heating and waste gas removal • A materials handling system to introduce, move, and remove work from the furnace. |