프로파일 최적화 시뮬레이션 기반의 소결 공정 사이클로이드 형상 롤 장입슈트 모델링

Abstract

The steel production plant industry is required to turn over to global low-carbon systems, as it is known to contribute 14.3% of domestic greenhouse gas emissions in 2021 in Korea, about 80% of which are generated in the iron-making process. Reducing the coal consumption of the sintering process has become a significant challenge as it is known as the most critical carbon-generating process. Traditionally, raw coal materials were charged into the sintering machine through a straight inclined chute, resulting in the insufficient materials segregation due to a lack of energy in the horizontal direction, consequently leading to more coal consumptions with less energy efficiency. This study aimed to reduce coal consumption and increase sintering productivity to enhance homogeneous segregation by maximizing the horizontal velocity of raw materials passing through the feeding chute. This research modeled a chute simulator using the cycloid equations since the cycloid curve is ideal for converting falling energies to horizontal energies. As a pilot test results, the horizontal velocity on a cycloid curved surface of the chute designed through a simulator is superior to that of a straight inclined surface. The simulator has been upgraded to model with an optimized chute surface profile with roll-type cycloid trajectory. This cycloid chute surface profile increased the segregation effect by inducing vertical vibration in the raw material layer passing through the chute. As a result of applying the model to the actual sintering plant of the P steel-making company in Korea, as a pilot case-study, the vertical segregation was improved by 81% compared to the conventional ones. Coal consumption efficiency with the cycloid chute profile was increased by stacking light coal in the upper layer and heavy ore in the lower layer, and as a desired result, sintering productivity increased by 0.91t/d/m2. In addition, the fuel consumption ratio with the modeled chute profile was reduced by 3.57 kg/ton-sinter, and CO2 emissions were reduced by about 67,000 tons per year. This study is unique in that it contributes practically to field operations improvement by applying the modeled and developed technology to a full-scale implementation gradually in iron and steel-making plants. It is expected that the expansion of the study results to other sintering process plants will contribute to maintaining future economic competitiveness and environmental carbon-naturalization policies.