Numerical Modeling of Direct Current Plasma Versus Natural Gas‐Heated Steelmaking Ladles: Validation via Full‐Scale Industrial Measurements

Abstract

Conventional preheating methods for large steelmaking ladles typically use natural gas or liquified petroleum gas burners, which often have low thermal efficiencies depending on the fuel and oxidizer used. Common issues with these burners include lower overall bottom ladle temperatures and initiating decarburization in newly lined ladles with carbon‐rich refractory materials caused by the entrainment of air and combusting by‐products. In response to these issues, this study investigates the feasibility of using DC plasma torches for ladle preheating with nitrogen as carrier gas. Numerical models are developed to simulate ladles preheated by plasma torches, considering two variations: a 0.7 and a 1.5 MW torch. Additionally, a comparative model for a natural gas‐heated ladle is developed. The numerical results show that ladles heated by plasma torches achieve higher overall bottom temperatures due to strong convective heat flux, with average bottom temperatures of 983 and 1402 °C for 0.7 and 1.5 MW torch respectively, compared to 874 °C for natural gas heated ladle. The developed models are validated with industrial measurements on full‐sized ladles, confirming the feasibility of using plasma torches for preheating steelmaking ladles to temperatures similar to or higher than those achieved by conventional gas burners.