Impact of Flow Boiling on Blast Furnace Tuyere Life: A Designer's Perspective

Abstract

Water‐cooled copper tuyeres of blast furnace are subjected to intense thermal conditions. Several modifications are attempted to prevent tuyere failure as the impact of failure is severe. What has, however, gone unnoticed is the peak “Cold face” temperature in tuyere and its implication. Numerical model incorporating water flow and conjugate heat transfer with a feature to identify onset of boiling by analytical correlations is developed. It is ascertained that, in tuyeres, the temperature of the Cold face exceeds the saturation temperature at the prevailing pressure by an amount high enough to cause nucleate boiling. The implication of the onset of boiling is discussed and a design modification is suggested by changing the aspect ratio of cooling passage. The impact of velocity distribution to achieve lower peak “Cold face” temperature is discussed. Modified design shows almost zero boiling prone zone for the range of operating parameters studied. Fourteen modified tuyeres are placed alongside original designed tuyeres in an blast furnace. The newly designed tuyeres outperform their counterparts. This approach to identifying and suppressing boiling of water in the cooling channel—a hitherto neglected phenomenon—gives an additional input towards designing a more robust tuyere.

Analysis of Erosion Mechanism of Wear‐Resistant Layer in Large Blast Furnace Tuyere

“…Different water chambers and spiral cooling water channels with different cross sections in tubular‐type tuyere are designed to match the intensity of heat load, ensuring a reasonable velocity distribution of cooling water and a good cooling effect. [ 6 ] Therefore, tubular‐type tuyeres are commonly used in China. The working environment of the tuyere is extremely harsh.…”

Optimization Study of Annular Wear-Resistant Layer Structure for Blast Furnace Tuyere

“…One method is to enhance the tuyere small sleeve's heat dissipation capability at the front end by optimizing the water structure inside the tuyere. Rajeswar Chatterjee et al [9][10][11] successfully extended the lifespan of the tuyere small sleeve by three months through numerical simulation to optimize the aspect ratio of the front-end cooling water pipeline, strengthening the front-end water velocity to reduce the occurrence of film boiling phenomenon. In addition, Guo X.P.…”