Fu-You Tian’s research while affiliated with Zhejiang University and other places

The knowledge on pressure drop over the packed layers of sintered ore particles (SOPs) is deemed essential to have a deep understanding on the flow and heat transfer in emerging vertically arranged sinter coolers for waste heat recovery. In this work, the wall effects on pressure drop over a packed bed of SOPs were studied experimentally. Experiments for SOPs with bed-to-diameter ratio ranging from 7 to 35 and glass beads with the ratio between 6 and 22 were performed. The results revealed that the voidage effect tends to be pronounced for relatively low ratio values, while the friction effect becomes more significant for relatively high ratio values when it is lower than 40. Comparing to the confining walls, the particle characteristics were shown to have a dominant effect on the flow regime in the voids of the SOP-filled beds, whereas an opposite comparison was observed for the smooth glass beads as a reference. The correlations for the wall corrected friction factor proposed in the literature (Exp. Heat Transfer 12 (1999) 309), with varying coefficients, fit well to predict the pressure drop through packed beds for both glass beads and SOPs with considering the wall effects. Improved correlations were also proposed for spherical particles, SOPs and their blends with fairly good predictive accuracy.

The pressure drop over a packed bed with sintered ore particles was studied experimentally. The sintered ore particles were characterized to determine their equivalent particle diameter, bed voidage, and sphericity. The pressure drop experiments were performed on unsorted and sieved particles with various size distributions for a superficial velocity up to 2.4 m/s, covering flow regimes from laminar to turbulent. It was shown that the Ergun equation underestimates the pressure drop for such highly irregular-shaped particles by about 40%. The measured modified friction factor was well correlated to a scaled Ergun equation, which was verified to be valid for the modified particle Reynolds number up to 12 000 toward design and optimization of vertically arranged sinter coolers for waste heat recovery.

Waste heat recovery from sintered ore particles (SOPs) is deemed to be a promising approach to improving the thermal efficiency in iron and steel industry. In this work, industrial SOPs sampled from a steel plant were characterized to obtain a comprehensive set of fundamental structural and thermophysical properties. The SOPs investigated were identified as self-fluxed sinters having a basicity of 1.175 after composition analysis, and two peaks were observed on the pore size distribution. The specific heat capacity of the SOPs at elevated temperatures up to 200 °C was measured, with a power-law fit curve being established for extrapolation to higher temperatures up to 900 °C. The thermal conductivity of the SOP samples with various porosities was determined experimentally, while a Sierpinski-carpet-based fractal model was also utilized to predict the effective thermal conductivity as a function of porosity. The fractal model was validated by the experimental results, which can be applied over a wide range of porosity.