Quantification of the heating rates of particles in laminar iron dust flames via a Multi-parameter diagnostics approach

The utilization of iron powder as a recyclable, carbon-free chemical energy carrier requires a fundamental understanding of flame stabilization mechanisms, which are governed by key parameters such as the particle heating rate. This study presents a novel experimental approach to quantify particle heating rates in laminar iron dust flames. By combining multi-planar Particle Image Velocimetry (MP-PIV) with simultaneous luminescence tomography, the instantaneous particle flow field and flame topology were reconstructed in three-dimensional space. This allowed for the precise determination of the pre-heating zone’s leading edge (PHZ) and the calculation of particle residence times between the leading edge of the pre-heating zone and the iso -surface of the maximum ensemble particle temperature. Combining this flow field data with spectrally resolved pyrometry measurements, mean particle heating rates were derived for iron dust flames with oxygen concentrations of 30 vol% and 40 vol%. The results reveal heating rates in the range of 3.1 × 10 5 K s −1 to 4.1 × 10 5 K s −1 , respectively. Oxygen enrichment was found to increase the maximum ensemble particle temperature, T p , m a x , from 2300 K to 2400 K. The presented dataset provides the first experimentally in-situ determined particle heating rates in a self-sustaining iron dust flame, serving as a crucial benchmark for the validation of numerical models describing particle group combustion effects.