Single-shot planar temperature imaging of radiatively heated fluidized particles

A single-shot, non-intrusive planar technique for measuring the temperature of radiatively heated particles with good spatial resolution has been demonstrated. This technique has been applied to particles with diameters between 10µm and 50µm, suspended in a highly unsteady flow within a fluidized bed. The particles were heated with a high-flux radiation source to provide high and well-characterized heat fluxes ranging from 2.4 MW/m2 ≤ Ф ≤ 21.1 MW/m2. Each measurement is derived from two images with an area of 15mm × 10.8mm using an image splitter and a single ICCD camera. An average of 30 particles were recorded in each image with a spatial resolution of 51 pixels/mm. A maximum temperature rise of 350°C was recorded with a heat flux of 21.1 MW/m2, with a corresponding heating rate of up to 23,000°C/s, given the maximum residence time of the particles in the heating region of 0.05s. The normalized temperature distribution within an individual particle agglomerate was found to be up to ± 4%, which is attributable to ICCD noise so that the mean temperature is well resolved.