In the past several decades, refuse-derived fuels (RDFs)
have been
widely applied in industrial combustion processes, for instance, in
cement production. Since RDF is composed of various waste fractions
with complex shapes, its flight and combustion behaviors can be relatively
complicated. In this paper, we present a novel plenoptic camera-based
spatial measurement system that uses image processing approaches to
determine the dwell time, the space-sliced velocity in the depth direction,
and the ignition time of various applied RDF fractions based on the
obtained images. The image processing approach follows the concept
of tracking-by-detection and includes a novel combined detection method,
a 2.5D multiple particle tracking algorithm, and a postprocessing
framework to tackle the issues in the initial tracking results. The
thereby obtained complete spatial fuel trajectories enable the analysis
of the flight behaviors elaborated in the paper. The acquired particles’
properties (duration, velocity, and ignition time) reversely prove
the availability and applicability of the developed measurement system.
The adequacy and accuracy of the proposed novel measurement system
are validated by the experiments of detecting and tracking burning
and nonburning fuel particles in a rotary kiln. This new measurement
system and the provided experimental results can benefit a better
understanding of the RDF’s combustion for future research.