Experimental Investigation of Reactive-Inert Particulate Matter Detachment from Metal Fibres at Low Flow Velocities and Different Gas Temperatures

The detachment of particle structures from single fibres in gas flow has been investigated only for inert particle structures yet. This study investigates the detachment of particle structures containing reactive components. These reactive components disappear during the reaction and enhance detachment at low flow velocities. Soot was used as the reactive component and glass spheres as the inert component of the particle structure. The soot disappears due to combustion with oxygen leaving only the glass spheres on the fibre. Without reaction, the detachment phenomenon was observed at superficial flow velocities above 1.9 m/s and with reaction at 0.5 m/s. This shows that reacting and disappearing components of the particle structure can enhance detachment

A Novel Apparatus for Simultaneous Laser-Light-Sheet Optical Particle Counting and Video Recording in the Same Measurement Chamber at High Temperature

A novel apparatus was developed, to investigate the detachment of particle structures consisting of soot and ash from a single fibre or a fibre array in hot gas flow. Key features of the novel apparatus are operation at high temperatures while two different measurement techniques are applied simultaneously in the same measurement chamber to observe particle structure detachment from a loaded fibre array. A heated inlet can heat the air stream at the position of the fibre array up to 470 °C, allowing detachment investigations at temperatures relevant for the operation of, e.g., soot particle filters. The first measurement technique integrated in the setup is video recording of the fibre array, which gives qualitative information on the rearrangement or detachment of particulate matter on the fibre. Because it is often difficult to distinguish rearrangement and detachment from pure visual observations, a second measurement technique is applied. This technique is a laser-light-sheet optical particle counter, which can detect detached particle structures and determine their size. The measurable size range is 257 to 1523 µm for glass spheres. This paper presents and discusses the novel apparatus, its calibration and first detachment measurement results