Measurement of particle movement in a spouted bed using a new microprocessor based technique

Abstract

A new experimental technique for measuring particle cycle times, times of occurrence of particles at different levels, and particle velocities in the spout of a spouted bed is described. A magnetized marker particle and search coil or coils are employed together with a microprocessor system for ease of data collection and processing. The magnetic particles have the same diameter, density and similar surface texture to bed particles to ensure proper representation.Data is presented on distributions of cycle time and particle velocity and implied particle mass circulation rates at different levels in a spouted bed. Comparisons are made with photographic and laser-doppler anemometry techniques.On dCcrit une nouvelle technique expkrimentale pour mesurer la duree du cycle des particules, les temps d'apparition des particules ti diffkrentes hauteurs et la vitesse des particules dans le bec d'un lit << spoute B. On utilise une particule d'un marqueur magnktique, une ou des bobines de repkrage, un systeme de microprocesseur pour faciliter I'acquisition et le traitement des donnees. Les particules magnetiques ont le m h e diametre, la m h e densite et la mkme texture de surface que les particules du lit afin d'assurer une reprksentation juste.On prksente des donnkes sur les distributions des durees de cycle et les vitesses des particules et des donnies calculees de debits massiques de particules a diffkrentes niveaux dans le lit <( spout6 >>. Des comparaisons sont Ctablies avec les techniques d'anCmomCtrie laser-doppler et des techniques photographiques.

Measurement of Particle Velocities in Conical Spouted Beds Using an Optical Fiber Probe

“…Thus, Kmiec (1978) used shallow beds, and consequently, only a qualitative assessment may be made about the validity of eq 7, which provides values of the same order, although slightly smaller than the experimental ones of Kmiec (1980). The results of Waldie and Wilkinson (1986) are average values for the spout section at several levels, and they are lower than those calculated by means of eq 7.…”

Effects of Draft Tubes on Particle Velocity Profiles in Spouted Beds

“…The optic fiber probe is one of the most commonplace methods, which has been attempted by Benkrid and Caram, He et al, and Olazar et al, respectively, to measure the vertical particle velocities in both the annulus and spout of a CSB [15][16][17]. Some other techniques, such as the radioactive tracer technique [18], magnetized marker particle with search coils [19], and the X-ray emitting particle tracking technique [20], have also been employed in full CSBs to measure particle velocities. Day et al measured particle velocity in the spout with a high-speed camera, by tracking the motion of colored tracers and also in the annulus by directly using colored particles [21].…”

Measurements of local flow structures of conical spouted beds by optical fibre probes

“…Based on their description, the column was a half conical spouted bed. Waldie and Wilkinson (1986) measured average particle velocity at different heights in the spout by measuring the change of inductance of a search coil using a tracer particle with high electromagnetic permeability.…”