Verfahren und Vorrichtung zum Überwachen eines Partikelstromes in einer Leitung durch periodische Erregung

摘要

In a pipe containing a fluid wherein particles circulate, at least one detector is attached. The detector includes a cavity in fluid communication with the pipe by a vent whose section, at least at an opening for fluid communication with a pipe is of the same dimensions as that of the circulating particles. A periodic exciter such as a source of acoustical waves or a generator of the periodic motion piston type suitable for inducing alternate pressure variations in the fluid in the cavity is coupled with the cavity. The excitation frequency can be selected in keeping with a resonance frequency of the cavity. Signals representative of the pressure variations of the excited fluid, resulting from flowing of the particles past the opening of each vent are measured. Processing of the signals allows the velocity of the particles to be determined. Other parameters of the particles can be determined by means of two distinct detectors coupled with the pipe. The detector may be used for monitoring the flow of catalytic particles in continuous reforming plants, for example.