On-line measurement of particle size in industrial grinders

摘要

The solvent (1), eg. acetone, edible oils, is pumped from a storage tank (2) to the dispersion vessel (4) containing the sample of particles. The upward flow (7) of solvent produced by the pump (3) balances the gravitational force on the particles. A second pump (8) sucks the dispersed mixture via a retarding coil (10) in which particles a separated, to the measurement cell (9). The particles size is determined by a parallel light beam (13) and a CCD line sensor (12) to measure the light attenuation. After measurement the mixture is filtered by a suitable filter (18) and the solvent is pumped back to the storage container by a third pump (19). A heater may be integrated in the filter (15) to vaporise the solvent.