DRY PROCESS GRAIN SIZE DISTRIBUTION-MEASURING APPARATUS

Japanese Patent JP3809099

B2

PROBLEM TO BE SOLVED: To provide a dry process grain size distribution-measuring apparatus that can disperse a particle sample whose dispersion limit has been 1 μm as a common sense in air dispersion conventionally to the state of fine particles whose grain size is submicron, and is capable of accurately measuring desired grain size distribution. SOLUTION: In the dry process grain size distribution-measuring apparatus, a sample 5 in a granular body shape is supplied to a flow cell 2 that is flowing in the air, at the same time the flow cell 2 is irradiated with laser beams, and the distribution of the grain size of the sample is measured on the basis of the detection output of scattered light and/or diffraction light due to the sample 5. In the dry process grain size distribution-measuring apparatus, the sample 5 that is supplied to the flow cell 2 is subjected to primary dispersion by a primary dispersion flow 30 reaching a critical pressure and a subsonic speed, and then is subjected to secondary dispersion by a secondary dispersion flow 31 that differs from the primary dispersion flow 30 in terms of the direction and at the same time and reaches a critical pressure and a subsonic speed.