Horiba Instruments, Inc.

Steven C Mott

Craig A Wright

Jeffrey P Baker

A dry particle analyzer includes a vibrating sieve cup drizzling particles downwardly with first and second sheath air flows provided to separate the particles from boundary walls and to form the drizzling particles into a curtain for optical analysis. The particles drop vertically as a drizzle with gravitational assistance from a bulk sample to the analysis passage, after which their direction of movement is changed to horizontal and then upward for removal from the analyzer.

Method and apparatus for dry particle analysis

A particle analyzer includes a vibratory driver for particulate samples which are received in a sample cup to be drizzled under controller vibration to an analysis cell of the analyzer along with a conveying air stream. The driver is arranged to impose orbital oscillatory motion in a vertical plane on the sample cup to roll the sample while assisting in sifting of the sample through conventional sieve screen sample cups. Avoidance of vibratory classification of the sample by particle size while the test is in progress, as well as avoidance of sample compaction is achieved with the described driver. Additionally, an improved predictability of sample feed rate control results from the use of the orbital driver also with a novel sample cup not utilizing a sieve screen, but employing the inherent characteristic of particulate materials to form an repose angle when piled up. The novel sample cup provides a ledge surface upon which particulates are piled in their inherent angle of repose preparatory to being vibrationally dislodged and drizzled over an edge of the ledge. The repose angle of the particulates is continuously refilled from a bulk sample of the particulates as particles are drizzled to the analyzer. Structure is provided for adapting the sample cup to a variety of particulates, regardless of whether they be free-flowing or somewhat cohesive.

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San Diego, CA, United States of America

Steven C Mott