Method and apparatus for dry particle analysis
First Claim
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1. A dry particle analyzer comprising:
- means for drizzling particles from a bulk sample thereof, means for providing a downward flow of first sheath ambient air around said drizzling particles, means for downwardly columnating the first sheath air flow and drizzling particles, means for providing a downward and columnar flow of second sheath ambient air around said columnated first sheath air and drizzled particles and substantially in velocity union therewith, and means defining a vertically downwardly extending optical analysis cell passage receiving the unified downward flow of drizzled particles and first and second sheath air for columnated downward flow therein, whereby the drizzled particles flow downwardly continuously from said bulk sample and through said analysis cell passage means.
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Abstract
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.
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Citations
21 Claims
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1. A dry particle analyzer comprising:
- means for drizzling particles from a bulk sample thereof, means for providing a downward flow of first sheath ambient air around said drizzling particles, means for downwardly columnating the first sheath air flow and drizzling particles, means for providing a downward and columnar flow of second sheath ambient air around said columnated first sheath air and drizzled particles and substantially in velocity union therewith, and means defining a vertically downwardly extending optical analysis cell passage receiving the unified downward flow of drizzled particles and first and second sheath air for columnated downward flow therein, whereby the drizzled particles flow downwardly continuously from said bulk sample and through said analysis cell passage means.
- View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14)
- 15. A dry particle analyzer apparatus comprising drizzling means for dispersing particulates from a bulk sample thereof downwardly at a selected metered rate, a conduit defining an upwardly open mouth receiving the drizzling particles and a first vertically downward flow of ambient sheath air, said conduit directing said particulates and first sheath air still further downwardly along a convergent conduit section, thereby effecting an increase of flow velocity through an externally surrounding plenum of second sheath air, said surrounding plenum providing an inlet through which enters ambient air and said plenum channels air therein downwardly therefrom through a plenum exit including a multi-cellular flow-columnator around the conduit, said conduit includes an elongate cylindrical flow-columnating exit portion extending through the flow-columnator, and each of said conduit and said plenum with flow columnator has generally the same total air flow resistance to produce substantially the same air flow velocity for both the first and second sheath air flows to provide a homogeneous descending column of air which includes a centralized flow stream of air with the drizzle of particles at a known location in the air flow column, and disposed below the convergent conduit and second sheath air plenum and in sealed relation with the latter is a planar analysis cell defining an air flow path generally of J-shape, the analysis cell defines a vertically downwardly extending analysis passage having opposite transparent windows for passage of test radiation beams perpendicular to the plane of the J-shape, and below the analysis passage the analysis cell includes side walls defining a sub-critical convergent-divergent venturi nozzle shape which turns the air and particulate flow 180 degrees at the bottom of the J-shape and leads upwardly as a divergent pressure-recovery diffuser to an exit port.
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20. A method of dry particle analysis, said method including the steps of:
- drizzling particles from a bulk sample thereof, providing a downward flow of first sheath ambient air around said drizzling particles, downwardly columnating the first sheath air flow and drizzling particles, providing a downward and columnar flow of second sheath ambient air around said columnated first sheath air and drizzled particles and substantially in velocity union therewith, uniting said first and said second air flows, defining a vertically downwardly extending optical analysis cell passage below and downwardly receiving the unified downward flow of drizzled particles and first and second sheath air flows for continued downward flow therein, and optically interrogating said drizzled particles in said analysis cell passage, whereby the drizzled particles flow continuously downwardly from said bulk sample and through said analysis cell passage.
- View Dependent Claims (21)
Specification