Automatic particle-size analyzer
AssigneeWeyerhaeuser Company
InventorGevan R. Marrs
Life of this patent
Estimating the term…
Abstract
The invention is apparatus which can automatically make a screen analysis of a granular material. The heart of the apparatus is a polygonal drum having graded screens on each of the faces except one. This open face serves as a door for introducing a sample into the interior of the drum and for discharging any material larger than the largest screen. A gear motor and crank arrangement serves to longitudinally shake the drum and agitate the sample. A second gear motor indexes the drum from screen to screen after a predetermined shaking time. Each screen fraction is accumulated on an electronic scale with weights being determined by differential weighing. The gear motors are timed by a microprocessor which also receives screen friction weight inputs and calculates a screen analysis.
Claims8
A particle-size analyzer which comprises:
- a. a polygonal drum means having a plurality of longitudinal faces on the periphery of said means;
- b. a plurality of screen means mounted on the faces of the drum means for classifying a particulate sample into size groups, said screen means being successively graded from relatively smaller to relatively larger openings;
- c. a door means for introducing a sample to be analyzed into the interior of the drum;
- d. indexing means for successively rotating the drum about its longitudinal axis in angular increments so that each screen in turn is located as the lowermost face of the drum;
- e. shaking means giving reciprocal motion along the longitudinal axis of the drum in order to agitate a sample being analyzed;
- f. control means which determines shaking time for each screen means and directs the indexing means to rotate the drum to a next larger screen size after a predetermined period of shaking, and
- g. means for collecting successive screen fractions of the sample being analyzed.
Dependencies are inferred from the claim text.