Method And Apparatus For Determining The Relative Weight Proportions Of Different Size Fractions Of A Sample Of Particulate Material
A sample of particulate material is entrained in a moving body of fluid and the fluid is continuously discharged through a porous weighing member. Before passing to the weighing member sized fractions within the sample, except for the smallest one, are separated and held back at different regions in the body of fluid so that only the one fraction initially deposits on the weighing member. The weight addition of this fraction is measured and then a further fraction is re-entrained to move with the fluid to pass to and deposit on the weighing member cumulatively with the first fraction. The weight increase caused by this further deposition is measured and the re-entrainment and weight increase measurement of still further fractions are effected separately and successively until all fractions are deposited on the weighing member. These individual weights and their sum are recorded either manually or automatically and from them size percentages are computed. Further samples may be similarly processed while the weighing member accumulates all samples until its capacity is reached, whereafter the weighing member must be cleaned or replaced. The several size fractions may be separately recovered when a multiplicity of weighing members is employed.
- Georgia Tech Patents