| CPC B07B 1/4636 (2013.01) [B07B 1/4627 (2013.01)] | 19 Claims |
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1. A method for screening material in a sieve system, comprising:
a sieve for screening material by selectively passing first particles of the material and not passing second particles of the material based on respective dimensions of the first and second particles relative to dimensions of screening apertures in the sieve;
a holding container for feeding material to be screened to the sieve; and
a fines container for receiving the first particles screened by the sieve, the method comprising:
measuring a first fines container load at a first time;
measuring a second fines container load at a second time;
determining a fines rate by determining a rate of change of the fines container load based on the measured first and second fines container loads and the first and second times;
determining an operating condition of the sieve system based on the determined fines rate; and
determining that the fines rate is equal to or greater than a fines rate high set point and determining the operating condition to be representative of a damaged or missing sieve wherein the sieve system further comprises an oversize container for receiving the second particles from an oversize discharge outlet, and the method further comprises:
measuring a first holding container load, a third fines container load, and a first oversize container load at a third time;
measuring a second holding container load, a fourth fines container load, and a second oversize container load at a fourth time;
determining a sieve load based on a difference between a) a decrease in the holding container load between the third and fourth times, and b) a sum of an increase in the fines container load and an increase in the oversize container load between the third and fourth times; and
if the sieve load is equal to or lower than a sieve load low set point, determining the operating condition to be representative, or further representative, of an underloading of material on the sieve, and
if the sieve load is equal to or greater than a sieve load high set point, determining the operating condition to be representative, or further representative, of an overloading of material on the sieve.
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