1 - the capacity of the screen is obviously directly related to the free area of the drum or cloth. To double capacity provide twice the area

2 - There is an old guidline that if you plot the particle size distribution on log-log paper the underflow will look very much like the feed, but shifted to the lower d50 range. So providing more coarse feed will result in a similar but coarser underflow.

3 - To quantify finer points of screen technology requires testing - full scale or lab tests. You should be able to set up a small model in the lab to compare ideas (the soils engineers do that as a matter of routine). ■

More OPEN AREA = More TPH thruput with the same square footage.

CLEAR OPENINGS mid range wire diameters are typically used for aggregate screening. Midrange meaning with get a decent return on our investment dollar and decent life before having to replace it.

Long slot or super long slots give much more O/A and more TPH thruput but, may equate to SHORTER life of the wirecloth as a tradeoff. Ordering wirecloth, properly fabricated to have the cross wires lay ontop of the support rail rubbers will increase TPH vs just ordering to fit the width of the screenbox and having the cross wires lay just anywhere and be an interference fit for material trying to PASS THRU THE OPENINGS.

FOR COARSER feed gradations in a particular feed mix, just use the VSMA FORMULA which will tell you the efficiency rating of that particular screening job, taking into consideration your exact FEED MATERIAL SIEVE ANALYSIS. ■