You can simulate your options with our DEM code ROCKY. See vibrating screen simulation at: www.conveyor-dynamics.com ■

Hello: the word screening when using the term 200mm (7.8") is not quite accurate, these sizes we would call scalping vs screening. Screening assumes 95% efficiency as per VSMA calcs, but, 30mm (1.18") is more correct.

Yes, big stones can make a problem, in this respect. Probably a much better idea to do the big scalping of larger stones on a separate screen, setup with a much large stroke to SCALP those biggies, probably with a heavy duty rubber and or perf plate with skid rails on it. Dropping minus 8" rock onto a 1" opening is not desirable at all either....much too abusive to the smaller diameter wirecloth. Would expect much shortened wirecloth life in that scenario.

Even at 1.18" you can or could use a standard woven wirecloth but, for me i would use a smooth top or flattop wirecloth wire the intersections of the wirecloth are all woven below the sliding rocks vs onto and in the way of the rock and subjecting the cloth to abuse.

hope this helps. George Baker, MODERATOR.

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Is there any relation between max. particle size and min. allowable aperture size?

for example:

max. particle size is about 200mm in feed and I would like to use a screen with 30mm cut size.

As I have calculated screen area acoording to VSMA, 1.8mx4.8m screen is suitable for 350 t/h(bulk density=2.3 t/m3) and bed depth will be about 80mm(less than 3 times of 30mm).

I have not seen any limitation in screen area and bed depth calaculation for max. particle size.

but:

when when we have stones of 200, 150 and 100mm in our feed is the bed depth calculated=80mm can be correct?

Can the big stones make problem in screening operation?[/QUOTE] ■