That's like a miniature version of the 6 foot long wooden hand-crank winnowing rig in Grandma's barn when I was a kid. It oughta work if you play with the fan speed. Big investment though and another appliance taking up space. In the old days they used to separate the wheat from the chaff by throwing it up in the air on a windy day. The chaff would blow away and the denser grain would fall straight down to be collected.