I got asked to design a filtering device that could filter a mixture of flour, rice, sugar and peanuts?

Drop the mixture from a height into some water and blow of the flour into scoop as it drops.

The peanous will float - scoop them off.

The sugar will dissolve - drain off the water.

The rice will be at the bottom - so collect it.

Messy and not perfect for the product- but more novel and interesting than the boring filter screens!

Screens of appropriate size will separate all but the flour from the sugar. Those or the whole batch need to pass over a blower to blow the light flour off the heavier sugar.

IT JUST NEEDS THREE FILTERS.

[1] A FILTER WITH BIGGER HOLES THAT JUST ABLE TO BLOCK THE SIZE OF PEANUT ,PLACING IT AT THE TOP.

[2] THE SECOND FILTER FROM TOP WITH SMALLER HOLES THAT JUST ABLE TO BLOCK THE SIZE OF RICE.

[3] THE THIRD FILTER WITH SMALLEST HOLES THAT JUST ABLE TO BLOCK THE SIZE OF SUGAR.

WITH THESE 3 FILTERS LINE UP TOGETHER, FLOUR GOES THROUGH ALL OF THEM AND SETTING AT THE BOTTOM.

Try a series of screens on a shaker. They have used these in grain mills.

It will cost you some $$$$