What is this traditional Chinese farm tool called?

The windmill! Using wind power from hand cranking! Sifting grain! Look at the front to get out of the mouth is more full of particles, the back of the mouth out of the general is mainly fed to chickens and pigs! The last out of the gray a slag generally do not! There are techniques to shake the windmill. Too hard bar full of blow away, light and sieve not clean!