We have mobile machines of varying capacity in Aussy.

Commercial ones mounted on semi trailers do 25 T/hr.

For other cleaning jobs there are ones that use  [either individually or in combination]  -

indented screens [catching 'trough' adjustable to pick the grain you either want to keep, or the other you want to discard at the point each falls out of the indents.]

shaking sieves   [see next below!]

rotary seives [lots of different slot size, or shot hole size screens]

air blast.  [dust and light rubbish/chaff]

These are smaller = but last one I helped aa mate clean canola with was running 8 tonne/hr. Excellent job -  saved a heap in dockage/ buyer cleaning fees.

A few farms own their own - others [majority in our area] hire by the hour from a commercial cleaner.