Sorry about that. here they were used to fill verticle silos with chopped corn or whatever. The fan is up to36" in dia. and was usually powered with a pulley/belt drive and would blow the corn up a 8"+or- pipe. We used to fill a small 25' silo with a belt from a Modet T Ford then went an 8N, what a difference!
There are lots of them here in scrap piles since most farmers use bunker storage for chopped hay and silage. bcs