Oliver Manufacturing Vice President and Chief Engineer Jim Thomas has lent his expertise to write an article for the March 2009 Powder And Bulk Engineering International magazine titled An Introduction To Gravity Separators.  If you would like to review it please follow this link:  http://pbei022009.ecndigitaledition.com/magazine.aspx?eid=1525&e=36644180&b=152435
The article starts on page 18 of the magazine.