Dutch equipment manufacturer Brabant van
Opstal has developed a hammer mill that can run at 3,000 rpm and at 1,500 rpm.
The high speed is used for grinding difficult single raw materials and the
lower is suited for grinding a raw material mix, which ingredients have
different characteristics. The advanced controlled feeding ensures optimum
grinding.
This article can also be found at Feed Tech, volume 9, no. 4
FT_9.4_2.pdf