Process and device for cold milling

US4962893A · kind A · utility

Assignee

• Messer Griesheim GmbH · DE

Inventors

• Klaus Bochmann · Wiesbaden, DE
• Hans-Joachim Risto · Ludwigshafen, DE
• Wolfgang Volker · Tönisvorst, DE
• Helmut Gursky · Frankfurt, DE
• Dieter Steidl

Key dates

• Filing date: Oct 2, 1989
• Grant date: Oct 16, 1990
• Expiry date: Oct 2, 2009

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S241/37
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

Fluidized-bed counter-jet mills are gas-jet mills with which extremely fine milling results can be produced with very little wear and tear. An improvement in the milling results can be achieved by cooling the gas jets with a refrigerant, but the improvement that can be achieved is not substantial and the consumption of refrigerant is very high. In order to lower the consumption of refrigerant while considerably improving the fineness of the milled material, the coarse material which is separated by the grader of the mill is cooled by the refrigerant within the fluidized-bed counter-jet mill and fed back into the milling chamber. Liquid nitrogen is the preferred refrigerant with which the sump of the mill is cooled.