THE DUO-BALL-MILL-SYSTEM - RENAISSANCE OF THE BALL MILL IN 2-STAGE CEMENT GRINDING

The production of new types of cement of greater fineness meant that t he Otterbein cement and lime works in Grossenluder-Mus, Germany, had t o increase the throughput of the existing cement grinding plant. The t ask was to increase the existing grinding capacity by at least 30% by capital investment in an extension. Based on, extensive theoretical an d practical investigation a Scheme was worked out to implement the req uired increase in throughput by using two ball mills operated independ ently of one another. A patent was filed for this plant configuration, which was named the Duo Ball Mill System. A description is given of t he completed plant configuration and of the experience after a three-y ear operating period, and information is also provided about the histo rical development of two-stage Cement grinding in ball mills. The expe rience with the Duo Ball Mill System has been entirely positive. The g rinding operation is problem-free in every respect-including from the standpoint of operational reliability. Increases in throughput of more than 50%, depending on the product type, are being achieved and at th e same time there is a saving in power.