The friction drive for modern two-support kilns

The proper selection of critical drives in a cement plant is of the utmost importance as to how well the plant will function over its lifetime. The rotary kiln is at the heart of the cement making process. It is perhaps the single most critical piece of equipment in the cement plant. This paper introduces self-aligning kiln roller supports as an innovative drive technology for modern 2-support kilns. Such kilns are statically determinant and it is possible to drive the kiln´s rotation through its supporting rollers by means of this special roller design. As a consequence, the friction drive with AC variable frequency motors (or hydraulic motors) is quickly becoming the kiln drive of choice for all new 2-support kiln installations. This paper will examine the operating, maintenance, and cost benefits of the friction drive (such as the elimination of the traditional ring gear and pinion). It will be shown that the new drive system thereby eliminates the traditional problems of alignment, wobble and lubrication of the kiln girth gear. Additionally, the civil construction costs are minimized as the drive system does not require a separate foundation. It will be shown how the self-aligning kiln roller supports of a modern 2-support kiln will ensure reliable and efficient transmission of the driving power to the kiln under all operating conditions.