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Show Performance of Third Generation Rotary Kiln Incinerator John Petersen and Mike Keller Callidus Technologies Inc. a. Thermal growth and expansion of the kiln shell b. Variations in shell temperatures due to changes in ambient conditions and Normal refractory deterioration c. Wear on the kiln tires and trunnions which effectively lowers the rotating axis of the kiln It is important that the kiln seal surfaces be round and concentric to the kiln center lines. The only positive method to build this type kiln is to first design a structurally rigid unit and then place the kiln in a large lathe and turn the entire shell (Photo 1). First, the kiln must be constructed with sufficient stiffness to provide a stable mechanical design. The strength will be provided by a proper mechanical design including adequate plates thickness. In general, a kiln shell thickness should not be less than Ti = D/150 where Ti is the shell thickness in inches and D is the shell diameter in inches. The shell has additional stresses at the tire sections (Figure 2) and at the feed and ash disclosing point (Figure 2). The shell thickness near each tire is normally doubled to provide increased stiffness (and to minimize shell and refractory strains) directly under the kiln tires. Second, the entire kiln is placed in a large lathe and machined to make the rotating longitudinal axis, the shell tire sections, and the kiln seal surfaces dimensionally correct. With these steps in place, it is still necessary to design a seal that will allow motion in both the axial and radial directions. One approach to this challenge is shown on Figure 3. The seal system allows motion in two directions (axial and radial) and consists of carbon blocks held against a machined seal surface on the kiln. This design concept is very similar to disc brakes V-33 5 |