TRANSVERSE MOTION OF SOLIDS MOVING THROUGH ROTARY KILNS

The transverse motion of solids moving through rotary kilns is classified into two main categories. These categories are characterized by whether or not the frictional forces exerted by the material on the kiln wall are extensive enough for the material to maintain its position (relative to the wall) until its angle of repose is exceeded. On this basis the frequently observed rolling and slumping types of motion are classified together; the former representing the continuous aspect of this mode whilst the latter describes the discrete situation. An equation is derived which shows the degree of filling required to ensure that the material moves in the rolling/slumping mode, as a function of its angle of repose and coefficient of friction with the wall. © 1979.