A STEPPED, CONICAL, BRICK RETAINING RING- SYSTEM FOR ROTARY KILNS

When problems with the service lives of refractory linings occur near the outlets of rotary kilns they can usually be attributed to the stre ssing of the refractory lining as a result of axial thrust and torsion . In a rotary kiln these forces must be counteracted by appropriate re taining segments at the kiln outlet or by retaining rings installed in front of it. The refractory bricks butted against these retaining dev ices are subjected not only to pressure but also to shearing with pron ounced stress concentration. Refractory bricks can take high levels of pressure forces, but not shearing forces. The ability to accept press ure stresses is utilized in the conical retaining ring system. Two typ es of cone were developed with wedge angles of 10 and 20 degrees to de al with differing circumstances. The special refractory bricks are sea ted on these stepped metal segments, the number of which can vary betw een 3 and 8. With the conical stepped wedge system it has been possibl e to prolong the service life of the brickwork by two to six times.