Q.What is the difference between the sludge ring and the sludge drum? Is there an advantage?

A.: he sludge ring is, very simply, a static ring anchored to the floor with multiple orifices spaced along its perimeter. Higher concentration sludge enters an orifice only where the spiral blade passes an opening, while sludge is sucked into all the ring’s orifices continuously. This may cause sludge dilution. The Sludge Drum is a dynamic enclosure which rotates with the rake arms. Because it rotates with the arms, the spiral blades are continuously feeding fresh concentrated solids into the drum adjacent orifice.