A new self-cleaning Rotary Drum Screen separates solid debris from wastewater at high rates with low energy usage according to Munson Machinery Company. The unit contains a rotating cylinder constructed of wedge wire screen with a stationary doctor blade on the outside of the cylinder and an internal spray line. Effluent discharges from a head box, overflows a dam and flows onto the outside of the rotating cylinder, allowing water to pass through the wedge wire into the cylinder. The doctor blade scrapes sludge and debris collected on the outside of the cylinder, while an internal spray line dislodges particles blinding the screen. The separator is intended for sewage treatment, pulp and paper, rendering, pelletizing and other applications in which solids must be removed from slurries in high volumes. It is said to contain few moving parts and offer low investment, operating and maintenance costs while minimizing floor space and headroom requirements. Models are available with drums of 24 in. (610 mm) diameter in 24, 36, 48, 50 and 72 in. (610, 914, 1219, 1270 and 1829 mm) lengths, and with drums of 36 in. (914 mm) diameter in 96 and 120 in. (2438 and 3048 mm) lengths. Capacities range from 200 to 1000 gal/m (757 to 3785 l/m).