Via Cancelliera,10 – 00041 – Albano Laziale (RM)

Peripheral Drive Scraper Bridge

Peripheral Drive Scraper Bridge

PRTP series. The bridge is installed on a circular basin with a tower and central scum box for removing the sludge. It is used in those cases where suspended particles in sewage need to be separated and removed by gravity.


The water and sludge mixture from the central tower is diverted by a baffle cylinder to let the sediment solids settle at the bottom. Scraper blades convey the precipitated sludge to the central cone in the tank where they are then extracted with a pump. The clarified water flows in the channel around the top perimeter of the tank. Any floating materials are trapped by a blade in the spillway and taken to a collection and discharge tub.


– BRIDGE DECK with accidental overload 250 kg/sqm, max deflection 1/500 of the span, resting on a steel rotating support at the centre and, at the side, on a trolley with rubber wheels;
– CENTRAL SUPPORT with thrust bearing, lubricated with grease and mounted on a fixing plate, and horizontal pins for attaching and supporting the mobile bridge deck;
– CENTRAL BAFFLE AND SETTLING CYLINDER made of galvanized steel, anchored to the central plate with threaded rods;
– PERIPHERAL DOUBLE-AXIS DRIVE TROLLEY made of carbon steel, with polyurethane coated iron wheels, shafts and wheel holders and supports;
– BOTTOM SCRAPER ARM consisting of a set of vertical tubular supports attached to the mobile bridge deck; hinged at the ends of the supports are profiles on which are attached a logarithmic spiral blade and the travelling wheels. The height of the blade can be adjusted according to the gradient of the bottom;
– REPLACEABLE SCRAPER PLATES made of acid-resistant neoprene rubber.
– DISTRIBUTION MANIFOLD of loop design, with brush holder, brushes and terminals for connection to the geared motor (consisting of a central rotary manifold with plastic protective base and rainproof cover);
– GEARED MOTOR connected directly to one of the wheels of the trolley;
– SURFACE SCRAPER, Thompson profile, collection and discharge tank of the scum box with supporting brackets.


– REINFORCED BRIDGE DECK made of electrically welded carbon steel profiles and cold pressed sheet metal; walkway consisting of galvanized grating, parapets and toe plates, in conformity with ISPESL standards;
– CENTRAL BAFFLE CYLINDER made of hot-galvanized carbon steel;
– QUAYS and BOTTOM SCRAPERS made of hot-galvanized carbon steel;
– DRIVE WHEELS made of iron with polyurethane coating;
– TRAVELLING WHEELS made of nylon;
– THOMPSON PROFILE, skimming device and scum box made of AISI 304 stainless steel.