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

Peripheral Drive Vacuum Scraper Bridge

Peripheral Drive Vacuum Scraper Bridge

PRATP series. The bridge is installed on a circular basin with flat base and tower. 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 gather the precipitated sludge which then flow through intake pipes to a collection tub at the centre of the tank. The sludge are extracted from the tub with a siphon primed by a blower at a rate based on the amount of sludge involved. 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 rotating steel 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 ARMS consisting of a set of vertical tubular supports attached to the mobile bridge deck; at the end of the supports are “V-shaped” scraper blades fitted with the pumps required to intake the sludge;
– SET OF SLUDGE INTAKE PIPES with valves, collection tank and syphon;
– 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 (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 supernatant 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;
– THOMPSON PROFILE, skimming device and scum box made of AISI 304 stainless steel.