DESCRIPTION AND WORKING PRINCIPLES

This unit can be installed in a rectangular basin for removing particles of sediments and floating material in sewage. The sewage inlet is in one of the short sides of the tank. Air passes through porous ceramic filters in the tank encouraging the sediment substances to settle. The bottom scraper turns in the opposite direction to that of the sewage inlet to move the sand into a scum box. The forward limit switch signals the movement control unit to reverse direction and, at the same time, the scraping blade lifts up from the bottom while the surface scum blade moves down and conveys the oil to the skimmer. The return limit switch restores the previous condition. The water is in this way cleaned of most of the suspended solids in the channel.

MANUFACTURING FEATURES

• Bridge deck with accidental overload 250 kg/sqm
• Max deflection 1/500 of the span, made of carbon steel and with galvanized screen walkway, tubular railing with handrail and footguard, in conformity with safety standards, and entirely made of carbon steel;
• Trolleys made of carbon steel profiles, with polyurethane coated iron wheels of which two are geared and two are idler;
• Anti-slip wheels coupled in the sliding profile;
• Double blade made of steel tubes for collecting scum on the surface;
• Bottom scrapers consisting of blades supported by nylon travelling wheels. The scraper is connected to the bridge by means of steel tubes with adjustable joints;
• Replaceable scraper plates made of neoprene rubber;
• Microbubble diffuser tubes made of selected silica sand and epoxy binder;
• Bridge moving unit with worm geared motor directly connected to the driving gears;
• Control unit for lifting the bottom scrapers and the skimming blade, consisting of a worm geared motor or, on request, a control unit and oil hydraulic piston;
• Scum-box for collecting the scum, in stainless steel;
• Limit switch.
• Bridge deck made of hot-galvanized carbon steel;
• Droplegs, bottom and surface blades in stainless steel;
• Walkway, handrail and footguard made of hotgalvanized steel;
• Replaceable scraper plates made of neoprene rubber.
  A vacuum version is available on request which has air-lift or electric pumps.
• Also available on request is a mobile power control board with festoon cable:
• Power supply with festoon line, inclusive of cable, supporting poles, cable trolleys, cart for cable drive, terminal clamp, limit switch and power cord;
• Control board, watertight in design, for powering and controlling the equipment, with main switch, auxiliary power transformer, reversing devices, buttons for running the motors in automatic and manual mode, LEDs, an anti-condensation heating element and various accessories.