Ovivo® Bridge Supported Clarifier

Ovivo® bridge supported clarifier units have their sludge removal system hanging from a structural bridge spanning the tank. Wastewater enters through a side feed pipe into the center feedwell. The feedwell boosts flocculation of the suspended solids, which flow out into the clarifier to create a sludge blanket on the tank bottom. Rotating rake arms can be equipped with plow blades, spiral blades or suction ducts to remove the sludge, while a skimming device collects the scum at the surface.

The bridge supported clarifier is installed for the purpose of continuously removing substantial solids from a flow of trade waste.

The mechanism can remove precipitates after chemical treatment and before sand filtration. It is also used for pre-sedimentation of turbid or muddy water, coarse or fine screening, shredding or grit removal, for sedimentation of activated sludge after aeration, or for settling out the humus in the effluent of trickling filters.

  • Low maintenance
  • Trouble free installation
  • Long lasting design
  • High sludge concentration
  • High quality effluent
  • Low operator attention

The Ovivo® bridge supported clarifier (BSC) provides a concentrated bio solids and high quality effluent.

The bridge supported clarifier can be provided in numerous sludge collection configurations to address a customer’s specific needs or preferences. This mechanism is available in conventional plow blade, spiral rake blade, suction duct header and suction tube sludge collection designs.

Ovivo circular clarifiers have been used in clarification for over 80 years, providing consistent and reliable results for numerous applications throughout the industry. The Ovivo cast-iron, oil lubricated drives are the best choice for long life, low maintenance, and dependable equipment in the harsh atmosphere of wastewater and industrial applications.

Ovivo’s clarifier design provides trouble-free and quick installation. The variety of options available and Ovivo’s clarification experts will help you select the right equipment for your specific application.

The bridge supported clarifier mechanism uses the fundamental principal of gravity separation of solids from liquid to produce a clarified overflow water and sludge. The sludge accumulated at the bottom of the clarifier is then scraped or sucked out and removed for further processing.

The clarifier mechanism is supported from the tank wall by a bridge or truss system which spans the tank. The drive is mounted to the supporting structure and the rotating clarifier mechanism (torque shaft, feedwell, rake arms) hang from the drive.

Mixed liquor enters the clarifier horizontally through the side influent pipe and is discharged into the feedwell, which promotes flocculation of the mixed liquor suspended solids. It allows for a gradual redirection of the flow velocity into the clarifier and the sedimentation of the flocs creating a sludge blanket at the bottom of the tank.

Ovivo’s cast-iron, oil lubricated drives are equipped with bearings, worms and pinion mounted on a precisely machined surface. In every drive a high quality solid pinion maintains alignment and gives better resistance to bending and deflection under loads. Mating parts are machined to precise tolerances to assure precise fit and alignment. Every drive part is fully restrained (top and bottom) with no overhung loads. Main bearings are fully restrained into base. Worm gear reducer, single solid pinion, single solid worm / worm shaft and main gear all meet the latest AGMA (American Gear Manufacturers’ Association) standards.

Each drive is equipped with an overload control device activated by thrust from the worm shaft. This drive control includes a clear plastic enclosure and a weatherproof enclosure of epoxy coated aluminum construction with electro-mechanical switches.

Mechanisms are available in A36 steel, hot dip galvanized steel, 304 stainless steel and 316 stainless steel.

During winter in the Northern United States we experience icing problems with our clarifier’s conventional scum collection system and have to lock out the skimmer. If we don’t lock out the skimmer it is bent during heavy icing conditions. Is there a better solution?
Ovivo’s “full trough skimmer” is a full radius (the space between the feedwell and the scum baffle) scum trough and scum skimmer system. The skimmer system is neoprene curtain hanging from a rotating cantilever support beam. With two skimmer arms, the entire clarification surface between the feedwell and scum trough is swept into the radial scum trough twice per mechanism revolution. Because the neoprene wiper merely hangs from the cantilevered support, the skimmer will travel over any ice which has formed on the liquid surface.


What life expectancy can I expect from the clarifier drive?
Ovivo’s clarifier drives typically last more than 30 years. We have seen some clarifiers running with drives that were more than 35 years old!


We are trying to decide on whether to use a column supported clarifier or a bridge supported clarifier. Is one better than the other?
Based only on cost, a bridge supported clarifier is more economical at about 50 ft diameter and below. Column supported clarifiers tend to provide better cost at 40 ft diameter and above. Yes, there is an overlap between 40 and 50 ft diameter. Site, project and process specific conditions may be factors which need consideration when choosing between the two types of clarifier. This should be discussed with Ovivo or your local Ovivo Representative. We would be happy to assist.
  • Clarifier sizes: 15’ to +100’ diameter
  • Drive design: cast iron base, time tested strip liner bearing, solid deep gear, oil bath lubrication, up to 35 years of service
  • Drive torque capacity: 3,000 ft-lbs to 400,000 ft-lbs AGMA 20 years continuous torque
  • Rotation speed: 8 to 14 fpm, variable speed available
  • Available mechanism fabrication materials: A36 steel, hot dip galvanized steel, 304 & 316 stainless steel
  • Scum skimming design: conventional scum box, full trough skimmer, rotating pipe skimmer
  • Tank configuration: accommodate existing and new tank, steep to flat tank bottom, shallow or deep side water depth