OVIVO® Thickener

The Ovivo® sludge thickener is designed to continuously produce as thick a sludge as possible from streams of sludge previously formed and collected in separate settling basins. Included with the thickener mechanism are Ovivo's durable heavy-duty drives. The drive is designed to handle the specified torque for 20 years of continuous operation, but we have seen drives still in operation after over 35 years of service.
  • Bridge or column supported gravity thickening of solids
  • High sludge concentration
  • High quality effluent
  • Low maintenance
  • Low operator attention

Ovivo® bridge supported and column supported gravity thickeners provide high sludge concentrations and low solids effluent.  The thickener mechanisms are robustly designed for long dependable life and can be tailored to a specific process.  Ovivo thickeners can be used in new construction or designed to fit into existing tanks.


  • Bridge or column supported gravity thickening of solids
  • High sludge concentration
  • High quality effluent
  • Low maintenance
  • Low operator attention

Ovivo thickeners are available in two types: CST (column supported thickener) and BST (bridge supported thickener). The thickeners can be tailored to meet the specific demands of a customer’s process. They can also be designed to fit into new or existing thickener tanks.

Ovivo circular thickeners have been used in thickening for over 80 years. They present 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 thickener design provides trouble-free and quick installation. The variety of options available and Ovivo’s thickening/clarification experts will help you select the right equipment for your specific application.    

  • Clarifier sizes: column supported: 20’ to +200’ diameter; bridge supported: 10’ 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

The Ovivo® thickener mechanism uses the fundamental principal of gravity separation of solids from liquid to produce a clarified overflow water and sludge. The sludge or minerals enter the thickener though the column or a side influent pipe and then into the feedwell. The feedwell baffles further slows the influent flow speed and allows the heavier solids to settle to the tank floor while the clean effluent passes over the tank weir and onto further processing.

The settled solids are thickened as they are scraped towards the center of the tank and are collected in a sludge hopper or pit where it is pumped from the tank for further processing. To assist in the thickening process, the gravity thickener rake arms are supplied with pickets to help maximize solids concentration. 

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.

Is there a thickener design to handle a high flow, high capacity influent stream?

Yes, Ovivo has high-capacity thickeners with patented feed dilution system options designed to maximize flocculation efficiency, self-dilution and settling rates. Ovivo high-rate thickeners are designed to provide roughly 12 times the throughput of conventional machines of similar size.

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 thickener or a bridge supported thickener. Is one better than the other?

Based only on cost, a bridge supported thickener is more economical at about 50 ft. diameter and below. Column supported thickeners 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 that need consideration when choosing between the two types of thickener. This should be discussed with Ovivo or your local Ovivo Representative.

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