Rim-Flo® Circular Clarifier

The Rim-Flo® clarifier is a peripheral-feed, peripheral-overflow circular clarifier designed for optimum activated sludge secondary settling tank performance.  Because of its hydraulic efficiency, a Rim-Flo clarifier can be designed with as much as 50 percent less surface area than a conventional center feed clarifier, with a corresponding decrease in cost.

The Rim-Flo also makes full use of its tank volume by eliminating short circuiting.  Locating the influent and effluent channels around the tank periphery permits effective skimming of the entire tank surface as well as the influent raceway.

More than 650 basins around the world ranging in size from 15m (50ft) to 67m (220ft) have been equipped with Rim-Flo peripheral feed channels.

• Channels - varied cross section maintains constant velocity, prevents deposition of solids; confined influent assures controlled headloss; peripheral effluent reduces short circuiting and makes weir and channel cleaning easy 
• Orifices - correct size, length and spacing eliminates ‘jetting action’ into basin and spiral flow vectors; spacing prevents solids deposition and permits equal flow distribution around tank periphery
• Influent skirt baffle - extends five feet below water surface to define clear liquid zone; allows low inlet velocities, defines inlet completely around the periphery for uniform flow distribution
• Raceway scum removal - scum is concentrated in a small area easily accessible from outside the basin

  Click here for a narrated presentation on the benefits of Rim-Flo circular clarifiers

Bulletins:
Rim-Flo® Clarifiers

Testing report:
Rim-Flo Clarifier at Neuse River Wastewater Treatment Plant Pass Field Test With Flying Colors