FloatSep™

DESCRIPTION

The FloatSep™ design takes advantage of complex hydrodynamics to consistently direct floating solids to treatment and allow clear flows to overflow to the outfall. The baffles produce a powerful vortex that ‘flushes’ the buoyant materials from the surface of the regulated chamber and draws neutrally buoyant materials that would otherwise overflow the control weir.

APPLICATIONS

In combined sewer systems:

  • CSO control structure treatment
  • Retrofit overflow structures before net systems
  • Any location that accumulates floatables

For separate sanitary sewer or combined systems:

  • Offline storage facility pretreatment to reduce maintenance costs and frequency
  • Tunnel storage pretreatment to reduce build-up of debris in the tunnel

ADVANTAGES
  • Costs only a fraction of other treatment technologies
  • No head loss—zero impact on HGL
  • Requires no external power—works off of the energy of the flow in the sewer
  • Reduces mainentance requirements in the overflow control structure
  • Installs without major structural modifications
  • Reduces storm water-related problems for your city's administration
  • ARRA compliant—made in the USA
HOW IT WORKS
  1. In the CSO chamber, a horizontal baffle is installed to keep materials from reaching the chamber’s existing control weir, and a vertical baffle is added to facilitate the generation of a vortex that draws all solids to the controlled outlet of the structure.
  2. When properly designed, the vortex that is generated increases in force as the rate of overflow continues. This vortex not only draws floating materials from the surface of the regulator, but also inhibits the flow of these materials under the horizontal baffle, improving the capture of materials that would otherwise be released to the receiving waters.

PERFORMANCE

The FloatSep™ baffle system was tested at six locations in Japan, First, the loss of suspended solids over the control (overflow) weir was quantified during different overflow events prior to FloatSep™ baffle installation. Then, the test was repeated during similar overflow events after baffle installation.

  • Prior to installation, over 90% of the solids in the sewer were going with the overflow over the weir.
  • After installation, the results were reversed—more than 90% of the solids were captured in the underflow into the interceptor.

The performance is consistent over a wide range of storm conditions. Removal efficiencies have been monitored for
several generic compounds, including plastics, FOG (fat, oil,
and grease), wood materials, rags, and stringy materials. Removal efficiencies are shown below for varying overflow
rates. The ‘design flow’ is assigned a relative value of 1Q,
and represents the rate at which 85% of annual overflow volume falls below that flow rate. (In many parts of the U.S.
this is the equivalent of the runoff from a storm intensity of
one inch per hour.) Removal efficiencies are then shown for flows that represent .5Q, 1Q, 1.5Q, and 2.0Q. The horizontal baffle is sized such that flows greater than 2.0Q will top the baffle, which in effect becomes a submerged weir. This
prevents excessive head loss and potential up-stream flooding.

A detailed report of this testing is available at
your request.