Design, production and launch of turnkey RAS
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Marine Technology
Marine Technology
Aquaculture Engineering

Protein skimmer

Foam fractionation to remove dissolved organic matter (DOC), lipids and fine suspended matter before the biofilter. Reduces turbidity and odors, improves ORP.

Capacity: 10–150 m³/h Co-/countercurrent Ozone - option
Get specification More details
Productivity
10–150 m³/h
Mode
co-/countercurrent
Integration
ozone, coal, degassing
Protein skimmer

Replace protein-skimmer.jpg in the photo of your equipment.

Crystal water and load reduction

What does the equipment solve?

  • Removes hydrophobic DOC fractions and fine suspended matter before the biofilter.
  • Reduces the load on nitrification and oxygen consumption in the biophase.
  • Increases ORP, reduces odors and water coloration.
  • Works as a degasser: removing CO₂ and volatile compounds.

Equipment

  • Column made of PP/PVC/stainless steel. with Venturi injectors or sprayers.
  • Foam collector with level sensor, automatic draining and washing.
  • Inspection windows, inspection hatches, drain taps.
  • Control panel: flushing timers, level control, alarms.
  • Activated carbon cassette and degassing unit are optional.

How it works

Foam fractionation

Water and small air bubbles are fed into the column. Proteins and surfactants are adsorbed at the bubble-water interface. The foam rises to the top glass and is removed into the drain. Efficiency depends on bubble size, contact time and air to water ratio.

  • The recommended air:water benchmark is from ~1:4 to 1:8 (selected locally).
  • Control: foam level, turbidity/color, ORP before/after.
  • Maintain a stable fine bubble (injector, spray, needle rotor).
Driving Modes
  • Co-current: water and air go in the same direction. Compact, easier to strap.
  • Countercurrent: air from bottom to top, water from top to bottom - longer contact, higher foam extraction at the same column height.
  • For high flow rates - countercurrent or cascading of several columns.

Selection and integration into RAS

  • Position: after mechanical filtration (for example, drum) and before the biofilter.
  • Sizing: water consumption m³/h, required DOC reduction, column height, air:water, contact time.
  • Hydraulics: column resistance, maintenance bypass, foam discharge into the sewer.
  • Materials: salt water → PVC/stainless steel AISI316L, ozone resistant gaskets.

Options and integration

  • Ozonizer with Venturi injector, degassing and carbon column.
  • Backup pump, air reserve, vacuum sensor.
  • Remote monitoring, foam level/O₃ leak alarms.
  • Activated carbon cassette for gas outlet, washing injectors.

Frequently asked questions

Why is there not enough foam?

Large bubble, low DOC, little air or too high water velocity. Check air:water and injector/spray condition.

When is countercurrent needed?

At high flow rates and increased organic matter, it provides longer contact time at the same column height.