RK2 Freshwater Protein Fractionators

RK2 Freshwater Foam Fractionators

RK2 Freshwater Foam Fractionators are the original and still the most effective fractionator for protein and TSS removal in freshwater.

In freshwater the process of protein fractionation is used widely in the wastewater treatment industry (referred to as dissolved air flotation). Freshwater Foam Fractionators for Aquaculture applications have been pioneered and refined by RK2 with their development of the RK2 Freshwater Foam Fractionators. While the bubbles are larger in freshwater than in saltwater, RK2 have designed and refined their designs to achieve maximum effectiveness of protein fractionators in freshwater.

The addition of Ozone into a freshwater fractionator add a vector for ozone to be introduced as well as helping to stabilise the protein fractionator and oxidise and flocculate waste into particles that are more easily removed by the protein fractionation process.

Protein Fractionation filtration removes suspended particulates, dissolved organics, proteins and tints. At the same time, protein fractionation lowers bacteria and pathogen concentrations, while saturating the water with oxygen. Traditional water filtration systems, (i.e: pressurized sand filters, bead filters and cartridge filters), remove particulates but are ineffective against dissolved wastes and act as breeding grounds for bacteria and pathogens.

We have spent significant time developing and refining our protein fractionator designs to be able to offer you the most effective freshwater protein fractionator system available.

RK2 Freshwater Foam Fractionators

Water that is filtered through traditional filters is constantly sieved through the trapped wastes. Similar to that of a tea bag, this action leaches bacteria, dissolved organics and tints back into the water. The media in the filter functions as a bio-filter, promoting bacteria, which in turn strip out oxygen. Consequently, the discharge from these filters is generally enriched with bacteria and dissolved organics as well as having reduced oxygen concentration.

The fractionation filtration process is simple and highly effective. Air, (in some cases ozone as well), are injected into the bottom of the reaction chamber via an ozone resistant venturi injector. The water to be filtered is introduced at the top of the chamber and exits at the bottom. This creates a mass mixing effect, with the water traveling cross current to the air, which is essential for the effective formation of foam. The foam rises through the column and becomes more concentrated as it passes into the upper rise tube. The tube allows for the water to drain back into the tank via gravity, while the concentrated foam is ejected over the top of the riser tube and collected into a waste drain. The upper chamber is automatically washed down with rinse systems that keep the surfaces clean and prevent the foam from drying and inhibiting the ejection process.


The quality is in the details

  • Honeycomb style cone riser assembly specifically designed for freshwater fractionation.
  • Enhanced air injection for excellent protein and dissolved organic removal, also excellent oxygen saturation in freshwater.
  • All Non-corrosive materials and construction, 316 stainless steel hardware.
  • Battery powered LCD wash down timer for low manual labor cleaning * 120/240V 50/60Hz available.
  • All models ozone ready.
ModelFlow rateDiameterVenturi PumpHeightFootprintOperational WeightDry Weight
RK10AC-FW35-75 LPM25.4 CM1/2 HP PUMP
230 VAC, 1 PH
215.9 CM38.1 X 91.44 CM124.73 KG45.35 KG
RK25PE-FW75-150 LPM35.56 CM1/2 HP PUMP
230 VAC, 1 PH
215.9 CM61.0 X 76.2 CM199.58 KG46.26 KG
RK50PE-FW170-340 LPM50.8 CM1 HP PUMP
230VAC, 1 PH
251.5 CM61.0 X 106.7 CM76.27 KG99.79 KG
RK75PE-FW245-510 LPM60.96 CM1.5 HP PUMP
230 VAC, 1 PH
259.1 CM61.0 X 106.7 CM635.02 KG106.59 KG
RK75PE-HF-FW375-585LPM60.96 CM1.5 HP PUMP
230 VAC, 1 PH
259.1 CM61.0 X 106.7 CM635.02 KG108.86 KG
RK150PE-FW585-1,150 LPM91.44 CM1.5 HP PUMP
230 VAC, 1 PH
256.5 CM91.4 X 137.2 CM1351.70 KG165.56 KG
RK150PE-HF-FW870-1,300 LPM91.44 CM1.5 HP PUMP
230 VAC, 1 PH
256.5 CM91.4 X 137.2 CM1351.70 KG170.09 KG
RK300PE-FW1,040-2,060 LPM121.92 CM2 HP PUMP
230 VAC, 1 PH
279.4 CM121.9 X 167.6 CM2304.24 KG199.58 KG
RK300PE-HF-FW1,550-2,325 LPM121.92 CM2 HP PUMP
230 VAC, 1 PH
279.4 CM121.9 X 167.6 CM2304.24 KG206.38 KG
RK600PE-FW2,210-4,440 LPM152.4 CM(2) 2 HP PUMPS
230 VAC, 1 PH
365.8 CM152.4 X 198.1 CM4846.63 KG340.19 KG
RK600PE-HF-FW3,325-4,990 LPM152.4 CM(2) 2 HP PUMPS
230 VAC, 1 PH
3658.8 CM152.4 X 198.1 CM4891.99 KG408.23 KG
RK1000PE-FW4,345-8,695 LPM213.96 CM(4) 2 HP PUMPS
230 VAC, 1 PH
365.8 CM233.7 X 289.6 CM9241.94 KG453.59 KG
RK2000PE-FW5,800-11,605 LPM213.96 CM(4) 2 HP PUMPS
230 VAC, 1 PH
426.7 CM233.7 X 289.6 CM11,584.74 KG544.31 KG
* = HF models operate at higher flow rates and reduced contact times
**Pro Series Models are available at an additional cost. Pro Series includes – schedule 80 PVC plumbing, Asahi True Union Ball Valves, Electronic Wash Down Assemblies and bulkhead fittings