Two thousand g, and a membrane that cleans itself
Gravity settling is slow because gravity is weak. Put the same separation in a rotating field and the driving force rises by an order of magnitude — while the rotation scours the membrane that does the fine cut.
How the field is made
Liquid enters the cone tangentially and spins. The resulting centrifugal field reaches roughly 2000 g at the wall. Heavy phase — water — is thrown outward; light phase — oil — migrates to the axis and forms a core that is drawn off separately. Solids that would settle in hours under gravity separate in seconds.
The same rotation passes across the membrane surface. Instead of a static cake building up, the tangential flow continuously scours it, so the membrane keeps working at high solids loading. This is the difference between a membrane system that is cleaned weekly and one that is cleaned monthly.
Where it earns its place
- Oilfield produced water. Free oil and dispersed oil removed ahead of SiC filtration to reach <10 mg/L for reinjection. Polymer-laden frac flowback needs adjusted pre-treatment — we will not quote a standard package for it.
- High-strength industrial wastewater. Where a conventional DAF would need a large basin and a lot of chemical, the rotating field does the coarse work in a fraction of the volume.
- Membrane pre-treatment. Reducing oil and solids before an RO or SiC stage is the cheapest flux improvement available.
Measured performance
| Parameter | Value | Basis |
|---|---|---|
| Separation field | ≈2000 g | Design value at the cone wall |
| Oil in water, outlet | <10 mg/L | Produced water, three-stage configuration |
| Inlet oil range | 200–2,000 mg/L | Documented project range |
| Capacity per skid | 5–200 m³/h | Parallel skids above that |
| Membrane | 20 nm SiC | Where fine filtration is combined in the same skid |
The honest trade-offs
What you are accepting
- Rotating equipment needs maintenance. Bearings and seals are wear items. A static DAF has no such schedule; this does.
- Feed solids have a ceiling. Beyond the design limit, the cone plugs and the advantage disappears. Pre-screening is not optional.
- It is a separation device, not a chemistry fix. Dissolved oil, dissolved organics and salinity pass through. If your consent limit is on dissolved parameters, this is not the answer.
Project references: produced-water reinjection (TDS 30,000–60,000 mg/L) and mine-water applications, with scheme numbers traceable to acceptance reports. No figure on this page is extrapolated from a different water.
Does your water have free oil above 200 mg/L?
Then this is worth a conversation. Below that, flotation alone is usually cheaper and simpler, and we will tell you so.
Send a water analysis → Compare with flotation