Ultraspin Technology installed an oily water separation system at the Rio Tinto Iron Ore facility in Marandoo.
Designed as an oily water treatment facility, the ES25 oily water separator from Ultraspin Technology was installed to replace an existing coalescing plate pack system that was unable to meet the required TPH discharge standards of 20 mg/L.
The Ultraspin oily water separation system is a skid-mounted system, comprising of an Ultraspin ES25 (25m³/h) oily water separation unit with a helical rotor pump and strainer assembly.
The Ultraspin ES25 oily water separation system was installed to separate oil, grease and solids from the Central Attenuation Sump (CAS) to remove dissolved hydrocarbons.
Fluid properties of the process effluent water that influence the performance of the Ultraspin separator include:
- Oil water density difference
- Oil droplet size
- Water temperature
- Water viscosity
Oily water effluent is drawn through a single floating skimmer from the Central Attenuation Sump. The Ultraspin oil skimmers are automatic self-adjusting, free-floating models.
The oily water flows from the skimmer to a debris strainer on the separator skid, where large debris and particles are removed to protect the equipment. Cleaning of the strainer is required when the delta pressure is greater than 50 kPa.
A progressive cavity pump provides the pressure to drive the fluid through the Ultraspin oily water separators. A pressure switch is provided to shutdown the Ultraspin feed pump if it detects abnormal pressure.
This feed pump pressure creates a strong vortex that develops a centrifugal force to separate the oil droplets from the water. The vortex also affects the oily wet solids. Separated oil and smaller oily wet solids will exit with the reject stream while the treated clean water goes on to the evaporation pond.
The separated oil (with some water) is sent to the wet oil and sludge collection tank for further processing wherein the concentrated oil rises to the top of the tank.
The oil-rich layer at the top of the tank can be drawn from the liquid surface and collected in the dry oil collection bulky cube. The remaining water is decanted from the bottom of the collection tank and returned to the start for reprocessing.