Traditional produced water treatment is usually comprised of hydrocyclones followed by degassing or flotation processes. Increasingly stringent environmental discharge requirements plus the constant pressure to reduce equipment footprint have led to the development of the Compact Flotation Unit (CFU). Veolia has taken this process forward to the next level with the Cophase™ CFU.
Benefits / Key Features
Self regulating oil skimmer eliminates gas and reduces water in the reject stream
No motor or pump consuming power
No need for pressurised water or gas; in most cases no gas consumption at all
Skimmed flow minimised to <1% of total flow
One minute retention time reduces vessel size and weight
100% of the inlet flow passes through the LoHead™ eductors ensuring excellent gas/liquid contact and superior separation performance
Highly tolerant of typical FPSO motion
No rotating parts to maintain
Designed for high flow rate
The Cophase™ CFU LoHead™ eductor design is unique in that 100% of the inlet flow is fed through the gas eductors, thus maximising bubble generation and contact between the oil droplets and gas bubbles. By enhancing the opportunity for contact between the oil droplets and the gas bubbles, greater oil removal efficiency for a given vessel volume is achieved.
The LoHead™ eductor design also generates a vortex within the separation volume. This vortex applies centripetal force upon the heavier water and solids, forcing them to the periphery of the vessel and therefore concentrating the oil and gas bubbles in the centre and so aiding agglomeration and coalescence.
An important feature of the Cophase™ CFU is that this vortex, combined with the internal geometry of the vessel has been designed using Computational Flow Dynamics (CFD) to suppress backmixing in the vessel. This means that the water passes through the separation volume in what is termed "rotating plug flow", which leads to a higher oil removal efficiency than is achieved in the older designs of flotation units currently available.