CCD-RO With Enhanced Recovery
Reverse Osmosis Closed Circuit Desalination with Enhanced Recovery
A ReFlex™ RO system combines media filtration with reverse osmosis to achieve recovery rates up to 95%. Like conventional RO, ReFlex™ RO uses crossflow but it uses internal circulation to provide higher better distributed crossflow which removes dissolved species from the membranes. Like media filtration the feed flow equals the permeate flow and the concentrate is purged periodically. ReFlex RO works in a batch wise fashion in two modes, closed circulation desalination and plug flow desalination. When in closed circuit desalination, the feed water flow equals the permeate flow. While brine is circulated in a closed loop to provide cross flow, dissolved salts accumulate in the system volume. As the salt concentration gradually increases, the pump pressure automatically increases to give a constant permeate flow. When the desired recovery rate is achieved a brine valve opens to release the concentrate and the fresh feed water pushes it out with plug flow while flushing the membrane surfaces. When the concentrate is fully rejected the brine valve closes and a new cycle begins again.
![Two-Bed Demineralizer](images/pix-ccd-ro1.1-revised.jpg)
Conventional RO typically achieves up to 75% recovery rates and requires 3-4 stages to get recovery rates higher than 85%. ReFlex™ RO systems achieve recovery by recirculation, not with multiple membrane elements and stages in series, and can therefore reach any desired recovery up to 95%. ReFlex™ RO uses shorter membrane arrays than those in conventional systems, eliminating low-flux tail elements, minimizing lead element flux, and accommodating a higher average flux.
Benefits:
- QUICK PAYBACK, GENERALLY BETWEEN 18 TO 36 MONTHS
- REDUCED MEMBRANE REPLACEMENT COSTS
- REFLEX™ RO TYPICALLY REQUIRES 20% FEWER MEMBRANES FOR A GIVEN FEED FLOW AND WATER CHEMISTRY THAN CONVENTIONAL RO
- UP TO 75% LESS BRINE WASTE
- REDUCED FEED WATER REQUIREMENT FOR A GIVEN PERMEATE FLOW, RESULTING IN REDUCED CAPITAL AND OPERATING EXPENDITURES FOR PRE-TREATMENT
- INCREASED UPTIME WITH LONGER RUNS BETWEEN MEMBRANE CLEANINGS, REDUCING OPERATING COSTS AND EXTENDS MEMBRANE LIFE
- DECREASED POWER CONSUMPTION BY UP TO 35%
- EXCELLENT TURN DOWN CAPABILITY OF UP TO 50%
Applications:
- Surface waters with variable turbidity
- Ground waters with high fouling tendencies