Closed Circuit Reverse Osmosis (CCRO) Configuration
The CCRO configuration tab (See Figure 1) is the same as that for RO/NF/ROSC system design, in this section referred to as traditional RO to distinguish it from the closed circuit process. With CCRO, system design and configuration are greatly simplified as CCRO consists of a single stage. This leads to several deactivated inputs (such as stage back pressure and inter-stage boost). In addition, there is no concentrate recycle input as 100% of the brine is recirculated during closed circuit operation.
The basic approach to design CCRO systems is typically only three (3) steps, firstly (1) select the appropriate membrane. Then (2) adjust the number of pressure vessels until the desired flux rate is achieved (refer to Membrane System Design Guidelines for 8" FilmTec™ Elements). Lastly, (3) open the flow calculator and enter the pass average recovery. In most cases, the default inputs in the flow calculator are appropriate and no further adjustments are required. This allows the majority of CCRO systems to be designed in seconds, and that simplicity and performance is transferred to the field as easier, more reliable operation.