Large-diameter reverse osmosis product lowers cost and reduces footprint

Koch Membrane Systems Inc. (KMS; Wilmington, Mass.; www.kochmembrane.com) recently unveiled large-diameter reverse osmosis (RO) elements and pressure vessels for seawater desalination that offer cost savings and reduced footprints. The new RO element and pressure vessel combinations have an 18-in. dia. and a 60-in. length, rather than the standard 8-in.-dia., 40-in.-long size that has been commonly used. The larger size translates to an effective membrane area of 17,500 ft2 per vessel, compared to 2,800 ft2 for conventional 8-in. elements. “The larger diameter becomes cost-effective at capacities of around 1-million gal/d,” says Imran Jaferey, Koch’s vice-president for water and wastewater. “Once capacities get into the range of tens of millions of gallons per day, plants can realize cost savings of 30% and footprint reductions of 50%” with the larger-size product, Jaferey adds. The economics and smaller space requirements become increasingly important as seawater desalination plants seek more capacity and are located in more densely populated areas with limited land space. The product has installation advantages as well because it is available in pre-engineered packaged plants that require less fieldwork…