D&S recently undertook a project to supply a 5m3/hr Dayliff Seawater Reverse Osmosis (SDRO) plant to the Faza island in Lamu. The RO plant will be used to treat seawater for use in by the Faza community.

The RO plant was designed at 50% recovery and used DOW filmtec SW30XHR-400i membranes to produce a permeate TDS of 71.19ppm from raw water TDS of 21,695ppm. 

The system was controlled from a single control panel that automatically controlled the operation of the plant, facilitating the filtration cycle that produced potable water, the feed and permeate flushing cycle which help clean the membranes and the plant pipework reducing corrosion probabilities. The system has provided for a Cleaning in Place (CIP) system fully integrated on skid for the RO CIP requirements. Danfoss APP7.2 and Danfoss APP5.1 do not have an integrated flushing path for performing CIP and Flushing operations when the pumps are not running and therefore a bypass was provided across the pumps to facilitate these cleaning operations 

Two Danfoss pumps i.e Danfoss APP7.2 and Danfoss APP5.1 were used in parallel to meet the duty of the plant. An absolute cartridge was also placed before each of the Danfoss High pressure pumps to prevent damaging of the pumps.