Abstract
The purpose of this project was to develop a compact, solar powered desalination unit that would not only provide fresh drinking water for remote communities, but do so with little attention or maintenance. It follows from Project E202 in which a pre-production prototype unit was constructed.
The Project team recognised that although Reverse Osmosis is the leading technology in the World for brackish water desalination, it is prone to fouling and failures of the technology are common. The development methodology has been driven by the need to reduce the risks of fouling. Accordingly, low recovery ratios are used at reasonably low pressures. The energy recovery system not only makes the low recovery ratio regime economic in terms of energy use, but also facilitates fully automatic start-up and shut-down as well as self-regulation during fluctuating insolation levels.
The production units that have been produced differ from the preproduction unit of Project E202, in that a single cylinder system has been adopted and the valving has been incorporated into the piston head and so is completely internal. While the single cylinder arrangement reduces the efficiency of the unit, it dramatically simplifies construction and reduces cost, while the internal valving has all but eliminated the valving slip that plagued Project E202.
Three units were produced with recovery ratios 25%. The preferred model, the 16% recovery produces 620mL per minute of fresh water from sunny winter conditions in Perth.