New System Lowers Costs of Seawater Desalination

KSB (Germany) are planning to launch their new compact unit for reverse osmosis with seawater desalination in early 2013.

Called the SALINO Pressure Center, the unit will consist of an axial piston pump and an axial piston motor, arranged on a common shaft. Driven by the diaphragm return flow, the axial piston motor transfers its power directly to the pump shaft. These means three functions will be fulfilled by one and the same unit: creating high pressure, compensating pressure losses and recovering energy. There is no need for a separate booster pump.

The entire system runs on a single electric motor and frequency inverter. Compared to conventional energy recovery systems with pressure exchangers or Pelton turbines, this design saves up to 50 % in energy costs.

The SALINO Pressure Center is designed for RO systems (reverse osmosis systems) with a capacity of up to 480 cubic metres per day. The electric drive has a rating of 29 kW. All components are resistant to seawater and dimensioned with low life cycle costs in mind. Fluctuating salt contents in the seawater to be processed can be responded to by means of the integrated control system.

In recent tests the new compact unit desalinated one cubic metre of seawater with a salt content of 35,000 ppm at a power input of approximately two kilowatts per hour. As no piping is required between the individual components, the new system takes up minimal space, which makes it ideal for use in mobile container units.

KSB is the first manufacturer to supply this type of compact system for the RO process. Field tests have been underway at various Middle Eastern sites since October 2012. RO systems have become well established in seawater desalination and will continue to grow in popularity. This purely mechanical desalination process works independently of any heat sources, unlike evaporation methods. The investment costs are considerably lower than those of thermal systems. Standardised system designs minimise installation times and enable straightforward operation and service.