Working principle:

The feedwater flows through filters and an UV-disinfection system to the energy recovery system. The pump pressure of 20bar is transferred to ~ 56bar/seawater or ~28bar/brackish water and flows to the RO-membranes.

At the RO-membranes, feedwater separates into drinking water and brine. Drinking water leaves the system and the brine, still under pressure, flows back to the energy recovery system to support the process.

Flexible power supply
This seawater and brackish water desalination systems are based on the principle of reverse osmosis (RO). In this process pressurized seawater flows over a membrane. The structure of the membrane retains the dissolved salts ? water is able to permeate. The result is pure drinking water. The major innovation lies in the energy recovery system: After passing the membrane, a three-piston system recycles the energy of the remaining seawater pressure with virtually no loss.

Thus, desalination and energy recovery occur in a continuous complementary process, forming a cycle. This wind powered seawater desalination system has no fixed operating point. The water production can range between max. 12.5 % and 100% of the nominal capacity by adjusting the piston speed. This has two main advantages:

Firstly, operation is possible with a fluctuating energy supply, and secondly, output can be adjusted flexibly to water demand without shutting down the plant.

Only about 25 % of the energy in the reverse osmosis process is used to produce drinking water, so without a recovery method, about 75 % would go to waste.

The energy recovery system comprises a low-pressure pump (max. 20 bar) and a three-piston system, which raises the pressure up to 56 bar and simultaneously re-uses the remaining energy. There is no need for a high pressure pump and second booster pump.

So this system consumes very little power and works extremely energy efficient.