How It Works

The PX energy recovery device uses the principle of positive displacement and isobaric chambers to achieve extremely efficient transfer of energy from a high pressure waste stream, such as the brine stream from a reverse osmosis desalination unit, to a low-pressure incoming feed stream. Virtually no energy is lost in the transfer.

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The heart of the PX device is a ceramic rotor floating in an almost frictionless hydrodynamic bearing. Inside the rotor are channels in which the concentrate from the membranes and fresh salt water come into direct, momentary contact. The rotor is turned by the momentum of the water at a speed that adjusts to flow variations to provide nearly-constant high efficiency over a wide operating range.
 

There are no pistons between the concentrate and the fresh salt water, but the rotor and associated components keep high and low pressure separate, thereby sealing the high pressure portion of the SWRO process.