There are a number of energy recovery devices in the market today, and although no design is perfect, here are a couple of reasons why the PX Pressure Exchanger® is the best energy recovery device available today:

Single Moving Part: The rotor is the only moving part in the PX device. It turns automatically, driven by flow and riding on a nearly frictionless hydrodynamic bearing. The elegant design and superior materials employed in the PX device assembly require no scheduled maintenance.

Ceramic Components: At the core of the PX device is a cartridge made of tough, engineered Corundum (aluminum oxide) ceramic. This material is unaffected by chemicals and will not corrode. Its properties are similar to that of sapphire and its hardness exceeds that of many stainless steels by a factor of three. In fact, most PX devices taken apart for inspection after years of service, exhibit no wear or deterioration in performance whatsoever. Engineered, highly impact-resistant aluminum oxide ceramic is ideal for SWRO applications because it is extremely durable, never corrodes and maintains exceptional dimensional stability.

Highest Possible Efficiency: The PX device's rotary mechanism recovers energy from the high-pressure waste stream of reverse osmosis systems at up to 98% efficiency. It utilizes a positive displacement mechanism and operates at nearly constant efficiency. This characteristic differs from centrifugal devices whose performance declines as flows and pressures shift away from best efficiency points.

Ease of Operation: No pistons, valves, timers, artificial intelligence or adaptive control schemes are required with PX technology - just simple flow controls. When the rotor is not turning, flow passes directly through the PX device. This design makes startup and shutdown easy. Because of proven reliability and maintenance free performance, the ERI PX is one of the few rotating devices in the world that is backed by a free five year warranty.

Flexible Arrays: By arraying multiple PX units, there is no limitation to the train size possible with PX technology. Up to 40 PX devices have been successfully arrayed in a single train and 10 to 16 rotors in parallel are common. If one or more rotors in an array stop turning, flow safely passes through the stuck rotor allowing a plant operator to wait for a convenient time to service the unit. PX units in an array can be easily and quickly removed or added, providing flexible capacity.

Reliability and Redundancy: Due to the modular design of the PX device, units can be added or removed for almost unlimited expansion or reduction in production capacity and recovery rate. In addition, with a conservative design, a plant with multiple PX devices in arrays of five or more can typically operate indefinitely with one or more PX devices removed from service providing for maximum on-line time.

Cost of Ownership: Designed for 100% online time with no scheduled maintenance, easy operation and ceramic parts that will never corrode. The ERI PX device provides the lowest possible cost of ownership.

Smallest Footprint: ERI's PX technology occupies as little as 1/10th the plant footprint and can weigh less than 1/8th of any other of the slow-cycle, clunky isobaric technology on the market.

Manufacturing Quality: Because of the harsh conditions and continuous service requirements in SWRO plants, material specification, fabrication and assembly are critical to ensuring ERI's products perform consistently and reliably. Precise machining, inspection and performance testing are conducted. ERI's Engineering and Manufacturing departments work closely to maintain tight control and assure quality. The results speak for themselves: hundreds of PX units deployed around the world provide years of continuous, reliable service with no periodic maintenance.