The US’ First Municipal Installation of a PX® Pressure Exchanger® for BWRO

Design experts from Kimley-Horn and Associates, Inc., a premier planning and design consulting firm, sought to reduce energy costs in anticipation of varying operating conditions by collaborating with Energy Recovery, Inc. to incorporate the PX® Pressure Exchanger®. The designers chose to integrate one low-pressure PX (LP PX) in two reverse osmosis (RO) skids to offset the rise in energy consumption brought on by the anticipated increase in water production and salinity.

The low-pressure PX offered a flexible solution for varying conditions, such as flow and pressure levels, capable of providing efficiencies of up to 98% despite changes in TDS and temperature. Typically installed at the brine stream of the final RO stage, the LP PX transfers hydraulic energy from the brine to the raw feedwater stream, reducing the work on the high-pressure pump and saving energy.

LP PX Integration Benefits

• Reduced the membrane feed pump flow by 20%.
• An estimated reduction in horsepower of at least 33 HP.
• Approximately $95,000 in reduced capital expenditure for the pump motor and other components.
• Stable efficiency maintained across variations in flow and pressure (5.5 – 27.6 bar; 80 – 400 psi).

LP PX MAINTAINS EFFICIENCY WITH VARYING FLOW AND PRESSURE LEVELS