iSave energy recovery devices for high-pressure membrane applications

  • Overview
  • Selection tool
  • Product range and related products
  • Case stories using iSave ERDs

Energy recovery made simple

The iSave’s unique design integrates an isobaric pressure exchanger with a booster pump and motor.

  • Extremely compact: Ideal for limited spaces
  • Unsurpassed energy efficiency: Up to 94%
  • Field-proven reliability: Long service intervals and sturdy performance
  • Simple installation: Less piping, welding, and pressure losses
  • Active control: Minimize overspin and biofouling, and ready for smart automation

High-pressure membrane system designers and operators worldwide depend on iSave energy recovery devices to save energy and maintenance in containerized, marine, and land-based SWRO plants as well as in land-based wastewater/water reuse plants.

Optimized for reverse osmosis trains between approximately 200-3000 m3/day, iSaves are available in four different sizes, from 21-70 m3/hour, for either horizontal or vertical installation.

3-in-1 design saves space, energy, and maintenance

The iSave’s innovative design puts three key components where they belong: right next to each other. This integrated design not only saves space and piping. It also enables active control to adapt to seasonal variations with maximum efficiency and reduced mixing.  The motor control eliminates the risk of rotor overspin and rotor stops due to biofouling and facilitate smarter automation and predictive maintenance. 

Isobaric pressure exchanger

With best-in-class net efficiency rates, iSaves transfer the brine’s hydraulic energy directly to the feed with minimal mixing and leakage. High grade duplex and super-duplex materials ensure long-term reliability and durability even in aggressive fluids.

Positive displacement booster pump

The high-efficiency booster pump requires minimal energy to precisely control the high-pressure flow to the pressure exchanger, eliminating the need for a high-pressure flow meter. Positive displacement pump technology ensures high efficiency under any operating conditions.

Motor

With a fixed bellhousing ensuring perfect alignment between pump and motor ­– and no belt drives to maintain – installation, maintenance, and servicing are simple and easy.

Selection tool

iSave selection tool - Danfoss

iSave selection tool

Download the iSave selection tool for easy calculation and selection. Calculate amount and size of iSaves for your project.

Discover more about iSave 21 Plus

The Danfoss iSave 21 Plus ERD is transforming small-scale SWRO and ZLD plants. It brings big financial and GHG savings to train sizes between 200-680 m3/d.

Product range and related products

Case stories using iSave ERDs

Energy recovery devices are critical to decarbonization

As communities around the world expands their use of high-pressure membrane processes for SWRO and wastewater treatment, they also increase their energy consumption. Energy recovery devices are an essential way to make these applications more energy efficient and reduce related greenhouse gas emissions.