iSave® energy recovery devices for high-pressure membrane applications

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

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

iSave® selection tool

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.

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Product range and related products

iSave® ERDs

Discover the full range of iSave® ERDs for small and medium train sizes between 200-3,300 m3/d. Choose between three sizes or configure in parallel to scale up flexibly. Visit our Product store for more information and technical literature.

MPE 70 ERDs

With its integrated pressure exchanger and motor, the MPE 70 is an active ERD designed for medium and large desalination plants when configured in parallel. The active design reduces mixing, biofouling and rotor overspin. Learn more

APP high-pressure pumps

With market-leading energy efficiency and field-proven reliability, the APP range of compact positive displacement pumps spans 0.6-92 m3/h. All pumps can be configured in parallel for higher capacity and work seamlessly with Danfoss ERDs. Learn more

Case stories using iSave® ERDs

APP pumps with ceramic chosen for containerized solutions

When a Spanish engineering company needed one compact, reliable, and energy-efficient SWRO solution for three separate end users, Gefico’s engineers proposed a compact, modular train design that could be both containerized and built on skids. Danfoss’s ceramic APP pumps and iSave ERDs are at the heart of the seven trains that Gefico designed and produced.

WatMan specifies Danfoss for the world’s largest cruise ship’s SWRO plant

WatMan Engineering chose Danfoss high-pressure pumps and energy recovery devices as key components in the SWRO plant that supplies fresh water to the world’s largest cruise ship, Icon of the Seas. The Finnish water treatment specialist will also rely on Danfoss to keep the water flowing on the next two ships in the Icon class.

Peter Taboada tailors energy-efficient well-boat SWRO with flexible Danfoss technology

Peter Taboada works closely with wellboat builders to meet their water-making needs. The company focuses on reliable energy efficiency that makes optimal use of available space to maximize their customers’ ROI. Flexible Danfoss high-pressure pumps and ERDs are part of the company’s success.

Danfoss components chosen to provide fresh water in emergency situations

Metis Water chose Danfoss APP pumps and iSave® ERDs for its mobile 1,000 m3/d SWRO plant. Designed to fit inside a 40 ft container, the plug-and-play solution can quickly be deployed to supply fresh water in emergency situations – reliably and energy efficiently.

Danfoss supplies energy-efficient SWRO to a resort in the Maldives

Compact, reliable and energy efficient pumps and ERDs from Danfoss are chosen as key components for SWRO plant producing fresh water for a multi-island resort complex in the Maldives.

Reduced energy costs with Danfoss APP pumps and iSave® ERDs

A reduction of 57% on the energy consumption was achieved by retrofitting with Danfoss pump and iSave® ERD.

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.