Danfoss introduces a new and improved iSave 21 ERD for smaller SWRO plants

More robust, with enhanced reliability, design flexibility, and high efficiency are just some of the features of the new iSave 21 Plus, a new generation of the popular iSave 21 ERD for smaller seawater reverse osmosis (SWRO) plants.

In response to the ever growing demand for energy savings in smaller SWRO plants, Danfoss has developed the next generation iSave 21 energy recovery device for onshore and offshore applications. The highly efficient iSave 21 Plus saves up to 60 per cent on the energy bill and is easily built into existing SWRO solutions to obtain the savings right away.

The new iSave 21 Plus ERD with integrated pressure exchanger, booster pump and motor in one compact unit ensures optimum efficiency and short payback time of plants ranging in size from 110 m³ to 350 m³.

“We are proud to introduce the new iSave 21 Plus in response to the growing demand for energy efficient SWRO,” Jesper Bentzen, Sales Director of Danfoss, said. “The pressure boost of the iSave 21 has been increased from 3 to 5 bar in the new version to ensure high reliability. Furthermore, the new iSave 21 Plus is highly efficient and runs with long service intervals.”

The small footprint of iSave 21 Plus makes it ideal for applications where space is limited. The new design of iSave 21 Plus allows both vertical and horizontal installation.  

iSave 21 Plus captures hydraulic energy from the high pressure reject stream of the SWRO process and transfers the energy back into the system, reducing the energy consumption by up to 60 per cent regardless of flow rate and size of the system.

Besides the substantial savings during operation, iSave 21 Plus cuts CAPEX by reducing the required pump size and the number of pipes and components.