Energy Recovery Device Type iSave 40

Danfoss has introduced two reverse osmosis energy recovery devices.

The iSave 21 with a brine flow of 7-21 m3/h and the iSave 40 with a brine flow of 22-40 m3/h are available now. More sizes are under development.

The Danfoss iSave consists of an isobaric pressure exchanger (PE), a high pressure positive displacement booster pump (BP) and an electric motor.
The isobaric pressure exchangers are based on the technology used in the Danfoss APP pumps, and the high-pressure booster pumps are based on the vane pump principle enabling a very light and compact design. The design of iSave 21-40 ensures lubrication of the moving parts by the fluid itself.
All parts included in the iSave 21-40 are designed to provide long service life with a constant high efficiency and minimum service required.
The vane pumps are fixed displacement pumps in which the flow is proportional to the number of revolutions of the driving shaft – enabling flow control.
The electric motor provides speed control of both the pressure exchanger and the high pressure booster pump on the same shaft – preventing over spin / over flushing.
The iSaves need a VFD that allows the motor to apply a constant torque from low speed to maximum speed.

Danfoss iSave 40