Energy Recovery Devices Type iSave
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.
For the complete range of Danfoss iSave Devices go to our dedicated website: High Pressure Water Equipment - iSave Devices
|iSave 21||iSave 40|
|Code number||180F7000 (US 180F7010)||180F7001 (US 180F7011)180F7003|
|Energy Recovery Device||iSave 21||iSave 40|
|Rated flow||21 m3/hr||41.4 m3/hr *1|
|Geometric displacement||265.8 cm3/rpm(16.2 in3/rpm)||626 cm3/rpm(38.2 in3/rpm)|
|High-pressure inlet flow, maximum||21 m3/hr (92.4 gpm)||44 m3/hr (194 gpm)|
|Low-pressure inlet flow, maximum||33 m3/hr (145 gpm)||67 m3/hr (295 gpm)|
|High-pressure inlet pressure,maximum||83 bar (1200 psig)||83 bar (1200 psig)|
|High-pressure inlet pressure,minimum||10 bar (145 psig)||10 bar (145 psig)|
|High-pressure inlet pressure,intermittent, minimum *3||3 bar (43.5 psig) *2||3 bar (43.5 psig)|
|Low-pressure inlet pressure, maximum *3||10 bar (145 psig)||10 bar (145 psig)|
|Low-pressure outlet pressure,minimum||1 bar (14.5 psig)||1 bar (14.5 psig)|
|High-pressure outlet pressure,maximum||83 bar (1,200 psig)||83 bar (1,200 psig)|
|Filtration requirements (nominal) *4||3 ìm melt-blown||3 ìm melt-blown|
|Torque, maximum *5||36 Nm (26.5 lbf-ft)||119 Nm (87.8 lbf-ft)|
|Starting torque (slip/stick)||-||85 Nm (62.7 lbf)|
|Power req. at 60 bar, and booster pressure of 3 bar||5.5 kW (7.5 hp)||10 kW (15 hp)|
|Weight including electric motor||95 kg (209,5 lb)||254 kg (560 lb)|
|iSave 21||iSave 40|
|Peak eff. inc. high-pressure booster pump at 60 bar||93%||91%|
|Maximum pressure raise on iSave *7||3 bar (43.5 psig)||5 bar (72.5 psig)|
|Maximum low-pressure differential(LP In - LP Out) *7||0.9 bar (13 psi) at 21m3/hr(92.4 gpm)||1.2 bar (17.5 psi) at 40 m3/hr(176.1 gpm)|
|Maximum lubrication flow at 60 bar||0.42 m3/hr (1.8 gpm)||0.8 m3/hr (3.5 gpm)|
|Minimum speed||500 rpm||600 rpm|
|Maximum speed||1,500 rpm||1,200 rpm|
|Salinity increase at membrane at 40% recovery rate||2-3 %||2-3 %|
|Typical noise level *6||86 dB(A)||88 dB(A)|
|*1 Typical average flow at 60 bar|
|*2 Minimum inlet high pressure can be 1 bar, if speed of iSave is maximum 750 rpm|
|*3 Intermittent pressure is acceptable for less than 10 minutes within a period of 6 hours|
|*4 Please see section 7 of datasheet - Filtration|
|*5 Warning: A minimum of 10 seconds is required when ramping up the speed from zero to maximum. Otherwise, the torque will exceed the maximum limit and may be harmful to the isave.|
|*6 Noise level is depending on system design. The noise level can be obtained by “proper” design. Please contact M & M Controls.|
|*7 At speed above 50Hz and power supply lover than 400V the maximum pressure raise is 4 bar.|
|Description||iSave 21||iSave 40|
|Motor size kW/HP||5.5/7.5||11/15|
|Frame size||IEC 132S-4P||IEC 160L-6P|
|Speed at 50/60 Hz||1440/1728||970/1165|
|Rated current (A)||10.7||22|
|Insulation according to DIN-IEC 34||Class F||Class F|
|Ambient temperature 40oC, 1000m above sea level||Class B||Class B|
|Degrees of protection||IP55||IP55|
|Standard coating according to IEC 60721-2-1||Yes Yes||Yes|
|The iSave can also be delivered with a marine motor, an ATEX motor or any other special motor.|
|Please contact M & M Controls for further information.|