Membrane Life - GE Merlin Application Manual

MEMBRANE LIFE

MERLIN RECOVERY VS. EFFICIENCY
20
Rev C
The Merlin uses a new, patented, RO membrane technology, not an ultra
or nanofiltration membrane.
It is a standard thin film membrane (TFM) style that is not tolerant of
chlorine.
Maximizing Membrane Element Life
Pretreatment is the key to maximizing the Merlin membrane element life,
like all reverse osmosis membranes. To maximize element life, adhere to
the following inlet water conditions.
Chlorine at inlet to element — 0 ppm
Inlet hardness to system — less than 10 grain, 0 grain optimal
Inlet iron to system — less than .1 ppm, 0 ppm optimal
Inlet manganese — less than .05 ppm, 0 ppm optimal
Temperature — 40 to 100°F (4.4 to 37.8°C)
One performance measure for a home RO system is the recovery/
efficiency rate. This is a published amount of permeate water produced as
a product of total inlet water used. The higher the recovery of an RO
membrane system, the less waste water is sent to drain.
• Recovery is the measured permeate (product) water volume
produced as a percentage of inlet water consumed. This is
measured directly from the membrane element.
• Efficiency is the measured permeate (product) water volume
produced as a percentage of inlet water consumed.
Efficiency is measured taking into account the complete system. This
measurement includes the storage tank and any other pressure drop
in the system.
Efficiency is the real-world performance that the consumer will
experience. Therefore it is the best measurement of system performance.
The Problem With Systems That Have Storage Tanks
Traditional home RO systems that utilize a tank may be able to boast 18-
25% recovery, however, most operate at much lower efficiency.
As storage tank systems produce permeate water, the tank exerts
pressure drop on the membrane as the tank fills and tank pressure
increases. This pressure drop decreases the membrane elements recovery
significantly as the tank fills. In many cases, the system's efficiency will
drop as low as 5% when the tank is near full.
But,
MEMBRANE LIFE