OPERATING MANUAL FOR SELECT EDI 60
L300180 Iss:A
45
12.3
Process
Refer to flow diagram on following page.
All external hydraulic and electrical connections are positioned at the rear
of the unit to protect them from accidental damage.
On entering the Select Analyst an internal feed water strainer removes any
large debris remaining in the feed water supply.
When operated, an inlet solenoid opens and allows water to pass through
the pre-treatment cartridge to remove chlorine from the water and then on
to the reverse osmosis boost pump.
The boost pump increases the feed water pressure to a level to enable the
reverse osmosis (RO) membranes to operate efficiently.
The Pre-filtered water enters the first reverse osmosis module. Purified
water passes through the membrane and is termed ‘permeate’ (85-95% of
salts removed). The water containing the rejected salts passes across the
membrane and out of the RO module to drain and is termed ‘concentrate’.
The concentrate is pumped at high velocity across the RO membrane to
lessen the risk of fouling or scaling.
The concentrate flow rate is controlled by a fixed orifice restrictor located in
the drain line. The permeate is further purified by the second reverse
osmosis membrane with the ‘concentrate’ returning to the pump inlet for
recirculation.
The second stage ‘permeate’ then flows through the degasser where
excess CO
2
is removed prior to polishing with the Electro deioniser (EDI).
An optional NCP media cartridge containing high grade mixed ion-
exchange resin performs a final polishing if fitted.
The deionised water then feeds directly into the integral 20 litre storage
tank. Water can be dispensed from this tank via the front mounted bib tap.
When the tank is full, the unit feeds a small amount of water back through
the EDI to ‘turn over’ the stored water to keep it fresh and to ‘refresh’ the
EDI Cell.
If the unit performs 3 ‘refresh’ cycles within 20 minutes, the unit will go into
standby mode to conserve power. Drawing water from the tank to the mid
position will awake the unit and place it back into ‘Processing’ mode.
