OPERATORS MANUAL
ORION II
Orion II 500-10000 Operators
Page 25 of 95
Manual Part no: DOMAON0100 Issue A
April 2008
temperatures from being exceeded.
5.1.5 Option 11 Hot Water Sanitisable Softeners and Filters
This pre-treatment option softens and filters the water prior to the RO section to prevent scaling or
fouling of the RO membranes. The Carbosoft option removes chlorine in addition to the above to
prevent oxidative damage of the RO membranes and CEDI if chosen.
The softeners and associated equipment are manufactured in stainless steel to allow for hot water
sanitisation (HWS).
As water enters
the system it “tees” off to an automatic valve VA11-01 fitted with a limit to open
device (set up on commissioning). VA11-01 is open during Cooling Stage 1 following hot water
sanitisation (HWS) to cool the hot water as it flows to drain. This prevents drain water maximum
temperatures from being exceeded.
Water then passes an inlet sample valve (V11-01 through a water flow rate transmitter (FT11-01) a
non return valve V11-02, an automatic isolating valve (VA11-01) and a pressure indicator (PI11-01).
The main stream of water is now joined by a recycled flow of soft water from TK30-01 via NRV V11-
10.
The softeners remove the total hardness from the feed water by exchanging Calcium and
Magnesium (Hardness Ions) in the feed water, with Sodium ions held on beads of ion exchange
resin contained within the softener vessels.
When all of the sodium ions in the resin bed have been exchanged the resin is exhausted and
cannot remove any further hardness from the feed water. It then requires regeneration by passing a
concentrated common salt (Sodium Chloride) solution through it to displace the hardness ions with
Sodium ions before it can remove further hardness from the water.
Salt solution (brine) is produced by dissolving high quality tablet salt in a pair of salt saturator (TK17-
01 & TK17-02), which should be located adjacent to the Orion skid. Tablet salt is added manually to
the saturators and the dilution process is controlled automatically by the PLC and softener control
valves. Each tank is fitted with a low level switch (LS17-01 & LS17-02) which raises an alarm (after
an adjustable time period) in the event that the tablet salt level is low, but does not stop any
operating processes.
In normal operation the feed water passes through both softeners in series which provides a high
degree of softening of the feed water. Both softeners are, however sized to be individually capable
of taking the full service flow rate so that one unit can be taken out of production for regeneration
whilst the other unit provides soft water.
The softeners are fitted with automatic multiport valves, (VA11-03 and VA11-04) which perform the
regeneration sequences as well as allowing bypass during regeneration. This enables one unit to
remain operating whilst the other is being regenerated.
Each softener has a finite volumetric operating capacity that is dependent on the concentration of
hardness salts in the feed water.
Each Softener is fitted with a hardness detector (AS11-01 & AS 11-02) which senses when the
softener requires regeneration.
