OPERATORS MANUAL
ORION II
Orion II 500-10000 Operators
Page 29 of 95
Manual Part no: DOMAON0100 Issue A
April 2008
5.4.3 Option 40 Single Pass Reverse Osmosis
A more detailed description of the RO process is included in the Appendix.
Reverse Osmosis purifies water by passing water through a semi permeable membrane to produce
purified water with the contaminants from the feed water being concentrated into a concentrate
stream which is part recycled and part directed to drain.
The RO unit will consist of one or more, high-pressure stainless steel vessels (RO40-01, etc) fitted
with hot water sanitisable RO elements.
Product water (permeate) from the RO module(s) is collected in a stainless steel manifold where a
sanitary sample valve (V45-01) allows for chemical and bacteriological samples to be taken for
analysis. A non-return valve (V45-02) prevents reverse flow into the RO permeate and provides
back-pressure protection to the RO elements. Permeate then passes through flow transducer
(FT45-01) and conductivity and temperature (AE45-01) are also monitored.
A CIP connection (CIP3) and isolation valve (V45-03) allows for chemical cleaning of the RO unit.
Permeate CIP solution is returned to the CIP connection (CIP1) on TK30-01.
Concentrate leaves the final RO module, passes a pressure sensor (PT40-01) and is then split into
two streams, one is directed to drain and the other recirculated to TK30-01. The flow volumes are
measured by FT40-01 and FT40-02 respectively and controlled by two modulating valves, V40-01 on
the drain line and V40-02 on the recycle line.
During normal operation flows through the RO section are automatically controlled by three set
points entered into the HMI
–
1. Concentrate to drain flow measured by FT40-01 and adjusted by V40-01.
2. Concentrate recycle flow to TK30-01 measured by FT40-02 and adjusted by V40-02.
3. Permeate flow measured by FT45-01 and adjusted by increasing or decreasing the pump speed.
The flow of concentrate to drain is usually set to give an overall system recovery of 69 to 85% during
production.
The flow of concentrate recycle is set to maintain optimum flows through the RO elements.
When the unit goes into standby, the flow of concentrate to drain is reduced to save water, providing
the water temperature is below 25
o
C. To compensate for this reduction, the flow of concentrate
recycle is increased to maintain optimum conditions in the elements.
During hot water sanitisation flows through the RO section are readjusted as follows
–
1. V40-01 is closed to prevent concentrate flow to drain.
2. V40-02 is readjusted to the set points required for HWS.
3. RO feed pressure is adjusted by increasing or decreasing the pump speed, 7bar <45
o
C, 2.2bar
>45
o
C.
