Industrial Reverse Osmosis - Designing Reverse Osmosis Equipment in Power Generation Facilities

In a power plant, industrial Reverse Osmosisof an industrial Reverse Osmosis equipment system:
equipment (RO) is used almost exclusively in theElement, Array (Train), Stage, and Pass.
boiler water pre-treatment area. Since most powerThe industrial Reverse Osmosis Element is the building
boilers tend to operate at elevated pressureblock of any RO equipment system. It is the individual
(>700 psig [4.8 MPa]), boiler feed water quality iscomponent, where the RO process occurs.
very stringent. As a result, industrial Reverse OsmosisThere are four main designs for the elements:
Equipment in this application is invariably followed by- Spiral Wound - Most common design for water
some type of demineralization (demin) polishingpurification
equipment, designed to reduce feed water dissolved- Hollow Fiber - Very large membrane surface areas
solids, especially silica, to very low levels. Industrialare possible in this design. Used in seawater
Reverse Osmosis equipment, by itself, is incapable ofdesalination
providing the boiler feed water quality demanded by- Large Tube - Similar to a shell-and tube heat
higher pressure power boilers.exchange in appearance and design. Used in special
Because the polishing demineralization equipment in awastewater treatment and food processing
power generation facility will be sized upon theapplications
expected industrial Reverse Osmosis equipment- Flat Plate - Similar to a plate-and frame heat
performance (permeate water quality and quantity),exchanger. Used in food processing applications
any problems with the Reverse Osmosis equipmentRegardless of the element design, high pressure and
operation can have drastic effects on the deminflow is needed to force pure water through the RO
performance. Poor demin performance can causemembrane to become permeate. Because of the high
costs to increase sharply, through increasedpressures needed, each element must be designed
regenerations and acid/caustic usage.so that the internal structures can withstand a
Further downstream, the impact of poor industrialfeedwater pressure of several hundred psig.
Reverse Osmosis equipment performance on theThe number of elements needed will be determined
power generation boilers can be severe, ultimatelyby the amount of the final product needed daily.
leading to plant de-rating, and even boiler and turbineThe industrial RO equipment Array is simply the way
damage.in which the elements are grouped together, in series
Understanding Reverse Osmosis Design for a Poweror parallel.
Generation Facility There are four main components