SAWACO Water Desalination

SAWACO adopted the Sea Water Reverse Osmosis (S.W.R.O.) technology to desalinate seawater in order to produce high quality of potable water suitable for drinking, as well as for residential, commercial, and industrial uses.

The design output of the plant is 10,400 m³ / day. There are four (4) skids or R.O. trains (2 X 2500, 2 X 1800) that are in operation for the last four and a half years (4½) producing consistent quality of potable water qualities requested by different customers. An additional feature is the ongoing construction of the (SAWACO Phase-III) with a capacity of 1,800 m³ / Day to cope up the increasing demand, ready for commissioning this coming month of April 2006.

For Specific application 2 X 500 M³/day backish RO are available to further treat potable water to produce hi-purity water fit for specific industrial applications.

·    Each RO skids of Phase-I has (42) Pressure Vessels, each is designed to hold six (6) 40” membrane elements while Phase-II
    has (25) Pressure Vessels and each is also designed to hold six (6) 40” membrane elements made by Hydranautics.

·   The pump chambers houses the three (3) Filter Feed Pumps and Backwash Pumps for Phase-I and another 3 sets of filter Feed
    pumps for Ph-2. The Raw Water Tanks (RWT) and Pumps chambers are designed to accommodate the future expansion of
    the desalination Phase-III.

· The sea water intake is located around the plant using the Beach Wells. Six (6) 25HP Beach Well pumps for Phase-I and five
    (5) 20HP Beach Well pumps for Phase-II.

· The feed water is drawn from the raw water tanks to feed the pumps. The FFP (Filter Feed Pumps) a total of six (6) FFP for
    Ph-1 & 2 pump the raw water through the main feed water header to each phase.

·   IN Ph-1, four (4) Vertical Multi Media Filters (MMF) containing sand and anthracite while Phase-II is using the four (4) Horizontal
    fiberglass sand filters to remove suspended solids from the feed water. Both of Phase-I & II have their own backwashing
    procedures to ensure the quality of the feed water prior major processing.

·   The remaining feed water is then split into two streams and reaches the second stage of filtration, two (2) cartridge filters
     each streams. These two (2) cartridge filters on each RO streams removes particles larger than 5 micron in size.

·    Chemical dosing of the feed water ensures that the Silt Density Index (SDI), pH and chlorine content of the feed water are
    controlled as necessary prior to reaching to permeators. SBS dosing is respectively used to carry this out.

· Each RO stream has a High Pressure Pumps (HPP) that boost the pressure of the feed water. A Turbo Charger (ERT)
     energy recovery device on each stream further boosts the pressure. After the turbo charger, the high pressure feed
     reaches the permeators or membranes. Within the permeators the high pressure forces water through the thin composite
     film membranes by reverse osmosis, permeate is produced. The salt is left behind in the brine.

·   The permeate flows into the flushing tank and thereafter to the water storage tanks in the plant area. Post Treatment of
     lime and chlorine ensure the product water quality.

·   The brine flows to the brine side of the Turbo charger and thereafter to the reject tank (adjacent to the pump chamber)
     from where it is pumped back to the sea (by gravity only)

·   Other systems in the plant are the flushing system, for flushing the membranes and the cleaning system, for cleaning and
     post treatment of the permeators.

·    Automatic control of the plant is by programmable logic controller (PLC) and by ESCADA system.