Facility
The Seawater cooling system in JUBAIL is a vital
utility service which provides uninterrupted
supply of seawater for non-contact process cooling
to the primary industries of JUBAIL Industrial
City.
The Seawater cooling facility consists of two
adjacently located pumping stations near the
seashore and a distribution canal connected
to the customers through arrays of underground
lateral pipes. Seawater pumped into the distribution
canal flows by gravity to the customers and
the return water flows by gravity back to the
sea.
Seawater drawn from the Arabian Gulf through
dredged intake channels passes through coarse
trash screens and fine trash screens at the
pump stations and is chlorinated before it is
pumped into the distribution canal.
The two pumping stations have fourteen pumps
installed in each. The total installed capacity
of the pumping stations is 346 cubic meters
per second (29.9million cubic meters per day).
Chlorination plants attached to the two pump
stations generate Sodium Hypochlorite which
is used for disinfecting the seawater pumped
into the canal by continuous dosing and shock
dosing in order to control marine fouling.
Seawater from the pump stations is conveyed
to the customers through the canal system which
is about twelve KM long, stretching east west
and north south within the Industrial City.
The canals are generally trapezoidal in cross
section, and divided into three compartments
by vertical concrete walls. The north and east
compartments are only for supply and the south
and west compartments are only for return flow.
The middle one is normally used as an additional
supply compartment but can be used for return
flow if required.
The on-shore canal has four sections (Canal
1, 2, 3S and 3N) interconnected by inverted
siphons. Seawater is supplied to the customers
and returned to the canals through underground
concrete/FRP lateral pipes emanating from dedicated
off take/return structures located along the
vertical dividing walls of the canal. Sluice
gates installed at these structures provide
the flexibility to connect the lateral pipes
to either of the adjacent compartments.
Return water is discharged to the harbor through
another set of inverted siphons, on-shore Discharge
Channels, the outfall and a dredged discharge
channel.
The seawater intake and discharge are separated
by the causeway to the Industrial port which
serves as a barrier between the two and eliminates
the possibility of recirculation.
The pumping stations and distribution facilities
are connected to the Central Control Room through
DCS and SCADA system.
The pumping stations and distribution system
are provided with Cathodic Protection to minimize
corrosion.
Power supply for the pumping stations is provided
by SEC through two sets of 115 KV feeder lines,
each capable of taking the full load. Two gas
turbine generators of 10MW each are available
as source of standby / emergency power.
The seawater cooling facility will be extended
to the new industrial city Jubail 2, by constructing
a pump station at the west end of Canal 2 and
through a network of pressurized pipes.