Seaclean™Filter

PROTECT THE CORE OF REVERSE

OSMOSIS MEMBRANES WITH MULTI-

MEDIA FILTRATION

DESALINATIONPRESSURIZED MULTI-MEDIA FILTRATION FOR

THE CLARIFICATION OF SEAWATER

P-PPT-D-003-EN-1004

DESSALEMENTDESALINATION

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CONTENTS

Seaclean™

Filter

� Seawater Pre-treatment Objectives

� Seaclean™ Filter Description

� Seaclean™ Filter in Treatment Lines

� Product Performances

� Advantages of Seaclean™ Filter

� Case Study: Al Dur, Bahrain

DESSALEMENTDESALINATION

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PRE-TREATEMENT OBJECTIVES

To maximize the efficiency and lifespan of a desalination plant using reverse osmosis, pretreatment aims to prevent clogging of osmosis membranes by:

• removing algae/suspended solids/colloids,

• obtaining a low clog power of water.

Seaclean™

Filter

DESSALEMENTDESALINATION

4

Seaclean™ Filter DESCRIPTION (1/2)

• Seaclean™ Filter is a pressurized horizontal filter that applies a downflow through 2 layers of media: − A top layer of anthracite

– A bottom layer of sand

• The characteristics of Seaclean™ Filter:

– Diameter 4m

– Length 12,5 or 16 m

– Nominal surface area: 51 m² or 63m²

• Backwash is divided in 2 phases:– One air phase

– One water phase

ANTHRACITE

SAND

Seaclean™

Filter

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• The innovation consists in applying the new Anthracite / Sand

pair while the pressurized twin-layer technique remains

unchanged.

• The first layer is used to screen out suspended solids.

• The second layer is used to reduce the SDI (Silt Density Index)

• There are 2 possible media combinations: – Type A combination: Anthracite = 1.5mm / Sand = 0.28mm– Type B combination: Anthracite = 1.2mm / Sand = 0.28mm

Seaclean™ Filter DESCRIPTION (2/2)

Seaclean™

Filter

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Seaclean™ Filter IN TREATMENT LINES

Seaclean™ Filter forms part of Reverse Osmosis pre-treatment in seawater desalination line.

• Downstream from a flash flotation tank (Seadaf™) on water that has occasional organic matter and algae bloom peaks:

• In direct filtration application for treating turbidity:

Coagulant

H2SO4

Coag. aid

Seadaf™Seaclean™

RO

Coagulant

H2SO4

Coagulant

H2SO4

Coag. aid

Seaclean™

RO

Seaclean™

Filter

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Seaclean™ PERFORMANCE (1/2)

FILTRATION VELOCITY ON DUAL MEDIA FILTER

* Velocity n : nominal velocity range with all the filters in operation

• FILTRATION VELOCITIES:

− Depending on the quality and temperature of the water

− Depending on whether or not the clarification stage is

included (flotation or sedimentation)

Seaclean™

Filter

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• BACKWASH VELOCITIES:

(NES = Nominal Effective Size in mm)

Backwash velocity during water alone phase at 20°C for media combinations.

Seaclean™ PERFORMANCE (2/2)

Seaclean™

Filter

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Seaclean™ Filter ADVANTAGES

• FILTERED WATER OF A STABLE QUALITY:

– Good layer re-grading after washing– Regular cycle times

• MINIMIZED DANGER OF MEDIA LOSS:

– Thanks to the optimized process (filtration / backwash rate)

• WASH EQUIPMENT REDUCED TO A MINIMUM

• EFFICIENT REVERSE OSMOSIS PRE-TREATMENT

Seaclean™

Filter

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CONTEXT: • Client: Hyundai Heavy Industries (GDF Suez

Energy Int. / Gulf Investment Corporation 50/50 consortium)

• Contract: BOO – Commissioning: 2011• Electricity generating and seawater

desalination plant

DESIGN:• Drinking water production capacity:

218,000 m3/jour • Treatment line: − Pumping− 14 Seadaf™ flotation units− 44 Seaclean™units− 26 reverse osmosis racks, 1st pass− Energy recovery (Pelton Turbine)− 12 reverse osmosis racks, 2nd pass

CASE STUDY: AL DUR, BAHRAIN