case study sea water desalination

8/8/2019 Case Study Sea Water Desalination

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Thermax Supplied Largest Sea-Water Desalination Plant to a leading chemical

manufacturer in the year 2005.

The details of the plant are as belowThe details of the plant are as belowThe details of the plant are as belowThe details of the plant are as below::::

The R.O.Plant Capacity - 150 cum/hr x 3 streams

The Clarification Plant capacity - 625 cum/hr x 2 streams

The Plant details are as follows:

RAW WATER CHARACTERISTICSRAW WATER CHARACTERISTICSRAW WATER CHARACTERISTICSRAW WATER CHARACTERISTICS

High TDS- 32,000 TO 35,000 PPM Low suspended solids, Up to 30 NTU High organic matter - 15-20ppm as COD Temperature variations (Raw water)

The plant as supplied grass root by Thermax Ltd. had a 150 m3/hr permeate

capacity.

Today after 3 to 4 subsequent expansions, the permeate capacity is 750 m3/hr.]

BASIC SCHEMEBASIC SCHEMEBASIC SCHEMEBASIC SCHEME

PrePrePrePre----TreatmentTreatmentTreatmentTreatment

Inlet works receiving sump - non-mechanical flash mixing - 1250 m3/hrRectangular.

Tube settling with external flocculation zone. Dosing - Ferric Chloride and Polyelectrolyte - SS 200. Outlet quality after settling Turbidity less than 10 NTU. All wetted parts of RCC - FRP coated. Then to Clarified Water Storage Tank. Pumping to Horizontal Pressure Sand Filters 4 nos 375 m3/hr each. Further on to Horizontal Dual Media Filters 4 nos 375 m3/hr each. Quality - Turbidity less than 5 NTU and SDI less than 5.


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PrePrePrePre----Treatment to primary ROTreatment to primary ROTreatment to primary ROTreatment to primary RO

Cartridge Filters (4 x 375 m3/hr) 5 micron Then booster pumps (3 x 375 m3/hr),

Turbo Charger (3 x 375 m3/hr), High Pressure Pump (3 x 375 m3/hr) to achieve 60

Kg/cm2.

Reverse OsmosisReverse OsmosisReverse OsmosisReverse Osmosis

Primary RO (3 x 150 m3/hr permeate) - Secondary RO feed pump (3 x 56 m3/hr)

Secondary RO Cartridge Filters (3 x 56 m3/hr, 5 microns) - Secondary RO (2 x 56 m3/hr

permeate) - Mixed Beds (3 x 50 m3/hr) Chlorinator (3 x 10 kg/hr) - to generate 150to generate 150to generate 150to generate 150

mmmm3333/hr water/hr water/hr water/hr water with 0.2 conductivity and 20 ppb silica for producing Soda Ash.

TTTTHERMAX QUALITYHERMAX QUALITYHERMAX QUALITYHERMAX QUALITY

Design Sea Water Salinity 40,000 ppm Design Suspended Solids 2000 ppm Turbidity at Tube Settler Outlet Less than 5 NTU Turbidity at Filter Outlet Less than 1 NTU SDI at Cartridge Filter Outlet Less than 2 Primary RO Recovery 40% Secondary RO Recovery 89% Primary RO permeate Less than 450 ppm TDS Secondary RO permeate Less than 250 TDS Energy Recovered in Turbo Charger 40% Mixed Bed Conductivity 0.2 useimens/cm Mixed Bed Silica 0.02 ppm

SalientSalientSalientSalient ffffeatureseatureseatureseatures of plantof plantof plantof plant

Flocculation and Tube Settling System to counter low weight Suspended solids-colloids, density and thermal currents. Flexibility in flocculation speed (G value) Maximum concrete construction to avoid corrosion Simplicity of operation, system redundancy


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PerformancePerformancePerformancePerformance

1. Very high dosing accuracy required to get consistent results (Less than 5 NTU) 2. Very Sensitive water (Difficult to treat and control) 3. Temperature variations after once through heat exchanger a New experience

case study sea water desalination

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