total water mangment.pdf

8/10/2019 total water mangment.pdf

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TOTAL WATER MANAGEMENTSOLUTIONS

for

POWER INDUSTRY

by:Ion Exchange India Ltd.


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Critical Impurities in Water

Total Dissolved Solids

Dissolved Silica

Colloidal Silica

Total Organic Carbon / Organics


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Pretreatment of Water

Objective is to remove all undissolved impurities presentin water and minimise operational problems indownstream RO and DM plants.

Undissolved impurities present in surface waters areSuspended solids

Colloidal particles

Colloidal organic matter and

Colloidal silica Algae

Bacteria


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pH 6.8 - 7.2 Conductivity < 0.2 MS/cm Total iron Nil Total silica < 0.02 ppm Total hardness Nil

Quality of Treated Water Required forFeed to High Pressure Boilers


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Boiler Water TreatmentObjectives

To keep makeup, boiler and condensate waterparameters as per design guidelines

Minimising blow down

Prevention of scales and deposits

Minimising corrosion

Eliminating priming and foaming


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Treatment Processes

Softening

De-alkalization

De-mineralisation

Reverse Osmosis

Ultra filtration

Condensate Polishing Unit (CPU)


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Most Critical Impurities

Silica

- Reactive- Non-Reactive

Organic Matter


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Most Critical Impurities

Reactive silica can be removed in DM plant

Non-reactive or colloidal silica gets converted into

reactive silica at high pressure & temperature in

boiler drum & results into scale formation.

Similarly Organic matter on the other hand splitsinto humic & fulvic acid.


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Presence of Organic Matter

Mostly of vegetable & animal origin Consists of molecular weight of carboxylic acid often

termed as Humic & fulvic acid

Causes :

Often break-down in Boiler , depresses pH & causes

corrosion

It effects the performance of resins and output of DM

plant

Tends to alter the surface tension of the boiler & causesfoaming


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Presence of Organic Matter

Methods for removal of Organic Matter

Pre-chlorination oxidises dissolved organic matter

Organic matter in colloidal form is removed by proper

coagulation, flocculation & clarification ( HRSCC )

It can be effectively removed by Ion Exchange resins

( Organic Scavenger ) INDION 830

Ultrafiltration


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Technologies for removal of

Non-Reactive Silica Pre-treatment of water ( Coagulation & Clarification)

Ultralfitration


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Pre-treatment of Water

Optimum removal of non-reactive silica : Ensure effective pre-chlorination of water

Maintain optimal pH condition Dosing of primary coagulants like alum, polymers for

flocculation

High rate solids contact clarifier ensures adequate

contact with colloidal particles & coagulants

Note : Coagulation can remove almost 60-70% of non-

reactive silica


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Advantages of UF in

Boiler Pre-treatment Removes colloidal silicates, aluminum and organics( humic & fluvic acids)

Reduce silica deposition on turbine blades

Reduce corrosion potential of high molecular weight

organics Reduce turbine maintenance

Reduce boiler feed chemicals Fewer make-up water upsets more on-line time

Less power purchase from utilities


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What Can UF Remove ?SilicatesColloids

Particulate Matter AlgaeBacteriaColiformVirusesGiardiaCryptosporidiumOils and GreaseProteins

Ultra Filtration

What can UF Reduce ?Total Organic CarbonColor components

What UF Cannot remove ?Salts

GasolineSugarsAlcoholsLow MolecularWeight Molecules


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UF Performance Colloidal SilicaRemoval


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Prestigious Projects

Seven stream softening plant,

each 1000 m3/h

At thermal power station,

Maharashtra State ElectricityBoard, 2 X 500 MW, India

Control panel for semi-automaticoperation, one of the largest in India for a

water treatment plant

Four stream demineralisation plant, 125 m3/h each


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Water treatment plant, three

sub-systems, total capacity

2200 m3/h

Condensate polishing units

At thermal power station, Maharashtra

State Electricity Board, 2 X 500 MW,

India

Prestigious Projects


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Key - Issues1. Scarcity of water & environmental concerns

2. Recycling of water, scrapping out - once thru' systems inold plants

3. New advanced technologies, like WBA - WAC & HRSCCfor higher effectiveness

4. Openness for introduction of new technologies

5. UMPP's & focus on more projects in coastal areas6. Division of labour, specialization of skills and O & M for

WTP installations

7. CPU for even smaller capacity plants(250 Mw cap.) forbetter PLF

8. Fire Side Chemicals

9. Speeding up R & M of plants


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THANK YOUTHANK YOU

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