advance scale control technology for cooling water … f/advance scale control...

1 /GE /

Advance Scale Control

Technology For

Cooling Water

Systems

2 /GE /

Agenda

• Cooling Systems Problems

• Scale

• Scale Inhibition & Control

• GE New Stress Tolerant Polymer

• Case History

3 /GE /

Cooling Systems Problems

Microbio

Scale

4 /GE /

Scale

5 /GE /

Scale formation

Dissolved Atoms

Nucleation formation

Crystal Growth

Scale Formation

6 /GE /

Common Scale Minerals

• Calcium Phosphate

• Calcium Carbonate

• Iron Phosphate

• Iron Oxides

• Silicate.

7 /GE /

Factors Affecting Scale formation

• Water composition

• pH

• Temperature

• Water velocity

• System metallurgy

8 /GE /

Water Composition

9 /GE /

pH

10 /GE /

Temperature

11 /GE /

Water Velocity

12 /GE /

System Metallurgy

http://images.google.com.sa/imgres?imgurl=http://images.iop.org/objects/optics/news/12/8/9/AFM.jpg&imgrefurl=http://optics.org/cws/article/research/25570/1/AFM&usg=__US6_yNxM5hB_LmykRQFYzq-JIUI=&h=1113&w=400&sz=139&hl=ar&start=24&sig2=5My_1Ip9KDzdu-yvTU1-kA&um=1&tbnid=DE9prnV7TWhc8M:&tbnh=150&tbnw=54&ei=kzapSYrJBdzF-QaBjvGvAg&prev=/images%3Fq%3DSurface%2Broughness%26start%3D18%26ndsp%3D18%26um%3D1%26hl%3Dar%26sa%3DN

13 /GE /

Scale Inhibition & Control

• Change in Operation

parameters such as water

chemistry.

• Mechanical Methods.

• Change in system

metallurgy.

• Use chemical Inhibitors.

14 /GE /

Chemical Inhibitor Mechanism

• Threshold inhibition

• Crystal Modification

• Sequestration.

• Dispersion.

15 /GE /

Polymeric Scale Dispersant

• PAA (Polyacrylic Acid)

• PMA (Polymaleic anhydride)

• AEC ( Alkyl Epoxy Carboxylate)

• TMPS (Terpolymer)

• HPS ( Hydroxy Propyle Ether

Sulfonate Copolymer)

• ACM (Acrylamid Copolymer)

16 /GE /

GE New Stress

Tolerant

Polymer - STP

17 /GE /

Stress Tolerant Polymer (STP) -Overview

• Superior Performance

– Under Neutral pH Conditions

– Under Alkaline pH Conditions

• Chlorine Stable

• High Performance at the presence of Fe and Al

• Testable

– Off-line

– On-line

18 /GE /

New Stress Tolerant Polymer (STP)STP Performance vs. SAA

0 0.5 1 1.5 2 2.5 3 3.5

Far

Superior1High pH Excursion 1Presence of Aluminum1Presence of Iron

Superior 1Calcium o-PO4 Inhibition 1Zinc PO4 Inhibition1Calcium pyro-PO4 Inhibition

Improved 1Suspended Solids

19 /GE /

0

10

20

30

40

50

60

70

80

90

100

% P

O4 In

hib

itio

n

5 ppm 10 ppm

Polymer Dosage (ppm)

Terpolymer C Terpolymer B Terpolymer A AA/AMPS SAA STP

Calcium Phosphate Inhibition Static Bottle Test

Water Conditions: 400 ppm Ca, 100 ppm Mg, pH 8.2, 10 ppm PO4, 160°F (70°C), 18 hrs

Lab Data

20 /GE /

Zinc Phosphate Inhibition

Static Bottle Test

Water Conditions: 300 ppm Ca, 10 ppm PO4, 5 ppm Zn,

pH 8.0, 120°F (50°C ), 18 hrs

0

10

20

30

40

50

60

70

80

90

100

% Z

n Inhib

itio

n

5 ppm 7.5 ppm


Zn Inhibition (pH 8.0)

Tagged Polymer AA/AMPS SAA STP

0

10

20

30

40

50

60

70

80

90

100

% P

O4 In

hib

itio

n

5 ppm 7.5 ppm


PO4 Inhibition (pH 8.0)


21 /GE /

Zinc Phosphate Inhibition

Static Bottle Test

Water Conditions: 300 ppm Ca, 10 ppm PO4, 5 ppm Zn,

pH 8.5, 120°F (50°C ), 18 hrs

0

10

20

30

40

50

60

70

80

90

100

% Z

n Inh

ibitio

n

5 ppm 7.5 ppm


Zn Inhibition (pH 8.5)


0

10

20

30

40

50

60

70

80

90

100

% P

O4 In

hib

itio

n

5 ppm 7.5 ppm


PO4 Inhibition (pH 8.5)


22 /GE /

Dynamic Dispersion Tester

Sump

Pump

Flow Meter

Turbidity

Meter

pH

Meter

Data

Acquisition

D

i

s

p

e

r

s

i

o

n

C

o

l

u

m

n

23 /GE /

Dynamic Iron Oxide Dispersion TestWater Conditions: 500 ppm Ca, 200 ppm Mg, pH 7.5

750 ppm Fe2O3

Fe2O3 dispersion test (Timing from polymer addition)

0

500

1000

1500

2000

2500

3000

3500

0 200 400 600 800 1000 1200 1400

Time elapsed (min)

NT

U

5 ppm STP

2 ppm STP

5 ppm SAA

Control

NTU > 2000

was over

scale

Lab Data

24 /GE /

Bench Top Recirculating Unit - BTU

25 /GE /

Bench Top Recirculating Unit - BTU

26 /GE /

Iron Testing

Neutral pH Program: Stabilized Phosphate

Water Conditions: 3 ppm iron, 600 ppm Ca, 300 ppm Mg, pH 7.2 15 ppm o-PO4, 3 ppm pyro-PO4, 1.2 HRA

135°F (57°C) Surface Temp, 120°F (49°C) Bulk Temp

Same Polymer Dosage (7 ppm)

SAA

STP

Lab Data

STP

LCS 0.2 mpy

ADM 0.0 mpy

SAA

LCS 2.4 mpy

ADM 0.5 mpy

27 /GE /

Polymer Dosage as Function of pH

Test pH Surface

Temp., OF

Polymer Polymer

Dosage,

ppm

Turbidity,

NTU

Delta

ppm PO4

1 7.2 130 SAA 4 0.32 0.1

2 7.2 130 STP 2 0.35 0.1

3 7.4 130 SAA 8 0.3 0.3

4 7.4 130 STP 4 0.3 0.4

5 7.6 130 SAA 13 0.5 0.5

6 7.6 130 STP 8 0.5 0.5

7 7.8 130 SAA 18 0.7 0.6

8 7.8 130 STP 12 0.9 0.2 Surface free of deposits

Surface free of deposits







Heat Exchanger Tube

Appearance

Treatment Program: Stabilized Phosphate

Standard Water Conditions: 600 ppm Ca, 300 ppm Mg, 15 ppm o-PO4, 3 ppm pyro-PO4, 1.2 ppm HRA, 120°F (49°C) Bulk

Temp

7.2

7.4 STP

STP

7.6 STP

7.8 STP

2

4

8

12

28 /GE /

4 ppm STP

8 ppm SAA

Neutral pH Program

Standard Water Conditions: 600 ppm Ca, pH 7.9, 15 ppm o-PO4, 3 ppm

pyro-PO4

135°F (57°C) Surface Temp

Lab Data

High pH Excursion

29 /GE /

Effect of pH Excursion on Calcium Phosphate Control

pH 7.2

0

2

4

6

8

10

12

14

16

18

6/15 6/19 6/23 6/27 7/1 7/5 7/9 7/13 7/17

Time (Date)

pp

m

pH 7.4pH 7.6

pH 7.9pH 7.4

Soluble PO4

Available Polymer

pH 7.2pH 7.2pH 7.2

0

2

4

6

8

10

12

14

16

18

6/15 6/19 6/23 6/27 7/1 7/5 7/9 7/13 7/17

Time (Date)

pp

m

pH 7.4pH 7.6

pH 7.9pH 7.4

Soluble PO4

Available Polymer

pH 7.2pH 7.2

4 ppm STP – Standard

Conditions

0

2

4

6

8

10

12

14

16

18

5/30 6/3 6/7 6/11 6/15 6/19 6/23 6/27 7/1

Time (Date)

pp

m

pH 7.2pH 7.4

pH 7.9pH 7.4

pH 7.2

(8 ppm SAA Added)

Available Polymer

Soluble PO4

0

2

4

6

8

10

12

14

16

18

5/30 6/3 6/7 6/11 6/15 6/19 6/23 6/27 7/1

Time (Date)

pp

m

pH 7.2pH 7.4

pH 7.9pH 7.4

pH 7.2

(8 ppm SAA Added)

Available Polymer

Soluble PO4

8 ppm SAA – Standard

Conditions

Neutral pH Program

Standard Water Conditions: 600 ppm Ca, 300 ppm Mg, pH 7.2 - 7.9, 15 ppm o-PO4, 3 ppm pyro-PO4 ,

135°F (57°C) Surface Temp, 120°F (49°C) Bulk Temp

30 /GE /

Aluminum Testing

Neutral pH Program: Stabilized Phosphate

Water Conditions: 2 ppm Aluminum, 600 ppm Ca, pH 7.2, 15 ppm o-PO4, 3 ppm pyro-PO4, 135°F (57°C) Surface Temperature

Lab Data

Same Polymer Dosage (5 ppm)

STP - Surface free of Deposits

SAA - Moderate AlPO4 Deposit

31 /GE /

200 ppm Clay Test

Alkaline pH Program

Water Conditions: 400 ppm Ca, pH 8.6, 4 ppm o-PO4, 3 ppm Penta

Lab Data

13 ppm STP 15 ppm SAA

32 /GE /

Polymer Dosage as Function of Temperature

Test pH Surface

Temp., oF

Polymer Polymer

Dosage, ppm

Turbidity,

NTU

Delta ppm

PO4

1 7.2 130 SAA 4 0.32 0.1

2 7.2 130 STP 2 0.35 0.1

3 7.2 140 SAA 6 0.5 0.2

4 7.2 140 STP 3 0.1 0.1

5 7.2 160 SAA 8 0.2 0.1

6 7.2 160 STP 4 0.4 0.4

Uniform Ca-PO4 deposit






Heat Exchanger Tube

Appearance


Standard Water Conditions: 600 ppm Ca, 300 ppm Mg, pH 7.2 15 ppm o-PO4, 3 ppm pyro-PO4, 1.2

ppm HRA 120°F (49°C) Bulk Temp


33 /GE /


Standard Water Conditions: 600 ppm Ca, pH 7.2, 15 ppm o-PO4, 3 ppm pyro-PO4,

160°F (70°C) Surface Temperature4 ppm STP - Surface free of Deposits

8 ppm SAA - Uniform CaPO4 Deposit

High Temperature

34 /GE /

STP Polymer

STP Testing & Monitoring

• OFF-LINE Testing – Bench testing with spectrophotometer

using new reagent chemistry

– Measures polymer concentration directly

– Easier than the Mo test!!

• TrueSense ON-LINE Monitoring

– Continuous monitoring of polymer concentration in the cooling system

35 /GE /

TrueSense Online Dynamic Laboratory Study Without Polymer Control

Neutral pH Program Standard Water Conditions

pH: 7.2

Calcium: 600 ppm as CaCO3

Orthophosphate: 15 ppm

Pyrophosphate: 3 ppm

Skin Temperature: 135°F (57°C)

Retention Time: 3 days

36 /GE /

TrueSense Online Dynamic Laboratory Study With Polymer Control (continued)

Neutral pH ProgramStandard Water Conditions

pH: 7.2

Calcium: 600 ppm as CaCO3

Orthophosphate: 15 ppm

Pyrophosphate: 3 ppm

Skin Temperature: 135°F (57°C)

Retention Time: 3 days

37 /GE /

Case HistoryEuropean plastics producer saves US$135,000 year with STP TechnologyGoal

• Reduce phosphate discharge – new regulations made it

desirable to reduce the phosphate discharge from the

cooling water program

• Reduce acid consumption – with acid prices

skyrocketing, any acid feed reduction meant significant

savings

• Reduce water consumption

Solution

• Upgrade toSTP and revise the chemistry targets

Original Targets

GenGard Targets

Orthophosphate 17-18 ppm 12-14 ppm

pH 7.3-7.4 7.7-7.8

Active polymer 30 ppm 22.5 ppm

Cycles ~4.0 ~5.0

Results

• Discharge compliant

• 25% acid reduction

• Water reduction

• Excellent corrosion

protection of <1.0

mpy

• Excellent system

cleanliness – no scale

• Environmental

compliance

US$135,000/year savings

38 /GE /

Thank you

advance scale control technology for cooling water … f/advance scale control...

Documents