SPEAKER CONTACT/TOPIC ABSTRACTamtaorg.com/library/PC-1-04_VoutchkovNikolay.pdf · 2000-08-31 · SPEAKER CONTACT/TOPIC ABSTRACT American Membrane Technology Association (AMTA) 2409

SPEAKER CONTACT/TOPIC ABSTRACT

American Membrane Technology Association (AMTA) 2409 SE Dixie Hwy. Stuart, FL 34996 772-463-0820 772-463-0860 (Fax) [email protected] www.amtaorg.com

Please provide the following information and email to [email protected] or fax to: 772-463-0860. If you are presenting on multiple topics during this event, please fill out one form for each topic.

Name: Nikolay S. Voutchkov Suffix: P.E., D.E.E. Job Title: President (i.e.: Ph.D., P.E., Jr.) Company: Water Globe Consulting Mailing Address: 200 Broad Street, Suite 2450 City: Stamford State/Province: CT Postal Code: 06901 Country: USA Telephone: 203-504-8343 Cell Ph: 203-253-1312 Fax: 203-504-8342 Email: [email protected] Website:www.water-g.com

1. Speaker Biography (please provide one paragraph – 150 words or less)

Mr. Nikolay Voutchkov has over 25 years of experience in the field of water and wastewater treatment, and reuse. Currently he is an independent techncial advisor to public utlities and private technology development conpanies in the US and abroad. As a former chief technology officer for Poseidon Reseources, he led permitting and engineering of the 50 MGD Carlsbad and Huntington Beach seawater desalination projects in Southern California, and other large seawater desalination facilities in the US and abroad. Mr. Voutchkov is a registered professional engineer and a diplomate of the American Academy of Environmental Engineers. He is also a member of AMTA, IDE, the European Desalination Society and AWWA. Mr. Voutchkov is author of over 40 technical articles and several books in the field of desalination, water and wastewater treatment, and reuse. He is one of the principal authors of the AWWA Manual on Reverse Osmosis and Nanofiltration, the WHO 's Desalination Guidance.

2. Topic Title (please provide the topic title for your presentation) Latest Developments in Pumps and Energy Recovery 3. Topic Abstract (please provide a brief description of the topic session that you will present and how it applies to

both water operators and wastewater operators).

This presentation provides an overwiew of the types and key performance parameters of high pressure reverse osmosis system feed pumps and energy recovery devices widely used for seawater desalination today. Recent technological and equipment developments are disucussed and evaluated in terms of their effects on plant operation and overall energy use. The presentaton describes alternative types of pumps and energy recovery devices, and explains their key advantages and disadvantages.

mailto:[email protected]

AMTA/ADC Pre-Conference Workshop Desalination Technology Developments & Improvements

Austin, TX – July 13, 2009

AMTA/ADC - Pre-Conference Workshop 1

AMTA - America’s Authority in Membrane Technology

Latest Developments in Pumps and Energy Recovery

Nikolay Voutchkov, PE, BCEE Water Globe Consulting

©AMTA /ADC July 14, 2008



Presentation Overview

High Pressure Pumps – Technology Trends;

Energy Recovery Technologies – Present and Future.



75% to 85% of Desalination Plant Energy Used by the SWRO System

Energy is Lost Mainly Due to: • Pump/Motor Efficiency Constrains; • Limited Energy Recovery from Concentrate. • Energy Losses During Membrane Separation.

High Pressure Pumps Concentrate



Types of SWRO High Pressure Pumps

Reciprocating (Positive Displacement/Piston) Pumps;

Applications Typically Limited to 1.0 MGD;

90 % to 95 % Efficiency;

Flat Pump Curve – Efficiency and Flow Constant at Changing Membrane Pressures.

Centrifugal Pumps: Available in All Sizes;

82 to 88 % Efficiency;

Pump Efficiency Varies with Changing Membrane Pressure.



Positive Displacement (Piston) Pumps – Key Features

Fixed Flow Independent of Pump Operating Pressure.

Rotating Motion of the Motor is Converted to Reciprocating Motion to Drive the Pistons.

Delivered Capacity Fluctuates with:

Number of Pistons;

The Area of the Pistons;

Stroke Length;

Operating Speed – Often Run at ½ Speed to Reduce Maintenance (Reduces Efficiency to 80 – 85 %);



Piston Pumps – Flow Variation & Control

All Piston Pumps Deliver Pulsating Flow;

Flow Pulsation (Difference between Min and Max Flow) Depends on the Number of Pistons:

2 Pistons – 46 %;

3 Pistons – 23 %;

7 Pistons – 4 %;

9 Pistons – 2 %.

Installation of Multiple Pumps with Common Suction Header Typically Creates Severe Vibration Problems – Suction Stabilizers and Pulsation Dampeners – A Must!

CAT triplex pump



Centrifugal Pumps

Horizontally Split-case Multistage Pumps: Most common for large applications (>1,000 gpm);

Typically Yield Highest Efficiency (80 – 88 %).

Segmental Ring (Ring-section) Multistage Pumps: Unit flow rates – 350 to 1,000 gpm;

Popular for Medium Feed Flows – lower costs at reasonable efficiency.

High-Speed Single-Stage Pumps: Typically Used for Small Plants (50 gpm – 600 gpm);

Often Combined w/ Turbochargers.



Horizontally Split-Case Multistage Pumps

Casing Split in two Pump Halves;

Seawater Guided from Stage to Stage by Set of Volute Passageways;

Opposing Impeller Design – Allows to Reduce Net Axial Trust;

Larger, More Rugged, More Expensive Than Segmental Ring Pumps.



Horizontally Split-Case Pumps

Capacity – 3.8 MGD to 19 MGD Power Input – 1,500 hp to 9,000 hp

2 Stages in Large Sizes (12 – 14”) 4 Stages in Smaller Applications



Ashkelon - Largest High Pressure Pumps In Use Today

Two Sets of 3+1 Two-stage Horizontal Split-case Pumps – 16 MGD each;

Pump Motors – 7,000 hp;

5-year Pump Efficiency Guarantee;

All Wet Parts Made of Duplex Stainless Steel.



Radially Split Case Pumps

Occupy Less Space;

Easier to Maintain;

Less Vibrations;

Only One Mechanical Seal of the Drive End (Axial – 2 seals);

Internal Fiber-Composite Bearings (Water Lubricated) – vs. External Grease Lubricated;

Largest Pumps Installed for Expansion of Dhekelia SWRO Plant (Cyprus) to 10.5 MGD;

Unit Capacity – 7.0 MGD (2,800 hp) – 87 % Efficiency.



Radially Split High Pressure Pumps will be Used in Sydney, Australia

©AMTA /ADC July 13, 2009 12

Sydney SWRO Plant

12+1 KSB HP HGM-RO 8/3 Pumps

2,000 KW each 87 % Efficiency

One Pump per SWRO Train



Segmental-Ring Pumps

Individual Pump Stages Located Between Pump Suction and Discharge Casings;

Impellers Mounted on Common Shaft;

Smaller Diameter;

Lighter Construction;

Lower Cost.



Centrifugal Pumps – Key Considerations

Pump Efficiency Increases with Square Root of Speed for the Same Flow;

Speed – typically 3,000 to 3,500 rpm (up to 12,000 rpm);

Shaft size and required NPSH increase with Speed;

Limit Pump Speeds to 3,500 rpm.

Pump Curve Flattens with Increase of Number of Stages;

Pump Efficiency Increases with Flow for the Same TDH.



Maximizing Pump Efficiency – Bigger Pumps Rule!

Pump Efficiency ~

n x (Q/H)0.5x (1/H)0.25

Where:

n = pump speed (min -¹);

Q = nominal pump capacity (m³/s);

H = pump head (m).

Pump Efficiency:

One Pump Per Train – 83 %;

One Pump Per 2 Trains – 85 %;

Three Pumps Per 16 Trains – 88 %.

Carboneras, Spain – One Pump per 2 RO Trains

Ashkelon, Israel – (3+1) 7,100-hp Pumps per 16

RO Trains



Maximizing Energy Recovery



Hydraulic Turbocharger

Turbocharger Popular for Small and Medium Size Plants (20 to 40 % pressure boost).

Available for Low & High Pressures.

Used for High-Recovery (Brine Conversion) Systems to Achieve 60 – 65 %.

Low Maintenance & Brine Leakage Into Feed Stream.

Lower Cost and Space Requirements than Other Energy Recovery Systems.

TurboBooster

Courtesy: PEI



Energy Recovery System Incorporates Pump of Improved Efficiency


0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0 200 400 600 800 1000 1200 1400 1600 1800 2000 2200 2400 2600 2800

Feed

Pum

p Ef

ficie

ncy

Feed Flow (m3/h) AVS Pump

AVS Single-Stage Pump

90 % Efficiency

ER Turbine (88 to 90 %

efficient)

Typical Energy Recovery Efficiency 75 to 80 %

Courtesy: PEI



Hydraulic Turbocharger – Large Installations (8.9 to 10 kWh/kgal)

30 MGD Plant in Jebel Ali, UAE: 9 RO Trains;

16 Single-stage HP RO Pumps.

Up to 525 psi of Boost;

HP RO Pumps Operating @ Full Flow @ ½ Pressure –

5-7 % Extra Efficiency.

9.2 MGD Plant in Thailand (PT Chemicals) - 10 kWh/kgal.

38 MGD NEWater Ulu Pandan Plant, Singapore

Pump Efficiency ~ n x (Q/H)0.5x (1/H)0.25



Turbocharger – Next Steps Centralized Brine Energy Recovery, Brine Pressure Flow, and Pressure Control;

Elimination of Feed Throttle Control Valves, VFDs on the HP Pumps and Brine Pressure Control Valves.

Combination w/ Single-stage HP RO Pump of High Efficiency for Capacities of Up to 12.7 MGD of Feed.

Combination w/ Large Multi-stage Pump

(4,200 gpm) –

Can Feed 2.5 to 3 MGD RO Train



Pelton Wheels – Majority of Existing Plants

Conversion Efficiency: 80 to 90 %



Pelton Wheels Limit Individual RO Pump Size to 5.5 MGD

Trinidad SWRO Pump and Pressure Exchanger System – The Largest in the World

Key Limitation of Pelton Wheel

Technology on Pump Efficiency

- Couples Pump

and Energy Recovery System



Pressure Exchangers Allow the Use of Larger Pumps/RO Trains

Pelton Wheel

Pressure Exchanger

Provides 40 - 42 % of the Energy



DWEER and ERI Pressure Exchangers

ERI PX Pressure Exchanger • 96% Energy Conversion Eff. • Smaller Footprint; • One Moving Part – Shaftless Rotor; • Rotor Hydrostatically Suspended in Ceramic Sleeve.

DWEER Exchanger • Positive Displacement Pistons Instead of Rotor; • LinX Valves Cause the Two Vessels to Exchange Functions before The Piston Completes Stroke.



ERI System – Current Status

Largest In Operation - Hamma (Algeria) – 50 MGD;

Largest in Construction – Hadera (Israel) – 72.3 MGD;

Base Unit – PX 220;

(0.3 MGD) in ops since 2002;

10 to 16 Units per RO Train (2.5 MGD – 4 MGD RO Train).

Challenges: Mixing – 5 to 7%

Efficiency Decreases w/ Increase in Plant Recovery.



Perth SWRO & Pressure Exchanger Systems



ERI – New Energy Recovery Equipment PX 260

- 18 % Larger Capacity than PX220;

- Wider Flow Paths to Higher Throughput @ Minimum Pressure Losses.

Titan 1200 - 500% Larger Capacity than

PX220;

- Similar Overall Energy Recovery (Slightly Lower Efficiency Compensated by Lower Mixing);

- Side-ported Design Allows to Maximize Flow Production.

Courtesy: ERI



ERI System – Titan 1200

Can Handle 5 Times More Flow than PX 220 (1.4 MGD of Brine Flow);

16-inch Protec Pressure Vessel;

Energy Efficiency – 96.6 %;

Reduced Mixing of Brine Feed and Leakage – from 6 % to 2.3 %;

Testing Continues @ 4.6 MGD Los Cabos SWRO Facility, Mexico;

Market Release Planned for 2010.

Courtesy: ERI


AMTA - America’s Authority in Membrane Technology ©AMTA July 13-16, 2009 29

ERI Equipment – What is in the Pipeline?

CompPX - SWRO 8-inch Vessels Similar to PX 220 &

PX 260

Side-ported design

Maximized Production.

PX-240 – Brackish Water RO For Brackish RO Applications

Target Efficiency @ 90 % Under

Brackish RO Pressures (<450 psi)

Currently Operating on Facility in Turkey.



DWEER System – Current Status Tuas, Singapore

Triple DWEER 1100 3.6 MGD SWRO Trains

Used in Ashkelon (86 MGD) and Singapore (34 MGD);

1.3 MGD SWRO Train – One DWEER System – Model 1100;

Ashkelon – 2 x 40 DWEER 2200 Systems;

RO w/ DWEER - 2.0 to 2.5 kWh/kgal Less Energy than Pelton Wheel (45 % Rec.).



DWEER – Recent Large Projects

Gold Coast, Australia – 33 MGD;

Sydney, Australia – 66 MGD/132 MGD;

Aguilas, Spain – 48MGD.




Calder AG (Flowserve) – ROVA 300

Can Handle 1.9 MGD of Brine Flow (Three Times Bigger than Existing Units);

Duplex Stainless Steel;

New Seal Design Reduces Brine Mixing < 1.5 %.

Currently Tested in Oman and Cayman Islands.



KSB SalTec DT Pressure Exchanger

Electronically Controlled Rotating

Valves Adjust System Operations

Ring-section HP RO Pumps (87.5 % Efficient) &

Split-case Booster Pumps

1 MGD Units

Installed in Plants In Malta, Murcia,

(Spain), and Oman.



Two SalTec 250 Units Operating in 12 MGD Pembroke SWRO Plant (Malta) since July 2008




Reducing Power Use In Small Plants A Hair Rising Challenge?

Small Systems Still Use A Lot

of Energy

26 kWh/kgal

0.1 MGD Vs.

11.3 kWh/kgal For 50 MGD

Plant



Improving Energy Recovery – Small SWRO Plants

Clark Pump Danfos Axial Piston Pump-Axial Piston Motor


AMTA - America’s Authority in Membrane Technology ©AMTA July 13-16 2009

37

Pearson Pump – Combined Pumping & Energy Recovery

Pearson Pump (Spectra Watermakers) – Introduced in March 2009

Recovery Ratios – 20, 30 and 50 %;

Speed 600 to 1,200 rpm

Clark Pump + Energy Recovery Amplifier (up to 3,000 gpd);

Energy Recovery – 80 % ;

Seawater Energy Use - 10 kWh/kgal;

Next Generation – 12,000 to 30,000 gpd Units



Axial Piston-Pressure Exchanger X-Pump System

Ocean Pacific Technologies

• ~56% energy savings ~9.1 kWh/kgal (100 gpm)

~67% energy savings ~8.7 kWh/kgal (460 gpm)

• Fixed recovery – not influenced by pressure rise, salinity or temp.

• Low Complexity (water used for lubrication) – 90 % Pump Efficiency.

X-pump Pumps 100 % of the RO Feed/ If exchanger piston are selected @ 60 %, then RO will be fixed at 40 % Recovery

HP Inlet 100/60 bar

HP Outlet 60/59 bar

X-pumpTM Seawater Inlet 100/1 bar

Electric Motor

Reject Outlet 60/1 bar

Permeate 40/0.3 bar



Summary and Conclusions

Key Trend - Going Bigger!

Bigger Pumps;

Bigger Pressure Exchangers;

Bigger Turbochargers.

Large Pumps Allow Pushing the Envelope of Efficiency to ~ 90 %;

Horizontally Split Case Multistage HPRO Pumps Dominate!

Radially Split Case Pumps Have Made a Successful Debut!

Pressure Exchangers Facilitate the Use of Large Pumps and Pressure Center/Three-Center Designs.

Small SWRO Systems Are Nearing Energy Efficiency of Large Plants.



Nikolay Voutchkov

Questions ?

Nikolay Voutchkov, PE, BCEE Water Globe Consulting

[email protected]

Documents

SPEAKER CONTACT/TOPIC ABSTRACTamtaorg.com/library/PC-1-04_VoutchkovNikolay.pdf · 2000-08-31 · SPEAKER CONTACT/TOPIC ABSTRACT American Membrane Technology Association (AMTA) 2409