POWER

PWER/BPROS/TRMWBD10/eng/THS/09.10/CH/7268 © ALSTOM 2010. All rights reserved. Information contained in this document is indicative only. No 

representation or warranty is given or should be relied on that it is complete or correct or will apply to any particular project. This will depend on the technical and 

commercial circumstances. It is provided without liability and is subject to change without notice. Reproduction, use or disclosure to third parties, without express 

written authority, is strictly prohibited.

AQCS Service SOLUTIONS

Wet Scrubber Upgrade 

Air Quality Control Systems

The technology to effectively reduce 

your emission levels

Emission reduction: More stringent environmental regulations require improved 

solutions for exhaust flue gas cleaning. Alstom offers a full set of Wet Flue Gas 

Desulfurisation (FGD) Service solutions to upgrade your equipment to a high-tech 

design with optimum performance.

Integrated upgrade solutions: Alstom is committed to finding innovative solutions 

to existing Wet FGD systems with upgrades for increased performance and energy 

savings. As every Wet FGD system is unique, Alstom takes a tailored approach to 

determining the solution you need. We bring a full array of engineering expertise to the 

table to ensure that the solution meets your expectations for high performance, low 

energy consumption and reduced operating costs.

Alstom, one of the 

most trusted names 

in power generation, 

has all the experience 

and expertise to 

obtain the highest 

efficiencies with the 

lowest operating and 

maintenance costs.

Reliable solutions

Our customers can benefit from our upgrade solutions to reduce emissions and 

maintenance costs and extend the lifetime of existing equipment.

Reduced emission

Alstom offers a full set of upgrade solutions to meet your emission guarantee 

requirements. 

Increased efficiency

Alstom’s Wet FGD upgrade solutions includes optimising layout of spray headers 

and installation of wall rings to increase gas to liquid contact, for optimum 

efficiency of your systems. 

Lower energy consumption

Alstom’s new nozzle types and pumps significantly reduce your energy 

consumption. Newly developed design of tray and demisters will increase 

performance with less pressure drop. 

Lower operation cost

Operation costs are reduced due to continuously improved designs that operate 

in an efficient and reliable manner, based on extensive proven experience and 

innovative design.

Process optimization

Alstom has the process expertise to evaluate existing operations and tune the 

system for optimum performance.
Spray headers: Improved design for uniform flue gas coverage

The optimal alignment and distance between the spray headers 

and the nozzles enable a uniform distribution of the liquid 

(slurry) and the flue gas. Alstom’s design increases the gas / 

liquid contact and improves the SO2 removal efficiency at lower 

energy consumption. 

Wet Flue Gas Desulfurisation 

Nozzle types: Optimal droplet diameter and dispersion

Alstom increases the efficiency of the SO2 absorption with the 

optimum design and location on the spray bank of the spray 

nozzles. Our hollow cone and bi-directional nozzles are positioned 

with computer modeling to achieve optimised gas to liquid 

contact, scrubbing efficiency and reduce gas sneakage.

Wet FGD upgrade options:

Mist eliminators: Prevents droplets carry over at reduced 

pressure loss Alstom’s modeling of the mist eliminators, 

spacing and orientation minimises the droplet re-entrainment. 

Through extensive testing and experience, Alstom recommends 

the appropriate washing cycle that secures low pressure drop 

translating in energy savings and securing reliable operation.

For high efficiency 
 upgrade solutions

A WFGD system includes many components that need 

to be tuned for optimum scrubber system performance

Performance enhancing plates: Increased gas to liquid contact

Improved gas distribution for each spray level and reduced risk for 

areas with high gas velocities at scrubber wall can be achieved by 

upgrading with enhancing plates. The improved gas distribution 

will increase gas to liquid contact and result in more efficient SO2 

removal. 

Tray upgrades: Optimal velocity with additional perforated tray

Alstom’s tray design improves the optimal gas to liquid contact 

rate for incoming gas distribution. The tray installation has shown 

improved scrubbing performance and lower total operating energy 

consumption. 

Slurry preparation equipment: Ball mill, mixers & pumps

Alstom’s overall process expertise and assessment of current 

operation conditions will confirm any tuning needs for limestone 

preparation. The quality of limestone and proper grinding level in 

the ball mill is very important for most efficient SO2 removal.

 and low maintenance costs

Make-up WET Water Tank

FGD

ESP or Fabric Filter

Forces Oxidation

Pulverizer

AIR

Absorber

Reheater

(optional)

I.D Fan

ME Wash

Reclaim

Water Tank

Primary Dewatering

Ash Pond

Secondary 

Dewatering Gypsum

to Market

Landfill

Disposal

Cake Wash

(optional)

or
POWER

PWER/BPROS/TRMWBD10/eng/THS/09.10/CH/7268 © ALSTOM 2010. All rights reserved. Information contained in this document is indicative only. No 

representation or warranty is given or should be relied on that it is complete or correct or will apply to any particular project. This will depend on the technical and 

commercial circumstances. It is provided without liability and is subject to change without notice. Reproduction, use or disclosure to third parties, without express 

written authority, is strictly prohibited.

AQCS SERVICE SOLUTIONS

Air Quality Control Systems

Alstom knows how to engineer and size AQCS systems 

and provide performance guarantees for your upgrades

High expertise: Alstom has extensive experience on all types of Air Quality Control systems and installed the first full 

scale Wet Flue Gas Desulfurization system 1968. With more than 52000 MW installed Wet FGD systems on fossil fired power 

generation facilities, we have the knowledge to support customers for new and upgrade solutions to meet their environmental 

requirements.

High technology: Alstom has the expertise to engineer and size a complete AQCS system and will provide performance 

guarantees for your upgrades. We offer complete service contracts for operation and maintenance of your Wet FGD system.

Forced Oxidation Air: High quality gypsum 

Alstom’s innovative forced oxidation system (air blown into the 

reaction tank combined with agitators) leads to an efficient and 

complete chemical reaction in the slurry tank. A stable balance 

results in a high quality gypsum which can be sold commercially.

Recycle Pumps: Energy saving

Alstom’s advanced design of spray headers, nozzles and other 

components lead to optimal liquid flow and pressure drop. The 

upgrade design matches for high SO2 removal and reduced power 

consumption from the pumps.

“We are the ultimate leader of the installed base” 

T

Fresh water

F

Blower Humidifier Agitator

T

Fresh water

F

Blower Humidifier Agitator

Execution Centre Sao Paulo

Alstom Brazil

Av. Embaixador Macedo Soares, 

10.001

05307-200 São Paulo

Phone: +55 113 612 78 13

Execution Centre Milano

ALSTOM Power Italia Spa

Viale Edison, 50

20099 Sesto San Giovanni MI 

Phone: +39 022 434 837 31

Execution Centre Knoxville

ALSTOM Power Inc

9737 Cogdill Road, Suite 101

Knoxville, TN 37932 

Phone: +1 865 966 0550

+1 866 257 8664

Execution Centre Kolkata

ALSTOM Projects India Ltd 

Plot No. Y-13, Block - EP, Sector V

Salt Lake, 

Kolkata 700091

Phone: +91 334 006 01 46 

For more information contact your Alstom Service representative: 

Execution Centre Växjö

Alstom Power Sweden AB

Kvarnvägen 

Box 1233

SE-351 12 Växjö

Phone: +46 470 76 20 00

Execution Centre Cologne

Alstom Power Service GmbH

Friedrich-Ebert-Straße 

51429 Bergisch Gladbach

Phone: +49 220 484 32 70

Visit Alstom Power online: www.alstom.com/power