31 March 2011

Bongi Cindi

SD & L – Filter Bag Presentation

ContentsContents

• Filter Principle of Operation Filter Principle of Operation

• Advantages and Disadvantages Over ESP’sAdvantages and Disadvantages Over ESP’s

• Filter Types and Filter Cleaning MethodsFilter Types and Filter Cleaning Methods

• The Thermal Power Fabric Filter Plant ComponentsThe Thermal Power Fabric Filter Plant Components

• Fabric Filter Plant CAPEX ComponentsFabric Filter Plant CAPEX Components

• Fabric Filter Plant OPEX ComponentsFabric Filter Plant OPEX Components

• Related Industries in South AfricaRelated Industries in South Africa

• Way ForwardWay Forward

• Filter Principle of Operation Filter Principle of Operation

• Advantages and Disadvantages Over ESP’sAdvantages and Disadvantages Over ESP’s

• Filter Types and Filter Cleaning MethodsFilter Types and Filter Cleaning Methods

• The Thermal Power Fabric Filter Plant ComponentsThe Thermal Power Fabric Filter Plant Components

• Fabric Filter Plant CAPEX ComponentsFabric Filter Plant CAPEX Components

• Fabric Filter Plant OPEX ComponentsFabric Filter Plant OPEX Components

• Related Industries in South AfricaRelated Industries in South Africa

• Way ForwardWay Forward

Filter Principle of OperationFilter Principle of Operation

• Gases (and also liquids) are separated from dispersed particles by passing it through a fabric “medium” with a large surface area

• Particles that are not able to penetrate the medium will be retained on its surface, forming the so-called “filter cake”

• The filter cake is equally important to the actual filtration process as the medium.

Source: Klingspor and Vernon, 1988Source: Klingspor and Vernon, 1988

Advantages

• Filter systems are the main alternative for Electro Static Precipitators (ESP’s) systems

• Offer very high collection efficiencies of typically above 99%, over rather large size ranges

• Performs well in high electric resistivity ashes

Advantages

• Filter systems are the main alternative for Electro Static Precipitators (ESP’s) systems

• Offer very high collection efficiencies of typically above 99%, over rather large size ranges

• Performs well in high electric resistivity ashes

Advantages and Disadvantages Over ESP’sAdvantages and Disadvantages Over ESP’s

Disadvantages

• Larger pressure drop

• The low allowable gas velocity making them larger than ESP plants

• High capital expenditure than ESP’s

Disadvantages

• Larger pressure drop

• The low allowable gas velocity making them larger than ESP plants

• High capital expenditure than ESP’s

Eskom Position

• Currently Eskom power stations has mix of ESP’s & fabric filter plants (FFP’s)

• Based on the effectiveness of the filter bag technology to reduce emissions, Eskom is planning to embark on fleet to replace all ESP’s with FFP’s

• There are immediate capex opportunities to localise on the fabrication and installation of FFP’s

• There are opex opportunities for industrialisation of the filter bag fibre

Eskom Position

• Currently Eskom power stations has mix of ESP’s & fabric filter plants (FFP’s)

• Based on the effectiveness of the filter bag technology to reduce emissions, Eskom is planning to embark on fleet to replace all ESP’s with FFP’s

• There are immediate capex opportunities to localise on the fabrication and installation of FFP’s

• There are opex opportunities for industrialisation of the filter bag fibre

Filter Types and Filter Cleaning MethodsFilter Types and Filter Cleaning Methods

1. Reverse air cleaning1. Reverse air cleaning

2. Pulse-jet cleaning2. Pulse-jet cleaning

3. Shake/deflate systems3. Shake/deflate systems

Source: Soud, 1995Source: Soud, 1995

The Thermal Power Fabric Filter Plant ComponentsThe Thermal Power Fabric Filter Plant Components

Source: HitachiSource: Hitachi

Fabric Filter Plant CAPEX ComponentsFabric Filter Plant CAPEX Components

Design

Civil

• Foundations

• Columns

• Structural Steel

Mechanical

• Bags, Fabric & Support

• Housing & cladding

• Collection hoppers

• Discharge devices

• Filter cleaning device

• Fans & ductingElectrical• Motors• Cables• C&I• Switchgear

Design

Civil

• Foundations

• Columns

• Structural Steel

Mechanical

• Bags, Fabric & Support

• Housing & cladding

• Collection hoppers

• Discharge devices

• Filter cleaning device

• Fans & ductingElectrical• Motors• Cables• C&I• Switchgear

Opportunities

To maximise local content on fabrication and installation

Opportunities

To maximise local content on fabrication and installation

Fabric Filter Plant OPEX ComponentsFabric Filter Plant OPEX Components

Fibre Material

Bag filters made of fabric fibre materials, textile, plastics and ceramics

Factors determining process quality are removal efficiency

Fibre Material

Bag filters made of fabric fibre materials, textile, plastics and ceramics

Factors determining process quality are removal efficiency

Surface morphology of new fiber at 3,000x magnificationSurface morphology of new fiber at 3,000x magnification

Surface morphology of new fiber at 7,500x magnificationSurface morphology of new fiber at 7,500x magnification

Surface morphology of used fiber at 3,000x magnificationSurface morphology of used fiber at 3,000x magnification

Surface morphology of used fiber at 7,500x magnificationSurface morphology of used fiber at 7,500x magnification

Fabric Filter Plant OPEX Components……… contdFabric Filter Plant OPEX Components……… contd

Fibre MaterialFibre Material

Typical fabrics used for bagsTypical fabrics used for bags

GenericName

FiberMaximum temperature Acid

ResistanceAlkali

ResistanceFlex abration

resistanceRelative

cost

Continuous Surges

°F °C °F °C

Natural fibercellulose

Cotton 180 82 225 107 poor excellent average 0.4

Polyolefin Polypropylene 190 88 20093

excellent excellent good 0.5

Natural fiberprotein

Wool 200 93 250 121 good poor average 0.8

Polyamide Nylon 200 93 250 121 poor to fair excellent excellent 0.6

Acrylic Orlon® 240 116 260 127 very good fair average 0.7

Polyester Dacron® 275 135 325 163 good fair excellent 0.5

Aromaticpolyamide

Nomex® 400 204 425 218 fair very good very good 2.0

Fluorocarbon Teflon® 450 232 500 260 excellentexceptpoor forfluorine

excellentexceptpoor for

trifluoride,chlorine,

andmoltenalkalinemetals

fair 6.7

Glass Fiberglas®or glass

500 260 550 288 good poor poor to fair 1.0

Polymer P84® 450 232 500 260 good fair fair 2.5Polymer Ryton® 375 191 450 232 excellent excellent good 2.5-4.0

Sources: McKenna and Turner 1989 and Greiner 1993.Sources: McKenna and Turner 1989 and Greiner 1993.

Fabric Filter Plant OPEX Components ……… contdFabric Filter Plant OPEX Components ……… contd

Fabric Manufacturing process• Woven fabrics:- filters are made of yarn with a definite repeated pattern

• Felted fabrics:- filters are composed of randomly placed fibers compressed into a mat and attached to loosely woven backing material

• Membrane filter:- is a special treatment where a thin, porous membrane (expanded polyfluorocarbon) is bonded to the scrim, or support fabric.

Fabric Manufacturing process• Woven fabrics:- filters are made of yarn with a definite repeated pattern

• Felted fabrics:- filters are composed of randomly placed fibers compressed into a mat and attached to loosely woven backing material

• Membrane filter:- is a special treatment where a thin, porous membrane (expanded polyfluorocarbon) is bonded to the scrim, or support fabric.

Cross-section of filter at 25x magnificationCross-section of filter at 25x magnification

Opportunities

All needling of fabric to be localised

Opportunities

All needling of fabric to be localised Source: freepatentsonline. Source: freepatentsonline.

Fabric Filter Plant OPEX Components ……… contdFabric Filter Plant OPEX Components ……… contd

Bag Manufacturing processBag Manufacturing process

Welding of filter cageWelding of filter cage Filter cageFilter cage

Filter BagFilter Bag

Final ProductFinal Product

Bag stitchingBag stitching

Typical industrial applications for baghouses

Shaker Reverse-air Pulse-jet

Screening, crushing, and conveying of rock products Low temperature steel applications Metal working Mining operations Textiles Woodworking processes Chemical industry Food industry Coal-fired boilers

Cement kilns Lime kilns Electric steel furnaces Gypsum calcining Ore smelters and roasters Sintering plants Rock dryers Foundries Carbon black Magnesium oxide kilns Coal-fired boilers

Pharmaceuticals Food industry Woodworking Sinter plants Metal working Foundries Textiles Chemical industry Coal-fired boilers Asphalt batch plants Municipal waste incinerators

Related Industries in South AfricaRelated Industries in South Africa

Filters are used in many other SA industries to aggregate volumes for industrialisation of filter bags

Filters are used in many other SA industries to aggregate volumes for industrialisation of filter bags

Way ForwardWay Forward

Eskom is looking at Industry to provide input into the fabric filter bag (FFB) strategy, especially on the process around

manufacturing of the bags

Eskom is looking at Industry to provide input into the fabric filter bag (FFB) strategy, especially on the process around

manufacturing of the bags

ENDEND