Fouling vs. Availability CheMin › Publikationen › PDF › 2012 › Fouling_versus... · Fluegas...

CheMinFouling vs. Availability

Prewin Meeting at Coventry, June 19th-20th 2012 1

Fouling versus Availability

Introduction to Prewin Meeting, June 2012 on Fouling

(in a parallel session: the Fifa Euro 2012 at Poland and Ukraine)

Thomas Herzogwww.chemin.de

Fouling versus Availability

Introduction to Prewin Meeting, June 2012 on Fouling

(in a parallel session: the Fifa Euro 2012 at Poland and Ukraine)

Thomas Herzogwww.chemin.de



...the accumulation of unwanted material on solid surfaces to the detriment of function. Other terms used in the literature to describefouling include: • deposit formation, • encrustation, • deposition, • scaling, • scale formation, • slagging, • etc.

Source: Wikipedia

Fouling is...

Final-superheater, cladding besidecoating, reliable operation time: 18-

24 month



Availability is...

...this raises interest to prolong the operation time from 12 to 18 or 24 month

Availability is the most important factor...

relative %

Cost of Capital(Investment)

Staff Costs

Electr. & Gas/Oil

Consumables & Residues

Maintenance

Troughput,Tonnage of

Waste

RecoveredEnergy

100

90

80

70

60

50

40

30

20

10

0Expenditures Revenues

Directlyproportional to

throughput

Prices decrease

Overcapacities & decrease of

available wastequantities

Each ton of waste andeach day of operationincreases availability,

and the revenues

Increasing

Increasing

Increasing

Increasing

Decreasing

Zickert 2009



...why is it interesting, to prolong the operation period?

Availability 90% to 95% :

• Operation period of 12 month at 95% availability: 18 days for maintenance

• Operation period of 24 month at 95% availability: 36 days for maintenance

This is not enough to do proper maintenance work andto have further days for short inspection and cleaning jobs

Enough for proper maintenance work andfor further days for short inspection and cleaning jobs



Efficiency (Heat Recovery) is one aspect of availability...

Q.

Fouling

Water/ Steam

Flue Gas

Fouling reduces the heat recovery...

...high fouling rates increase the demand for cleaning stops = Loss of availability....waste, refuse derived fuels, biomass cause severe fouling in general.

...and culminates in blockages



Fouling influences availability in many ways

kick-off

Fuel Firing

Fouling

Red Team ‚Difficult Fuels‘ Blue Team ‚Availability‘

beat availability by fouling



Fouling influences availability in many ways

Fuel Firing

Fouling

Design

Tactic 1: Generate fouling Defense: Designed for solid fuels

goal keeper



Designs for high fouling rates in biomass incineration...

Source: Burmeister & Wain Energy A/S

...biomass incineration with superheaters using the radiative heat transfer in the 1st pass

...typical technique used in Scandinavia for straw firing (potassium)

...high alloyed steels are required for parts or for full construction of the platen*

*): Published materials are e.g. X3CrNiMoN17-13, TP347CG, TP347FG, 12Cr1Mo1W, 13Cr13Mn, Esshete 1250, HCM12, X20CrMoV121, AC66, Sanicro 28/ 63, Sandvik 8RE



Designs for high fouling rates in waste-to-energy plants...

...test phase in German wte-plant

...commonly used steel tubes protected by rear-ventilted tiles

Projekt TUF01HTO-32881 „Steigerung der Energieeffizienz von Verbrennungsanlagen für Nicht-Regelbrennstoffe durch

Strahlungsüberhitzer im ersten Kesselzug“CheMi

n



Fuel Firing

Corrosion

Tactic 2: Corrosion under deposits

Design

Fouling

Cause damage,reduce life time of components,

reduce operation time andtroughput of waste



Tube

Fluegas

subsequent corrosion

Chlorides inside the deposits release corrosive chlorine gas

matterheat

°Ctemperature activatesreactive salts(vapour pressure)

barrierCladding



Investigations on fouling rates and corrosion with cooled deposition probes

Analysis of:...Fuel & firing condition...Fouling rate...Heat Transfer [W/m2]...Corrosion mechanism...Material tests (coating, cladding)...Different temp. on one probe...Analysis of flue gas flow pattern



Fuel Firing

Corrosion

Tactic 2: Corrosion under deposits Defense: Corrosion protection

Design

+ manymore

...expensive players,which are reliable

Fouling

Cladding

Refract.

Coating

Standard results must be:1:0 for corrosion protection



Fuel Firing

Tactic 3: Confuse the defenseby nasty center players

Design

Corrosion+ manymoreCladding

Refract.

Coating

Fouling

DischargePressure

DropRaw Gas Qual.



Fouling is not a stable condition, it changes continuously (15 min/ picture)

Cladding

Rear-ventilatedtile

Back-filledtile

Left Side Front Wall Right Side

High

Low

Heatflux q.

kW/m2



Fuel Firing

Fouling

Tactic 3: Confuse the defenseby nasty center players Defense: Online cleaning

DesignMan to man cover:Individual defense

at individual positions

ShowerWaterBlower Explosion


Refract.

Coating

DischargePressure

DropRaw Gas Qual.



Fuel Firing

Fouling

Tactic 4: Cause more confusion!

Design

DischargePressure

DropRaw Gas Qual.

Provocation of a self-goalShowerWater

BlowerExplosion


Refract.

Coating



Online cleaning



Online cleaning

Water Blower



Online cleaning

Laser inside theWater Blower



Fuel Firing

Fouling

Design

Discharge

PressureDropRaw Gas

Qual.

ShowerWaterBlower Explosion


Refract.

Coating

IR-Camera HeatfluxMeasurem.

Control fouling to achieve availability



Thank you for your attentionThank you for your attention

Fouling is not bad at all, it contains e.g. up to 5-7 weight% copper and might be an ore deposit.



CheMin stands for “Chemistry” and “Mineralogy” since 1996

Structure:• Owned by Dr. Wolfgang Spiegel• Situated in the south of Germany (Bavaria), in the city of Augsburg• 4 project manager working in teams of 2-5 persons • External senior experts provide knowledge the the 1970ies• In total: approx. 35 employed mineralogists, chemists and engineers



CheMin stands for “Chemistry” and “Mineralogy” since 1996

Activities:

• In incineration plants for solid (waste, refuse derived, biomass, coal...) and gaseous fuels

• On the fuels, firing conditions, materials and residues

• Grate and fluidized-bed, in boiler/ superheater and flue gas treatment

• Hot topics: Boiler efficiency (dewpoint corrosion on ECO), operation period 18 to 24 month

• In D (many), A (6), NL (4), CH (4), RUS (2), DK (1) ...UK (not yet)

• Mostly for plant owners (from municipalities and industries to energy giants)

frequently for plant manufacturers and deliverers (refractory lining, cladding and coatings)

• German legal status of “Sachverständiger” (expert witness) – neutral status

• Research and development together with several German companies

• Networks: German association VGB and European Network PREWIN

Fouling vs. Availability CheMin › Publikationen › PDF › 2012 › Fouling_versus... · Fluegas...

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