11evonikupgrade baghouses

7/27/2019 11Evonikupgrade baghouses

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SUCCESSFUL OPERATION

OF BAG HOUSESWITH NEEDLE FELTS

Georg Rathwallner

Evonik Fibres GmbH


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Table of content

Bag house operating and maintenance costs

Bag material selectionBag condition monitoring

Typical failure patterns

Operating experience


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Bag house operation and

maintenance costs


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Table of content






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Peak temperature resistance of fibres

140150

200220

260260

0

50

100

150

200

250

300

PAN PES PPS m-Ar. PI PTFE

** ActualActual applicationapplication temperaturetemperature isis belowbelow thethe shownshown maximummaximum dependingdepending onon thethe flueflue gasgas

compositioncomposition andand bagbag lifelife expectationexpectation!!

PROCON


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Resistance on a scale from 1-4; 1 indicating the best value and 4 weak performance

< 24042-411Glass< 2404111PTFE

160-20012-41-21-2Polyimid

160-1802-33-43-42+Polyamidimid

160-1802-33-442M-Aramid

140-1702-31-213PPS

110-1303224+PAN

< 13033-444PET

cont. op.

temperature

filtration

efficiency

acidshumid

heat

oxidation

PROCON

Properties of filter bag materials


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Specific surface of different fibres

0

200

400

600

0

PROCONtrilobal

m-ARAMIDEPPS

FibreSurface(m/kg)

2,2 dtex round (206 m/kg)

Fiber Titre (dtex)

P84

P84 (polyimide)

Procon(PPS)

2,2 dtex

Procon

(PPS)1,7 dtex trilobal (317 m/kg)


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Filter bag materials by application

PAN


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Table of content


Bag material selection

Bag condition monitoring




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Table of content






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contamination from the clean

gas side - no penetrationthrough the felt

penetration through leakages

or holes

penetration through the felt

(insufficient filtration efficiency or

too frequent cleaning/too low

cleaning set point)


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Abrasiontypically related to high local gas velocity and dust load

bag materials show different abrasion resistance, but problems ofinhomogenious gas distribution have to be solved to get satisfactoryoperating behaviour


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Cracks

as a result of chemical ageing (loss of tenacity below critical limits)as a result of mechanical burden

e.g. as a result of dust penetration (high dp, frequent cleaning, internal abrasion)

As a result of damaged cages or contact between bags or bags and wall


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Membrane damage along a supporting cage wire- Penetration of dust into the glass fabric results in internal abrasion


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Table of content






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Comparative test in a finish mill operating conditions

2 similar grinding lines with ball mills

Bag filter :

size: 720 m

A/C ratio: 1,2-1,3 m/min

dust load: 500 g/m

Temperature: 85 C

As a result of an increase of the a/c-ratio the bag

life of the polyester felts dropped from 18 to 7months.

Problems with increasing differential pressure anddust emissions were experienced.


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Comparative test in a finish mill - felt construction

40-50 l/dm2min40-50 l/dm2minAir permeability @

200 Pa

Clean gas

side

scrim

Filtration

side

PETPETPETPET

600 g/m2600 g/m2Felt weight

differential pressure flange-flange:

1500 Pa,

stable for>48 months

Bag change after

7 months

Performance

40% P84 / 60% PETPET with scrim

Bag

construction

P84/Polyester

Polyester Fine

Fibre


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Another comparative test in a finish mill:

bag material after 29 months operation

65 6988-8939-42washed

(in a conventional laundry machine)

29-3439-4815-22after simulated pulse cleaning

15-1928-2913-14as received

PAN/PET

+P84

P84Glass/

membrane

Air permeability

[l/(dm.min) @ 200 Pa]


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CLINKER COOLER JAPAN

P84/P84, 4450 mP84/P84, 4450 m

Pulse Jet - On LinePulse Jet - On Line

TempTemp:: 150 C150 CACR:ACR: 1,04 m/min1,04 m/min

HH22O:O: 0-3 vol%0-3 vol%

OO22:: 20,5 vol%20,5 vol%

Emission: < 10 mg/NmEmission: < 10 mg/Nm

lifetime of filterbags: >5 years


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KILN/MILL FILTER NORWAY

P84/HybridP84/Hybrid scrimscrim, 17.200 m, 17.200 m

Pulse JetPulse Jet On LineOn Line

FlowFlow:: 2 x 230.000 Nm/h2 x 230.000 Nm/h

TempTemp:: 170-180C (170-180C (maxmax250C)250C)

ACR:ACR: 1,37 m/min1,37 m/min

HH22O:O: 14 - 20 vol%14 - 20 vol%

OO22:: 8 - 12 vol%8 - 12 vol%

SOxSOx:: 115 - 1.000 mg/Nm115 - 1.000 mg/Nm

NOx:NOx: 780 - 900 mg/Nm780 - 900 mg/Nm

DustDust:: 11 65 g/Nm65 g/Nm


# Compound & Kiln Op.# Incin. of Haz. Waste

# 2 x 3.584 Filterbags

# Start Up: October 1998

Lifetime: 8years


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KILN/MILL FILTER NORWAY

P84 bag after 8 years in

operation


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Kiln/raw mill filter UAE

100% P84,100% P84,

1689616896 bagsbags (160mm x 6000mm)(160mm x 6000mm)

appapp. 50.000 m. 50.000 m

Pulse JetPulse Jet On LineOn Line

FlowFlow:: Nm/hNm/h

TempTemp:: 150-200C (150-200C (maxmax 260C)260C)

ACR:ACR: 1 m/min1 m/min

HH22O:O: 9 - 18 vol%9 - 18 vol%

OO22:: 4 - 13 vol%4 - 13 vol%

SOxSOx:: 150 - 320 mg/Nm150 - 320 mg/Nm

NOx:NOx: 190 - 310 mg/Nm190 - 310 mg/Nm

DustDust:: 4040 170 g/Nm170 g/Nm



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SUCCESSFUL OPERATION

OF BAG HOUSESWITH NEEDLE FELTS

Georg Rathwallner

Evonik Fibres GmbH

11evonikupgrade baghouses

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