FUNDAMENTALS OF LIQUID FILTRATION & FILTER · PDF fileFUNDAMENTALS OF LIQUID FILTRATION & FILTER TESTING Christophe PEUCHOT, ... oil filter → injectable solute ... up to 40 mg/L

Filtration 2009, 18-19 November 2009, Chicago, IL

FUNDAMENTALS OF LIQUID FILTRATION & FILTER TESTING

Christophe PEUCHOT, CEO

Jerry LYNCH, President

International Filter

Testing

Services Inc

DIA

09-3

5

Filtration 2009, 18-19 November 2009, Chicago, IL2

CONTENT

INTRODUCTION

SCOPE / NEED

THEORIES OF LIQUID FILTRATION

CHARACTERIZATION OF PARTICLES/SUSPENSIONS

CHARACTERIZATION OF POROUS MEDIA/FILTERS

1

2

3

4

5

CONCLUSION6

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•

SCOPE

SOLID-LIQUID

MIXTURES

CLARIFIED LIQUIDS

RECOVERED SOLIDS

SOLID-LIQUID SEPARATION

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CLARIFICATION OF A LIQUID

Swimming

pool water

Drinking

waterInjectable Solutes

Wastewater Food oil

Sugar

Milk

Machining

fluid

Pharmaceutical proteins

EXPRESSION OF THE NEED

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EXPRESSION OF THE NEED

RECOVERY / DEHYDRATION / UP GRADING OF SOLIDS

CoalSugar

Iron

ore

Phosphate

Grapes

wort

Waste

water sludge

Carbonate

Uranium ore

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EXISTING SOLUTIONS

SOLID-LIQUID SEPARATION TECHNIQUES & PROCESSES:

•

A broad

family

of available

technologies

•

2 Principles

: Difference

of «density»

+ Flow through

porous

media-

Sedimentation, Centrifugation, Cycloning, Flottation, Magnetic

-

Sieving, Filtration, Centrifuge filtration, Membrane Separations

•

Hundreds

of machines and products

Listed

in IFTS’

TECHNOTHEQUE (Technical

Library)

•

Selection

optimisation : an expert task

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FILTRATION / CLARIFICATION OF LIQUIDS

Diversity

of liquids, applications, aims

and requirements

Coarse

engine

lube

oil

filter

→

injectable solute

sterilizing

membrane filter

Broad variety

of filters

and filtering

media

Often

one product

= several

applications

Many

suppliers, open market, strong

competition

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FILTRATION / CLARIFICATION OF LIQUIDS

Behaviour

directly

linked

to application: products

and conditions

Choice

by steps

= selection

on brochure claims, lab/pilot trials, final validation, purchase

Need

for clear

statements

of performance

Test methods

and equipments

Standardization

= agreement between

parties suppliers

/ end users

/ testing

organisations

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AVAILABLE FILTRATION TECHNIQUES

Deep

bed

Belt

Precoat

Cartridge

Disc

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FILTERING MEDIA FOR LIQUID CLARIFICATION

GRANULAR

UNIT GRAINS, POWDERS AND FIBERS

FOR DEEP BEDS (thickness

> 30 cm)

-

SAND, ANTHRACITE, CHARCOAL, GRENAT,

-

IN OPEN OR CLOSED FILTERS

FOR PRECOAT FILTERS (filter

aids)

-

DIATOMITES, PERLITES, CELLULOSE FIBERS, WOOD FLOUR,

-

ROTATING DRUMS, FRAME, DISCS, CANDLE FILTERS

A DISCONTINUOUS PROCESS

-

BACKWASHING

-

DISPOSAL OF CLOGGED MEDIA

MAINLY USED ON HIGH FLOWRATE FILTERS FOR THE CLARIFICATION OF LIQUIDS

Sand

Diatoms

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FILTERING MEDIA FOR LIQUID CLARIFICATION

Wire

mesh

Cellulose nitrate

membrane

Polycarbonate membrane

Glass micro fibers

Cellulose paper

Syntheticnonwoven

STRUCTURED (MADE)

WOVEN FABRICS

-

WIRE (metallic) or THREAD (synthetic)

NON WOVENS AND «

PAPERS

»

-

FIBERS OF CELLULOSE, GLASS-

POLYMERIC (melt

blown, spun

bonded,…)

STACKS OF RINGS or DISCS

-

BEAD or FIBERS-

METAL, PLASTIC, CERAMIC

MEMBRANES

-

CERAMIC-

POLYMERIC

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NON WOVEN AND SINTERED FILTERING MEDIA

STRUCTURE MATERIALS BINDING TECHNIQUE SHAPE

PAPERS

(fibers)

CELLULOSE

GLASS MICROFIBERS

COTTON

RESINSPLEATED

ROLLED

NON WOVEN

SYNTHETIC FIBERS

Polypropylene, polyamide,

Polyethylene, polyester, PTFE, PVC, …

THERMOFUSING

RESINS

SINTERING

INTERLACING

PLEATED

ROLLED

METALLIC FIBERSSINTERING

INTERLACING

WOUND

ROLLED

SINTERED WIRESYNTHETIC

METALLIC-

ROLLED

WOUND

SINTERED BEADS

METTALIC

PLASTIC

CERAMIC

SINTERINGTUBES

PLATES

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MEMBRANES

Organic Mineral

Cellulose ester/acetate/nitrate, Polysulfone, acrylonitrile, PFE,

polyamide, PVDF, polycarbonate, nylon

Ceramic, carbide, aluminate,

zirconium or titanium

oxyde

1 –

DEFINITION

A thin

(e < 300 µm), microporous

(0.05 < MPS < 10 µm) and homogenious

structure which

can

be

supported

2 -

NATURE

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3 -

MANUFACTURING

POLYMERISATION / EVAPORATION

IRRADIATION / SELECTIVE DISSOLUTION

WARM STRETCHING

DEPOSITION / COOKING

MEMBRANES

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MEMBRANES

4 -

IMPLEMENTATION

PLEATED CARTRIDGES

MONO or MULTICHANNEL TUBES

DISC STACKS

SPIRAL MODULES

HOLLOW FIBRES

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TECHNOLOGY OF FILTERING CARTRIDGES

TYPESWOUND, AGGLOMERATED

PLEATED, ROLLED, DISCS, CAPSULES

CONSTITUTION

SUPPORT AND INTERFACES

. Central tube (perforated)

. CAGE = external

perforated

tube or grid

. END CAPS

. SEALS (flat, O-ring), …)

FILTERING MEDIA –pleated, stacked

or rollet)

. AT LEAST TWO LAYERS

protection

Prefilter

(s)

Filtering

media

Drainage

Support

. STICKED OR WELDED TO END CAPS

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TECHNOLOGY OF CARTRIDGE FILTERS

TYPES-

MONO or MULTICARTRIDGES

Up to 20 housing

-

VARIOUS MATERIALS

Stainless

steel, aluminium, steel, polycarbonate,

PVDF, PTFE, PVC, screwable, clampsable, …

ACCESSORIES (and functions)-

EVENT AND FLUSHING OUT

-

CLOGGING INDICATOR

Mechanical, electrical, …

-

BYPASS VALVE

-

ANTIDRAIN VALVE

-

SEALS (O-RING, FLAT, …)

-

SPRINGS

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APPLICATIONS OF CARTRIDGE FILTERS

APPLICATION AIMS RATING SUITED FILTERS

PREFILTRATION

COARSE FILTRATION (SIEVING)

PROTECTION OF A FINER FILTER

«

CLARIFICATION

»

OF VISQUOUS FLUIDS (varnish, syrups, cosmetics, …)

PROTECTION OF A MOVING PART (pump, valve, …)

REDUCTION OF SOLID CONTENT

S >

10 µm

WOUND

AGGLOMERATED

PLEATED NON WOVEN (one layer)

ROLLED TABLECLOTH

PLEATED WIRE MESH

FILTRATION

CLARIFICATION (less

turbide) (beverage, perfumes, solvents, …)

TROUBLE REDUCTION (water, varnish, …)

REDUCTION OF PARTICULATE CONTENT (cleanliness

classes : hydraulics, injectable solutes, …)

PROTECTION OF MOVING PARTS

PREFILTRATION FOR STERILISING FILTERS

0.5<S<10 µm

PLEATED (several

layers)

ROLLED TABLECLOTH

DISCS or LENS

CAPSULES

STERILISATION

REDUCTION OF COLLOIDS CONTENTS

RETENTION PYROGENES, BACTERIA AND VIRUSES

COLD STERILISATION

ULTRAPURE FLUIDS (microelectronics)

S < 0.5 µm

PLEATED CARTRIDGES

CAPSULES

DISCS or LENS

BEVERAGE

NUCLEAR

MICROELECTRONICS AEROSPACE

HEALTHCARE

CHEMISTRY

FLUID POWER

AUTOMOBILE

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THEORIES OF LIQUID FILTRATION : FLOW

Flow of liquid through porous media

•

Darcy law

•

Bo

= permeability (mm2

or Darcy)

P = f (media + fluid)

0BAzQP

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THEORIES OF FILTRATION : EFFICIENCY

Filtration efficiency = capture mechanisms

•

Mechanical sieving ↔ particle size

•

Electrostatic attraction

•

Approach to the media surface

Sedimentation –

Hydrodynamics –

Inertia –

Diffusion

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THEORIES OF FILTRATION : CLOGGING

Filtering media clogging

d2t/dV2

= (dt/dV)n

Pore Total Clogging

Pore Progressive Clogging

Pore Partial Clogging

Cake Filtration

n=2 n=1

n=3/2 n=0

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FILTERING MEDIA CLOGGING

LAWS OF FILTRATION

0

kV0

2

00

2/120

0

02

0kt0

00

0

kt0

n

q1

q1kVeqq

2kV1qqqqkV)V(fq

)tkq1(qq

q1

q1kt

1V2k

qqeqq)t(fq

q1V

2k

Vt)ktq1ln(kV

q1t

2k

Vt)e1(qV)t(fV

0n1n23n2n

dVdtk

²dVt²d

gingllogcginglogcginglogcCakePartialogressivePrTotalFunction

essurePrttanConsLaws1982HERMIA1936BREDEEHERMANS

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THEORY OF CAKE FILTRATION

Constant Pressure

Constant Flow Rate

Centrifuge Filtration

PRV

Pvt s

22

QRtQP s2

2

0

1

2

3

4

5

0 0.5 1 1.5 2 2.5 3V (m3) x 104

t/V (s

.m-3) x

10-7

ΔP2Aωαμ

2cPA

R m

rf

rc ro

Pc

HQf

)²r²r(²21P f0l

])rRs()

rr

(Ln)1([

PH2Q

0c

0s

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CHARACTERIZATION OF PARTICLES/SUSPENSIONS

INTRINSIC

Density, Particle Size Distribution, Concentration, Turbidity,

Viscosity, Surface Tension, Specific area, Surface Charge

BEHAVIORAL

Filterability, Compressibility, Settling rate, Specific resistance,

Rheology, CST, …

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INTRINSIC CHARACTERISTICS

Viscosity

Surface Tension

Contact Angle

dCosP /4

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INTRINSIC CHARACTERISTICS

Concentration

Turbidity

Surface Charge

NTU

mg/L

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INTRINSIC CHARACTERISTICS OF PARTICLES

PARTICLE SIZE

1 dimension

?

2 dimensions

r

a

(r,l)As many dimensions as possible directions of measurement → Equivalent diameter

= “Diameter of the sphere with the same behaviour

with the property chosen”

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PARTICLE SIZE ANALYSIS

EQUIVALENT DIAMETERS

Optical :

Longest

dimension by microscopy

Projected

area by microscopy

and light extinction

Diffraction

Scattering

Physical

:

Sieving

Settling

velocity

Displaced

volume by electrozone

REPORT OF RESULTS

By mass, volume or number

Cumulative (d>x) or differential

(x1 < d < x2)

Tables, figures and codes

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PARTICLE COUNTING

MICROSCOPY

Transmitted or incident light at appropriate level

Magnification = f(sizes of interest) : 5 to 500 x

Membrane preparation (individuel objects)

Manual setting of grey level

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LIGHT EXTINCTION

DDéémonstrationmonstration auau LaboratoireLaboratoire

V

Signal (mV) =

particle projected surface area

Particle=

Shadow on photodetector

Light extinction

Above

1µm, up to 40 mg/L ISO MTD, Fuels, Drinking

water, Hydraulic

fluids, Pharmaceutics

PARTICLE COUNTING

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PARTICLE COUNTING

LIGHT SCATTERING

Below

3 µm, very

low

concentration (<100 part/mL)

Microelectronics, microfilter

testing

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PARTICLE COUNTING

ELECTROSENSING ZONE (COULTER)

(volume)

Variation of electrical

conductivity

of sensing

volume

Aqueous

liquids

or organic

ones

with

salts

Size ranges : 0.5 to 500 µm and more (sedimentation!)

Pharmaceuticals, chemicals, bioproducts,

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PARTICLE COUNTING / SIZING

Volume of fluid

analysed

(N = V x C)

Bottle

sampler = controled

volume

Online sampler = controled

(flow rate + time) or volume

Coïncidence error

= several

particles

in the sensing

zone at

the

same

time

Noise level

= minimum electronic

(mV) tension below

which

particles

are not detected

Resolution

= ability

to differentiate

particles

with

very

close sizes

FACTORS OF INFLUENCE

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PARTICLE SIZE ANALYSIS

Particle

Size analysis by laser diffraction (NF X 11-666)

Ref. Imphy Loire - Pas d'ultrason - N° IFTS : 3814

0

10

20

30

40

50

60

70

80

90

100

0,01 0,1 1 10 100 1000 10000

Diametres (µm)

Pass

ant c

umul

é en

%

Ref. Imphy Loire - Pas d'ultrason - N° IFTS : 3814

0

0,5

1

1,5

2

2,5

3

3,5

0,04 0,5 1,1 2 5 8,5 14 20 38 63 95 140 190 400 1000 1600 2200

Diametres (µm)

Dis

trib

utio

n re

lativ

e en

%

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PARTICLE COUNTING/SIZING

Samples

representativity

: mix, disperse, degas

Particle

settling

Overlimit

concentration

Microbubbles

Immiscible or different

refractive

index liquids

Dilution ratio

Viscosity

and flow changes

Electrical

parasites

Mechanical

vibrations

SOURCES OF ERROS

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COUNTING/SIZING INSTRUMENTS

COMMON REQUIREMENTS = SIZE CALIBRATION

CERTIFIED MONOSIZED SPHERES TRACEABLE TO REFERENCE TECHNIQUES : Microscopy

calibrated

with

certified

graticules

CERTIFIED POLYDISPERSED SUSPENSIONS

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Field contamination monitor (FCM)

PORTABLE and ONLINE SYSTEMS

Doc. PARKER

Hydraulic

systems: aerospace, petroleum, earth

moving, mining, paper

millsFuels, lubricants

PARTICLE SIZE DISTRIBUTION/COUNTS

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COUNTING/SIZING INSTRUMENTS

Count and / or size

Type of distribution : number, mass, volume

Information looked

for (filtered

liquid, pulp

to settle, floculated

particles)

Sample

concentration, volume, flowrate,

Batch / On line –

Laboratory

/ Process

Environment

/ Operation

conditions

Accuracy

required

CRITERIA OF CHOICE

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Factors

of influence

Volume of fluid

analysed

(N = V x C)

Bottle

sampler = controled

volume

Online sampler = controled

(flow rate + time) or volume

Coïncidence error

= several

particles

in the sensing

zone at

the same

time

Noise level

= minimum electronic

(mV) tension below

which

particles

are not detected

Resolution

= ability

to differentiate

particles

with

very

close sizes

Calibration curve of an ACP

1

10

100

1000

10000

1 10 100

Size

Volta

ge (m

V) Noise level

> 4 µm c

0

100000

200000

300000

400000

500000

600000

700000

800000

0 1 2 3 4 5 6

Concentration (mg/L)

Par

ticle

cou

nts

/ 25

mL

ACP 95 % line

Coïncidence level


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Pore blockage

technique

Flow Decay

= P (particle

size / number)

Not particle

counting

but contamination

indication

Cannot

be

calibrated


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FILTER MEDIA PROPERTIES AND CHARACTERISATION

100A

V

VV

STRUCTURAL PROPERTIES

POROSITY

-

Defined

by the ratio of void

volume to apparent volume

-

Measured

by pycnometry

-

Expressed

as a percentage

(%)

-

Not to be

confused

with

«

Filtration Rating

»

(in µm)

Not in micron !

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STRUCTURAL

PROPERTIES

PORE SIZE DISTRIBUTION

-

Equivalent pore = capillary

tube of same

diameter

as the actual

pore

-

Measured

by air porometry

(not more Mercury)

-

Application of JURIN’s

law

using

a known

wetting

liquid

P = air pressure

= contact angle

= surface tension

d = «pore»

diameter

dCosP

4

Air

θ

Wetting

Liquid


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0

0,5

1

1,5

2

2,5

3

3,5

4

4,5

5

0102030405060

Pore diameter (µm)

Diff

eren

tial f

low

rate

(%)

Maxi diameter : 23.15 µmMini diameter : 7.988 µm50% diameter : 15.01 µm

Filter ref. XXX (IFTS 1619)PORE SIZE DISTRIBUTION

-

The pressure of appearance

of the first flow (the lowest

pressure) defines

the Buble

Point used

to check the integrity

of a filtering

cartridge

-

Shape of curve

helps

in predicting

filtration behaviour

(surface or depth

clogging)

Bubble

Point

Pressure

Air

flow

Dry

Wet


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HYDRAULIC PROPERTIES

PERMEABILITY

-

Defined

by DARCY law

µ

= liquid

viscosity

z = media thickness

Qe

= liquid

flowrate

(laminar) AF

= filtration surface area

∆P = applied

pressure

-

Characterizes

the porous

media only

HEAD LOSS

-

∆P vs flow velocity

in m3

/ m².h

(media)

-

∆P vs flow rate in m3

/ h (filter)

-

Measured

with

standard or real fluid

(viscosity)

-

Applied

to size filter

cartridge

and housing

PAzQµB

F

eO


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DETERMINATION OF ∆P vs Q CURVE

TYPICAL

TEST STAND


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HYDRAULIC PROPERTIES

CURVE OF DIFFERENTIAL PRESSURE vs FLOW RATE

Pressure drop measurement generated by oil flowrate through filter element

0

5000

10000

15000

20000

25000

30000

0 10 20 30 40 50 60 70 80 90

Flow rate (L/min)

DP

(hPa

)

24 cSt

300 cSt


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STANDARD MEASUREMENTS OF PERFORMANCE

DEFINITIONS

EFFICIENCYAbility

to retain

suspended

particulate

contaminants that

may

affect system or engine

durability, reliability

and performance

CAPACITYMass of solid

contaminant retained

by the filter

element

when

it

is

clogged

and needs

to be

replaced

ABSOLUTE RATINGSize of the largest

glass bead

able to pass

the filter

element

BEHAVIORAL PROPERTIES : SEPARATION EFFICIENCY

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SEPARATIVE PROPERTIES

ABSOLUTE RATING

-

Diameter

of the largest

glass bead

passing through

the media or the filter

in standard conditions

-

Since

nothing

to see

with

reality, no discussion on meaning

of results

-

Very

accurate

and repeatable

-

Allows

tiny

differenciation

of media

-

Standard method

MIL F 8815


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FILTRATION EFFICIENCY

-

Characterises

the ability

to retain

suspended

matters

-

Defined

by the ratio of what

is

retained

to what

is

offered

-

Determined

by measuring

turbidity, concentration, numbers

of particles

at

various

sizes

-

Quantified

by a percentage

or a ratio

or a Log Reduction

Value

-

Varies with

operating conditions and throughout

filter

life

A B

A

BAE 100%

11100%E

BA


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VARIOUS OPTIONS CHOOSEN BY PROFESSIONALS

Liquid: Water, mineral

oil, fuel, …

Multipass

or single pass

Particles:

silica

powders, carbon

black, iron

oxyde, microorganisms, …

Size distribution:

suited

to the pore size distribution to find

both

low

and 100 % efficiencies

Upstream

contaminant concentration:

level

and steady

or cyclic, few µg/L to 100mg/L

Analysis

technique:

overall

(gravimetry, turbidity) or particle

counts

per mL

in different

size ranges

Test time:

initial, throughout

life, average, minimum counts

per size range


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RETENTION CAPACITY (CR

)

-

Mass of solid

contaminants captured

until

a given

operating limit

is

achieved

-

Possible operating limits: given

∆P, percentage

flow reduction, time, particle

breakthrough

(loss

of efficiency),

-

Contaminants: silica, mixture of silica, sand, Fe2

O3

,

-

Measured

on a flat sheet

media what

allows

extrapolation

-

Often

measured

with

efficiency

(multi or single pass)

Cr’

= Mr

/ A (mg/cm2) (specific

retention

capacity)

BEHAVIORAL PROPERTIES :(Dirt

Holding Capacity)

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A. Contaminant injection circuitB. Filter test circuitC. Dilution and counting system

M

M

A B

C

M

A. Contaminant injection circuitB. Filter test circuitC. Dilution and counting system

M

M

A B

C

M

Typical

international standard test stand schematic


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Typical

European

standard test stand schematic

(drinking

water and industrial

liquid

cartridge

filters)


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0

2

4

6

8

10

12

14

16

0 20 40 60 80 100 120Injected mass (g)

Flow

rate

(L/m

in)

Pump A

Pump B

Example

of effect

of a poorly

specified

test equipment:Filtration Efficiency

and Retention

Capacity

of a drinking

water filtering

cartridgeper NSF 42§7.4 «

mechanical

reduction

testing

»

Influence of test pump

on time required

to reach

a 75% test flow rate decay

thuson mass of dust

retained

and thuson efficiency

claimed

0

2

4

6

8

10

12

14

16

0 10 20 30 40 50 60 70 80 90 100injected mass of ISO FTD (g)

Flow

rate

(L/m

in)

Pump A

Pump B

Cartridge B

Cartridge A

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INFLUENCE OF TEST PUMP

Cartridge B

On final efficiency

0

10

20

30

40

50

60

70

80

90

100

0 5 10 15 20 25 30 35

Particle size (µm)

Filtr

atio

n ef

ficie

ncy

(%)

Pump APump B

After injection of 89 g of ISO FTD

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FILTER TESTS STANDARDS : RECENT IMPROVEMENTS

IMPROVEMENTS TO ISO STANDARDS

•

MORE PRECISELY DEFINED AND CONTROLLED OPERATING CONDITIONS : TEMPERATURE, PRESSURE, FLUID CONDUCTIVITY, FLOWRATE, WAVE SHAPE, …

•

NEW TEST CONTAMINANTS (EFFICIENCY & CAPACITY)ISO 16889, ISO TR 13353, ISO 19438, ISO 4548-12

ACFTD →

ISO MTD (UF, F, C) (ISO 12103-1) →

NIST SRM 2806 (ISO TR 16144)

•

NEW AUTOMATIC PARTICLE COUNTER CALIBRATION

ISO 4402 →

ISO 11171 calibration→

ISO 11943 on-line counting

•

TEST STAND VALIDATION PROTOCOLS

•

INTERNATIONAL VALIDATION ROUND ROBIN20 to 30 laboratories

IMPROVED TESTS EASIER AND MORE RELIABLE COMPARISON

BUT STILL A LACK OF STANDARD DESIGNATION

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FILTRATION EFFICIENCY

typical

results: single pass

per EN 13443-2

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A big

step

forward

in NF 45-303, EN 13443-2 and ISO 19438 : clear

and standard definitions

of filter

ratings.

Reference

Filtration Rating (S µm)

: dimension, in micrometres, of the ISO MTD or ISO CTD particles at which the overall mean cumulative filtration efficiency of a filtering cartridge tested in accordance with the procedure described in this European standard, is greater than or equal to

99,8 %

Filter

Reference

Rating

: Particle

size (in µm(c)) corresponding

to an initial efficiency

or a cumulative overall

efficiency

of 99%.

All other

labels

(Nominal or Absolute) are only

commercial

ones. They

are meaningless

since

not standardised, i.e. not agreed

on by the filtration community

COMPARISON/QUALIFICATIONOF FILTER EFFICIENCIES

DIA

09-3

5


NEW MULTIPASS TEST : CYCLIC FLOW

Principle

: ISO CD 23369

DIA

09-3

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Test equipment

validation : wave

shape

0

500

1000

1500

2000

2500

3000

3500

4000

4500

0 10 20 30 40 50 60 70

Time (s)

Q a

nd P

Q = f(t)P = f(t)

CYCLIC MULTIPASS TEST RESULTS

DIA

09-3

5


CYCLIC MULTIPASS TEST

Test equipment

validation : wave

shape

+ online counts

stability

Comparative pressure drop with or without cyclic flowrate variation

0

2

4

6

8

10

12

0 20 40 60 80 100 120 140 160

Time (min)

P (b

ar)

Delta P - 20 L/min DP -20<->50 Lmin 1 Hz Delta P - 50 L/min DP (bar) 20<->50 Lmin 0,1 Hz

DIA

09-3

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1

10

100

1000

10000

100000

0 50 100 150 200 250 300

Time (min)

Part

icle

cou

nts

/10

mL

>4 µm c > 5 µm c > 6 µm c > 7 µm c > 8 µm c > 9 µm c > 10 µm c > 12 µm c>4 µm c > 5 µm c > 6 µm c > 7 µm c > 8 µm c > 9 µm c > 10 µm c > 12 µm c

UpstreamDownstream

Online particle

counts

CYCLIC MULTIPASSTEST RESULTS

DIA

09-3

5


Typical

average

efficiency curve

(15 mg/L)

-20

0

20

40

60

80

100

0 5 10 15 20 25 30 35

Particle size (> µm(c))

Filtr

atio

n ef

ficie

ncy

(%)

ISO CD 23369 (1) ISO CD 23369 (2) ISO 16889

Efficiency decreases when flow cycles

Co = 15 mg/L ISO MTDQT = 25-100 L/min ; f = 0.1 Hz

CYCLIC MULTIPASS TEST

DIA

09-3

5



LogNsLogNe

BACTERIAL RETENTION

-

LRV = LOG REDUCTION VALUE = -

STANDARD MICROORGANISMS-

STERILE CONDITIONS-

SPECIFIC GROWTH CONDITIONS

DIA

09-3

5


HIGH DIFFERENTIAL PRESSURE (Element

burst/collapse pressure)

- ٧ = 500 mm²/s- max ∆P = 350 kPa

by steps

of 25 kPa

during

1 min (or as agreed

between

parties)-

use particulate

contaminant or high

viscosity

fluid

to increase

∆P if requiered

MEASUREMENTS OF RESISTANCE TO VARIOUS STRESSES

DIA

09-3

5


HIGH TEMPERATURE

Immersion in hot fluid. E.g. lubricating

oil

filters·

2 x (96 h at

135 ±

2°C)·

Compare (Q, ∆P) before

and after

cooking

•

Circulation of hot fluid

through

clogged

media/cartridge

0

500

1000

1500

2000

2500

0 50 100 150 200 250 300 350 400

Temps (min)

Para

met

res

Température *10 (°C) Pression différentielle 2 (mbar) Pression différentielle 1 (mbar)

MEASUREMENTS OF RESISTANCE TO VARIOUS STRESSES

DIA

09-3

5


ALL MECHANICAL CHARACTERISTICS

FILTRATION RATING

→ CHOICE OF FILTER MEDIA TYPECompatibility, max ∆P, …

→ DEFINITION OF REFERENCE RATING XX

= 200 for hydraulic filters (ISO 16889)EX

= 99.8% for automotive filtersLubricants (ISO 4548-12) ; fuels (ISO 19438)

EX

= 99.8% for industrial filters (NF X 45-303)EX

= 99.8% for drinking water filters (EN 13343-2)

CLEAN DIFFERENTIAL PRESSURE→ EXPERIMENTAL MEASUREMENTS

∆P = f(VF

, ) VF & AF

mini

→ DARCY LAW

OMF B

ZµPQA

CRITERIA FOR CHOOSING AND SIZING CARTRIDGE FILTERS

DIA

09-3

5


CRITERIA FOR CHOOSING AND SIZING CARTRIDGE FILTERS

RETENTION CAPACITY (CR

)

→ CHOICE OF MEDIA ASSEMBLY

→ MAXIMUM ACCEPTABLE MASS OF CONTAMINANT

RETAINED BEFORE EFFICIENCY DECREASES

- CR

= g or C’R = g/m²

(specific)

-

Determined by standard testsISO 16889, ISO 4548-12, ISO 19438NF X 45-303, NF L 51-134, EN 13343-2

→ MASS OF “SOLIDS”

FILTERED (MF

)

MF

= CF

x QF

x

CF = solid concentration (mg/L)QF = filtrate flowate

(L/day)

= filter life (day)

FILTRATION SURFACE AREA

FF

R

QCC

R

RF C

CA'

DIA

09-3

5


STANDARD TESTING ALLOWS CLEAR COMPARISONS

PARTICLE COUNTS / EFFICIENCY

DIA

09-3

5


STANDARD TESTING ALLOWS CLEAR COMPARISONS

CLOGGING CURVES / CAPACITY

DIA

09-3

5


INTEGRITY TESTING

BUBBLE POINT AND PRESSURE HOLD TEST

dCosP

4

Pd

Wth

L

Relation RATING/BUBBLE POINT/PRESSURE DROP

DIA

09-3

5


CONCLUSION

Variety

of filtering

media

Methods

and apparatus

of characterization

of particles

and suspensions

Methods

and equipment

of characterization

of porous

media and filter

elements

Validation of test methods/stands and calibration of measuring

instruments

Standard methods

to make

results

comparable

Documents

FUNDAMENTALS OF LIQUID FILTRATION & FILTER · PDF fileFUNDAMENTALS OF LIQUID FILTRATION & FILTER TESTING Christophe PEUCHOT, ... oil filter → injectable solute ... up to 40 mg/L