test of filter media according to en 1822 of filter media according to en 1822 thomas krinke &...

© 2007, TSI Incorporated

TSI Particle Seminars 2008

Test of filter media according to EN 1822Thomas Krinke & Hans-Georg Horn


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Outline

• Filtration – Basics• EN 1822 – Short Overview• Solution for EN 1822 conform characterization

of filter media


Efficiency, E = 1 - P

Penetration, P = Downstream ConcentrationUpstream Concentration

Mechanical Media: 100 nm < MPPS < 300 nmElectro-Static and Membrane: MPPS < 100 nm

Filter Testing – Introduction

Most Penetrating Particle Size, MPPS: Typically between 0.05 and 0.3 µm


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Filtration MechanismsAction of Brownian motion. Best capture with small particles, fine fibers and low velocities. Independent of particle density.

Particles travel along streamlines and are caught because of their size. Ratio of particle to fiber size is important.

Particles deviate from the streamlines due to inertia and impact on the fibers. Large particles, high density, high velocity and small fibers is most efficient.

Particle is attracted to the fiber by electrical forces.

Diffusion

Interception

InertialImpaction

ElectrostaticDeposition

Inertial Impaction

Brownian DiffusionInterception

FilterFiber

(-)(+)

Electrostatic Attraction


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Filter Efficiency Curve

0%

20%

40%

60%

80%

100%

0.01 0.1 1Particle Diameter [µm]

Effic

ienc

y

DIFFUSION

DIFFUSIONAND

INTERCEPTION

INTERCEPTIONAND

INERTIALIMPACTION


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Filter Penetration

0.1 1 100.01

Particle Diameter (µm)

% P

enet

ratio

n

0.001

0.01

0.1

1

10

100

Diffusion

Diffusionand

Interception

Inertial Impactionand

Interception

Most Penetrating Particle Size (MPPS)


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Effect of Particle Deposition Mechanisms and Flow Rate (Face Velocity) on Penetration and Most Penetrating Particle Size

Penetration versus Particle Size

PARTICLE SIZE - log scale

PEN

ETR

ATI

ON Diffusion Interception

ImpactionMPPS

lower velocity

MPPS

Decrease of face velocity

Leads toIncrease of MPPSDecrease of Penetration


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Filter Testing Standard EN 1822

• EN 1822 is the European test standard for HEPA & ULPA filters

• Certifies a filter's absolute minimum efficiency for all particles.

• Primarily used to certify air filters for clean room applications.

• The two-part EN 1822 test identifies the MPPS and challenges the filter with only these particles, creating an absolutely worst-case scenario (Schroth and Caesar 2001).


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• European Standard EN 1822 – 5 parts– 1822-1 Classification, performance testing, marking– 1822-2 Aerosol production, measuring equipment,

particle counting statistics– 1822-3 Testing flat sheet filter media (Standard for

3160)– 1822-4 Determining leakage of filter element (Scan

method, TSI components can be used)– 1822-5 Determining the efficiency of filter element

(TSI components can be used)


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Classification by En 1822 – 1HEPA & ULPA Filters

High Efficiency Particle Air Filter

Ultra Low Penetration Air Filter


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Example for Decrease of Number Concentration

1.0E-03

1.0E-02

1.0E-01

1.0E+00

1.0E+01

1.0E+02

1.0E+03

1.0E+04

1.0E+05

1.0E+06

1.0E+07

H10 H11 H12 H13 H14 U15 U16 U17Filter Type

Con

cent

ratio

n on

Cle

an G

as S

ide

[#/c

cm] 1.0E7 Particle/ccm on raw gas side

1.0E5 Particle/ccm on raw gas side


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The test has two steps:1. Determine the MPPS of the filter medium

considering the mean face velocity of the medium when pleated into the filter (EN 1822 part 3)

2. Test the filter element at its MPPS by filter scanning (EN 1822 part 4) for leak detection and integral (overall) filter efficiency measurement.For complex filter geometries where scanning is not appropriate, filter elements may be tested in a closed test duct (EN 1822 part 5). In this case, only the integral efficiency is measured.


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1822-3 Testing flat sheet filter media

• Filter manufacturers expect that media manufacturers supply a test certificate with the MPPS.

• Many filter customers expect 100% testing of product by the filter manufacturer.


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• EN 1822 allows two approaches:1.Monodisperse test aerosol and CPC(s)

2.Polydisperse test aerosol and OPC


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With monodisperse test aerosol and CPC(s)


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Atomizer with0.03% DEHS in Isopropanol1.6L/min

3080L with Neutralizer 3077, 5L/min Sheath Air

Neutralizer 3012

50 nm


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Neutralizer 3012

100 nm


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Neutralizer 3012

150 nm


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Creating Penetration Curvewith Monodisperse Aerosol

Particle Diameter

Pene

trat

ion

d n/d

logd

p

logdp

Particle Diameter

Pene

trat

ion


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With polydisperse test aerosol and OPC


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Disadvantages of OPCs for Determination of MMPS

• Comparatively poor size resolution (high resolution needed)

• No channels below 200 nm• Some filter media (e.g. electrostatic) can have

MMPS of below 50nm


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Monodisperse test aerosol and CPC(s)for determination of MPPS

• Biggest advantage:Excellent coverage of the possible size range for the MPPS.

• Disadvantage: More time needed to carry out test


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Instrument SolutionModel 3160 Fractional Efficiency Filter Tester

• Fully automated test solution, ideally suited for filter media development (R&D)– Can be used for a wide variety of media,

including very high efficiency media – Up to 99.999999% efficient– Fully automated to save test time– Components are industry standards

• Classifier with DMA• CPC detection

– Does NOT provide information about loading behavior

• For filter media tests (EN1822 part 3), – TSI model 3160 is fully compliant


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Model 3160 Flow Schematic

Rotometer

Diluter

Computer

PumpFilter

Filter

Filter

Filter Holder

Filter Flowmeter

Clean Air Supply

Upstream CPC

Downstream CPC

∆ P

Mixing Manifold

PumpFilter

Quick Test System

DilutionBridge

Neutralizer

Electrostatic Classifier

Pump

Bleed Flow System

Filter

Drier

Salt Atomizers

Oil Atomizers


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Instrument Solution (2)

• Provides key information about filter media performance, including:– Fractional filter efficiency– Determine most penetrating

particle size (MPPS)• Full featured graphical and

tabular outputs


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3160 Printouts


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Applications

• Filter media development and characterization• Relevant for any company manufacturing high

efficiency filter media– Many new particle air filters are being developed – New types of filter media is being developed to

build new filters– It’s important to know the characteristics of the

media


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3160 Operation and Setup Tips

• If downstream counts are <100 for some particle sizes consider lengthening sample time

• Monitor concentration periodically to detect problems with atomizers

• If penetration goes up again after (larger sizes) passing MPPS this is an indication of a downstream leak

• Salt and Oil give the same results (test it if you like). Use oil to minimize maintenance


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3160 Calibration• Instrument uses electrical mobility which is the

standard method for checking submicron particle sizes and CPC’s which are the concentration standard

• Flows and pressure drops can be independently verified

• Field Installation is provided with new instruments to verify performance

• We provide Field Service and Service Contracts when requested by customers


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3160 Features and BenefitsFeature Benefit

Automated Fractional Efficiency test Simpler and easier than developing this system from components

Includes computer and Windows software for current operating systems

Familiar Windows look and feel minimizes operation and training time

Flows and size controls are automatic or simple to use

Doesn’t require additional equipment or lots of time to set up tests

New expanded size range up to 0.8 microns

Provides information that previously required a different tester

Fast Test Mode Adds ability to use an instrument designed for fractional efficiency for fast quality control tests

Automatically adjusts concentration and test time to get the best results within the parameters you set

Eliminates the need to monitor the test for concentrations that are higher or lower than desired

test of filter media according to en 1822 of filter media according to en 1822 thomas krinke &...

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