03_Filter_Performance_Efficiency_Penetration_MPPS_DifferentialPressure_120314 (2).pptx

7/29/2019 03_Filter_Performance_Efficiency_Penetration_MPPS_DifferentialPressure_120314 (2).pptx

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Filter Performance,

Efficiency, Penetration,Differential Pressure

Product Line Industrial Filtration TechnologyStatus: March 2012

Product Training


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Agenda

Efficiency + Penetration Definition of Efficiency + Penetration

Particle Filtration Mechanisms + MPPS

Differential Pressure Influencing Values of Differential Pressure

Filter Performance


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Agenda

Efficiency + Penetration

Definition of Efficiency + Penetration


Differential Pressure Influencing Values of Differential Pressure

Filter Performance


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Efficiency and Penetration

FilterConcentration or Quantity (of

particles) at filter outlet Co

Concentration or Quantity

(of particles) at filter inlet Ci

Quantity of particles upstream and downstream

a (depth) filter can be measured e.g. by particle counter

Quantity of particles on a depth filter

are difficult to measure!


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FilterConcentration or Quantity


Ci = 100 Particles


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Filter

90 Particles retained by filter

Concentration or Quantity (of

particles) at filter outlet Co

Co = 10 Particles passed the filter

Concentration or Quantity



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100%

C

CCE

i

oi

%100)

C

C1(E

i

o

%100filterupstreamparticlesofQuantity

filterbyretainedparticlesofQuantity

EfficiencyE

or

%90%100)100

101(E

Example:

Ci = 100 particles; Co = 10 particles

Efficiency = 90%


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100%

filterupstreamparticlesofQuantity

filterthepassedparticlesofQuantitynPenetratioP

%100C

CP

i

o

Example:

Ci = 100 particles; Co = 10 particles

%10%10010010P

Penetration = 10%


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P100%E

Conclusion:

E = 100% - 10% = 90%


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%100)

filterupstreammparticles/ofNumber

filterdownstreammparticles/ofNumber1(E

%100)filterupstream/mmg

filterdownstream/mmg1(E

oil

oil

Filter Efficiency and Penetration can be related to

different definitions of concentrations.Some examples

%100)filterupstreamppm

filterdownstreamppm1(E

oil

oil

ppmwt= mg/kg

ppmVol= ml/m


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Efficiency and PenetrationCalculation Example:

Oil aerosol concentration atfilter inlet Ci = 15 mg/m

Oil aerosol concentration at filteroutlet Co = 0,1 mg/m

Which filter efficiency is needed to achieve the required outlet concentration?

%3,99%100)15mg/m0,1mg/m1(%100)

CC1(E

i

o

Filter element grade M (micro filter) achieves an oil aerosol efficiency of

99,7%

???


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10.000 Particles

90%Efficiency

99%Efficiency

99,9%Efficiency

99,99%Efficiency

10% Penetration

= 1.000 particles

1% Penetration

= 100 particles

0,1% Penetration

= 10 particles

0,01% Penetration

= 1 particle


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Agenda




Differential Pressure

Influencing Values of Differential Pressure

Filter Performance


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Particle Filtration Spectrum

Aerosols and Solid Particles

0,01 0,1 10 1001 10000,001

Viruses

Particle Size [ m ]

Vapour, fumes, smoke Dust Mist Spray

10000

Droplets, Grains

Bacteria Drifting Sand

Gas Molecules Flour

Grains of Salt Pollen

Dried Milk Spores

Pigments Human Hair

Soot Cement Dust

Tobacco Smoke Coal Dust

Oil Vapor Water Clouds

Perceptible under microscope Visually PerceptibleSubmicroscopic Perceptible


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Primary Particle Filtration Mechanisms(Fibrous Media)

DiffusiveInterception

Fiber

Parameter Change Efficiency

Particle

Diameter

Fiber / Pore

diameter

Air Velocity

Temperature

Air Viscosity

Retention Mechanism Retention of smaller contaminations (< 0,1m)

Diffusive Interception

D = (1/vdf* CKT) / (3Nydp)

D = Diffusion Coefficient

V = Velocity of air

C = Cunningham correction factor

K = Boltzmann constantT = Kelvin temperature

df= Fiber Diameter

Ny = Air viscosity

dp = Particle diameter


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Interception

Fiber

Retention Mechanism Retention of larger contaminations (> 0,5m)

Interception


Particle

Diameter

Fiber

Diameter

R = dp / df


df= Fiber diameter


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Inertial Impaction

Fiber


Particle

Diameter

Air Velocity

Fiber / Pore

diameter

Air Viscosity

Particle

density

Temperature

Retention Mechanism Retention of larger contaminations (> 0,5m)

Inertial Impaction

M = (Cpvdp2) / (18Nydf)

M = Inertia parameter

v = Velocity of air

C = Cunningham correction factor

p = Particle densitydf= Fiber Diameter

Ny = Air viscosity



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Gravity

Fiber

Fiber

Fiber

Retention Mechanism Retention of larger contaminations (> 1m)

Gravitational Settling


Particle

Diameter

Air Velocity

Air Viscosity

Particledensity

Temperature

G = (Cpgdp2) / (18NyV)

G = Settling parameter

g = Gravitational constantC = Cunningham correction factor

p = Particle density

Ny = Air viscosity

V = Air Velocity



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Sieving

Fiber

Fiber

Fiber

Retention Mechanism Retention of larger contaminations (> 1 m)

Sieving


Particle

Diameter

Fiber

Diameter


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+Electrostatics

Fiber

Retention Mechanism

Retention of contaminations with different

electric charge than fiber


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0%

20%

40%

60%

80%

100%

0,01 0,10 1,00 10,00

Particle Diameter (m)

Efficie

ncy

Diffusion

Regime

Diffusion

and

Interception

Regime

Inertial

Impaction

and

Interception

Regime


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0

10

20

30

40

50

60

70

80

90

100

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

Efficienc

y(%)

Particle Size (microns)

Total

Diffusion

InertialInterception

Sieving

MPPS =

Most Penetrating Particle Size [m]


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Fractional Efficiency

1 2 3 4 5 10 300,01 0,02 0,03 0,05 0,1 0,2 0,3 0,5 10050200

10

20

30

40

50

60

70

80

90

100

Mobility Diameter[m]

Fractionalefficienc

y[%]

Aerodynamic Diameter [m]

6,7% at MPPS = 0,29 m

Filter medium for retention of particles approx. > 3 m


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Fractional Efficiency

1 2 3 4 5 10 300,01 0,02 0,03 0,05 0,1 0,2 0,3 0,5 20 50 100

0

10

20

30

40

50

60

70

80

90

100

Mobility Diameter [m]

Fraktionsabscheideg

rad[%]

Aerodynamic Diameter [m]

72,2% at MPPS = 0,14 m

Filter medium for retention of particles approx. > 1 m


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Agenda






Filter Performance


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Cost of Differential Pressure

After-cooler, Separators+Filters,

Dryers, Pressure Vessels, Valves,

Pipelines, Fittings,

6 bar

7 bar = 6 bar + 1 bar

+ 1 bar + 10% energy cost

Reduced flow Extended running time

+ 8K additional compression temperature

Additional cooling energy needed

Compressor Differential Pressurep = 1 bar

7 bar

Application


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Differential Pressure of Filters

p1 p2p1 > p2

Flow through a filter always creates differential pressure!

p = p1 p2


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Differential Pressure of Filters

Totalp =

p Filter Housing p Filter Element

+


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Agenda






Filter Performance


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0

20

40

60

80

100

120

140

160

180

0 0,1 0,2 0,3 0,4 0,5 0,6

Flow Velocity Filter Element [m/s]

Dp[mbar]

p Filter Medium

p Filter Housing

p Entire System

Volume Flow + Flow Velocity

+


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0

20

40

60

80

100

120

140

20% 40% 60% 80% 100%

Nominal Flow

deltap[mbar]

1bar a

2bar a

3bar a

4bar a

5bar a

6bar a

7bar a

8bar a

Operating Pressure


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Binder containing glass fibres

Binder-free glass fibres

Synteq XP

Filter Media


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Filter Manufacturing Technology

Wrapped Filter Media

Pleated Filter Media

Binder containing glass fibres


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0

20

40

60

80

100

120

140

160

180

200

20% 100%

Nominal Flow

DifferentialPressur

e[mbar] p at wet condition

(at certain oil viscosity)

p at dry condition

Wetting of Filter Media


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Particle Contamination of Filter Media


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Volume Flow + Flow Velocity

Operating Pressure

Filter Media

Filter Manufacturing Technology

Wetting of Filter Media

Particle Contamination

Summary


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Filter Performance

Filter Performance is defined by

Efficiency and Differential Pressure

Efficency

[%]

DifferentialPressure[m

bar]


Efficiency


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Filter Performance

Efficency

[%]

DifferentialPressure[m

bar] Required

Efficiency level

Best

efficiency

High

p

High

efficiency

Lowestp

Good

efficiency

Highest

p

Efficiency

too low!


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Filter Performance

0

25

50

75

100

125

150

175

200

225250

275

300

325

350

375

400

425450

475

500

Competitor A

(pleated)

Competitor B

(pleated)

Competitor C

p[m

bar]

98

98,1

98,2

98,3

98,4

98,5

98,6

98,7

98,8

98,999

99,1

99,2

99,3

99,4

99,5

99,6

99,799,8

99,9

100

Efficien

cy[%]

Differential pressure (p) and retention rate (efficiency) according ISO 12500-1.

Comparable coalescence filter oil wetted steady state at 8 bar.

p p p p p p p p

Required Efficiency Level Grade S (Submicrofilter)

Donaldson


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Questions ?

03_Filter_Performance_Efficiency_Penetration_MPPS_DifferentialPressure_120314 (2).pptx

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