Measurement of dust resistivity and back corona in ...Mechanische Verfahrenstechnik technische universität dortmund Measurement of dust resistivity and back corona in electrostatic
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Fakultät Bio- & ChemieingenieurwesenMechanische Verfahrenstechnik
technische universität dortmund
Measurement of dust resistivity and back corona in electrostatic precipitators
D. Pieloth, M. Majid, H. Wiggers, P.Walzel
PiKo Workshop Universität Bremen / 31st March 2011
Fakultät Bio- und ChemieingenieurwesenLehrstuhl Mechanische Verfahrenstechnik
D. Pieloth, M. Majid, H. Wiggers, P. Walzel | 31.03.11
technische universität dortmund
PiKo Workshop Uni Bremen31st March 2011
2
Measurement of dust resistivity and back corona in electrostatic precipitators
Motivation
ElectroStatic Precipitators (ESP)
Dust resistivity measurement
•
•Experimental setup
• New measurement chamber
• Summary and Outlook
Particle diameter and dust resistivity
Measurement program
Dust resistivity
Outline
Back corona and the collection efficiency of electrostatic precipitators
Design
Fakultät Bio- und ChemieingenieurwesenLehrstuhl Mechanische Verfahrenstechnik
D. Pieloth, M. Majid, H. Wiggers, P. Walzel | 31.03.11
technische universität dortmund
PiKo Workshop Uni Bremen31st March 2011
3
Measurement of dust resistivity and back corona in electrostatic precipitators
Electrostatic precipitator•
Dust deposition pattern within an electrostatic precipitator
Fakultät Bio- und ChemieingenieurwesenLehrstuhl Mechanische Verfahrenstechnik
D. Pieloth, M. Majid, H. Wiggers, P. Walzel | 31.03.11
technische universität dortmund
PiKo Workshop Uni Bremen31st March 2011
4
Measurement of dust resistivity and back corona in electrostatic precipitators
Dust resistivity•
I = electric currentρ = resistivitys = layer thicknessA = area of collecting electrodej = current density
Decrease of E-Field strength in electrostatic participator due to voltage drop within the dust layer
Back discharge of already absorbeddust particles
Back corona due to overriding the E-Field strength within the dust layer
Drop of collection efficiency of electrostatic precipitators
Mean E-Field strength within the dust layer:
Fakultät Bio- und ChemieingenieurwesenLehrstuhl Mechanische Verfahrenstechnik
D. Pieloth, M. Majid, H. Wiggers, P. Walzel | 31.03.11
technische universität dortmund
PiKo Workshop Uni Bremen31st March 2011
5
Measurement of dust resistivity and back corona in electrostatic precipitators
Dust resistivity and the collection efficiency of electrostatic precipitators
Definition of dust resistivity ρ:•
R = resistance (Ohm’s law: I = U/R)s = layer thicknessA = area of collecting electrodeρ = dust resistivity
Source: Weber/Brocke
Influence of resistivity ρ on collection efficiency of electrostatic precipitators e.g. migration velocity
-> increase of resistivity ρ-> drop of migration velocity-> collection efficiency decreases
Fakultät Bio- und ChemieingenieurwesenLehrstuhl Mechanische Verfahrenstechnik
D. Pieloth, M. Majid, H. Wiggers, P. Walzel | 31.03.11
technische universität dortmund
PiKo Workshop Uni Bremen31st March 2011
6
Measurement of dust resistivity and back corona in electrostatic precipitators
Measurement of dust resistivity•
Experimental setup
Fakultät Bio- und ChemieingenieurwesenLehrstuhl Mechanische Verfahrenstechnik
D. Pieloth, M. Majid, H. Wiggers, P. Walzel | 31.03.11
technische universität dortmund
PiKo Workshop Uni Bremen31st March 2011
7
Measurement of dust resistivity and back corona in electrostatic precipitators
Measurement of dust resistivity•
Electrode arrangement
Fakultät Bio- und ChemieingenieurwesenLehrstuhl Mechanische Verfahrenstechnik
D. Pieloth, M. Majid, H. Wiggers, P. Walzel | 31.03.11
technische universität dortmund
PiKo Workshop Uni Bremen31st March 2011
8
Measurement of dust resistivity and back corona in electrostatic precipitators
Back discharge of already separated dust particles due to air flow•
Dust collecting plate within an electrode of an electrostatic precipitator
Adhesion of the upper dust layer within E-Field?
Influence of current density, dust properties, gas conditions?
Fakultät Bio- und ChemieingenieurwesenLehrstuhl Mechanische Verfahrenstechnik
D. Pieloth, M. Majid, H. Wiggers, P. Walzel | 31.03.11
technische universität dortmund
PiKo Workshop Uni Bremen31st March 2011
9
Measurement of dust resistivity and back corona in electrostatic precipitators
Particle diameter and dust resistivity•
Particles used in dust resistivity measurement(scanning electron microscope pictures)
Fakultät Bio- und ChemieingenieurwesenLehrstuhl Mechanische Verfahrenstechnik
D. Pieloth, M. Majid, H. Wiggers, P. Walzel | 31.03.11
technische universität dortmund
PiKo Workshop Uni Bremen31st March 2011
10
Measurement of dust resistivity and back corona in electrostatic precipitators
Particle diameter and dust resistivity•
Particles used in dust resistivity measurement(scanning electron microscope pictures)
Fakultät Bio- und ChemieingenieurwesenLehrstuhl Mechanische Verfahrenstechnik
D. Pieloth, M. Majid, H. Wiggers, P. Walzel | 31.03.11
technische universität dortmund
PiKo Workshop Uni Bremen31st March 2011
11
Measurement of dust resistivity and back corona in electrostatic precipitators
Particle diameter and dust resistivity•
Fakultät Bio- und ChemieingenieurwesenLehrstuhl Mechanische Verfahrenstechnik
D. Pieloth, M. Majid, H. Wiggers, P. Walzel | 31.03.11
technische universität dortmund
PiKo Workshop Uni Bremen31st March 2011
12
Measurement of dust resistivity and back corona in electrostatic precipitators
Particle diameter and dust resistivity•
Fakultät Bio- und ChemieingenieurwesenLehrstuhl Mechanische Verfahrenstechnik
D. Pieloth, M. Majid, H. Wiggers, P. Walzel | 31.03.11
technische universität dortmund
PiKo Workshop Uni Bremen31st March 2011
13
Measurement of dust resistivity and back corona in electrostatic precipitators
Particle diameter and dust resistivity•
Fakultät Bio- und ChemieingenieurwesenLehrstuhl Mechanische Verfahrenstechnik
D. Pieloth, M. Majid, H. Wiggers, P. Walzel | 31.03.11
technische universität dortmund
PiKo Workshop Uni Bremen31st March 2011
14
Measurement of dust resistivity and back corona in electrostatic precipitators
Particle diameter and dust resistivity•
Fakultät Bio- und ChemieingenieurwesenLehrstuhl Mechanische Verfahrenstechnik
D. Pieloth, M. Majid, H. Wiggers, P. Walzel | 31.03.11
technische universität dortmund
PiKo Workshop Uni Bremen31st March 2011
15
Measurement of dust resistivity and back corona in electrostatic precipitators
New dust resistivity measurement chamber•
Design aims
max. air temperature 500º Cstainless steeldefined dust layer thicknessbetter visibility of processes within chamberlower heat lossadhesion of dust (gas stream velocities)
new measurement chamber
Fakultät Bio- und ChemieingenieurwesenLehrstuhl Mechanische Verfahrenstechnik
D. Pieloth, M. Majid, H. Wiggers, P. Walzel | 31.03.11
technische universität dortmund
PiKo Workshop Uni Bremen31st March 2011
16
Measurement of dust resistivity and back corona in electrostatic precipitators
New dust resistivity measurement chamber•
Fakultät Bio- und ChemieingenieurwesenLehrstuhl Mechanische Verfahrenstechnik
D. Pieloth, M. Majid, H. Wiggers, P. Walzel | 31.03.11
technische universität dortmund
PiKo Workshop Uni Bremen31st March 2011
17
Measurement of dust resistivity and back corona in electrostatic precipitators
Schematic of new dust resistivity measurement chamber•
adhesion of dust (different gas stream velocities will be applied)
Fakultät Bio- und ChemieingenieurwesenLehrstuhl Mechanische Verfahrenstechnik
D. Pieloth, M. Majid, H. Wiggers, P. Walzel | 31.03.11
technische universität dortmund
PiKo Workshop Uni Bremen31st March 2011
18
Measurement of dust resistivity and back corona in electrostatic precipitators
New dust resistivity measurement chamber•
Detection of particle morphology effects on resistivity ρ and back corona under definedair conditions (Glass, γ- Al2O3, Limestone)
Experiments with dust layers collected with collecting plate during operation of an electrostatic precipitator(electrostatic precipitator, TU Dortmund)
Adhesion of dust particles on top layer of dust, detection of release of those particles into gasstream (Laser beam experiments)
Measurement program
Fakultät Bio- und ChemieingenieurwesenLehrstuhl Mechanische Verfahrenstechnik
D. Pieloth, M. Majid, H. Wiggers, P. Walzel | 31.03.11
technische universität dortmund
PiKo Workshop Uni Bremen31st March 2011
19
Measurement of dust resistivity and back corona in electrostatic precipitators
Summary and Outlook•
First results for dust resistivity measurement (dust particle diameter, air conditions)
Construction of new dust resistivity measurement chamber almost finished
Infrastructure for dust resistivity measurement in place(experience, measurement methods, electrostatic participator)
Vielen Dank for the financial support by
Thank you for your attention!
Measurement program with new measurement chamber will start soon
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