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Jerzy Mizeraczyk

XII INTERNATIONAL CONFERENCE ON ELECTROSTATIC PRECIPITATION Nuernberg May 9 – 13, 2011. PIV MEASUREMENTS OF ELECTROHYDRODYNAMIC FLOW IN ESPs. Jerzy Mizeraczyk. Ce ntre for Plasma and Laser Engineering The Szewalski Institute of Fluid - Flow Machinery Polish Academy of Sciences

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Jerzy Mizeraczyk

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  1. XII INTERNATIONAL CONFERENCE ON ELECTROSTATIC PRECIPITATION Nuernberg May 9 – 13, 2011 PIVMEASUREMENTS OF ELECTROHYDRODYNAMIC FLOW IN ESPs Jerzy Mizeraczyk Centre for Plasma and Laser Engineering The Szewalski Institute of Fluid-Flow Machinery Polish Academy of Sciences Gdańsk, Poland

  2. Motivation of laser investigations of flowpatterns inelectrostatic precipitators Interest in improving electrostatic precipitator (ESP) collection of fine particles (micron and submicron sizes). Howdoes the EHD flow caused by the presence of electric field andcharge in ESPs influence the particle precipitation process?

  3. OUTLINE • Laser flowvisualization • Principles of laser flowvisualization • ParticleImageVelocimetry (PIV) • Principles of of 2-dimensional (2D) and 3-dimensional (3D) ParticleImageVelocimetry • Products of PIV (flowvelocity field, flowstreamlines, vorticity map) • Example of PIVmeasurementsin a spike-to-plateelectrostaticprecipitator (ESP): • PIVmeasurement of thedustparticleflowstructures • Structures of thedustparticledeposits • Correlationbetweenthedustparticleflowstructures and thedustparticledepositstructures • Conclusions

  4. PRINCIPLE • OF PARTICLE IMAGE VELOCIMETRY (PIV) • Flow seeded with particles following the motion of the flow • Light source for illumination of the flow • Camera to capture 2 images of the motion of the seed particles 2 consecutive CCD images v = S / (t2 – t1)

  5. 2D PARTICLEIMAGEVELOCIMETRY - PRINCIPLE

  6. EXPERIMENTAL SETUP FOR 2DPIVMEASUREMENTS -cylindrical telescope to produce a laser beam sheet -CCD camera, tmin = 2 s, 1018x1018 pixels -image processor -PC computer The standard PIV equipment (Dantec PIV 1100): -a twin second harmonic Nd-YAG laser system capable of changing t = t2 – t1

  7. EXPERIMENTAL SETUP FOR 3D PIVMEASUREMENTS

  8. Products of PIV (flow velocity field, flow streamlines, vorticity map)

  9. Laser flowvisualization and PIV - example Study of thedustparticleflowstructuresin a wire-plateESP – laboratory Time-averaged flow streamlines in the ESP Vp = 0.9 m/s Flowstreamlines not much disturbedincomparisonwith no voltageflowstreamlines. Somedisturbances near theplateelectrodesinthedischarge region. Vp = 0.6 m/s Strongerdisturbancesthan for the Vp=0.9 m/s, vorticesinthedischarge region. Vp = 0.2 m/s Strongvorticesinthedischarge region. Pair of vorticesplaced 100 mm dowstreamthewireelectrodeblocktheflowinthe ESP ductcentre.

  10. LASER FLOW VISUALIZATION AND PIV IN ESP Study of the dust particle flow structures in 7-electrode wire ESP - laboratory Flow velocity field in the ESP model at a main flow velocity of 0.6 m/s. Positive polarity, voltage 24 kV.

  11. EHD FLOW PATTERNS IN A SPIKE-PLATE ESP UNDER POSITIVE AND NEGATIVE POLARITIES   Spikeelectrode: 12 spikes 200 mm long 1 mm thickness 14 measurementplanes: A, B, C - longitudinal E - N - transverse Primary flow velocity: 0.6 m/s (Reynolds number 4000) Flow gas: ambient air Dust: TiO2 particles (2D PIV) or cigarette smoke (3D PIV) Operating voltage: 0 – 28 kV (positive polarity) Discharge current: 0 – 210 mA (Ehd number up to 3 * 108)

  12. EHD FLOW PATTERNS IN A WIDE SPACINGSPIKE-PLATE ESP UNDER POSITIVE AND NEGATIVE POLARITIES   Side view V [m/s]

  13. EHD FLOW PATTERNS IN A SPIKE-PLATE ESP UNDER NEGATIVE POLARITY IMAGE OF THE PRECIPITATED DUST Dust 13

  14. EHD FLOW PATTERNS IN A SPIKE-PLATE ESP UNDER NEGATIVE POLARITY FLOW PATTERN AND IMAGE OF THE PRECIPITATED DUST Plane A U = -27.4 kV I = 260 mA Dust 14

  15. EHD FLOW PATTERNS IN A SPIKE-PLATE ESP UNDER POSITIVE POLARITY 3D PIV MEASUREMENT OF VELOCITY X-COMPONENT

  16. NARROWESPWITHLONGITUDINALWIREELECTRODE Front view Side view V [m/s]

  17. EHD GAS PUMP Flowgenerated by EHD gas pump PIV measurement EHD gas pump overview Y in mm X in mm Velocity profiles at the exit section of EHD gas pump Velocity profile at the exit of EHD gas pump (3D PIV) EHD gas pump features: • Air flow generated by DC corona discharge • Electrode configuration determines the flow direction • Flow velocity up to 1 m/s • Flow rate up to 630 cm3/s

  18. Time-averaged streamlines of a airflow induced by multi DBD actuator with floating saw-like interelectrodes Airflow velocity m/s Dielectric: glass plate – 2 mm thick High voltage: Upp = 32 kV, f = 1.5 kHz Length of HV and grounded electrodes: 50 mm Length of floating interelectrodes: 45 mm High voltage electrodes width: 15 mm HV and FL interelectrodes in optimum position Floating interelectrodes width: 3 mm Floatingto groundedelectrodedistance: 6 mm Groundedelectrodes width: 3 mm Grounded to floating electrode distance: 13 mm 18

  19. EXPERIMENT - CALCULATION Flowpatternsinwire-plate ESP for variousdustdensities Experiment Calculation – K. Adamiak & P. Atten

  20. EXPERIMENT - CALCULATION Flowpatternsinwire-plate ESP for variousEhd/Re2ratio Experiment Calculation – Chun & Chang Ehd/Re2 – a measure of the EHD disturbance of the primaryflow Ehd = I t* L3 / (A *r*ng2*mi)Re = U0* L / ng

  21. LASER FLOW VISUALIZATION IN INDUSTRIAL ESP

  22. LASER SYSTEM FOR FLOW VISUALIZATION ON THE TOP OF INDUSTRIAL ESP

  23. LASER FLOW VISUALIZATION IN INDUSTRIAL ESP All foursections ON, hammeringat t=0 insection 4 Yellow lines – flowstreamlines deducedfromtheflowimages Light-greenspots – dustinthe ESP

  24. CONCLUSIONS Laser visualization and Particle Image Velocimetry proved to be useful instruments in studying flow and collection phenomena in electrostatic precipitators Owing to the PIV measurement a correlation between structures of the particle flow and particle deposit in the spike-plate ESP was found. The particle flow structures explain how the particle deposit structures are formed. Basing on the PIV results we found a correlation between the particle flow structures and the total collection efficiency for the various configurations of spike-type electrode. Negative effect for downstream-directed one-sided electrode.

  25. COLLABORATORS Centre for Plasma and Laser Engineering Institute of Fluid Flow Machinery Polish Academy of Sciences, Gdańsk, Poland J. Mizeraczyk, J. Podliński, M. Kocik, M. Dors, J. Dekowski, A. Niewulis Department of Engineering Physics McMaster University, Hamilton, Ontario, Canada J.-S. Chang, D. Brocilo, K. Urashima, Y.N. Chun, A.A. Berezin Department of Electrical and Electronic Engineering Oita University, Japan T. Ohkubo, Y. Nomoto, S. Kanazawa Department of Ecological Engineering Toyohashi University of Technology, Japan A. Mizuno Laboratoire d'Electrostatique et de Matériaux Diélectriques Université Joseph Fourier, Grenoble, France P. Atten Laboratoire d’Etudes Aérodynamiques Université de Poitiers, France G. Touchard

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