The Experts below are selected from a list of 324 Experts worldwide ranked by ideXlab platform

Mounir Laroussi - One of the best experts on this subject based on the ideXlab platform.

  • the uniform steady state atmospheric pressure dc plasma
    IEEE Transactions on Plasma Science, 2002
    Co-Authors: I Alexeff, Mounir Laroussi
    Abstract:

    We have developed and tested a steady-state DC plasma Discharge apparatus that operates at atmospheric pressure. The important feature is a ceramic Discharge Electrode that prevents the diffuse Discharge from contracting into an arc. The apparatus has been used successfully in the destruction of microorganisms.

  • the uniform steady state atmospheric pressure dc plasma
    International Conference on Plasma Science, 2002
    Co-Authors: I Alexeff, Mounir Laroussi
    Abstract:

    Summary form only given, as follows. We have developed and diagnosed a steady-state DC plasma Discharge apparatus that operates at atmospheric pressure. The device also works well with low frequency AC at 60 Hz. The new feature is a ceramic Discharge Electrode that prevents the diffuse Discharge from contracting into an arc. The apparatus works well in air, but for large volume plasma generation of several liters, helium is used. The maximum DC power applied is 300 Watts. The apparatus has been used successfully in the destruction of microorganisms (1). Recent results from our plasma Discharge in helium include separate measurements of the electron and the ion densities. These numbers differ, as the plasma contains negative ions as well as electrons. The most convincing electron density measurement is a microwave attenuation measurement of 10 exp 11 per cc. Conventional plasma resonance measurements do not work, as the high electron-gas atom collision rate suppresses the resonance effects. Although the attenuation is small-about one percent-the attenuation is readily observable by a chopping technique. As a byproduct of the density measurement, the lifetime of the free electrons before being converted into negative ions is observed to be tens of microseconds. A second plasma electron density measurement is made by measuring the electron drift current, which also yields 10 exp 11 per cc. Plasma ion density measurements have been made with a variety of single and double Langmuir probes, and yield densities on the order of 10 exp 12 per cc.

Jerzy Mizeraczyk - One of the best experts on this subject based on the ideXlab platform.

  • Collection efficiency in narrow electrostatic precipitators with a longitudinal or transverse wire Electrode
    IEEE Transactions on Dielectrics and Electrical Insulation, 2011
    Co-Authors: A. Niewulis, V. Shapoval, Janusz Podlinski, Jerzy Mizeraczyk
    Abstract:

    Recently narrow electrostatic precipitators (ESPs) have become a subject of interest because of their possible application in diesel engine exhaust systems. In this work, results of particle collection efficiency measurements in narrow electrostatic precipitators for negative and positive dc voltage polarity are presented. The ESP used in this work was a parallelepiped equipped with wire Discharge Electrode and two collecting plate-Electrodes. The experiments were carried out for two Discharge Electrode positions: longitudinally or transversely to the main flow direction. The obtained results showed that the collection efficiency strongly depends on the Discharge Electrode position. It is higher in the ESP with longitudinally-to-flow placed Discharge Electrode. The collection efficiency is also influenced by the EHD secondary flow generated in the ESP. The EHD secondary flow with high migration velocity (y-component of the particle velocity) and low turbulence intensity increase the chance of the particle deposition on the collecting Electrodes.

  • Electrohydrodynamic flow in a wire-plate non-thermal plasma reactor measured by 3D PIV method
    The European Physical Journal D, 2009
    Co-Authors: Janusz Podlinski, A. Niewulis, Jerzy Mizeraczyk
    Abstract:

    This work was aimed at measurements of the electrohydrodynamic (EHD) secondary flow in a non-thermal plasma reactor using three-dimensional particle image velocimetry (3D PIV) method. The wide-type non-thermal plasma reactor used in this work was an acrylic box with a wire Discharge Electrode and two plate collecting Electrodes. The positive DC voltage was applied to the wire Electrode through a 10 MΩ resistor. The collecting Electrodes were grounded. The voltage applied to the wire Electrode was 28 kV. Air flow seeded with a cigarette smoke was blown along the reactor duct with an average velocity of 0.6 m/s. The 3D PIV velocity fields measurements were carried out in four parallel planes stretched along the reactor duct, perpendicularly to the wire Electrode and plate Electrodes. The measured flow velocity fields illustrate complex nature of the EHD induced secondary flow in the non-thermal plasma reactor.

  • Electrode geometry effects on the collection efficiency of submicron and ultra fine dust particles in spike plate electrostatic precipitators
    Journal of Physics: Conference Series, 2008
    Co-Authors: D. Brocilo, Janusz Podlinski, Jerzy Mizeraczyk, Jenshih Chang, R.d. Findlay
    Abstract:

    The collection efficiency of electrostatic precipitators for the submicron particles ranging from 0.1 to 1 m and ultrafine particles smaller than 0.1m is below the requirements of new PM2.5 emission regulations. In this work, numerical and experimental studies were conducted to examine the effect of Discharge and collecting Electrode geometries on the ion density and electric field profiles and consequently their effect on the particle surface charge and collection efficiency. The collection efficiency prediction was based on a modified Deutsche's equation after calculation of three dimensional electric field and ion density profiles. Whereas, the particle surface charge was obtained from diffusion and field charging models. Results show that the collection efficiency of fine particles for the spike-type Discharge Electrode when compared to the conventional wire-type was improved. Experimental validations were conducted on a bench scale electrostatic precipitator for total and partial collection efficiency of particles ranging in size from 0.01 to 20 m and the results indicated that the model can be effectively applied for prototype design, modification, and scale-up of collecting and Discharge Electrodes.

  • Instantaneous and time-averaged velocity fields in a wide electrostatic precipitator
    2008
    Co-Authors: Janusz Podlinski, Pierre Atten, Jerzy Mizeraczyk
    Abstract:

    This work was aimed at clarifying whether the electrohydrodynamic (EHD) flow in a relatively wide electrostatic precipitator (ESP) (width:height = 2) is 2- or 3- dimensional (3D). The previous our measurements of 3D timeaveraged flow velocity fields suggested that the flow in the ESP duct centre is almost 2-dimensional. In this paper we present both the 3D instantaneous and time-averaged flow velocity fields in a relatively wide ESP (width:height = 2). The ESP used in this work was an acrylic parallelepiped with a negatively polarized wire Discharge Electrode and two plate collecting Electrodes. The velocity field was measured using Particle Image Velocimetry in the observation midplane along the ESP.

  • ESP performance for various dust densities
    Journal of Electrostatics, 2008
    Co-Authors: Janusz Podlinski, A. Niewulis, Jerzy Mizeraczyk, Pierre Atten
    Abstract:

    In this paper, results of Particle Image Velocimetry (PIV) measurements of the electrohydrodynamic (EHD) flow velocity fields in an electrostatic precipitator (ESP) are presented. The measurements were carried out for various densities of submicron dust. The ESP was an acrylic parallelepiped with a wire Discharge Electrode and two plate collecting Electrodes. The positive DC voltage was applied to the wire Electrode, placed perpendicularly to the main gas flow. The PIV measurements were carried out in a plane placed perpendicularly to the wire Electrode at its half-length. The obtained results show that the general shape of the flow patterns at different dust densities is similar in the bulk of the flow. However, the flow velocity and the level of its turbulence strongly depend on the dust density, in particular in the region around the wire Electrode.

I Alexeff - One of the best experts on this subject based on the ideXlab platform.

  • the uniform steady state atmospheric pressure dc plasma
    IEEE Transactions on Plasma Science, 2002
    Co-Authors: I Alexeff, Mounir Laroussi
    Abstract:

    We have developed and tested a steady-state DC plasma Discharge apparatus that operates at atmospheric pressure. The important feature is a ceramic Discharge Electrode that prevents the diffuse Discharge from contracting into an arc. The apparatus has been used successfully in the destruction of microorganisms.

  • the uniform steady state atmospheric pressure dc plasma
    International Conference on Plasma Science, 2002
    Co-Authors: I Alexeff, Mounir Laroussi
    Abstract:

    Summary form only given, as follows. We have developed and diagnosed a steady-state DC plasma Discharge apparatus that operates at atmospheric pressure. The device also works well with low frequency AC at 60 Hz. The new feature is a ceramic Discharge Electrode that prevents the diffuse Discharge from contracting into an arc. The apparatus works well in air, but for large volume plasma generation of several liters, helium is used. The maximum DC power applied is 300 Watts. The apparatus has been used successfully in the destruction of microorganisms (1). Recent results from our plasma Discharge in helium include separate measurements of the electron and the ion densities. These numbers differ, as the plasma contains negative ions as well as electrons. The most convincing electron density measurement is a microwave attenuation measurement of 10 exp 11 per cc. Conventional plasma resonance measurements do not work, as the high electron-gas atom collision rate suppresses the resonance effects. Although the attenuation is small-about one percent-the attenuation is readily observable by a chopping technique. As a byproduct of the density measurement, the lifetime of the free electrons before being converted into negative ions is observed to be tens of microseconds. A second plasma electron density measurement is made by measuring the electron drift current, which also yields 10 exp 11 per cc. Plasma ion density measurements have been made with a variety of single and double Langmuir probes, and yield densities on the order of 10 exp 12 per cc.

Janusz Podlinski - One of the best experts on this subject based on the ideXlab platform.

  • Collection efficiency in narrow electrostatic precipitators with a longitudinal or transverse wire Electrode
    IEEE Transactions on Dielectrics and Electrical Insulation, 2011
    Co-Authors: A. Niewulis, V. Shapoval, Janusz Podlinski, Jerzy Mizeraczyk
    Abstract:

    Recently narrow electrostatic precipitators (ESPs) have become a subject of interest because of their possible application in diesel engine exhaust systems. In this work, results of particle collection efficiency measurements in narrow electrostatic precipitators for negative and positive dc voltage polarity are presented. The ESP used in this work was a parallelepiped equipped with wire Discharge Electrode and two collecting plate-Electrodes. The experiments were carried out for two Discharge Electrode positions: longitudinally or transversely to the main flow direction. The obtained results showed that the collection efficiency strongly depends on the Discharge Electrode position. It is higher in the ESP with longitudinally-to-flow placed Discharge Electrode. The collection efficiency is also influenced by the EHD secondary flow generated in the ESP. The EHD secondary flow with high migration velocity (y-component of the particle velocity) and low turbulence intensity increase the chance of the particle deposition on the collecting Electrodes.

  • Electrohydrodynamic flow in a wire-plate non-thermal plasma reactor measured by 3D PIV method
    The European Physical Journal D, 2009
    Co-Authors: Janusz Podlinski, A. Niewulis, Jerzy Mizeraczyk
    Abstract:

    This work was aimed at measurements of the electrohydrodynamic (EHD) secondary flow in a non-thermal plasma reactor using three-dimensional particle image velocimetry (3D PIV) method. The wide-type non-thermal plasma reactor used in this work was an acrylic box with a wire Discharge Electrode and two plate collecting Electrodes. The positive DC voltage was applied to the wire Electrode through a 10 MΩ resistor. The collecting Electrodes were grounded. The voltage applied to the wire Electrode was 28 kV. Air flow seeded with a cigarette smoke was blown along the reactor duct with an average velocity of 0.6 m/s. The 3D PIV velocity fields measurements were carried out in four parallel planes stretched along the reactor duct, perpendicularly to the wire Electrode and plate Electrodes. The measured flow velocity fields illustrate complex nature of the EHD induced secondary flow in the non-thermal plasma reactor.

  • Electrode geometry effects on the collection efficiency of submicron and ultra fine dust particles in spike plate electrostatic precipitators
    Journal of Physics: Conference Series, 2008
    Co-Authors: D. Brocilo, Janusz Podlinski, Jerzy Mizeraczyk, Jenshih Chang, R.d. Findlay
    Abstract:

    The collection efficiency of electrostatic precipitators for the submicron particles ranging from 0.1 to 1 m and ultrafine particles smaller than 0.1m is below the requirements of new PM2.5 emission regulations. In this work, numerical and experimental studies were conducted to examine the effect of Discharge and collecting Electrode geometries on the ion density and electric field profiles and consequently their effect on the particle surface charge and collection efficiency. The collection efficiency prediction was based on a modified Deutsche's equation after calculation of three dimensional electric field and ion density profiles. Whereas, the particle surface charge was obtained from diffusion and field charging models. Results show that the collection efficiency of fine particles for the spike-type Discharge Electrode when compared to the conventional wire-type was improved. Experimental validations were conducted on a bench scale electrostatic precipitator for total and partial collection efficiency of particles ranging in size from 0.01 to 20 m and the results indicated that the model can be effectively applied for prototype design, modification, and scale-up of collecting and Discharge Electrodes.

  • Instantaneous and time-averaged velocity fields in a wide electrostatic precipitator
    2008
    Co-Authors: Janusz Podlinski, Pierre Atten, Jerzy Mizeraczyk
    Abstract:

    This work was aimed at clarifying whether the electrohydrodynamic (EHD) flow in a relatively wide electrostatic precipitator (ESP) (width:height = 2) is 2- or 3- dimensional (3D). The previous our measurements of 3D timeaveraged flow velocity fields suggested that the flow in the ESP duct centre is almost 2-dimensional. In this paper we present both the 3D instantaneous and time-averaged flow velocity fields in a relatively wide ESP (width:height = 2). The ESP used in this work was an acrylic parallelepiped with a negatively polarized wire Discharge Electrode and two plate collecting Electrodes. The velocity field was measured using Particle Image Velocimetry in the observation midplane along the ESP.

  • ESP performance for various dust densities
    Journal of Electrostatics, 2008
    Co-Authors: Janusz Podlinski, A. Niewulis, Jerzy Mizeraczyk, Pierre Atten
    Abstract:

    In this paper, results of Particle Image Velocimetry (PIV) measurements of the electrohydrodynamic (EHD) flow velocity fields in an electrostatic precipitator (ESP) are presented. The measurements were carried out for various densities of submicron dust. The ESP was an acrylic parallelepiped with a wire Discharge Electrode and two plate collecting Electrodes. The positive DC voltage was applied to the wire Electrode, placed perpendicularly to the main gas flow. The PIV measurements were carried out in a plane placed perpendicularly to the wire Electrode at its half-length. The obtained results show that the general shape of the flow patterns at different dust densities is similar in the bulk of the flow. However, the flow velocity and the level of its turbulence strongly depend on the dust density, in particular in the region around the wire Electrode.

J.s. Chang - One of the best experts on this subject based on the ideXlab platform.

  • Measurement of flow velocity field in corona Discharge radical shower non-thermal plasma reactor
    Czechoslovak Journal of Physics, 2004
    Co-Authors: J. Dekowski, Jerzy Mizeraczyk, Toshikazu Ohkubo, Seiji Kanazawa, J.s. Chang
    Abstract:

    In this paper results of the Particle Image Velocimetry (PIV) measurements of the flow velocity fields in a corona Discharge radical shower (CDRS) non-thermal plasma reactor are presented. The Discharge Electrode of the CDRS reactor was a thin tube with several nozzles, through which a gas mixture was added to the reactor. The velocity fields were measured in two flow planes perpendicular to the Electrode tube: the first plane was set between two nozzles in the middle of the Discharge Electrode, and the second passed through one of them. In both planes electrohydrodynamically generated vortexes were found. However, in the plane set between the two nozzles, the vortexes were smaller. This investigation shows that in the reactor with the CDRS Discharge Electrode is used, the vortexes revolve in the opposite direction to those generated in the non-thermal plasma reactors with smooth wire Discharge Electrodes. The flow patterns in the reactor with CDRS Electrode are more stable than those with the smooth wire Electrode. This can have an influence on the performance of the CDRS reactors.

  • Light emission from the surface of spike-type Discharge Electrode at negative corona Discharge in a non-thermal plasma reactor
    The 30th International Conference on Plasma Science 2003. ICOPS 2003. IEEE Conference Record - Abstracts., 2003
    Co-Authors: D. Brocilo, J.s. Chang, R.d. Findlay
    Abstract:

    Summary form only given, as follows. In the past, many experimental investigations for glow or streamer corona induced plasma were conducted by digital real-time or high frame-rate CCD cameras. For example, the light emission profiles at the surface of the spike-type Discharge Electrode were changing from mono to dual distribution with increasing applied voltage.

  • Modelling of the effect of Electrode geometries on the corona Discharge current-voltage characteristic for wire-plate electrostatic precipitators
    2001 Annual Report Conference on Electrical Insulation and Dielectric Phenomena (Cat. No.01CH37225), 2001
    Co-Authors: D. Brocilo, J.s. Chang, R.d. Findlay, Y. Kawada
    Abstract:

    An electrostatic precipitator (ESP) operates on the principle of electrostatic separation of dust particles after charging, hence high ion density and electric fields are required. Therefore, the corona Discharge current-voltage characteristic is very important and depends on several factors: Discharge Electrode shape, dimensions and surface condition, gas flow properties, dust particle loading and space charge, polarity of applied voltage, etc. We present a model for the prediction of the current-voltage characteristic and experimentally validate it for round, threaded, rectangular and rigid Discharge Electrodes in combination with plate type collecting Electrodes. The experimental validation shows good agreement for the case of the round Discharge Electrode. The model predicts the effect of wire diameter, plate length and gas flow temperature. For the rigid Discharge Electrode, of the same Electrode thickness as the diameter of the round Electrode, much lower corona onset voltage was observed.