Neutralization of a spray of electrically charged droplets by a corona discharge

2016 ◽  
Vol 801 ◽  
pp. 130-149 ◽  
Author(s):  
F. J. Higuera
Keyword(s):  
Electric Field ◽  
Corona Discharge ◽  
Opposite Polarity ◽  
Forced Flow ◽  
Lagrangian Description ◽  
Charged Droplets ◽  
Corona Current ◽  
Current Voltage ◽  
Eulerian Descriptions ◽  
Electrically Charged

The neutralization of a dilute spray of electrically charged droplets by ions of the opposite polarity generated by a corona discharge at a wire ring is analysed numerically. A Lagrangian description of the spray and Eulerian descriptions of the gas and the ions are used to deal with this two-way coupled problem. A model of the corona consisting of a line of charge and a distribution of ion sources is proposed. In the configuration that is analysed, neutralization usually begins at the shroud of the spray and extends to inner regions when the corona current increases. The number density of droplets is large at the shroud due to neutralized droplets that are no longer pushed by the electric field. These droplets can be dragged towards a collector surface by a weak forced flow that overcomes the ionic wind due to the force of the ions on the gas. The fraction of the spray charge that is neutralized increases with the corona current, but the value of this current required for full neutralization is several times larger than the inlet electric current of the spray owing to loss of ions to the boundaries of the system. The electric field induced by the charge of the droplets opposes the field due to the voltage applied between the wire ring and the extractor through which the droplets are injected, and thus reduces the threshold voltage of the corona and significantly affects its current–voltage characteristic, which may become multivalued. In turn, the electric field due to the applied voltage and the space charge of the ions affects the shape of the spray and the velocity of the droplets.

Research on Corona Wire Application for High Dust Load ESP of Cement Kiln

2011 ◽  
Vol 228-229 ◽  
pp. 1070-1074
Author(s):  
Zhen Biao Liu ◽  
Li Zhong Xu ◽  
Xiang Sheng Guo
Keyword(s):  
Electric Field ◽  
Corona Discharge ◽  
Load Application ◽  
Cement Kiln ◽  
Electric Intensity ◽  
Electric Wind ◽  
Corona Current ◽  
Set Up ◽  
Dust Load ◽  
High Dust

Electronic corona may be obturated when dust load at inlet of ESP is more than 500g/Nm3, it will influence dedusting efficiency. Through analysis on current and electric intensity, we set up experiment device and use WS corona wire, fishbone corona wire, long dentation corona wire, V15 wire and RS corona wire to test their volt-ampere characteristics. This experiment indicates that the corona current produced by V15 and long dentation corona wires is higher, i.e. we can get higher corona current under same voltage to produce stronger corona discharge and electric wind, and it has little possibility to occur corona obturation in electric field. We can get the conclusion that V-typed corona wire is more suitable and economic for high dust load application.

scholarly journals Improvement of Corona Discharge Model and Its Application on Simulating Corona Discharge in the Presence of Wind

2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Xiufeng Guo ◽  
Qilin Zhang ◽  
Jinbo Zhang
Keyword(s):  
Wind Speed ◽  
Electric Field ◽  
Corona Discharge ◽  
Wind Direction ◽  
Driving Force ◽  
Horizontal Wind ◽  
Wind Component ◽  
Two Dimensional ◽  
Corona Current ◽  
Discharge Model

To evaluate the effect of wind on corona discharges occurring on the tip of a grounded rod during a negative charging process of thundercloud, a two-dimensional numerical model has been improved by considering the wind velocity as a driving force for the movement of the corona charges. It was found that not only wind speed but also wind direction have a significant effect on the distribution of corona charges, the local electric field around the rod, and the corona current. (1) Under the same wind speed, a larger horizontal wind can result in less accumulation of corona charges, a larger electric field, and a larger corona current. However, when the speed is less than 5 m s−1, the effect of wind direction on the corona current was weak. (2) Under the same wind direction, a larger wind speed can cause a larger corona current. However, when the horizontal wind component is smaller than the vertical, the larger wind speed would cause a smaller electric field. Thus, it is necessary to take the effects of the wind direction into consideration, rather than to consider its speed only, when studying the corona discharge and its effects on the upward leader.

scholarly journals Spectroscopic analysis of high electric field enhanced ionization in laser filaments in air for corona guiding

2016 ◽  
Vol 4 ◽  
Author(s):  
Yingxia Wei ◽  
Yaoxiang Liu ◽  
Tie-Jun Wang ◽  
Na Chen ◽  
Jingjing Ju ◽  
...  
Keyword(s):  
Experimental Study ◽  
Femtosecond Laser ◽  
Electric Field ◽  
Corona Discharge ◽  
High Voltage ◽  
Fluorescence Spectra ◽  
Spectroscopic Analysis ◽  
Laser Pulses ◽  
Spectroscopic Measurement ◽  
High Electric Field

We report on a systematic experimental study on the fluorescence spectra produced from a femtosecond laser filament in air under a high electric field. The electric field alone was strong enough to create corona discharge (CD). Fluorescence spectra from neutral and ionic air molecules were measured and compared with pure high-voltage CD and pure laser filamentation (FIL). Among them, high electric field assisted laser FIL produced nitrogen fluorescence more efficiently than either pure CD or pure FIL processes. The nonlinear enhancement of fluorescence from the interaction of the laser filament and corona discharging electric field resulted in a more efficient ionization along the laser filament zone, which was confirmed by the spectroscopic measurement of both ionization-induced fluorescence and plasma-scattered 800 nm laser pulses. This is believed to be the key precursor process for filament-guided discharge.

scholarly journals Charging of Piezoelectric Cellular Polypropylene Film by Means of a Series Dielectric Layer

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 333
Author(s):  
Pedro Llovera-Segovia ◽  
Gustavo Ortega-Braña ◽  
Vicente Fuster-Roig ◽  
Alfredo Quijano-López
Keyword(s):  
Electric Field ◽  
Corona Discharge ◽  
Dielectric Layer ◽  
Dielectric Breakdown ◽  
Piezoelectric Materials ◽  
High Resistivity ◽  
Internal Electric Field ◽  
Dielectric Polarization ◽  
Surface Flashover ◽  
In Series

Piezoelectric polymer cellular films have been developed and improved in the past decades. These piezoelectric materials are based on the polarization of the internal cells by means of induced discharges in the gas inside the cells. Internal discharges are driven by an external applied electric field. With this polarization method, cellular polypropylene (PP) polymers exhibit a high piezoelectric coefficient d33 and have been investigated because of their low dielectric polarization, high resistivity, and flexibility. Charging polymers foams is normally obtained by applying a corona discharge to the surface with a single tip electrode-plane arrangement or a triode electrode, which consists of a tip electrode-plane structure with a controlled potential intermediate mesh. Corona charging allows the surface potential of the sample to rise without breakdown or surface flashover. A charging method has been developed without corona discharge, and this has provided good results. In our work, a method has been developed to polarize polypropylene foams by applying an insulated high-voltage electrode on the surface of the sample. The dielectric layer in series with the sample allows for a high internal electric field to be reached in the sample but avoids dielectric breakdown of the sample. The distribution of the electric field between the sample and the dielectric barrier has been calculated. Experimental results with three different electrodes present good outcome in agreement with the calculations. High d33 constants of about 880 pC/N have been obtained. Mapping of the d33 constant on the surface has also been carried out showing good homogeneity on the area under the electrode.

scholarly journals Influence of a Point-to-Plane DC Negative Corona Discharge on Gel Surfaces

10.14311/1033 ◽  
2008 ◽  
Vol 48 (4) ◽  
Author(s):  
Y. Klenko ◽  
V. Scholtz
Keyword(s):  
Experimental Investigation ◽  
Surface Modification ◽  
Electric Field ◽  
Corona Discharge ◽  
Biomedical Applications ◽  
Single Point ◽  
Polymer Surfaces ◽  
Negative Corona ◽  
Negative Corona Discharge ◽  
Time Periods

Point-to-plane corona discharge is widely used for modifying polymer surfaces for biomedical applications and for sterilization and decontamination. This paper focuses on an experimental investigation of the influence of the single-point and multi-point corona discharge electric field on gel surface. Three types of gelatinous agar were used as the gel medium: blood agar, nutrient agar and Endo agar. The gel surface modification was studied for various time periods and discharge currents. 

Radial component of vortex electric field force

2021 ◽  
Vol 11 (1) ◽  
pp. 32-35
Author(s):  
Vasyl Tchaban ◽  
Keyword(s):  
Electric Field ◽  
Equations Of Motion ◽  
Spherical Body ◽  
Radial Component ◽  
Force Interaction ◽  
Finite Speed ◽  
The Third ◽  
Electric Field Force ◽  
Electrically Charged ◽  
Positively Charged

he differential equations of motion of electrically charged bodies in an uneven vortex electric field at all possible range of velocities are obtained in the article. In the force interaction, in addition to the two components – the Coulomb and Lorentz forces – the third component of a hitherto unknown force is involved. This component turned out to play a crucial role in the dynamics of movement. The equations are written in the usual 3D Euclidean space and physical time.This takes into account the finite speed of electric field propagation and the law of electric charge conservation. On this basis, the trajectory of the electron in an uneven electric field generated by a positively charged spherical body is simulated. The equations of motion are written in vector and coordinate forms. A physical interpretation of the obtained mathematical results is given. Examples of simulations are given.

Anomalous change of carrier transport property of ferroelectric Hf0.5Zr0.5O2 thin films in the first poling treatment

2022 ◽  
Author(s):  
Yukinori Morita ◽  
Hiroyuki OTA ◽  
Shinji MIGITA
Keyword(s):  
Thin Films ◽  
Electric Field ◽  
Transport Property ◽  
Carrier Transport ◽  
Current Flow ◽  
Discontinuity Point ◽  
Voltage Sweep ◽  
Current Voltage ◽  
Carrier Transport Property ◽  
Carrier Transport Properties

Abstract Carrier transport properties of ferroelectric Hf0.5Zr0.5O2 (HZO) thin films have been investigated on metal-ferroelectric-metal (MFM) capacitor in the first current flow of ferroelectric poling treatment. In current–voltage (I–V) measurement of MFM capacitor, a kink or discontinuity point of derivative in I–V characteristic appears, and after the cyclic voltage sweep this kink disappears. This phenomenon is different from the ferroelectric instabilities after several thousand or million voltage cycle applies reported as the wake-up and fatigue. From the analysis using Poole-Frenkel plot of I–V characteristics, it is suggested that irreversible trap generation by electric field apply occurs in poling treatment.

scholarly journals Statistical Study on Space Charge effects and Stage Characteristics of Needle-Plate Corona Discharge under DC Voltage

Energies ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2732 ◽  
Author(s):  
Disheng Wang ◽  
Lin Du ◽  
Chenguo Yao
Keyword(s):  
Electric Field ◽  
Space Charge ◽  
Corona Discharge ◽  
Discharge Process ◽  
Space Charge Effects ◽  
Discharge Characteristics ◽  
Charge Effects ◽  
Dc Voltage ◽  
Field Distributions ◽  
Space Charges

The air’s partial discharges (PD) under DC voltage are obviously affected by space charges. Discharge pulse parameters have statistical regularity, which can be applied to analyze the space charge effects and discharge characteristics during the discharge process. Paper studies air corona discharge under DC voltage with needle-plate model. Statistical rules of repetition rate (n), amplitude (V) and interval time (∆t) are extracted, and corresponding space charge effects and electric field distributions in PD process are analyzed. The discharge stages of corona discharge under DC voltage are divided. Furthermore, reflected space charge effects, electric field distributions and discharge characteristics of each stages are summarized to better explain the stage discharge mechanism. This research verifies that microcosmic process of PD under DC voltage can be described based on statistical method. It contributes to the microcosmic illustration of gas PD with space charges.

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