Corona Emission and Ozone Production by Carbonized and Oxidized High-Voltage Wires

2006 ◽  
Vol 21 (3) ◽  
pp. 1636-1640 ◽  
Author(s):  
M.E.M. Horwitz ◽  
S.G. Horwitz ◽  
C.M. Horwitz
Author(s):  
Pitchasak CHANKUSON ◽  
Mudtorlep NISOA

An electric field in the dielectric barrier electrode system is necessary for ozone production because ozone is produced by the electric discharge of O2 under a high-intensity electric field. The gas discharge plasmas contain energetic particles, such as electrons, ions, atoms, and radicals. The recombination of the O atom and O2 in the plasma will form O3. In this paper, the dependence of DC electric field formation on electrode geometry and the gap between electrodes and dielectric materials were examined by using computational modeling. Thus, a set of electrode geometry, gap distance, and dielectric material were obtained for high-intensity and uniform electric field generation. The COMSOL Multiphysics software was used for the modeling. Among the electrode geometries of plate-plate, pin-plate and mesh-plate, the mesh-plate generated high-intensity and uniform electric field. In the modeling, dielectric materials, including quartz, mica, alumina, and water, were compared. The highest intensity of electric field occurred on the water surface. HIGHLIGHTS When the gap distance between two parallel electrodes is less than 100 mm, the electric field in the gap is constant, independent of the space A high-intensity and uniform electric field is generated in the gap between the dielectric and grounded electrodes when a fine mesh high-voltage electrode is utilized With the fine mesh electrode, the electric field is about two times higher than the conventional plate electrodes, whereas the electric field uniformity was about 90 %. Therefore the barrier discharge will be initiated with lower high voltage GRAPHICAL ABSTRACT


2005 ◽  
Vol 8 (2) ◽  
Author(s):  
Ryo Ono ◽  
Tetsuji Oda

AbstractThe energy efficiencies of ozone production by the primary and secondary streamers are studied in pulsed positive corona discharge. In a 20-kV dry air discharge, the two-dimensional distribution of ozone density shows that most of ozone is distributed in the secondary streamer channel, not in the primary one. It demonstrates that most of ozone is produced by the secondary streamer. However, the energies consumed by the primary and secondary streamers are estimated to be approximately equal in the 20-kV discharge. This result indicates that the energy efficiency of ozone production by the secondary streamer is much higher than that by the primary one. It is shown that high voltage operation is favorable for ozone production because the rise in voltage increases the ratio of energy consumed by the secondary streamer to that consumed by the primary one.


2019 ◽  
Vol 11 (3) ◽  
pp. 80-87
Author(s):  
Muhammad Ikhsan Sani

This paper presents an alternative solution for generating ozone using a low-cost automotive Capacitive Discharge Ignition (CDI) coil. High voltage ozone generating theory is implemented using a capacitive discharge circuit that uses ignition coil as its high voltage step-up transformer. A computer simulation has been performed to confirm the validity of the circuit function. By calculation and measurement, the coil has 196,71 voltage amplification factor. Furthermore, it has been implemented at a low frequency of about 10 - 40 Hz. Meanwhile, ozone output is measured using the colorimetric method. From a series of tests, that coil implementation has successfully generated a high voltage on ozone reactor tube at 31.47 kV voltages that essential for ozone production. Change of frequency will change the ozone concentration output linearly. The test was conducted using three different frequency: 10 Hz, 20 Hz, and 40 Hz. The result has shown that the highest ozone yield was 80 mg/hour.


Author(s):  
A. K. Sharma ◽  
D. M. Camaioni ◽  
G. B. Josephson ◽  
S. C. Goheen ◽  
G. M. Mong

AbstractOzone and nitric acid were formed when high voltage was applied across a metal (stainless steel) point and liquid (water) plane at atmospheric pressure and room temperature. Ozone was observed in the gas-phase and nitric acid in the liquid-phase. The gas-phase concentration of ozone reached a power-dependent steady-state whereas the nitric acid concentration in solution increased linearly with time. The rate of formation of ozone increased with increasing current. Aqueous solutions of potassium iodide were exposed to corona discharge to determine the amount of gas-phase ozone available to oxidize liquid-phase solutes. The result of the test with KI suggests that ozone is the major oxidant in the solution phase. An optimum point-to-plane distance of 1.5 cm was observed for both ozone production and solution phase oxidation. Corona discharge effectively destroyed both non-volatile organic compounds such as methylene blue and volatile compounds such as carbon tetrachloride in aqueous solutions.


Author(s):  
Chávez Velasco Iván Fabricio

The ozone is a gas composed by three molecules of oxygen which has a great oxidative capacity. This gas can be generated by a nucleus with two electrodes through high voltage in a phenomenon known as corona effect. Actually the conventional nucleus of ozone generators use plane electrodes with a dielectric in the middle of both. A nucleus composed by a mixed ionizador (coil and mesh) is presented as an alternative for an ozone machine in order to take advantage of the individual benefits of each electrode due to its shape and efficiency. A solenoid acts better without dielectric, reducing the consumption, and a mesh improves the air flux. As a result, there is a good production of ozone using this combination of electrodes. However, there are no studies that demonstrate that it is possible to use different types of electrodes in the same ionizador, for this reason in this study will be detected the production of ozone by corona effect in the proposed nucleus and will be approximated its concentration in a closed volume. Keywords: Ozone, corona effect, high voltage, generator, ionization. Resumen El ozono es un gas compuesto por tres moléculas de oxígeno que tiene una gran capacidad oxidativa. Este gas puede ser generado en un núcleo con dos electrodos mediante el uso de altos voltajes en un fenómeno conocido como efecto corona. Actualmente los núcleos de los generadores de ozono convencionales utilizan electrodos planos con un dieléctrico en medio de ellos. Un núcleo compuesto por un ionizador mixto (bobina y malla) se presenta como una alternativa para un ozonificador, con el fin de aprovechar las ventajas individuales de cada electrodo debido a su forma y eficiencia. Un solenoide actúa mejor sin dieléctrico, disminuyendo el consumo, y una malla mejora el flujo de aire. Lo que resulta en una buena producción de ozono utilizando esta combinación de electrodos. Sin embargo, no existen estudios anteriores que demuestran que se puede utilizar diferentes tipos de electrodos en un mismo ionizador, por esta razón en el presente estudio se detectará la producción de ozono por efecto corona en el núcleo mixto propuesto y aproximamos su concentración en un volumen cerrado. Palabras Clave: Ozono, efecto corona, alto voltaje, generador, ionización.


Author(s):  
L. D. Ackerman ◽  
S. H. Y. Wei

Mature human dental enamel has presented investigators with several difficulties in ultramicrotomy of specimens for electron microscopy due to its high degree of mineralization. This study explores the possibility of combining ion-milling and high voltage electron microscopy as a means of circumventing the problems of ultramicrotomy.A longitudinal section of an extracted human third molar was ground to a thickness of about 30 um and polarized light micrographs were taken. The specimen was attached to a single hole grid and thinned by argon-ion bombardment at 15° incidence while rotating at 15 rpm. The beam current in each of two guns was 50 μA with an accelerating voltage of 4 kV. A 20 nm carbon coating was evaporated onto the specimen to prevent an electron charge from building up during electron microscopy.


Author(s):  
Lee D. Peachey ◽  
Clara Franzini-Armstrong

The effective study of biological tissues in thick slices of embedded material by high voltage electron microscopy (HVEM) requires highly selective staining of those structures to be visualized so that they are not hidden or obscured by other structures in the image. A tilt pair of micrographs with subsequent stereoscopic viewing can be an important aid in three-dimensional visualization of these images, once an appropriate stain has been found. The peroxidase reaction has been used for this purpose in visualizing the T-system (transverse tubular system) of frog skeletal muscle by HVEM (1). We have found infiltration with lanthanum hydroxide to be particularly useful for three-dimensional visualization of certain aspects of the structure of the T- system in skeletal muscles of the frog. Specifically, lanthanum more completely fills the lumen of the tubules and is denser than the peroxidase reaction product.


Author(s):  
L. E. Thomas ◽  
J. S. Lally ◽  
R. M. Fisher

In addition to improved penetration at high voltage, the characteristics of HVEM images of crystalline materials are changed markedly as a result of many-beam excitation effects. This leads to changes in optimum imaging conditions for dislocations, planar faults, precipitates and other features.Resolution - Because of longer focal lengths and correspondingly larger aberrations, the usual instrument resolution parameter, CS174 λ 374 changes by only a factor of 2 from 100 kV to 1 MV. Since 90% of this change occurs below 500 kV any improvement in “classical” resolution in the MVEM is insignificant. However, as is widely recognized, an improvement in resolution for “thick” specimens (i.e. more than 1000 Å) due to reduced chromatic aberration is very large.


Author(s):  
T. Mukai ◽  
T. E. Mitchell

Radiation-induced homogeneous precipitation in Ni-Be alloys was recently observed by high voltage electron microscopy. A coupling of interstitial flux with solute Be atoms is responsible for the precipitation. The present investigation further shows that precipitation is also induced at thin foil surfaces by electron irradiation under a high vacuum.


Author(s):  
J. S. Lally ◽  
R. Evans

One of the instrumental factors often limiting the resolution of the electron microscope is image defocussing due to changes in accelerating voltage or objective lens current. This factor is particularly important in high voltage electron microscopes both because of the higher voltages and lens currents required but also because of the inherently longer focal lengths, i.e. 6 mm in contrast to 1.5-2.2 mm for modern short focal length objectives.The usual practice in commercial electron microscopes is to design separately stabilized accelerating voltage and lens supplies. In this case chromatic aberration in the image is caused by the random and independent fluctuations of both the high voltage and objective lens current.


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