Gliding arc

Simplified schematics of a gliding arc-type plasma reformer. 1 = Electrodes, 2 = discharges, 3 = vessel with insulation, and 4 = electrode connectors. 

Gliding arc discharge This is a combination of high-power equilibrium arc discharge and better selectivity of nonthermal plasmas. It has also been reported to be used for the utilization of greenhouse gases such as CH4 and/or C02 [9-13],... 

Figure 1—8. Gliding arc discharge stabilized in the reverse vortex ( tornado ) gas flow.

A gliding arc is an auto-oscillating periodic discharge between at least two diverging electrodes submerged in gas flow (Fig. 4-51). Self-initiated in the upstream narrowest gap, the... 

The gliding arc has been known for more than one hundred years in the form of Jacob s ladder and was first used for producing nitrogen-based fertilizers by Naville and Guye (1904). Recent contributions to the development of gliding arcs have been made by A. 

Figure 4-51. Gliding arc discharge (a) general sehematie of flat eonflguration (b) photo of the discharge in flat configuration.

Figure 4-52. Gliding arc evolution with transition from quasi-thermal to non-thermal regime of the discharge series of consequent snapshots.

Figure 4-53. Conventional electric circuit schematic for the gliding arc discharg...

Figure 4-54. Consequent phases of evolution of a gliding arc discharge (A) region of gas breakdown (B) quasiequilibrium plasma phase (C) non-equilibrium plasma phase.

Figure 4-55. Evolution of current, voltage, and power with increasing length of the gliding arc discharge.

Equilibrium Phase of Gliding Arc, Its Critical Parameters, and Fast Equilibrium-to-Non-Equilibrium Transition... 

Gliding Arc Stability Analysis and Transitional and Non-Equilibrium Phases of the Discharge... 

When the electric field is high, the gliding arc conductivity a(To,E) depends not only on gas temperature, as in quasi-equilibrium plasma, but also on the field E. The logarithmic sensitivity of the electric conductivity to the gas temperature corresponds to the quasiequilibrium Saha ionization ... 

Table 4-10. Critical Gliding Arc Parameters Before Fast Equilibrium-to-Non-Equilibrium Transition as Function of Initial Current 7o...

After the fast transition, the gliding arc continues to evolve under the non-equihbrium conditions Te To (Rusanov et al., 1993 Keimedy et al., 1997). Up to 70-80% of the total power can be dissipated in the non-equihbrium plasma phase with Te 1 eV and... 

Figure 4-56. General schematic of a gliding arc discharge in a fluidized bed.

Figure 4-57. Non-equilibrium gliding arc discharge rotating in magnetic field pictures made with different exposure times.

I. Special Configurations of Gliding Arc Discharges Gliding Arc Stabilized in Reverse Vortex (Tornado) Flow... 

Interesting for applications is gliding arc stabilization in the reverse vortex (tornado) flow. This approach is opposite that of the conventional forward-vortex stabilization (Fig. 4-59a), where the swirl generator is placed upstream with respect to discharge and the rotating gas provides the walls with protection from the heat flux (Gutsol, 1997). Reverse... 

Figure 4-60. Non-equilibrium gliding arc discharge moving along a spiral eleetrode and stabilized in the reverse vortex (tornado) flow.

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