A Vapor-Air Discharge with a Porous Electrolytic Cathode at Atmospheric Pressure

Abstract

An experimental investigation is performed for the first time of the structures and electrical and thermal characteristics of a vapor-air discharge between a porous (solid cylindrical body and hollow cylinder) electrolytic cathode and a solid anode in the range of current from 0.2 to 8 A with an interelectrode spacing of 2 to 200 mm for electrolytes of different compositions and concentrations with vertical and horizontal orientations of the plasma column in space at atmospheric pressure. An electrode of a new type is developed, namely, a porous electrolytic cathode (PEC), which makes it possible to produce cone-shaped, multichannel, and mixed discharges. The moist, boiling, and film modes of PEC operation are revealed. It is found that the heat loss on a PEC depends on the mode of its operation. The minimal heat loss is observed in the moist cathode mode, in which the electrolyte is delivered to the cathode working surface in the form of vapor only. In so doing, an almost complete regeneration occurs of heat delivered to the cathode from discharge plasma. It is found that the characteristics of a vapor-air discharge between a PEC and electrolytic anode depend significantly on the composition and concentration of the PEC electrolyte. The discharge voltage fluctuations and the nonuniform pattern of distribution of electric field intensity are revealed. The results of experimental investigation of a vapor-air discharge with a PEC are generalized in the form of an empirical formula.

Characterization of a DC-driven microplasma between a capillary tube and water surface

“…Several authors previously investigated discharge systems with electrolyte electrodes. These studies suggest that different modes, especially glow mode and multichannel mode could be ignited [11][12][13][14][15][16][17][18][19][20]. A mechanism of discharge maintenance based on the estimates of the average energy an impinging H + ion transfers to a negative ion of impurity in the electrolyte, was also proposed [11].…”

“…These studies suggest that different modes, especially glow mode and multichannel mode could be ignited [11][12][13][14][15][16][17][18][19][20]. A mechanism of discharge maintenance based on the estimates of the average energy an impinging H + ion transfers to a negative ion of impurity in the electrolyte, was also proposed [11]. Recently, several other groups developed a DC-driven microplasma with a hollow cathode and water anode for nanomaterial synthesis and engineering [4,6,28,29].…”

“…New chemical pathways that are not achievable with traditional plasma processes may be possible by microplasma-produced species at relatively low gas temperatures. Among all kinds of non-equilibrium plasma systems [7][8][9][10], underwater or on water discharges are interesting and promising for their value in plasma physics research [11][12][13][14][15][16][17][18][19][20][21][22][23] and applications in materials processing, biology, and water sterilization [5,[24][25][26]. A range of approaches for generating plasmas in/on liquids have been explored.…”

Characteristics of discharge with liquid non-metallic cathode burning in air flow

“…It is of interest to study similar discharges in an air flow. Plasmatrons with liquid cathodes and with both liquid electrodes have already been developed (for example [11,12]), but the properties of plasma generated by such discharges were not investigated until now. So, a comprehensive study is necessary.…”