Enhancement of the absorption capacity of soot by the action of direct-current corona electric field on hydrocarbon flame

Mechanisms of air breakdowns for aluminum conductors steel reinforced wire-wire gaps induced by propane jet flames

“…Meanwhile, in the electric field, soot particles grow from disorder to high crystallization, and the top of a crystallization block or a soot chain is prominent. This is conducive to inducing the distortion of an electric field and promoting a discharge (Shvedchikov et al, 2010). However, the arc with a high temperature bridges the soot particles, ignites the soot particles very easily, makes them change into gas products through burning and disappear at last.…”

“…The practical insulation air gap becomes shorter and the thermal effects (Figure 6B) of the flame accelerate the movement of ions (ion wind, Figure 6B) between the wires. As a result, the wire-wire gap is easier to be broken down (Shvedchikov et al, 2010). The voltage suddenly decreases when the gap (10.0 cm) breaks down and the arc appears Note: "-" symbol means that the breakdown voltage exceeds the maximum voltage that the device can reach, therefore the breakdown discharge cannot occur under this condition.…”

“…In addition, under gas flow rates of 6 L/min and 12 L/min, the average breakdown field strengths both show increasing trends from continuous zone 1 to the intermittent zone, indicating that fire source power (heat release rate of a propane flame), temperature, heat exchange (thermal buoyancy and convection), soot particle, ion wind and polarity effect have obvious effects on a wire-wire gap breakdown (Rickard et al, 2005;Shvedchikov et al, 2010;Borgatelli and Dunn-Rankin, 2012). Different from the above characteristic is that when the gas flow rate is 18 L/min, average breakdown field strengths of three flame zones show little differences.…”

“…The reason is that in this case, primarily due to the large initial jet momentum, the flame can maintain a long distance (stroke) without dispersing under the blowing force and inertia effect, the width and height of the flame are larger (HySafe, 2008). Comprehensive effects of fire source power, temperature, heat exchange, soot particle, ion wind and polarity (Rickard et al, 2005;Shvedchikov et al, 2010;Borgatelli and Dunn-Rankin, 2012) in the intermittent zone can still be maintained. Therefore, the wire-wire gaps can be bridged.…”