Transportation of nitrogen atoms in an atmospheric pressure post-discharge of pure nitrogen

Abstract

In this paper, the transportation of nitrogen atoms in a flowing post-discharge of molecular nitrogen at atmospheric pressure is studied. The axial variation of the density of nitrogen atoms is modelled and compared with measurements. A relatively high initial density, i.e. several 1014 atoms/cm3, is obtained by this approach, showing also that the main losses are caused by volume and surface recombination during transportation. A low value is found for the recombination probability of the used polyamide surface (around some 10−4) allowing therefore quite long transportation times and distances.

Bacterial Decontamination of the Inner Wall of Narrow Tubes by a Nitrogen Afterglow at Atmospheric Pressure and its Relation to Local Atomic Nitrogen Concentration

“…It can be noted that, over long distances, the actual value of P 3 which is related to the wall material leads to an exponential decrease of [N] with z : A similar variation was obtained with 2D numerical modeling by Fromy …”

“…Previously, the pertinence of such a model was experimentally verified with a 40 SLM gas flow, i.e., twice the flow rate considered here. In order to study the effect of the flow change, the same experiment as in Fromy was made to measure [N] with the O 2 titration method. Besides published measurements at 40 and 45 SLM, Figure shows measured 1/[N] for varying flows between 20 and 45 SLM, as a function of ζ , ζ being proportional to axial transit time, with abscissa z as a parameter: ζ = { z – z D )/gas flow.…”

“…A 2D complete numerical simulation, as presented in Fromy, [17] is possible. Here, it is preferred to use an easier analytical resolution of a 1D simplified transport equation presented in Pointu, [14] which is reviewed in the following.…”

“…A similar variation was obtained with 2D numerical modeling by Fromy. [17] Except in the case where P 2 (z D ) is not negligible with respect to [N](z D ), possibly depending on gas velocity (z-z D )/ v thus appears to be the pertinent variable in Equation (14) for a given tube.…”

Nitrogen Atmospheric Pressure Post Discharges for Surface Biological Decontamination inside Small Diameter Tubes

“…In order to overcome the difficulty of unknown absolute sensitivity of the spectrometer device, [N] was measured with a new method using titration with O 2 ,9 and results have been compared to N transport modelling 10…”