Modelling of a post-discharge reactor used for plasma sterilization

• Type: Article in International Scientific Journal
• Date: 2006

Authors

Kutasi, K (Author) Other; Carlos Daniel Diogo Matias Pintassilgo (Author) FEUP; Coelho, PJ (Author) Other; Loureiro, J (Author) Other

Journal

Title: Journal of Physics D: Applied Physics

Vol. 39 No. 1

Pages: 3978-3988

ISSN: 0022-3727

Publisher: Institute of Physics Publishing

Indexing

ISI Web of Knowledge - 19 Citations

Scopus - 19 Citations

Other information

Authenticus ID: P-004-H5X

DOI: 10.1088/0022-3727/39/18/009

Abstract (EN): A three-dimensional hydrodynamic model is developed to simulate a post-discharge reactor placed downstream from a flowing microwave discharge in N-2-O-2 used for plasma sterilization. The temperature distribution and the density distributions of NO(B (2)Pi) molecules and O(P-3) atoms, which are known to play a central role in the sterilization process, are obtained in the reactor in the case of discharges at 915 and 2450 MHz, pressure range 1-8 Torr and N-2-xO(2) mixture composition, with x = 0.2-2%. Excluding the flow direction, sufficiently low temperatures ideal for sterilization have been found in most parts of the reactor. The highest NO(B) and O(P-3) concentrations at the reactor entrance are achieved at the highest pressure values investigated here. However, these larger densities rapidly decrease within a few centimetres below the values obtained at lower pressure. On the contrary, at low pressure the density distributions of NO(B) and O(P-3) are quasi-homogeneous in most of the horizontal planes. At 8 Torr the densities increase orders of magnitude in the reactor as the gas flow increases from 1 x 10(3) to 4 x 10(3) sccm, while at 2 Torr this increase does not reach even one order of magnitude. In agreement with the experiment, the densities of NO( B) and O(P-3) have been found to increase at 2 Torr as the O-2 percentage increases in the discharge gas mixture, whereas at 8 Torr the density of NO(B) decreases with O-2 percentage and the O(P-3) density presents only minor changes.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 11