Pulsed streamer discharge characteristics of ozone production in dry air

Abstract

Experimental investigation of HV short pulsed strcamcr discharges in dry air-fed ozonizers under various operating conditions arc reported. Ozone concentration, energy input and ozone production yield (efficiency) were measured at various voltagcs (14 to 37 kV), pulse repetition rates (25 to 400 pulses per second, pps), flow rales (1.5 to 3.0 llmin) and different gap spacings (10 to 20 mm) at a pressure of 1.01~10~ Pa in dry air. A spiral copper wire (1 m m in diamcler) madc to a cylindrical configuration (18 to 38 m m in diamcter) in a concentric coaxial clcckade system of various dimensions was employcd. A magnetic pulse comprcssor provided the H V and current pulses. Higher voltage and highcr repetition rates yielded higher concentrations of ozane at a fiwcd air flow rate. The present invcstigation was extended to assess the performance of this pulsed ozone generator using dry air under desired conditions of high concentration and high yield of ozone for industrial applications. ' Ucidcustia Corporation, 'lokyo, ]apau On Icavc from Universily of Windsor, Departnicnt of F.1cctrical and Cnnipiitcv h n ineering, Windsor, Ontario, Cauadn, hhnriscript was rcreived 011 11 Jrly 1999, in revisEd b m i a f

Ozone Generation by Pulsed Streamer Discharge in Air

“…With three oxygen atoms bonded together, it is a powerful but unstable oxidant, although having a half life of only between about 7 and 20 minutes. Nevertheless, when compared with alternatives such as the chlorination process (Samaranayake W., 2000;Buntat Z, 2003;Chalmers I D, 1994;, it offers a number of significant advantages, in particular its lower energy consumption (Samaranayake W., 2000;Buntat Z, 2003;Chalmers I D, 1994;Buntat Z, 2005;Chalmers I D, 1996;Samaranayake, 2001). As a consequence of its attractive properties, many methods of enhancing the production rate of ozone have been investigated.…”

“…The pulsed voltage applied throughout the present investigation was of positive rather than negative polarity, since it is known (Samaranayake, 2000;Samaranayake, p.849-854) that the streamers then produced have more branches and more channels per unit length, and are likely to lead to a greater dissociation of oxygen molecules. The pulse duration of 120 ns used in the experiments was sufficiently short not to accelerate significantly any ions, and as a result the chamber temperature remained at the ambient level (Tamaribuchi, 2007).…”

“…Ozone is produced during an electrical discharge at room temperature and pressure, with air assisting in the two main processes of dissociation and formation (Samaranayake, 2000). Initially, an oxygen atom is dissociated in collisions between high energy electrons and oxygen molecules (equations (1) and (2) below), before ozone itself is formed in a three-body reaction process (equation (3)).…”

“…Initially, an oxygen atom is dissociated in collisions between high energy electrons and oxygen molecules (equations (1) and (2) below), before ozone itself is formed in a three-body reaction process (equation (3)). M, the third particle involved in the collision process, could in dry air be either O 2 , O 3 or N 2 (Samaranayake, 2000;Simek, 2002 …”

Industrial Applications of Pulsed Power Technology

“…Nonthermal plasmas have many kinds of chemically activate radicals, such as O, O 3 , N, N * , N 2 + and OH, which are generated by the dissociation and ionization of the ambient gases caused by the impact of energetic electrons. Using pulsed power technology, nonthermal plasmas have been generated by a pulsed electron beam [29] or a pulsed streamer discharge [30], and have been used to treat nitric oxides (NO X ) [31][32][33][34], sulfur dioxide (SO 2 ) [35][36][37], carbon dioxide (CO 2 ) [38] and volatile organic compounds (VOCs) [39,40], and to generate ozone [41][42][43][44][45][46]. Particularly, the treatment of exhaust gases (NO X and SO 2 ) using a pulsed streamer discharge has been studied for the past decade.…”