Plasma Chemistry and Plasma Processing, Vol. 19, No. 1, 1999 Influence of the Electromagnetic Forces on Momentum and Heat Transfer in a 3-Phase ac Plasma Reactor Benjamin Ravary, 1  Laurent Fulcheri, 1 Jon Arne Bakken, 2  Gilles Flamant, 3 and Frederic Fabry 3 Received February 4, 1998; revised May 19, 1998 A new 3-phase ac plasma reactor has been developed within the framework of research on hydrocarbon cracking for the production of carbon black and hydrogen. (1,2) One of the main characteristics of the system is related to the 3- phase, 50 Hz ac current plasma generator which induces a very particular arc motion affecting the heat and mass transfer inside the reactor. In a first step, the general flow inside the reactor in the absence of hydrocarbon injection has been studied. A simplified approach to characterize the heat and mass transfer inside the reactor is presented in this paper. The arc zone analysis is carried out simul- taneously by a theoretical analysis of the electromagnetic forces and by an ultrahigh-speed cine-camera analysis. The flow in the reactor is modeled with a CFD commercial code. Results are compared with experimental temperature measurements. KEY WORDS: Three-phase; ac thermal plasma; flow modeling; Lorentz forces; heat and mass transfer. 1. INTRODUCTION Three-phase electric arcs are used in many large-scale industrial pro- cesses, particularly in steelmaking and silicon metal production. Based on a similar technology, 3  and in order to show the feasibility of a new plasma process on a pilot scale, a 100-kW 3-phase ac plasma furnace for carbon black production from hydrocarbon cracking has been set up within the framework of a collaboration between Ecole des Mines de Paris, CNRS, EDF, GDF, and TIMCAL G + T. 1 Centre d'Energetique, Ecole des Mines de Paris, Rue Claude Daunesse, B.P. 207, F-06904 Sophia Antipolis Cedex, France. 2 NTNU, Department of Metallurgy, N-7034 Trondheim, Norway. 3 IMP, CNRS, B.P. 5, Avenue Felix Trombe, F-66125 Font Romeu Cedex, France. 69 0272-4324/99/0300-0069$ 16.00/0 © 1999 Plenum Publishing Corporation