Ozone generation in air and N₂ + O₂ mixtures in wire-to-cylinder reactors – an optimization attempt

Abstract

The experimental results obtained with a wire-to-cylinder ozone generator (5–20 cm in length, inner diameter ≈ 12mm), using a 5 to 60 l/h flow-rate range of air or N₂ + O₂ mixtures, a negative DC high voltage being applied to the wire, are analyzed.

As for the “classical” industrial ozonizers, the chemical engineering method, based on the energy density concept (Becker parameter β = P/Q) and the global coefficients of formation K _f and destruction K _d of ozone, was applied. Some peculiar behaviours of the K _f coefficient and the role played by nitrogen and its excited levels are pointed out. The results obtained are compared with those of other authors. It appears clearly that the main parameters are not only the Becker parameter but also, and independently, the applied electrical power (P) and gas flow rate (Q) through the residence time (t _r), acting on the temperature of the reactant gas inside the reactor. It seems that t _r needs to be higher than about some seconds.

As with oxygen, an optimization of the ozone production in a wire-to-cylinder ozonizer can be founded on the economical criterion γ = β/C ² or its inverse C.η more directly measurable in the usual practice.