Development of High Efficiency Ozone Generation Using Non-equilibirum Plasma Based on Hydrodynamic Instability

传统上，臭氧是用非平衡等离子体无声放电从氧气中产生的。为了有效地分离非平衡等离子体（无声放电）中产生的臭氧和环境氧，提出了一种新的臭氧发生器。分离原理是基于臭氧和氧气的离心力之间的差异，以及与泰勒不稳定性相关的流体运动。为此，设计了一个由固定外圆柱形电极和旋转内圆柱形电极组成的环形原型。外电极为带冷却管的铜块（电极内径42mm）；内电极为耐热玻璃圆筒，圆筒内壁镀镍（电极外径40mm）。在固定电压为10kV的条件下，改变氧流量、内电极转速（0 ~ 4000rpm）和供电电流频率（250 ~ 2000hz）进行实验。在低流量条件下，内电极旋转的影响是显著的。这是因为在流量较小的情况下，供氧在排出段内的停留时间相对较长。臭氧浓度随旋转速率的增加而增加，达到的最大臭氧浓度约为不旋转时的1.5倍。然而，随着内电极旋转速率的增加，臭氧生成效率并没有明显提高。因此，在现阶段，我们的目标还没有完全实现；为了找到建议的原理正常工作时的最佳条件，有必要对这些现象进行详细的澄清，作为本研究的下一步。

Conventionally, ozone was produced from oxygen using non-equilibrium plasma silent discharge. A new ozone generator has been suggested in order to effectively separate generated ozone from ambient oxygen in non-equilibrium plasma (silent discharge). The separation principle is based on the difference between the centrigugal forces for ozone and oxygen, and the fluid motion associated with Taylor instability. To this end, an annular shaped prototype composed of a fixed outer cylindrical electrode and a rotating inner one was designed. The outer electrode is a copper block with cooling pipes (the inner diameter of the electrode is 42mm) ; the inner electrode is the Pyrex cylinder, the inner side of which is plated with nickel (the outside diameter the electrode is 40mm). Experiments were conducted varying the oxygen flow rate, and the rotation speed of the inner electrode (0-4000rpm), and the supplied electrical current frequency (250-2000Hz) with the fixed voltage of 10kV.The effect of the inner electrode rotation is significant for low flow rate. This is because the residence time of the supplied oxygen inside the discharge section is relatively longer for smaller flow rate. The ozone concentration increases with increasing rotation rate, and the attained maximum ozone concentration is about 1.5 times as large as that without rotation. However, the ozone generation efficiency is not so improved with increasing rotation rate of the inner electrode. Hence, at the present stage, our aim has not been fully realized ; in order to find the optimum condition when the suggested principle works properly, the detailed clarification of the phenomena is necessary as a next step of the present study.