The aim of this work is to ascertain the parameters that have the greatest influence on the yield of ozone produced via corona discharge. This research will be carried out in conjunction with the Research and Development section at Ionics Watertec Pty Ltd, as a joint effort in their long-term goal of redesigning their ozone generator.
This report is the first of a series of two, where the first study has been carried out in the first semester of 2001 and the second study will be carried out in the second semester of 2001. The first report outlines and critically examines the findings of past research on the various sections of ozone production. It encompasses the studies carried out from air preparation to ozone production to contact chambers. Through the literature review, the parameters that significantly influence the production of ozone will be sought. Included in this report is a set of preliminary experiments of what is believed to be the most important parameters. Conclusions and recommendations based on the findings are also presented.
The report discusses the optimisation of ozone production through corona discharge. It covers the many aspects related to the production of ozone beginning from air preparation right through to the dissolution of ozone into the solvent, or aqueous media which is to be treated.
The applications of ozone are also covered. These are extensive and range from the treatment of industrial effluent or applications to marine life and water fit for consumption. The vast areas that use ozone as disinfectant show that the use of ozone throughout will be more common as ozone becomes a more economically feasible option. A literature survey has been presented which outlines the various methods and technologies that are present throughout the world. It also shows the focus of the various studies that has been carried out in the recent years.
It can be conclusively said that some of the most researched parameters are the effect of gap spacing, and temperature, where models predict maximum efficiency at narrow gaps. Thus, operation under narrow discharge gap widths and accordingly optimised high gas pressure has a strong advantage in producing high concentration ozone efficiently because of the suppression of nitrogen oxide generation and gas temperature rise. In terms of experiments, there were some experiments that were carried out to ascertain and confirm the dependency of the ozone production on the discharge gap length. As predicted by the literature, the smaller the gap the greater the yield in ozone. However the experiments also were found to contradict the literature in terms of pressure, as it was found that increasing the pressure of the feed decreased the production of ozone. Also, pressurisation of the feed gas will result in lower temperatures of the exit gas. Thus effect of lower temperatures in terms of the diffusion efficiency of the ozone into the water must be considered.