Generally, ozone is generated by using silent discharge or surface discharge, however, the energy efficiency of ozone generation by using only one kind of discharge is about 200g/kWh. The energy efficiency of ozone generation is about 1/5 of the theoretical energy efficiency. There is ozone decomposition at the condition of high concentration, heat decomposition and so on. In order to increase ozone generation efficiency, many studies of the ozone generation method have been carried out up to now.
Experiments of ozone generation by using surface discharge and UV rays were carried out. In the experiment of superposing surface discharge and UV rays in the same space, the ozone yield by the superposing mode is lower than each of the ozone yield by surface discharge and by UV rays at the same power. It is supposed that noticeable ozone dissociation by UV rays occurs because high ozone concentration is achieved by the superposing mode. In the case of cascade connection of a surface discharge reactor and UV lamp reactor, the ozone yield of the cascade mode (from UV lamp reactor to surface discharge reactor) is higher than that of the superposing mode at the same power. It is confirmed that cumulative dissociation is an effective reaction on ozone generation.