The present invention relates to apparatus (known as ozone generators) for enriching air or another oxygen-containing gas with ozone. More particularly, the invention relates to improvements in ozone generators of the concentric-tube or twin-tube type wherein the inner and outer walls of the tube define an annular chamber through which the oxygen-containing gas flows between a first electrode which is applied to the outer side of the outer wall and a second electrode which is applied to the inner side of the inner wall of the tube.
Presently known ozone generators of the twin-tube type failed to gain widespread acceptance because they are too complex and too expensive. Furthermore, known ozone generators of the just outlined character are not sufficiently safe for use by unskilled or careless persons and/or in areas which are contaminated with dust or other foreign matter. For example, depositions of dust on the walls of a twin-tube type ozone generator can entail the flow of creep currents along the shortest path between the inner and outer electrodes; this can result in a short circuit, severe damage to the source of high voltage which is applied across the electrodes when the ozone generator is in use, and danger or injury to the person or persons nearby.