A method of controlling the power used and the ozone generated by an ozone generator. The rate of gas flow through the generator (and/or also the temperature or pressure) is used to either adjust or to limit the output of the power supply. A control signal derived from the gas flow rate is fed to the power supply, influencing its output and thereby affecting the power drawn by the ozone generator. This method enables the concentration or the total quantity of the ozone generated to remain relatively constant with varying gas flow rate, or it can continuously regulate the power level so as to automatically generate the highest possible ozone concentration at any flow rate. In addition, this method allows a single power supply and ozone generator to feed ozone to multiple users with different and/or varying demands, while holding the ozone concentration constant as the users go on and off independently of each other.

An ozonizer formed of an interior electrode in the form of an electrically conducting tube arranged concentrically in an electrically insulating tube and spaced at a distance radially therefrom to form a discharge channel. The electrically insulating tube has an exterior surface on which are provided at least two parallel electrically conducting sleeves, which are separated axially relative to one another and surrounding the insulating tube to form the exterior electrode of the ozonizer. Each sleeve is connected respectively by way of a switching element to an energy supply device. The electrically conducting tube is also connected to the energy supply device.

Gaseous ozone is admixed and stored with water under such conditions that the density of ozone in the water is increased above the normally obtained and held stabily at such levels so that it may be efficiently transported through the processing plant being cleaned. Specifically, the present invention provides for the chilling of the ozone and water carrier to increase density and permit the subsequent increase in temperature to cause propulsion of the water and ozone through the plant to be cleaned in-place.

A method and apparatus for generating an adjustable concentration of a selected gas within a carrier gas flow including a gas generator which is responsive to a drive signal. A gas analyzer detects the selected gas concentration within the carrier gas flow from the gas generator and provides a signal proportional to the measured concentration to a comparator. A gas concentration selector provides a second signal to the comparator, the signal being proportional to a desired concentration of the selected gas. In response to these signals, the comparator adjusts the drive signal to correct the gas generator output for the difference between the signals and to thereby substantially adjust the concentration of the selected gas within the carrier gas flow to the desired concentration. The method and apparatus automatically corrects for drift or other inaccuracies associated with the generation of the selected gas.

An ozone generating apparatus has a plurality of ozone generating units connected in series to form a plurality of stages along the flow path of a gas. Each ozone generating unit has an ozonizing chamber having a material gas inlet and a product gas outlet and ozonizer discharge electrodes disposed in the ozonizing chamber and connected to an AC high-voltage source. The voltage applied to said ozonizing discharge electrodes of each successive stages is so varied that the ozonizing discharge electrodes of each downstream stage, as viewed in the direction of flow of the gas, is supplied with a lower voltage than the voltage supplied to said ozonizer discharge electrodes of an adjacent upstream stage. A series connection of a plurality of ozone generating units can form a composite ozone generating unit, and a plurality of such composite units may be connected in series to form a plurality of stages. The voltages applied to such successive stages is varied in the same manner a above. The ozone generating unit and the AC high-voltage source can have modular construction.