Ozonisers

Claim 2

An ozoniser having at least one pair of electrodes with an oxygen-containing gas and dielectric material in the gap between the electrodes wherein means are provided for applying between said electrodes a direct potential, switched to be alternately of opposite polarity, said means comprising a step-up transformer having primary and secondary windings with at least one primary winding arranged for energisation from an alternating power supply source, rectifying means connected to said secondary windings to produce a high voltage direct power supply, power supply lines connected to said rectifying means to be maintained at positive and negative direct voltages with respect to a datum potential, means connecting one electrode of said pair to a point at said datum potential, means connecting the other electrode of said pair both to the cathode of a first grid-controlled gas discharge device and the anode of the first gas discharge device and the cathode of the second gas discharge device being connected respectively to said positive and negative supply lines, and a controllable frequency pulse generator arranged to apply trigger pulses alternately at a controllable frequency to control grids of the two gas discharge devices whereby they fire alternately.

Claim 3

An ozoniser as claimed in claim 1 wherein said grid-controlled gas discharge devices are thyratrons.

Claim 4

In an ozoniser comprising a metal electrode facing a dielectric backed by a conductive liquid electrode, means for passing oxygen-containing gas between the metal electrode and dielectric, a first cooling system for cooling said metal electrode with a liquid coolant for removing heat from the electrode, a second cooling system for cooling said dielectric by flow of or by circulating the liquid of said liquid electrode over the surface of the dielectric; the improvement comprising means for applying between said electrodes an alternating voltage comprising positive and negative polarity high voltage supply lines, power supply means including a step-up transformer and rectifiers connected to said transformer to rectify the stepped-up voltage therefrom, said rectifiers furthermore being connected to said high voltage supply lines for maintaining positive and negative voltates with respect to a datum potential, means connecting one electrode of saiD electrodes to a point at said datum potential, first and second switches each having first and second terminals between which connection is made by application of an electrical operating pulse to the switch, means connecting the other electrode of said electrodes both to the second terminal of the first switch and the first terminal of the second switch, the first terminal of the first switch and the second terminal of the second switch being connected respectively to said positive and negative supply lines, and a controllable frequency pulse generator arranged to apply operating pulses alternately at a controllable frequency to the two switches whereby they conduct alternately.

Claim 5

In an ozoniser comprising a metal electrode facing a dielectric backed by a conductive liquid electrode, means for passing oxygen-containing gas between the metal electrode and dielectric, a first cooling system for cooling said metal electrode with a liquid coolant for removing heat from the electrode, a second cooling system for cooling said dielectric by flow of or by circulating the liquid of said liquid electrode over the surface of the dielectric; the improvement comprising means for applying between said electrodes an alternating voltage comprising positive and negative polarity high voltage supply lines, power supply means including a step-up transformer and rectifiers connected to said transformer to rectify the stepped-up voltage therefrom, said rectifiers furthermore being connected to said high voltage supply lines for maintaining positive and negative voltates with respect to a datum potential, means connecting one electrode of saiD electrodes to a point at said datum potential, first and second switches each having first and second terminals between which connection is made by application of an electrical operating pulse to the switch, means connecting the other electrode of said electrodes both to the second terminal of the first switch and the first terminal of the second switch, the first terminal of the first switch and the second terminal of the second switch being connected respectively to said positive and negative supply lines, and a controllable frequency pulse generator arranged to apply operating pulses alternately at a controllable frequency to the two switches whereby they conduct alternately.

Claim 6

An ozoniser as claimed in claim 3 wherein said switches are grid-controlled gas discharge devices.

Claim 7

An ozoniser as claimed in claim 3 wherein two storage capacitors are connected respectively between the two supply lines and said datum potential point.

Claim 8

An ozoniser as claimed in claim 3 wherein said controllable frequency pulse generator is arranged to produce a pair of control pulses for the two switches at a controllable frequency between 50 Hz and 20 KHz.