Patent DE-102008020659-A1 (DE)
Title: Producing chemically active substances e.g. chlorine in liquid media e.g. water, comprises immersing electrodes in a liquid to be processed in which a pulsed corona discharge is produced by applying pulse-shaped high voltage at electrodes
Inventor: HARTMANN WERNER
IPC: C02F1/467
Filed: 2008-04-24
Abstract: The method for producing chemically active substances in liquid media, comprises immersing electrodes in a liquid to be processed in which a pulsed corona discharge is produced by applying a pulse-shaped high voltage at the electrodes, triple-points are formed by inserting a third material in addition to the electrode material and the liquid, the input voltage of the corona discharge is reduced with the materials selected for the third material and initial points of the corona discharge are produced by characterizing the electrodes using pulse-shaped high voltage over the electrode surface. The method for producing chemically active substances in liquid media, comprises immersing electrodes in a liquid to be processed in which a pulsed corona discharge is produced by applying a pulse-shaped high voltage at the electrodes, triple-points are formed by inserting a third material in addition to the electrode material and the liquid, the input voltage of the corona discharge is considerably reduced with the materials selected for the third material, initial points of the corona discharge are produced by characterizing the electrodes using pulse-shaped high voltage over the electrode surface distributed at several locations, energy-rich electrons develop in the corona discharge and further new triple-points are created by exposing corresponding areas during a surface erosion by ablating metallic components or breaking out the non-conductive components. The energy-rich electrons convert liquid molecules into radicals, which decompose and create the pollutant molecules on their parts. A material selected for one of the electrodes is made of conducting/non-conducting composite material, with which the triple-points expose at the electrode surface, where the triple-points are formed at the transition between the conducting and non-conducting and/or surrounding medium. A metal-ceramic-composite such as cermet is used as conducting/non-conducting composite material. A counter electrode made of a conductible material such as stainless steel inert against the liquid is used. A lattice made of a wire is used with a smaller diameter than the electrode. The local electrical field strength is strongly increased in the environment of the electrode. The wire lattice that is made of the conductible material such as stainless steel inert against the liquid is coated with a ceramic on half side with small distance or mechanical contact of the electrodes. The metal-ceramic liquid results electrical field strength (E) at the triple-points i.e. E=electrode voltage/electrode distance, which is increased around a factor (F) with F=epsilon liquid/epsilon ceramic, which leads to release the electrical discharges at the triple-points. The factor (F) of 10 is selected for increasing the electrical field strength at the triple-points. Independent claims are included for: (1) a device for producing chemically active substances in liquid media; and (2) a method for producing a device.