Kernforschungsanlage Julich Gesellschaft MIT Beschrankter Haftung

Kernforschungsanlage Julich

Forschungszentrum Julich Gmbh

Elo-chem Atztechnik Gmbh

Brooks Instrument, Zweigniederlassung Elmshorn Der Emerson Electric Gmbh

Leander Furst

Bertel Kastening

Walter Holzer

Wolfgang Faul

Jiri Divisek

Reinhold Flucht

Herbert Neumeister

Harald Luft

Johan T Ballast

Herbert Neumesiter

Kurt Jahnel

Device for removing hydrogen from a gas mixture and its use

In an electrochemical cell arrangement for the deionization of aqueous solutions by ion exchange including cathode and anode chambers having electrodes disposed therein, a brine chamber is disposed between, and directly adjacent to, the cathode and anode chambers which are filled with anion and cation exchanger materials such that the electrodes are directly in contact therewith and means are provided for conducting the aqueous solution to be treated through the cathode and anode chambers and means for passing brine through the brine chamber to be charged therein by the ions removed from the aqueous solution in the cathode and anode chambers.

Electrolytic cell arrangement for the deionization of aqueous solutions

In a process for reduction or oxidation of materials in aqueous solution by assing a reagent gas through a finely porous catalyst layer into the solution, bodies of electrically conducting material which in the aggregate have a large surface are brought into electrically conducting connection with the catalyst layer on its side facing the solution in order to increase the rate of conversion of the dissolved material. The conducting bodies are distributed in the solution at least in the region of the catalyst layer and increase the effective surface for the conversion of the dissolved material. The invention is particularly useful in connection with catalyst layers provided with an electrically conducting protective cover through which gas and solution may pass on the side of the catalyst layer facing the solution as disclosed in a related application of the same inventors Ser. No. 500,941 filed June 3, 1983.

Process for reduction or oxidation of materials in water solution by

A gas flow regulator for gases with condensable components, which delivers ases at constant pressure with constant average composition comprising a gas flow control mechanism, preferably including a spring-loaded membrane bounding a receiving chamber, which is subjected to the pressure of the gases flowing in and which an inlet valve control; and a cooling section connected and vertically oriented to the gas flow control mechanism by which the proportions of the condensable components are held at a partial pressure given by the cooling temperature, and a means for maintaining the gas flow control mechanism at a temperature above the condensation point. A restrictor, preferably an adjustable outlet valve, is connected after the cooling section to help maintain the membrane under pressure by the flowing gas, from which all condensate formed arrives in the region below the regulator directly by action of the force of gravity.

Gas flow regulator for gases with condensable components

Ammoniacal etching solution containing metal ions as the result of etching is withdrawn from an etching bath and while part of it goes to an electrolysis cell for removal of metal ion, the remainder goes back to the etching bath through a liquid jet pump in which it serves as the working liquid, while the pump sucks in from the electrolysis cell the anodically evolved oxygen. The thorough mixing of the oxygen into the etching solution performed by the pump results in oxidation so rapid that in many cases it becomes unnecessary to suspend catalyst particles in the electrolyte to accelerate the oxidative regeneration of the etching solution. Where use of such particles is still desired, the solution drawn from the etching bath goes through a cylindrical filter unit from which a filtrate is drawn off laterally for the electrolysis cell, while the remainder of the input goes to the jet pump. Controls are provided for using the electrolysis cell only when the metal ion concentration is above a predetermined value, for adding ammonia to the oxygen line in order to maintain a particular value of pH and for controlling the temperature of the electrolyte in the electrolysis cell in order that a desired quantity of water can be condensed from the oxygen line for use in rinsing the work pieces after they are taken out of the etching bath.

Method and apparatus for regenerating an ammoniacal etching solution

The addition of a small quantity of ammonium chloride to an ammonium sulf etching solution results in shortening the regeneration time of the spent etching solution when air or oxygen is bubbled through it to reoxidize it, and it also results in accelerating the etching rate. The extent of this improvement deteriorates with increasing chlorine ion content, disappearing when the chlorine ion content substantially exceeds 0.4% by weight of the solution and still greater chlorine ion additions are distinctly undesirable. The electrolysis of the etching solution to remove etched-away metal cathodically produces enough oxygen at the anode to prevent any substantial evolution of chlorine from the electrolytic action on the small chlorine ion content.

Ammoniated etching solution and process for its regeneration utilizing

The intermittent electrolysis of a portion of the used ammoniacal etching solution generates oxygen at the anode which is mixed into the remainder of the circulated etching solution for reoxidation and regeneration before it is returned to the etching chamber. The portion of the solution which goes through the electrolysis cell, and has its metal content reduced, is returned to the beginning of the circulation loop rather than to the etching chamber, in order that the metal content of the circulated solution may be quickly reduced. This reduction is quickly picked up by a metal content measuring device in the branch supplying solution to the electrolysis cell. When the metal content is below a certain level, the solution in that branch is returned directly to the beginning of the circulation loop, but when the metal content exceeds the threshold, it is valved into and through the electrolysis cell until the metal content as measured in the line leading to the electrolysis cell drops below its lower threshold value.

Regeneration of an ammoniacal etching solution with recycling of

The invention is concerned with an electrochemical gas analyzer for determining the sulphur dioxide content of certain gases in particular, flue gases. The device comprises a measuring cell containing a measuring electrode for the determination of the depolarization current and further comprising an unpolarizable electrode in the same electrolyte. The gas input flow is utilized to cause a circulation of electrolyte containing the dissolved gas which moves in the space between the measuring and counter-electrode. The electrolyte is continuously renewed and the electrolyte leaving the cell is regeneratd and recycled. The sulphur dioxide dissolved in the electrolyte is removed outside the cell by treatment with air in the presence of activated charcoal.

Electrochemical gas analyzer for determination of sulphur dioxide

In addition to catalyzing the reoxidization of spent alkaline etching age the suspension of activated carbon powder in the etching solution also increases the speed of etching when the etching solution is recirculated in the etching of printed circuit boards. The ammonium sulfate etching solution is set to a pH of about 9 by the addition of ammonia gas. In the recirculation of the etching solution, a part of the solution can be freed by filtration from suspended carbon particles and passed through the cathode and anode chambers of an electrolysis cell for the recovery of the etched metal by deposition on the cathode. The activated carbon powder for this purpose is calcined before use, at a temperature of between 900.degree. and 1200.degree. C. in vacuum or in an atmosphere that is inert, reducing, or only slightly oxidizing as in the case of an atmosphere containing carbon dioxide, water vapor or both, in a concentration that does not appreciably oxidize the carbon particles.

Method of regenerating an ammoniacal etching solution

Method of etching of surfaces of copper or copper alloys by way of an aci solution containing an oxidizing agent. After removal of the copper surface, the etching solution is passed for regeneration of the oxidizing agent through an electrolysis cell having an anode and a cathode, with copper being deposited on the cathode. The etching solution is maintained free of chloride ions and contains as the oxidizing agent ferric sulfate in a concentration of up to about 140 g of Fe/1 etching solution, whereby the copper content of the etching solution is adjusted to at least 10 g Cu per liter etching solution, while the current density in the electrolysis cell is maintained at at least 2A/dm.sup.2.

Method of processing the surface of workpieces including particularly

Method of electrochemically processing metallic surfaces of workpieces wh are arranged in an electrolyte of an electrolysis cell in such a way that the workpiece does not contact the anode and the cathode, with pulverous particles of one of the group consisting of graphite and activated carbon being suspended in the electrolyte, with the pulverous particles being charged on the anode for transfer of an electric charge to the workpiece. The pulverous particles are shielded by a diaphragm or an ion exchange membrane so that the charged pulverous particles cannot discharge at the cathode. In the electrolyte there is dissolved one of the group consisting of a V.sup.+5 compound and a vanadium-containing compound adapted to form V.sup.+5 ions at the anode of the electrolysis cell.

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Julich, Germany

Leander Furst