Patent GB-155835-A (GB)
Title: Improvements in filter electrodes for electrolysis
IPC: C25B11/03
Filed: 1920-12-24
Abstract: 155,835. Traun's Forschungslaboratorium Ges., H. O. July 6, 1918, [Convention date]. Electrodes; connections; preparing surfaces; electrolytes, circulating; non-metallic substances, obtaining'. -An electrode is built up of elements superimposed in planes parallel with the direction of flow of a fluid which is forced through it. The porositv may be adjustable. In one form of electrode the porous mixture surrounds a perforated pipe 1, Fig. 5. The material may be directly in contact with the pipe, or connection may be made by two or three bars 11, 12 having projections passing through slots in the pipe to engage cones 10 on a rod 9 bearing a nut 8 by means of which the bars 11, 12 can be forced into contact with the porous substance. The porous material may be carbon, graphite, metal powder, or metal wool or shavings, reinforced by annular metal plates or pieces of gauze, preferably corrugated. Annular pieces of gauze may themselves form the porous material, reinforcing rings of sheet metal being added for high liquid pressures. Graphite, or metal powder or wool, mixed with molasses, may be spread between sheet or gauze rings and then dried or carbonized. Short cylindrical coils of wire wound on perforated or gauze cylinders are also suitable. Wire used in making the coils or gauze may first be wrapped with fine wire or yarn. Metal discs roughened by etching or otherwise, or perforated, may be superimposed. Discs of metal gauze alternating with asbestos or cloth discs are also suitable. A catalytic material favouring the reactions desired at the electrode may be applied as a paste to the gauze or perforated or corrugated plates. The large holes present in the gauze or coil electrodes may be reduced by forcing through the electrode a suspension of graphite, lamp-black, soot, metal powder, or colloidal metal, or salts of heavy metals which are afterwards reduced to conducting oxides or metals. Mercury is useful for the same purpose. Porous metal may be electrodeposited on the inside or outside of the electrode. The porous mass is adjustably compressed, to vary its porosity, by a nut, a cup 4, and a flange 2; the cup and flange may be shaped so as to compress the outside more than the inside material. Insulating-material covers the non-porous external parts of the electrode. Gases, liquids, or solids in the form of suspensions or emulsions may be forced through the porous electrode, for reduction, hydration, dehalogenation, condensation, polymerization, oxidation, or halogenation. Amalgamated electrodes are suitable for the conversion of acetylene into aldehyde or acetic acid. Electrolysis may be combined with dialysis or osmose. The Specification as open to inspection under Sect. 91 (3) (a) describes also another arrangement, comprising elongated pieces of gauze &c., perforated for the passage of bolts 23, Fig. 11 (Cancelled), by which they are compressed together. These bolts pass through or into boxes within cupped end plates, one of which is provided with a supply pipe. Passages 29 for the liquid are provided in the porous material. Conductors 42 may be attached to the gauze &c. by soldering or welding. Such an electrode may be mounted in a closed cell provided with a steamjacket. Products can be distilled off through an outlet in the cover. It is also stated that parts of electrodes may be coated with gold or platinum for use in acid solutions, but otherwise may be of iron-nickel, iron-aluminium, iron, or steel. This subject-matter does not appear in the Specification as accepted.