Abstract: The present invention is directed to an electrolytically produced screening material for the removal of fibers from suspensions during the production of pulp and paper. The screening material is a thin, smooth metal foil having perforations on the order of 10-80 .mu.m. And an open area of 5% to 40%.

Abstract: The patent claims concern a method for a more efficient "wet ?combustion! oxidation" of COD-containing effluents from industrial processes and municipal plants and for a more efficient COD-reduction by enzymes in aerobic and anaerobic biological cleaning processes and for same sorts of effluents. The method implies a strong increase of the reaction speed between added oxygen and the elements in the liquid to be oxidized through so-called "Turbo Oxidation", which implies that the liquid is submitted to strong movements nd turbulence during several circulations within one or more liquid circuits during continuous addition of oxygen. By the same method, COD reduction by enzymes can also be made more effective. The single circuit is placed in connection to and communicates liquid-wise with a pressurized reaction tank, from where the developed reaction gases are continuously let out.

Abstract: The apparatus consists of one or more electrolytic cells containing electrodes made out of metal foils perforated with a very large number of microscopic holes, through which electrolyte is sprayed or pumped, creating a large contact area between the electrolyte and the conductive electrode material. The apparatus can be used for the production of bleaching and oxidizing liquids, both "in-line" and "off-line," for de-lignification and/or bleaching of cellulose fibers or other solids in suspension, or for oxidizing of organic compounds in liquids in connection with COD reduction or disinfection. The apparatus can also be used to create electrostatic effects on fines, colloids and chemicals in liquids, and thereby influence surface tensions, transfer of charges, electrokinetics and adsorption.

Abstract: Process for producing pulp suitable as raw material for paper, board or fiberboards and similar products. A pumpable alkaline slurry of fibrous raw material is conducted through a pressurized tube system by the use of pulp pumps, the pressure increasing in steps from the beginning of the process to the end of the process. On its way the slurry is repeatedly dewatered and rediluted with process liquid. An apparatus suitable for being used in carrying out the process comprises a dewatering tube (64) and a dewatering and venting tube (67) arranged centrally and axially within the tube (64) which may be provided with a perforated part (66). The tube (67) is provided with perforations (68) through which gas and liquid from fiber-containing slurry introduced into the outer tube (64) can escape. At the opposite end from the inlet end of the outer tube (64) there is an outlet (72, 65) for thickened fiber-containing slurry.