Abstract: An apparatus for electrochemical indication of the final stage of a titration analysis has a first indication electrode located in an electrochemical titration container connected by a switch to a sampling current amplifier feeding a recorder. Both the amplifier and the switch are controlled by a timing circuit which causes the switch to connect and disconnect the electrode to the amplifier. By only connecting the electrode to the amplifier for a brief time and activating the amplifier for a brief time thereafter, the instantaneous value of indication current is obtained. During the remaining time period, the indication electrode is galvanically disconnected from the amplifier and consequently, no reduction of concentration of electroactive substance in the proximity of the electrode occurs and an extremely high current response is attained.

Abstract: Method of biological activating cleaning of waste waters containing nitrogenous materials at conditions of a lowly loaded sludge with simultaneous nitrification of organic nitrogen and ammonia to nitrates while using fluid filtration and an arrangement for execution of this method where the waste water, after its activating cleaning with supply of oxygen, is subsequently cleaned in the course of fluid filtration by denitrification without presence of oxygen creating flotating sludge which is circulated at least partly to the aerobic activating cleaning.

Abstract: Block short-way evaporator with wiped-off film for vacuum and molecular distillation which is suitable for large-scale production. The evaporator is composed of one or more vacuum chambers in which parallel vertical double-sided flat evaporators with wipers for wiping evaporating areas and double-sided flat condensers are alternately located so that they form a continuous block. On the bottom of each chamber distillate collecting troughs with distillate tubes are formed alternately below double-sided flat condensers using separating partitions, and below double-sided flat evaporators residue collecting troughs with residue outlet tubes are formed, feed tubes being led through the bottom and the double-sided flat evaporators into separating troughs in the upper part of the double-sided flat evaporators.

Abstract: A liquid seal for a multistage molecular evaporator which is in the form of an elongated vessel having convex evaporating surfaces for carrying out a continuous redistillation. The evaporator includes at least two vacuum stages superposed one over the other in the vessel. The upper stage has two inwardly extending troughs one superposed over the other. An overflow tube extends from the upper trough into a collecting trough of the adjacent lower vacuum stage to form a first liquid seal. A collecting member in the upper stage extends into the lower trough of the upper stage to collect distillate therein and to form a second liquid seal therein. The upper and lower vacuum stages have evaporator bodies which are connected to each other by sealing means.

Abstract: A method for the continuous decomposition of stable carbon dispersions in waste engine oils, the decomposition being immediately followed by an oil re-refining step as, preferably, a short-path distillation. In accordance with the invention, waste oil is heated, under a pressure ranging from 1 to 100 Pa, in the form of a thin film (0.1 to 2 mm thickness) to a temperature of 200.degree.-300.degree. C., whereby liberated vapors together with entrained microdrops condense at a temperature of 20.degree.-100.degree. C. Thereupon the condensate is immediately subjected to a short-path distillation to be re-refined. The entire process is advantageously effected in a single apparatus.

Abstract: Method and apparatus for dispensing multi-component liquids in suspension in which at least two nozzles are placed to direct two different liquid suspensions into each other at different flow rates to cause oscillation and turbulence at the boundary between the two streams.

Abstract: A technique for forming single or multi-layer sheets of fibrous material having a controllable fiber distribution is described. A pair of spraying rollers each having a system of circumferentially spaced radial vanes on its surface are supported within the upper portion of a working zone defined between a pair of continually advancing, downwardly converging sieves that are disposed symmetrical to a longitudinal axis. The rollers are rotated in respectively opposite directions to intercept at least one fibrous suspension downwardly directed into the working zone, and to thereafter propel the intercepted liquid outwardly and downwardly toward the sides of the working zone in symmetrical fashion. The fibrous layers thus built up on the advancing sieves converge into the final sheet in the lower portion of the working zone. Separate facilities are associated with the upper and lower portions of the working zone for drawing liquid from the formed layers outwardly through the sieves.

Abstract: Method of carrying out filtration using semi-permeable membranes in apparatus of the type having a plurality of frustoconical sections defining an annular type space between the various sections, each section having a membrane thereon, the steps comprising passing a solution to be treated along the spaces between the various sections in converging and/or diverging flow paths.