Abstract: Screw extruder for working plastic compositions, especially polymers and rubber mixtures having a cylinder in which a motor-driven screw is disposed. The cylinder being provided with pins which are disposed in planes perpendicular to the cylinder axis and can be pushed radially through openings in the cylinder wall, and the screw being provided in the pin planes with gaps in the screw spirals. The object of the invention is to create a practically achievable and economical possibility for the shifting and depth adjustment of pins in screw extruders. A plurality of pins, lying in an axis parallel row, are fastened to a beam at the extremities projecting from the extruder cylinder.

Abstract: A process for the production of panels, webs, panel-like moldings or profiles from plastics, of high mechanical strength owing to a molecular orientation by compressive roll-stretching within the nip of at least one pair of pressure or compression rolls at roll and material temperatures below the crystallite melting point or the softening point of the plastic and above 303.degree. K. under compressive stretching. The compressive roll-stretching of the panels, webs, panel-like moldings or profiles takes place with the same or approximately the same circumferential speed of the pressure or compression rolls or without friction at pressures of 20 to 250 MPa, at a degree of compressive stretching of over 1.1.

Abstract: A supporting matrix for catalytically active compounds, for use, for example, in catalysts for the catalytic cracking of nitrogen oxides, is constructed of a metal core (1), an intermediate layer (3) of vitreous enamel bonded onto this core, and a porous ceramic cover coating (5) applied to the vitreous enamel intermediate layer.The supporting matrix is made by dipping the metal core into a vitreous enamel slip followed by firing at 800.degree. to 900.degree. C. The enameled metal core is then fired in a second firing to form the ceramic cover coating which represents the actual support for the catalytically active compounds.

Abstract: Method for the selective elimination of nitrogen oxides from flue gases, especially from the flue gases from furnaces.For the denitration, the flue gases are brought together with catalytically active solid bodies through which the flue gases can flow on account of their structural makeup and/or because they are in the form of a loose bed. A reducing agent, mixed if desired with a carrier gas, is brought in contact with the catalytically active solid or sections thereof, in alternation with the flue gases containing the nitrogen oxides that are to be reduced.

Abstract: A process and device for cleaning a rotary regenerative heat exchanger with a rotating part and a storage mass, for the transfer of heat from a higher-temperature, contaminated gas stream to a lower-temperature clean gas stream, in which upon reduction of the rotatory speed of the rotating part, jets of a cleaning agent and, immediately thereafter, jets of a gaseous drying agent, are sprayed onto the storage mass, with a continuous or step-wise radial displacement of the jets from the circumference to the center of the rotating mass and vice versa. The device includes a carriage, which is guided and driven radially over the storage mass. At least one nozzle each for a cleaning agent and a drying agent are on the carriage. A drive is associated with the rotor for establishing variable running speeds and lower cleaning speeds and for varying the rotatory speed of the rotor depending on the position of the carriage between the center and the circumference.

Abstract: Selective elimination of nitrogen oxides contained in the exhaust gases from furnaces.With the addition of ammonia to the exhaust gases and acceleration of the reaction by a catalyst, the nitrogen oxides are reduced to molecular nitrogen and water. The procedure is such that the catalyst is traversed in one zone by the exhaust gases and in a zone separate therefrom by the fresh air being fed to the furnace as combustion air, while the position of the zones traversed by the exhaust gases and by the fresh air is changed continuously or step-wise such that the zone first traversed by the exhaust gases is then traversed by fresh air, and vice versa.The ammonia is mixed with the fresh air before it enters the catalyst, bound to the surface of the catalytically active material, and carried along into the zone traversed by the exhaust gases, where the reduction of the nitrogen oxide then takes place.

Abstract: Heat exchanging or accumulator structure for thermal transfer between gas streams in regenerative heat exchangers, especially for the transfer of heat between the boiler exhaust gases cleaned in a scrubber and the foul boiler exhaust gases being fed to the scrubber, composed of molded elements (2; 4a; 4b; 4c) of thermoplastic material selected from the group consisting of polyphenylene oxide, a copolymer of polyphenylene oxide, polystyrene, and polyblends of polyphenylene oxide and polystyrene.

Abstract: The storage material is intended for the transfer of heat between gas streams in heat exchangers, and has stick-like molded spacing elements (12) on the one hand, and a plurality of plate-like molded elements (12) of heat-resistant plastic serving as storage elements on the other, which are assembled into storage blocks. Polyetherimide is used as the material for the molded elements (10; 12), which combines sufficiently high heat resistance with resistance to aggressive chemical influences.

Abstract: Hot gas filter for separating solid particles carried along in high temperature or waste gases having a filter casing made of heat-resistant brickwork, in which there is provided at least one oblong filter cell one end of which ends in a hot gas supply duct whereas the other end is tightly closed by a removable cover. The walls of the filter cell are at least partly made of perforated bricks, through which the hot gas entering the filter cell may overflow to a treated gas discharge duct. The filter cell is lined over the whole length thereof with a replaceable filter hose of heat resistant fabric or tissue, preferably non-woven ceramic fiber fabric or a fabric of ytrium-oxide stabilized zircon-oxide fibers.