Abstract: The invention relates to a method and an apparatus for the polymerization of gaseous olefins, in particular of ethylene and at least one &agr;-olefin, in the gas phase in a stirred or fluidized, catalyst-containing polymerization zone (2) and at least one decompression zone (6, 10) downstream of the polymerization zone (2). The mixture of solid (co)polymer and unreacted monomers leaving the polymerization zone (2) flows through a settling zone, in particular in the form of a settling leg (14), before the decompression zone.

Abstract: In a method for granulating thermoplastic polymers, in particular thermoplastic polyolefins, the polymer powder prepared in the polymerization reactor is melted and homogenized in an extruder, then forced through an extrusion die and granulated. In accordance with the invention, the polymer powder is subjected to heat treatment before introduction into the extruder, resulting in the introduction of the polymer powder into the extruder being carried out at an elevated powder temperature. The invention is particularly suitable for the granulation of polyethylene or polypropylene.

Abstract: Ethylene/.alpha.-olefin copolymers are prepared by catalytic dry-phase copolymerization of the monomers in a stirred or fluidized polymerization zone, transfer of the resulting mixture of solid copolymer and unconverted gaseous monomer into a let-down zone and separation of the mixture, after pressure reduction, into a gaseous phase and a solid phase, by a continuous process in which the solid phase is continuously flushed beforehand with gaseous ethylene and then flushed with a mixture of nitrogen and steam. The ethylene copolymers are very substantially free of residual monomers and odor and flavor substances.

Abstract: Polyamide granules are dried and heated by feeding a suspension of granules in water into a sieve (1), where the bulk of the water is removed, and then into a tower dryer (10), where they are deposited in bed form and then freed of the remaining water while moving in plug flow under the force of gravity with a counter-current inert gas stream at from 70.degree. to 200.degree. C. The tower dryer possesses an inlet at the top (11) and outlet at the bottom (34) for the granules and also feed lines (20, 22, 31) for the inert gas. To achieve a uniform degree of drying of the granules, the inert gas is divided on entry into the tower dryer at a point between the drying zone and the heating zone into a stream which flows radially inward into the bed of granules on the one hand and a stream which flows radially inward and outward on the other. In this way the inert gas is distributed particularly uniformly and the granules are dryable in a very short drying zone down to a water content of 0.

Abstract: The instant invention relates to a process for the blending of bulk materials by means of a jet gas blender, whereby the blending porcess is initiated only when full gas pressure is reached and when the valve immediately upstream of the storage tank (3) has been closed. At the end of the set time period "t.sub.1 " the valve (4) leading to the blending container (6) is closed in effect simultaneously and the valve (4.1) leading to the storage tank (3) is reopened, whereby the blended material settles in the blending container (6) without being disturbed by turbulence in this control position and whereby this phase is maintained for a set period of time.Only at the end of that period of time is the line cross-section leading to the filter (8) opened to allow exhaust air to go through, and its passage is thereby adjusted so that the quantity of exhaust air going through the filter remains approximately constant per time unit.