Abstract: An in-line blending process for polymers comprising: (a) providing two or more reactor-low pressure separator units (1,7) in parallel configuration, each reactor-low pressure separator unit comprising one reactor (2,8) fluidly connected to one low pressure separator (3,9) downstream and further a recycling line (5,11) connecting the low pressure separator (3,9) back to the corresponding reactor (2,8); (b) polymerizing olefin monomers having two or more carbon atoms in each of the reactors (2,8) in solution polymerisation; (c) forming an unreduced reactor effluents stream including a homogenous fluid phase polymer-monomer-solvent mixture in each of the reactors (2,8), (d) passing the unreduced reactor effluents streams from each of the reactors (2,8) through the corresponding low pressure separators (3,9), whereby the temperature and pressure of the low pressure separators (3,9) is adjusted such that a liquid phase and a vapour phase are obtained, whereby yielding a polymer-enriched liquid phase and a polymer-

Abstract: An in-line blending process for polymers comprising: (a) providing two or more reactor-low pressure separator units (1,7) in parallel configuration, each reactor-low pressure separator unit comprising one reactor (2,8) fluidly connected to one low pressure separator (3,9) downstream and further a recycling line (5,11) connecting the low pressure separator (3,9) back to the corresponding reactor (2,8); (b) polymerizing olefm monomers having two or more carbon atoms in each of the reactors (2,8) in soltion polymerisation; (c) forming an unreduced reactor effluents stream including a homogenous fluid phase polymer-monomer-solvent mixture in each of the reactors (2,8), (d) passing the unreduced reactor effluents streams from each of the reactors (2,8) through the corresponding low pressure separators (3,9), whereby the temperature and pressure of the low pressure separators (3,9) is adjusted such that a liquid phase and a vapour phase are obtained, whereby yielding a polymer-enriched liquid phase and a polymer-le

Abstract: A method and apparatus for taking a sample from a flowing suspension formed by polymer particles and hydrocarbon diluent in a olefin polymerization process including at least one filter situated at a plane of an inside surface of a transfer conduit between reactors. Each filter includes perforations or pores having a size to prevent substantially any of the catalyst used in the polymerization process from passing through the filter, e.g., smaller than the smallest particle size of a catalyst used in the polymerization process. The pore or perforation size of each filter is preferably 0.1-10 .mu.m, preferably between 0.2-1 .mu.m. A pressure difference permits at least partial vaporization of the sample as it passes through the filter.

Abstract: A process for producing polyethylene compositions in the presence of a catalytic system of ethylene polymerizing catalyst and cocatalyst in a multistage continuous reaction sequence consisting of successive liquid phase and gas phase polymerizations is disclosed. In the first step of the process, ethylene and optionally hydrogen and comonomer are polymerized in a first loop reactor in a low boiling hydrocarbon medium in the presence of ethylene polymerizing catalyst and cocatalyst. The reaction mixture is then removed and then transferred to a second loop reactor where polymerization is continued by addiing ethylene, hydrogen and optionally inert hydrocarbon, comonomers and cocatalysts. Thereafter, the reaction mixture is removed from the second loop reactor along with an essential part of the reaction medium and transferred to a gas phase reactor where polymerizing is continued in the presence of added ethylene and optionally hydrogen, comonomers and cocatalysts to form an end product.

Abstract: A fluidized bed polymerization process in which a central mixing element sweeps the interior of the bed. The mixing element contains agitator arm which pass adjacent to the reactor walls and a have a perforated surface. Gas is directed to the central mixing shaft and distributed to the agitator arms.

Abstract: The invention concerns a method and an equipment for taking a sample in slurry polymerization. The sample is taken directly from the liquid phase of the reactor (15) through an in-line filter (40). The slurry flow is maintained in the in-line filter (40) at a sufficiently hight level to prevent immobilization of polymer or catalyst particles on the filter face of the in-line filte (40).

Abstract: The invention concerns a multi-stage process for producing polyethylene having a bimodal and/or broad molecular weight distribution in the presence of an ethylene polymerizing catalyst system in a multistep reaction sequence, in which the first reaction step is a liquid phase polymerization step and the second reaction step is formed by one or more gas-phase polymerization steps. According to the process of the invention in the first reaction step ethylene is polymerized in a loop reactor (10) in an inert low-boiling hydrocarbon medium the residence time being at least 10 minutes, reaction mixture is discharged from the loop reactor (10) and at least a substantial part of the inert hydrocarbon mixture is separated and the polymer is transferred into one or more gas-phase reactors (30), where the polymerization is completed in the presence of ethylene and optionally hydrogen and a comonomer.

Abstract: The invention relates to a regulation method for regulating the temperature in a reactor utilized in the polymerization of olefines. A circulating gas is led to the reactor along a circulating gas flow line, and the circulating gas is cooled by leading part of the circulating gas flowing along a circulating gas flow line along a by-pass flow line through a cooler. A regulating device for the circulating gas inlet-flow temperature controls the amount of the circulating gas by-pass flow along a circulating gas by-pass flow line through the cooler such that the sum of the openings of a valve in the circulating gas flow line and a valve in the circulating gas by-pass flow line is maintained substantially constant in the range from about 90 to about 120%.

Abstract: The invention relates to a method and device for feeding a mud-like catalyst mixture into a polymerization reactor. The catalyst mixture is fed from a container into a batching space of a feeder connected thereto, from which channel the catalyst mixture is further fed by batches into the polymerization reactor by the use of the pressure of a medium fed into the feeder. In accordance with the invention, after each catalyst batch fed into the polymerization reactor, the medium is substantially removed from the batching space of the feeder by leading the medium via an outlet channel into a space between two on/off valves before filling the batching space with a new catalyst batch.

Abstract: The invention relates to a method and an apparatus for continuously taking a sample from a discharge system of a polymerization reactor having a discontinuously opening discharge valve connecting the polymerization reactor to a product tube leading into a solid-constituent separation system. A sampling means having a closing valve of an on/off type is connected to the product tube. The closing valve closes for the period of a pressure wave occurring when the discharge valve opens, and opens after the pressure wave. A buffer container connected to an analyzer is provided with a sufficient volume to maintain the continuity of the sample flow when the closing valve is closed.