Abstract: In order to specify a method, which is improved in comparison to the prior art, for monitoring an electrical switching arrangement having at least two channels, which each electrically conductively connect an electrical source supplying the respective channel, forming an electrical supply quantity, to an output of the respective channel, the switching arrangement is fed not only an external safety signal, from which an internal safety signal is respectively generated for the at least two channels in order to therewith control a voltage interrupter connected in series in the respective channel, but also a pulsed diagnostic signal, which is superimposed on the internal safety signals in order to alternately open and close again the voltage interrupters connected in the respective channels and to thus respectively alternately interrupt the supply quantities appearing in the respective channels.

Abstract: In order to specify a method, which is improved in comparison to the prior art, for monitoring an electrical switching arrangement having at least two channels, which each electrically conductively connect an electrical source supplying the respective channel, forming an electrical supply quantity, to an output of the respective channel, the switching arrangement is fed not only an external safety signal, from which an internal safety signal is respectively generated for the at least two channels in order to therewith control a voltage interrupter connected in series in the respective channel, but also a pulsed diagnostic signal, which is superimposed on the internal safety signals in order to alternately open and close again the voltage interrupters connected in the respective channels and to thus respectively alternately interrupt the supply quantities appearing in the respective channels.

Abstract: A method for the analysis by on-line gas phase chromatography of a gaseous phase produced by an olefin polymerization process which includes carrying out a chromatographic analysis of a gaseous phase produced by an olefin polymerization process with carrier gases containing mainly hydrogen and/or nitrogen, wherein the content of oxygen and of water of the hydrogen and the nitrogen in the carrier gases is less than 5 ppm by weight.

Abstract: A process for the continuous gas-phase (co-)polymerisation of olefins in a fluidised bed reactor using a Ziegler-Nata type catalyst wherein the polymerisation is performed in the presence of a process aid additive selected from at least one of (1) a polysulphone copolymer; (2) a polymeric polyamine or (3) an oil-soluble sulphonic acid.

Abstract: A process for the continuous gas-phase (co-)polymerization of olefins in a fluidized bed reactor using a Ziegler-Natta type catalyst. The polymerization is performed in the presence of a process aid additive.

Abstract: A process for the gas phase polymerization of one or more alpha-olefins conducted in the presence of a catalyst in a reactor having a fluidized bed, in which process, one or more zones having a temperature greater than the average bed temperature are formed at or in close proximity to the reactor wall, comprising the step of deactivating said zones by the introduction into the reactor of an effective quantity of carbon monoxide.

Abstract: A process for starting up a reaction for the polymerization of an olefin in the gas phase carried out using a catalyst based on chromium oxide in a fluidized bed reactor through which moves a reaction gas mixture containing the olefin, wherein in the start-up of the reaction, the olefin is introduced into the reactor until the desired production of polymer is reached by means of a two-stage process, during the first stage of which the introduction of the olefin is carried out so as to maintain a constant partial pressure of olefin in the reactor and during the second stage, the introduction of olefin is regulated at a constant flow rate.

Abstract: The subject-matter of the present invention is thus a process for starting up a gas phase olefin polymerisation reaction carried out using a Ziegler-Natta type catalyst based on a transition metal in a fluidized-bed reactor, through which passes a reaction gas mixture comprising the olefin, an inert gas, hydrogen and optionally at least one comonomer and which operates under conditions of temperature and pressure which make it possible to start up the polymerization, characterized in that the partial pressure of the olefin and the rate of introduction of catalyst into the reactor are increased whilst maintaining the ratios of the partial pressures of the olefin to the hydrogen and to the optional comonomer or comonomers substantially constant.