摘要:
A process for continuously mixing at least two fluid streams and splitting the stream of the mixture into at least two partial streams, comprising a) providing streams of the at least two fluids via separated conduits; b) combining the streams of the fluids and forming a homogeneous mixture; c) measuring the pressure in the conduit conveying the mixture of the fluids; d) splitting the stream of the mixture of the fluids into at least two partial streams and feeding each of the partial streams to a conduit equipped with a flow control device controlled by a controller; and e) adjusting the flow rates of the partial streams of the mixture of the fluids by feeding the pressure information measured in step c) as process variable to the controllers controlling the flow control devices, a process for feeding a mixture of at least two fluids via at least two feeding points, an apparatuses for carrying out such processes and a process for polymerizing olefins.
摘要:
A process for continuously mixing at least two fluid streams and splitting the stream of the mixture into at least two partial streams, comprising a) providing streams of the at least two fluids via separated conduits; b) combining the streams of the fluids and forming a homogeneous mixture; c) measuring the pressure in the conduit conveying the mixture of the fluids; d) splitting the stream of the mixture of the fluids into at least two partial streams and feeding each of the partial streams to a conduit equipped with a flow control device controlled by a controller; and e) adjusting the flow rates of the partial streams of the mixture of the fluids by feeding the pressure information measured in step c) as process variable to the controllers controlling the flow control devices, a process for feeding a mixture of at least two fluids via at least two feeding points, an apparatuses for carrying out such processes and a process for polymerizing olefins.
摘要:
Process for discharging polyolefin particles from a gas-phase polymerization reactor of a pressure from 1.0 MPa to 10 MPa to a discharge vessel of a pressure from 0.1 MPa to 1.0 MPa wherein the discharging is carried out discontinuously through at least two discharge lines in which the polyolefin particles are transported horizontally or upwards, process for polymerizing olefins at temperatures of from 30° C. to 160° C. and pressures of from 1.0 MPa to 10 MPa in the presence of a polymerization catalyst in a gas-phase polymerization reactor comprising discharging the obtained polyolefin particles from the gas-phase polymerization reactor by the process for discharging polyolefin particles and apparatus for polymerizing olefins in the gas-phase comprising a polymerization reactor, a discharge vessel and at least two pipes connecting the polymerization reactor and the discharge vessel for discharging polyolefin particles, wherein the discharge lines are constructed in a way that the polyolefin particles conveyed from the polymerization reactor to the discharge vessel are transported horizontally or upwards.
摘要:
A continuous gas-phase process for the polymerization of alpha-olefins, in particular ethylene, comprising passing an alpha-olefin monomer stream through an oil filter in order to reduce the amount of oil to less than 8 ppm, and polymerizing the thus purified monomer feed in gas-phase reactor; the reduction of the amount of oil improves the operability of the plant over time.
摘要:
A continuous gas-phase process for the polymerization of alpha-olefins, in particular ethylene, comprising passing an alpha-olefin monomer stream through an oil filter in order to reduce the amount of oil to less than 8 ppm, and polymerizing the thus purified monomer feed in gas-phase reactor; the reduction of the amount of oil improves the operability of the plant over time.
摘要:
Process and apparatus for discharging polyolefin particles from a gas-phase polymerization reactor of a pressure from 1.0 MPa to 10 MPa to a discharge vessel of a pressure from 0.1 MPa to 1.0 MPa wherein the discharging is carried out discontinuously through at least two discharge lines in which the polyolefin particles are transported horizontally or upwards.
摘要:
A polyethylene composition, in particular suitable for the preparation of films, and a process for preparing the same are described. The polyethylene composition of the invention comprises from 50 to 89% by weight of a first polyethylene component comprising at least one multimodal polyethylene including a plurality of ethylene polymer fractions having distinct molecular weights and comonomer contents, at least one of said plurality of ethylene polymer fractions being prepared by the use of a single site catalyst, and from 50 to 11% by weight of a second polyethylene component comprising a low or medium density polyethylene.
摘要:
Process for preparation of ethylene homopolymers or copolymers, comprising the steps of a) polymerization of ethylene or of ethylene with one or more other 1-olefins in the presence of a chromium catalyst at temperatures of from 20 to 200° C. and at pressures of from 0.1 to 20 MPa, where the chromium catalyst can be prepared via application of one or more chromium compounds to a silicate support and subsequent thermal activation under oxidative conditions at temperatures of from 620 to 900° C.; b) mixing of the polyethylene in the melt in the presence of from 1000 to 2000 ppm of an antioxidant comprising at least one sterically hindered phenol and comprising at least one phosphite in a mixing ratio of from 1:5 to 5:1, with specific energy input of at least 0.17 kWh/kg.
摘要:
Apparatus for the polymerization of olefins, in particular ethylene, comprising a gas-phase fluidized-bed reactor (1), a product offtake line (15) for taking polymer particles either continuously or discontinuously from the reactor (1), which line (15) is connected to a depressurization vessel (2) for separating polymer particles and gas, a recycle gas filter (3) for freeing the gas of entrained fine particles connected to the depressurization vessel (2), a compressor which compresses the gas which has been freed of fine particles and recirculates it into the reactor (1), with the recycle gas filter (3) having an inlet chamber (4) provided with a gas inlet (6), an outlet chamber (5) provided with a gas outlet (7), an essentially vertical sheet-like filter medium (9) for retaining the fine particles which separates the inlet chamber (4) from the outlet chamber (5) and a particle outlet (8). The inlet chamber (4) has a dividing wall (10) which is arranged essentially parallel to the filter medium (9) and separates the inlet chamber (4) into an inflow region (4a), which is connected to the gas inlet (6), and a filter region (4b) in which the filter medium is located and has an upper opening and a lower opening which are dimensioned so that from 60 to 90% of the volume flow flows through the upper opening so that flow along the filter medium (9) from the top downward results.