Mitsui Chemicals, Inc.

Mitsui Petrochemical Industries, Ltd.

Yoshiaki Kikuchi

Satoru Ohtani

Ryoichi Yamamoto

Tomohiro Arase

Shotaro Matsuda

Ryouichi Yamamoto

Toshihiro Okano

Fumio Hattori

Hisayoshi Watanabe

Jun Iwama

Kenji Doi

Mitsunori Ichimura

Takao Uetake

In a gas phase olefin polymerization process using a fluidized bed vessel, an apparatus is employed having a device for measuring temperature or temperature distribution on the external wall surface of the vessel and a controlling means which predicts the progressive state of reaction inside the vessel, calculates the difference between the measured value and a target value determined beforehand and modifies polymerization conditions in relation thereto.

Fluidized bed polymerization apparatus and an olefin polymerization process

In a gas phase olefin polymerization process using a fluidized bed vessel, an apparatus is employed having a device for measuring temperature or temperature distribution on the external wall surface of the vessel and a controlling means which predicts the progressive state of reaction inside the vessel, calculates the difference between the measured value and a target value determined beforehand an modifies polymerization conditions.

Fluidized bed polymerization apparatus having temperature distribution monitoring

A method of multistage gas phase polymerization is provided comprising performing polymerization of a feed gas mixture at least containing ethylene gas, an &agr;-olefin gas and hydrogen gas in an upstream fluid bed reactor to thereby produce a polymer powder, recovering the thus-produced polymer powder and performing further polymerization of the polymer powder in a downstream fluid bed reactor, the downstream fluid bed reactor being continuously connected to the upstream fluid bed reactor so that the polymer powder recovered from the upstream fluid bed reactor is introduced into the downstream fluid bed reactor, which method comprises the steps of: recovering polymer powder from the upstream fluid bed reactor, treating the recovered polymer powder so as to lower the content of &agr;-olefin gas and hydrogen gas therein by contacting the polymer powder with a stream of gas comprising ethylene or an inert gas, and introducing the treated polymer powder into the downstream fluid bed reactor. By this method, &agr;-olefin gas and hydrogen gas which inhibit the polymerization reaction in the downstream fluid bed reactor and which render regulation of desired polymer product properties difficult are removed from the polymer product prior to the downstream fluid bed reactor.

Method of multistage gas phase polymerization, apparatus therefor and device for reducing entrainment of subcomponents in polymer powder in apparatus for multistage gas phase polymerization

A method for vapor phase polymerization comprises blowing a gaseous monomer from a bottom of a fluidized bed reactor through a distributor plate into the reactor by means of a blower while feeding a solid catalyst into the reactor to thereby form a fluidized bed in the reactor and conducting a vapor phase polymerization to produce a polymer or copolymer, wherein the blower has a slide or rotational slide part between its discharge side as a high pressure side and its suction side as a low pressure side in a blower body casing, said slide or rotational slide part being provided with a noncontacted gas leakproof seal part at a clearance ranging from 0.7 to 2.5 mm.

Method of vapor phase polymerization, vapor phase polymerizer and blower

A gas distributor plate provided in a fluidized bed polymerization vessel which effects the gas phase polymerization of olefins, the gas distributor plate exhibiting excellent action for uniformly diffusing the gas flow in the fluidized bed zone. A gas distributor plate has a number of gas passage holes and is provided in a fluidized bed polymerization vessel which effects the gas phase polymerization of olefins, wherein when the inner radius of the straight drum portion of the polymerization vessel is denoted by 1, the holes perforated in the outer peripheral portion of the distributor plate at 0.7 to 1.0 from the center of the straight drum portion have an average diameter which is larger than the average diameter of the holes perforated in the inner peripheral portion of the distributor plate at smaller than 0.7 from said center. This makes it possible to uniformly and stably diffuse the gas flow in the fluidized bed zone in the polymerization vessel, to effectively prevent the formation of a dead zone, as well as to effectively prevent the polymer from adhering onto the wall surfaces of the polymerization vessel.

Gas distributor plate for a gas phase polymerization apparatus

A rotor 22 accommodated in a casing 26 has a circumferential surface sliding on the internal surface of the casing 26 in airtight condition. The casing 26 is provided with a powder feed part 27 positioned above the rotor and is provided with a powder drop part 30 positioned under the rotor. At least one quantity-measuring recessed part is formed in the slide surface of the rotor. In accordance with the rotation of the rotor, the quantity-measuring recessed part comes to communicate with the powder feed part, so that powder is fed from the powder feed part into the quantity-measuring recessed part. When the rotation is advanced, the quantity-measuring recessed part comes to communicate with the powder drop part, so that the powder drops from the quantity-measuring recessed part through the powder drop part into a high-pressure part 19 arranged thereunder. These members construct a quantitative powder feeder which, even when a pressure difference exists between the supply side and the supplied side, can effectively prevent the gas flow and pressure leak therebetween and can minimize the amount of carrier gas used for feeding powder.

Growing community of inventors

Ichihara, Japan

Yoshiaki Kikuchi