Abstract: Method and apparatus for thermally processing polyester pellets, e.g., polyethylene terephthalate pellets, in order to achieve a partial crystallization, whereby the polyester melt is fed to an underwater pelletizer and pelletized, the pellets obtained are fed to a water/solids separating device and the dried pellets are fed at a pellet temperature of greater than 100°C. to an agitation device that the pellets leave at a pellet temperature of over 100°C.

Abstract: Process and apparatus are described for adsorptive bubble separation of hydrophobic particles from liquid dispersions. The process may be used to treat the gas/liquid dispersion after it has been introduced from two or more ducts near the perimeter or from a central duct of the separation vessel. When the gas-liquid-particle dispersion is introduced from a central duct, the rising bubbles are directed by, e.g., a baffle toward the perimeter of the apparatus, where they rise. At the liquid surface, bubbles with attached hydrophobic materials form a floating froth layer, which is directed toward a central froth collection launder. Rising froth at the perimeter pushing the froth bed into the reduced area of the center encourages further coalescence of the bubbles and increases liquid drainage from the froth, thus leading to concentration of the collected materials without the need for complex equipment geometry.

Abstract: A method of concentrating particles in a liquid-particle dispersion feed by adsorptive bubble separation by intimately contacting a gas with a pressurized stream of liquid in a chamber to form an aerated dispersion that retains at least some of the kinetic energy from the pressurized stream, and removing at least some of the kinetic energy from the aerated dispersion to form a dense foam. A liquid-particle dispersion feed is then injected into the dense foam to form a gas-liquid-particle dispersion. The gas-liquid-particle dispersion is injected into a flotation chamber at a point below a surface of a liquid contained therein, where the gas-liquid-particle dispersion forms bubbles of a gas-particle agglomerate, and the bubbles are released from the feed liquid depleted in hydrophobic particles and rise to the surface to form a floating froth enriched in particles.

Abstract: A method for preventing or reducing clogging of a fines ejector in a gas-phase olefin polymerization process is disclosed. The process involves injecting a liquid into the motive gas stream entering the fines ejector.

Abstract: A process for preventing or reducing polymer agglomeration and/or accumulation on or around the gas distribution grid in an olefin polymerization, fluidized-bed reactor. The process involves introducing one or more scouring balls into the reactor above the gas distribution grid, and carrying out olefin polymerization in the presence of the scouring balls. Also disclosed is a process for polymerizing olefins in a fluidized-bed reactor with reduced polymer agglomeration and/or accumulation on the gas distribution grid.

Abstract: A method for preventing or reducing agglomeration and/or accumulation on or around the gas distribution grid in a fluidized-bed vessel. The method involves introducing one or more scouring balls into the vessel above the gas distribution grid, and carrying out a fluidized-bed process in the presence of the scouring balls.

Abstract: A streamer trap assembly for collecting streamers from a flow of polymer pellets includes a housing comprising an inlet, an outlet, and an opening bounded by a sealing surface; and a streamer trap positioned in the housing through the opening. The streamer trap comprises a screen sized to collect the streamers at the screen and to allow the polymer pellets to pass through the screen, a guide positioned to guide the flow of polymer pellets from the inlet to the screen and from the screen to the outlet, and a cover adapted to engage the sealing surface and cover the opening.

Abstract: There are disclosed polymerization processes and associated apparatuses. The polymerization processes involve both making a polymeric material in a fluidized bed reactor having a feed distributor and catching a spitwad with a spitwad catcher, and the apparatuses are those corresponding to such processes.

Abstract: There are disclosed polymerization processes and associated apparatuses. The polymerization processes involve both making a polymeric material in a fluidized bed reactor having a feed distributor and catching a spitwad with a spitwad catcher, and the apparatuses are those corresponding to such processes.

Abstract: A process and apparatus for gas phase polymerization of olefins in a fluidized bed reactor are disclosed. The process and apparatus employ a vertically oriented fines ejector in order to reduce fouling and reactor downtime.

Abstract: A gas distribution plate for fluidized-bed, olefin polymerization reactors is provided. In addition to holes for distributing a fluidizing gas, the plate comprises a plurality of hollow projections for introducing a fluid into the fluidized-bed reactor. The hollow projections, which can be tubes or pipes, extend above the plate towards the fluidized bed and serve a number of purposes. The projections can break apart or penetrate fallen polymer agglomerates or sheets. They can be equipped with flow or pressure sensors to detect a decrease in flow rate or an increase in pressure drop across the projections, which is an indicator of the presence and/or size of fallen polymer agglomerates or sheets. The projections can also break apart the agglomerates or sheets into smaller pieces by delivering blasts of fluid directly into the agglomerates or sheets.

Abstract: A novel process for the polymerization of olefins is provided. The process involves contacting at least one olefin with a Ziegler-Natta type catalyst in the presence of a specified compound that results in the production of polymeric products having a narrower molecular weight distribution. Also provide is a process for narrowing the molecular weight distribution of a polyolefin comprising contacting an olefin, a Ziegler-Natta catalyst and a compound specified herein. Further provided are novel polyethylenes, and films and articles produced therefrom.

Abstract: A high-pressure separator with improved efficiency is provided. The separator comprises a centrifugal separator located inside of a gravity separator. The centrifugal separator has an enclosed upper portion and desirably comprises a single cylinder. The high-pressure separator is particularly suitable for use in the production of low-density polyethylene under high pressure.

Abstract: A process and apparatus for gas phase polymerization of olefins in a fluidized bed reactor are disclosed. The process and apparatus employ a vertically oriented fines ejector in order to reduce fouling and reactor downtime.

Abstract: A novel process for the polymerization of olefins is provided. The process involves contacting at least one olefin with a Ziegler-Natta type catalyst in the presence of a specified compound that results in the production of polymeric products having a narrower molecular weight distribution. Also provide is a process for narrowing the molecular weight distribution of a polyolefin comprising contacting an olefin, a Ziegler-Natta catalyst and a compound specified herein. Further provided are novel polyethylenes, and films and articles produced therefrom.

Abstract: A method for polymerizing olefins in a fluidized-bed reactor is provided. The method involves introducing a fluid into the fluidized-bed reactor at an angle and amount sufficient to induce one or more swirls in the fluidized bed in the reactor.

Abstract: A modified asphalt composition is provided comprising at least one plastomer, at least one elastomer, and asphalt. More specifically, a modified asphalt composition is provided comprising an oxidized polyethylene, a styrene-butadiene-styrene block copolymer, and asphalt. A hot mix asphalt composition is also provided comprising the modified asphalt composition and aggregate. Processes for producing the modified asphalt composition and the hot mix asphalt composition is also provided as well as articles produced from these inventive compositions.

Abstract: A modified asphalt composition is provided comprising at least one plastomer, at least one elastomer, and asphalt. More specifically, a modified asphalt composition is provided comprising an oxidized polyethylene, a styrene-butadiene-styrene block copolymer, and asphalt. A hot mix asphalt composition is also provided comprising the modified asphalt composition and aggregate. Processes for producing the modified asphalt composition and the hot mix asphalt composition is also provided as well as articles produced from these inventive compositions.

Abstract: A modified asphalt composition is provided comprising at least one plastomer, at least one elastomer, at least one crosslinking agent and asphalt. More specifically, a modified asphalt composition is provided comprising an oxidized polyethylene, a styrene-butadiene-styrene block copolymer, sulfur, and asphalt. A hot mix asphalt composition is also provided comprising the modified asphalt composition and aggregate. Processes for producing the modified asphalt composition and the hot mix asphalt composition are also provided as well as articles produced from these inventive compositions.