Abstract: Process for transferring a slurry stream containing polymer through a transfer line from a polymerisation reactor to a downstream vessel by, prior to entry into the downstream vessel, separating the slurry stream into two flows, the first flow being recycled upstream of the flow separation and the second flow being passed into the downstream vessel. The flow separation is located more than halfway along the transfer line between the reactor and the downstream vessel.

Abstract: A process for transferring a slurry stream containing polymer through a transfer line from a first polymerisation reactor to a second polymerisation reactor is disclosed, wherein prior to entry from the transfer line into the second polymerisation reactor, the slurry stream is separated into two flows and the first flow is returned to the first reactor whilst the second flow passes into the second reactor, the length of the transfer line between the first reactor and the location of the flow separation being more than that between the second reactor and the location of the flow separation.

Abstract: Olefin polymerisation process in which a slurry of olefin polymer is produced within a polymerisation zone, followed by withdrawing a polymer slurry stream from the polymerisation zone, and passing the polymer slurry stream through a transfer line to a centrifugal concentrating device which separates the polymer slurry stream into a solids-lean stream or streams each having a solids concentration less than that of the polymer slurry stream entering the concentrating device and a solids-rich stream or streams each having a solids concentration greater than that of the polymer slurry stream entering the concentrating device. At least part of the solids-rich stream or streams is recycled back into the polymer slurry stream upstream of the concentrating device and downstream of the polymerisation zone, and 2-60 vol % of the solids-rich slurry stream is recycled back into the polymer slurry stream upstream of the concentrating device.

Abstract: An olefin polymerisation process is disclosed in which a slurry of olefin polymer is produced within a polymerisation zone, and a polymer slurry stream is withdrawn from the polymerisation zone and passed through a transfer line to a centrifugal concentrating device, which separates it into a solids-lean stream or streams each having a solids concentration less than that of the polymer slurry stream entering the concentrating device and a solids-rich stream or streams each having a solids concentration greater than that of the polymer slurry stream entering the concentrating device, wherein at least part of the solids-rich stream or streams is recycled back into the polymer slurry stream upstream of the concentrating device and downstream of the polymerisation zone.