Bp Chemicals Limited

Ineos Europe Ag

Ineos Sales (uk) Limited

Gary Pitman

Kevin Ramsay

Gerald Mulgrew

Method for treating a heat exchanger which in operation is used to cool process water which has been in contact with polymer particles. The method includes passing to the process side of the heat exchanger a treatment stream while the heat exchanger is at an elevated temperature compared to the temperature when the heat exchanger is in operation.

Method of cleaning a heat exchanger

Process for extrusion of polymer by feeding a polymer feedstock to the feed port of an extruder having (i) two or more barrel sections arranged sequentially from (a) an upstream feed barrel section to which polymer feedstock to be extruded is fed, the upstream feed barrel section containing two screws each having a diameter of X, to (b) a downstream barrel section from which melted polymer is passed to a die and extruded, and (ii) a feed port for feeding polymer feedstock to be extruded into the extruder at its upstream end. The polymer feedstock is in the form of a powder, and the feed port area is a rectangular shape with width limited by the width of the upstream feed barrel section to 2*X and with a length greater than 2.5*X. The total area of the feed ports through which polymer feedstock is introduced is greater than 5*X.

Extruder and process for extruding a polymer

A process for the separation of volatile material from particulate polymer which has been substantially freed from unreacted monomer in an earlier separation step, comprising (a) feeding the particulate polymer to a purge vessel, optionally causing it to move through the vessel in substantially plug-flow mode, (b) heating the particulate polymer in the purge vessel to a temperature greater than 30&#xb0; C. but insufficiently high to cause the particles to become agglomerated, and/or maintaining the polymer at a temperature in this range in the purge vessel, (c) feeding air to the purge vessel counter-current to the movement of the particulate polymer to remove volatile material therefrom, (d) removing the particulate polymer from the purge vessel. Preferably the particulate polymer fed to the purge vessel is caused to move through the vessel in substantially plug-flow mode. The process is particularly suitable for polyethylene.

Growing community of inventors

Stirling, United Kingdom

Gary Pitman