Separation of solid polymers and liquid diluent

Claim 1

In a process wherein mono-1-olefin having 2 to 8 carbon atoms per molecule is polymerized in a continuous loop polymerization reactor in a liquid diluent in the presence of a suitable polymerization catalyst under such conditions that substantially all of the polymer produced is insoluble in the diluent and is in the form of solid particles of polymer wherein a slurry of said polymer solids and diluent is accumulated in a settling leg of said loop reactor, an improved method for separating the polymer solids and the diluent comprising shutting off communication between the reaction zone of said loop reactor and said settling leg when the desired level of solids have accumulated in the settling leg, passing the accumulated polymer-diluent slurry located in the settling leg to a filter vessel, filtering polymer solids from the liquid diluent in the filter vessel under pressure conditions such that the major portion of the liquid diluent from the settling leg remains in the liquid phase.