Patent ID: 7727385
Filing Date: 2010-06-01
Classification: B03B,B03D,C10G

Abstract:
1. A method for continuously recovering bitumen as froth from a feed stream having solids, water and bitumen, comprising: (a) delivering the feed stream into a separating vessel through a feedwell and allowing the feed stream to separate into an upper bitumen-rich zone, a middlings zone and a lower concentrated solids zone; (b) providing a downpipe assembly comprising at least one downpipe having an upper end and an open lower end, said downpipe assembly mounted to the separation vessel such that each downpipe extends substantially vertically into the separation vessel and the open lower end of each downpipe extends below the bitumen-rich zone; (c) removing a stream of middlings from the middlings zone of the separation vessel and introducing the middlings stream into a nozzle positioned at or near the upper end of each downpipe and in fluid communication with the downpipe to form a jet of middlings; (d) introducing air into the middlings stream to produce aerated middlings and allowing the aerated middlings to issue from the open lower end of each downpipe below the bitumen-rich zone of the separation vessel; and (e) continuously recovering the bitumen froth from the upper bitumen-rich zone and withdrawing the solids from the lower concentrated solids zone in the separation vessel.