Patent ID: 7540386

Claim:
A solids classifier for receiving an inlet flow stream comprising solids entrained in a gas and separating said solids into a first portion and a second portion based on the mass and/or density of said solids, said solids classifier comprising: a flow conduit defining an inlet opening for receiving said inlet flow stream and an outlet opening for discharging said first portion of said solids, wherein said outlet opening is located at a higher elevation than said inlet opening; a target at least partly received in said flow conduit and presenting a downwardly angled target face, wherein said flow conduit is configured to direct said inlet flow stream towards said target face; and a fluidized solids trap coupled to and extending generally downwardly from said flow conduit, wherein said solids trap is configured to receive said second portion of said solids; wherein said solids trap comprises a means for fluidizing at least a portion of said solids in said solids trap so that said second portion of said solids is retained in said trap while particles that are lighter and/or less dense than said particles of said second portion are forced out of and/or kept out of said solids trap; wherein said means for fluidizing comprises one or more fluidization gas inlets, wherein said solids trap further comprises a flow restriction element at least partly disposed above said fluidization gas inlets; wherein said flow restriction element comprises a conical fitting and/or a restrictive ring.