Patent ID: 6846463

Claim:
An apparatus comprising: (i) a vertical primary cyclone vessel having a tubular housing comprising a tubular wall section provided with a tangentially arranged inlet that is fluidly connected to a reactor riser of a fluidized catalytic cracking process and which provides for receiving a suspension of catalyst particles and hydrocarbon vapor from said reactor riser, and which tubular wall section is open at its lower end and closed at its upper end by means of a cover provided with an opening, wherein the opening is fluidly connected to a gas outlet conduit, which conduit has a gas inlet opening located at the same level as the opening in the cover; (ii) one or more secondary gas-solids separator means which are fluidly connected with the gas outlet conduit of the primary cyclone; wherein the gas inlet opening of the gas outlet conduit is located at a distance (d1) above the center of the tangentially arranged inlet opening and wherein the ratio of this distance and the diameter of the tubular housing (d2) is between about 0.2 and 3.