Closed cyclone FCC system with provisions for surge capacity

Claim 1

An apparatus for the fluid catalytic cracking of a hydrocarbon feed in a closed cyclone system comprising: (a) a reactor disengaging vessel containing a riser conversion zone, which is defined by a vertically disposed elongated tubular conduit having an upstream end and a downstream end, wherein said downstream end terminates within said reactor vessel; (b) means defining a radially extending restricted passageway having a first upstream end which includes an inlet communicating with said elongated tubular conduit at said downstream end of said tubular conduit and a second downstream end which includes means defining an opening on the bottom of said downstream end of said radially extending restricted passageway, said bottom opening adapted to discharge a stream of catalyst particles in a downward direction; (c) a cyclone separation means for separating entrained catalyst from gasiform material, for discharging separated catalyst into said reactor disengaging vessel, and for discharging said gasiform material externally to said disengaging vessel; (d) means defining an elongated catalyst stripping passageway positioned below and in open communication with the bottom opening of said radially extending restricted passageway and adapted to receive the catalyst particles into its upper end; (e) means defining a vertically disposed elongated restricted passageway surrounding said radially extending restricted passageway and said catalyst stripping passageway, said elongated restricted passageway being in direct fluid communication, at its upper end, with the inlet of said cyclone separation means and, at its lower end, with said catalyst stripping passageway; (f) a surge capacity means located on said elongated restricted passageway upstream of said cyclone separation means, wherein said surge capacity means accommodates a sudden increased rate of flow of said catalyst within said elongated restricted passageway, said surge capacity means being substantially closed during a normal rate of flow of said catalyst within said elongated restricted passageway thereby preventing catalyst flow therethrough but allowing stripping gas flow therethrough.

Claim 2

An apparatus for the fluid catalytic cracking of a hydrocarbon feed in a closed cyclone system comprising: (a) a reactor disengaging vessel containing a riser conversion zone, which is defined by a vertically disposed elongated tubular conduit having an upstream end and a downstream end, wherein said downstream end terminates within said reactor vessel; (b) means defining a radially extending restricted passageway having a first upstream end which includes an inlet communicating with said elongated tubular conduit at said downstream end of said tubular conduit and a second downstream end which includes means defining an opening on the bottom of said downstream end of said radially extending restricted passageway, said bottom opening adapted to discharge a stream of catalyst particles in a downward direction; (c) a cyclone separation means for separating entrained catalyst from gasiform material, for discharging separated catalyst into said reactor disengaging vessel, and for discharging said gasiform material externally to said disengaging vessel; (d) means defining an elongated catalyst stripping passageway positioned below and in open communication with the bottom opening of said radially extending restricted passageway and adapted to receive the catalyst particles into its upper end; (e) means defining a vertically disposed elongated restricted passageway surrounding said radially extending restricted passageway and said catalyst stripping passageway, said elongated restricted passageway being in direct fluid communication, at its upper end, with the inlet of said cyclone separation means and, at its lower end, with said catalyst stripping passageway; (f) a surge capacity means located on said elongated restricted passageway upstream of said cyclone separation means, wherein said surge capacity means accommodates a sudden increased rate of flow of said catalyst within said elongated restricted passageway, said surge capacity means being substantially closed during a normal rate of flow of said catalyst within said elongated restricted passageway thereby preventing catalyst flow therethrough but allowing stripping gas flow therethrough.

Claim 15

An apparatus for the fluid catalytic cracking of a hydrocarbon feed in a closed cyclone system comprising: (a) a reactor disengaging vessel containing a riser conversion zone, which is defined by a vertically disposed elongated tubular conduit having an upstream end and a downstream end, wherein the downstream end terminates within said reactor vessel; (b) means defining a radially extending restricted passageway having a first upstream end which includes an inlet communicating with said elongated tubular conduit at said downstream end of said tubular conduit and a second downstream end which includes means defining an opening on the bottom of the downstream end of said radially extending restricted passageway, said bottom opening adapted to discharge a stream of catalyst particles in a downward direction; (c) a cyclone for separating entrained catalyst from gasiform material, for discharging separated catalyst into said reactor disengaging vessel, and for discharging said gasiform material externally to said disengaging vessel; (d) means defining an elongated catalyst stripping passageway positioned below and in open communication with the bottom opening of said radially extending restricted passageway and adapted to receive the catalyst particles into its upper end; (e) means defining a vertically disposed elongated restricted passageway surrounding said radially extending restricted passageway and said catalyst stripping passageway, said elongated restricted passageway being in direct fluid communication, at its upper end, with the inlet of said cyclone separation means and, at its lower end, with said catalyst stripping passageway; (f) a surge capacity means comprising means defining an opening located on said elongated restricted passageway and a trickle valve for covering said elongated passageway opening, wherein a top portion of said trickle valve is pivotable about a trickle valve axis which is substantially perpendicular to the longitudinal axis of the riser, said surge capacity means accommodates a sudden increased rate of flow of said catalyst within said elongated passageway, said surge capacity means being upstream of said cyclone, said surge capacity means being substantially closed during normal catalyst flow through said elongated passageway thereby preventing catalyst flow through said elongated passageway opening; and (g) a serrated edge for horizontally elevating the bottom portion of said trickle valve with respect to said elongated restricted passageway when said trickle valve is in said substantially closed position, said serrated edge being attached to said elongated passageway, wherein said serrated edge allows a stripping gas to pass through said elongated passageway opening.

Claim 16

An apparatus for the fluid catalytic cracking of a hydrocarbon feed in a closed cyclone system comprising: (a) a reactor disengaging vessel containing a riser conversion zone, which is defined by a vertically disposed elongated tubular conduit having an upstream end and a downstream end, wherein the downstream end terminates within said reactor vessel; (b) means defining a radially extending restricted passageway having a first upstream end which includes an inlet communicating with said elongated tubular conduit at said downstream end of said tubular conduit and a second downstream end which includes means defining an opening on the bottom of the downstream end of said radially extending restricted passageway, said bottom opening adapted to discharge a stream of catalyst particles in a downward direction; (c) a cyclone for separating entrained catalyst from gasiform material, for discharging separated catalyst into said reactor disengaging vessel, and for discharging said gasiform material externally to said disengaging vessel; (d) means defining an elongated catalyst stripping passageway positioned below and in open communication with the bottom opening of said radially extending restricted passageway and adapted to receive the catalyst particles into its upper end; (e) means defining a vertically disposed elongated restricted passageway surrounding said radially extending restricted passageway and said catalyst stripping passageway, said elongated restricted passageway being in direct fluid communication, at its upper end, with the inlet of said cyclone separation means and, at its lower end, with said catalyst stripping passageway; (f) a surge capacity means comprising means defining an opening located on said elongated restricted passageway and a trickle valve for covering said elongated passageway opening, wherein a top portion of said trickle valve is pivotable about a trickle valve axis which is substantially perpendicular to the longitudinal axis of the riser, said surge capacity means accommodates a sudden increased rate of flow of said catalyst within said elongated passageway, said surge capacity means being upstream of said cyclone, said surge capacity means being substantially closed during normal catalyst flow through said elongated passageway thereby preventing catalyst flow through said elongated passageway opening; and (g) a serrated edge for horizontally elevating the bottom portion of said trickle valve with respect to said elongated restricted passageway when said trickle valve is in said substantially closed position, said serrated edge being attached to said elongated passageway, wherein said serrated edge allows a stripping gas to pass through said elongated passageway opening.