Patent ID: 7544333

Claim:
A device for fluidized bed cracking of a hydrocarbon charge, comprising: a first reaction chamber and a second reaction chamber, where the reaction chambers are linked together by a means for the transfer of cooling particles, and where the reaction chambers are fluidized bed cracking reactors, a regenerator providing regenerated catalytic particles to at least the first chamber, a stripping zone at the end of each reaction chamber to separate the catalytic particles from reaction effluents of each reaction chamber, a fractionating column having internally at least two different areas, a first fractionating area partitioned into a first and second compartment, each of which communicates with a second fractionating area, a first conduit and a second conduit, wherein the first and second conduits supply hydrocarbonated effluents from each of the two reaction chambers to said fractionating column, the first and second conduits terminate respectively in the first and second compartment of said first partitioned fractionating area, a means comprising at least a third conduit are provided for recycling and injecting into one of the reaction chambers, at least one cut of the reaction effluent from the other reaction chamber, drawn off from the first compartment the first partitioned area, said cut being rich in undesired product and, a fourth conduit is provided to remove cuts rich in undesired product drawn off from the second compartment of the first partitioned fractionating-area of the fractionating column.