초록 ▼

An FCC feed distributor mixes fresh catalyst entering the riser with steam to cream a dense bubbling bed of catalyst. Fluidized catalyst rises from the dense bed around a conical section supported from the bottom of the riser. The conical section accelerates the catalyst by reducing the flow area in

An FCC feed distributor mixes fresh catalyst entering the riser with steam to cream a dense bubbling bed of catalyst. Fluidized catalyst rises from the dense bed around a conical section supported from the bottom of the riser. The conical section accelerates the catalyst by reducing the flow area into a small width annulus. As fast fluidized catalyst flows to the annulus, a diverter outwardly redirects an axially flowing feed stream to discharge feed radially into the catalyst as it flows by the annular section. A narrow width of the annular section provides good penetration of the catalyst stream by the feed to quickly and completely mix the catalyst and feed. A tapered conical section above the narrow annular section provides an extended region of gradually increasing flow area that controls downstream acceleration of the gas and catalyst mixture by permitting expansion and preventing back mixing over the initial stages of the cracking reaction. This arrangement improves the uniformity of gas and catalyst contacting while reducing the amount of steam or other dispersion gas required to achieve good catalyst and feed contact.

대표청구항 ▼

A method of mixing fluidized particles with a fluid feed stream comprising hydrocarbons, said method comprising: a) combining fluidized particles and a fluidizing medium in an upstream section of a riser conduit to produce a dense bed of catalyst; b) passing said dense bed of catalyst downstream thr

A method of mixing fluidized particles with a fluid feed stream comprising hydrocarbons, said method comprising: a) combining fluidized particles and a fluidizing medium in an upstream section of a riser conduit to produce a dense bed of catalyst; b) passing said dense bed of catalyst downstream through said riser conduit into a feed contact zone having a reduced cross sectional area relative to said upstream section; c) passing a fluid feed stream longitudinally through a feed conduit; d) redirecting said fluid feed at a downstream end of said feed conduit to flow in a radial direction by contact with a flow diverter and discharging said fluid feed stream radially through an extended circumferential port into said feed contact zone to produce a mixture of feed and catalyst; e) accelerating said mixture of feed and catalyst in a downstream direction in said riser conduit through an acceleration zone, said acceleration zone having a continuously increasing cross sectional area; and, f) passing said mixture of feed and catalyst from said acceleration zone into a section of said riser conduit having a uniform cross sectional area.