초록

A novel apparatus and process, including a perforated-pipe sparger, for atomizing a liquid stream is disclosed. This novel apparatus and process can be utilized in a fluidized catalytic cracking process or in a coking process for atomizing an oil stream prior to contact with a fluidized catalyst.

대표청구항 ▼

[ That which is claimed is:] [1.] An atomizer comprising:a first conduit having a longitudinal axis, an inside wall, an inside diameter D.sub.1, an upstream end portion, a downstream end portion, and an opening in said inside wall intermediate said upstream end portion and said downstream end portio

[ That which is claimed is:] [1.] An atomizer comprising:a first conduit having a longitudinal axis, an inside wall, an inside diameter D.sub.1, an upstream end portion, a downstream end portion, and an opening in said inside wall intermediate said upstream end portion and said downstream end portion;a second conduit having a perforated-pipe sparger at one end thereof for introducing an atomizing enhancing medium to said first conduit; said perforated-pipe sparger having a longitudinal axis and being disposed within said first conduit through said opening in said inside wall with the longitudinal axis of said perforated-pipe sparger being in a generally perpendicular relation to the longitudinal axis of said first conduit; said perforated-pipe sparger having an outside surface, a first end, a closed second end, an outside diameter D.sub.2, a length L.sub.1 within said first conduit and a plurality of holes facing generally in the direction of the downstream end portion of said first conduit; the outside surface at said first end of said perforated-pipe sparger being in sealing engagement with said opening in said inside wall of said first conduit; anda third conduit having an inside diameter D.sub.3, said third conduit being connected in fluid flow communication with the downstream end portion of said first conduit. [11.] A method for atomizing a liquid stream comprising:providing the atomizer of claim 1;introducing a liquid stream to said upstream end portion of said first conduit;introducing an atomizing enhancing medium through said perforated-pipe sparger via said second conduit;contacting said liquid stream with said atomizing enhancing medium downstream from said plurality of holes of said perforated-pipe sparger thereby forming a turbulent mixture of said liquid stream and said atomizing enhancing medium;passing said turbulent mixture to said third conduit thereby converting said turbulent mixture into an annular-mist flow mixture;passing said annular-mist flow mixture to a nozzle; andwithdrawing said annular-mist flow mixture from said nozzle thereby at least partially atomizing said liquid stream to form an atomized liquid stream. A method in accordance with claim 11 wherein said annular-mist flow mixture is substantially circumferentially uniform within said nozzle. A method in accordance with claim 11 wherein said outside surface of said perforated-pipe sparger and said inside wall of said first conduit define a first cross sectional area (A.sub.xs1) having a value such that the mass flux of said liquid stream (MF.sub.1) around said perforated-pipe sparger is in the range of from about 625 lbm/(ft.sup.2 sec) to about 1050 lbm/(ft.sup.2 sec); MF.sub.1 being defined by the formula: ]EQU10 ] reinm.sub.1 =mass flow rate of said liquid stream in lbm/sec; andA.sub.xs1 =cross sectional area in ft.sup.2. A method in accordance with claim 11 wherein said plurality of holes in said perforated-pipe sparger has a total second cross sectional area (A.sub.xs2) having a value such that the mass flux of said atomizing enhancing medium (MF.sub.2) at the point of exit from said plurality of holes is in the range of from about 30 lbm/(ft.sup.2 sec) to about 50 lbm/(ft.sup.2 sec); MF.sub.2 being defined by the formula: ]EQU11 ]m.sub.2 =mass flow rate of said atomizing enhancing medium in lbm/sec; andA.sub.xs2 =cross sectional area in ft.sup.2. A method in accordance with claim 11 wherein:(D.sub.1 -D.sub.2)/2 is substantially equivalent to (D.sub.1 -L.sub.1). A method in accordance with claim 11 wherein said plurality of holes in said perforated-pipe sparger is further characterized to include a plurality of rows of holes each generally parallel to the longitudinal axis of said perforated-pipe sparger, said plurality of rows of holes including a center row, a first side row and a second side row, wherein the axes of the holes in said first side row lie in a first plane intersecting the longitudinal axis of said perforated-pipe sparger, wherein the axes of the holes in said second side row lie in a second plane intersecting the longitudinal axis of said perforated-pipe sparger, wherein the axes of the holes in said center row lie in a third plane intersecting the longitudinal axis of said perforated-pipe sparger, wherein a first angle between said first plane and said third plane is in the range of from about 40.degree. to about 50.degree., wherein a second angle between said second plane and said third plane is in the range of from about 40.degree. to about 50.degree., and wherein a third angle between said first plane and said second plane is in the range of from about 80.degree. to about 100.degree.. A method in accordance with claim 16 wherein said first side row and said second side row include in the range of from about 70% to about 90% of the total cross sectional area of said plurality of holes in said perforated-pipe sparger. A method in accordance with claim 11 wherein when said atomizing enhancing medium has a gas velocity number (N.sub.gv) and said liquid stream has a liquid velocity number (N.sub.Lv), then D.sub.3 has a value such that, as N.sub.Lv is varied, N.sub.gv exceeds:10.sup.Z ; wherein:z=(1.401-2.694 N.sub.L +0.521(N.sub.LV).sup.0.329);N.sub.gv =V.sub.sg (.rho..sub.L g.sub.c /g.sigma..sub.L).sup.1/4 ;N.sub.Lv =V.sub.sL (.rho..sub.L g.sub.c /g.sigma..sub.L).sup.1/4 ; ]EQU12 ]A.sub.xs3 =.pi. (D.sub.3).sup.2 /4N.sub.L =viscosity of said liquid stream in lbm/ft sec;.rho..sub.L =said liquid stream density in lbm/ft.sup.3 ;.rho..sub.v =said atomizing enhancing medium density lbm/ft.sup.3 ;g.sub.c =gravitational constant;g=acceleration due to gravity;.sigma..sub.L =surface tension of said liquid stream in lbf/ft;m.sub.1 =mass flow rate of said liquid stream in lbm/sec;m.sub.2 =mass flow rate of said atomizing enhancing medium in lbm/sec; andA.sub.xs3 =cross sectional area of said third conduit in ft.sup.2. A method in accordance with claim 11 wherein said atomizing enhancing medium is steam.