Fluid coking unit stripper

Abstract

An improved, fouling-resistant configuration for the stripper sheds of fluid coking units comprises an inverted, open-bottomed channel with apertures spaced along the length of the channel and spaced from the apex of the channel. Preferably, the channels are of an inverted-V configuration with a downwardly extending lip provided on each side of the channel, extending from the bottom edge of each side of the channel. The stripper sheds may be positioned parallel to one another in the stripper section of the reactor vessel or, alternatively, the sheds in different tiers in the stripper section may be disposed so that the longitudinal axes of the sheds are rotated angularly relative to the sheds in other rows.

1 . In a fluid coking unit having a reactor vessel with a stripping section including horizontally arrayed, sparged stripping sheds for stripping occluded hydrocarbons from coke product the improvement comprising the stripping sheds having a section in the form of an open-bottomed, apertured channel having its apex upwards and terminating towards the outer edges in a downwards direction. 
     
     
         2 . A fluid coking unit according to  claim 1  in which the stripping sheds have a section in the form of an open-bottomed, inverted-V configuration comprising a pair of apertured flat sides converging to an upper apex with each side ending at a bottom edge with a lip extending downwards proximate each bottom edge. 
     
     
         3 . A fluid coking unit according to  claim 2  in which the apertures in the sides are located in the upper half of each side closer to the apex. 
     
     
         4 . A fluid coking unit according to  claim 3  in which apertures are offset from the apex by 10 to 35% of the width of the side, at the center of the aperture. 
     
     
         5 . A fluid coking unit according to  claim 2  in which each stripper shed is in the form of an inverted-V section comprising a pair of flat sides extending downwards from the apex of the V where the two sides meet to bottom edges that run parallel to the apex with a flat lip extending downwards from the bottom edge of each side to increase the chamber defined by the section, each side having a row of apertures offset from the apex by 10 to 35% of the width of the side, at the center of each aperture, the total area of the apertures relative to the total surface area of each side (including apertures) being from 0.1 to 2 percent of the surface area of the sides. 
     
     
         6 . A fluid coking unit according to  claim 5  in which the total area of the apertures relative to the total surface area of each side (including apertures) is from 0.25 to 0.5 percent of the surface area of the sides. 
     
     
         7 . A fluid coking unit according to  claim 2  in which the lip extensions extend below the bottom edges of the sides to a distance of 10 to 30 percent of the width of the side (apex to bottom edge). 
     
     
         8 . A fluid coking unit according to  claim 7  in which the lip extensions extend below the bottom edges of the sides to a distance of 15 to 25 percent of the width of the side (apex to bottom edge). 
     
     
         9 . A fluid coking unit according to  claim 2  in which the stripper sheds are arranged horizontally in the stripper section in vertically spaced tiers in each of which the sheds are disposed parallel to one another in each tier and with the sheds in all tiers being parallel to one another. 
     
     
         10 . A fluid coking unit according to  claim 9  in which the stripper sheds are arranged horizontally in the stripper section in vertically spaced tiers in each of which the sheds are disposed parallel to one another in each tier and with the sheds arranged in pairs of tiers at successively vertical locations in the stripper rotated angularly from the sheds in an adjacent pair of tiers by 90°. 
     
     
         11 . A fluid coking unit comprising a reactor vessel and a heater with a stripping section at the bottom of the reactor vessel including horizontally arrayed, sparged stripping sheds disposed in vertically spaced tiers for stripping occluded hydrocarbons from coke product, each stripper shed being in the form of an inverted-V section comprising a pair of flat sides extending downwards from the apex of the V where the two sides meet to bottom edges that run parallel to the apex with a flat lip extending downwards from the bottom edge of each side to increase the chamber defined by the section, each side having a row of apertures offset from the apex by 10 to 35% of the width of the side, at the center of each aperture, the total area of the apertures relative to the total surface area of each side (including apertures) being from 0.1 to 2 percent of the surface area of the sides. 
     
     
         12 . A fluid coking unit according to  claim 11  in which the total area of the apertures relative to the total surface area of each side (including apertures) is from 0.25 to 0.5 percent of the surface area of the sides. 
     
     
         13 . A fluid coking unit according to  claim 11  in which the lip extensions extend below the bottom edges of the sides to a distance of 10 to 35 percent of the width of the side (apex to bottom edge). 
     
     
         14 . A fluid coking unit according to  claim 13  in which the lip extensions extend below the bottom edges of the sides to a distance of 15 to 25 percent of the width of the side (apex to bottom edge). 
     
     
         15 . A fluid coking unit according to  claim 11  in which the stripper sheds are arranged horizontally in the stripper section in vertically spaced tiers in each of which the sheds are disposed parallel to one another in each tier and with the sheds in all tiers being parallel to one another. 
     
     
         16 . A fluid coking unit according to  claim 11  in which the stripper sheds are arranged horizontally in the stripper section in vertically spaced tiers in each of which the sheds are disposed parallel to one another in each tier and with the sheds in alternate pairs of tiers rotated angularly from the sheds in an adjacent pair of tiers. 
     
     
         17 . A fluid coking unit according to  claim 16  in which the stripper sheds are arranged horizontally in the stripper section in vertically spaced tiers in each of which the sheds are disposed parallel to one another in each tier and with the sheds arranged in pairs of tiers at successively vertical locations in the stripper rotated angularly from the sheds in an adjacent pair of tiers by 90°. 
     
     
         18 . A fluid coking unit comprising a reactor vessel with a lower stripping section including horizontally arrayed, sparged stripping sheds for stripping occluded hydrocarbons from coke product, the stripping sheds each having a section in the form of an open-bottomed, apertured channel having its apex upwards with the apertures disposed in the upper portion of the channel, the stripper sheds being arranged horizontally in the stripper section in vertically spaced tiers in each of which the sheds are disposed parallel to one another in each tier and with the sheds in alternate pairs of tiers rotated angularly from the sheds in an adjacent tier. 
     
     
         19 . A fluid coking unit according to  claim 18  in which the stripping sheds have a section in the form of an open-bottomed, apertured channel having its apex upwards and terminating towards the outer edges in a downwards direction to define a chamber under the channel. 
     
     
         20 . A fluid coking unit according to  claim 18  in which each stripper shed is in the form of an inverted-V section comprising a pair of flat sides extending downwards from the apex of the V where the two sides meet to bottom edges that run parallel to the apex with a flat lip extending downwards proximate the bottom edge of each side to increase the chamber defined by the section.