Phillips Petroleum Company

William C Rahlwes

Kelly G Knopp

Ralph G Carrasco, Jr

In a steam generator for recovering heat in a hot fluidized bed of solid particles, wherein coils of the steam generator make a 180.degree. U-bend, the U-bend portion of the coils are protected from overheating by installing an open top insulating box around the U-bend portion of the coil. In use solid particles from the circulating fluidized bed accumulate in the insulating box thus providing a non-moving layer of solid particles surrounding the U-bend which thermally insulates the U-bend portion of the coil from the higher temperature encountered in the moving fluidized bed.

Method of protecting heat exchange coils in a fluid catalytic cracking

In a steam generator for recovering heat in a hot fluidized bed of solid particles, wherein generally horizontally oriented coils of the steam generator make a 180.degree. U-bend, the U-bend portion of the coils are protected from overheating by installing an open top insulating box around the U-bend portion of the coil. In use solid particles from the circulating fluidized bed accumulate in the insulating box thus providing a non-moving layer of solid particles surrounding the U-bend which thermally insulates the U-bend portion of the coil from the higher temperature encountered in the moving fluidized bed.

Protected coils for a steam generator

Catalytic regenerators, nozzle designs and processes suitable for introducing regeneration air into a catalytic cracking unit which substantially reduce erosion induced nozzle failures include at least one nozzle which has at least one planar surface generally parallel to the nozzle's longitudinal axis.

Catalyst regeneration

Catalytic regenerators, nozzle designs and processes suitable for introducing regeneration air into a catalytic cracking unit which substantially reduce erosion induced nozzle failures, include at least one nozzle which has at least one planer surface generally parallel to the nozzle's longitudinal axis. In another embodiment, at least one nozzle has a plurality of planer surfaces generally parallel to the nozzle's longitudinal axis.

Apparatus for use in a fluid separation vessel to improve the separation of liquids of different densities which includes a tubular conduit extending upwardly a distance from a liquid outlet in the bottom of the vessel, a vertical center plate disposed across the open upper end of the tubular conduit, a pair of mutually parallel vertical side walls on opposite sides of the tubular conduit mounted perpendicular to the center plate, and a horizontal baffle plate mounted on the upper edges of the center plate and the vertical side walls.

Vortex breaker for use in a liquid-liquid separator or the like

A hexanes stream, including normal hexane, isohexanes, methylcyclopentane and cyclohexane is isomerized by first fractionating the hexanes stream in a first fractionation step to produce a normal hexaneisohexanes rich overhead stream and a methylcyclopentane-cyclohexane rich bottoms stream, the bottom stream of the first fractionation step is isomerized to maximize the conversion of methylcyclopentane to cyclohexane, the overhead stream from the first fractionation step is fractionated in a second fractionation step to produce an isohexane rich overhead stream and a normal hexane rich bottoms stream, the effluent from the isomerization step is fractionated in at least one stage of a third fractionation step to produce a cyclohexane rich bottoms fraction and a methylcyclopentane-isohexane rich overhead stream and at least a part of the overhead stream from the third fractionation step is recycled to at least one of the isomerization steps and the first fractionation step. In one mode of operation, the overhead from the first stage of the third fractionation step is separated into an overhead stream rich in isohexanes which is combined with the overhead from the first fractionation step and passed to the second fractionation step and a bottoms stream rich is methylcyclopentane is thus recycled to the isomerization step or the first fractionation step. In a second mode of operation, the overhead from the first stage of the third fractionation step is recycled directly to the isomerization step and/or the first fractionation step.

Isomerization process

A hexanes stream, conventionally produced in petroleum refining, comprising normal hexane, isohexanes, methylcyclopentane, and cyclohexane is isomerized to produce primarily cyclohexane and to recover normal hexane by first fractionating the hexanes stream in a first fractionation step in a manner and under conditions to produce a normal hexane-isohexane rich overhead stream and a methylcyclopentane-cyclohexane rich bottoms stream, the bottoms stream is isomerized in the presence of an isomerization catalyst and under conditions sufficient to maximize the conversion of methylcyclopentane to cyclohexane, the overhead from the first fractionation step and the effluent from the isomerization step is then fractionated in at least one stage of a second fractionation step in a manner and under conditions to produce separate streams, comprising isohexanes, normal hexane, cyclohexane, and unreacted methylcyclopentane and the methylcyclopentane is recycled to the isomerization step and/or the first fractionation step. Since an original hexane stream usually contains benzene, it is preferred that the original hexane stream be hydrogenated to convert the benzene to cyclohexane prior to passing the feed to the first fractionation step.

Growing community of inventors

West Columbia, TX, United States of America

William C Rahlwes