Abstract: The specification discloses a flow distributor for distributing a flow of fluid to a bed of particles in a fluidized bed reactor. The flow distributor comprises a plurality of spaced apart discharge conduits containing exit openings for distributing the flow of fluid into the bed of particles generally across the width of the reactor from a plurality of spaced apart locations. Flow diffusers are located in the conduits upstream of the exit openings to provide multiple, spaced apart, generally parallel, flow streams within the conduits which expand and merge together as they approach the exit openings to produce a merged flow stream extending substantially across the width of each conduit prior to discharge of the flow into the reactor.

Abstract: A fluid bed reactor is provided with a loosely mounted, flexible multiperforate gas distributor plate so that in use the interaction of the flow of fluidizing gas, the plate and fluidized solids causes the plate to be flexed thereby cleaning the plate.

Abstract: For use in gas phase polymerization apparatus having an agitator in a fluidized bed polymerization reactor, the present invention provides a gas distributor which has holes, and caps covering the respective holes from above and each having an opening oriented in a substantially horizontal direction at an angle of about 90 to about 135 deg with, and outwardly of, a tangent to a circle centered about the center of the reactor whereby an increase in the gas solid ratio can be prevented in the region above the distributor to ensure efficient discharge of the polymer produced, and the polymer particles can be prevented from falling into a gas room thereunder.

Abstract: A fluidized bed-type polymerization apparatus has an upper blowing equipment installed at a definite height in the fluidized bed area. Through the equipment, a part of the circulating gas and a part, or the whole, of the fresh feed material is blown, thereby to prevent the formation of lumps of polymer in the fluidized bed portion, owing to improved intermixing at the upper portion of the fluidized bed, as well as efficient heat-removal at that portion.

Abstract: Distributor device comprises at least one lower and/or one upper stationary distributor device for distribution of fuel in the form of gas and particles in a fluidized bed and is arranged above fuel feed nozzles in the bed, or at or above the upper limit of the bed. The task of the distributor device is to spread fuel, rising upwards in the bed, more evenly over a large area in the bed and to create turbulence above the bed. This is achieved by designing the distributor device with a mid-portion and upwardly-inclined wing-like members or the cone to bring about even distribution of fuel by forcing the fuel to follow an outwardly-directed horizontal or obliquely upwardly-rising flow of fuel.

Abstract: A nozzle assembly which comprises nozzle duct having inlet and discharge ends is provided with a tubular support. The support has a first end in fluid communication with the nozzle duct adjacent the discharge end thereof. The second end of the support extends to a location where it is accessible, to enable a source of cleaning fluid to be coupled thereto, and is normally capped.

Abstract: A rotating fluidized bed reactor in which inert solid particles are held in place by centrifugal forces. The reactor includes a rotating porous bed vessel drum within a plenum vessel and the drum rotates to hold the solid particles at the side thereof. Gas is introduced through the walls of the drum and can be drawn off at the top. An electromagnetic radiation source can be included within the drum for promoting photochemical reactions. The solid particles can be inert particles that are loaded with reactant which reacts with the gas stream and/or from the electromagnetic radiation. In other embodiments of the invention, the particles do not contain reactant and reactant is provided within the gas stream only. Such a rotating bed reactor is suitable for use with both batch and continuous flow through processes.

Abstract: A gas distribution system employing an array of parallel gas inlet pipes and a pair of transverse gas inlet pipes located below the first group of pipes to fluidize a particulate bed in a reaction vessel and to remove non-fluidizable particles that may be introduced into or form in the bed.

Abstract: Disclosed is a fluid catalytic cracking system in which the catalytic cracking reaction takes place in a dilute phase, and the reaction product contains a reduced volume of off gas having a low concentration of SO.sub.x and NO.sub.x. The use of off gas, which is produced during a regeneration step, to strip entrained vapor from spent catalytic cracking catalyst acts to reduce SO.sub.x and NO.sub.x byproducts, and eliminates the need to separately recover and treat the off gas stream from the regenerator portion of the system. The entire process, including the reaction step, the stripping step and the regeneration step, can be performed in a single non-partitioned vessel.

Abstract: A method and a device for preheating a particulate fluidized bed which is supplied with air for fluidization of bed material and for combustion of main fuel through gas paths that include fluidization members for injection and distribution of the air over the fluidized bed. The bed material is preheated to the ignition temperature for the main fuel used in the fluidized bed by members arranged in the gas paths for combustion of starting fuel. These members are designed and arranged so that the air is supplied to the fluidized bed along the same path through gas paths and fluidization members upon preheating with starting fuel as upon combustion of main fuel in the fluidized bed. The members for combustion of starting fuel are arranged in the fluidization members and comprise fuel injectors, fuel pipes, ignition members and control members.

Abstract: A distillation column reactor is provided having special trays arranged within the column to provide better mixing and thus achieve better mass and energy transfer between the liquid, vapor and catalyst. The trays comprise a slotted support plate for the catalyst with openings to allow vapor passage through the catalyst from the tray below. A draft chimney or riser is provided directly above the slotted openings to increase the vapor velocity and carry the liquid and catalyst upward on the tray. A hood is included at the upper end of the chimney to direct the liquid-vapor-catalyst flow back down onto the tray. The liquid from the tray above is distributed onto the tray about the chimney by distributors which preferably extend below the static catalyst level on the tray.

Abstract: In a fluidized bed reactor particles are internally circulated, moving down the walls forming the reactor chamber. A particle chamber having a particle gathering top wall with a horizontal projection area A is disposed in the downward flow of particles. Openings (e.g. holes or slots) with a controlling dimension of about 30 mm or less are provided in the top wall, the openings having total open area B less than half the area A. Heat transfer surfaces may be disposed in the particle chamber.

Abstract: A special sealing arrangement provides a chamber between hot metallic internals attached to cold wall pressure vessel shells to preserve the integrity of the lining and to minimize thermal stresses imposed on the shell and the internals. The sealing element of this invention is a mesh blanket composite having opposite ends secured by different brackets to the internal structure and the cold wall pressure vessel shell. The membrane composite allows gases to escape from a heat transfer chamber between the internal structure and the pressure vessel shell while blocking the passage of catalyst into the chamber. This catalyst seal device is particularly useful in FCC units where fine catalyst particles can migrate into expansion chambers provided between an internal cone and the regenerator shell.

Abstract: A coating-fluidizing gas supply system for a flat-bottom fluidized bed coater that maintains a high degree of uniform fluidization of levitated particles for a long enough time period to coat medical-device components. The coating-fluidizing gas supply system prevents premature pyrolysis of the coating component of the gas from plugging gas-distributor holes of a flat plate at the bottom of a flat-bottom fluidized bed coater, by directing multiple gas streams uniformly against the entire undersurface of the flat gas-distributor plate, creating an overall cooling-effect on the gas-distributor plate which prevents clogging.

Abstract: In a vertical cylindrical casing (1) of the apparatus along the axis thereof a gas-supplying pipe (8) is disposed, the end face (11) of which is disposed above a gas-distributing grating (3) at the level of the height of a fluidized bed formed thereon and in which a tube (12) is arranged with a swirler (13) inserted thereinto, said tube forming an annular gap (14) with the pipe (8). On the gas-supplying pipe (8) and on the gas-distributing grating (3) truncated cones (15, 16) are arranged coaxially, the upper end face (17) of the external cone (16) being disposed below the end face (11) of the gas-supplying pipe (8). In the upper part of the casing (1) in front of the inlet to an axial gas-discharging pipe (7) a baffle cone (19) is mounted.

Abstract: A direct resistance heating electrical furnace of the type in which a bed of electrically conductive elements are located between two spaced electrodes in the furnace, and a method of controlling the operation of same, are provided. The furnace is of the type having a generally tubular heating chamber with a pair of spaced electrodes associated therewith and conveniently located one at each end of the tubular heating chamber. The furnace has feed or discharge control means and the rate of feed or discharge is controlled according to the electrical resistance or current flow between the electrodes. No temperature measurement is required to control the furnace operation.

Abstract: A fluidized coating apparatus wherein a rotatable perforated disk 2 is provided at the lower portion of a processing cylinder 1 and perforated disk opening portions 3 are provided in the vicinity of the outer peripheral edge of this perforated disk 2. The ratio of the total opening area of the perforated disk opening portions 3 to an area of an annular slit 8 formed between the perforated disk 2 and the inner wall of the processing cylinder 1 is within the range from 0.2 to 0.6. Each of the perforated disk opening portions 3 is provided with a cover and side walls so that gas is blown out outwardly in the radial direction or obliquely backward with respect to a rotating direction within 30.degree. to the radial direction of the perforated disk.

Abstract: An improved sulfider is provided for receiving high temperature catalysts from the hydrocarbon cracking operation and subjecting the catalyst to a sulfur-containing gas. The sulfider unit includes a plurality of gas injector tubes each individually removable from the sulfider while gas is continually injected into the sulfider treatment chamber through other of the injection tubes. Each injector tube may extend through a lowermost end of the sulfider, and has a central tube axis arranged substantially vertically when the tube is mounted to the sulfider housing. Fluid output ports are provided in sidewalls of an upper portion of the tube, and the tubes may be continually operated for extended periods of time without significant plugging problems. A service valve and packing unit associated with each injector tube enable partial removal of the tube from the treatment chamber without leakage of hydrogen sulfide gas, followed by closing of the valve and complete removal of the tube and packing unit.

Abstract: A process and apparatus for achieving turbulent or fast fluidized bed regeneration of spent FCC catalyst in a bubbling bed regenerator having a stripper mounted over the regenerator and a stripped catalyst standpipe within the regenerator. A coke combustor vessel, which may be partially or totally open to the dilute phase above the bubbling bed, is added to the existing regenerator vessel Spent catalyst is discharged into the coke combustor, regenerated in a turbulent or fast fluidized bed, then discharged into the dilute phase region above the bubbling bed, either via a deflector or by simply overflowing the combustor. Regeneration of catalyst is completed in the bubbling dense bed, and/or an annular fast fluidized bed surrounding the coke combustor. Catalyst may be recycled from the dense bed to the coke combustor either by a flow line, or by adjusting relative heights of bubbling to fast fluidized bed.

Abstract: Disclosed herein is a gas dispersing device to be employed in a fluidized bed preliminary reducing furnace. The gas dispersing device is constructed of a plurality of rotatable round bars arranged in multiple stages so as to form a grate. The gas dispersing device includes a rotating mechanism for rotating each bar.According to the present invention, deformation of the bars due to a temperature change thereof can be avoided to thereby extend a life of the dispersing device. Furthermore, blinding of the dispersing device can be prevented to thereby effectuate a stable operation of a fluidized bed. Accordingly, productivity in the fluidized bed reducing furnace is improved, and labor saving is realized.

Abstract: A fluidized catalytic cracking process and apparatus operates with a single or multi- stage refluxed catalyst stripper. Recycle, or reflux, of stripped catalyst to the stripping zone improves stripping. Preferably, a two stage hot stripper is used. Addition of regenerated catalyst to spent catalyst from the reactor heats spent catalyst in a first stripping stage, which preferably uses stripping steam. Catalyst from the first stripping stage passes up through a second stage stripping zone with a heat removal means, e.g., a stab-in tube bundle. Steam or flue gas fluidizes catalyst, improves heat transfer and strips the catalyst. Some catalyst from the second stage stripper is preferably recycled to the inlet to the first stripping stage. Additional hot regenerated catalyst may be added downstream of the first catalyst stage to heat the second stripping stage, added to catalyst removed from the primary stripping zone which is sent to the regeneration zone.

Abstract: A reaction-distillation apparatus is provided comprising at least one reaction-distillation zone including at least one bed of solid elements disposed on a fluid-permeable perforated support having perforations small enough to retain the elements wherein the bed of solid elements includes loose solid catalytic particles and at least one receptacle, containing at least one distillation packing body, the external jacket of which is permeable to fluids and the impermeable to the solid catalytic particles and packing body. The apparatus can be used for carrying out chemical reaction and concomitant fractionation of the reaction mixture, for example, to synthesize ethers from olefins and alcohols.

Abstract: A fluidized bed reactor uses fluid conduits for supplying fluids (such as liquid, gaseous, or fine solid material in suspension fuels), into a reactor chamber. The fluid conduits extend horizontally from, and substantially perpendicularly to, a side wall into the reactor chamber. The fluid conduits are disposed at a level (e.g. about 100-1000 mm) above the fluidizing gas nozzles in the bottom of the reactor chamber. An upright partition, preferably of refractory material, covers the fluid conduits.

Abstract: A fluidized bed apparatus (1) having a fluidization grid (2) below which is positioned a tuyere (5) for guiding fluidization gas to the fluidization grid (2). The tuyere (5) comprises a widening pipe the wider end (6) of which is positioned towards the fluidization grid (2) and has an area which is substantially the same as the cross-sectional area of the fluidized bed apparatus (1) and is 2 to 30 times that of the area of the narrower end (7) of the widening pipe. The process for feeding fluidization gas to a fluidized bed using such apparatus enables a good gas distribution across the bed to be achieved with a modest additional pressure drop. The invention is particularly useful for apparatus e.g. greater than 3 m in diameter.

Abstract: A riser reactor which includes a wall extending downward to an enlarged housing at the bottom of the riser reactor, where the housing has (a) an inlet for introducing catalyst particles into the housing and includes a first fluidization device, where the length of the inlet is from two to three times the diameter of the inlet, and (b) a second fluidization device below the first fluidization device, and (c) where the housing has above the inlet a centrally arranged diamond-shaped directing structure secured to the wall, where the directing structure has a lower and upper portion and where the directing structure and the wall define a passage, where the lower portion of the directing structure and the wall defines an upwardly converging portion in the passage and where the upper portion of the directing structure and the wall define an upwardly diverging portion in the passage.

Abstract: An endothermic gas generator having separate sources of oxygen and hydrocarbon gas at pressures above the pressure of the endothermic gas to be produced, the sources of oxygen and hydrocarbon gas being interconnected through separate pressure reducing valves and to a gas tight reaction chamber, the reaction chamber containing catalyst bodies and being heated to a temperature sufficient to support a reaction between carbon atoms and oxygen atoms to produce an endothermic gas, the reaction chamber having a outlet port for an endothermic gas resulting from the reaction of the oxygen and the hydrocarbon gases at a pressure approximately that of the mixture of gases entering the reaction chamber.

Abstract: A laboratory instrument provides a small model reactor which better simulates a back mixed reactor containing a catalyst. The reactor is especially valuable for simulating commercial scale hydrotreating of petroleum resid, coal, and other non-distillable hydrocarbons to obtain some distillable products. An important feature is a magnetically driven pump completely enclosed within the reactor shell of the simulator. All embodiments provide a high temperature and pressure, low liquid to catalyst volume, model reactor where an entire process is carried out within the simulator shell under substantially the conditions prevailing in the full scale reactor.

Abstract: The grid plate is disposed between the fluidized bed reactor chamber and an underlying wind box and includes a plurality of nozzles for feeding fluidizing gas from the wind box into the reaction chamber. The nozzles are configured to afford different pressure drops across the grid such that with increasing pressure, additional nozzles are actuated in response to increasing pressure differences across the plate whereby fluidized bed start-up and steady state operating conditions may be facilitated.

Abstract: In a method of operating a fluidized bed, gas under pressure is distributed into the bed through a gas permeable member extending transverse to the bed and a gas permeable wall of a discharge conduit wherein the relative permeability of the gas permeable member and the conduit is selected so as to obtain a desired distribution of gas entering the bed and a desired effect on the fluidization pattern in the bed.

Abstract: Catalytic regenerators, nozzle designs and processes suitable for introducing regeneration air into a catalytic cracking unit which substantially reduce erosion induced nozzle failures include a plurality of nozzle elements having a roughness defined upon the outside surface of said nozzle elements so as to reduce erosion due to the impact of fluidized catalyst particles within the catalytic regenerator.

Abstract: A device for the introduction of a liquid in a medium containing granulate material for the fluidization of this material, intended more particularly for equipping reactors such as those used for the biological treatment of aqueous effluents, characterized in that it is made of a part, bearing on the bottom of the reactor, the upper portion of said part cooperating with the liquid injection tube so as to create a flow with a very small turbulence of the liquid at the tube outlet and the shape of which being such that it provides, at all points of the apparatus, without dead zones, the setting in movement of the material to be fluidized.

Abstract: Disclosed are a process and apparatus for effecting chemical and/or physical reactions by means of solid-gas contact. The apparatus has a shaftlike reaction chamber widening in upward direction and divided into compartments by means of horizontal grids. The process is performed by introducing a particulate solid of about 0.5 to 5 millimeters particle size into the reaction chamber and passing a gas stream in upward direction through that chamber at an output sufficient to keep the particles in floating condition. A floating bed of solid particles will be formed in the reactor then and excellent solid-gas contact suitable for effecting chemical and physical reactions is provided hereby. A special embodiment relates to the removal of nitrogen oxides from flue gases with the aid of a particulate catalyst.

Abstract: Disclosed are devices for introducing and uniformly distributing spent catalyst into a regenerator bed of a fluid catalytic cracking unit. Also disclosed are devices for collecting and discharging regenerated catalyst from the regenerator bed. The devices provide more uniform contacting of the spent catalyst particles with regeneration gas and consequently more efficient and complete regeneration.

Abstract: In a treatment chamber (12) having a gas inlet (16) and gas outlet (18) to produce a general flow of gas (E) directed from the bottom to the top a hollow lance (40) extends transversely of the general flow of gas (E) between two pairs of guide vanes (42,44). The outline of the lance (40) is symmetrical with respect to a vertical center plane (A), and it includes a conveyor channel (60) which extends in longitudinal direction of the lance and to which discharge nozzles (80) for material are connected. A pair of semishells (52) are arranged above the guide vanes (42,44) and, together with the guide vanes (42,44), they form a straight trough (53) which is at least approximately symmetrical with respect to the center plane (A). A pressure gradient can be produced between the gas inlet (16) and the gas outlet (18) at which gradient a rectilinear fluidized bed (F) is formed within the trough (53).

Abstract: A method and apparatus are disclosed for producing polyolefins by a fluidized gas phase polymerization process utilizing two stacked, substantially vertically aligned, reactors and a substantially vertical product transfer line for transfer of intermediate polyolefin polymer product from the polymerization zone of the upper reactor to the polymerization zone of the lower reactor. This abstract shall not be construed to define or limit in any way the scope of the invention, which is measured solely by the appended claims.

Abstract: An apparatus for removing sulfur values from a hot fuel gas stream in a fdized bed contactor containing particulate sorbent material by employing a riser tube regeneration arrangement. Sulfur-laden sorbent is continuously removed from the fluidized bed through a stand pipe to the riser tube and is rapidly regenerated in the riser tube during transport of the sorbent therethrough by employing an oxygen-containing sorbent regenerating gas stream. The riser tube extends from a location below the fluidized bed to an elevation above the fluidized bed where a gas-solid separating mechanism is utilized to separate the regenerated particulate sorbent from the regeneration gases and reaction gases so that the regenerated sorbent can be returned to the fluidized bed for reuse.

Abstract: A mechanism for the prevention of distributor plate pluggage by dust-laden gases in multistage fluidized-beds is disclosed. Slanted tubes are used to control the flow of gases into a fluidized bed, where the angle between the slanted tube and the distributor plate is less than the angle of repose of the bed solids.

Abstract: A fluidized bed combustion method for burning wastes using a fluidized bed furnace is not affected by a fluctuation in the quantity and quality of wastes fed into the furnace, if any, thereby preventing CO gas, etc. from discharging out of the furnace. The furnace has a number of air-diffusing tubes for feeding primary air to the fluidized bed in parallel with each other at the bottom of the fluidized bed, and a free space part formed above the fluidized bed for burning unburnt matter with a secondary air. Each air-diffusing tube has a number of nozzles provided along the axis of the tube and a primary air control device including an open-close damper for controlling the quantity of air to be fed through the tube. The primary air is fed into the fluidized bed through the air-diffusing tubes one after another according to a predetermined open-close pattern by the primary air control device so that the ratio of the air quantity Uo to the minimum fluidizing air quantity Umf (Uo/Umf) is in the range of 1.

Abstract: An ebullated bed reactor into which is introduced a mixture of a gaseous substance, such as hydrogen-rich gases, and a liquid substance, such as vacuum reduced crude or resid, beneath a grid plate disposed in the reactor. Bubble cap risers extend through the grid plate uniformly transmit this gaseous and liquid substance mixture to a catalyst bed disposed above the grid plate. The grid plate is connected to an inner wall of the reactor so that a leakage path might be formed between the grid plate and the support ring of the reactor wall. A skirt is disposed beneath the grid plate to maintain a portion of the gaseous substance in a specific area beneath the grid plate to allow proper distribution of the gaseous flow through the bubble cap riser assemblies. Thus, the portion of the gaseous substance which is maintained beneath the grid plate is prevented from escaping into the reactor via any space which may appear in the grid plate and outside the area which is surrounded by the skirt.

Abstract: Fluidized bed reactor method and apparatus for removal of coarse material from the reactor. The apparatus comprises a discharge device including a substantially vertical pipe portion connected at one end with an outlet opening in the reactor grid, and at another end to an aeration chamber containing a discharge opening located below the level of the grid outlet opening; and a device for supplying pressurized air in short blasts of 30 to 100 milliseconds, preferably at pressures of from 2.5 to 7.0 bar, into the aeration chamber in the direction of the discharge opening to remove the coarse material from the reactor. Low pressure fluidizing air may be supplied to the vertical pipe portion as well as the aeration chamber to return small particles in the discharge device to the fluidization zone of the reactor.

Abstract: The present invention relates to a fluidized bed apparatus comprising a fluidization grid arranged in the lower part of this apparatus, this grid being provided at its center with a circular aperture communicating with a discharge chamber and occurring in the form of a surface of revolution consisting of the joined lateral surfaces of at least two coaxial truncated cones of revolution, virtual vertices of which are oriented downwards.

Abstract: Modern processes and arrangements for FCC processes can be obtained using a stacked FCC reactor-regenerator arrangement. These processes and arrangements use a stacked FCC unit having a bottom regeneration vessel, a superadjacent reactor vessel, and a stripping vessel laterally offset from and in open communication with the reactor vessel to make a two-stage regenerator having a lower first stage regeneration, an upper second stage of regeneration, and a catalyst cooler for removing feed from the catalyst. The process and arrangement makes complete use of the three existing vessels in the stacked reactor-regenerator arrangement by changing the function of the upper reactor vessel and the stripping vessel and adding a reactor vessel to the side of the stacked FCC arrangement. Therefore, apart from the addition of the new reactor only relatively minor modifications are necessary to more fully utilize stacked FCC reactor-regenerator arrangements.

Abstract: The present invention contemplates an improved grid for fluid bed reactors which minimizes catalyst coking in fluidized catalytic cracking operations by shedding catalyst dispersed through the grid from feed risers located therebelow. Indeed, the grid has a central portion containing a plurality of orifices therein and a downwardly extending annular ring portion for shedding catalyst outwardly and downwardly for collection and removal from the reactor vessel.In the preferred embodiment of the present invention, the grid consists of a convex upper grid and a concave lower plate joined together and defining a disengaging zone therebetween. At least one riser opens into the disengaging zone for introducing the material to be fed into and separated in the reactor. The upper grid includes a solid annular ring which extends outwardly and downwardly from the point at which the upper grid and the lower plate are joined.

Abstract: An apparatus and process for transferring and regulating the recycle of particulate solids separated from a gas-particulate solids suspension in which an auxiliary vessel and slanted pipe are provided to transfer and regulate particulate solids flow.

Abstract: A method and apparatus are disclosed for producing polyolefins by a fluidized gas phase polymerization process utilizing two stacked, substantially vertically aligned, reactors and a substantially vertical product transfer line for transfer of intermediate polyolefin polymer product from the polymerization zone of the upper reactor to the polymerization zone of the lower reactor. This abstract shall not be construed to define or limit in any way the scope of the invention, which is measured solely by the appended claims.

Abstract: The invention relates to a method and a nozzle bottom for controlling the mixing of gaseous flows in fluidized bed reactors and circulating fluidized bed reactors. In the method, part of the combustion air is introduced into a reactor chamber through fluidizing nozzles (11) positioned in a nozzle bottom (4). In order to improve the controllability of a combustion process, the remaining part of the combustion air is according to the invention introduced through essentially vertically directed jet nozzles (12) positioned in the nozzles bottom (4), and the vertical penetration of the air jets applied through the jet nozzles (12) is maintained at a value essentially higher than the vertical penetration of the air jets applied through the fluidizing nozzles (11).

Abstract: The grid plate is disposed between the fluidized bed reactor chamber and an underlying wind box and includes a plurality of nozzles for feeding fluidizing gas from the wind box into the reaction chamber. The nozzles are configured to afford different pressure drops across the grid such that with increasing pressure, additional nozzles are actuated in response to increasing pressure differences across the plate whereby fluidized bed start-up and steady state operating conditions may be facilitated.

Abstract: This invention provides an improved method for stripping hydrocarbons from spent catalyst which has been used in effecting hydrocarbon conversion reactions prior to the regeneration of this catalyst by combustion of carbon deposits upon the catalyst. The invention is described in terms of its use in FCC processes, since such processes are the most common application of the invention. In order to better distribute stripping gas, which is normally steam, so that the gas contacts and passes through substantially all of the catalyst, distribution ports are added to the skirts of the stripper baffles which direct catalyst flow in a generally side-to-side manner as it moves downward through a stripping vessel. The ports are sized to vary penetration of the stripping gas into the stream catalyst that moves past the grids. Use of these ports increases the amount of hydrocarbons removed from the spent catalyst and/or decreases stripping gas requirements.

Abstract: The fluidizing grid of the invention is essentially constituted by pipes (18) forming the diverging walls of the openings (17) through which the fluidizing air is blown. These pipes have a cooling liquid (water) flowing therealong, which water then flows through the heat exchange tubes of the boiler.

Abstract: A fluid catalytic cracking (FCC) process and apparatus which employs relatively more elutriatable catalyst particles comprising intermediate pore zeolite, particularly ZSM-5, and relatively less elutriatable catalyst particles comprising large pore zeolite, preferably zeolite Y. The process and apparatus employ a first stripping vessel which also separates a more elutriatable first portion of catalyst from a less elutriatable second portion of catalyst. The more elutriatable first portion passes to a second stripping vessel, and subsequently recycles to a fluid catalytic cracking reactor riser. The second portion of less elutriatable catalyst passes from the first stripping vessel to a fluid catalytic cracking regenerator vessel and, after being regenerated, recycles to the reactor riser. The more elutriatable first portion contains a higher ratio of intermediate pore catalyst particles to large pore catalyst particles than does the second portion.