Slotted Plate Scallop

Abstract

To provide an improved scallop design for a radial direction reactor.SOLUTION: A device in a radial direction reactor 200 comprises: a perpendicularly long and narrow conduit 225 extending around an outer wall of the radial direction reactor, in which the conduit is equipped with an inner face 230, an outer face 235 and a pair of opposing side faces 237, where the inner face has a plurality of slots, and the pair of opposing side faces have a plurality of opening part 239, and a riser 215 at one end of the perpendicularly long and narrow conduit; a perpendicularly oriented cylinder center pipe 260 in the radial direction reactor; a catalyst bed 240 defined by the center pipe and the inner face; and at least one stiffener extending from the inner face to the outer face.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] (Priority statement) This application claims the benefit of U.S. Provisional Patent Application No. 62 / 967,833, filed January 30, 2020, the entire contents of which are incorporated herein by reference. [Background technology]

[0002] The present invention relates to the field of fluid-particle contacting and to devices for contacting fluids and particles. The present invention further relates to a fluid conduit forming the outer retaining wall of an annular particulate bed used in a radial flow system attached to a cylindrical vessel. In such systems, fluid is typically directed radially inward or outward into or out of the particulate bed through openings in the inner surface of a plurality of outer, vertically disposed conduit members or through openings in a cylindrical screen basket member having a diameter smaller than the inner wall of the vessel. The fluid passes through openings in a vertically disposed central pipe forming the inner retaining wall of the annular particulate bed. More specifically, the present invention relates to a fluid conduit having at least one tapered side surface relative to at least one reactor wall.

[0003] A wide variety of processes use radial flow reactors to provide contact between fluids and solids, usually containing catalytic materials with which the fluids react to form products. These processes span a variety of processes including hydrocarbon conversion, gas processing, and adsorption for separations.

[0004] Radial flow reactors are constructed so that the reactor has an annular configuration and an annular dispersion and collection device is present. The dispersion and collection device incorporates some type of screened surface. The screened surface holds the catalyst bed in place and aids in distributing pressure across the reactor surface to promote radial flow through the reactor bed. The screen can be either mesh, wire, or other material, profiled wire, or perforated plate. In the case of a moving bed, the screen or mesh provides a barrier to prevent loss of solid catalyst particles while allowing fluid to flow through the bed. Solid catalyst particles are added at the top, flow through the device, and are removed at the bottom, passing through a screened enclosure that allows fluid flow over the catalyst. The screen is preferably constructed of a non-reactive material.

[0005] The screens or meshes used to retain catalyst particles within the bed are sized to have openings small enough to prevent particles from passing through. The vessel is typically a reactor containing a bed of particulate material, such as catalyst, absorbent, resin, or activated carbon. The fluid passing radially through the particle bed is usually a gas, but it can also be a liquid or a liquid / gas mixture. In prior art systems, the outer wall support for the annular particle bed is often a ring of individual scalloped members with convex inner and outer surfaces that conform to the vessel wall. The scalloped members can be formed from metal plates containing perforations whose diameter is smaller than the size of the particulate material. They can also be formed with their convex inner surfaces containing screen elements with multiple closely spaced wires welded to support rods. Such scallops are often sized so that they can be installed or replaced as needed by lifting them through an opening in the top of the vessel. Another type of prior art system includes a cylindrical screen basket member spaced inward from the outer wall of the vessel. Such cylindrical screen basket members cooperate with an inner screen pipe member to ensure that the particle bed positioned between such inner and outer members has a uniform thickness. However, the system, like the scalloped screen, This is very expensive because a large diameter screen cannot be installed or removed through the small top opening in the scallop ring. In other embodiments, the same function can be achieved in place of the individual scallops by a screen attached to cover the same area as the ring of individual scallops.

[0006] Examples of prior art systems having scalloped members around the inner surface of the outer vessel include U.S. Pat. No. 3,167,399 to Hansen, Jr. and U.S. Pat. No. 5,209,908 to Koves et al. U.S. Pat. No. 4,374,094 to Farnham shows vertical screen segments surrounding an annular catalyst bed spaced from the sidewall of the vessel. U.S. Pat. No. 4,540,547 to Schuurman shows a moving-bed reactor in which a ring of screen segments surrounds a centrally located catalyst bed and separates the catalyst from an outer annular chamber that receives the effluent after it passes through the screen surface. European Patent No. 0483975 to Nagaoka shows a device for retaining particulate catalyst in a radial-flow reactor that includes a ring of vertically arranged vessels having abutting sidewalls and screened inner walls, the vessels packed with catalyst and positioned between an outer annular fluid chamber and an inner cylindrical fluid chamber.

[0007] Therefore, there is a need for improved scallops for radial flow reactors. [Brief explanation of the drawings]

[0008] [Figure 1] 1 illustrates an embodiment of a vertically elongated conduit of the present invention. [Figure 2] 1 illustrates another embodiment of a vertically elongated conduit of the present invention. [Figure 3] 1 illustrates another embodiment of a vertically elongated conduit of the present invention. [Figure 4] 1 shows an embodiment of a device having a tapered front wall. [Figure 5A] 1 illustrates various embodiments of a segmented conduit. [Figure 5B] 1 illustrates various embodiments of a segmented conduit. [Figure 5C] 1 illustrates various embodiments of a segmented conduit. [Figure 5D] 1 illustrates various embodiments of a segmented conduit. DETAILED DESCRIPTION OF THE INVENTION

[0009] A problem exists in radial flow reactors, where catalyst flows through an annular region defined by an inner screened partition and an outer screened partition, which define a catalyst bed, or particle retention volume, for holding particulate solids. A fluid, usually a gas, flows over the partitions and catalyst bed, reacts with the catalyst, and produces a product fluid, usually a gas. The reactor retains the catalyst with screens through which the gas flows. The dimensions of these screens are typically established to minimize the pressure drop required to provide uniform radial and axial gas distribution, which requires a significant volume within the reactor. Existing prior art scallops and outer baskets for these processes all have a constant cross-sectional area along the length of the scallop / basket.

[0010] U.S. Patent No. 10,384,181 describes one solution: the device is oriented so that the solids flow through the device in a downward, or gravity direction, with a cross flow of gas, and therefore the use of the terms downward and upward refers to orientation relative to the direction of gravity.

[0011] The catalyst bed depth and volume can be varied, providing advantages in the operation of radial flow reactors. This is useful in the chemical industry for maximizing reactor vessel volume utilization, and using the design of the '181 patent, it is possible to increase the total catalyst content in the reactor by more than 20%. A further advantage of the design of the '181 patent is that the catalyst can be utilized more efficiently. As the catalyst passes through the reaction space, Because coke buildup can cause deactivation in the lower regions of the reactor, longer residence times in the lower reactor regions are favorable for process chemistries involving catalyst deactivation. Hydraulic balancing is used to achieve significant increases in bed depth within the constraints of the cross-flow internal screen pinning design and pressure drop across the reactor. The path length seen at the base of the vessel can even be increased by more than 33% in some cases.

[0012] The sizing (depth) of the reforming scallops is typically driven by the riser inlet components to achieve an acceptable pressure drop for feed distribution and minimize the overall system pressure drop. This allows for a large overall equipment volume. Scallops and equivalent functional reactor internals are configured with a varying cross-sectional area along the length of the scallop / basket (larger cross-sectional area near the inlet / outlet nozzles and smaller cross-sectional area at the opposite end). In some cases, this configuration can be reversed.

[0013] In a radial flow reactor, the reactor has an inner surface and an outer surface, and the catalyst is disposed between the inner and outer surfaces, forming a cylindrical structure. Depending on the desired flow characteristics, the inner surface can be the inlet partition and the outer surface can be the outlet partition. Alternatively, the outer surface can be the inlet partition and the inner surface can be the outlet partition. Characteristics that determine the selection include, but are not limited to, fluid flow rate, such as expansion or contraction of the fluid due to an increase or decrease in the number of moles of chemical in the fluid, and temperature changes in the fluid.

[0014] The '181 patent's scallop design involves contouring / tapering the rear enclosure section from the top to the bottom of the scallop to accommodate risers for pressure drop minimization and distribution in the upper and downstream sections of the scallop, gradually decreasing in cross section to accommodate a volume reduction approaching a nominal 50% reduction in the original design size. Contouring / tapering the rear enclosure section also allows for maintaining a flat-profile wire front that establishes uniform catalyst bed depth, creating a new, replaceable design feasible for rebound service. Because 95+% of the feed enters the riser within the scallop and is contained within the enclosed scallop, the pocket behind the contoured / tapered scallop is unaffected, and the reactor can remain cylindrical without modification or design modifications. The gradually decreasing cross section from top to bottom also advantageously reduces velocity head conversion (approaching constant velocity or deceleration) and allows for reasonable distribution with reduced pressure drop built into the system.

[0015] Prior art scallops have a constant cross-sectional area along the length of the scallop. The individual scallops of the '181 patent design may be advantageous over a one-piece basket. Individual scallops can be installed in individual sections and can be repaired or replaced individually (as opposed to replacing the entire basket). Furthermore, if one scallop loses catalyst containment due to damage, the entire basket does not lose containment. Modular (individual section) baskets can be formed using tapered front faces made from profile wire.

[0016] In the '181 design, the end closest to the inlet nozzle may have the full cross-sectional area required for hydraulic pressure. The cross-sectional area decreases along the length to the physical minimum at the other end. This reduces the volume of the scallop by a significant amount (30%-50%). Also, the overall scallop / reactor length may be slightly reduced because the average cross-sectional area of ​​the catalyst bed increases. The reduced weight of the scallop may facilitate installation and reduce costs.

[0017] The aft enclosure plate can be contoured / tapered from the top to the bottom of the scallop. The riser sizing for pressure drop minimization and distribution at the top of the scallop is decoupled from the downstream portion of the scallop. The downstream portion of the scallop is optimized to have a gradually decreasing cross section corresponding to a volume reduction approaching a nominal 60% of the original design size. By contouring / tapering the rear enclosure section, it is also possible to maintain a flat profile wire front that establishes uniform catalyst bed depth, making new, interchangeable designs feasible for rebound or retrofit service. Because 95+% of the feed enters the riser within the scallop and is contained within the enclosed scallop, the pocket behind the contoured / tapered scallop is unaffected and the reactor can remain cylindrical.

[0018] The tapered scallops of the '181 design are installed in the reactor in a similar manner to existing scallops. When installed, they form an effective continuous outer basket that encases the catalyst bed and provides an inlet dispersion volume for vapor upstream of the catalyst bed (in the case of inlet radial flow, but the reverse in the case of outward radial flow).

[0019] The '181 design scallops provide uniformly distributed process flow across the catalyst bed in radial flow reactors. The design features a single-length profiled wire / support rod structure with closure strips to block catalyst flow into the gaps between adjacent scallops.

[0020] Another improved scallop design has been developed. The scallop comprises a vertically elongated conduit extending around the outer wall of a radial reactor. The conduit has inner and outer surfaces and a pair of opposing side surfaces.

[0021] The inner surface of the conduit (i.e., the side facing the catalyst) has openings therein, which may comprise a screen, mesh, profile wire, or the like.

[0022] In some embodiments, the inner surface of the conduit (i.e., the side facing the catalyst) comprises a plate with multiple slots. The slots must be small enough to contain a catalyst tablet. The size of the slots depends on the size of the catalyst tablet used in a particular process. The slots are typically 1 mm or less in width. The slots can extend substantially uninterrupted across the inner surface, or there can be rows of slots separated by solid portions of the plate. The term "substantially uninterrupted across the inner surface" means that the slots extend more than 70%, or more than 75%, or more than 80%, or more than 85%, or more than 90%, or more than 95% of the distance across the inner surface uninterrupted by solid portions of the plate. The slots can be cut in the plate using any suitable process, including, but not limited to, laser cutting, water jet cutting, or, in some cases for thinner plates, punching the slots into the plate.

[0023] The sides of the conduits may also be provided with plates having a plurality of openings (to a lesser extent than the interior surfaces) to allow gas flow between adjacent conduits. The openings may be slots, holes, etc. The sides may have openings covering 5-15% of the area covered by the slots in the interior surfaces.

[0024] At one end of the conduit is a riser, which can be at the top or bottom depending on the process in which the conduit is used.

[0025] The exterior surface comprises a plate that may be solid or may have one or more openings. The openings may be slots, holes, etc. Inclusion of openings in the exterior surface provides a small amount of flow to prevent back-conduit metal catalyst coking (MCC coking). MCC coking can occur when process fluids react with internal metals within the reactor.

[0026] The slotted plate conduit design may optionally include one or more structural stiffeners However, stiffeners are not required. The stiffeners strengthen the design against both radial and axial bed pressures encountered in radial flow reactor processes. These stiffeners are installed so that they extend along the vertical length of the inner surface of the conduit, perpendicular to the inner surface. The stiffeners are connected (e.g., by welding) to the inner or outer surface (or both) of the conduit. The stiffeners are typically 2-4 mm thick and are uniformly spaced to support the inner surface (catalyst-facing side) of the conduit. The stiffeners are cut to match the conduit taper (if present). The stiffeners may have slots or holes to allow gas communication between separated sections of the conduit.

[0027] This design of the structural stiffener allows the incoming process fluid flow to more completely uniformly flow before entering the separate cells of the conduit. Other inventions of this type rely on perforations along the length of the support rod, which not only add to the cost of fabrication but also reduce the structural integrity of the support rod.

[0028] In some embodiments, the stiffener extends from the top of the catalyst bed. In other embodiments, the top of the stiffener does not extend to the top of the catalyst bed. The effect of fluid distribution between the separate cells of the conduit and the location of the upper termination of the structural stiffener relative to the top of the catalyst bed was investigated using computational fluid dynamics (CFD). Results showed that having the upper termination point below the top of the catalyst bed significantly improved fluid distribution, rather than having the top of the stiffener coincide with the top of the catalyst bed. The distance below the top of the catalyst bed is generally in the range of about half to about twice the distance between the slotted inner surface and the screen on the central pipe. This translates to a range of, for example, 6 to 30.

[0029] The conduit is cheaper and lighter than prior art structures while maintaining the necessary strength.

[0030] The conduits are substantially rectangular. The inner and outer surfaces are typically straight. In some embodiments, the inner and / or outer surfaces may be curved to accommodate the curvature of the reactor wall (e.g., 360 degrees divided by the number of conduits or less).

[0031] Conduits can be tapered or non-tapered along the length of the conduit. In a tapered conduit, the distance between the inner and outer surfaces at the top is different from the distance at lower locations. The top can be wider or narrower than the bottom, depending on the design. In a non-tapered conduit, the distance between the inner and outer surfaces is constant along the length.

[0032] Non-tapered conduits are easier and cheaper to manufacture and repair than tapered designs. Additionally, non-tapered designs have more uniform vapor distribution within the catalyst bed than tapered designs.

[0033] The slotted plate scallops may be made from any suitable material, including but not limited to stainless steel.

[0034] The slotted plate / stiffener configuration allows for scalable rebound unit strength. Some units require reduced-strength scalloping due to weakened center pipes from older designs or aging. The center pipe needs to be stronger than the conduit, or failure could cause loss of catalyst containment. The conduit can be designed for various levels of strength by adjusting the number and / or thickness of the stiffeners (or removing them entirely), reducing the thickness of the faceplate, or a combination of both. This is important when customers are doing rebound retrofits where other existing equipment may limit the degree of conduit strength.

[0035] Repair work to damaged slotted front ducts will be performed using support rods / profile wires. This is much easier than a wire construction. Profile wire is not a standard product and is supplied by only a few companies, especially in the high stainless steel grades required for many processes. Furthermore, profile wire is very difficult to weld. In contrast, a slotted front is very simple to weld, source, and install over the damaged conduit.

[0036] The slotted plate design offers many improvements over prior art conduits. First, there are no closing strips or seals between adjacent conduits. This allows catalyst to fill the spaces between adjacent conduits, increasing the amount of catalyst in the reactor, which increases yield. The catalyst between the conduits is active as a result of the slots in the sides of the conduits, allowing process gas to flow into the spaces between adjacent conduits. A portion of the vapor flow exits through the slots in the sides and flows through the catalyst located between the conduits. Catalyst volume can increase by up to 10% depending on reactor geometry (e.g., up to 9%, or up to 8%, or up to 7%, or up to 6%, or up to 5%, or up to 4%, or up to 3%, or up to 2%, or 2% to 10%, or 2% to 9%, or 2% to 8%, or 2% to 7%, or 2% to 6%, or 2% to 5%, or 2% to 4%, or 3% to 10%, or 4% to 10%, or 5% to 10%, or 6% to 10%, or 7% to 10%, or 8% to 10%), which is a significant increase.

[0037] Additionally, the elimination of closure strips or sealing mechanisms simplifies installation and removal of individual conduits, reducing installation time. Closure strips and / or sealing mechanisms require extensive field installation labor, as well as field welding and inspection, which is eliminated with the slotted internal conduit design.

[0038] Conduits with slotted interior surfaces are low pressure drop. The slotted interior surface allows for a significantly lower axial frictional pressure drop down the length of the conduit compared to conduits that utilize traditional deep support rods to provide strength. The support rods add a significant amount of axial frictional pressure drop down the length of the conduit. This high axial frictional pressure drop increases steam maldistribution within the catalyst bed. Steam maldistribution can result in lower yields. It can also increase catalyst void blow and catalyst fluidization, which can increase the pressure drop within the reactor and cause unit shutdowns. In contrast, the present design features a flat plate structure without protrusions, which reduces the axial pressure drop and improves axial dispersion of process gases. This directly impacts the operating costs of a radial flow reactor.

[0039] Another advantage of the low-pressure-drop front slotted plate design is that it allows for the conduit to be designed with a smaller depth (i.e., from the inner surface to the outer surface). This is due to the fact that the axial frictional pressure drop is based on the pressure drop due to the cross-sectional area and roughness of the inside of the conduit. Because the new conduit has significantly lower roughness compared to conduits utilizing support rods, the cross-sectional area can be significantly smaller while achieving the same axial frictional pressure drop. This allows for further increases in catalyst volume. It also allows for an increase in the distance between the center pipe and the inner surface of the conduit, resulting in increased personnel access for inspection, installation, and repair work within the reactor. Typical distances within a reactor range from 10 inches to 18 inches, and increasing personnel access by an additional inch or two can substantially change accessibility. Furthermore, it allows for the new reactor to be designed with a smaller reactor diameter, reducing reactor cost, reactor weight, structure, foundation, etc., thereby reducing reactor capital costs.

[0040] The conduit is designed so that it can be manufactured in shorter lengths. These segments can be fitted together and connected at the customer site before or during installation in the reactor. The conduit can be divided into two or more segments (e.g., 2, 3, 4, 5, or more). The conduit can be made in a single piece (or more). The segments can be connected within the reactor. This reduces installation time since the rest of the reactor interior does not need to be removed to install the conduit. Furthermore, the segmented construction allows the conduit to be shipped in standard size shipping containers.

[0041] The term "plurality" means two or more.

[0042] One aspect of the invention is an apparatus within a radial reactor, in one embodiment the apparatus comprises: a vertically elongated conduit extending around an outer wall of the radial reactor, the conduit having inner and outer surfaces and a pair of opposing side surfaces, the inner surface having a plurality of slots therein and the pair of opposing side surfaces having a plurality of openings therein; and a riser at one end of the vertically elongated conduit; a vertically oriented cylindrical central pipe within the radial reactor; and a catalyst bed defined by the central pipe and the inner surface.

[0043] In some embodiments, the device further comprises at least one stiffener extending from the inner surface to the outer surface.

[0044] In some embodiments, the at least one stiffener extends vertically less than the height of the vertically elongated conduit.

[0045] In some embodiments, the at least one stiffener extends vertically from the bottom of the vertically elongated conduit to a location below the top of the vertically elongated conduit, the location being a distance in the range of one-half to two times the distance between the inner surface and the central pipe.

[0046] In some embodiments, the plurality of slots extend uninterruptedly across substantially the interior surface.

[0047] In some embodiments, the plurality of slots is divided into at least two rows of slots separated by a solid portion of the inner surface.

[0048] In some embodiments, the inner surface has more slots than the pair of opposing side surfaces.

[0049] In some embodiments, the exterior surface comprises a plate having one or more openings.

[0050] In some embodiments, the inner surface is flat, or the outer surface is flat, or both.

[0051] In some embodiments, the front-to-back distance at the top of the vertically elongated conduit is different from the front-to-back distance at a lower location on the vertically elongated conduit, and the distance from the central pipe at the top of the catalyst bed to the inner surface of the vertically elongated conduit is different from the distance measured at the lower location on the catalyst bed.

[0052] In some embodiments, the front-to-back distance at the top of the vertically elongated conduit is greater than the front-to-back distance at a lower location on the vertically elongated conduit, and the distance from the central pipe at the top of the catalyst bed to the inner surface of the vertically elongated conduit is less than the distance measured at the lower location on the catalyst bed.

[0053] In some embodiments, the apparatus further comprises a steam outlet at an opposite end of the apparatus from the riser. Prepare.

[0054] In some embodiments, the conduit includes two or more segments, each segment having at least one connector for connecting with a connector on another segment.

[0055] Another aspect of the invention is an apparatus within a radial reactor. In one embodiment, the apparatus comprises: a vertically elongated conduit extending around an outer wall of the radial reactor, the conduit having inner and outer surfaces and a pair of opposing side surfaces, the inner surface having a plurality of slots therein and the pair of opposing side surfaces having a plurality of slots therein, and a riser at one end of the vertically elongated conduit; a vertically oriented cylindrical central pipe within the radial reactor; and a catalyst bed defined by the central pipe and the inner surface.

[0056] In some embodiments, the device further comprises at least one stiffener extending from the inner surface to the outer surface.

[0057] In some embodiments, the at least one stiffener extends vertically less than the height of the vertically elongated conduit.

[0058] In some embodiments, the at least one stiffener extends vertically from the bottom of the vertically elongated conduit to a location below the top of the vertically elongated conduit, the location being a distance in the range of one-half to two times the distance between the inner surface and the central pipe.

[0059] In some embodiments, the plurality of slots extend uninterruptedly across substantially the interior surface.

[0060] In some embodiments, the plurality of slots is divided into at least two rows of slots separated by a solid portion of the inner surface.

[0061] In some embodiments, the inner surface has more slots than the pair of opposing side surfaces.

[0062] In some embodiments, the exterior surface comprises a plate having one or more openings.

[0063] In some embodiments, the inner surface is flat, or the outer surface is flat, or both.

[0064] In some embodiments, the front-to-back distance at the top of the vertically elongated conduit is different from the front-to-back distance at a lower location on the vertically elongated conduit, and the distance from the central pipe at the top of the catalyst bed to the inner surface of the vertically elongated conduit is different from the distance measured at the lower location on the catalyst bed.

[0065] In some embodiments, the front-to-back distance at the top of the vertically elongated conduit is greater than the front-to-back distance at a lower location on the vertically elongated conduit, and the distance from the central pipe at the top of the catalyst bed to the inner surface of the vertically elongated conduit is less than the distance measured at the lower location on the catalyst bed.

[0066] In some embodiments, the apparatus further comprises a steam outlet at an opposite end of the apparatus from the riser.

[0067] In some embodiments, the conduit includes two or more segments, each segment having at least one connector for connecting with a connector on another segment.

[0068] Another aspect of the invention is an apparatus. In one embodiment, the apparatus comprises a vertically elongated conduit extending around an outer wall of a radial reactor, the conduit having inner and outer surfaces and a pair of opposing side surfaces, the inner surface having a plurality of slots thereon and the pair of opposing side surfaces having a plurality of slots thereon, and a riser at one end of the vertically elongated conduit.

[0069] In some embodiments, the device further comprises at least one stiffener extending from the inner surface to the outer surface.

[0070] In some embodiments, the at least one stiffener extends vertically less than the height of the vertically elongated conduit.

[0071] In some embodiments, the at least one stiffener extends vertically from the bottom of the vertically elongated conduit to a location below the top of the vertically elongated conduit, the location being a distance in the range of one-half to two times the distance between the interior surface within the reactor and the central pipe.

[0072] In some embodiments, the plurality of slots extend uninterruptedly across substantially the interior surface.

[0073] In some embodiments, the plurality of slots is divided into at least two rows of slots separated by a solid portion of the inner surface.

[0074] In some embodiments, the inner surface has more slots than the pair of opposing side surfaces.

[0075] In some embodiments, the exterior surface comprises a plate having one or more openings.

[0076] In some embodiments, the inner surface is flat, or the outer surface is flat, or both.

[0077] In some embodiments, the front to back distance at the top of the vertically elongated conduit is different from the front to back distance at a lower location on the vertically elongated conduit.

[0078] In some embodiments, the front to back distance at the top of the vertically elongated conduit is greater than the front to back distance at a lower location on the vertically elongated conduit.

[0079] In some embodiments, the apparatus further comprises a steam outlet at an opposite end of the apparatus from the riser.

[0080] In some embodiments, the conduit includes two or more segments, each segment having at least one connector for connecting with a connector on another segment.

[0081] 1-3 illustrate different embodiments of a conduit. In FIG. 1, conduit 100 has an inner surface 105, an outer surface 110, and a pair of opposing side surfaces 115. Conduit 100 has two stiffeners 120 extending between inner surface 105 and outer surface 110. Inner surface 105 includes a plurality of slots 125. As shown, the plurality of slots 125 are arranged in three rows separated by two solid portions of inner surface 105. The plurality of slots 125 in side surfaces 115 are arranged in three rows separated by two solid portions of inner surface 105. There are 35.

[0082] 2 illustrates another embodiment of the conduit 100. In this embodiment, there are three stiffeners 120. The plurality of slots 125 are arranged in four rows separated by three solid portions 130 of the inner surface 105.

[0083] 3, the plurality of slots 125 extend across the inner surface 105. There are no solid portions separating the plurality of slots 125.

[0084] FIG. 4 illustrates how catalyst bed depth varies from top to bottom, providing increased catalyst volume within the reactor when tapered conduits are used. In reactor 200, reactor shell 205 is shown. In an embodiment of the invention, steam 210 is shown entering riser 215 through opening 220. Conduit 225 has a slotted inner surface 230, an outer surface 235, and a side surface 237 with slots 239. In some embodiments, catalyst bed 240 is shown between slotted inner surface 230 and surface 245, which may be a screen material. Catalyst bed 240 has diameters of varying sizes, with D2 equal to or greater than D1, and D3 equal to or greater than the diameter taken at the top of catalyst bed 240. Also shown in FIG. 4 is radially flowing steam 250, shown circulating upward as steam stream 255 within central pipe section 260 of reactor 200.

[0085] 5A-5D illustrate various embodiments of segmented structures. 5A and 5B show front and side views of a two-segment conduit 300. The two-segment conduit 300 includes a first segment 305 and a second segment 310. The first segment 305 has a connector 315 for mating with a connector 320 on the second segment 310. 5C and 5D show front and side views of a three-segment conduit 400. The three-segment conduit 400 includes a first segment 405, a second segment 410, and a third segment 415. The first segment 405 has a connector 420 for mating with a connector 425 on the second segment 410. The second segment 410 has a connector 430 for mating with a connector 435 on the third segment 415.

[0086] Specific Embodiments While the following is described in conjunction with specific embodiments, it will be understood that this description is illustrative and not intended to limit the scope of the foregoing description and the appended claims.

[0087] A first embodiment of the present invention is an apparatus within a radial reactor, the apparatus comprising: a vertically elongated conduit extending around the outer wall of the radial reactor, the conduit having inner and outer surfaces and a pair of opposing side surfaces, the inner surface having a plurality of slots therein and the pair of opposing side surfaces having a plurality of openings therein; and a riser at one end of the vertically elongated conduit; a vertically oriented cylindrical central pipe within the radial reactor; and a catalyst bed defined by the central pipe and the inner surface. This embodiment of the present invention is any one, any, or all of the previous embodiments to the first embodiment in this section, further comprising at least one stiffener extending from the inner surface to the outer surface. This embodiment of the present invention is any one, any, or all of the previous embodiments to the first embodiment in this section, wherein the at least one stiffener extends vertically less than the height of the vertically elongated conduit. An embodiment of the present invention is any one, any or all of the previous embodiments in this section to the first embodiment in this section, wherein the at least one stiffener extends vertically from a bottom of the vertically elongated conduit to a location below an upper portion of the vertically elongated conduit, the location being half the distance between the inner surface and the central pipe. The distance is between 100 and 200 mm. An embodiment of the present invention is any one, any, or all of the previous embodiments to the first embodiment in this section, wherein the plurality of slots extend substantially uninterrupted across the inner surface. An embodiment of the present invention is any one, any, or all of the previous embodiments to the first embodiment in this section, wherein the plurality of slots are divided into at least two rows of slots separated by a solid portion of the inner surface. An embodiment of the present invention is any one, any, or all of the previous embodiments to the first embodiment in this section, wherein the inner surface has more slots than a pair of opposing side surfaces. An embodiment of the present invention is any one, any, or all of the previous embodiments to the first embodiment in this section, wherein the outer surface comprises a plate having one or more openings. An embodiment of the present invention is any one, any, or all of the previous embodiments to the first embodiment in this section, wherein the inner surface is flat, the outer surface is flat, or both. An embodiment of the present invention is any one, any, or all of the previous embodiments in this section to the first embodiment in this section, wherein the front-to-back surface distance at the top of the vertically elongated conduit is different from the front-to-back surface distance at a lower location on the vertically elongated conduit, and wherein the distance from the central pipe at the top of the catalyst bed to the inner surface of the vertically elongated conduit is different from the distance measured at the lower location of the catalyst bed. An embodiment of the present invention is any one, any, or all of the previous embodiments in this section to the first embodiment in this section, wherein the front-to-back surface distance at the top of the vertically elongated conduit is greater than the front-to-back surface distance at a lower location on the vertically elongated conduit, and wherein the distance from the central pipe at the top of the catalyst bed to the inner surface of the vertically elongated conduit is less than the distance measured at the lower location of the catalyst bed. An embodiment of the present invention is any one, any, or all of the previous embodiments in this section to the first embodiment in this section, further comprising a steam outlet at an end of the apparatus opposite from the riser.An embodiment of the present invention is one, any, or all of the previous embodiments in this section to the first embodiment in this section, wherein the conduit includes two or more segments, each segment having at least one connector for connecting with a connector on another segment.

[0088] A second embodiment of the present invention is an apparatus within a radial reactor, the apparatus comprising: a vertically elongated conduit extending around the outer wall of the radial reactor, the conduit having inner and outer surfaces and a pair of opposing side surfaces, the inner surface having a plurality of slots therein and the pair of opposing side surfaces having a plurality of openings therein; and a riser at one end of the vertically elongated conduit; a vertically oriented cylindrical central pipe within the radial reactor; and a catalyst bed defined by the central pipe and the inner surface. This embodiment of the present invention is any one, any, or all of the previous embodiments through the second embodiment in this section, further comprising at least one stiffener extending from the inner surface to the outer surface. This embodiment of the present invention is any one, any, or all of the previous embodiments through the second embodiment in this section, wherein the at least one stiffener extends vertically less than the height of the vertically elongated conduit. An embodiment of the present invention is any one, any, or all of the previous to second embodiments in this section, wherein the outer surface comprises a plate having one or more openings. An embodiment of the present invention is any one, any, or all of the previous to second embodiments in this section, wherein the front-to-back distance at the top of the vertically elongated conduit is different from the front-to-back distance at a lower location on the vertically elongated conduit, and the distance from the central pipe at the top of the catalyst bed to the inner surface of the vertically elongated conduit is different from the distance measured at the lower location on the catalyst bed. An embodiment of the present invention is any one, any, or all of the previous to second embodiments in this section, further comprising a steam outlet at an opposite end of the apparatus from the riser. An embodiment of the present invention is any one, any, or all of the previous to second embodiments in this section, wherein the conduit comprises two or more segments, each segment having a connector on another segment. The device has at least one connector for connecting to the

[0089] A third embodiment of the present invention is an apparatus within a radial reactor, the apparatus comprising: a vertically elongated conduit extending around the outer wall of the radial reactor, the conduit having inner and outer surfaces and a pair of opposing side surfaces, the inner surface having a plurality of slots therein and the pair of opposing side surfaces having a plurality of openings therein, and a riser at one end of the vertically elongated conduit. This embodiment of the present invention is any one, any, or all of the previous embodiments through the third embodiment in this section, further comprising at least one stiffener extending from the inner surface to the outer surface. This embodiment of the present invention is any one, any, or all of the previous embodiments through the third embodiment in this section, wherein the at least one stiffener extends vertically less than the height of the vertically elongated conduit. This embodiment of the present invention is any one, any, or all of the previous embodiments through the third embodiment in this section, wherein the outer surface comprises a plate having one or more openings. An embodiment of the present invention is any one, any, or all of the previous embodiments through the third embodiment in this section, wherein the front-to-back distance at an upper portion of the vertically elongated conduit is different from the front-to-back distance at a lower location on the vertically elongated conduit.An embodiment of the present invention is any one, any, or all of the previous embodiments through the third embodiment in this section, further comprising a steam outlet at an opposite end of the apparatus from the riser.An embodiment of the present invention is any one, any, or all of the previous embodiments through the third embodiment in this section, wherein the conduit includes two or more segments, each segment having at least one connector for connecting with a connector on another segment.

[0090] Without further elaboration, it is believed that one skilled in the art can, using the preceding description, readily ascertain the essential characteristics of the present invention and make various changes and modifications to the present invention to adapt it to various uses and conditions, all without departing from the spirit and scope of the present invention. The preceding preferred specific embodiments are, therefore, to be construed as merely illustrative, and not limitative of the remainder of the disclosure in any way, and are intended to cover various modifications and equivalent arrangements included within the scope of the appended claims.

[0091] Above, all temperatures are listed in degrees Celsius and all parts and percentages are by weight unless otherwise stated. [Form 1] An apparatus in a radial reactor (200), comprising: a vertically elongated conduit (225) extending around the outer wall of the radial reactor, the conduit (225) having an inner surface (230) and an outer surface (235) and a pair of opposing side surfaces (237), the inner surface (230) having a plurality of slots therein and the pair of opposing side surfaces (237) having a plurality of openings (239) therein; and a riser (215) at one end of the vertically elongated conduit (225); a vertically oriented cylindrical central pipe (260) within said radial reactor (200); a catalyst bed (240) defined by said central pipe (260) and said inner surface. [Form 2] 10. The device of claim 1, further comprising at least one stiffener (120) extending from the inner surface (105) to the outer surface (110). [Form 3] 3. The apparatus of claim 2, wherein the at least one stiffener (120) extends vertically less than the height of the vertically elongated conduit (100). [Form 4] 4. The device of any one of claims 1 to 3, wherein the plurality of slots (125) extend uninterrupted substantially across the inner surface (105) or the plurality of slots (125) are divided into at least two rows of slots (125) separated by a solid portion of the inner surface (105). [Form 5] The device according to any one of the preceding aspects, wherein the inner surface (105) has more slots (125) than the pair of opposing side surfaces (115). [Form 6] 4. The apparatus of any one of the preceding embodiments, wherein the outer surface (110) comprises a plate having one or more openings. [Form 7] 4. The apparatus according to any one of the preceding claims, wherein the distance from the inner surface (230) to the outer surface (235) at the top of the vertically elongated conduit (225) is different from the distance from the inner surface (230) to the outer surface (235) at a lower location on the vertically elongated conduit (225), and the distance from the central pipe (260) to the inner surface (230) of the vertically elongated conduit (225) at the top of the catalyst bed (240) is different from the distance measured at the lower location on the catalyst bed (240). [Form 8] 8. The apparatus of claim 7, wherein the distance from the inner surface (230) to the outer surface (235) at the upper part of the vertically elongated conduit (225) is greater than the distance from the inner surface (230) to the outer surface (235) at the lower part of the vertically elongated conduit (225), and the distance from the central pipe (260) at the upper part of the catalyst bed (240) to the inner surface (230) of the vertically elongated conduit (2250) is less than the distance measured at the lower part of the catalyst bed (240). [Form 9] 4. The apparatus of any one of embodiments 1 to 3, further comprising a vapor outlet at an opposite end of the apparatus from the riser. [Form 10] The device of any one of aspects 1 to 3, wherein the conduit (300) includes two or more segments (305, 310), each segment (305) having at least one connector (315) for connecting with a connector (320) on another segment (310).

Claims

1. An apparatus in a radial reactor (200), comprising: a vertically elongated conduit (225) extending around the outer wall of the radial reactor, the conduit (225) comprising an inner surface (230) and an outer surface (235) and a pair of opposing side surfaces (237), the inner surface (230) having a plurality of slots therein, the pair of opposing side surfaces (237) having a plurality of openings (239) therein, the pair of opposing side surfaces (237) having openings covering 5 to 15% of the slot area in the inner surface; and a riser (215) at one end of the vertically elongated conduit (225); a vertically oriented cylindrical central pipe (260) within said radial reactor (200); a catalyst bed (240) defined by said central pipe (260) and said interior surface; and at least one stiffener (120) extending from said inner surface (105) to said outer surface (110).

2. 2. The apparatus of claim 1, wherein the plurality of slots (125) extend uninterrupted substantially across the inner surface (105) or the plurality of slots (125) are divided into at least two rows of slots (125) separated by a solid portion of the inner surface (105).

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