REACTOR DISTRIBUTION APPARATUS AND QUENCH ZONE MIXING APPARATUS

Abstract: A quench zone mixing apparatus that occupies a low vertical height and has an improved mixing efficiency and fluid distribution across the catalyst surface includes a swirl chamber (20), a rough distribution network (100), and a distribution apparatus (120). In the swirl chamber (20), reactant fluid from a catalyst bed above is thoroughly mixed with a quench fluid by a swirling action. The mixed fluids exit the swirl chamber (20) through an aperture to the rough distribution network (100) where the fluids are radially distributed outward across the vessel to the distribution apparatus (120). The distribution apparatus (120) includes a plate (122) with a number of bubble caps (130) and associated drip trays (150) that multiply the liquid drip stream from the bubble caps to further symmetrically distribute the fluids across the catalyst surface. The distribution apparatus (120) can be used in the reaction vessel without the swirl chamber (20) and rough distribution network (100), e.g., at the top of a vessel.

Description: REACTOR DISTRIBUTION APPARATUS AND QUENCH ZONE MIXING APPARATUS BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a distribution apparatus and a quench zone mixing apparatus (or device) that may include die distribution apparatus, both of which are suitable for efficiently mixing and redistributing reactants across the horizontal cross-section of a vertical reaction vessel. Discussion of Related Art Many catalytic processes are carried out in reactors that contain a series of separated catalytic beds. Frequently, in such processes, quench zone mixing devices are advantageously located to provide rapid and efficient mixing of the fluid streams being processed in die reactor with a cooler fluid stream supplied from an external source. Consequently, the temperature of the process stream entering the successive catalyst beds can be controlled. One skilled in the art will appreciate that the better the mixing of the reactant streams, the better the temperature and reaction can be controlled. As a result, die overall performance of die reactor will be better. Examples of quench zone mixing devices include U.S. Pat. No. 3,353,924, U.S. Pat. No. 3,541,000, U.S. Pat. No. 4,669,890, and U.S. Pat. No. 5, 152,967. Some of u ese devices are complicated and are prone to plugging. Others need a relatively large vertical space to ensure the desired degree of mixing. Still others create an undesirably high pressure drop. Consequently, there is a continuing need for a suitable quench zone mixing device that can efficiently mix fluid streams in a low vertical space with an acceptably low pressure drop. Typically, the quench zone mixing devices are located above an associated fluid distribution system; for example, a horizontally disposed distribution plate or tray. The distribution plate collects die fluid (vapor and liquid), uniformly distributes it across the plate and discharges the fluid on to the catalyst bed. Such distribution tray may contain a number of "bubble cap" assemblies which may be disposed over one or more openings in die distribution tray. The bubble cap provides intimate mixing of die vapor and liquid before die mixed phase fluid is distributed across the catalyst bed. Examples of distribution trays include U.S. Pat. No. 2,778,621, U.S. Pat. No. 3,218,249, U.S. Pat. No. 4,960,571, U.S. Pat. No.4,836,969, U.S. Pat. No. 5,045,247, and U.S. Pat. No. 5, 158,714. AUhough one or more of these designs may be acceptable, mere is still room for improvement, particularly in providing a uniform distribution of vapor and liquid phases into contact with the catalyst in the reactor vessel. SUMMARY OF THE INVENTION It is an object of the invention to provide a distribution apparatus that includes a redistribution tray (also referred to herein as a "redistribution plate"). It is another object of d e invention to provide a quench zone mixing apparatus (also referred to herein as d e "quench zone mixing device") that includes a swirl chamber, a rough distribution network disposed underneath me swirl chamber, and, preferably, a distribution apparatus disposed underneath the rough distribution network. It is to be understood that d e distribution apparatus can be associated with d e quench zone mixing device or can be used separately from the quench zone mixing device; for example, at the top of die reactor vessel. The distribution apparatus includes a redistribution plate (also referred to herein as a "plate") having a plurality of apertures and a plurality of bubble caps with at least some of the bubble caps associated with at least some of the apertures. In a preferred embodiment, a plurality of drip trays are substantially horizontally disposed underneath the redistribution plate. At least some of the drip trays are associated with at least some of the bubble caps. The drip trays receive fluids exiting the associated bubble caps and distribute diem dirough at least one discharge port provided on die bottom of die drip tray. In a more preferred embodiment, the drip trays have at least two discharge ports to multiply the fluid drip stream received from the bubble cap and symmetrically distribute the fluid across the catalyst surface. As noted above, die quench zone mixing apparatus includes a swirl chamber. The swirl chamber is adapted to receive fluids from upstream of die reactor (such as those exiting a catalyst bed located above die swirl chamber). Preferably, die swirl chamber is substantially cylindrical. The swirl chamber includes a wall disposed between a ceiling and a floor. The wall has a plurality of openings, such as inlet openings, that provide a means of fluid communication into the swirl chamber. The floor surrounds an orifice, which provides a means for fluid to exit me swirl chamber. Preferably, a weir is provided about die periphery of the orifice. The rough distribution network is disposed beneath the swirl chamber to receive fluids from die swirl chamber. The rough distribution network includes a splash plate and radially outwardly extending channels. The splash plate is adapted to collect fluids from die swirl chamber and radially outwardly distribute them through die channels. Preferably, d e channels include side walls with spaced apart notches to allow fluid to exit die channels. Fluids exiting the channels fall onto a distribution apparatus disposed beneath me rough distribution network. Preferably, the distribution apparatus includes die redistribution plate substantially horizontally mounted below die rough distribution network and the swirl chamber. The redistribution plate extends substantially across die entire cross-section of die vessel to separate an upper section of the vessel from a lower section. The redistribution plate comprises a plurality of apertures and a plurality of bubble caps associated witi d e apertures of the redistribution plate. More preferably, a bubble cap is associated with each aperture to provide de sole means of fluid flow dirough the plate. The bubble caps include a riser and a spaced apart cap. The riser has a top and a bottom and the riser is secured near the bottom to die redistribution plate. A passageway is defined between the top and bottom and provides a means of fluid communication across die redistribution plate. Preferably, die cap has a plurality of spaced apart slots to allow d e flow of vapor through d e cap and into d e annulus defined by die cap and the riser. In a preferred embodiment, die ceiling of die swirl chamber is closed. Preferably, a frusto-conical shaped liquid collection tray surrounds die swirl chamber and is sloped so that die one end adjacent the inlet openings is lower than the otiier end adjacent to the vessel wall. Fluid exiting the preceding catalyst bed falls onto the liquid collection tray or onto die ceiling of die swirl chamber where it is directed onto die liquid collection tray and through die inlet openings. Baffles are located inside the swirl chamber adjacent the openings and in communication with the openings to receive and direct incoming fluid circumferentially about the swirl chamber. In this preferred embodiment, the orifice is centrally located and provides me sole means for fluid to exit the swirl chamber. In another preferred embodiment, a quench fluid system is provided to introduce quench fluid into die swirl chamber. The quench fluid system includes a feed pipe in communication with a concentric manifold that surrounds the swirl chamber. A plurality of quench fluid laterals in fluid communication with the manifold extend radially inward and terminate with nozzles that extend into the swirl chamber. The nozzles are located adjacent and below the baffles and have openings to direct quench fluids into the fluid stream exiting the baffles. In another embodiment of the present invention, a reactor is provided with the quench zone mixing apparatus of the present invention interposed between two catalyst beds. Preferably, the quench zone mixing apparatus is supported within a vessel of the reactor by a support structure that includes a concentric hub, which may be formed to act as a torsion tube, and at least a first set of radial beams extending radially outward from the hub and terminating at a support ring that is attached to die reactor vessel wall. In particular, the radial beams comprise a flange that supports the redistribution tray and a web of die beams preferably includes a plurality of openings to allow die passage of fluids across the vessel. In addition, the webs also carry the channels. The radial beams also support the swirl chamber and, in the area between die wall of the swirl chamber and die vessel wall, me radial beams have a vertical height that slopes downward from de vessel wall to die swirl chamber wall. Specifically, the radial beams at die swirl chamber wall have a vertical height at about the bottom of die openings on die swirl chamber wall and at die vessel wall the radial beams have a vertical height greater than at die swirl chamber wall. The liquid collection tray is provided on e top of die radial beams in the area between the swirl chamber wall and d e vessel wall to create a downwardly sloping conical surface. As in other embodiments, die liquid collection tray is preferably frusto-conical shaped and it surrounds the swirl chamber. Alternatively, a first set of radial beams having a single vertical height may be provided witii a second set of radial beams located vertically above the first set. In this case, the top of the second set of radial beams is downwardly sloped in the same fashion as described above. In either case, the liquid collection tray collects fluid from the ceiling of the swirl chamber and from the catalyst bed above and directs it through the openings in die swirl chamber. In a preferred embodiment, a first set of radial beams having a single vertical height is used to support die swirl chamber and distribution channels. Addi¬ tionally, a support ring is attached to die outside wall of the swirl chamber at a location just below die inlet openings. A second support ring is attached to the vessel wall at a location approximately equal to the elevation of the swirl chamber ceiling. The liquid collection tray is provided on top of die support rings in the area between the vessel wall and the swirl chamber to preferably create a frusto-conical shape tiiat directs fluids from the catalyst bed above toward die swirl chamber inlet openings. The ring at die wall provides support for die liquid collection tray and a sealing surface to prevent fluids from bypassing the swirl chamber. The present invention also contemplates an improvement in known quench zone mixing devices wherein a rough distribution network is interposed between a mixing chamber (or a swirl chamber) and a distribution apparatus. The present invention therefore provides a reactor diat includes die quench zone mixing apparatus of this invention, which comprises a mixing chamber and a distribution apparatus. In particular, die improvement comprises a rough distribution network disposed between die mixing chamber and die distribution apparatus, the rough distribution network comprising a splash plate in fluid communication with outwardly extending channels. Preferably, de channels extend outward radially from the splash plate. The splash plate preferably has apertures and die channels preferably include side walls with spaced apart notches to allow fluid to exit die channels. The present invention also contemplates the use of a distribution apparatus where die distribution apparatus is not associated with d e quench zone mixing apparatus i.e. , die distribution apparams is used in addition to die quench zone mixing apparatus or used in a reactor that does not have a quench zone mixing apparams. In this embodiment, the distribution apparams may be provided above a catalyst bed. For example, the distribution apparatus may be provided at the top of the reactor or between successive catalyst beds. The distribution apparatus will include a redistribution plate and a plurality of bubble caps, as described above. n addition, the distribution apparams may also be provided with a plurality of drip trays, as described above. In this embodiment, die distribution apparatus is usually called a "distribution tray". The present invention also contemplates the use of a quench zone mixing apparatus in a process for contacting a first fluid with a second fluid, wherein the first and second fluids may be liquid or gas. Preferably, the process occurs in a portion of a reactor between two successive spaced apart beds of particle form solids, e.g. , catalyst panicles. In one embodiment, die invention broadly includes introducing a first fluid into the reactor; transporting the first fluid through a first catalyst bed; collecting the reaction product from die first catalyst bed and transporting it through the quench zone mixing device where it is further mixed and reacted with a quench fluid ("second fluid") to foπn a further reaction product mat is distributed onto die surface of a second bed, including catalyst particles, located downstream from the first catalyst bed. In one particular application of this embodiment, hydrotreating and hydrocracking of relatively heavy petroleum hydrocarbon stocks, the first fluid is a hot mixture of gas and liquid and die second fluid is a cold gas. In a particular embodiment, die process is directed to a two phase downflow reactor. The process includes introducing a first fluid, such as liquid and gas reactants, into the reactor at a location above a swirl chamber. Preferably, die first fluid is introduced in an upper section of the reactor. The first fluid is men introduced into d e swirl chamber. A second fluid, e.g., a quench gas, is introduced into d e swirl chamber and contacts d e first fluid to form a swirl chamber fluid mixture. The swirl chamber fluid mixture exits die swirl chamber and is collected by a rough distribution network where the swirl chamber fluid mixture is radially distributed over a splash plate and outwardly extending channels. Subsequendy, a fluid mixture exiting die channels is conducted to a distribution apparams. The distribution apparatus includes a redistribution plate witii a plurality of apermres and a plurality of bubble caps witii at least some of the bubble caps associated with at least some of die apertures. The fluid mixture is transported through the redistribution plate to form a redistribution plate fluid mixture. The redistribution plate fluid mixture is eventually transported to a downstream section of the reactor. In a preferred embodiment of die process, before the redistribution plate fluid mixture is transported to die downstream section of the reactor, it is collected on a plurality of substantially horizontal drip trays with at least some of the drip trays which are located underneath the plate and associated witii at least some of the bubble caps. The collected redistribution plate fluid mixture is distributed through at least one discharge port in die drip trays and some separation of die gas from the liquid takes place on the drip trays. The invention is also directed to a process for transferring a fluid from a first bed of a reactor to a second bed of a reactor, located downstream from the first bed. The process comprises introducing a fluid from d e first bed of die reactor into a swirl chamber. Subsequently, die fluid is removed from die swirl chamber, and is introduced into a rough distribution network including a splash plate and outwardly extending channels. Then, the fluid is conducted from the rough distribution network to a distribution apparatus, which includes a redistribution plate with a plurality of apertures and a plurality of bubble caps. At least some of die bubble caps are associated with at least some of the apermres. The fluid is then transported dirough die redistribution plate to the second bed of die reactor. The fluid may include a liquid or a mixture of liquid and gas. A quench fluid, liquid or gas, may also be introduced separately into die swirl chamber. The invention is also directed to a process for redistributing a fluid within a reactor. The process includes collecting the fluid on a distribution apparams and distributing die fluid to a downstream section of die reactor in a substantially even fashion across the cross-section of die reactor. The distribution apparatus includes a redistribution plate with a plurality of apertures and a plurality of bubble caps with at least some of the bubble caps associated with at least some of the apertures. In a preferred embodiment, a plurality of substantially horizontal drip trays are located underneath die plate and associated witii at least some of the bubble caps. Consequendy, the fluid is collected on die surface of die redistribution plate, transported through the plate, preferably, onto the drip trays where it is transported to a downstream section of tbe reactor. The apparatus and process of the present invention may be particularly applicable for use in fixed bed catalytic processing systems for hydrotreating and hydrocracking of relatively heavy petroleum hydrocarbon stocks. Such processing systems may use reactors with one or more vertically spaced catalyst beds. Although the invention may be particularly applicable for use in hydrogen treatment of hydrocarbons, die process and apparatus are not limited to such use and can be used in any system where the mixture of a vertically flowing liquid and a vertically flowing gas, or a lighter liquid and heavier liquid, is desired. For example, the invention may also be used in aromatic saturation, catalytic dewaxing and hydrofinishing operations. The quench zone mixing apparatus may be placed in any suitable location in a reactor vessel. For example, it may be placed at die top of die reactor, so that any fluid entering the reactor will contact the quench zone mixing apparatus before it contacts any other internal reactor devices. Alternatively, the quench zone mixing apparatus may be placed downstream from any internal reactor devices, such as internal catalyst beds. For purposes of exemplification and illustration, a range of parameters is given below for some specific processing systems for hydrotreating and hydrocracking relatively heavy petroleum hydrocarbon stocks in which die apparatus and process of die present invention can be used. Such processing systems typically use reactors having inside diameters of 5 to 20 feet with about 2 to 5 vertically spaced catalyst bed spaces with lengths of 5 to 50 feet, and use catalysts typically having particle sizes of 1/32 inch to 1/4 inch. As pointed out in greater detail below, d e quench zone mixing apparatus of this invention provides important advantages. The design of d e invention apparatus minimizes the overall vertical height of the quench zone mixing apparatus. As a result, die overall vertical height of the reaction vessel can be decreased, diereby reducing die capital cost of the vessel. At the same time, intimate mixing and tiiermal equilibration is achieved while maintaining only a moderate pressure drop across die device. The teπn "fluid" as used in the specification and claims is meant to include bodi liquids and gases. The term "vapor" and "gas" are used interchangeably herein. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 shows a multi-bed catalytic reactor with a portion cut away to show a vertical section view of a portion of die distribution apparatus and die quench zone mixing apparatus of the present invention. Figure 2 is a perspective view of a portion of die quench zone mixing and distribution apparatus witii several portions removed to better show the detail of d e apparatus. It is understood that the portion of die quench zone mixing apparatus not shown is identical to the portion shown. Figure 2A is a perspective view of a portion of the quench zone mixing and distribution apparams showing a different embodiment of portions of the quench zone mixing apparatus. Several portions have been removed to better show the detail of the apparatus. Figure 2B is a perspective view of a portion of the quench zone mixing and distribution apparams showing yet another different embodiment of portions of the quench zone mixing apparatus. Several portions have been removed to better show the detail of die apparatus. Figure 2C is a perspective view of a portion of die quench zone mixing and distribution apparatus showing a different embodiment of the apparatus. Several poπions have been removed to better show die detail of d e apparatus. Figure 2D is an end view of a radial support beam and distribution channel of die rough distribution network of die embodiment of Figure 2C. Figure 3 is a perspective view of a portion of die swirl chamber of die quench zone mixing apparatus with several portions removed to show die detail of die swirl chamber. It is understood tiiat die portion of die swirl chamber not shown is identical to the portion shown. Figure 4A is a top view of a portion of die quench zone mixing apparatus to show die quench fluid system. It is understood diat die portion of die quench fluid system not shown is identical to die portion shown. Figure 4B is a cross-sectional view of a poπion of the quench fluid system. Figure 5 A is top view of a poπion of the quench zone mixing apparatus to show further detail of the rough distribution network. It is understood that the poπion not shown is identical to die portion shown. Figure 5B is a partial cross-sectional view of a portion of the quench zone mixing apparams to show further detail of die distribution channels and redistribution tray. It is understood that the portion not shown is identical to the portion shown. Figure 5C is an end view of a radial suppoπ beam and distribution channel of die rough distribution network. Figure 6A is a perspective view of the redistribution tray used in the distribution apparatus of the present invention. For clarity, many of the individual bubble caps are not shown. Figure 6B is a perspective view of an individual bubble cap associated witii an aperture of the redistribution tray of FIG. 6A and widi its drip tray. Poπions are cut-away to show die detail of die bubble cap and drip tray. Figure 7 is a perspective view of an alternative embodiment of the drip tray as shown in FIG. 6B illustrating a plurality of drip guides. Figure 8 is a perspective view of an alternative embodiment of die drip tray shown in FIG. 6B illustrating an alternative bottom construction. Figure 9 is a perspective view of an alternative embodiment of die drip tray that may be useful in die apparatus of the present invention. DETAILED DESCRIPTION OF THE INVENTION AND PREFERRED EMBODIMENTS The quench zone mixing apparatus invention will now be described with reference to its use in a multi-bed, catalytic reactor in which the apparatus is located in a zone between two catalytic beds. It is understood by one skilled in die an that the apparatus of die present invention can also be used in non-catalytic vessels or reactors. As shown in FIG. 1, the reactor 10 comprises a cylindrical vessel. While die vessel is preferably substantially cylindrical, it can also have any shape that is suitable for manufacturing concerns. The vessel is typically constructed of corrosion resistant metal or an equivalent material such as stainless steel, weld overlayed chrome alloy steels, or the like. The vessel is noπnally insulated internal'y or externally for operation at elevated temperatures. Typically, an inlet 12 is provided in the vessel at its top poπion for convenience in filling the vessel with catalyst, for routine maintenance, or for flow of fluid, as dictated by the particular application. An outlet 14 is provided in the vessel at its bottom portion to permit die discharge of die fluid product. Fluid quench is typically admitted to d e vessel dirough a side wall nozzle 13 connected to a quench feed pipe. Alternatively, quench fluid may be introduced dirough die top or bottom of the reactor. A cut-away poπion 17 illustrates a partial vertical section view of the distribution apparams and the quench zone mixing apparams. Interposed between one or more successive catalyst beds is d e quench zone mixing apparatus 16 of the present invention. The apparatus includes a swirl chamber 20, a rough distribution network 100 and, preferably a distribution apparatus 120. The swirl chamber 20 receives and mixes a quench fluid, typically from an external source, with a reactant process fluid stream ("process fluid", "process stream" or "reactant fluid") exiting from die catalyst bed above. The quench fluid may have a temperature different from die process fluid and may be introduced to control die temperature of the process fluid. The quench fluid may also be added to adjust the composition of die process stream. The rough distribution network (or system) 100 collects a product stream from the swirl chamber ("swirl chamber product stream") and radially outwardly distributes it to the distribution apparatus. The distribution apparatus 120 includes a redistribution plate 122 (or a plate 122), a number of bubble caps 130, and a number of associated drip trays 150. When the distribution apparams is a part of the quench zone mixing apparatus, the distribution apparatus collects the fluid from the rough distribution system and die swirl chamber. The fluid is then further mixed by mutual entrainment of the gas and liquid in die bubble caps. The fluid stream exiting die bubble caps is subdivided by die drip trays associated with individual bubble caps to provide a substantially symmetrical and uniform flow distribution of fluid across the catalyst surface. As also shown in FIG. 1, die distribution apparatus 120 described above need not be associated widi die quench zone mixing apparatus but may be provided in the reactor, e.g. near die top of die reactor to provide for uniform flow distribution to a downstream section of the reactor. When the distribution apparatus is provided in this manner, it will collect fluid from above, further mix the fluid, and uniformly distribute die fluid. Referring now to FIG. 2, a portion of die quench zone mixing apparatus of die present invention is shown. The apparatus fills substantially the entire cross-section of die vessel and is supported by a support structure 60. The suppoπ structure has the shape of a wagon wheel with a central hub and radial support beams as spokes. The entire structure is supported in the reactor by a single support ring 62, secured to die inside of die vessel wall by welding, forging or other means. The radial suppoπ beams lower flanges 70 are notched at the wall end so a web 68 of die radial suppoπ beams 66 will fit on die support ring. The top of de suppoπ beam lower flange 70 and die top of the wall suppoπ ring 62 are at the same elevation to facilitate installation and sealing of the redistribution tray. The suppoπ beams can be bolted to positioning lugs (not shown) attached to die wall to provide stability. A central hub 64, concentric with die reactor, may be sized as a manway for maintenance in the vessel. A first set of radial beams 66 extends radially outward from the central hub to the support ring 62. The radial beams 66 have a flange 70 for supporting the redistribution plate 122. Preferably, each beam 66 is I-shaped and its web 68 has a number of openings 72 near the redistribution plate to allow die transverse passage of fluids around die reactor. The central hub may be constnicted of any suitable materials. For example, it can be comprised of hub rings 63, as illustrated in Figure 2B, an annulus 105, which may include internal hub rings, as illustrated in Figure 2A, or of one or more torsion mbes (each having a cylindrical shape) extending substantially from top to bottom of radial beams (not illustrated in die drawings). If a torsion mbe design is used, die end of the support beams is welded to the torsion mbe or mbes. The construction of die hub illustrated in Figure 2 is preferred. Referring now to FIG. 3, a squat swirl chamber 20 is supported by the suppoπ structure. Preferably, the swirl chamber is cylindrical. The swirl chamber has a floor 22 and an orifice 24. Preferably, the floor consists of a solid plate surrounding a central orifice 24. A round weir 26 rises above the orifice 24 to define a shallow basin on the floor inside the swirl chamber. The swirl chamber has a ceiling 28 that preferably consists of a solid plate (best seen in FIG. 4B). A section of the swirl chamber ceiling and floor may be constructed so that they can be removed to serve as a manway for maintenance purposes. The side wall 30 of the swirl chamber cylinder is solid except for a number of openings 32 spaced around the circumference and located just below the ceiling. Preferably, the openings are evenly spaced around the circumference of die chamber and have a parallelogram shape and, more preferably are rectangular. Most preferably, the openings are square. In die most preferred embodiment, die openings provide d e sole means for a fluid from an upstream section of die reactor to enter the swirl chamber. The upstream section of the reactor may include a catalyst bed. As shown in FIG. 2, a second set of radial beams 74 extends radially outward from die swirl chamber wall toward die reactor wall 11. Preferably, they are located on top of and are fastened to die first set of radial beams 66 to provide a rigid structure. Alternatively, a single beam (or a single set of beams) with the same profile as the two beams could be used (e.g., see Fig. 2C). Throughout die specification, while specific reference is made to a second set of radial beams, one skilled in the an will appreciate diat a single beam can be equivalently used. The second set of radial beams is taller at the reactor wall than at the swirl chamber. At the swirl chamber wall, die beams have substantially die same height as die bottom of the openings on die wall of the swirl chamber. As a result, die top of die second set of beams is downwardly sloped. In a preferred embodiment shown in FIG. 2A, die second set of radial beams can be replaced by a first ring 79 attached to die outside wall of die swirl chamber adjacent die bottom 34 of the openings 32 and a second ring 77 attached to die reactor wall at a higher elevation tiian die first ring. More preferably, the second ring 77 is attached at an elevation about equal to die ceiling of the swirl chamber. In this embodiment, the central hub 64 includes an annulus 105, extending from the top to the bottom of die hub. The annulus comprises openings 107 which enable fluid to flow out to die distribution channels and then onto die redistribution plate, below the splash plate. The annulus may include internal hub rings (not shown in Fig. 2A). Openings 101 are provided to allow fluid to flow into or out of die central hub, and to allow for fluid communication between the central and peripheral areas of die redistribution tray. In the embodiment of Figure 2A, elements of the apparatus corresponding to the elements in other illustrated embodiments are designated by die same reference numbers. The construction and function of various elements of the embodiment of Figure 2A will be apparent to those skilled in the art from the discussion of die remaining embodiments. As will be discussed in more detail below, where two sets of beams are provided, an opening 76 is provided in d e second set of radial beams to allow passage of the quench fluid manifold. Where only a single beam is provided, an opening is provided in die upper portion of die beam to allow passage of the quench fluid manifold (see Figure 2C). In the preferred embodiment having a first and second ring, there is no obstruction for the quench fluid manifold. A liquid collection tray 78, preferably frusto-conical shaped, is formed by attaching solid plate tray sections to the top of the second set of radial beams. Of course, if feasible, a single plate may be fastened to die top of the second set of beams. Of course, where only a single beam is provided, die day 78 will be fastened to die top of tbe beam. Similarly, where a first and second ring are provided as in die preferred embodiment, die outer portion of die tray is fastened to d e second ring while die inner portion is fastened to the first ring. Since die tay will be sloped, it will form a cone with a trough against die wall of the swirl chamber. Reactants dropping on die liquid collection tray 78 from above flow toward die openings 32 in die wall of d e swirl chamber. In die central area of die reactor, reactants drop onto die ceiling 28 of d e swirl chamber and flow radially outward over de edge and into die trough. Reactants flow from the trough into the swirl chamber dirough die openings. The sloped liquid collection tray reduces the residence time for liquid on die tray. The reduced residence time consequently reduces die thermal cracking of the liquid, coking and die formation of precursors of polynuclear aromatics. Figure 2B illustrates a perspective view of a portion of the quench zone mixing apparatus showing a modified embodiment diereof. For example, in the embodiment of Figure 2B, d e size and shape of the openings 72 is somewhat different than in the other embodiments. It will be apparent to those skilled in d e an that, in the embodiment of Figure 2B, elements of the apparatus corresponding to die elements in other illustrated embodiments are designated by die same reference numbers. The construction and function of various elements of the embodiment of Figure 2B will be apparent to ose skilled in die art from die discussion of the remaining embodiments of the invention. Figures 2C and 2D illustrate a perspective view of a portion of the quench zone mixing apparatus showing yet another modified embodiment thereof. In this embodiment, a single set of radial beams 66A is used instead of die first set of radial beams 66 and die second set of radial beams 74 of the embodiment of Figure 2. In this embodiment, die radial beams 66A include a web 68A. It will be apparent to those skilled in the art that, in the embodiment of Figures 2C and 2D, elements of the apparatus corresponding to the elements in other illustrated embodiments are designated by die same reference numbers. The construction and function of various elements of the embodiment of Figures 2C and 2D will be apparent to those skilled in the art from the discussion of die remaining embodiments of die invention. As best seen in FIG. 3, inside the swirl chamber, baffles 40 are provided at each opening to cause the incoming flow to turn 90 degrees or tangent to the swirl chamber wall so diat die fluid flows circumferentially downward. The baffles are spaced apart a distance so diat die fluid exiting one baffle does not bit the adjacent baffle. Each baffle includes a downwardly angled tangential ramp 42 having an edge 44 attached to die wall of die swirl chamber adjacent die bottom 34 of the opening The tangential ramps do not extend to the floor of the swirl chamber and thus do not interfere widi die fluid flow from the previous ramp. Preferably, the ramp is substantially rectangular or square widi die edge 44 of one of its sides attached to die swirl chamber wall 30. The opposite or distal side 46 has an impinging wall 48 extending upward and joined to an end wall 50 diat extends substantially normal to the impinging wall and upward from the ramp. One edge 52 of die end wall may be attached to die swirl chamber wall. The impinging wall 48 can be either flat or curved parallel to the swirl chamber wall 30. The edge between the impinging wall 48 and the tangential ramp 42 is, in either case, sealed to prevent leakage. The top edges of die impinging wall 48 and die end wall 50 should fit flush against the swirl chamber ceiling to minimize leakage past the baffles. The baffles therefore define a circumferential opening 54. The circumferential opening of each baffle is in the same direction, e.g. , counter¬ clockwise in FIGs. 2 and 3, to cause the fluid to flow circumferentially, or swirl around die swirl chamber. The circumferential opening may, of course, be positioned in a clockwise direction, if desired. The swirling effect ensures good mixing with the otiier fluid streams from die otiier tangential ramps. The swirling fluid flows in a spiral manner toward die center of the swirl chamber as it is replaced by additional fluid flowing down die tangential ramps. At the center, the fluid spills over die weir to exit the swirl chamber. Sufficient pressure drop is taken across the opening and tangential ramp to provide die fluid widi enough velocity head to achieve a swirling effect in the fluid pool of reactants on the floor of die swirl chamber. In reactors where quench fluid is used to cool die reactants or makeup a disappearing reactant, a quench fluid system 80 (best seen in FIGs. 4A and 4B) may be provided to inject die quench fluid into the swirl chamber. The quench fluid may be from an external source or an internal source and is generally introduced through a quench feed pipe 82 diat passes through die vessel wall 11. The quench feed pipe 82 is connected to a concentric manifold 84 diat passes dirough die openings 76 in the second set of radial support beams (where two sets are provided) and encircles the swirl chamber 20. Quench laterals 86 communicate widi die manifold to transfer the quench fluid to the swirl chamber. The quench laterals 86 terminate widi nozzles 88 that extend inward dirough the swirl chamber wall under die tangential ramps. Preferably, the nozzles terminate at about die innermost portion of die baffle. The nozzles have an opening 90 to discharge die quench fluid into a corresponding incoming fluid stream flowing down die tangential ramps. The opening 90 is preferably oriented so that the quench fluid will be directed circumferentially into the vessel. The nozzles may have a horizontal slot or a number of spaced in-line orifices on the same side as die circumferential baffle opening to produce flow parallel to the reactants flowing down the ramps. Therefore, the quench fluid passes into the curtain of reactant fluid flowing off the end of die ramp to achieve intimate mixing and cooling of the reactant fluid. Introduction of die quench fluid into the side of die swirl chamber (rather than above) reduces die overall veπical height of the apparatus. Furthermore, allowance does not have to be made for the quench piping between the catalyst suppoπ beams and the top of die liquid collection tray. In addition, introduction of the quench fluid into the swirl chamber produces an efficient mixing of the fluids. The swirl chamber design dierefore achieves excellent mixing of fluids from all sections of die reactor to reach thermal equilibration. This eliminates hot zone propagation from one bed to the next. As noted above, d e swirl chamber has a floor 22 consisting of a solid plate that surrounds a central orifice 24. An overflow weir 26 about the periphery of the orifice extends above die orifice to define a basin on die floor inside die swirl chamber. At the center of die swirl chamber, the fluid overflows the weir and exits die swirl chamber. The fluid exiting the swirl chamber is directed downward to die rough distribution network 100 (best seen in FIGs. 4A, 5 A, 5B, and 5C) which collects the swirl chamber exit fluid and directs it radially outward and onto d e distribution apparatus 120. The rough distribution network includes a splash plate 102 and channels 108 in fluid communication widi die splash plate. The splash plate is located below the swirl chamber outlet weir and may be removably secured by a support 65 attached to die central hub 64 of die support structure. The splash plate has a few apertures 104 to allow some of die fluid to pass through and onto die redistribution plate 122. The splash plate also has shallow sides 106 except where it intersects widi the channels 108. At these intersections, de shallow sides preferably have openings connecting die splash plate with die channels to ease the fluid passage. Liquid accumulating on die splash plate will flow into die channels and out radially into die reactor. The channels 108 are in communication with die splash plate and extend radially outward toward die vessel wall. Preferably, the channels are attached to die webs 68 of die first set of radial support beams (where two sets are provided). The channels have shallow sides 110 diat provide a conduit for liquid to flow toward the reactor wall. The channels, however, may have any shape suitable for collecting the fluid and distributing it across die surface of die redistribution tray. For example, the channels may be substantially U-shaped, widi eidier a flat horizontal bottom or a rounded bottom, or may be V-shaped. At intervals along the channels, notches 112 are provided in die sides to produce die desired distribution of liquid onto the redistribution plate. Preferably, the shape and location of die notches provides a symmetrical dispersion of the fluid across die surface of the redistribution plate. Below the splash plate is the distribution apparams 120. The distribution apparatus may be fastened to the first set of radial beams (where two sets are provided) by for example, supporting it on die bottom flange of the first set of radial beams and fastening, if desired, by any suitable means to die bottom flange of the radial beams. As shown in FIGs. 6A and 6B, d e distribution apparatus includes a redistribution plate 122 with a plurality of apertures 124, a plurality of bubble caps 130, and a plurality of associated drip trays 150. Preferably, the redistribution plate fills substantially the entire cross section of die vessel and is oriented substantially horizontal to provide a substantially level area to collect die fluid from the rough distribution network. The apertures 124 in die plate are preferably symmetrically distributed to achieve a symmetrical distribution of fluid across the catalyst surface. FIGs. 6A and 6B show bubble caps associated widi die apertures of die redistribution plate. Preferably, an individual bubble cap is associated widi, e.g. , located above, an individual aperture to provide substantially die sole means for fluid to pass dirough die redistribution plate. In tiiis preferred embodiment, die redistribution plate is sealed to prevent the fluids from bypassing the bubble caps. Since die plate apertures are symmetrically distributed, the bubble caps are likewise symmetrically distributed. It is to be understood, however, diat many otiier arrangements may be suitable. Generally, one of die design considerations for die tray is that there be a sufficient number of bubble caps to ensure substantially uniform liquid distribution over tbe entire surface of die plate. The optimum number of bubble caps for any given purpose will depend upon many factors, die most obvious being the size of the reactor. Otiier contributing factors may be die liquid and gas flow rate to die reactor and die proportion of die ; eed remaining in the liquid phase. In general, the design of die redistribution plate will provide die proper number of bubble caps to assure acceptable liquid distribution and establish optimum liquid level on die upper surface of the tray and concomitant optimization of gas flow dirough each bubble cap for a given feed rate and reactor size. The bubble caps 130 include a riser 132 and a spaced apart cap 140 to form an inverted U-shaped flow path for the gas and liquid. The riser, which is generally cylindrical in form, has a lower lip 134 or extension that is received within an aperture in the plate 122, and a top 138. The riser may be cut from a lengtii of tubular material or may be rolled from a length of sheet stock as desired. The riser is secured to the redistribution plate by, for example, metal rolling or welding, or some other similar and suitable means. The riser has an inner passageway 136 between d e lower lip and tbe top diat provides a means of fluid communication across the redistribution plate. In die preferred embodiment where an individual bubble cap is associated widi an individual aperture, the inner passageway of the riser provides substantially die sole means of fluid communication across die redistribution plate. The cap 140 encompasses die top of die riser but is spaced from the riser to define a bubble cap annulus (or annular space). The cap comprises a top wall 142 terminating about its periphery in a downwardly extending skirt 144 that terminates above the upper surface of the redistribution plate and forms a gap between the skin and die upper surface of die redistribution plate. Preferably, the cap has a plurality of slots 146 in its lowermost outer periphery such as shown in U.S. Pat. No. 3,218,249, incorporated herein by reference. The slots allow the gas or vapor to flow into the annulus. The slots also provide a pressure drop such diat die liquid level in the annular space defined by die cap and die riser is higher than the liquid level on d e redistribution plate. The higher liquid level in die annular space will offset any irregularities in the liquid level on the redistribution plate and ensure a substantially uniform gas-liquid flow dirough each bubble cap, and substantially uniform mixing of die gas and liquid. At least one spacer 148 is located intermediate die riser and the cap to maintain die two in a spaced apart relationship widi one another. The spacer or spacers may also be arranged so diat die riser and the cap are maintained in a concentric relationship to each other. The spacer may be fastened to die riser, die cap, or both so that the top wall of the cap rests on the spacer. Preferably, the spacers extend radially outward to maintain the cap substantially centered with respect to the riser. The bubble cap design enables uniform liquid distribution even when die tray is not perfectly level or when there are differences in liquid depth across the tray. In addition, die liquid and gas phases are more intimately contacted compared to a chimney type distributor. This increases die level of diermal equilibration of die reactants. In operation, die liquid phase, substantially disengaged from die vapor (or gas) phase by gravity as it falls from the rough distribution network, fills up on the redistribution plate to a level below die slot depth in de bubble caps, widi die level being determined primarily by die gas flow rate per cap. It is, of course, necessary d at some of die slot openings be exposed above die liquid surface to permit die gas to pass dirough. The pressure drop dirough die redistribution tray in die reactor, which is normally quite small, forces die gas under die cap, eidier dirough the slots or under die cap. The gas entrains die liquid diat is present on the surface of die tray as it passes dirough die slots or under die cap. The fluid (gas and liquid) then flows upwardly dirough d e annulus between die cap and die riser, reverses direction and flows dirough d e passageway defined by die riser. The bottom of die riser extends through the aperture in the plate to provide a drip edge for liquid disengagement. Although bubble caps may satisfactorily distribute die fluid across die catalyst surface, d e present invention contemplates increasing the number of fluid drip streams exiting die redistribution plate to further enhance the symmetrical distribution of die fluid across the catalyst surface. Consequently, in a preferred embodiment, die present invention contemplates providing at least some horizontal drip trays 150 associated widi at least some bubble caps and located underneath the associated bubble caps. Preferably, an individual drip tray is associated widi and located directly underneath an individual bubble cap to collect die liquid from that cap and distribute it in a more finely divided and even more symmetrical pattern than can be achieved without die drip tray. The drip tray 150 is constructed widi a bottom 152 and a plurality cf side walls 154 extending upward from the bottom. The bottom has at least one discharge poπ 156 and, preferably has at least two discharge ports to effectively multiply the number of drip streams. As shown in FIG. 6B, the bottom of the drip tray has a plurality of discharge ports disposed relatively close to die corners to evenly discharge the liquid from the drip tray. It is to be recognized, however, that a variety of mediods or devices may be suitable to accomplish the objective of multiplying die number of drip streams. The drip tray is secured to die redistribution plate by, for example, welding. FIG. 6B shows mounting tabs 158 extending upward from die drip tray to be secured to die underside of die redistribution plate. Of course, any other suitable attachment mediods can be used. The drip tray is spaced from the bottom opening of the riser and is oriented in a horizontal manner. The horizontal positioning of the drip tray (or trays) peπnits the liquid traveling downward to accumulate within the drip tray and tiien be discharged from die tray in at least one, and preferably in more than one, stream through the discharge ports. Preferably, the drip tray is spaced a distance of about 1 to 2 inches from the redistribution plate. Referring now to FIG. 7, there is shown an alternative embodiment of a drip tray 200 having drip guides. The drip tray 200 is shown with the drip guides 202 placed at each corner 204 to protect and guide die discharged liquid falling from the discharge ports 206 formed in die bottom 207 of the drip tray. Another embodiment of die drip tray is shown in FIG. 8. In this embodiment, a drip tray 210 is constructed widi side walls 211 surrounding a bottom surface 212. A plurality of discharge ports 216 are positioned relatively close to die corners 218 of the drip tray. The bottom of the drip tray also has a number of indentations 220 to form a pattern of flow channels leading outwardly to die discharge ports and to further enhance die equal distribution of die liquid dirough die discharge ports. V-shaped notches 222 may be provided at die corners of die top of die side walls to accommodate overflow from the drip tray in the event of high liquid flow rates. In yet anodier alternative embodiment of die drip day, FIG. 9 shows a drip tray 230 having an x-shape. In this embodiment, the drip tray 230 is constructed with four arms 231 each having side wall portions 232 to define a controlled flow area. A discharge port 234 is provided at die end of each corner of the drip tray for the discharge of die collected liquid. While various alternative shapes of drip trays have been illustrated, one skilled in the art will appreciate that any shape suitable for collecting and distributing liquid dirough a multiplicity of discharge points may be used. One skilled in the art will also understand diat modifications may be made to the drip tray to achieve symmetry and flow balance as necessary to meet die desired performance parameters for a particular reaction vessel. The drip trays will dierefore more finely divide die liquid stream entering die catalyst bed below. It will be appreciated diat de bubble cap design described above provides substantially uniform liquid distribution even when die redistribution plate is not perfectly level or when there are differences in die depth of the liquid across the surface of die plate. In addition, die liquid and gas phases will be more intimately contacted, especially as compared to prior art chimney type distributors. Consequently, die level of diermal equilibration of die reactants, i.e. , die gas and liquid, is increased. While the present invention has been described widi reference to providing a unique quench zone mixing device diat includes a swirl chamber, a rough distribution network, and a distribution apparatus, die present invention also contemplates an improvement in known quench zone mixing devices. In particular, a rough distribution network is interposed between a mixing chamber and a distribution apparatus. The rough distribution network includes a splash plate in fluid communication widi outwardly extending channels. Preferably, the channels extend outward radially from the splash plate. The splash plate is located below die exit opening or openings of the mixing chamber and collects die fluid (e.g. , a liquid) from the mixing chamber. The splash plate may have shallow sides except where it intersects widi die channels. Fluid accumulating on die splash plate will flow into die channels and radially outward. The splash plate preferably has a few apertures and the channels preferably include side walls with spaced apart notches to allow fluid to exit the channels. Preferably, die shape and location of die notches provides a symmetrical dispersion of the fluid across the surface of the distribution apparatus. In addition, the present invention relates to the above-described distribution apparatus which is not associated with die quench zone mixing apparatus. For example, as shown in FIG. 1, die distribution apparatus 120 may be provided near die top of die reactor. In this embodiment, die distribution apparatus will collect fluid from above, evenly distribute it across die top surface of the redistribution plate, and further distribute die fluid downward to a down stream section of die reactor. While die distribution apparatus has been shown as being located near the top of die reactor, one skilled in die art will appreciate that die apparatus may be suitably located where needed in the reactor. The present invention also contemplates using the above-described embodiments of die quench zone mixing device in a process for contacting a fluid widi a gas. Preferably, die process occurs in a portion of a reactor between two successive spaced apart beds of particle form solids, e.g., catalyst particles. The process includes passing die fluid with a gas dirough the quench zone mixing device of tiiis invention, which is placed between die two successive beds. In another embodiment, die process includes introducing a fluid into a plurality of inlet openings provided on a swirl chamber. The swirl chamber includes a wall disposed between a ceiling and a floor which includes an orifice that provides a means of fluid communication out of the swirl chamber. The wail defines an inside of die swirl chamber. The fluid is mixed widi a quench fluid diat is also introduced into die swirl chamber to produce a swirl chamber fluid mixture. The swirl chamber fluid mixture is transported out of die swirl chamber and is collected on a rough distribution network disposed beneath d e swirl chamber. The rough distribution network includes a splash plate and outwardly extending channels, wherein die splash plate is adapted to collect die swirl chamber fluid mixture and radially distribute it dirough the channels and onto a distribution apparatus disposed beneadi die rough distribution network. The distribution apparams includes a redistribution plate having a plurality of apertures and a plurality of bubble caps widi at least some of die bubble caps associated widi at least some of die apertures and collects the swirl chamber fluid mixture. The collected swirl chamber fluid mixture is transported through die redistribution plate via the apertures and d e bubble caps. Preferably, a plurality of substantially horizontal drip trays are provided widi at least some of the drip trays located underneath die redistribution plate and associated widi at least some of the bubble caps, wherein die drip trays receive the fluid exiting the bubble caps and distribute it dirough at least one discharge poπ in die drip trays. If gas is present in the fluid, at least some separation of the gas from die fluid takes place in the bubble caps and on die drip trays. As noted tiiroughout, the embodiments described above provide a number of significant advantages. Importantly, the overall pressure drop across the device will be moderate while achieving excellent mixing and distribution of die gas and liquid. By providing a fluid (e.g., liquid) collection fray that is sloped, die residence time of die liquid on die tray is minimized which reduces diermal cracking of the liquid and in certain processes reduces coking and die foπnation of precursors of polynuclear aromatics. The presence of spaced apart inlet openings on the side wall of the swirl chamber reduces die overall vertical height of the quench zone mixing apparatus. In addition, by providing side inlet openings, the quench fluid can also be introduced into die side of die swirl chamber which also aids in minimizing die overall vertical height of the apparams. As a result, the height of die reactor vessel can be reduced, diereby reducing die capital cost of the reactor vessel. Where baffles are provided, die fluid is directed downwardly and circumferentially and can be intimately contacted by die quench fluid diat is introduced into the side of the swirl chamber to provide an efficient mixing and equilibration of die two fluids. Moreover, by creating a swirling flow of both, die fluids from die multiple inlet openings and the quench fluid, an intimate mixing of fluids from all sections of the vessel can be achieved diat will minimize hot zone propagation from one catalyst bed to the next. In the preferred embodiment where the baffles are attached to the inside of the swirl chamber, there will be no need to remove the baffles during maintenance Consequently, the swirl chamber can be easily maintained. As pointed out above, in a preferred embodiment the rough distribution network includes channels that are attached to the radial beams. The channels will not obstruct access to die redistribution tray from above and will, therefore, facilitate maintenance when cleaning of die redistribution tray is required. In addition, die number of individual pieces required is reduced which, in m, reduces the capital cost, assembly time and maintenance cost. By including the support structure as described above, the reactor design and fabrication will be simplified since multiple suppoπ rings or internal skirts will be dispensed with. Moreover, by dispensing widi an internal skirt, the entire interior surface of die reactor will be available for inspection. In die preferred embodiment, drip trays are used widi each bubble cap on die redistribution tray. The bubble caps provide good distribution of gas and liquid over the cross sectional surface below the redistribution tray. The drip trays improve the liquid distribution by multiplying die liquid distribution points. The drip trays can also extend under fixed internals such as beams or wall support rings to wet areas that could not be reached by die normal bubble cap or by a chimney type distribution device. It should be understood diat a wide range of changes and modifications can be made to the embodiments described above. It is dierefore intended that the foregoing description illustrates rather than limits this invention, and diat it is die following claims, including all equivalents, which define tiiis invention.

Claims: WHAT IS CLAIMED IS: 1. A quench zone mixing apparatus comprising: a. a swirl chamber that includes a wall disposed between a ceiling and a floor diat includes an orifice which provides a means of fluid communication out of die swirl chamber, the wall defining an inside of die swirl chamber, die swirl chamber further including a plurality of openings that provide a means of fluid communication into the swirl chamber; b. a rough distribution network disposed beneadi die swirl chamber that includes a splash plate and outwardly extending channels, wherein the splash plate is adapted to collect fluid exiting the orifice and radially distribute it dirough die channels; and c . a distribution apparatus disposed beneath the rough distribution network that includes a plate having a plurality of apertures and a plurality of bubble caps with at least some of the bubble caps associated with at least some of the apertures. 2. The quench zone mixing apparatus of claim 1 further comprising a plurality of baffles located inside die swirl chamber and in communication with die openings to receive and direct incoming fluid circumferentially about die swirl chamber. 3. The quench zone mixing apparatus of claim 2 wherein each baffle further includes: a. a bottom tangential ramp located adjacent a bottom of die opening and attached to die inside of die swirl chamber wall; b. an impinging wall extending upward from die distal end of die tangential ramp; and c. an end wall extending upward from the tangential ramp and normal to the impinging wall and die swirl chamber wall. 4. The quench zone mixing apparatus of claim 3 wherein the baffle includes a circumferential opening perpendicular to die inlet opening such that incoming fluid is directed tangentially to die swirl chamber wall. 5. The quench zone mixing apparatus of claim 3, wherein die impinging wall extends from die distal end of the tangential ramp to die ceiling. 6. The quench zone mixing apparatus of claim 4 wherein the circumferential opening is in the same direction for each baffle. 7. The quench zone mixing apparatus of claim 1 further comprising a weir formed about die periphery of the orifice to define a basin on the floor of the swirl chamber. 8. The quench zone mixing apparams of claim 1 further comprising a plurality of drip trays with at least some of the drip trays located underneath die plate and associated widi at least some of the bubble caps, wherein die drip trays receive the fluid exiting die bubble caps and distribute it dirough at least one discharge port in the drip trays. 9. The quench zone mixing apparatus of claim 8 wherein die drip tray further includes at least two discharge points. 10. The quench zone mixing apparatus of claim 1 further comprising a frusto- conical liquid collection tray surrounding die swirl chamber, wherein die liquid collection tray collects a fluid from a catalyst bed placed above die swirl chamber and directs it to the openings. 11. The quench zone mixing apparatus of claim 10 wherein die liquid collection tray has one end adjacent die swirl chamber wall and located adjacent de bottom of die openings and anodier end at a vertical height above die one end to define a downward sloping conical surface. 12. The quench zone mixing apparatus of claim 1 further comprising a quench fluid system that includes: a. a quench fluid feed pipe; b. a concentric quench fluid manifold surrounding the swirl chamber; and, c. a plurality of quench fluid laterals extending radially inward and terminating at nozzles that extend through the swirl chamber wall, each nozzle end having a discharge opening to direct quench fluid into die fluid stream falling from the baffles. 13. The quench zone mixing apparatus of claim 12 wherein an individual nozzle is associated with an individual baffle such that the quench fluid discharged from the nozzle is directed into the fluid stream falling from the associated baffle. 14. The quench zone mixing apparatus of claim 1 wherein the splash plate further includes a plurality of apertures. 15. The quench zone mixing apparatus of claim 1 wherein die channels include side walls with a plurality of spaced apart notches. 16. The quench zone mixing apparatus of claim 1 wherein an individual bubble cap is associated widi an individual aperture of die plate to provide die sole means of fluid communication through the plate and wherein an individual drip tray is horizontally secured in association widi an individual bubble cap. 17. The quench zone mixing apparams of claim 16 wherein d e bubble cap comprises: a. a riser having a lower end located within an aperture in die plate and a top end to define a passageway between the ends; b. a cap located over die top end of d e riser, die cap having a top portion and a downwardly extending skirt portion; and, c. a spacer located between die riser and the cap to maintain a gap between die top end of die riser and die cap. 18. The quench zone mixing apparatus of claim 17 wherein die caps have a plurality of spaced apart slots. 19. The quench zone mixing apparatus of claim 1 wherein die apparatus is located within a reactor vessel and further comprises a support structure that includes: a. a concentric hub; and, b. a first set of radial beams extending radially outward from die concentric hub to a single support ring attached to die reactor vessel, wherein the radial beams support the swirl chamber. 20. The quench zone mixing apparatus of claim 19 wherein the beams have a flange to support the distribution apparatus. 21. The quench zone mixing apparatus of claim 19 wherein the channels are provided on the beams. 22. The quench zone mixing apparams of claim 19 further comprising a second set of radial beams placed on top of the first set of radial beams. 23. The quench zone mixing apparatus of claim 1 wherein the apparatus is located within a reactor vessel and further comprises a support structure that includes: a. a concentric hub; and, b. a single set of radial beams extending radially outward from die concentric hub to a single supporting ring attached to die reactor vessel, wherein the radial beams support the swirl chamber. 24. A reactor comprising a quench zone mixing apparatus interposed between two catalyst beds, an upstream and a downstream catalyst bed, wherein die quench zone mixing apparams comprises: a. a swirl chamber that includes a wall disposed between a ceiling and a floor which includes an orifice that provides a means of fluid communication out of die swirl chamber, the wall defining an inside of die swirl chamber, die swirl chamber further including a plurality of openings diat provide a means of fluid communication into the swirl chamber; b. a rough disttibution network disposed beneath die swirl chamber, the network including a splash plate and radially outwardly extending channels, wherein the splash plate is adapted to collect fluid exiting die orifice and radially distribute it through the channels; and c. a distribution apparatus disposed beneath die rough distribution network, die distribution apparams including a plate having a plurality of apertures and a plurality of bubble caps with at least some of die bubble caps associated widi at least some of die apertures. 25. The reactor of claim 24 wherein the quench zone mixing apparatus further comprises a plurality of baffles located inside die swirl chamber and in communication widi die openings to receive and direct incoming fluid circumferentially about die swirl chamber. 26. The reactor of claim 25 wherein each baffle further includes: a. a bottom tangential ramp located adjacent a bottom of die inlet opening and attached to the inside of die swirl chamber wall; b. an impinging wall extending upward from die distal end of die tangential ramp; and c. an end wall extending upward from the tangential ramp and normal to the impinging wall and die swirl chamber wall. 27. The quench zone mixing apparams of claim 26 wherein the baffle includes a circumferential opening perpendicular to die inlet opening such diat incoming fluid is directed tangentially to die swirl chamber wall. 28. The quench zone mixing apparams of claim 26 wherein die impinging wall extends from the distal end of the tangential ramp to the ceiling. 29. The reactor of claim 27 wherein die circumferential opening is in the same direction for each baffle. 30. The reactor of claim 24 wherein the quench zone mixing apparams further comprises a weir formed about the periphery of the orifice to define a basin on the floor of the swirl chamber. 31. The reactor of claim 24 wherein die quench zone mixing apparatus comprises a frusto-conical liquid collection tray surrounding die swirl chamber, wherein me liquid collection tray collects a fluid exiting from above the upstream catalyst bed and directs it to die openings. 32. The reactor of claim 31 wherein the liquid collection tray has one end adjacent the swirl chamber wall and located adjacent die bottom of d e openings and anodier end at a vertical height above the one end to define a downward sloping conical surface. 33. The reactor of claim 24 wherein die quench zone mixing apparatus further comprises a quench fluid system diat includes: a. a quench fluid feed pipe; b. a concentric quench fluid manifold surrounding die swirl chamber; and, c. a plurality of quench fluid laterals extending radially inward and terminating at nozzles diat extend dirough die swirl chamber wall, each nozzle end having a discharge opening to direct quench fluid into die fluid stream falling from the baffles. 34. The reactor of claim 33 wherein an individual nozzle is associated widi an individual baffle such diat die quench fluid discharged from the nozzle is directed into the fluid stream falling from the associated baffle. 35. The reactor of claim 24 wherein die splash plate further includes a plurality of apertures. 36. The reactor of claim 24 wherein die channels include side walls with a plurality of spaced apart notches. 37. The reactor of claim 24 wherein the plate is substantially horizontally mounted within the vessel below die swirl chamber, the plate extending across the cross-section of die vessel to separate an upper section of the vessel from a lower section. 38. The reactor of claim 24 further comprising a plurality of substantially horizontal drip trays with at least some of the drip trays located underneath die plate and associated widi at least some of the bubble caps, wherein die drip trays receive fluid exiting die bubble caps and distribute it through at least one discharge port in the drip trays. 39. The reactor of claim 38 wherein die drip tray further includes at least two discharge ports. 40. The reactor of claim 24 wherein an individual bubble cap is associated with an individual aperture of die plate to provide die sole means of fluid communication through die plate and wherein an individual drip tray is horizontally secured in association with an individual bubble cap. 41. The reactor of claim 40 wherein die bubble cap comprises: a. a riser having a lower end located within an aperture in the plate and a top end to define a passageway between die ends; b. a cap located over the top end of die riser, die cap having a top poπion and a downwardly extending skirt portion; and, c. a spacer located between die riser and die cap to maintain a gap between die top end of die riser and die cap. 42. The quench zone mixing apparatus of claim 41 wherein die caps have a plurality of spaced apart slots. 43. The reactor of claim 24 further comprising a support structure that includes: a. a concentric hub; and. b. a first set of radial beams extending radially outward from die hub to a single support ring attached to the reactor vessel, wherein the radial beams support the swirl chamber. 44. In a reactor comprising a quench zone mixing apparams including a quench zone mixing chamber disposed above a distribution apparatus, the improvement comprising interposing a rough disttibution network between the quench zone mixing chamber and die distribution apparams, die rough distribution network including a splash plate in fluid communication widi outwardly extending channels. 45. The reactor of claim 44 wherein the channels further include side walls with a plurality of spaced apart notches. 46. The reactor of claim 44 wherein die splash plate further includes a plurality of apertures. 47. In a quench zone mixing apparatus including a quench zone mixing chamber disposed above a distribution apparatus, die improvement comprising interposing a rough distribution network between die quench zone mixing chamber and the distribution apparams, the rough distribution network including a splash plate in fluid communication widi outwardly extending channels. 48. The quench zone mixing apparams of claim 47, wherein the channels further include side walls with a plurality of spaced apart notches. 49. The quench zone mixing apparams of claim 47, wherein die splash plate further includes a plurality of apertures. 50. A distribution apparatus comprising: a. a plate with a plurality of apertures; b. a plurality of bubble caps widi at least some of die bubble caps associated widi at least some of the apertures. 51. The distribution apparams of claim 50 wherein an individual bubble cap is associated widi each aperture. 52. The distribution apparams of claim 50 further comprising a plurality of drip trays with at least some of die drip trays located underneath the plate and associated witii at least some of die bubble caps, wherein die drip trays receive fluid exiting the bubble caps and distribute it through at least one discharge poπ in the drip trays. 53. The distribution apparams of claim 52 wherein die drip tray further includes at least two discharge points. 54. The distribution apparams of claim 50 wherein an individual bubble cap is associated widi an individual aperture of the plate to provide die sole means of fluid communication through the plate and wherein an individual drip tray is horizontally secured in association with an individual bubble cap. 55. The distribution apparams of claim 54 wherein die bubble cap comprises: a. a riser having a lower end located within an aperture in the plate and a top end to define a passageway between die ends; b. a cap located over die top end of die riser, the cap having a top portion and a downwardly extending skin portion; and, c. a spacer located between the riser and die cap to maintain a gap between die top end of die riser and die cap. 56. The distribution apparatus of claim 55 wherein die caps have a plurality of spaced apart slots. 57. A reactor having at least one catalyst bed and a distribution apparatus located above the catalyst bed, wherein die distribution apparams comprises: a. a plate with a plurality of apertures; b. a plurality of bubble caps widi at least some of the bubble caps associated with at least some of die apertures. 58. The reactor of claim 57 wherein an individual bubble cap is associated with each aperture. 59. The reactor of claim 57 further comprising a plurality of drip trays with at least some of die drip trays located underneath the plate and associated with at least some of the bubble caps, wherein die drip trays receive fluid exiting die bubble caps and distribute it dirough at least one discharge port in the drip trays. 60. The reactor of claim 59 wherein at least some of the drip trays further include at least two discharge points. 61. The distribution apparatus of claim 57 wherein an individual bubble cap is associated with an individual aperture of the plate to provide the sole means of fluid communication through the plate and wherein an individual drip tray is horizontally secured in association with an individual bubble cap. 62. The distribution apparatus of claim 61 wherein die bubble cap comprises: a. a riser having a lower end located within an aperture in the plate and a top end to define a passageway between die ends; b. a cap located over die top end of die riser, the cap having a top portion and a downwardly extending skin portion; and, c. a spacer located between die riser and die cap to maintain a gap between the top end of the riser and the cap. 63. The distribution apparatus of claim 62 wherein the caps have a plurality of spaced apart slots. 64. A process for contacting fluid reactants in a reactor comprising the steps: a. introducing a first fluid into die reactor at a location above a swirl chamber; b. introducing the first fluid into die swirl chamber; c. introducing a second fluid into die swirl chamber and contacting the first fluid widi die second fluid to foπn a swirl chamber fluid mixture; d. collecting die swirl chamber fluid mixture exiting from an outlet in the swirl chamber; e. distributing the swirl chamber fluid mixture through a rough distribution network which includes a splash plate and outwardly extending channels; f. passing a fluid mixture exiting the outwardly extending channels onto a distribution apparams that includes a redistribution plate with a plurality of apertures and a plurality of bubble caps widi at least some of die bubble caps associated widi at least some of die apertures; and g. transporting the fluid mixture through die redistribution plate to form a redistribution tray fluid mixture. 65. The process of claim 64 further comprising die steps of: a. collecting die redistribution tray fluid mixture on a plurality of substantially horizontal drip trays with at least some of the drip trays located underneath die redistribution plate and associated widi at least some of the bubble caps; and, b. distributing die collected redistribution tray fluid mixture through at least one discharge port in die drip trays. 66. A process for transferring a fluid from a first bed of a reactor to a second bed of a reactor comprising the steps: a. introducing a fluid from the first bed of die reactor into a swirl chamber; b. removing the fluid from die swirl chamber and introducing it into a rough distribution network including a splash plate and outwardly extending channels; and c . radially distributing die fluid over a distribution apparatus that includes a redistribution plate with a plurality of apertures and a plurality of bubble caps widi at least some of the bubble caps associated widi at least some of die apertures; and d. transporting the fluid dirough the redistribution plate to the second bed of the reactor. 67. The process of claim 66 further comprising the steps of: a. introducing a second fluid into the swirl chamber; and, b. contacting die first fluid widi the second fluid to form a swirl chamber fluid mixture. 68. The process of claim 68 further comprising die steps of: a. collecting die fluid transported dirough die redistribution plate on a plurality of substantially horizontal drip trays with at least some of the drip trays located underneath die redistribution plate and associated wid at least some of the bubble caps; and, b. distributing the fluid through at least one discharge poπ in the drip trays.

Inventors: BINGHAM F EMMETT, KUSKIE ROBERT W, NELSON DOUGLAS E, BINGHAM, F., EMMETT, KUSKIE, ROBERT, W., NELSON, DOUGLAS, E.
Applicants: BINGHAM F EMMETT, FLUOR CORP, KUSKIE ROBERT W, NELSON DOUGLAS E, BINGHAM, F., EMMETT, FLUOR CORPORATION, KUSKIE, ROBERT, W., NELSON, DOUGLAS, E.
Application year: 1997
Main classification: B01D47
IPC codes: B01D3, B01D47, B01F5, B01J8