STEAM-LIQUID CONTACT FLOOR WITH CANS AND TURNERS IN THE CANS AND PROCESS

Abstract

A contact floor is equipped with a base deck and partitions that isolate an upstream side of one or more cans on the floor from a downstream side of the cans. A tunnel extends from the base deck to the upstream side of each can to direct liquid from the base deck to a lower vortex generator, which may be positioned inside the can below a level of the base deck. The lower vortex generator imparts a centrifugal vortex motion to the vapor rising in each can, causing the liquid and vapor to mix within the can. Outlet openings are provided on the downstream side of the cans to allow the liquid to exit after mixing with the vapor. The vapor then exits from the open top of each can.

Description

RELATED APPLICATIONSThis application claims the benefit of U.S. Provisional Patent Application No. 63 / 449,191, filed Mar. 1, 2023, which is hereby incorporated by reference in its entirety.BACKGROUNDThe present disclosure relates to chemical processing columns in which mass transfer and / or heat exchange occurs between fluid streams and specific vapor-liquid contact trays used in such columns to facilitate contact between the fluid streams flowing in the column, and methods for contacting the fluid streams using the contact trays.Contact flow trays are used in mass transfer and heat exchange columns to facilitate contact between fluid streams flowing countercurrently in the column. As used herein, the term "mass transfer column" is intended to refer to columns in which mass transfer, heat exchange, or mass transfer and heat exchange are to take place. The fluid streams are typically an ascending vapor stream and a descending liquid stream. In this case, the contact trays are usually referred to as vapor-liquid contact trays. In some applications, both fluid streams are liquid streams and the contact trays are commonly referred to as liquid-liquid contact trays. In still other applications, the ascending fluid stream is a gas stream and the descending fluid stream is a liquid stream. In this case, the contact trays are referred to as gas-liquid contact trays.The contact trays each have a planar tray deck on and above which the interaction between the ascending fluid stream and the descending fluid stream occurs, a plurality of openings which allow the ascending fluid stream to pass upward through the tray deck and into the descending fluid stream to produce a foam or mixture in which the desired mass transfer and / or heat exchange occurs, and at least one downcomer which directs the descending fluid stream from the associated tray deck to a tray deck on an underlying contact tray. The contact trays are arranged vertically spaced apart in the mass transfer column, each tray deck extending horizontally and filling the entire internal cross section of the mass transfer column.One type of vapor-liquid contact tray designed for high fluid flow capacity and high efficiency applications uses a plurality of upstanding cylindrical cans on the tray deck to improve the mixing of the vapor and liquid streams. The cans extend upwardly from the bottom plate and surround the vapor openings formed in the bottom plate. Within each cylindrical can are swirl vanes which impart a swirling motion to the vapor rising within the can. In one embodiment, a downcomer passes liquid from an overlying tray into the center of each can where it is captured by the swirling vapor and causes a violent vapor-liquid interaction which results in high separation performance and subsequent separation of the liquid phase from the vapor phase. In another embodiment, the liquid flowing along the bottom deck enters each can through one or more openings in the outer peripheral wall forming the can.The centrifugal force that the swirling vapor in the can exerts on the liquid causes the liquid to splash against and rise along the inner wall surface of the can. Openings in the inner wall surface allow the liquid to flow through the inner wall surface and then sink to the floor deck. The liquid flows along the bottom deck and enters an opening in the bottom deck which forms an inlet to a downcomer which directs the liquid into a can on an underlying contact tray or onto the bottom deck of the underlying contact tray. The swirling vapor leaves the can through an open top of the can and then rises into and through an opening surrounded by a can in the bottom deck of an overlying contact tray. In this way, the vapor stream rises and the liquid stream drains from can to can in successive contact trays.BRIEF DESCRIPTIONThis summary is provided to introduce a selection of concepts in a simplified form that are further discussed in the following detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Other aspects and advantages of the present disclosure will become apparent from the following detailed description of the embodiments and the accompanying drawings.In one aspect, the present disclosure relates to a contact tray for allowing contact between ascending and descending fluids within a mass transfer column. The contact tray comprises: a tray deck; two or more cans positioned on and extending upwardly from the tray deck, each of the cans having a generally open top and being formed by an outer peripheral wall having a preselected height from a lower end to an upper end, the outer peripheral wall having a plurality of outlet openings extending through the wall to allow fluid to exit the interior of the can through the wall; openings extending through the tray deck within the areas defined by the individual cans to allow the fluid to flow upwardly through the tray deck within the cans; a lower swirler positioned to cause centrifugal swirling of the fluid as it flows upwardly in the cans; a downcomer extending downwardly from the bottom deck and comprising a downcomer inlet formed by an inlet opening in the bottom deck outside the areas defined by the cans for removing liquid from the bottom deck and conveying it downwardly, and a lower effluent outlet for draining the fluid from the downcomer; an inlet area on the bottom deck outside the areas defined by the cans for receiving liquid when drained from above onto the bottom deck; at least one tunnel constructed to provide a passage for directing liquid from the bottom deck to the lower swirler, the tunnel having a tunnel inlet positioned at an opening in the outer circumferential wall of the can above the bottom deck for allowing liquid on the bottom deck to enter the tunnel and a drain outlet positioned to direct descending liquid from the tunnel onto or adjacent the lower swirler for interacting with the centrifugally swirling fluid; and one or more baffles extending upwardly from the bottom deck and positioned to direct the liquid, when received in the inlet region of the bottom deck, to the tunnel inlets of the cans and then from the cans to the downpipe inlet of the downpipe.In another aspect, the present disclosure relates to a mass transfer column comprising: an upstanding outer shell defining an open interior region; and a plurality of the above-described horizontally extending contact trays positioned in vertically spaced relationship within the open interior region.In another aspect, the present disclosure relates to a method of operating a mass transfer column having an upstanding outer shell defining an open interior and a plurality of horizontally extending contact trays disposed vertically within the open interior. Each contact tray includes a tray deck, a plurality of cans extending upwardly from the tray deck, a downcomer extending downwardly from the tray deck and having a downcomer inlet at that tray deck, and partitions extending upwardly from the tray deck and separating an upstream front of each can from a downstream rear of each can to prevent fluid on the tray deck from flowing from the front to the rear around each can. The method comprises the steps of: supplying a first fluid downwardly through the downcomer extending downwardly from one of the contact trays and discharging the first fluid from the downcomer into an inlet region on a bottom deck of an underlying contact tray; directing the first fluid from the inlet region along the bottom deck and into the cans through a tunnel having a tunnel inlet positioned at an opening in an outer peripheral wall of each of the cans above the bottom deck; directing the first fluid downwardly in the tunnel and discharging from the tunnel on or adjacent the lower swirlers; Interaction of the first fluid exiting the tunnel with a second fluid rising through the bottom deck and the lower swirler in the cans on the underlying contact bottom by a swirling motion; draining the first fluid from the interior of the cans after interaction with the second fluid; and directing the drained first fluid from the one or more cans and delivering it to the downcomer inlet.BRIEF DESCRIPTION OF THE DRAWINGSThe present disclosure will be described in detail below with reference to the accompanying drawing figures, wherein: FIG. 1 is a perspective view of a mass transfer column with a portion of the outer shell of the mass transfer column broken away to illustrate a first embodiment of contact trays of the present disclosure positioned in an open interior region of the mass transfer column with two upright cans positioned on a tray deck of each contact tray; FIG. 2 is a fragmentary side view of the mass transfer column in vertical section through the mass transfer column and through the upstanding cans positioned on the tray tops of the contact trays; FIG. 3 is a perspective view of the first embodiment; FIG. 4 is a perspective view of the two contact bases shown in FIG. 3, but viewed from an opposite side; FIG. 5 is a top perspective view of the front or upstream side of one of the upstanding cans; FIG. 6 is a top perspective view of the upright can shown in FIG. 5, but with portions of an outer peripheral wall of the upright can broken away to show internal details; FIG. 7 is a bottom perspective view of the upstream side of the upstanding can shown in FIGS. 5 and 6; FIG. 8 is a plan view of one of the contact bases; FIG. 9 is a top view of a second embodiment of a contact pad of the present disclosure; FIG. 10 is a top view of a third embodiment of a contact tray of the present disclosure, which is in the form of a single stage cross-flow tray; FIG. 11 is a top view of a fourth embodiment of a contact tray of the present disclosure, which is in the form of a center-to-side double-start cross-flow tray; and FIG. 12 is a top view of a fifth embodiment of a contact tray of the present disclosure in the form of a two-pass, lateral center cross-flow tray to be used in alternating vertical relationship with the two-pass, lateral center cross-flow tray in FIG. 11.DETAILED DESCRIPTIONThe subject matter of the present disclosure is specifically described herein as complying with legal requirements. However, the description itself is not intended to limit the scope of this patent. Rather, the inventors have contemplated that the claimed subject matter could be embodied in other ways to include various components, combinations of components, steps, or combinations of steps similar to those described herein in connection with other current or future technologies.Referring now to the drawings in detail and initially to FIG. 1, a mass transfer column suitable for use in processes in which mass transfer and / or heat exchange is to take place between countercurrent flowing fluid streams is generally designated by the numeral 10. Mass transfer column 10 includes an upstanding outer shell 12 having a generally cylindrical configuration, although other configurations, including polygonal ones, are also possible and are within the scope of the present invention. Shell 12 has any suitable diameter and height and is made of one or more rigid materials which are preferably inert to, or otherwise compatible with, the fluids and conditions present during operation of mass transfer column 10.Mass transfer column 10 is of a type used for processing fluid streams, typically liquid and vapor streams, to obtain fractionation products and / or otherwise effect mass transfer and / or heat exchange between the fluid streams. For example, the mass transfer column 10 may be a column in which petroleum atmospheric fractionation, lubricating oil vacuum fractionation, petroleum vacuum fractionation, fluid or thermal cracking fractionation, coker or visbreaker fractionation, coke scrubbing, reactor exhaust gas scrubbing, gas quenching, edible oil deodorizing, pollutant scrubbing, and other processes proceed. The mass transfer column 10 can be set up on land or offshore, for example on a floating platform, a cargo port or a ship.Shell 12 of mass transfer column 10 defines an open interior region 14 in which the desired mass transfer and / or heat exchange between the fluid streams occurs. Normally, the fluid streams consist of one or more ascending vapor streams and one or more descending liquid streams. Alternatively, the fluid streams may comprise both ascending and descending liquid streams or an ascending gas stream and a descending liquid stream.The fluid streams are directed to mass transfer column 10 through any number of feed lines 16 positioned at appropriate locations along the height of mass transfer column 10. One or more vapor streams may also be generated within mass transfer column 10 rather than being introduced into mass transfer column 10 through feed lines 16. Mass transfer column 10 typically also includes an overhead line 18 for draining a vapor product or byproduct and a lower effluent line 20 for draining a liquid product or byproduct from mass transfer column 10.A plurality of horizontally extending contact trays 22 of a first embodiment are positioned in vertically spaced relationship within the open interior 14 of the mass transfer column 10. The contact floors 22 include a floor deck 24, which may be comprised of a number of individual panels joined together in various known ways. The bottom deck 24 should extend horizontally over the entire or substantially the entire internal cross section of the mass transfer column 10.With additional reference to FIGS. 2, 3, 4, 5, 6, 7-8, each of the contact bases 22 includes a plurality of upstanding cans 26 arranged in a preselected pattern and supported by the base deck 24. The upstanding cans 26 extend upwardly from the floor deck 24 a preselected distance and may also extend a lesser distance below the floor deck 24 in some embodiments. Each can 26 is formed by an outer peripheral wall 28 having a preselected height between a lower end 30 and an upper end 32. The outer peripheral wall 28 typically has a substantially cylindrical configuration, although polygonal and other configurations may also be used. Each outer peripheral wall 28 is suitably secured to the bottom plate 24 of the contact floor 22, such as by bolting, welding, or otherwise. In one embodiment, a flat circular ring 34 surrounds the outer peripheral wall 28 and is secured to the outer peripheral wall 28 and to the floor deck 24.The outer peripheral walls 28 may include a portion that extends below the floor deck 24. The height of the portion of each outer peripheral wall 28 of each can 26 above the floor deck 24 is less than the vertical distance between adjacent contact floors 22, such that the top end 32 of each outer peripheral wall 28 is a preselected distance below the overlying contact floor 22 to allow the ascending stream of vapor or liquid to exit through the open or substantially open top 36 of each can 26.Typically, the height of each outer peripheral wall 28 above the floor deck 24 is at least half, or more preferably at least two-thirds, of the vertical distance between adjacent contact floors 22. The height of the outer circumferential walls 28 of the cans 26 on one contact floor 22 may be the same as or different from the height of the outer circumferential walls 28 of the cans 26 on other contact floors 22. In one embodiment, the cans 26 on each contact tray 22 are vertically aligned with the cans 26 on vertically adjacent contact trays 22. In another embodiment, the cans on each contact tray 22 are not vertically aligned with the cans 26 on vertically adjacent contact trays 22.The contact trays 22 also include openings 38 formed in the tray deck 24 to allow the ascending vapor or other fluid stream to flow upwardly through the tray deck 24. In one embodiment, all or substantially all of the apertures 38 are positioned within the area enclosed by the outer circumferential walls 28 of the cans 26 such that all or substantially all of the vapor or other fluid stream flowing upwardly through the bottom deck 24 rises through the cans 26. A single large opening 38 may be enclosed by the outer peripheral wall 28 of each can 26, or multiple smaller openings 38 may be enclosed by the outer peripheral wall 28 of each can 26. The number and diameter of the cans 26 and the size of the apertures 38 are selected to provide the desired flow capacity for vapor or other fluid streams and the desired volume for the intended vapor-liquid or other fluid-fluid interaction in the portion of the mass transfer column 10 in which the contact trays 22 are positioned.A lower swirler 40 is positioned in each can 26 at a location at or below the height of the bottom deck 24 so that vapor or other fluids rising into the lower end 30 of each can 26 must flow through the lower swirler 40 as they rise in the can 26. The lower swirler 40 imparts a centrifugal swirling motion to the ascending vapor or other fluid streams. In one embodiment, an upper swirler 42 is also provided in each can 26 and is positioned at a location spaced above the lower swirler 40 to effect additional centrifugal swirling of the ascending vapor or other fluid as well as the entrained liquid or other fluid as described below.Each of the lower swirlers 40 and upper swirlers 42 includes a plurality of radially extending vanes 44 that may be planar, curved, or other shaped. The vanes 44 in the lower swirlers 40 may have the same or different shape and / or angle as the vanes 44 in the upper swirlers 42. for example, the vanes 44 in the lower swirlers 40 may be curved to allow gradual transition of the ascending steam or other fluid stream from a vertical flow direction to a flow direction with substantially radial, tangential or rotating flow vector. Because the vanes 44 in the upper swirlers 42 are exposed to the ascending vapor or other fluid stream and the entrained liquid or other fluid flowing with the radial flow vector, the vanes 44 in the upper swirlers 42 may be planar or have a lesser curvature compared to the vanes 44 in the lower swirlers 40.The lower swirlers 40 and the upper swirlers 42 may be oriented such that the vapor or other fluid stream and entrained liquid in each can 26 on each floor deck 24 swirl in the same rotational direction. Alternatively, the direction of rotation of the vapor or other fluid stream in some cans 26 may be different than in other cans 26. for example, the rotation of the vapor or other fluid stream in each can 26 may be clockwise (viewed from above) on one floor deck 24 and counter-clockwise in each can 26 on an adjacent floor deck 24. As another example, the direction of rotation of the vapor or other fluid stream may be clockwise in some cans 26 on a bottom deck 24 and counter-clockwise in the other cans 26 on the same bottom deck 24.The cans 26 each include a plurality of outlet ports 46 in the outer circumferential walls 28 of the cans 26 to permit the liquid in the cans 26 to exit the cans 26 through the outlet ports 46 after interaction with the swirling vapor or other fluid stream in the cans 26. The outlet ports 46 may have various shapes, such as plain holes, directional fins extending into the cans 26 as shown in the drawings, and outwardly curved tabs (not shown) angled downwardly to deflect exiting liquid downwardly toward the bottom deck 24. Other embodiments of the outlet openings 46 are provided within the scope of the present invention and are within its scope. As will be explained in more detail below, the outlet ports 46 may also be positioned only on a downstream side of each can 26.A downwardly bent lip ring 48 may be positioned at the upper end 32 of the outer peripheral wall 28 in each can 26 to trap any portion of the liquid exiting along the upper end 32 of the outer peripheral wall 28 and redirect the trapped liquid out of the can 26 and downwardly toward the bottom deck 24. Lip ring 48 may include an inner segment 50 positioned within outer peripheral wall 28 of associated can 26, a curved upper segment 52 spaced slightly above the top edge of wall 28, and an outer segment 54 positioned outside outer peripheral wall 28 to direct the captured liquid downward toward bottom deck 24. The lip ring 48 may be integrally formed with the outer peripheral wall 28 or may be separately manufactured and suitably secured to the outer peripheral wall 28.As best seen in Figures 5 and 6, each can 26 includes at least one tunnel 56 that may be positioned on an upstream side of the can 26 and is constructed to provide a passage for passing liquid from the bottom deck 24 to the lower swirler 40 within the can 26, where it interacts with and is entrained by the swirling vapor or other fluid stream rising within the can 26. The tunnel 56 has a tunnel inlet 58 positioned at an opening in the outer peripheral wall 28 of the can 26 above the bottom deck 24 to allow liquid on the bottom deck 24 to enter the tunnel 56, and a drain outlet 60 positioned to drain descending liquid from the interior of the tunnel 56 to the lower swirler 40 or to an area adjacent the lower swirler 40.In one embodiment, the tunnel 56 includes a horizontal segment 62 extending radially inward from the tunnel inlet 58 and a vertical segment 64 extending downward from the horizontal segment 62 at a central position within the can 26. When multiple tunnels 56 are used in each can 26, such as the two tunnels 56 shown in the drawings, the tunnels 56 may have a common vertical segment 64, with their tunnel inlets 58 spaced apart a selected circumferential distance in the outer circumferential wall 28 of the can 26. A bottom edge of each tunnel inlet 58 may be at the same height as a top of the floor deck 24 so that liquid on the floor deck 24 may easily flow into the tunnel inlets 58. The tunnel inlet 58 may be positioned to be below the level of the upper swirler 42 within the can 26.Each tunnel 56 is formed by one or more outer walls 66 that form an enclosure that defines the tunnel 56 and shields the liquid flowing through the tunnel 56 from the swirling vapor or other fluid streams that rise within the can 26. Because the tunnel 56 is in the flow path of the swirling steam or other fluid stream, the outer wall 66 in the horizontal portion 62 facing the swirling steam or other fluid stream may be inclined in the swirling direction to reduce its influence on swirling motion. In one embodiment, the outer walls 66 of the horizontal portion 62 of the tunnel 56 may form a parallelogram in cross-section that is inclined in the direction of centrifugal swirling, as shown in the drawing figures.The outflow outlet 60 of each tunnel 56 may be in the form of directional vanes 68 arranged to impart a directional flow to the liquid in the direction of centrifugal swirling as the liquid is conveyed from the outlet 60 onto or over the lower swirler 40. The directional vanes 68 may be disposed in the vertical portion 64 of the tunnel 56, with a lower end of the vertical portion 64 closed to allow all liquid flowing out of the tunnel 56 to exit through the directional vanes 68.Each contact tray 22 also includes one or more downcomers 70 that direct liquid from the contact tray 22 to an underlying contact tray 22, typically the adjacent underlying contact tray 22, The downcomer 70 may have various shapes and extends generally downward from a downcomer inlet 72 positioned at an inlet opening 74 on the tray deck 24 of the contact tray 22 to an outlet 76 positioned above an inlet region 78 on the underlying contact tray 24. The inlet area 78 on the underlying contact tray 24 may be horizontally offset from the downcomer inlet 72 on the overlying contact tray 24. The inlet portion 78 is positioned on the bottom deck 24 outside the cans 26.In the first embodiment of the contact trays 22 illustrated in Figures 1-3 and 8 wherein two cans 26 are positioned on each tray deck 24, the downcomer 70 may be generally tubular in shape having a curved portion 80 positioned between the vertically extending upper and lower portions 82 and 84, respectively.In the second embodiment of the contact trays 22 illustrated in Figure 9, in which six cans 26 are positioned on each tray deck 24, the downcomer 70 has the same tubular shape as in the first embodiment of the contact trays illustrated in Figures 1-3 and 8.In the third embodiment of the contact trays 22 illustrated in Figure 10, in which nine cans 26 are positioned on each tray deck 24, the downcomer 70 is a chord-shaped downcomer at one end of the tray deck 24, with the inlet region 78 at the opposite end of the tray deck 24 in a single pass crossflow tray arrangement.In the fourth embodiment of the contact trays 22 illustrated in Figure 11 in which forty-six cans 26 are positioned on each tray deck 24, two of the downcomers 70 are positioned at opposite ends of the tray deck 24, with the inlet region 78 being positioned centrally between the two downcomers 70 in a two pass center-to-side cross-flow tray arrangement. In the fifth embodiment of the contact trays 22 illustrated in Figure 12, in which 46 cans 26 are also positioned on each tray deck 24, the downcomer 70 is positioned centrally on the tray deck 24, and two inlet regions 78 are positioned at opposite ends of the tray deck in a two-pass side-to-center crossflow tray arrangement to be used in alternating vertical relationship with the two-pass center-to-side crossflow tray illustrated in Figure 11. It should be understood that other numbers, arrangements, and types of cans 26, downcomers 70, and inlet region 78 may be used and are within the scope of the present invention.An outlet weir (not shown) may be disposed adjacent each downcomer inlet 72 to collect the liquid stream on the bottom deck 24 to a preselected level before passing over the outlet weir and entering the downcomer 52. Similarly, adjacent each inlet region 78 on the bottom deck 24, an inlet weir (not shown) may be disposed to cause liquid to accumulate on the inlet region 78 to a preselected level before passing over the inlet weir and flowing along the bottom deck 24 towards the downcomer inlet 72 on the bottom deck 24.One or more baffles 86 extend upwardly from the bottom deck 24 on each contact tray 22 and are positioned to direct the liquid, when received in the inlet region 78 of the bottom deck 24, to the cans 26 where it interacts within the cans 26 with the vapor or other fluid streams that have passed upwardly through the openings 38 in the bottom plate 26 and then from the cans 26 to the downcomer inlet 72 of the downcomer 70 to supply it to the underlying contact tray 22. The baffles 86 are arranged and high to block or substantially prevent flow of liquid from the inlet portion 78 of the bottom deck 24 to the downcomer 72 on the bottom deck 26 without first flowing through at least one of the cans 26 on the bottom deck 26. The baffles 86 that contact the cans 26 are arranged to isolate a front or upstream side 88 of each can 26 containing the one or more tunnel inlets 58 from a rear or downstream side 90 of each can 26 containing the outlet openings 46 in the outer circumferential wall 28, and thereby force the liquid into the one or more tunnels 56 and prevent the liquid from flowing around the can 26 from the upstream side 88 to the downstream side 90.In the first embodiment of the contact tray 22 shown in Figures 1-3 and 8, one of the baffles 86 extends between the two cans 26, other baffles 86 extend from the cans 26 to the shell 12 of the mass transfer column 10, and another baffle 86 extends between the shell 12 and the baffle 86 extending between the two cans 26 to separate the downcomer 72 from the inlet region 78 on the tray deck 24. In this arrangement, the liquid passes successively through the two cans 26 on each floor deck 24.In the second embodiment of the contact tray 22 shown in Figure 9, the baffles 86 are arranged such that the liquid from the inlet portion 78 flows sequentially through each of the six containers 26 before entering the downcomer 70 through the downcomer inlet 72 on the tray deck 24.In the third embodiment of the contact tray 22 shown in FIG. 10, the baffles 86 form three zones or clusters each containing three cans 26. In this arrangement, the liquid flows from the inlet portion 78 through the cans 26 within each group of three cans 26 in parallel and then from one group of cans 26 to the next before entering the downcomer 70 through the downcomer inlet 72.Similarly, in the fourth and fifth embodiments of the contact tray 22 shown, the baffles 86 form a plurality of clusters each containing a plurality of cans 26, and the liquid flows from the inlet region(s) 78 in parallel through the cans 26 in each cluster of cans 26 and then from one cluster of cans 26 to the next before entering the downcomer(s) 70 through the downcomer inlet / inlets on each tray deck 24.The baffles 86 may be planar as shown in the drawings, or may be curved or have any other desired configuration. The baffles 86 extend beyond the bottom deck 24 and extend upwardly far enough to maintain the flow of liquid along the desired flow path through the cans 26. An upper edge of the partitions 86 should therefore normally overlie the uppermost outlet openings 46 formed in the outer peripheral walls 28 of the cans 26. The baffles 86 may extend upwardly a sufficient distance to bring the top edge of the baffles 86 into contact with the overlying floor deck 24 to provide additional support to the floor deck 24 and ensure an adequate spacing between adjacent floor decks 24. When the baffles 86 contact the overlying tray deck 24, vapor openings (not shown) may be provided near the top edge of the baffles 86 to allow the vapor stream to flow through the baffles 86 to equalize the pressure across the cross-section of the mass transfer column 10.During use of mass transfer column 10, a first fluid, which is normally a liquid stream, flows along tray deck 24 on contact tray 22 and is directed into downcomer inlet 72 and flows downwardly through downcomers 70 before exiting through outlet 76 to inlet region 78 of (adjacent) underlying contact tray 22. The first fluid then flows from the inlet region 78 along the floor deck 24 and into the cans 26 through the tunnel inlet 58 in the outer circumferential wall 28 of the cans 26. The discharged first fluid then interacts in the can 26 with a second fluid, which is typically a vapor stream that rises through the bottom deck 24 and the bottom swirler 40. The lower swirler 40 and the upper swirler 42 impart a centrifugal swirling motion to the second fluid and the exiting first fluid to effect thorough mixing of both. The centrifugal forces cause the first fluid to collide against an inner surface of the outer peripheral wall 28 where it rises until it encounters the outlet openings 46 in the outer peripheral wall 28. The first fluid is then removed from the inner surface of the outer peripheral wall 28 through the outlet openings 46 in the cans 26 after interacting with the second fluid discharged through the open top 36 of the can 26. The first fluid removed from the can 26 is directed to the bottom deck 24 and fed to the downcomer inlet 72 to repeat the above-described process on the next underlying contact tray 22.ADDITIONAL CONSIDERATIONSIn this specification, references to "a single embodiment," "an embodiment," or "embodiments" mean that the referenced feature or features are included in at least one embodiment of the technology. Separate references to "a single embodiment," "an embodiment," or "embodiments" in this specification do not necessarily refer to the same embodiment and do not exclude each other unless otherwise stated and / or readily apparent to those skilled in the art from the specification. For example, a feature, structure, action, etc. described in one embodiment may be included in other embodiments, but need not be. Thus, current technology may include a variety of combinations and / or integrations of the embodiments described herein.In the specification and claims, reference is made to several terms having the following meanings. The singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise.The approximation language used throughout the specification and claim herein may be used to modify any quantitative representation that could permissibly vary without changing the basic function to which it relates. Accordingly, a value modified by one or more terms such as "about" and "substantially" is not to be limited to the exact value indicated. At least in some cases, the approximation speech may correspond to the precision of an instrument for measuring the value. Range limits may be combined and / or interchanged. Such regions are marked and include all subareas included therein unless context or language provides otherwise.The term "axial" as used herein refers to directions and orientations substantially parallel to a central longitudinal axis of mass transfer column 10. The term "radial" refers to directions and orientations substantially perpendicular to the axis. The term "tangential" refers to directions and orientations tangential to the axis. The term "rotating" refers to directions and orientations in a rotational direction and orientation about the axis. Moreover, directional terms such as "page" and similar terms are used herein for clarity purposes only and should be understood only with respect to each other.The terms "coupled," "attached to," and the like refer to both direct coupling, attachment, or attachment, and indirect coupling, attachment, or attachment via one or more intermediary components or features, unless otherwise indicated herein.Although the present application contains a detailed description of various embodiments, it is to be understood that the legal scope of the description is defined by the wording of the claims and the corresponding language. The detailed description is intended to be exemplary only and does not describe every possible embodiment, as the description of every possible embodiment would be impractical. Numerous alternative embodiments may be implemented using current technology or technology developed after the filing date of this patent, which would still fall within the scope of the claims.In this specification, multiple instances may implement components, operations, or structures described as a single instance. Structures and functions represented as separate components in example configurations may be implemented as a combined structure or component. Likewise, structures and functions represented as a single component may be implemented as separate components. These and other variations, modifications, additions, and improvements fall within the scope of the subject matter treated herein. The statements above in this paragraph apply unless otherwise indicated in the description and / or are readily apparent to those skilled in the art from the description.As used herein, the terms "comprises," "comprising," "includes," "including," "has," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a process, method, article, or device comprising a list of elements is not necessarily limited to only those elements, but may also include other elements not expressly listed or inherent in such process, method, article, or device.Although the disclosure has been described with reference to the embodiments illustrated in the accompanying figures, it is to be understood that equivalents may be used and substitutions made herein without departing from the scope of the disclosure as set forth in the claims.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedUS 63 / 449, 191

[0001]

Claims

A contact tray for allowing contact between ascending and descending fluids within a mass transfer column, the contact tray comprising: a tray deck; two or more cans positioned on and extending upwardly from the tray deck, each of the cans having a generally open top and formed by an outer peripheral wall having a preselected height from a lower end to an upper end, the outer peripheral wall having a plurality of outlet openings extending through the wall for allowing fluid to exit the interior of the can outwardly through the wall; openings extending through the tray deck within the areas defined by the individual cans for allowing the fluid to flow upwardly through the tray deck within the cans; a lower swirler positioned to cause centrifugal swirling of the fluid as it flows up the cans; a downcomer extending down from the bottom deck and comprising a downcomer inlet formed by an inlet opening in the bottom deck outside the areas defined by the cans to remove and carry liquid down the bottom deck, and a lower effluent outlet for draining the fluid from the downcomer; an inlet area on the bottom deck outside the areas defined by the cans for receiving liquid as it is drained down onto the bottom deck; at least one tunnel constructed to provide a passage for directing liquid from the bottom deck to the lower swirler, the tunnel having a tunnel inlet positioned at an opening in the outer circumferential wall of the can above the bottom deck for allowing liquid on the bottom deck to enter the tunnel and a drain outlet positioned to direct descending liquid from the tunnel adjacent the lower swirler for interacting with the centrifugally swirling fluid; and one or more baffles extending upwardly from the bottom deck and positioned to direct the liquid, when received in the inlet area of the bottom deck, to the tunnel inlets of the cans and then from the cans to the downpipe inlet of the downpipe.The contact tray of claim 1, wherein the lower end of each can is positioned below the tray deck and the lower swirler in each can is positioned at least partially below the tray deck.The contact tray of claim 2 including an upper swirler positioned in each can above the at least one tunnel to effect additional centrifugal swirling of the liquid that has passed up through the tray deck and into the cans and the liquid that has been discharged from the lower outlet of the tunnel.The contact tray of claim 3, including directional vanes connected to the outlet of each tunnel, arranged to impart a directional flow to the liquid in the direction of centrifugal swirling as the liquid exits the effluent outlet.The contact floor of claim 4, wherein the tunnel includes an outer wall facing the centrifugal vortex and inclined in this direction.The contact tray of claim 5, wherein each of the cans has two or more tunnels extending radially inward from the outer peripheral wall of the can, and wherein the tray deck is generally planar.The contact tray of claim 1, wherein the tunnel inlets are positioned at an upstream front of each can and the plurality of outlet openings extending through the outer peripheral wall of each can are positioned at a downstream rear of each can, and wherein the baffles isolate the front of each can from the rear of each can to prevent the liquid on the tray deck from flowing from the front to the rear around each can and to cause the liquid to enter the tunnel inlets in each of the cans.The contact tray of claim 7, wherein the two or more cans comprise two or more arrays of multiple cans and the baffles isolate the front of each can from the back of each can in each can array to allow parallel flow of the liquid on the tray deck into each can in each can array and to prevent the liquid on the tray deck from flowing around the cans in each can array.A mass transfer column comprising: an upstanding outer shell defining an open interior region; and a plurality of horizontally extending contact trays according to claim 1 positioned in vertically spaced relation within the open interior region.The mass transfer column of claim 9, wherein the bottom end of each can is positioned below the bottom deck and the bottom swirler in each can is positioned at least partially below the bottom deck.The mass transfer column of claim 10 including an upper swirler disposed in each can above the at least one tunnel to effect additional centrifugal swirling of the fluid that has passed up through the bottom deck and into the can and the fluid that has been discharged from the lower outlet of the tunnel.The mass transfer column of claim 11 including directional fins connected to the outlet of each tunnel and arranged to impart a directional flow to the liquid in the direction of centrifugal agitation as the liquid exits the outlet.The mass transfer column of claim 12, wherein the tunnel includes an outer wall facing the centrifugal vortex and inclined in that direction.The mass transfer column of claim 13, wherein each of the cans has two or more tunnels extending radially inward from the outer circumferential wall of the can, and wherein the bottom deck is generally planar.The mass transfer column of claim 9, wherein the tunnel inlets are disposed at an upstream front of each can and the plurality of outlet ports extending through the outer circumferential wall of each can are disposed at a downstream rear of each can, and wherein the baffles isolate the front of each can from the rear of each can to prevent the liquid from flowing from the front to the rear on the bottom deck around each can and to cause the liquid to enter the tunnel inlets in each of the cans.The mass transfer column of claim 15, wherein the two or more cans comprise two or more multiple can arrays and the baffles isolate the front of each can from the back of each can in each can group to allow parallel flow of the liquid on the bottom deck into each can in each can group and to prevent the liquid on the bottom deck from flowing around the cans in each can group.A method of operating a mass transfer column having an upstanding outer shell defining an open interior region and a plurality of horizontally extending contact trays disposed vertically within the open interior region, each of the contact trays comprising a tray deck, a plurality of cans extending upwardly from the tray deck, a downcomer extending downwardly from the tray deck having a downcomer inlet at the tray deck, and baffles extending upwardly from the tray deck and isolating an upstream front of each can from a downstream rear of each can to prevent liquid on the tray deck from flowing around each can from front to rear, the method comprising the steps of: supplying a first fluid downwardly through the downcomer extending downwardly from one of the contact trays, and draining the first fluid from the downcomer to an inlet region on a bottom deck of an underlying contact tray; directing the first fluid from the inlet region along the bottom deck and into the cans through a tunnel having a tunnel inlet positioned at an opening in an outer peripheral wall of each of the cans above the bottom deck; directing the first fluid down the tunnel and draining from the tunnel onto or adjacent the lower swirlers; interacting the first fluid exiting the tunnel with a second fluid rising through the bottom deck and the lower swirler in the cans on the underlying contact tray by a swirling motion; draining the first fluid from the cans after interacting with the second fluid; and directing the discharged first fluid from the one or more cans and supplying to the downcomer inlet.The method of claim 17, wherein the first fluid is a liquid stream and the second fluid is a vapor stream.The method of claim 17, wherein the first fluid flows successively through the cans on each floor deck.The method of claim 17, wherein the first fluid flows in parallel through the cans on each floor deck.

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