Patent Publication Number: US-2022219248-A1

Title: Distillation tray having through holes with different diameters

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims the benefit of priority to U.S. Provisional Pant Application No. 62/844,040, filed May 6, 2019, the entire contents of which are hereby incorporated by reference it their entirety. 
    
    
     FIELD OF INVENTION 
     The present disclosure relates generally to one or more trays for use in a distillation column, and, but not by way of limitation, to trays without downcomers. 
     BACKGROUND 
     Distillation columns are used to separate liquid feed mixtures into component parts. Distillation columns typically include one or more trays, such as perforated trays, through which liquids flow down and vapors rise up during the separation process. These perforated trays include downcomers, which are conduits that are used to guide the flow of liquids from an upper tray to a lower tray and to allow vapor to pass from the lower tray to the upper tray. Although such trays can perform well in the distillation process, continued use can cause problems. For example, bottom sections of the trays may become fouled by rust and/or debris and, after cleaning, can become physically dislodged during use. Additionally, tray design for high liquid loading processes, such as C3 splitting, isomer separation, or deisobutaniser is challenging due to fouling of the trays often imposing a rate limitation on the distillation process. Typical multipass trays for such processes are structurally complicated and difficult to clean and inspect, resulting in long downtimes for cleaning. 
     SUMMARY 
     The present disclosure describes trays for use in distillation columns, and methods, devices, and systems for fabricating such trays. The trays include through holes (e.g., holes that extend between a first surface and a second surface of the trays) that have different diameters. Portions of the tray with through holes having one diameter are separated from portions of the tray having through holes with another diameter by a weir that extends from a surface of the tray. Some of the through holes have sufficiently small diameter such that these through holes may allow liquid to pass to lower trays while allowing vapor to pass upwards. Additionally, through holes with larger diameters may allow liquid to pass to lower trays without allowing vapor to pass upwards in an appreciable amount. In this manner, trays without downcomers may be formed that operate similar to conventional trays with downcomers. 
     To illustrate, a tray may include a first set of through holes in a first region of the tray and a second portion of through holes in a second region of the tray. The first set of through holes have a first diameter, and the second set of through holes have a second diameter that is different (e.g., larger) than the first diameter. A weir is positioned between the first region and the second region and extends from a surface of the tray. The weir is configured to prevent liquid from leaving one region until the liquid level rises above the height of the weir. For example, if liquid falls from an upper tray into the first region, the liquid does not spread to the second region until the level of the liquid is higher than the height of the weir. The tray of the present disclosure may perform similar to a conventional tray with downcomers by allowing liquid to pass to lower trays while allowing vapor to rise up to upper trays. For example, liquid may pass in one direction through the first set of through holes while vapor passes in an opposite direction. Additionally, liquid may pass in one direction through the second set of through holes (e.g., those with larger diameter), but the liquid may pass with higher volume and pressure such that vapor is substantially blocked. 
     In some implementations, the weir may extend linearly from one edge of the tray to an opposing edge. In other implementations, the weir may be a circular weir that surrounds the second set of through holes. Although two sets of through holes are described and one weir is described, such description is for illustration only. Trays of the present disclosure may have alternating regions of first through holes and second through holes separated by linear weirs, or alternating circular regions of first through holes and second through holes separated by concentric circular weirs. In still other implementations, hybrid designs that include some linear shaped regions (and weirs) and some circular shaped regions (and weirs) are possible. 
     The present disclosure also describes systems and methods of fabricating trays without downcomers. For example, a method may include forming a first set of through holes between two surfaces of the tray, followed by forming a second set of through holes between the two surfaces of the tray. The first set of through holes and the second set of through holes have different diameters. The method may also include attaching a weir to the tray between the first set of through holes and the second set of through holes. For example, a linearly extending weir or a circular weir may be attached to the tray to separate the first set of through holes from the second set of through holes. 
     Thus, the present disclosure describes perforated trays (e.g., trays with through holes) without downcomers, and methods, devices, and systems of fabricating the trays. Because of the selection of the diameter of the through holes, the trays are able to operate similar to trays with downcomers. Additionally, because there are no downcomers, the trays are less complex and less expensive to fabricate. Additionally, the lack of downcomers decreases the likelihood that the trays will be fouled by rust and/or debris, which increases the useful life of the trays and reduces downtime of distillation columns for cleaning. 
     In some of the foregoing embodiments, a method of manufacturing a tray for use in a distillation column comprises forming a first set of through holes extending between a first surface of a plate and a second surface of the plate. The second surface is opposite to the first surface. The first set of through holes each have substantially a first diameter. The method comprises forming a second set of through holes extending between the first surface and the second surface. The second set of through holes each have substantially a second diameter that is different than the first diameter. The method further comprises attaching a weir to the first surface between the first set of through holes and the second set of through holes. 
     In some such embodiments, forming the first set of through holes and the second set of through holes comprises punching the first set of through holes and the second set of through holes. Alternatively, forming the first set of through holes and the second set of through holes comprises drilling the first set of through holes and the second set of through holes. Alternatively, forming the first set of through holes and the second set of through holes comprises etching the first set of through holes and the second set of through holes. Additionally, or alternatively, the first set of through holes and the second set of through holes are formed at least partially concurrently. Alternatively, the second set of through holes are formed after formation of the first set of through holes. Additionally, or alternatively, attaching the weir to the first surface comprises bonding the weir to the first surface. In a particular embodiment, bonding the weir to the first surface comprises welding the weir to the first surface. Additionally, or alternatively, the method further comprises planarizing the first surface, the second surface, or both. Additionally, or alternatively, the second diameter is larger than the first diameter. 
     In some of the foregoing embodiments, a system for manufacturing a tray for use in a distillation column comprises first fabrication equipment configured to form a first set of through holes extending through a first surface of a plate and a second surface of the plate. The second surface is opposite to the first surface. The first set of through holes each have substantially a first diameter. The system comprises second fabrication equipment configured to form a second set of through holes extending through the first surface and the second surface. The second set of through holes each have substantially a second diameter that is different than the first diameter. The system also comprises third fabrication equipment configured to attach a weir to the first surface between the first and second set of through holes. 
     In some such embodiments, the first fabrication equipment comprises a tool having a plurality of extensions. The tool is configured to be pressed against the plate to form the first set of through holes, the second set of through holes, or both. Alternatively, the first fabrication equipment, the second fabrication equipment, or both include one or more drills. Alternatively, the first fabrication equipment, the second fabrication equipment, or both comprise an etching device. Additionally, or alternatively, the third fabrication equipment includes a device configured to bond the weir to the first surface. Additionally, or alternatively, the system further includes a planarizer configured to planarize the first surface, the second surface, or both. 
     In some of the foregoing embodiments, a non-transitory, computer readable medium stores instructions that, when executed by a processor, cause the processor to perform operations comprising initiating formation of a first set of through holes extending between a first surface of a plate and a second surface of the plate. The second surface may be opposite to the first surface. Each through hole of the first set of through holes may have substantially a first diameter. The operations also include initiating formation of a second set of through holes extending between the first and second surfaces. Each through hole of the second set of through holes each have substantially a second diameter different from the first diameter. The operations also comprise initiating attachment of a weir to the first surface between the first and second set of through holes. 
     In some such embodiments, the formation of the first set of through holes and the formation of the second set of through holes are initiated at least partially concurrently. Alternatively, the formation of the second set of through holes are initiated after formation of the first set of through holes. Additionally, or alternatively, the operations further comprise initiating planarization of the first surface, the second surface, or both. 
     As used herein, various terminology is for the purpose of describing particular implementations only and is not intended to be limiting of implementations. For example, as used herein, an ordinal term (e.g., “first,” “second,” “third,” etc.) used to modify an element, such as a structure, a component, an operation, etc., does not by itself indicate any priority or order of the element with respect to another element, but rather merely distinguishes the element from another element having a same name (but for use of the ordinal term). The term “coupled” is defined as connected, although not necessarily directly, and not necessarily mechanically; two items that are “coupled” may be unitary with each other. The terms “a” and “an” are defined as one or more unless this disclosure explicitly requires otherwise. 
     The term “about” as used herein can allow for a degree of variability in a value or range, for example, within 10%, within 5%, or within 1% of a stated value or of a stated limit of a range, and includes the exact stated value or range. The term “substantially” is defined as largely but not necessarily wholly what is specified (and includes what is specified; e.g., substantially 90 degrees includes 90 degrees and substantially parallel includes parallel), as understood by a person of ordinary skill in the art. In any disclosed implementation, the term “substantially” may be substituted with “within [a percentage] of” what is specified, where the percentage includes 0.1, 1, or 5 percent; and the term “approximately” may be substituted with “within 10 percent of” what is specified. The statement “substantially X to Y” has the same meaning as “substantially X to substantially Y,” unless indicated otherwise Likewise, the statement “substantially X, Y, or substantially Z” has the same meaning as “substantially X, substantially Y, or substantially Z,” unless indicated otherwise. The phrase “and/or” means and or. To illustrate, A, B, and/or C includes: A alone, B alone, C alone, a combination of A and B, a combination of A and C, a combination of B and C, or a combination of A, B, and C. In other words, “and/or” operates as an inclusive or. Similarly, the phrase “A, B, C, or a combination thereof” or “A, B, C, or any combination thereof” includes: A alone, B alone, C alone, a combination of A and B, a combination of A and C, a combination of B and C, or a combination of A, B, and C. 
     Throughout this document, values expressed in a range format should be interpreted in a flexible manner to include not only the numerical values explicitly recited as the limits of the range, but also to include all the individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly recited. For example, a range of “about 0.1% to about 5%” or “about 0.1% to 5%” should be interpreted to include not just about 0.1% to about 5%, but also the individual values (e.g., 1%, 2%, 3%, and 4%) and the sub-ranges (e.g., 0.1% to 0.5%, 1.1% to 2.2%, 3.3% to 4.4%) within the indicated range. 
     The terms “comprise” (and any form of comprise, such as “comprises” and “comprising”), “have” (and any form of have, such as “has” and “having”), and “include” (and any form of include, such as “includes” and “including”). As a result, an apparatus that “comprises,” “has,” or “includes” one or more elements possesses those one or more elements, but is not limited to possessing only those one or more elements. Likewise, a method that “comprises,” “has,” or “includes” one or more steps possesses those one or more steps, but is not limited to possessing only those one or more steps. 
     Any implementation of any of the systems, methods, and article of manufacture can consist of or consist essentially of—rather than comprise/have/include—any of the described steps, elements, and/or features. Thus, in any of the claims, the term “consisting of” or “consisting essentially of” can be substituted for any of the open-ended linking verbs recited above, in order to change the scope of a given claim from what it would otherwise be using the open-ended linking verb. Additionally, the term “wherein” may be used interchangeably with “where”. 
     Further, a device or system that is configured in a certain way is configured in at least that way, but it can also be configured in other ways than those specifically described. The feature or features of one implementation may be applied to other implementations, even though not described or illustrated, unless expressly prohibited by this disclosure or the nature of the implementations. Some details associated with the implementations are described above, and others are described below. Other implementations, advantages, and features of the present disclosure will become apparent after review of the entire application, including the following sections: Brief Description of the Drawings, Detailed Description, and the Claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following drawings illustrate by way of example and not limitation. For the sake of brevity and clarity, every feature of a given structure is not always labeled in every figure in which that structure appears. Identical reference numbers do not necessarily indicate an identical structure. Rather, the same reference number may be used to indicate a similar feature or a feature with similar functionality, as may non-identical reference numbers. The figures are drawn to scale (unless otherwise noted), meaning the sizes of the depicted elements are accurate relative to each other for at least the implementation depicted in the figures. Views identified as schematics are not drawn to scale. 
         FIG. 1  is a diagram that illustrates an example of a system for performing distillation that includes a tray with through holes having different diameters. 
         FIG. 2  illustrates a top view of a first implementation of a plate that includes through holes having different diameters. 
         FIG. 3  illustrates a top view of a second implementation of a plate that includes through holes having different diameters. 
         FIGS. 4A and 4B  illustrate schematic sectional views of the first implementation and the second implementation of the plate. 
         FIGS. 5A and 5B  illustrate top views of multiple plates having through holes with different diameters. 
         FIG. 6  illustrates a top view of a third implementation of a plate that includes through holes having different diameters. 
         FIG. 7  illustrates a top view of a fourth implementation of a plate that includes through holes having different diameters. 
         FIG. 8  is a block diagram of an example of a system for fabricating a tray having through holes with different diameters. 
         FIG. 9  is a flowchart of an example of a method of fabricating a distillation tray. 
     
    
    
     DETAILED DESCRIPTION OF ILLUSTRATIVE IMPLEMENTATIONS 
     Referring to  FIG. 1 , a diagram of a system  100  for performing distillation is shown. The system  100  includes at least one tray that includes through holes of different diameters, as further described herein. As used herein, through holes may also be referred to as perforations. 
     System  100  includes a distillation column (e.g., column  102 ), a condenser  104 , and a reboiler  106 . Column  102  is coupled to condenser  104  via conduits, such as a tubes, and column  102  is coupled to reboiler  106  via conduits, such as tubes. In some implementations, system  100  includes additional components, such as one or more pumps, gravity separators, additional condensers, or a combination thereof, which are not shown for convenience. 
     The column  102  includes a housing  110  defining a chamber  112  and a plurality of trays positioned within the chamber. For example, the plurality of trays may include an illustrative first tray  114  and an illustrative second tray  116 . Second tray  116  may be positioned proximate (e.g., below, in the orientation shown in  FIG. 1 ) to first tray  114  within chamber  112 . In a particular implementation, a diameter of at least one tray is greater than or equal to two meters (e.g., as small as 2 to 3 meters (m)). Alternatively, the diameter may be as large as seven meters. Although twelve trays are shown in  FIG. 1 , in other implementations, column  102  may include fewer than twelve or more than twelve trays. At least some of the plurality of trays do not have downcomers. Downcomers are conduits that guide liquid from an upper tray to a lower tray. In a particular implementation, each tray of the plurality of trays does not have downcomers. Additionally, at least one of the trays, such as first tray  114 , may include a plate with a plurality of through holes, the plurality of through holes including a first set of through holes each having substantially a first diameter and a second set of through holes each having substantially a second diameter that is different than the first diameter, in addition to a weir extending from a surface of the plate and disposed between the sets of through holes, as further described herein at least with reference to  FIGS. 2-3 and 6-7 . 
     In a particular implementation, column  102  is a cylindrical column. For example, column  102  may have a diameter of up to 7 m (e.g., between 5 and 7 m). The trays may be supported on vessel wall rings along housing  110  using tray ends along with cross bars for large diameters (when needed). Alternatively, the plurality of trays may be supported by a support structure that extends vertically along housing  110 . In a particular implementation, the support structure is steel. In other implementations, other metals or materials may be used. In some implementations, the plurality of trays each include a support beam, or other support structure, coupled to a surface (e.g., a bottom surface) of the trays to support the weight of the trays and keep the trays from bending or bowing. 
     Column  102  is configured to distill (e.g., to separate) a liquid feed including a mixture of multiple liquids into the component parts. This is accomplished by heating the liquid feed to a temperature above a boiling point of one of the components but below a boiling point of another component. As the liquid feed is heated (e.g., by a heating unit of column  102 ), one of the components (in liquid form) flows down (e.g., from higher trays to lower trays) through holes in the plurality of trays while another of the components is converted to vapor (e.g., gas), which flows up the plurality of trays through the holes. 
     Condenser  104  is coupled to column  102  and configured to receive the vapor from the distillation column. Condenser  104  is configured to cool the vapor such that the vapor converts to a liquid. Because the vapor is substantially the component of the liquid feed with the lower boiling point, the liquid formed in the condenser is the liquid form of the lower boiling point component (that was originally mixed in the liquid feed). Condenser  104  is configured to provide some of this liquid as an output product and to provide the rest of the liquid back to column  102  as reflux for use in the distillation process. 
     Reboiler  106  is coupled to column  102  and configured to receive the liquid from the distillation column. Some of this liquid (e.g., the liquid form of the component with the higher boiling point) is provided as an output product. Reboiler  106  is configured to boil the remainder of the liquid to convert the liquid to vapor. This vapor is returned to column  102  for use in the distillation process. 
     During operation of system  100 , column  102  receives liquid feed  120  at a first input. Liquid feed  120  includes a combination of at least two liquid components (e.g., chemicals). As an illustrative, non-limiting example, liquid feed  120  may include butane and isobutane. Liquid feed  120  is provided to one or more of the plurality of trays within column  102 , and, as liquid feed  120  is heated, vapor of the first component flows up the plurality of trays while liquid of the second component flows down the plurality of trays. For example, liquid may flow down from first tray  114  to second tray  116  via through holes in the first tray, and vapor  122  may flow up from the second tray to the first tray via the through holes. 
     As vapor  122  (that is substantially the first component) rises to the top of column  102 , vapor  122  is provided from a first output port of the distillation column to condenser  104 . Condenser  104  cools vapor  122  to convert the vapor to liquid (e.g., a liquid form of substantially the first component). A first portion of this liquid is provided as reflux  124  to a second input port of column  102  for use in the distillation process. A second portion of this liquid is provided as first output product  126  (e.g., liquid of the first component). 
     Additionally, as the liquid in column  102  flows toward the bottom, the liquid (which is substantially the second component) exits the distillation chamber via a second output port as liquid  128 . A first portion of liquid  128  is provided as second output product  130  (e.g., liquid of the second component). A second portion of liquid  128  is provided to reboiler  106 . Reboiler  106  heats liquid  128  to convert the liquid to vapor (e.g., a gas), and the vapor is provided as return vapor  132  to a third input port of column  102  for use in the distillation process. 
     System  100  includes trays that are less complex and less costly to fabricate than conventional trays. For example, as further described herein, at least one tray of column  102  includes through holes having different diameters and no downcomers. Such a tray is less complex and less costly to fabricate than a typical sieve tray with downcomers. Additionally, such a tray is easier to clean, which reduces downtime of system  100  for cleaning, and/or is less likely to be fouled by rust and/or debris, thereby extending the useful life of the tray. 
     Referring to  FIG. 2 , a plate  200  that includes through holes (e.g., perforations) having different diameters is shown. A tray, such as a distillation tray, may include plate  200 . In a particular implementation, trays  114  and/or  116  of  FIG. 1  include plate  200 . Plate  200  includes a plurality of through holes extending from a first surface (e.g., a top surface) to a second surface (e.g., a bottom surface). The plurality of through holes includes a first set of first through holes  210  and a second set of second through holes  212 . First through holes  210  include through holes having a first diameter, such as illustrative first through hole  214 . Second through holes  212  include through holes having a second diameter that is different than the first diameter, such as illustrative second through hole  216 . 
     In a particular implementation, the second diameter is larger than the first diameter. In other implementations, the second diameter is less than the first diameter. In a particular implementation, the first diameter is one of substantially 19 millimeters (mm), 12.5 mm, or 4.75 mm, and the second diameter is one of substantially 19 mm, 12.5 mm, or 4.75 mm but not equal to the first diameter. For example, the first diameter may be substantially 12.5 mm and the second diameter may be substantially 19 mm. As another example, the first diameter may be substantially 4.75 mm, and the second diameter may be substantially 12.5 mm. As another example, the first diameter may be substantially 4.75 mm, and the second diameter may be substantially 19 mm. In a particular implementation, the first diameter is between 4.75 mm to 12.5 mm (or between 0.1875 and 0.5 inches), and the second diameter is between 12.5 mm and 19 mm (or between 0.5 and 0.75 inches). In other aspects, other size diameters are possible. 
     Plate  200  also includes weirs separating regions with first through holes  210  from regions with second through holes  212 . The weirs are coupled to plate  200  and extend from the first surface (e.g., top surface) of the plate. For example, plate  200  includes a first weir  202  coupled to the plate and extending from the first surface. First weir  202  is positioned between a first set of first through holes  210  and second set of second through holes  212 . In a particular implementation, the first set of first through holes  210  include a first plurality of through holes, and the second set of second through holes  210  include a second plurality of through holes, as shown in  FIG. 2 . 
     In the particular implementation shown in  FIG. 2 , regions of first through holes  210  are interspersed with regions of second through holes  212 , and weirs are disposed between the regions of different through hole sizes. For example, plate  200  includes a first set of first through holes  210 , a second set of second through holes  212 , a third set of first through holes  210 , and a fourth set of second through holes  212 . Plate  200  also includes first weir  202 , a second weir  204 , a third weir  206 , and a fourth weir  208  that are coupled to the plate and that extend from a first surface (e.g., a top surface) of the plate. Weirs  202 - 208  extend linearly and are positioned in parallel across plate  200 . First weir  202  is positioned between the first set of first through holes  210  and the second set of second through holes  212  and second weir  204  is positioned between the second set of second through holes  212  and the third set of first through holes  210 , such that the first set of first through holes  210  are disposed on an opposite side of first weir  202  than the second set of second through holes  212 , and the second set of second through holes  212  are disposed between first weir  202  and second weir  204 . In a particular implementation, the first set of first through holes  210  are disposed between first weir  202  and another weir. Third weir  206  is positioned between the third set of first through holes  210  and the fourth set of second through holes  212  and fourth weir  208  is positioned between the fourth set of second through holes  212  and a fifth set of first through holes  210  such that the third set of first through holes  210  are disposed between second weir  204  and third weir  206 , and the fourth set of second through holes  212  are disposed between third weir  206  and fourth weir  208 . Although six regions of first through holes  210 , five regions of second through holes  212 , and ten weirs are shown, in other implementations, different numbers of regions with first through holes  210 , different numbers of regions with second through holes  212 , and different numbers of weirs are possible. 
     Weirs  202 - 208  are pieces of metal (or other material) that extend from the surface of plate  200  and are configured to maintain a particular liquid level within a region of the plate (e.g., when a liquid level exceeds the height of the weir, the liquid is able to flow over the weir into another region). Weirs are typically rectangular, though in other implementations the weirs have other shapes. In a particular implementation, weirs  202 - 208  have heights between approximately two to four inches (e.g., weirs  202 - 208  extend approximately two to approximately four inches from plate  200 ). In other implementations, the heights may be less than two or more than four inches. 
     The sets of through holes are configured to enable liquid to flow from the first surface to the second surface and below plate  200  without use of downcomers. For example, if plate  200  is included in first tray  114 , the sets of through holes enable liquid to flow down to second tray  116 . First through holes  210  are sized such that vapor may also flow (e.g., bubble up) from second tray  116  to first tray  114  (e.g., plate  200 ), while second through holes  212  are sized to provide fast enough fluid downflow to substantially prevent vapor from flowing up (or to prevent an appreciable amount of vapor from flowing up). Because liquid is able to flow down first through holes  210  and second through holes  212 , and vapor is able to flow up first through holes  210 , plate  200  (e.g., first tray  114 ) is configured to operate similar to a distillation tray with multiple downcomers. However, plate  200  does not include any downcomers, which simplifies the fabrication and reduces the cost of the plate. 
     In a particular implementation, first through holes  210  and second through holes  212  can have measurements according to Table 1. 
     
       
         
           
               
               
               
               
               
             
               
                   
                 TABLE 1 
               
               
                   
                   
               
             
            
               
                   
                 U.S. Hole Diameter (inches) 
                 ¾ 
                 ½ 
                  3/16 
               
               
                   
                 Tolerance (inches) 
                 0.38 
                 0.28 
                 0.21 
               
               
                   
                 Metric Hole Diameter (mm) 
                 19 
                 12.5 
                 4.75 
               
               
                   
                 Tolerance (mm) 
                 0.015 
                 0.011 
                 0.008 
               
               
                   
                   
               
            
           
         
       
     
     In another particular implementation, first through holes  210  and second through holes  212  can have measurements according to Table 2. 
                                         TABLE 2               IPA   Perforations   Centers   Holes per               Numbers   (inches)   (inches)   square inch   Open Area   Line                                                        118     3/16   ¼   19   51%   Staggered       128   ½    11/16   2   47%   Staggered       103   ½    11/16   3   53%   Straight       131   ¾   1   1   51%   Staggered       204   ¾   1   1   56%   Straight                    
In Table 2, perforations refer to the diameter of the through holes (e.g., first through holes  210  or second through holes  212 ), centers refers to the spacing between adjacent through holes, open area refers to the space of a corresponding region not occupied by through holes, and line refers to the orientation of the through holes (relative to each other) within a region.
 
     Table 3 shows vapor and liquid loading and flooding performance of a tray in a NC4, IC4 isomer separation column. 
     
       
         
           
               
               
               
               
             
               
                   
                 TABLE 3 
               
               
                   
                   
               
             
            
               
                   
                 Liquid rate 
                 3801000 
                 kilograms(kg)/hour(hr) 
               
               
                   
                 Vapor rate 
                 1905596 
                 kg/hr 
               
               
                   
                 Molecular weight liquid 
                 58 
                 kg/kgmol 
               
               
                   
                 Molecular weight vapor 
                 58 
                 kg/kgmol 
               
               
                   
                 Liquid density 
                 650 
                 kg/m 3   
               
               
                   
                 Vapor density 
                 14.01 
                 kg/m 3   
               
            
           
           
               
               
               
            
               
                   
                 Flood parameters 
                 0.29 
               
            
           
           
               
               
               
               
            
               
                   
                 Csb 
                 0.25 
                 feet(ft)/second(s) 
               
               
                   
                 Csb 
                 0.08 
                 m/s 
               
               
                   
                 Flood velocity 
                 3.46 
                 m/s 
               
               
                   
                 Vapor velocity 
                 2.47 
                 m/s 
               
            
           
           
               
               
               
            
               
                   
                 % of flood 
                 71.53% 
               
               
                   
                   
               
            
           
         
       
     
     In Table 4, measurements of a non-circular straight weir type layout that segregates small and large perforation areas as segments of a circular column diameter are shown. AD refers to segment area (in m 2 ) and H/D refers to chord height/distillation column diameter. The reference formulas used for Table 4 are those of chords of a circle and section areas of a circle on either side of the chord. The data in Table 4 is developed for a column 6 meters in internal diameter, with cross-sectional area 28.2743 m 2 , having a total of ten areas with large perforation holes. In this implementation, corresponding weir loading is 20.18 gallon per minute/inch (gpm/inch) weir length. 
     
       
         
           
               
               
               
               
               
               
               
             
               
                 TABLE 4 
               
               
                   
               
               
                   
                   
                   
                   
                   
                   
                 Small 
               
               
                 Number of 
                   
                   
                 Large 
                 Large 
                 Unperforated 
                 perforation 
               
               
                 downcomer- 
                   
                   
                 perforation 
                 perforation 
                 sieve tray 
                 sieve hole 
               
               
                 like zones 
                   
                   
                 exit hole 
                 inlet area 
                 deck area 
                 tray deck 
               
               
                 plus one 
                 (H/D) 
                 (AD) 
                 area (m 2 ) 
                 (m 2 ) 
                 (m 2 ) 
                 area (m 2 ) 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 0 
                 0 
                 0 
                 0 
                   
                 0 
                 0 
               
               
                 1 
                 0.0909 
                 1.2792 
                 0.0284 
                 0.4147 
                 1.2792 
                 0.6524 
               
               
                 2 
                 0.1818 
                 3.5112 
                 0.0567 
                 0.5428 
                 2.2320 
                 1.1383 
               
               
                 3 
                 0.2727 
                 6.2465 
                 0.0851 
                 0.6211 
                 2.7353 
                 1.3950 
               
               
                 4 
                 0.3636 
                 9.2896 
                 0.1134 
                 0.6674 
                 3.0431 
                 1.5520 
               
               
                 5 
                 0.4545 
                 12.5031 
                 0.1418 
                 0.6882 
                 3.2134 
                 1.6388 
               
               
                 6 
                 0.5455 
                 15.7713 
                 0.1418 
                 0.6858 
                 3.2682 
                 1.6668 
               
               
                 7 
                 0.6364 
                 18.9847 
                 0.1134 
                 0.6599 
                 3.2134 
                 1.6388 
               
               
                 8 
                 0.7273 
                 22.0278 
                 0.0851 
                 0.6076 
                 3.0431 
                 1.5520 
               
               
                 9 
                 0.8182 
                 24.7631 
                 0.0567 
                 0.5210 
                 2.7353 
                 1.3950 
               
               
                 10 
                 0.9091 
                 26.9951 
                 0.0284 
                 0.3769 
                 2.2320 
                 1.1383 
               
               
                 11 
                 1 
                 28.2743 
                   
                 0.4147 
                 1.2792 
                 0.6524 
               
               
                 Total Areas 
                   
                   
                 0.506 
                 6.2001 
                 28.2743 
                 14.4199 
               
               
                   
               
            
           
         
       
     
     Although first through holes  210  and second through holes  212  are described as having the same diameter, in other implementations, the through holes may have diameters selected from within the same range. To illustrate, a first set of through holes (e.g., first through holes  210  to the left of first weir  202  in  FIG. 2 ) may each have a first diameter within a first range, a second set of through holes (e.g., second through holes  212  between first weir  202  and second weir  204 ) may each have a second diameter within a second range that is different than the first range, a third set of through holes (e.g., first through holes  210  between second weir  204  and third weir  206 ) may have a third diameter within the first range, and a fourth set of through holes (e.g., second through holes  212  between third weir  206  and fourth weir  208 ) may have a fourth diameter within the second range. In a particular implementation, the first range is between 4.75 mm to 12.5 mm (or between 0.1875 and 0.5 inches), and the second range is between 12.5 mm and 19 mm (or between 0.5 and 0.75 inches). Thus, in some implementations, different regions of first through holes  210  and different regions of second through holes  212  may have different diameters within a corresponding range. In some implementations, the weirs may define different areas having through holes with different diameters. For example, first through holes  210  in an area defined by a first group of weirs may have different diameters than first through holes  210  in a second area defined by a second group of weirs. 
     Plate  200  thus enables liquid to flow through first through holes  210  and second through holes  212 , and vapor to flow through first through holes  210 . Because liquid and vapor can flow in this manner, downcomers are not used. This reduces the complexity and cost of fabricating plate  200 . Additionally, cleaning may be easier and plate  200  may be less likely to be fouled by rust and/or debris, thereby extending the useful life of plate  200 . 
     Referring to  FIG. 3 , a plate  300  that includes through holes having different diameters is shown. A tray, such as a distillation tray, may include plate  300 . In a particular implementation, trays  114  and/or  116  of  FIG. 1  may include plate  300 . Plate  300  includes a plurality of through holes extending from a first surface (e.g., a top surface) to a second surface (e.g., a bottom surface). The plurality of through holes includes a first set of first through holes  310  and a second set of second through holes  312 . First through holes  310  include through holes having a first diameter, such as illustrative first through hole  314 . Second through holes  312  include through holes having a second diameter that is different than the first diameter, such as illustrative second through hole  316 . In a particular implementation, the second diameter is greater than the first diameter, and the first and second diameters may have measurements as described with reference to  FIG. 2 . For example, first through holes  310  may include or correspond to the first through holes  210  of  FIG. 2 , and second through holes  312  may include or correspond to second through holes  212  of  FIG. 2 . 
     In the particular implementation shown in  FIG. 3 , regions of first through holes  310  are interspersed with regions of second through holes  312 , and weirs are disposed between the regions of different through hole sizes. For example, plate  300  includes a first set of first through holes  310 , a second set of second through holes  312 , a third set of first through holes  310 , and a fourth set of second through holes  312 . Plate  300  also includes first weir  302 , a second weir  304 , a third weir  306 , and a fourth weir  308  that are coupled to the plate and that extend from a first surface (e.g., a top surface) of the plate. Weirs  302 - 308  define concentric circles, and regions containing the first through holes  310  and the second through holes  312  define concentric circular regions. Weirs are disposed between circular regions of through holes having different diameters. For example, the first set of first through holes  310  are disposed outside first weir  302 , the second set of through holes  312  are disposed between first weir  302  and second weir  304 , the third set of first through holes  310  are disposed between second weir  304  and third weir  306 , and the fourth set of second through holes  312  are disposed between third weir  306  and fourth weir  308 . Although three regions of first through holes  310 , two regions of second through holes  312 , and four weirs are shown in  FIG. 3 , in other implementations, plate  300  includes a different number of regions of first through holes  310 , a different number of regions of second through holes  312 , and/or a different number of weirs. 
     In a particular implementation, capacity design of plate  300  is given by Table 5. 
     
       
         
           
               
               
               
               
               
             
               
                 TABLE 5 
               
               
                   
               
               
                 Large 
                 Large 
                   
                   
                   
               
               
                 perforation 
                 perforation 
                 Outer 
                 Inner 
                 Weir 
               
               
                 outer circle (m) 
                 inner circle (m) 
                 weir (m) 
                 weir (m) 
                 length (m) 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
            
               
                 2 
                 1.85 
                 6.28 
                 5.81 
                 12.10 
               
               
                 4 
                 3.85 
                 12.57 
                 12.10 
                 24.66 
               
               
                   
               
            
           
         
       
     
     In a particular implementation, corresponding gpm/inch weir length in just two circular large perforation areas (e.g., regions of second through holes  312 ) is 17.79 gpm/inch. Such measurements are based on process data from n butane and isobutane binary isomer separation. 
     The configuration of plate  300  increases the length of the weirs, as compared to plate  200  of  FIG. 2 . Increasing the weir lengths can reduce weir loadings, in some implementations by as much as a factor of five compared to linear weirs. Thus, plate  300  may be suitable for higher liquid loading levels than plate  200 . For example, plate  300  may be suitable for 20 gpm/inch or higher liquid loading levels, such as in C3 splitter, C4 isomer separations or butyraldehyde isomer separations. 
     Referring to  FIGS. 4A-4B , schematic sectional views of plate  200  and plate  300  are shown. Referring to  FIG. 4A , plate  200  includes a first surface  402  (e.g., a top surface) and a second surface  404  (e.g., a bottom surface) opposite to first surface  402 . Through holes extend from first surface  402  to second surface  404  (e.g., through an entire thickness of plate  200 ). For example, first through holes  210  and second through holes  212  extend from first surface  402  to second surface  404 , thereby enabling liquid to flow from first surface  402  to the second surface  404  and below plate  200  (or vapor to flow from beneath second surface  404  to above first surface  402 ). 
     Weirs are coupled to first surface  402  and extend from first surface  402 . For example, first weir  202 , second weir  204 , third weir  206 , and fourth weir  208  are coupled to and extend from first surface  402 . Weirs  202 - 208  are disposed in parallel and between regions of through holes with different diameters. For example, first weir  202  is disposed between a first set of first through holes  210  and a second set of second through holes  212 , second weir  204  is disposed between the second set of second through holes  212  and a third set of first through holes  210 , third weir  206  is disposed between the third set of first through holes  210  and a fourth set of second through holes  212 , and fourth weir  208  is disposed between the fourth set of second through holes  212  and a fifth set of first through holes  210  (not shown). In some implementations, one or more support structures may be coupled to second surface  404  to support plate  200  and to keep plate  200  from bending or bowing. 
     Referring to  FIG. 4B , plate  300  includes a first surface  406  (e.g., a top surface) and a second surface  408  (e.g., a bottom surface) opposite to first surface  406 . Through holes extend from first surface  406  to second surface  408  (e.g., through an entire thickness of plate  300 ). For example, first through holes  310  and second through holes  312  extend from first surface  406  to second surface  408 , thereby enabling liquid to flow from first surface  406  to second surface  408  and below plate  300  (or vapor to flow from beneath second surface  408  to above first surface  406 ). 
     Weirs are coupled to first surface  406  and extend from first surface  406 . For example, Weirs  306 ,  308  are coupled to and extend from first surface  406 . Weirs  306 ,  308  form concentric circles and are disposed between regions of through holes with different diameters. For example, third weir  306  is disposed between a set of second through holes  312  (not shown) and a set of first through holes  310 , and fourth weir  308  is disposed between the set of first through holes  310  and a set of second through holes  312 . 
     Referring to  FIGS. 5A-5B , top views of multiple plates are shown. Although different plates are shown in  FIGS. 5A-5B , such example is not limiting, and in other implementations, one or more of the plates of  FIG. 5A  may be used with one or more of the plates of  FIG. 5B . 
       FIG. 5A  shows first plate  502  and second plate  504 . In a particular implementation, first plate  502  is included in first tray  114  and second plate  504  is included in second tray  116  such that first plate  502  is disposed above and over second plate  504  in distillation column  102 . Plates  502 ,  504  include regions having first through holes  506  (with a first diameter) and regions having second through holes  508  (with a second diameter that is different than the first diameter). In a particular implementation, first through holes  506  include or correspond to first through holes  210  of  FIG. 2 , and second through holes  508  include or correspond to second through holes  212  of  FIG. 2 . Weirs are coupled to plates  502 ,  504 . For example, weir  510  is coupled to first plate  502 , and weir  512  is coupled to second plate  504 . 
     First plate  502  is configured in a first orientation  514 , and second plate  504  is configured in a second orientation  516  that is different than first orientation  514 . In a particular implementation, second orientation  516  is rotated substantially 90° (clockwise or counterclockwise) as compared to first orientation  514 . For example, first plate  502  includes a plurality of weirs extending from the first surface in parallel across the plate in first orientation  514 , and second plate  504  includes a second plurality of weirs extending from a surface of second plate  504  in parallel across the second plate in second orientation  516  that is perpendicular to first orientation  514 . To further illustrate, weirs extend up and down (in the orientation of  FIG. 5 ) on first plate  502 , and weirs extend left and right on second plate  504 . In other implementations, second orientation  516  is rotated by a different amount, such as substantially 15°, 30°, 45°, 60°, or 75°, as non-limiting examples. Adjacent plates (e.g., adjacent trays) are oriented in such a manner such that regions having first through holes  506  in first plate  502  are at least partially located above regions having second through holes  508  in second plate  504 , and regions having second through holes  508  in first plate  502  are located at least partially above regions having first through holes  506  in second plate  504 . 
       FIG. 5B  shows third plate  520  and fourth plate  522 . In a particular implementation, third plate  520  is included in first tray  114  and fourth plate  522  is included in second tray  116  such that third plate  520  is disposed above and over fourth plate  522  in distillation column  102 . Plates  520 ,  522  include regions having first through holes  506  (with a first diameter) and regions having second through holes  508  (with a second diameter that is different than the first diameter). In a particular implementation, first through holes  506  include or correspond to first through holes  310  of  FIG. 3 , and second through holes  508  include or correspond to second through holes  312  of  FIG. 3 . Weirs are coupled to plates  520 ,  522  and form concentric circles. 
     Third plate  520  is configured in a first configuration  524 , and fourth plate  522  is configured in a second configuration  526 . Configurations  524 ,  526  refer to locations of regions with first through holes  506 , regions with second through holes  508 , and weirs. First configuration  524  is different than second configuration  526 . For example, third plate  520  includes a plurality of weirs extending from a surface of the third plate and forming concentric circles that separate sets of through holes having the first diameter from sets of through holes having the second diameter. Fourth plate  522  includes a second plurality of weirs extending from a surface of the fourth plate and forming concentric circles that separate sets of through holes having the second diameter from sets of through holes having the first diameter. Adjacent plates may have different configurations such that regions having first through holes  506  in third plate  520  are at least partially located above regions having second through holes  508  in fourth plate  522 , and regions having second through holes  508  in third plate  520  are at least partially located above regions having first through holes  506  in fourth plate  522 . 
     Configuration of adjacent trays in this manner (e.g., by orienting adjacent trays differently or placing trays with different configurations adjacent to each other) may provide for a more even distribution of liquid to regions having first through holes  506  and regions having second through holes  508 . 
     Referring to  FIGS. 6 and 7 , a plate  600  and a plate  700  that include through holes having different diameters are shown. A tray, such as first tray  114  and/or second tray  116 , may include plate  600  or plate  700 .  FIGS. 6 and 7  show “hybrid” implementations that include both linear and circular weirs. 
     Referring to  FIG. 6 , plate  600  includes linear weirs that extend across plate  600 , regions of first through holes  610  that extend across plate  600 , and regions of second through holes  612  that extend across plate  600 . For example, plate  600  includes a first weir  602  and a second weir  604  that are coupled to a surface of plate  600  and positioned in parallel across the plate. A first set of first through holes  610  are disposed on an opposite side (e.g., a bottom side in the orientation shown in  FIG. 6 ) of first weir  602  than a second set of second through holes  612 . Second set of second through holes  612  are disposed between first weir  602  and second weir  604 . First through holes  610  have a first diameter, such as illustrative first through hole  614 , and second through holes  612  have a second diameter that is different than the first diameter, such as illustrative second through hole  616 . In a particular implementation, first through holes  610  include or correspond to first through holes  210  or  310 , and second through holes  612  include or correspond to second through holes  212  or  312 . 
     Plate  600  also includes circular weirs and circular regions of through holes. For example, plate  600  includes a third weir  606 , a fourth weir  608 , and a fifth weir  609  coupled to and extending from the surface (e.g., a top surface) of the plate. Weirs  606 - 609  define concentric circles or portions of concentric circles and separate regions of through holes with different diameters. For example, a third set of first through holes  610  are disposed between third weir  606  and fourth weir  608 , and a fourth set of second through holes  612  are disposed between fourth weir  608  and fifth weir  609 . Although  FIG. 6  shows four linear weirs and three circular weirs, in other implementations, more than four or fewer than four linear weirs and more than three or fewer than three circular weirs may be included. 
     Referring to  FIG. 7 , plate  700  includes circular weirs, circular regions of first through holes  610 , and circular regions of second through holes  612 . For example, plate  700  includes a first weir  702  and a second weir  704  coupled to and extending from a surface (e.g., a top surface) of the plate. First weir  702  and second weir  704  form (e.g., define) concentric circles. A first set of first through holes  610  are disposed outside first weir  702  and a second set of second through holes  612  are disposed between first weir  702  and second weir  704 . 
     Plate  700  also includes linear weirs and regions of through holes disposed within the circles formed by the circular weirs. For example, plate  700  includes a third weir  706  and a fourth weir  708  that are coupled to and extend from a surface of the plate. Third weir  706  and fourth weir  708  are positioned in parallel across a circle formed by second weir  704 . A third set of first through holes  610  are disposed between second weir  704  and third weir  706 , and a fourth set of second through holes  612  are disposed between third weir  706  and fourth weir  708 . Although  FIG. 7  shows two circular weirs and two linear weirs, in other implementations, more than two or fewer than two circular weirs and more than two or fewer than two linear weirs may be included. 
     The hybrid examples of  FIGS. 6-7  may provide benefits as compared to other trays. 
     For example, because some of the weirs are circular, the length of the weirs may be longer than linear weirs, which increases the liquid loading levels that can be handled by the corresponding plates. Additionally, or alternatively, some of the weirs and regions are linear, which may simplify a fabrication process. Additionally, the hybrid designs can be deployed in distillation columns that have higher vapor loading as compared to liquid loadings, or in distillation columns where jet flooding is a limiting factor. 
     The foregoing disclosed trays (and plates) may be designed and configured into computer files stored on a computer readable media. Some or all of such files may be provided to fabrication handlers who fabricate the trays based on such files. The trays are then installed into distillation columns for use in distillation processes, as described above.  FIG. 8  depicts an example of a system  800  for fabricating distillation trays. 
     Tray information  802  is received at a research/design computer  806 . Tray information  802  may include design information representing at least one physical property of a distillation tray, such as trays  114 ,  116 , and/or trays including plates  200 ,  300 ,  502 ,  504 ,  520 ,  522 ,  600 , or  700 . For example, tray information  802  may include locations of through holes having a first diameter, locations of through holes having a second diameter, the first diameter, the second diameter, and/or locations of weirs that are entered via a user interface  804  coupled to research/design computer  806 . Research/design computer  806  includes a processor  808 , such as one or more processing cores, coupled to a computer readable medium such as a memory  810 . Memory  810  may store computer readable instructions that are executable to cause processor  808  to transform tray information  802  into a design file  812 . Design file  812  may include information indicating a design for a distillation tray, such as the locations of through holes, the locations of weirs, the diameters of through holes, etc. Design file  812  may be in a format that is usable by other systems to perform fabrication, as further described herein. 
     Design file  812  is provided to a fabrication computer  814  to control fabrication equipment during a fabrication process for a tray  820  (e.g., a tray with no through holes or weirs). Fabrication computer  814  includes a processor  816  (e.g., one or more processors), such as one or more processing cores, and a memory  818 . Memory  818  may include executable instructions such as computer-readable instructions or processor-readable instructions that are executable by a computer, such as processor  816 . The executable instructions may enable processor  816  to control fabrication equipment, such as by sending one or more control signals or data, during a fabrication process for tray  820  (e.g., a tray with no through holes and weirs). In some implementations, the fabrication system (e.g., an automated system that performs the fabrication process) may have a distributed architecture. For example, a high-level system (e.g., processor  816 ) may issue instructions to be executed by controllers of one or more lower-level systems (e.g., individual pieces of fabrication equipment). The lower-level systems may receive the instructions, may issue sub-commands to subordinate modules or process tools, and may communicate status back to the high-level system. Thus, multiple processors (e.g., processor  816  and one or more controllers) may be distributed in the fabrication system. 
     The fabrication equipment includes first fabrication equipment  822 , second fabrication equipment  824 , optional planarizer  826 , and third fabrication equipment  828 . First fabrication equipment  822  is configured to form a first set of through holes extending through a first surface of a plate (of tray  820 ) and a second surface of a plate. The second surface is opposite to the first surface. The first set of through holes each have substantially a first diameter. Second fabrication equipment  824  is configured to form a second set of through holes extending through the first surface and the second surface. The second set of through holes each have substantially a second diameter that is different than the first diameter. 
     In a particular implementation, first fabrication equipment  822  includes a tool having multiple extensions. For example, the tool, which may be a die, includes substantially circular extensions that extend from a surface of the tool and have substantially the first diameter. In this implementation, the tool is configured to be pressed against the plate to form (e.g., punch) the first set of through holes. Second fabrication equipment  824  may include a similar tool. In alternate implementations, first fabrication equipment  822 , second fabrication equipment  824 , or both include one or more drills. In another implementation, first fabrication equipment  822 , second fabrication equipment  824 , or both include an etching device. 
     Planarizer  826  is configured to planarize the first surface, the second surface, or both. For example, planarizer  826  may planarize the first surface, the second surface, or both after formation of the first set of through holes, the second set of through holes, or both. Planarizing the surfaces may make it easier to attach weirs to the surfaces. 
     Third fabrication equipment  828  is configured to attach a weir to the first surface between the first set of through holes and the second set of through holes. For example, weirs may be attached as described with reference to  FIGS. 2-7 . In a particular implementation, third fabrication equipment  828  includes a device configured to bond the weir to the first surface, such as using a welding. 
     Fabrication computer  814  may be configured to initiate one or more operations of first fabrication equipment  822 , second fabrication equipment  824 , planarizer  826 , and third fabrication equipment  828 . For example, processor  816  may execute instructions stored at memory  818  to perform operations including initiating formation of the first set of through holes extending between the first surface and the second surface. The operations include initiating formation of the second set of through holes extending between the first surface and the second surface. In a particular implementation, formation of the first set of through holes and the second set of through holes is initiated at least partially concurrently. In an alternate implementation, formation of the second set of through holes is initiated after formation of the first set of through holes. The operations further include initiating attachment of the weir to the first surface between the first set of through holes and the second set of through holes. In some implementations, the operations further include initiating planarization of the first surface, the second surface, or both. 
     Performing the fabrication operations on tray  820  operates to form tray  830 . Tray  830  includes through holes having different diameters, such as a first set of through holes each having substantially a first diameter and a second set of through holes each having substantially a second diameter that is different than the first diameter. For example, tray  830  may include or correspond to trays  114 ,  116 , and/or trays that include plates  200 ,  300 ,  502 ,  504 ,  520 ,  522 ,  600 , or  700 . Tray  830  may be included in a distillation column, such as distillation column  102 . 
     System  800  enables fabrication of a distillation tray without downcomers, which is less complex and has less cost than fabrication of a distillation tray with downcomers. Additionally, cleaning of the distillation tray without downcomers is easier and more effective, leading to less downtime for cleaning and an increased useful life of the distillation tray. 
     Referring to  FIG. 9 , an example of a method of fabricating a distillation tray is shown. Method  900  may be performed by a manufacturing device or system, such as system  800  (e.g., first fabrication equipment  822 , second fabrication equipment  824 , and third fabrication equipment  828 ) of  FIG. 8 . The distillation tray formed by the method  900  may include or correspond to trays  114 ,  116 , and/or trays including plates  200 ,  300 ,  502 ,  504 ,  520 ,  522 ,  600 , or  700 , as non-limiting examples. 
     Method  900  includes forming a first set of through holes extending between a first surface of a plate and a second surface of the plate, at  902 . The second surface is opposite to the first surface. The first set of through holes have a first diameter. For example, first fabrication equipment  822  may form a first set of first through holes  210  in plate  200 . 
     Method  900  includes forming a second set of through holes extending between the first surface and the second surface, at  904 . The second set of through holes have a second diameter that is different from the first diameter. For example, second fabrication equipment  824  may form a second set of second through holes  212  in plate  200 . Forming the first set of through holes and the second set of through holes may include punching, drilling, or etching the first set of through holes and the second set of through holes, as non-limiting examples. In a particular implementation, the first set of through holes and the second set of through holes are formed at least partially concurrently. In an alternate implementation, the second set of through holes is formed after formation of the first set of through holes. 
     Method  900  also includes attaching a weir to the first surface between the first set of through holes and the second set of through holes, at  906 . For example, third fabrication equipment  828  may attach first weir  202  between the first set of first through holes  210  and the second set of second through holes  212 . Attaching the weir may include bonding the weir to the first surface, such as by welding the weir to the first surface. 
     In a particular implementation, method  900  further includes planarizing the first surface, the second surface, or both. For example, the surfaces may be planarized after forming the first set of through holes, the second set of through holes, or both. 
     Method  900  enables fabrication of a distillation tray without downcomers. Because there are no downcomers, fabrication of the distillation tray may be easier and less expensive then fabrication of a distillation tray with downcomers. Additionally, cleaning of the distillation tray may be easier, which reduces an amount of downtime for cleaning and extends the useful life of the distillation tray. 
     The above specification and examples provide a complete description of the structure and use of illustrative implementations. Although certain implementations have been described above with a certain degree of particularity, or with reference to one or more individual implementations, those skilled in the art could make numerous alterations to the disclosed implementations without departing from the scope of this disclosure. As such, the various illustrative implementations of the methods and systems are not intended to be limited to the particular forms disclosed. Rather, they include all modifications and alternatives falling within the scope of the claims, and implementations other than the one shown may include some or all of the features of the depicted implementations. For example, elements may be omitted or combined as a unitary structure, connections may be substituted, or both. Further, where appropriate, aspects of any of the examples described above may be combined with aspects of any of the other examples described to form further examples having comparable or different properties and/or functions, and addressing the same or different problems. Similarly, it will be understood that the benefits and advantages described above may relate to one implementation or may relate to several implementations. Accordingly, no single implementation described herein should be construed as limiting and implementations of the disclosure may be suitably combined without departing from the teachings of the disclosure. 
     The claims are not intended to include, and should not be interpreted to include, means-plus- or step-plus-function limitations, unless such a limitation is explicitly recited in a given claim using the phrase(s) “means for” or “step for,” respectively.