Abstract:
A vessel tray clamp is provided. The vessel tray clamp includes a distal end lying in a first plane and having a first width. The vessel tray clamp also includes a proximate end lying in a second plane that is not the first plane. The proximate end has a second width greater than the first width and has an elongated opening therethrough. An arcuate intermediate portion interconnects the distal end and proximate end. The arcuate intermediate portion has the first width adjacent the distal end and the second width adjacent the proximate end to form a shoulder therebetween.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention generally relates to clamps for use in vessels, and more particularly relates to clamps for securing trays to support structures of vessels. 
       BACKGROUND OF THE INVENTION 
       [0002]    Vessels, such as, hydroprocessing vessels, reactors, absorbers, strippers, and distillation columns, typically utilize trays for vapor-liquid contacting. Often, trays are installed during initial construction of the vessel, as well as removed and installed during vessel downtime for maintenance or refurbishing. Bolts and nuts may be used to secure the tray to a support ring positioned along an internal circumference of the vessel. Typically, such fasteners are used with J-shaped clamps. 
         [0003]    However, traditional bolts and nuts and J-shaped clamps can suffer from several disadvantages when used in vessels. Particularly, installing a nut and bolt arrangement without a clamp can require extensive time and labor. Further, lining up a bolt with a J-shaped clamp while holding the J-shaped clamp in position before fastening can be very difficult. Also, keeping the J-shaped clamp in proper orientation with the support structure while tightening the fastener can be difficult when the installer is positioned on one side of a tray. 
         [0004]    Accordingly, it is desirable to provide a clamp for securing trays inside a vessel that overcomes these disadvantages. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings and this background of the invention. 
       SUMMARY OF THE INVENTION 
       [0005]    Vessel tray clamps for securing a tray and a support structure in a vessel are provided. In accordance with one exemplary embodiment, the vessel tray clamp includes a distal end lying in a first plane and having a first width. The vessel tray clamp also includes a proximate end lying in a second plane that is not the first plane. The proximate end has a second width greater than the first width and is formed with an elongated opening therethrough. An arcuate intermediate portion interconnects the distal end and proximate end. The arcuate intermediate portion is formed with the first width adjacent the distal end and the second width adjacent the proximate end to form a shoulder therebetween. 
         [0006]    In another embodiment, a vessel tray clamp for securing a tray to a support structure in a vessel is provided. The support structure includes a topside and an underside, and the tray includes an upper surface and a lower surface for resting on the topside of the support structure. The vessel tray clamp has a distal end configured to be inserted from the upper surface of the tray through the tray for abutment with the underside of the support structure. Also, the vessel tray clamp includes an intermediate portion configured to be received in and engage the tray. Engagement of the intermediate portion with the tray substantially limits movement of the clamp to within a single plane. Further, the vessel tray clamp has a proximate end configured for engagement with the tray by a selectable engagement force. The vessel tray clamp is configured to increase compression force on the support structure by the clamp and the tray when the engagement force is increased. 
         [0007]    In accordance with another exemplary embodiment, a clamp for securing a tray to a support structure in a vessel is provided. The support structure includes a topside and an underside, and the tray includes an upper surface and a lower surface for resting on the topside of the support structure. The vessel tray clamp has a distal end configured to be inserted from the upper surface of the tray through the tray for abutment with the underside of the support structure. Also, the vessel tray clamp includes an intermediate portion configured to be received in and engage the tray. Further, the vessel tray clamp has a proximate end configured to receive a fastener to engage the clamp and the tray to control a selectable engagement force therebetween. The vessel tray clamp is configured to have a single orientation for installation and to hold a stationary position when the fastener is received during installation. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The present invention will hereinafter be described in conjunction with the following drawing figures, wherein like numerals denote like elements, and wherein: 
           [0009]      FIG. 1  is a side cross-sectional view of a vessel using a vessel tray clamp in accordance with an exemplary embodiment; 
           [0010]      FIG. 2  is a perspective view of the vessel tray clamp of  FIG. 1  in accordance with an exemplary embodiment; 
           [0011]      FIGS. 3 and 4  are cross-sectional views of a vessel tray clamp during and after installation in a vessel for securing a vessel tray to vessel support structure in accordance with an exemplary embodiment; 
           [0012]      FIG. 5  is a perspective view of an alternate vessel tray clamp in accordance with an exemplary embodiment; 
           [0013]      FIG. 6  is a side view of the vessel tray clamp of  FIG. 5  shown engaging a tray; and 
           [0014]      FIG. 7  is an end view of the vessel tray clamp of  FIG. 5  shown engaging a tray. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    The following detailed description of the invention is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. Furthermore, there is no intention to be bound by any theory presented in the preceding background of the invention or the following detailed description of the invention. 
         [0016]    Various exemplary embodiments contemplated herein are directed to clamps for securing trays to a support structure in a vessel. The clamps are configured for easy installation in the vessel, and for fewer clamps per tray. Specifically, an increased compression force exhibited by the clamps herein allows for a reduced number of clamps per tray. 
         [0017]    An exemplary vessel  10  is illustrated in  FIG. 1 . vessel  10  can be any suitable vessel, for example, a hydroprocessing vessel, a reactor, an absorber, a stripper, a distillation column, or the like. Generally, such a vessel  10  facilitates mass transfer operations in a flow orientation, such as downflow, upflow, co-current flow, and counter-current flow for one or more fluid including a vapor, a liquid, and/or a mixed-phase of vapor and liquid. As shown, vessel  10  includes vapor and/or liquid mixing, contacting, collecting, and/or redistributing tray  12 . While only one tray  12  is shown for illustrative purposes, it will be appreciated that vessel  10  can have any number of trays suitable for a particular application. As shown, tray  12  rests on, and is typically secured to, support structure  16 . Usually, tray  12  has several openings for permitting the passage of fluid there-through, such as allowing liquid to flow downward and gas to rise upwards to facilitate mass transfer operations. Tray  12  can include other structures, such as bubble caps, tray valves, downcomers, and weirs to facilitate desired operations. 
         [0018]    In  FIG. 1 , vessel  10  forms an enclosure  14  provided with an internal support structure  16  which includes a support ring  18  and/or one or more beams  20 . As shown, clamps  22  are used to secure tray  12  to support structure  16 , such as support ring  18  or support beams  20  that may underlie tray  12 . Typically, support ring  18  encircles the internal volume of the vessel  10  and is secured by any suitable means, such as welding, to the walls of enclosure  14 . Beams  20  can also be coupled to the walls of enclosure  14 , using any suitable means, such as welding. 
         [0019]    An exemplary embodiment of clamp  22  is illustrated in  FIG. 2 . Clamp  22  is generally S-shaped and includes a midline  24  that defines a longitudinal plane  26 . Clamp  22  has a distal end  28 , an intermediate portion  30 , and a proximate end  32 . As shown, intermediate portion  30  is arcuate while distal end  28  and proximate end  32  are substantially planar and parallel. Depending on the desired use, distal end  28  may be arcuate or planar and non-parallel to proximate end  32 . As shown, distal end  28  and intermediate portion  30  have a width  34 . Further, clamp  22  is formed with a shoulder  36  that has a shoulder width  38 . Shoulder width  38  is greater than width  34 . Clamp  22  is also formed with an elongated opening  40  that has a longitudinal axis  42  coincident with midline  24 . In  FIG. 2 , elongated opening  40  is completely bound by clamp  22 . 
         [0020]    Clamp  22  is preferably made of stainless steel, and most preferably stainless steel 321 and stainless steel 347. Grades 321 and 347 are the basic austenitic 18/8 steel stabilized by titanium (321) or niobium (347) additions. These grades are used because they are not sensitive to intergranular corrosion after heating within the carbide precipitation range of 425-850° C. Grade 321 is the grade of choice for applications in the temperature range of up to about 900° C., combining high strength, resistance to scaling and phase stability with resistance to subsequent aqueous corrosion. A limitation with 321 is that titanium does not transfer well across a high temperature arc, so is not recommended as a welding consumable. In this case grade 347 is preferred—the niobium performs the same carbide stabilization task but can be transferred across a welding arc. Grades, 321 and 347 have excellent forming characteristics, are readily brake or roll formed and have outstanding welding characteristics. Post-weld annealing is not required. They also have excellent toughness, even down to cryogenic temperatures. For installation in vessels having less severe conditions, lower grade materials such as Killed Carbon Steel may be used for the clamps. Regardless of the specific material used, during fabrication of clamps  22 , the clamp  22  is typically stamped from a standard 6 mm thick plate. The shoulders  36  and elongated opening  40  are then cut and the material is bent into the desired S-shape. 
         [0021]    As may be seen in reference to  FIG. 3 , clamp  22  is designed for facilitating installation and engagement with tray  12  and support structure  16  (i.e., support ring  18 ). In  FIG. 3 , tray  12  includes an edge  50 , a slot  52  located proximate to edge  50 , an upper surface  54 , a lower surface  56  resting on support structure  16 , a hole  58 , and optionally a nut  60  aligned with hole  58  and tack welded to lower surface  56 . Tray  12  may be circular, with a tangent line at  61 . Support structure  16  includes a topside  62  and an underside  64 . Also, a gasket or seal blanket  66  is positioned at the interface  68  between tray  12  and support structure  16 . 
         [0022]    With this understanding of the structure of tray  12 , support structure  16 , and clamp  22 , installation of clamp  22  may be considered. As shown in an initial position  70  in  FIG. 3 , distal end  28  of clamp  22  is inserted into and passed through slot  52  in tray  12  in the direction of arrow  72 . As intermediate portion  30  reaches slot  52 , translational movement of clamp  22  continues in the direction of arrow  72 , while clamp  22  is also pivoted in the direction of arrow  74  about slot axis or intersecting line  76 . It is noted that the alignment and tight fit between the slot  52  and the distal end  28  of the clamp  22  limits both translational and pivotable movement of the clamp  22  to within the longitudinal plane  26  (the plane of the drawing page in  FIG. 3 ). Movement of clamp  22  in the direction of arrows  72  and  74  continues until clamp  22  reaches a stationary position  78  when shoulder  36  abuts upper surface  54  of tray  12 . In stationary position  78 , in addition to the contact between shoulder  36  and tray  12 , distal end  28  of clamp  22  contacts underside  64  of support structure  16 . Further, slot  52  and clamp  22  are sized to allow insertion of clamp  22  but to prevent substantially any pivotable movement of clamp  22  other than about slot axis  76 . 
         [0023]    As shown in  FIG. 4 , upon reaching stationary position  78 , a fastener  80 , such as a threaded bolt or other known fasteners, may be passed through elongated opening  40  in clamp  22  and through hole  58  and nut  60  in tray  12 . The length of elongate opening  40  facilitates the alignment fastener  80  with hole  58  regardless of differing distances between the support structure  16  and hole  58 . Further, when passing fastener  80  through elongated opening  40 , the necessary downward pressure of the action on proximate end  32  of clamp  22  further holds clamp  22  in stationary position  78  and reduces or eliminates slippage or unwanted movement of clamp  22  during installation. 
         [0024]    After fastener  80  is engaged with clamp  22  and tray  12 , it may be selectably tightened with an engagement force in the direction of arrows  82  to reduce the distance  84  therebetween. As distance  84  is decreased, a compressive force in the direction of arrows  86  is exerted onto support structure  16  (and gasket  66 ). With the levering action of clamp  22 , the engagement force  82  of fastener  80  is multiplied by a factor dependent on the location of the fulcrum (slot axis  76 ) and length of clamp  22  to exert compressive force  86 , which may be optimized to provide a desired compressive force  86  depending on the anticipated operations in vessel  10 . In any event, compressive force  86  exhibited by clamp  22  is substantially increased over current tray clamps in commercial use. 
         [0025]    Referring now to  FIGS. 5-7 , an alternate embodiment of the vessel tray clamp  22  is shown. It is noted that the view of  FIG. 6  is taken along line  6 - 6  in  FIG. 5 , and the view of  FIG. 7  is taken along line  7 - 7  in  FIG. 5 . In  FIGS. 5-7 , tray  12  includes a stud or projection  90  that extends upward from and substantially perpendicular to the upper surface  54  of tray  12 . Preferably, projection  90  is steel and is welded to the upper surface  54  of tray  12 . Projection  90  is formed with a vertically-extending aperture  92 . As shown in  FIGS. 5-7 , clamp  22  includes a distal edge  94  that forms elongated opening  40 . In other words, elongated opening  40  is not completely bounded by clamp  22 . As a result, clamp  22  may be positioned and slidingly engaged with projection  90 . After clamp  22  is brought to stationary position  78 , a fastener  80  such as a wedge pin is forced into aperture  92 , exerting an engagement force on clamp  22 . Specifically, fastener  80  includes a sloping surface  96  that contacts projection  90  to exert the downward engagement force as fastener  80  is driven into aperture  92 . 
         [0026]    As may be imagined, there are a number of methods known in the art for engaging the proximate end of the clamp with the tray. While two specific types of fasteners are illustrated and discussed herein, other fasteners and reciprocating proximate end and tray designs are contemplated herein. 
         [0027]    Accordingly, a vessel tray clamp for securing a tray to a support structure in a vessel has been provided. From the foregoing, it is to be appreciated that the exemplary embodiments of the vessel tray clamp facilitate installation by limiting the clamp to a single orientation for installation, by limiting movement of the clamp to within a single plane during installation, and by holding the clamp in a stationary position during fastening of the clamp to the tray. Further, the vessel tray clamp exerts a substantially increased compression force to secure the seal between the tray and support structure. 
         [0028]    While at least one exemplary embodiment has been presented in the foregoing detailed description of the invention, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the invention, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims and their legal equivalents.