Patent Publication Number: US-2017370470-A1

Title: Fluid conveyance system gasket assembly and methods of assembling the same

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims priority to U.S. Provisional Patent Application No. 62/098,027 filed on 30 Dec. 2015, the entire disclosure of which is hereby incorporated by reference in its entirety. 
    
    
     FIELD 
     The field of the disclosure relates generally to systems and methods for providing a seal within a fluid conveyance system and, more particularly, to systems and methods for preventing particle entry into a fluid flow channel. 
     BACKGROUND 
     Many conventional fluid conveyance systems include channeling a fluid through two or more sections of a conduit. For example, a fluidized bed reactor (FBR) is a type of fluid conveyance system that can be used to carry out a variety of multiphase chemical reactions. In this type of reactor, a fluid (gas or liquid) is passed through a conduit and into a chamber that contains a granular solid material (usually a catalyst possibly shaped as tiny spheres) at high enough velocities to suspend the solid and cause it to behave as though it were a fluid. 
     Because FBRs channel the fluid at a high velocity, a robust seal is required between adjacent portions of the conduit through which the fluid is being channeled. Traditionally, standard metallic ring type joint (RTJ) gaskets are used in such high pressure service. RTJ gaskets seal by creating a metal on metal seal between the gasket and opposing flanges of the adjacent conduits. The RTJ gaskets are chosen such that the gasket material is softer than the flange face so that when it seats, the gasket is embedded in the flanges. 
     In many higher flange classes (class 600 and above) the bolts that connect the flanges have enough strength to properly seat the metallic RTJ gasket. However, in lower flange classes, such as classes 150 and 300, the bolts may not have enough strength to properly seat the gaskets. 
     Furthermore, some RTJ gaskets have the potential to shed particulates from the facing materials of the gasket when it is being seated. These particles may travel to the flow channel and become entrained in the fluid flowing therethrough and contaminate the desired reaction. 
     Accordingly, a need exists for a gasket that has a lower seating stress to enable the gasket to be properly seated and also that prevents entrainment of gasket particles in the fluid flow. 
     This Background section is intended to introduce the reader to various aspects of art that may be related to various aspects of the present disclosure, which are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present disclosure. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art. 
     BRIEF SUMMARY 
     A gasket assembly for use in a fluid conveyance system is provided. The gasket assembly includes a first ring circumscribing a flow channel and comprising an inner surface having a notch formed therein. The gasket assembly also includes a dust shield at least partially inserted into the notch. The dust shield is positioned between the first ring and the flow channel to prevent particulates of the first ring from entering the flow channel. 
     A fluid conveyance system for channeling a fluid through a flow channel is provided. The fluid conveyance system includes a first conduit comprising a first flange, a second conduit comprising a second flange, and a gasket assembly positioned between the first and second flange to form a seal therebetween. The gasket assembly includes an outer ring comprising a radially inner surface having a notch formed therein and a dust shield at least partially inserted into the notch. The dust shield is positioned between the outer ring and the flow channel to prevent particulates of the outer ring from entering the flow channel. 
     A method of assembling a fluid conveyance system includes providing a first ring having a notch formed therein, wherein the first ring circumscribes a flow channel. A second ring is then at least partially inserted into the notch. The method also includes attaching a third ring to the second ring such that the second ring spaces the first ring from the third ring. The third ring is positioned between the first ring and the flow channel to prevent particulates of the first ring from entering the flow channel. 
     Various refinements exist of the features noted in relation to the above-mentioned aspects. Further features may also be incorporated in the above-mentioned aspects as well. These refinements and additional features may exist individually or in any combination. For instance, various features discussed below in relation to any of the illustrated embodiments may be incorporated into any of the above-described aspects, alone or in any combination. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is cross-section of a fluid conveyance system including an embodiment of a gasket assembly; 
         FIG. 2  is a top plan view of the gasket assembly of  FIG. 1 ; 
         FIG. 3  is a cross-section of an outer ring of the gasket assembly taken along line  3 - 3  in  FIG. 2 ; 
         FIG. 4  is a top plan view of an intermediate ring of the gasket assembly of  FIG. 2 ; 
         FIG. 5  is a top plan view of an inner ring of the gasket assembly of  FIG. 2 ; and 
         FIG. 6  is a cross-section of a portion of the fluid conveyance system taken along line  6 - 6  in  FIG. 2 . 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views of the drawings. 
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , a fluid conveyance system is shown and is indicated generally at  100 . The fluid conveyance system  100  is used to channel a flow of fluid  102  through a flow channel  104  to desired destination. In one embodiment, the fluid conveyance system  100  is a portion of a fluidized bed reactor. More specifically, fluid conveyance system  100  is used in a high purity gas service on a gas inlet of the fluidized bed reactor. In another suitable embodiment, the fluid conveyance system  100  is a portion of any system that facilitates operation of the fluid conveyance system  100  as described herein. 
     The illustrated fluid conveyance system  100  includes a first conduit  106  connected to a second conduit  108 . More specifically, the first conduit  106  includes a first flange  110  that is connected to a second flange  112  of the second conduit  108 . When the fluid conveyance system is assembled, the first and second conduits  106  and  108  define the flow channel  104  therethrough. Furthermore, the first flange  110  includes a first surface  114  that is oriented opposite a second surface  116  of the second flange  112 . The flanges  110  and  112  are connected to each other using a fastener  118  inserted through openings defined in each of the flanges  110  and  112 . 
     The first flange  110  also includes a first groove  120  defined therein. The first groove  120  includes a pair of obliquely-oriented walls  122 , each of which includes an engaging surface  124 . Each engaging surface  124  includes a plurality of grooves, ridges, or teeth, as described in further detail below. Similarly, the second flange  112  includes a second groove  126  defined therein. The second groove  126  includes a pair of obliquely-oriented walls  128 , each of which include an engaging surface  130  that includes a plurality of grooves, ridges, or teeth, as described in further detail below. The first and second grooves  120  and  126  are aligned such that the grooves  120  and  126  define a cavity  132  therebetween. 
     The fluid conveyance system  100  also includes a gasket assembly  200  positioned within the cavity  132  such that the first and second surfaces  114  and  116  are spaced apart by a gap  134 . The gasket assembly  200  includes an outer ring  202 , a plurality of sealing strips  204 , and a dust shield  206 . Both the plurality of sealing strips  204  and the dust shield are attached to the outer ring  202 . More specifically, the dust shield  206  includes an intermediate ring  208  attached to the outer ring  202  and an inner ring  210  attached to the intermediate ring  208 . 
     The gasket assembly  200  is configured to provide a seal between the flanges  110  and  112  of the conduits  106  and  108  to prevent the fluid  102  within the flow channel  104  from escaping between flanges  110  and  112 . More specifically, the outer ring  202  provides the fluid sealing between flanges  110  and  112  and the dust shield  206  provides for a particle seal between the outer ring  202  and the flow channel  104 . More specifically, the dust shield  206 , and therefore the intermediate ring  208  and the inner ring  210 , are positioned within the gap  134  between the flanges  110  and  112  to prevent any particles from the outer ring  202  and/or the sealing strips  204  from entering the flow channel  104  and contaminating the fluid  102  flowing therethrough. 
       FIG. 2  shows a top plan view of the gasket assembly  200  including the outer ring  202  and the dust shield  206 . As described above, the dust shield  206  includes the intermediate ring  208  and the inner ring  210 . 
       FIG. 3  is a cross-section of the outer ring  202  of the gasket assembly  200  taken along line  3 - 3  in  FIG. 2 . In one embodiment, the outer ring  202  is an octagonal Kammprofile ring joint gasket. In other suitable embodiments, the outer ring  202  is any type of ringed gasket seal that facilitates operation of the fluid conveyance system as described herein. The outer ring  202  includes a plurality of obliquely-oriented engaging surfaces  212  that each includes a plurality of grooves or ridges  214  formed thereon. The sealing strips  204  are attached to the outer ring  202  at a respective engaging surface  212  such that each sealing strip  204  is positioned on the plurality of grooves  214  of a respective engaging surface  214 . 
     In one embodiment, the outer ring  202  is formed from a metallic material, such as, but not limited to, stainless steel, nickel-chromium alloy, and chromium-steel alloy. More specifically, the outer ring  202  is formed from a metallic material such that the outer ring  202  includes a seating stress within a range of between approximately 2,500 pounds per square inch (psi) and approximately 5,000 psi. In another suitable embodiment, the outer ring  202  may have any seating stress that enables operation of the fluid conveyance system as described herein. Furthermore, the plurality of sealing strips  204  are formed from a metallic material that is softer than the materials of the outer ring  202  and the flanges  110  and  112 . More specifically, the plurality of sealing strips  204  are formed from a material such as, but not limited to, graphite, exfoliated vermiculite, mica, or polytetrafluoroethylene. 
     The outer ring  202  also includes an inner surface  216  that includes a notch  218  defined therein. As described in further detail below, the notch  218  is configured to receive at least a portion of the dust shield  206  therein. 
       FIG. 4  is a top plan view of the intermediate ring  208  of the gasket assembly  200 . The intermediate ring  208  includes an inner edge  220 , an outer edge  222 , and a width W 1  defined therebetween. In one embodiment, the intermediate ring  208  is C-shaped and includes a first end  224 , a second end  226 , and a gap  228  defined therebetween. The C-shape of intermediate ring  208  facilitates moving the ends  224  and  226  independently of each other to increase the ease of assembly of the gasket assembly  200 . In another suitable embodiment, the intermediate ring  208  is a continuous ring and does not include the gap  228 . As described herein, the outer edge  222  of the intermediate ring  208  is inserted into the notch  218  defined in the outer ring  202  to attach the dust shield  206  to the outer ring  202 . 
     In one embodiment, the intermediate ring  208 , and therefore, the dust shield  206 , is free to float within the notch  218  and is not positively attached to the outer ring  202  by any mechanical or bonding means. In another suitable embodiment, the intermediate ring  208  is positively attached to the outer ring  202  within the notch  218 . In one embodiment, the intermediate ring  208  is a substantially flat ring formed from a metallic material, such as, but not limited to stainless steel. In another suitable embodiment, the intermediate ring  208  is formed from any material that facilitates operation of the fluid conveyance system as described herein. 
       FIG. 5  is a top plan view of the inner ring  210  of the gasket assembly  200 . The inner ring  210  is a substantially hollow crushable tube ring that includes a radially inner surface  230  and a radially outer surface  232 . In one embodiment, the radially outer surface  232  is attached to the radially inner edge  220  of the intermediate ring  208  by tack welding. In another suitable embodiment, the inner ring  210  is attached to the intermediate ring  208  by any means that enables operation of the fluid conveyance system described herein. 
     The inner ring  210  also includes a pair of vent holes  234  formed therein. More specifically, the vent holes  234  are formed at opposite points of the inner ring with respect to one another. That is, the vent holes  234  are formed 180 degrees apart from one another. The vent holes  234  are configured to prevent a pressure differential from developing across the inner ring  210  when it is installed between the flanges  110  and  112 . More specifically, the vent holes  232  prevent a pressure differential between the flow channel side of the inner ring  210  and the space defined between the inner ring  210  and the outer ring  202 . Moreover, the vent holes  232  are formed 180 degrees apart to maximize the distance that a particle, from the outer ring  202  and/or the sealing strips  204 , within the inner ring  210  would have to travel in order to escape the inner ring  210  and mix with the fluid  102  within the flow channel  104  (this may be termed a “tortuous path”). 
     In one embodiment, the inner ring  210  is formed from a metallic material, such as but not limited to stainless steel. In another suitable embodiment, the inner ring  210  is formed from any material that facilitates operation of the fluid conveyance system  100  as described herein. More specifically, the inner ring  210  is formed from any material that deforms when the first and second flanges  110  and  112  are tightened together. 
       FIG. 6  is a cross-section of a portion of the fluid conveyance system  100  taken along line  6 - 6  in  FIG. 2 . As shown in  FIG. 6 , the inner ring  210  includes a diameter D that is substantially similar to a width W 2  of the gap  134  between flange surfaces  114  and  116 . In another suitable embodiment, the inner ring  210  includes a diameter that is slightly less than or slightly greater than the width of the gap  134 . As such, the inner ring  210  spans the gap  134  and extends the full distance between the flange surfaces  114  and  116  when the fluid conveyance system is assembled. 
     In operation, the outer ring  202  is positioned within the second groove  126  such that the sealing strips  204  are positioned between the ridges  214  of the outer ring  202  and the engaging surface  124  of the second groove  126 . The dust shield  206  is assembled by attaching the inner edge  220  of the intermediate ring  208  to the outer surface  232  of the inner ring  210 . The dust shield is then seated within the notch  218  defined in the inner surface  216  of the outer ring  202 . The intermediate ring  208  includes a thickness T that is slightly less than a width W 3  of the notch  218  such that the outer edge  222  of the intermediate ring is partially inserted into the notch  218 . As described above, in one embodiment, the dust shield  206  is not positively fastened to the outer ring  202  by any means. 
     Once the dust shield  206  is in place, the first conduit  106  is positioned such that the first groove  120  receives a portion of the outer ring  202 . More specifically, similar to the second groove  126 , the outer ring  202  is positioned within the first groove  120  such that the sealing strips  204  are positioned between the ridges  214  of the outer ring  202  and the engaging surface  124  of the first groove  120 . 
     In such a configuration, as shown in  FIG. 6 , the dust shield  206  is positioned in the gap  134  between the opposing flange surfaces  114  and  116  such that the inner ring  210  spans the width W 2  of the gap  134 . 
     The fastener  118  is then threaded through the flanges  110  and  112  and tightened. Tightening of the fastener  118  causes the ridges of the flange engaging surfaces  124  (in the grooves  120  and  126 ) to engage the sealing strips  204 . More specifically, the sealing strips  204  are compressed between the engaging surfaces  124  and the ridges  214  of the outer ring engaging surfaces  212 . Compression of the sealing strips  204  creates the seal that prevents the fluid  102  from escaping the flow channel  104  and being exposed to the outside environment. 
     During tightening, it is possible that particles from the sealing strips  204  or the flanges  110  and  112  may be fragmented when the sealing strips  204  are crushed and be introduced to the gap  134 . The dust shield  206  is configured to prevent those particles from traveling to the flow channel  104  and becoming entrained with the fluid  102  therein. 
     As the conduits  106  and  108  are connected and tightened together, the width W 2  of the gap  134  between flange surfaces  114  and  116  to decrease, which, in turn, causes a compression deformation of the inner ring  210 . Therefore, the inner ring  210  creates a seal between flange surfaces  114  and  116  and seals the gap  134 . In such a configuration, the flow channel side of the inner ring  210  is sealed from the gasket side to prevent any particulates from the outer ring  202 , the sealing strips  204 , or the flanges  110  and  112  that are created during tightening from entering the flow channel  104 . 
     As described above, the vent holes  232  are formed in the inner ring  210  to prevent a pressure differential between the flow channel side and the gasket side of the inner ring  210 . The vent holes  232  equalize the pressure across the inner ring  210 . Further, the vent holes  232  are drilled 180 degrees apart from one another such that if any particles enter the inner ring  210  through one vent hole  232 , then the particle must travel a maximum distance around the circumference of the inner ring  210  to the other vent hole  232  to escape the inner ring  210 . 
     The fluid conveyance system and gasket assembly of the present disclosure provide an improvement over known fluid conveyance systems and gasket assemblies. The gasket assembly of the present disclosure has a lower seating stress than known gasket assemblies, and also maintains purity levels of a fluid flow by sealing the main gasket body from the flow channel. 
     More specifically, the gasket assembly described herein includes a dust shield that prevents particles fragmented from other components of the fluid conveyance system from being entrained with the fluid flowing within the flow channel. The dust shield includes a centering intermediate ring and a crushable tubing inner ring. The intermediate ring is inserted into a notch formed in the outer ring and spaces the inner ring from the outer ring. The inner ring is positioned between opposing surfaces of adjacent conduits such that when the conduits are fastened together, the inner ring is deformed and forms a seal between the outer ring and the flow channel. 
     When introducing elements of the present invention or the embodiment(s) thereof, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of the elements. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements. 
     As various changes could be made in the above constructions and methods without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.