Patent Publication Number: US-2022235687-A1

Title: Retention appartus for wire mesh arrangement

Description:
This application is being filed on May 8, 2020, as a PCT International Patent application and claims the benefit of priority to U.S. Provisional patent application Ser. No. 62/846,197, filed May 10, 2019, the entire disclosure of which is incorporated by reference in its entirety. 
    
    
     BACKGROUND 
     Vehicles equipped with diesel engines typically include exhaust systems that have aftertreatment systems such as selective catalytic reduction catalyst devices, lean NOx catalyst devices, or lean NOx trap devices to reduce the amount of undesirable gases, such as nitrogen oxides (NOx) from the exhaust. In order for these types of aftertreatment devices to work properly, a doser injects reactants, such as urea, ammonia, or hydrocarbons, into the exhaust gas. As the exhaust gas and reactants flow through the aftertreatment device, the exhaust gas and reactants convert the undesirable gases, such as NOx, into more acceptable gases, such as nitrogen and oxygen. However, the efficiency of the aftertreatment system depends upon how evenly the reactants are mixed with the exhaust gases. Therefore, there is a need for a flow device that provides a uniform mixture of exhaust gases and reactants. 
     A wire mesh puck can be disposed opposite or second of the doser to aid in dispersing the reactant within the exhaust flow. The wire mesh puck is spot welded and brazed into a mantle (i.e., a surrounding support ring). Accordingly, the peripheral side of the wire mesh puck is mechanically attached to the mantle at one or more points. The mantle is then attached within a conduit (e.g., by welding). Improvements are desired. 
     SUMMARY 
     Some aspects of the disclosure are directed to a retention assembly and method for a wire mesh puck for use with an exhaust after treatment device. The wire mesh puck is axially retained within a conduit by a retaining arrangement. The retaining arrangement supports the mesh puck about a peripheral area of the end faces of the mesh puck. A peripheral side of the wire mesh puck is allowed to float relative to an interior surface of the conduit. Advantageously, allowing the peripheral side of the mesh puck to float may reduce the stress applied to the mesh puck under vibrating conditions. 
     In certain implementations, the wire mesh puck is axially retained while in an axially compressed state (i.e., is under axial compression). In some examples, the axial compression is sufficient to inhibit rotation of the wire mesh puck. 
     In other examples, a secondary mechanism can be used to inhibit rotation of the mesh puck. For example, one or more dimples may inhibit rotation by extending into the peripheral edge of the mesh puck without being affixed to the peripheral edge. 
     In some implementations, the mesh puck is mantle-less. In such examples, the retention arrangement is formed by one or more components of the exhaust aftertreatment device. Removing the mantle may reduce the cost of the system by reducing the number of parts therein and/or by eliminating the labor to attach the puck to the mantle. In other implementations, a mantle defines the conduit and carries the mesh puck within the conduit. The mantle can be mechanically coupled to one or more components of the exhaust aftertreatment device. 
     In certain implementations, the retaining arrangement includes at least a first stop member and a second stop member. In certain examples, the retaining arrangement includes a plurality of first stop members. In certain examples, the retaining arrangement includes a plurality of second stop members. In some examples, the first stop member is integral with the conduit (e.g., is formed by beading, dimpling, tapering, and/or crimping the conduit). In other examples, the first stop member is a separate piece that is mechanically coupled (e.g., welded, riveted, fastened, adhesively affixed, etc.) within the conduit. 
     A variety of additional inventive aspects will be set forth in the description that follows. The inventive aspects can relate to individual features and to combinations of features. It is to be understood that both the forgoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the broad inventive concepts upon which the embodiments disclosed herein are based. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of the description, illustrate several aspects of the present disclosure. A brief description of the drawings is as follows: 
         FIG. 1  is a cross-sectional view of a first example retention arrangement holding a mesh puck within a conduit; 
         FIG. 2  is a cross-sectional view of a second example retention arrangement holding a mesh puck within a conduit; 
         FIG. 3  is a cross-sectional view of a third example retention arrangement holding a mesh puck within a conduit; 
         FIG. 4  is a cross-sectional view of a fourth example retention arrangement holding a mesh puck within a conduit; 
         FIG. 5  is a cross-sectional view of a fifth example retention arrangement holding a mesh puck within a conduit; 
         FIG. 6  is a cross-sectional view of a sixth example retention arrangement holding a mesh puck within a conduit; 
         FIG. 7  is a front elevational view of an example mesh puck suitable for use with any of the retention arrangements disclosed herein; 
         FIG. 8  is a cross-sectional view of an example exhaust treatment device including a dosing and mixing assembly configured to utilize the mesh puck and any of the retention arrangements disclosed herein, the retention arrangement shown including first and second stop members disposed on telescoping pipes; 
         FIG. 9  is an enlarged view of a portion of  FIG. 8 ; 
         FIG. 10  is a front elevational view of a seventh example retention arrangement holding a mesh puck within a conduit; 
         FIG. 11  is a cross-sectional view of an example exhaust treatment device including a dosing and mixing assembly configured to utilize the mesh puck and any of the retention arrangements disclosed herein, the retention arrangement shown including first and second stop members disposed on telescoping pipes; and 
         FIG. 12  is an enlarged view of a portion of  FIG. 11 . 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to exemplary aspects of the present disclosure that are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. 
     The present disclosure is directed to an exhaust treatment device coupled to an exhaust pipe. The exhaust treatment device including a mesh puck held by a retention arrangement. The mesh puck includes opposite first and second axial ends separated by a peripheral side. The retention arrangement maintains the mesh puck in an axially compressed state while allowing the peripheral side of the mesh puck to float relative to the interiorly facing surface of a surrounding conduit. As the term is used herein, the peripheral side “floats” when the portions of the wires forming the peripheral side are not mechanically connected to the opposing surface of a surrounding conduit. In some examples, the retention arrangement applies an axial compression force on portions of the end faces of the mesh puck. In other examples, the axial compression force is applied separate from the retention arrangement. 
     In some examples, the mesh puck is a mantle-less mesh puck. In such examples, the retention arrangement is disposed within an exhaust flow conduit of the exhaust treatment device without an intervening structure (see  FIGS. 1-6 ). In other examples, the mesh puck has a mantle. In such examples, the mantle defines the conduit in which the retention arrangement is disposed. The mantle would define the retention arrangement to axially compress the mesh puck  110  while allowing the peripheral edge to float relative to the mantle. The mantle could then be mechanically connected (e.g., welded) within an exhaust flow conduit of the exhaust treatment device. 
     Referring to the figures in general, example retention arrangements  100 ,  120 ,  130 ,  140 ,  150 ,  160 ,  230 ,  260  for axially retaining a mesh puck  110  within a conduit  102 ,  122 ,  132 ,  142 ,  212 ,  220  through which exhaust flows (see arrow E) are shown. The retention arrangement  100 ,  120 ,  130 ,  140 ,  150 ,  160 ,  230 ,  260  includes first and second stop members  106 ,  156 ,  226 ,  270 ,  108 ,  128 ,  138 ,  148 ,  168 ,  178 ,  188 ,  264 . The mesh puck  110  is trapped between the first stop member  106 ,  156 ,  226 ,  270  and the second stop member  108 ,  128 ,  138 ,  148 ,  168 ,  178 ,  188 ,  264  to inhibit axial movement of the mesh puck  110  along a longitudinal axis L of the conduit  102 . In some implementations, the first stop member  106 ,  226 ,  270  is disposed upstream of the mesh puck  110  and the second stop member  108 ,  128 ,  138 ,  148 ,  168 ,  178 ,  188 ,  264  is disposed downstream of the mesh puck  110 . In other implementations, the first stop member  106 ,  226 ,  270  is disposed downstream of the mesh puck  110  and the second stop member  108 ,  128 ,  138 ,  148 ,  168 ,  178 ,  188 ,  264  is disposed upstream of the mesh puck  110 . 
     As shown in  FIG. 7 , the mesh puck  110  has a first axial end face  112 , an opposite second axial end face  114 , and an outwardly-facing periphery  116  extending between the first and second faces  112 ,  114 . The mesh puck  110  has a cross-dimension (e.g., diameter if the puck is circular) D extending parallel with the faces  112 ,  114  and a thickness extending along a mesh axis M between the first and second axial end faces  112 ,  114 . In certain examples, the mesh puck  110  is formed from a knit tube of wires, which is flattened, crimped, rolled into a puck, cleaned, and brazed. 
     In certain implementations, the mesh puck  110  is resilient at least along the mesh axis M. In certain examples, the mesh puck  110  is installed within the conduit  102 ,  122 ,  132 ,  142 ,  212 ,  220  in an axially compressed state. In some examples, the mesh puck  110  is axially compressed by the first and second stop members. In other examples, the compression force is separately applied to the mesh puck  110  and the first and second stop members inhibit the mesh puck  110  from returning to an uncompressed state. 
     In certain implementations, the mesh puck  110  is axially compressed by an axial compression distance of at least 0.01 inches when in the axially compressed state compared to an uncompressed state. In certain implementations, the axial compression distance is at least 0.02 inches. In certain implementations, the axial compression distance is at least 0.03 inches. In certain implementations, the axial compression distance is at least 0.04 inches. In certain implementations, the axial compression distance is at least 0.05 inches. In certain implementations, the axial compression distance is at least 0.06 inches. In certain implementations, the axial compression distance is at least 0.07 inches. In certain implementations, the axial compression distance is at least 0.08 inches. In certain implementations, the axial compression distance is at least 0.09 inches. In certain implementations, the axial compression distance is at least 0.1 inches. 
     In certain implementations, the compression force is applied to opposite first and second axial end faces  112 ,  114  of the mesh puck  110 . In certain examples, the mesh puck  110  is axially compressed using at least 1 pound-force. In certain examples, the mesh puck  110  is axially compressed using at least 5 pound-force. In certain examples, the mesh puck  110  is axially compressed using at least 20 pound-force. In certain examples, the mesh puck  110  is axially compressed using at least 50 pound-force. In certain examples, the mesh puck  110  is axially compressed using at least 80 pound-force. In certain examples, the mesh puck  110  is axially compressed using at least 100 pound-force. 
     In certain implementations, the retention arrangement  100 ,  120 ,  130 ,  140 ,  150 ,  160 ,  230 ,  260  applies or maintains a compression force of at least 50 pound-force to the mesh puck  110 . In certain implementations, the retention arrangement  100 ,  120 ,  130 ,  140 ,  150 ,  160 ,  230 ,  260  applies or maintains a compression force of between about 75 pound-force and 125 pound-force to the mesh puck  110 . In certain implementations, the retention arrangement  100 ,  120 ,  130 ,  140 ,  150 ,  160 ,  230 ,  260  applies or maintains a compression force of between about 85 pound-force and 100 pound-force to the mesh puck  110 . In certain examples, the retention arrangement  100 ,  120 ,  130 ,  140 ,  150 ,  160 ,  230 ,  260  applies or maintains a compression force of about 85 pound-force. In certain examples, the retention arrangement  100 ,  120 ,  130 ,  140 ,  150 ,  160 ,  230 ,  260  applies or maintains a compression force of about 90 pound-force. In certain examples, the retention arrangement  100 ,  120 ,  130 ,  140 ,  150 ,  160 ,  230 ,  260  applies or maintains a compression force of about 95 pound-force. In certain examples, the retention arrangement  100 ,  120 ,  130 ,  140 ,  150 ,  160 ,  230 ,  260  applies or maintains a compression force of about 100 pound-force. 
     In some implementations, the outwardly-facing periphery  116  of the mesh puck  110  does not contact the interiorly facing surface  104  of the conduit  102 ,  122 ,  132 ,  142 ,  212 ,  220 . In other implementations, the interiorly facing surface  104  applies radial pressure on the periphery  116  of the mesh puck  110 . In certain implementations, the periphery  116  is allowed to float relative to the interiorly facing surface  104  of the conduit  102 ,  122 ,  132 ,  142 ,  212 ,  220 . As the term is used herein, the periphery “floats” when no portion of the outwardly-facing periphery  116  is mechanically attached (e.g., welded, glued, brazed, etc.) to the interiorly facing surface  104 . 
     In certain implementations, the first and second stop members  106 ,  226 ,  270 ,  108 ,  128 ,  138 ,  148 ,  178 ,  188 ,  264  extend across only a portion of the end faces  112 ,  114 . In certain implementations, a majority of the surface area of the end faces  112 ,  114  remains exposed to exhaust flow when the mesh puck  110  is being axially compressed by the first and second stop members  106 ,  226 ,  270 ,  108 ,  128 ,  138 ,  148 ,  168 ,  178 ,  188 ,  264 . In certain implementations, the first and second stop members  106 ,  226 ,  270 ,  108 ,  128 ,  138 ,  148 ,  178 ,  188 ,  264  extend over only an outermost periphery of the end faces  112 ,  114 . 
     In some implementations, each of the first and second stop members  106 ,  226 ,  270 ,  108 ,  128 ,  138 ,  148 ,  168 ,  178 ,  188 ,  264  can form a continuous support ring around a circumference of the interiorly facing surface  104  of the conduit  102 ,  122 ,  132 ,  142 ,  212 ,  220 . In various examples, the continuous support ring can include a separate ring sized to be fitted within the conduit  102 ,  122 ,  132 ,  142 ,  212 ,  220 , an integral ring extending into the conduit  102 ,  122 ,  132 ,  142 ,  212 ,  220  from the interiorly facing surface  104 , or a crimped, beaded, or dimpled portion of the interiorly facing surface  104  of the conduit  102 ,  122 ,  132 ,  142 ,  212 ,  220 . In other implementations, each of the first and second stop members  106 ,  226 ,  270 ,  108 ,  128 ,  138 ,  148 ,  168 ,  178 ,  188 ,  264  can form an interrupted support ring around the circumference of the interiorly facing surface  104  of the conduit  102 ,  122 ,  132 ,  142 ,  212 ,  220 . In various examples, the interrupted support ring can include a circumferential pattern of welded beads protruding into the conduit  102 ,  122 ,  132 ,  142 ,  212 ,  220 , a series of circumferentially spaced dimpled portion, cut portions, beaded portions, or crimped portions of the conduit  102 ,  122 ,  132 ,  142 ,  212 ,  220 , or a series of separate pieces circumferentially mounted within the conduit  102 ,  122 ,  132 ,  142 ,  212 ,  220 . In still other implementations, the first and second stop members  106 ,  226 ,  270 ,  108 ,  128 ,  138 ,  148 ,  168 ,  178 ,  188 ,  264  each include a single protrusion (e.g., bead, dimple, crimp, cutout, etc.). In yet other implementations, the first and second stop members  106 ,  226 ,  270 ,  108 ,  128 ,  138 ,  148 ,  168 ,  178 ,  188 ,  264  each include one or more rods or beams extending across the conduit  102 ,  122 ,  132 ,  142 ,  212 ,  220 . 
     As shown in  FIGS. 1-11 , the mesh puck  110  can be installed and compressed within the conduit  102 ,  122 ,  132 ,  142 ,  212 ,  220  in a variety of ways. 
       FIG. 1  shows a first example retention arrangement  100  for holding a mesh puck  110  within the conduit  102  defined by a pipe  101 . The mesh puck  110  is installed with the first face  112  abutting a first stop member  106  within the conduit  102 . In some implementations, the first stop member  106  is integrally formed with the conduit  102 . In other implementations, the first stop member  106  is separate from the conduit, but pre-installed (e.g., welded, glued, etc.) within the conduit  102  prior to installing the mesh puck  110 . The second stop member  108  is a separate piece from the conduit  102 . The second stop member  108  is slid or otherwise moved within the conduit  102  towards the mesh puck  110 . The second stop member  108  continues to be pressed or otherwise moved towards the mesh puck  110  until a predetermined compression force F is applied to the mesh puck  110  along the mesh axis M. For example, the mesh puck  110  is axially compressed between the first and second stop members  106 ,  108 . Then, the second stop member  108  is affixed (e.g., welded, glued, snap-fit, etc.) to the conduit  102  at a position where the second stop member  108  applies the loading force F to the mesh puck  110 . 
     In some implementations, the mesh puck  110  is mantle-less and held within the conduit  102  of the pipe  101 , which may form part of an exhaust system. As indicated by the break lines in  FIG. 1 , the pipe  101  may extend beyond what is shown. In other implementations, the pipe  101  functions as a mantle for the mesh puck  110 , thereby forming a self-contained unit that can be mounted within the conduit of another pipe or other exhaust system component. In such implementations, the peripheral side of the mesh puck  110  still floats relative to the interiorly facing surface  104  of the pipe  101 . In some such examples, one or both sides of the pipe  101  may extend away from the first and second stop members  106 ,  108  to form a mounting surface for the mantle. In other such examples, the pipe  101  may terminate shortly beyond the first and second stop members  106 ,  108 . 
       FIG. 2  shows a second example retention arrangement  120  for holding a mesh puck  110  within the conduit  102 . The mesh puck  110  is installed with the first face  112  abutting a first stop member  106  within the conduit  102 . In some implementations, the first stop member  106  is integrally formed with the first pipe  101 . In other implementations, the first stop member  106  is separate from the first pipe  101 , but pre-installed (e.g., welded, glued, etc.) within the conduit  102  prior to installing the mesh puck  110 . An end of a second pipe  121  is mechanically coupled to the first pipe  101  so that the second pipe  121  can slide relative to the first pipe  101 . The second pipe  121  defines a second conduit  122  in which a second stop member  128  is disposed. In some implementations, the second stop member  128  is integrally formed with the conduit  122  of the second pipe  121 . In other implementations, the second stop member  128  is separate from the second pipe  121 , but pre-installed (e.g., welded, glued, etc.) within the conduit  122  prior to coupling the second pipe  121  to the first pipe  101 . 
     The second pipe  121  is moved (e.g., slid) relative to the first pipe  101  until the second stop member  128  presses sufficiently against the second face  114  of the mesh puck  110  to apply a predetermined compression force F to the mesh puck  110  along the mesh axis M. In some examples, the second pipe  121  fits within the conduit  102  of the first pipe  101  and slides along the interiorly facing surface  104  of the first pipe  101 . In other examples the second pipe  121  fits over the first pipe  101  and the second stop member  128  slides through one or more slots (or drops into one or more openings) defined in the first pipe  101 . The second pipe  121  is then axially fixed (e.g., welded, glued, etc.) relative to the first pipe  101 . In certain examples, the second pipe  121  is fixed to the first pipe  101  at a location A spaced from the mesh puck  110 , thereby protecting the mesh puck  110  from the securing process (e.g., from heat, contaminants, etc.) compared to when the second stop member  108  is installed within the same pipe  101 . 
       FIG. 3  shows a third example retention arrangement  130  for at least axially retaining a mesh puck  110 . The mesh puck  110  is installed at an end of a conduit  102  defined by a first pipe  101 . The mesh puck  110  is installed with the first face  112  abutting a first stop member  106  within the conduit  102 . In the example shown, the first stop member  106  is integrally formed with the first pipe  101  (e.g., by beading, crimping, or dimpling the first pipe  101 ). In other examples, however, the first stop member  106  may be a separate piece pre-installed within the conduit  102 . The first stop member  106  is located such that the mesh puck  110  is disposed at an end of the pipe  101  with the second face  114  facing an exterior of the pipe  101 . 
     A second pipe  131  is aligned with the first pipe  101  so that an end of the second pipe  131  aligns with the second face  114  of the mesh puck  110 . The end of the second pipe  131  defines a conduit  132  having a smaller inner cross-dimension (e.g., diameter) than the interiorly facing surface  104  of the conduit  102 . A radial shoulder  138  extends outwardly from the conduit  132  at the end of the pipe  131  to define a shoulder facing the conduit  102 . The second pipe  131  is moved relative to the first pipe  101  so that the radial shoulder  138  abuts and applies a compression force F to the second face  114  of the mesh puck  110 . In  FIG. 3 , the second pipe  131  has a consistent cross-dimension that is smaller than a cross-dimension of the mesh puck  110 . The radial shoulder  138  is defined by a radial flange extending outwardly from the conduit  132 . 
       FIG. 4  shows a fourth example retention arrangement  140  or at least axially retaining a mesh puck  110 . A pipe  101  defines a conduit  102  extending axially between first and second ends  141 ,  143 . A first stop member  106  is disposed within the conduit  102  between the first and second ends  141 ,  143 . A second stop member  148  also is disposed within the conduit  102  between the first stop member  106  and the second end  143 . The second stop member  148  is spaced downstream from the first stop member  106  by a retention section  145 . 
     The second stop member  148  includes a ramped portion  149  and a shoulder portion  147 . The shoulder portion  147  faces the first stop member  106 . In some examples, the second stop member  148  is formed by the conduit  102  tapering radially inwardly along a section as the conduit  102  extends from the second end  143  towards the first stop member  106 . In other examples, a plurality of second stop members  148  are formed by circumferentially spaced sections of the conduit  102  tapering radially inwardly. 
     The mesh puck  110  is inserted into the conduit from the second end  143  and moved towards the first stop member  106 . As the mesh puck  110  travels along the conduit  102 , the puck  110  is radially compressed by the ramped portion(s)  149  of the second stop member(s)  148  until the puck  110  reaches the retention section  145 . The puck  110  resiliently expands out into the retention section  145  after clearing the ramped portion(s)  149 . The shoulder(s)  147  of the second stop member(s)  148  axially retains the puck  110  within the retention section  145 . 
     In certain implementations, the retention section  145  is sufficiently short that the mesh puck  110  is axially compressed between the first and second stop members  106 ,  148 . A user may need to apply an axial compression load to the mesh puck  110  to dispose the mesh puck  110  fully within the retention section  145 . For example, a user may push the mesh puck  110  along the conduit  102  until the first face  112  of the mesh puck  110  abuts the first stop member  106 . The user may then continue to push against the second face  114  of the mesh puck  110  until the second face  114  clears the second stop member(s)  148 . 
       FIG. 5  illustrates a fifth example retention arrangement  150  for holding a mesh puck  110  within a conduit  102 . In certain implementations, the mesh puck  110  is installed within the conduit  102  by sliding the puck  110  in from an end of the pipe  101 . In some implementations, the conduit  102  does not initially include any stop members. In other implementations, the conduit  102  initially includes a first stop member  106  (e.g., an integral protrusion, a separately installed piece, a deformation—dimple, crimp, bead—of the pipe, etc.). 
     An axial compression force F is applied to the mesh puck  110  using one or more compressing members (e.g., pressing plates)  152 ,  154 . In some implementations, the axial compression force F is applied by a first compressing member  152  pushing the mesh puck  110  against the first stop member  106  (if initially included). In other implementations, the axial compression force F is applied by first and second compressing members  152 ,  154  pushing on the opposite faces  114 ,  112  of the mesh puck  110  to axially compress the mesh along the mesh axis M. When the mesh puck  110  is suitable compressed (e.g., when a predetermined amount of compression force F is applied to the mesh puck  110 ), at least the second stop member  158  is added to the conduit  102  at the second face  114  of the mesh puck  110  to retain the mesh puck  110  in the compressed state. In certain examples, both first and second stop members  156 ,  158  are added to conduit  102  at opposite sides of the mesh puck  110  to retain the mesh puck  110  in the compressed state. For example, one or both stop members  156 ,  158  are added by beading, dimpling, or crimping the pipe  101 . Once the stop members  156 ,  158  are added, the compressing members  152 ,  154  can be removed. 
       FIG. 6  illustrates a sixth example retention arrangement  160  for holding a mesh puck  110  within the conduit  102 . In certain implementations, the mesh puck  110  is installed within the conduit  102  by sliding the puck  110  in from an end of the pipe  101 . The conduit  102  includes a first stop member  106  (e.g., an integral protrusion, a separately installed piece, a deformation—dimple, crimp, bead—of the pipe, etc.) against which the first face  112  of the mesh puck  110  abuts. A predetermined compression force F is applied to the mesh puck  110  (e.g., using compressing plates  152 ,  154 ). When the mesh puck  110  is in the compressed state, a second stop member  168  is formed (e.g., by beading, dimpling, crimping, etc.) along the periphery  116  of the mesh puck  110 . The second stop member  168  extends into the periphery  116  of the mesh puck  110  instead of along the second face  114  of the mesh puck  110 . The second stop member  168  cooperates with the first stop member  106  is maintain the compression force F on at least a portion of the mesh puck  110 . For example, the compression force F may be maintained on the portions of the mesh puck  110  disposed between the first and second stop members  106 ,  168 . In still other implementations, the first stop member  106  may extend into the periphery  116  of the mesh puck  110 . In such implementations, a middle portion of the mesh puck  110  is maintained in an axially compressed state between the first and second stop members. 
       FIG. 10  illustrates a seventh example retention arrangement  190  for holding a mesh puck  110  within the conduit  102 . In certain implementations, the mesh puck  110  is installed within the conduit  102  by sliding the puck  110  in from an end of the pipe  101 . The retention arrangement  190  includes one or more ribs extending across the mesh puck  110  (e.g., across a diameter of the mesh puck or across a chord of the mesh puck) to axially retain the mesh puck  110  within the conduit  102 . An outer periphery  116  of the mesh puck  110  is not directly connected to the conduit  102 . Rather, the outer peripheral surface  116  of the mesh puck  110  is able to float relative to the conduit  102 . In some examples, the ribs are used as second stop members  198  in combination with any of the previously described first stop members  106 ,  156 . In other examples, the ribs are used as first stop members  196  in combination with any of the previously described second stop members  108 ,  128 ,  138 ,  148 ,  158 ,  168 . In still other examples, the ribs are used as both first stop members  196  and second stop members  198 . In yet still other examples, the ribs are disposed at one or both axial end surfaces  112 ,  114  of the mesh puck  110  in addition to any of the previously described first and second stop members  106 ,  156 ,  108 ,  128 ,  138 ,  148 ,  158 ,  168 . In certain implementations, the ribs  196 ,  198  cooperate with each other or with other first and/or second stop members) to maintain the mesh puck  110  in the axially compressed state. In certain examples, the ribs have sufficiently small widths and are sufficiently spaced to mitigate blocking exhaust flow through the conduit  102 . 
     In general, the first and second stop members  106 ,  226 ,  270 ,  156 ,  108 ,  128 ,  138 ,  148 ,  158 ,  168 ,  178 ,  188 ,  264  extend radially inwardly from the interiorly facing surface  104  of the conduit  102 ,  212  (or from an interiorly facing surface of a second conduit  122 ,  132 ,  142 ,  220 ) by less than the cross-dimension D of the mesh puck  110 . In certain implementations, the cross-dimension D of the mesh puck  110  is between about 1 inch and 14 inches. In certain implementations, the cross-dimension D of the mesh puck  110  is between about 2 inch and 12 inches. In certain implementations, the cross-dimension D of the mesh puck  110  is between about 4 inch and 10 inches. In certain examples, the cross-dimension D of the mesh puck  110  is about 4 inches. In certain examples, the cross-dimension D of the mesh puck  110  is about 5 inches. In certain examples, the cross-dimension D of the mesh puck  110  is about 6 inches. In certain examples, the cross-dimension D of the mesh puck  110  is about 7 inches. In certain examples, the cross-dimension D of the mesh puck  110  is about 8 inches. 
     In some implementations, no portion of the retention arrangement  100 ,  120 ,  130 ,  140 ,  150 ,  160 ,  230 ,  260  extends across the cross-dimension D or chord of the mesh puck  110 . In certain implementations, the first and second stop members  106 ,  226 ,  270 ,  156 ,  108 ,  128 ,  138 ,  148 ,  158 ,  168 ,  178 ,  188 ,  264  extend radially inwardly from the interiorly facing surface  104 ,  134 ,  144  of the conduit  102 ,  132 ,  142 ,  212 ,  220  by less than a tenth of the cross-dimension D of the mesh puck  110 . In certain implementations, the first and second stop members  106 ,  226 ,  270 ,  156 ,  108 ,  128 ,  138 ,  148 ,  158 ,  168 ,  178 ,  188 ,  264  extend radially inwardly from the interiorly facing surface  104 ,  134 ,  144  of the conduit  102 ,  132 ,  142 ,  212 ,  220  by between a tenth and a twentieth of the cross-dimension D of the mesh puck  110 . In an example, the first and second stop members  106 ,  226 ,  270 ,  156 ,  108 ,  128 ,  138 ,  148 ,  158 ,  168 ,  178 ,  188 ,  264  extend radially inwardly from the interiorly facing surface  104 ,  134 ,  144  of the conduit  102 ,  132 ,  142 ,  212 ,  220  by about ⅛ th  inch. In an example, the first and second stop members  106 ,  226 ,  270 ,  156 ,  108 ,  128 ,  138 ,  148 ,  158 ,  168 ,  178 ,  188 ,  264  extend radially inwardly from the interiorly facing surface  104 ,  134 ,  144  of the conduit  102 ,  132 ,  142 ,  212 ,  220  by about ¼ th  inch. In other implementations, the first and/or second stop members  106 ,  226 ,  270 ,  156 ,  108 ,  128 ,  138 ,  148 ,  158 ,  168 ,  178 ,  188 ,  264  may extend across the mesh as ribs (e.g., see  FIG. 10 ). 
     In certain implementations, the first and second stop members  106 ,  226 ,  270 ,  156 ,  108 ,  128 ,  138 ,  148 ,  158 ,  168 ,  178 ,  188 ,  264  cover no more than about 30% of the end faces  112 ,  114  of the mesh puck  110 . In certain implementations, the first and second stop members  106 ,  226 ,  270 ,  156 ,  108 ,  128 ,  138 ,  148 ,  158 ,  168 ,  178 ,  188 ,  264  cover between about 10% to about 30% of the end faces  112 ,  114  of the mesh puck  110 . In certain implementations, the first and second stop members  106 ,  226 ,  270 ,  156 ,  108 ,  128 ,  138 ,  148 ,  158 ,  168 ,  178 ,  188 ,  264  cover no more than about 20% of the end faces  112 ,  114  of the mesh puck  110 . 
     In certain implementations, one or more additional support members may extend across the mesh puck  110  to aid in axially retaining the mesh puck. For example, one or more rods or beams may extend across the cross-dimension or chord of the conduit  102  along the first and/or second end face  112 ,  114  of the mesh puck. The ribs have sufficiently small widths and are sufficiently spaced to mitigate blocking exhaust flow through the conduit  102 . 
     In certain implementations, the mesh puck  110  is inhibited from rotating relative to the conduit  102 . In some examples, the mesh puck  110  is inhibited from rotating by the axial compression maintained on the mesh puck  110 . In other examples, one or more anti-rotation features are disposed within the conduit  102  to maintain a rotational orientation of the mesh puck  110 . In certain examples, the anti-rotation feature extends into the peripheral side of the mesh puck  110  without attaching to the mesh puck  110  at a specific point. For example, in some implementations, the anti-rotation feature is not welded or glued to the mesh puck  110 . Rather, the mesh puck  110  can move small amounts (e.g., vibrate) relative to the anti-rotation feature during operation of the exhaust aftertreatment device. In other implementations, an anti-rotation tab is secured (e.g., welded or glued) onto the mesh puck  110 . The tab is sized to fit into a notch in the conduit  102 . However, the tab is not fixedly held in the notch (i.e., is not welded or glued to the notch). In certain examples, an anti-rotation feature includes a dimple (i.e., a dimpled portion of the conduit). In certain examples, the anti-rotation feature is sufficiently small that the anti-rotation feature alone could not cooperate with the first stop member to maintain the mesh puck  110  in the axially compressed state. 
       FIGS. 8 and 9  show how the mesh puck  110  and retention arrangement  100 ,  120 ,  130 ,  140 ,  150 ,  160 ,  230 ,  260  can be used within an example exhaust treatment device  200 . The exhaust treatment device  200  includes an exhaust passage  202  through which exhaust flows. A mixing and dosing assembly  205  may be disposed along the exhaust passage  202 . In the example shown, the outer housing for the mixing and dosing assembly  205  is hidden for ease in viewing. 
     A treatment substrate (e.g., a diesel-particulate filter)  207  may be disposed upstream of the mixing and dosing assembly  205 . Another treatment substrate (e.g., an SCR substrate) may be disposed downstream of the mixing and dosing assembly  205  (beyond what is shown in  FIG. 8 ). The mesh puck  110  and a corresponding implementation of a retention arrangement  230  may be used in the mixing and dosing assembly  205 . 
     In certain implementations, the mixing and dosing assembly  205  includes a deflection baffle  210  defining a passage  212  through which exhaust passes from upstream of the deflection baffle  210  to downstream of the deflection baffle  210 . The mesh puck  110  is disposed at the passage  212  so that the first mesh face  112  faces upstream of the passage  212  and the second mesh face  114  faces downstream of the passage  212 . In certain examples, exhaust must pass through the mesh puck  110  to flow past the deflection baffle  210 . In certain examples, the deflection baffle passage  212  is positioned and oriented to induce swirling of the exhaust flowing through the passage  212 . In certain examples, a restriction baffle  240  is disposed downstream of the deflection baffle  210 . 
     In certain implementations, a perforated conduit (e.g., cylindrical tube, conical tube, frustroconical tube, etc.)  220  is installed upstream of the passage  212 . In certain examples, the perforated conduit  220  is aligned with the deflection baffle passage  212 . A doser for injecting reactant (e.g., aqueous urea) may be mounted at a doser mounting location  250  at an end of the perforated conduit  220 . Example mixing and dosing assemblies  205  suitable for use with the mesh puck  110  and retention arrangements  100 ,  120 ,  130 ,  140 ,  150 ,  160 ,  230 ,  260  disclosed herein are shown and described in U.S. Pat. No. 10,179,315, the disclosure of which is hereby incorporated herein by reference in its entirety. 
     In the example shown, the mesh puck  110  can be mounted within a retention arrangement  230  coupled between the deflection baffle  210  and the perforated conduit  220 . The retention arrangement  230  includes a first conduit  221  defining a first stop member  226  (e.g., shoulder) against which the first face  112  of the mesh puck  110  abuts. A second conduit  182  defining a second stop member  188  (e.g., shoulder) is pressed into the first conduit until the second shoulder  188  abuts the second face  114  of the mesh puck  110 . The first and second shoulders  226 ,  188  are pressed towards each other until a predetermined compression force is applied to the mesh puck along the mesh axis M. Then, the first and second conduits  221 ,  182  are secured to each other (e.g., by welding, adhesive, etc.). In other examples, any of the retention arrangements  100 ,  120 ,  130 ,  140 ,  150 ,  160 ,  260  can be utilized with the deflection baffle  210  and perforated conduit  220 . 
     In some implementations, the first conduit  221  attaches to the perforated conduit  220 . In other implementations, the first conduit  221  is integral with the perforated conduit  220 . In certain implementations, the second conduit  182  attaches to the deflection baffle  210 . In other implementations, the first and/or second conduits  221 ,  182  may attach to intervening structure between the perforated conduit  220  and the deflection baffle  210 . In the example shown, the second conduit  182  is integral with a frustroconically-shaped conduit  181 , which attaches to the deflection baffle  210 . In other examples, the second conduit  182  may mechanically attach to a frustroconically-shaped conduit. 
     In certain implementations, the mesh puck  110  is sized (e.g., the wire diameter and mesh density are sized) to inhibit unhydrolized/unvaporized reductant from passing through the mesh puck  110 . For example, the unhydrolized/unvaporized reductant may impinge on the mesh puck  110  and break into smaller droplets prior to reaching an impact plate or the surrounding housing or entering the restriction baffle  240  downstream of the mesh puck  110 . Breaking the droplets both decreases the size of and increases the number (and hence total surface area) of the droplets. The smaller size and increased surface area promotes evaporation of the droplets. 
     In certain implementations, the mesh puck  110  absorbs heat from the exhaust passing therethrough. The mesh puck  110  may pass some of the absorbed heat to the impinging droplets of reductant injected by the doser, which enhances evaporation of the droplets and/or inhibits deposition of the droplets on the body  205  and impaction plate. Droplets that impinge on the mesh puck  110  reside within the exhaust flow while disposed on the mesh puck  110 , which enhances evaporation of the droplets. In certain implementations, the mesh puck  110  heats up faster than a solid surface would, especially during transient exhaust conditions. 
       FIGS. 11 and 12  illustrate another retention arrangement  260  for holding the mesh puck  110  within the example exhaust treatment device  200  of  FIG. 8 . In the example shown in  FIG. 11 , the portions of the conduit  202  upstream of the mixing and dosing assembly  205  are hidden for ease in viewing. A treatment substrate (e.g., a diesel-particulate filter)  207  may be disposed upstream of the mixing and dosing assembly  205  (e.g., see  FIG. 8 ). Another treatment substrate (e.g., an SCR substrate) may be disposed downstream of the mixing and dosing assembly  205  (beyond what is shown in  FIG. 10 ). The retention arrangement  260  is shown holding the mesh puck  110  in the passage  212  downstream of the deflection baffle  210 . 
     The mesh puck  110  is disposed at the passage  212  so that the first mesh face  112  faces upstream of the passage  212  and the second mesh face  114  faces downstream of the passage  212 . In certain examples, the deflection baffle passage  212  is positioned and oriented to induce swirling of the exhaust flowing through the passage  212 . In certain examples, a restriction baffle  240  is disposed downstream of the deflection baffle  210 . In certain implementations, the perforated conduit  220  is installed upstream of the passage  212  in alignment with the deflection baffle passage  212 . The doser mounting location  250  is disposed at an end of the perforated conduit  220 . 
     Details of example mixing and dosing assemblies  205  suitable for use with the mesh puck  110  and retention arrangements  260  disclosed herein are shown and described in U.S. Pat. No. 10,179,315, the disclosure of which is hereby incorporated herein by reference in its entirety. 
     In the example shown, the mesh puck  110  can be mounted within a retention arrangement  260  coupled between the deflection baffle  210  and the perforated conduit  220 . The retention arrangement  260  includes a first conduit  262  defining a first stop member  264  (e.g., a shelf) on which the second face  114  of the mesh puck  110  seats. A cowl  266  fits over the mesh puck  110  and first conduit  262 . The cowl  266  defines a second stop member  270  (e.g., a shoulder) that cooperates with the shelf  264  to axially compress the mesh puck  110  therebetween along the mesh axis M. In certain examples, the shoulder  270  and shelf  264  extend over an outer peripheral area of the end faces  112 ,  114  of the mesh puck  110 , leaving a majority of each end face  112 ,  114  exposed to flow passing through the perforated conduit  220 . 
     In certain implementations, a first axial end of the first conduit  262  mechanically attaches (e.g., by welding, adhesive, or friction-fit) to the deflection baffle  210  while an opposite second axial end defines the shelf  264 . In certain examples, the first axial end has a frustroconical shape. In certain examples, the second end has a cylindrical shape. In certain examples, the first axial end of the first conduit  262  has a transverse cross-sectional area that is larger than the transverse cross-sectional area of the second axial end. In certain examples, the transverse cross-sectional area of the second axial end is larger than a transverse cross-sectional area of the perforated conduit  220 . 
     The cowl  266  fits telescopingly over the first conduit  262  to enable adjustment of the amount of compressive force applied to the mesh puck  110 . An inner surface  268  of the cowl  266  extends over the periphery  116  of the mesh puck  110  without attaching thereto. Accordingly, the periphery  116  of the mesh puck  110  floats relative to the inner surface  268  of the cowl  266 . Sliding the cowling  266  so that the shoulder  270  moves closer to the shelf  264  increases the compressive pressure applied to the puck  110 . Sliding the shoulder  270  away from the shelf  264  reduces the compressive pressure on the puck  110 . When the desired amount of compressive force is applied to the mesh puck  110 , the cowling  266  is fixed (e.g., by welding or adhesive) to the first conduit  262  at a securement region  272 . In certain implementations, the securement region  272  is offset from the inner surface  268  facing the peripheral edge  116  of the puck  110 . Accordingly, heat from welding the cowl  266  to the conduit  262  does not burn the wires or melt the braise of the mesh puck  110 . 
     In some implementations, the cowl  266  includes a mounting section  274  for coupling to the perforated conduit  220 . For examples, the perforated conduit can be telescopingly fit within an axial end of the cowl  266  and secured (e.g., by welding or adhesive) thereto. In certain examples, the mounting section  274  is recessed radially inward compared to the inner surface  268  opposing the mesh puck  110 . In certain examples, the shoulder  270  provides a radial transition between the inner surface  268  and the mounting section  274 . In other implementations, the cowl  266  is integrally formed with the perforated conduit  220 . 
     In certain implementations, flow guides  280  may be disposed within the perforated conduit  220  (e.g., at the doser tip). In certain examples, the flow guides  280  may inhibit exhaust from depositing on or around the doser tip. In certain examples, the flow guides  280  may generate turbulence (e.g., swirling) local to the doser mounting location  250  to mitigate such deposits. Examples of suitable flow guides  280  are provided in U.S. Provisional Application No. 62/872,780, filed Jul. 11, 2019, and titled “Dosing Conduit Arrangement for Exhaust Aftertreatment Systems,” the disclosure of which is hereby incorporated herein by reference in its entirety. 
     Having described the preferred aspects and implementations of the present disclosure, modifications and equivalents of the disclosed concepts may readily occur to one skilled in the art. However, it is intended that such modifications and equivalents be included within the scope of the claims which are appended hereto.