Patent Publication Number: US-2010123312-A1

Title: Retrofit arrangement for pulse jet dust collectors

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to a system for cleaning filters in a baghouse, and more particularly, to a retrofit arrangement for pulse jet dust collectors for cleaning filters in a baghouse. 
     BACKGROUND OF THE INVENTION 
     The invention relates generally to a system for cleaning filters in a baghouse. In particular, the invention relates to a retrofit arrangement coupling a pulse jet device providing a pressurized fluid to a blowpipe of the baghouse via an existing tubular fixture for cleaning filters in a baghouse with reverse pulses of the pressurized fluid. 
     Filters for removing particulates from a particulate-laden gas stream flowing through a baghouse are known. The particulates are typically generated by an industrial process and carried to the filters in the gas flow stream. The filters include media that is formed into filter cartridges or filter bags, etc. The particulate-laden gas flows through the filters from outside towards inside. The particulates are separated from the gas stream at the outer side of the filters. The filtered gas stream flows through the media and exits the filter through an open end. The filtered gas stream then is conducted to subsequent plant uses or the atmosphere. 
     Over time, a buildup of accumulated particulates form on the outer sides of the filters and becomes thicker and thicker. This increasing buildup of particulates causes an increase in pressure drop across the filters. This increased pressure drop is costly because more power is consumed to generate an effective-flow of gas through the filters. 
     The filters are periodically cleaned to remove the particulate buildup and reduce the pressure drop across the filters. To clean the filters, a pressurized fluid, such as air, is blown into the open end of the filters to dislodge the particulate buildup adhering to their outer sides. Known cleaning systems typically provide a pulse of compressed air into the filters at a supplied pressure in the range of about 70 to 100 PSI. 
     BRIEF SUMMARY OF THE INVENTION 
     The following presents a simplified summary of the invention in order to provide a basic understanding of some example aspects of the invention. This summary is not an extensive overview of the invention. Moreover, this summary is not intended to identify critical elements of the invention nor delineate the scope of the invention. The sole purpose of the summary is to present some concepts of the invention in simplified form as a prelude to the more detailed description that is presented later. 
     In accordance with one aspect of the present invention, a method of replacing an existing threaded coupler on an existing tubular fixture having a first outer diameter and a first inner diameter and secured to a baghouse is provided to couple a pulse jet device providing a pressurized fluid to a blowpipe of the baghouse via the existing tubular fixture. The method includes the steps of disconnecting the blowpipe from the existing tubular fixture by removing the threaded coupler therefrom. The method further includes the steps of providing a spacer sleeve having a second inner diameter, and a second outer diameter in the range of about 95% to about 100% of the first inner diameter, and arranging the spacer sleeve within the existing tubular fixture such that a central axis of the spacer sleeve is generally co-axial with a central axis of the existing tubular fixture. The method further includes the steps of providing a transfer tube having a third inner diameter, and a third outer diameter in the range of about 95% to about 100% of the second inner diameter, and arranging the transfer tube within the spacer sleeve such that a central axis of the transfer tube is generally co-axial with the central axis of the spacer sleeve. The method further includes the steps of coupling the transfer tube to the spacer sleeve, coupling the spacer sleeve to the existing tubular fixture, arranging the blowpipe within the spacer sleeve, providing a supply tube coupled to the pulse jet device, and coupling the supply tube to the transfer tube. 
     In accordance with another aspect of the present invention, a method of replacing an existing threaded coupler on an existing tubular fixture having a first outer diameter, a first inner diameter, and a first length, and secured to a baghouse is provided to couple a supply tube providing a pressurized fluid to a blowpipe of the baghouse via the existing tubular fixture. The method includes the steps of disconnecting the blowpipe from the existing tubular fixture by removing the threaded coupler therefrom. The method further includes the steps of providing a spacer sleeve having a second inner diameter, a second outer diameter in the range of about 95% to about 100% of the first inner diameter, and a second length at least about 75% of the first length, and arranging the spacer sleeve within the existing tubular fixture such that a central axis of the spacer sleeve is generally co-axial with a central axis of the existing tubular fixture and at least a portion of the spacer sleeve is located within the baghouse. The method further includes the steps of providing a transfer tube having a third inner diameter, and a third outer diameter in the range of about 95% to about 100% of the second inner diameter, and arranging the transfer tube within the spacer sleeve such that a central axis of the transfer tube is generally co-axial with the central axis of the spacer sleeve and at least a portion of the transfer tube extends a distance away from the existing tubular fixture. The method further includes the steps of coupling the transfer tube to the spacer sleeve, coupling the spacer sleeve to the existing tubular fixture, arranging the blowpipe within the spacer sleeve, and coupling the supply tube to the transfer tube. The supply tube is a flexible tube adapted to be coupled to a pulse jet device for providing a pressurized fluid to the blowpipe. 
     In accordance with another aspect of the present invention, a retrofit coupling arrangement is provided for replacing an existing threaded coupler on an existing tubular fixture having a first outer diameter, a first inner diameter, and a first length, and secured to a baghouse to couple a pulse jet device providing a pressurized fluid to a blowpipe of the baghouse via the existing tubular fixture. The retrofit coupling arrangement includes a flexible supply tube adapted to be coupled to the pulse jet device, and a spacer sleeve having a second inner diameter, a second outer diameter in the range of about 95% to about 100% of the first inner diameter, and a second length at least about 75% of the first length. The spacer sleeve is arranged within the existing tubular fixture such that a central axis of the spacer sleeve is generally co-axial with a central axis of the existing tubular fixture and at least a portion of the spacer sleeve is located within the baghouse. The retrofit coupling arrangement further includes a transfer tube having a third inner diameter that is substantially equal to an inner diameter of the blowpipe, and a third outer diameter in the range of about 95% to about 100% of the second inner diameter. The transfer tube is arranged within the spacer sleeve such that a central axis of the transfer tube is generally co-axial with the central axis of the spacer sleeve, and at least a portion of the transfer tube extends a distance away from the existing tubular fixture and is adapted to be coupled to the flexible supply tube. The transfer tube is spaced a distance of less than about 25 millimeters from the blowpipe to maintain a substantially consistent cross-sectional flow area for the pressurized fluid within the existing tubular fixture, and the transfer tube is coupled to the spacer sleeve. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The foregoing and other aspects of the present invention will become apparent to those skilled in the art to which the present invention relates upon reading the following description with reference to the accompanying drawings, in which: 
         FIG. 1  is a schematic representation of an example baghouse and cleaning system; 
         FIG. 2  is an enlarged, sectional view of Detail area  2 ,  3 ,  4  of  FIG. 1  illustrating a prior art coupling arrangement between a supply tube and a blowpipe; 
         FIG. 3  is an enlarged, sectional view of Detail area  2 ,  3 ,  4  of  FIG. 1  illustrating a first example coupling arrangement between a supply tube and a blowpipe in accordance with one aspect of the present invention; and 
         FIG. 4  is similar to  FIG. 3 , but illustrates a second example coupling arrangement between a supply tube and a blowpipe n accordance with another aspect of the present invention. 
     
    
    
     DESCRIPTION OF EXAMPLE EMBODIMENTS 
     Example embodiments that incorporate one or more aspects of the present invention are described an illustrated in the drawings. These illustrated examples are not intended to be a limitation on the present invention. For example, one or more aspects of the present invention can be utilized in other embodiments and even other types of devices. 
     Turning to the shown example of  FIG. 1 , a baghouse  20  incorporating a reverse pulse filter cleaning system  22  is schematically illustrated. It is to be understood that the following provides a description of one example baghouse, and that the retrofit arrangement of the subject application can be utilized in various baghouses having various filter configurations. The baghouse  20  is defined by an enclosed housing  24 . The housing  24  is made from a suitable material, such as sheet metal. Particulate-laden gas D flows into the baghouse  20  from an inlet  26  at a temperature generally between about ambient temperature and about 450° F., or even higher. The particulate-laden gas D is filtered by a plurality of filters  40  located within the baghouse  20 . Filtered or clean gas C exits through an outlet  42  of the baghouse  20 . 
     The baghouse  20  can be divided into a “dirty gas” plenum  44  and a “clean gas plenum  46  by a tubesheet  48  made from a suitable material, such as sheet metal. The inlet  26  is in fluid communication with the dirty gas plenum  44 . The outlet  42  is in fluid communication with the clean gas plenum  46 . The baghouse  20  can also have an accumulation chamber defined by sloped walls  60  located at a lower end of the dirty gas plenum  44 . The accumulation chamber receives and temporarily stores particulates and other debris that are separated from the particulate-laden gas D or fall off of the filters  40 . The stored particulates and debris exit the accumulation chamber through an opening  62 . In one example, the tubesheet  48  can include a plurality of openings (not shown) extending therethrough, while a filter  40  is installed in a respective one of the openings. Each of the filters  40  is mounted within the respective opening so it seals against the tubesheet  48  and isolates the dirty gas plenum  44  from the clean gas plenum  46 . While the filters  40  are illustrated as being mounted to extend in a substantially vertical direction, the filters could be mounted to extend in any direction, for example horizontally or at an angle. By way of example and not limitation, a circumferential resilient mounting band (not shown) can be located in each one of the openings in the tubesheet  48 . The band provides the seal between the filter  40  and the opening in the tubesheet  48 , and any suitable mounting structure may be used to attach, support and seal the filters  40  to the tubesheet  48 . 
     The filters  40  filter particulates from the particulate-laden gas D as the gas passes through each filter. Each filter  40  can include conventional bags and cages, and/or may include pleated filter media. For example, the filter media can be formed into a tubular configuration with a circular cross section. It will be apparent that the filters  40  may be any desired length in order to meet the filtering requirements of the baghouse  20 . The filter media may be constructed of any suitable material for desired filtering requirements and operating conditions. For example, materials such as polyester, acrylic and polypropylene are generally acceptable for operating temperatures in the range of 180° F. to 225° F. Aramid and PPS are suitable for up to 375° F. Fiberglass is suitable for use up to 450° F. 
     The filters  40  are illustrated as having retention devices  120  ( FIG. 1 ) extending circumferentially about the pleated filter media. It is to be understood that conventional filters using bags and cages generally do not include such retention devices  120 . However, where pleated filter cartridges are used, the retention devices  120  serve to hold the pleated filter media in place during reverse pulse cleaning of the filter cartridges  40 . Specifically, the retention devices  120  limit movement of the pleated filter media in a radial outward direction during reverse pulse cleaning. The retention devices  120  may be in the form of a strap or an extruded elastomer. 
     The reverse pulse cleaning system  22  can include a plurality of pulse valves  122  ( FIG. 1 ). Each pulse valve  122  is fluidly connected (directly or indirectly) to a pressurized fluid supply  125 , such as a compressed air manifold or header  124  that supplies compressed fluid, such as air. Still, it is to be understood that various pressurized fluids can be used, including various liquids, gasses, and/or combinations thereof. Each of the pulse valves  122  is arranged to direct compressed air stored in the header  124  through a respective one of a plurality of blowpipes  126  (only one is illustrated). The blowpipes  126  are supported by the housing  24 . Each of the blowpipes  126  has a plurality of nozzles  140 . Periodically, the pulse valves  122  are operated to allow a pulse of compressed air to flow from the header  124 , to the blowpipes  126 , through the nozzles  140  and into the filters  40  while filtering operation of the baghouse  20  continues. The nozzle  140  defines a passage for the cleaning fluid (e.g., air, etc.) delivered from the blowpipe  126 . The baghouse  20  does not have to be shut down during this cleaning operation so it does not go off-line. Still, some baghouses can be compartmentalized to isolate individual compartments that are cleaned off-line. The nozzles  140  can be positioned a predetermined distance from the tubesheet and located along the longitudinal central axis of a respective filter  40 . It will also be apparent that nozzles could be eliminated entirely and openings could be formed in the blowpipe  126  for directing the cleaning pulses P into the filters  40 . 
     The header  124  has an inner diameter D 1  in the range of about 4 inches to 18 inches. Each of the blowpipes  126  has an inner diameter D 2  in the range of about ¾ inch to 4 inches. The valves  122  are appropriately sized to the diameters of the header  124  and blowpipes  126 . 
     After a period of filtering operation of the baghouse  20 , a pressure drop across each of the filters  40  will increase due to the accumulation of particulates separated from the particulate-laden gas flow D and accumulate at the outer surfaces of the filters. The filters  40  are periodically cleaned by directing pulses P of a cleaning fluid, such as compressed air, into the open end of each of the filters (i.e., in a “reverse” or opposite direction to normal filtering gas flow). This cleaning is referred to as reverse pulse cleaning. 
     The reverse pulse cleaning system  22  can also includes a control system (e.g., such as a personal computer or PLC, not shown) for controlling the pulses P of the cleaning fluid. The control system can be open loop or closed loop, and can include various elements, such as a controller, the compressed air supply  125  and a regulator. The controller can have various sensors associated with it for determining the pressure differential or drop across the filters  40 , such as a sensor located in the dirty gas plenum  44  and another sensor located in the clean gas plenum  46 . The pressure differential or drop across the filters  40  is the pressure sensed by sensor in the dirty gas plenum  44  minus the pressure sensed by sensor in the clean gas plenum  46 . 
     Referring to  FIG. 1 , the example reverse pulse cleaning system  22  including the aforedescribed elements is illustrated. The reverse cleaning pulse is provided by the cleaning system  22 . Directing a cleaning pulse of compressed air is done periodically into each filter  40  through its open end. In general, the reverse pulse cleaning system  22  delivers a sufficient flow of fluid as the cleaning pulses P of compressed air to clean the filters  40 . By “pulse”, it is meant a flow of a sufficient volume of gas at a pressure sufficient to overcome the filtering operation flow of particulate-laden gas D in the dirty gas plenum  44  for a limited time duration. The limited time duration may be in the range of about 0.1 second to 0.35 second. The pressure of the cleaning gas delivered by the air supply  125  and regulated by the regulator to the header  124  to generate the cleaning pulse is in the range of about 60 PSI to 100 PSI, and preferably in the range of about 60 PSI to 80 PSI. Still, various other pressures are also contemplated. 
     The volume flow from each of the nozzles  140  at this pressure is sufficient to overcome the operational filtering flow through the respective filters  40  and to dislodge or remove any accumulated particulates and debris from the outer surface of the filters. It is important to realize that the reverse cleaning pulse is delivered while the baghouse  20  is allowing filtering operation. The cleaning pulse locally overcomes the filter gas flow through the filters  40 . Cleaning is done in rows of filters  40 . 
     The cleaning pulse emerging from the nozzle  140  can create a pressure wave along the longitudinal extent of the filters  40 . Due to the suddenly occurring pressure change and the reversal of the flow direction, the filters and accumulated particulate buildup are forced radially outward. The accumulated particulate buildup is separated from the outer surfaces of the filters. The separated accumulated particulate buildup drops into the accumulation chamber defined by the walls  60  and exits the baghouse  20  through the opening  62 . The particulates can then be carried away from the baghouse  20 , for instance, by means of a screw conveyor (not shown). 
     Attention is now directed to  FIGS. 2-4 , which each illustrate an enlarged view of Detail area  2 ,  3 ,  4  of  FIG. 1 . Each of  FIGS. 2-4  showing a different arrangement that couples the pulse jet header  124  to the blowpipe  126 . It is to be appreciated that  FIG. 2  shows a prior art arrangement.  FIGS. 3 and 4  show examples of embodiments in accordance with aspects of the present invention. For clarity, each of  FIGS. 2-4  illustrates a sectional view taken through a portion of Detail area  2 ,  3 ,  4 , such as a central portion thereof. 
     It is to be understood that where a baghouse  20  includes a plurality of blowpipes  126 , each blowpipe  126  can be coupled to a separate header  124 , or alternatively, multiple blow pipes  126  can be coupled together with the a single header  124 . 
     Turning now to  FIG. 2 , a prior art arrangement  200  of coupling the pulse jet header  124  to the blowpipe  126  through a sidewall  202  of the baghouse  20  is illustrated. Generally, a rigid supply tube  204  is coupled to the pulse jet header  124  and extends towards the sidewall  202  in one direction, while an end  206  of the blowpipe  126  extends in a generally opposite direction towards the sidewall  202 . It is to be understood that either of the supply tube  204  or the blowpipe end  206  can extend through the sidewall  202 . A tubular fixture  208  extends through an opening in the sidewall  202 . The tubular fixture  208  includes a first end  210  located within the baghouse  20 , and a second end  212  located outside of the baghouse  20 . The tubular fixture  208  is secured to the sidewall  202  in various manners, such as by fasteners, adhesives, welding, etc. The tubular fixture  208  can be a Schedule 40 pipe, such as a 2.5-inch, 3-inch, or 4-inch Schedule 40 pipe (i.e., about a 2.469-inch, 3.068-inch, or 4.026 internal diameter, respectively), though the tubular fixture  208  may also have various other, such as non-standard, dimensions. The tubular fixture  208  has a cross-sectional area generally larger than both of the supply tube  204  and the blowpipe end  206  such that each of the supply tube  204  and the blowpipe end  206  extend a distance into the tubular fixture  208 . 
     Each of the supply tube  204  and the blowpipe end  206  are coupled to the tubular fixture  208  by a threaded coupler  214 A,  214 B. Each of the threaded couplers  214 A,  214 B can be similar or different, though for brevity only one coupler will be described with the understanding that such description similarly applies to both couplers  214 A,  214 B. The threaded coupler  214 A is a compression arrangement including a compression nut  216 A having internal threads that matingly engage corresponding external threads of the first end  210  of the tubular fixture  208 . The compression nut  216 A compresses a gasket  218 A and a compression retainer ring  220 A between the blowpipe end  206  and the first end  210  of the tubular fixture  208 . Thus, the blowpipe end  206  is sealingly secured, in a removable fashion, to the first end  210  of the tubular fixture  208 . A similar coupler  214 B is provided to sealingly, and removably, secure the supply tube  204  top the second end  212  of the tubular fixture  208 . 
     However, as previously described herein, the pulse jet cleaning system can provide periodic pulses of pressurized fluid in the range of about 60 PSI to 80 PSI, or even 100 PSI or more, to the baghouse  20  in an environment with a relatively high temperature that can reach about 450° F. or higher. Thus, each of the supply tube  204 , the blowpipe end  206 , the tubular fixture  208 , and the threaded couplers  214 A,  214 B are continuously exposed to high pressure, high temperature impulse cycles, and may even be subject to high vibration levels. As a result, either or both of the threaded couplers  214 A,  214 B can work loose and/or even fall off of the ends  210 ,  212  of the tubular fixture  208 . For example, if the threaded coupler  214 A falls off of the first end  210 , the blowpipe end  206  will become disconnected from the tubular fixture  208 , and any pulsed air sent from the header  124  will not flow into the blowpipe  126 , rendering the blowpipe  126  ineffective for cleaning the filters  40 . Moreover, because the threaded coupler  214 A is maintained within the interior of the baghouse  20 , it is generally not visible to service personnel. As a result, a disconnected threaded coupler  214 A and blowpipe end  206  may not be discovered for a relatively long time, and/or without increased difficulty, leading to decreased baghouse efficiency and/or damaged filters  40 . 
     In addition or alternatively, because the tubular fixture  208  has a cross-sectional area generally larger than both of the supply tube  204  and the blowpipe end  206 , the pressurized fluid must travel through the relatively smaller diameter of the supply tube  204 , expand into the relatively larger diameter  222  area of the tubular fixture  208 , and be compressed back into the relatively smaller diameter of the blowpipe end  206 . As a result, increased energy must be expended due to the changes in pressure, volume, and/or velocity of the pressurized air within the relatively larger diameter  222  area of the tubular fixture  208 , leading to decreased system efficiency. 
     Turning now to  FIG. 3 , one example retrofit arrangement  300  of coupling the pulse jet header  124  to the blowpipe  126  through a sidewall  302  of the baghouse  20  is illustrated in accordance with one aspect of the present application. The retrofit arrangement  300  can be a slip-fit arrangement. As before, a tubular fixture  308  extends through an opening in the sidewall  302 . Indeed, the tubular fixture  308  can be the same, existing tubular fixture  208  as shown in  FIG. 2 , remaining from a previous installation, or alternatively, can be newly installed. The tubular fixture  308  includes a first end  310  located within the baghouse  20 , and a second end  312  located outside of the baghouse  20 . The tubular fixture  308  can be secured to the sidewall  302  in various manners, such as by fasteners, adhesives, welding, etc. The tubular fixture  308  includes a first inner diameter, a first outer diameter, and a first length (i.e., the length extending from the first end  310  to the second end  312 ). The tubular fixture  308  can have a generally cylindrical geometry, though it can also have various other geometries. In one example, the tubular fixture  308  can be a Schedule 40 pipe, such as a 2.5-inch, 3-inch, or 4-inch Schedule 40 pipe (i.e., about a 2.469-inch, 3.068-inch, or 4.026-inch internal diameter, and about a 2.375-inch, 3.5-inch, and 4.5-inch outer diameter, respectively), though it is to be understood that the tubular fixture  308  may have various other, such as non-standard, dimensions. 
     Also as before, a supply tube  304  is coupled to the pulse jet header  124  and extends towards the sidewall  302  in one direction, while an end  206  of the blowpipe  126  extends in a generally opposite direction towards the sidewall  302 . It is to be understood that either or both of the supply tube  304  or the blowpipe end  306  can extend through the sidewall  302 . Moreover, the tubular fixture  308  can generally have a cross-sectional area generally larger than both of the supply tube  304  and the blowpipe end  306  to permit each of the supply tube  304  and the blowpipe end  306  extend (i.e., telescope) a distance into the tubular fixture  308 . Furthermore, it is to be understood that the supply tube  304  and the blowpipe end  306  can each have geometries corresponding to that of the tubular fixture  308  so as to be at least partially received therein. 
     Additionally, because the pulse jet headers  124  can be arranged relatively close to the sidewall  302  of the bag house  20 , and because the baghouse  20  is often subject to relatively high temperatures that can deform the sidewalls  302  through which the existing tubular fixture  308  is connected, it can be difficult to maintain axial alignment between the pulse jet headers  124 , the supply tube  304 , and the existing tubular fixture  308 . Thus, it can be beneficial to provide the supply tube  304  as a flexible tube that can compensate for axial misalignment of the pulse jet header  124  relative to the existing tubular fixture  308 . For example, a flexible supply tube  104  is illustrated in  FIG. 1 . The flexible supply tube  304  can compensate for axial misalignment during the retrofit installation, and/or generally continuously during the operation of the baghouse  20 . Similar to rigid supply tubes (i.e., see  FIG. 2 ), the flexible supply tube  304  is adapted to be coupled to the pulse jet headers  124  for providing the pressurized fluid to the blowpipe  126 . Various flexible supply tubes  304  can be utilized. In one example, the flexible supply tube  304  can include a flexible hose or the like formed of a generally flexible material, and/or may include flexible corrugations, etc. The flexible supply tube  304  can be flexible along its entire length, and/or can even have one or more generally rigid portions. Still, it is to be understood that a flexible supply tube is not required. For example, a rigid supply tube can be coupled to and utilized with the transfer tube  320 , or alternatively, the transfer tube  320  can be coupled directly to the pulse jet header  124 . 
     Thus, as shown in  FIG. 3 , the flexible supply tube  304  can be indirectly coupled to the tubular fixture  308  by way of a transfer tube  330 . For example, at least a portion of the transfer tube  330  can extend a distance away from the existing tubular fixture  308  and be adapted to be coupled to the flexible supply tube  304 . The transfer tube  330  can be at least partially received within the supply tube  304 , and can be coupled thereto by fasteners, adhesives, welding, etc. In one example, the supply tube  304  can be coupled to the transfer tube  330  by a compression clamp  332  or the like extending about an outer perimeter thereof. 
     However, because the existing tubular fixture  308  can have a cross-sectional area generally larger than the supply tube  304 , transfer tube  330  and/or the blowpipe end  306 , the retrofit arrangement  300  can further be provided with a spacer sleeve  340 . The spacer sleeve  340  can be arranged within the existing tubular fixture  308  such that a central axis  342  of the spacer sleeve  340  is generally co-axial with a central axis of the existing tubular fixture. The spacer sleeve  340  includes a second inner diameter, a second outer diameter, and a second length (i.e., the length extending from one end to the other). To provide a good fit within the existing tubular fixture  308 , the second outer diameter can be in the range of about 90% to about 100% of the first inner diameter of the existing tubular fixture  308 , or even about 95% to about 100% of the first inner diameter of the existing tubular fixture  308 . As a result, a good fit can be established between the spacer sleeve  340  and the existing tubular fixture  308 . Still, an additional spacer (not shown) can be provided therebetween. Moreover, it can be beneficial to provide the second length of the spacer sleeve  340  to be at least about 75% of the first length of the existing tubular fixture  308  such that the spacer sleeve  340  is supported along its length to inhibit, such as prevent, misalignment, binding, etc., and/or inadvertent disengagement thereof. Thus, as shown, at least a portion of the spacer sleeve  340  can be arranged within the existing tubular fixture  308  so as to be located within the baghouse  20  (i.e., interior of the baghouse sidewall  302 ). 
     The transfer tube  330  can have a third inner diameter, a third outer diameter, and a third length (i.e., the length extending from one end to the other). As discussed previously herein, where the tubular fixture  308  has a cross-sectional area generally larger than both of the supply tube  304  or transfer tube  330  and the blowpipe end  306 , it can be undesirable for the pressurized fluid to expand into the relatively larger diameter area of the tubular fixture  308 , and be compressed back into the relatively smaller diameter of the blowpipe end  306 . Thus, it can be beneficial to have the internal cross-sectional area of the transfer tube  330  (i.e., the third inner diameter) to be generally similar, such as identical, to the internal cross-sectional area of the blowpipe end  306 . In one example, where the blowpipe end  306  is generally a 1.5-inch pipe, such as a 1.5-inch Schedule 40 pipe (i.e., about a 1.610-inch internal diameter, and about a 1.9-inch outer diameter), it can be beneficial for the transfer tube  330  to similarly be a 1.5-inch Schedule 40 pipe (i.e., having the third inner diameter be about 1.610-inches). Moreover, it can also be beneficial to axially arrange the ends of the blowpipe end  306  and the transfer tube  330  to be spaced a relatively small distance S apart, such as a distance of less than about one inch (i.e., about 25 millimeters), or even less than about 0.4 inches (i.e., about 10 millimeters), so as to maintain a substantially consistent cross-sectional flow area for the pressurized fluid within the existing tubular fixture  308 . In addition or alternatively, a spacer (not shown) can also be provided between the blowpipe end  306  and the transfer tube  330  to reduce the distance S. Generally, the blowpipe  126  and blowpipe end  306 , are fixed within the baghouse  20 , such as by a hitch pin or the like. Thus, the distance S may be adjusted via the transfer tube  330 , although it may be possible to adjust the position of the blowpipe  126 . 
     Similarly, to provide a good fit within the spacer sleeve  340 , the transfer tube  330  can have a third outer diameter in the range of about 90% to about 100% of the second inner diameter of the spacer sleeve  340 , or even about 95% to about 100% of the second inner diameter of the spacer sleeve  340 . In one example, wherein the transfer tube  330  is a 1.5-inch Schedule 40 pipe (i.e., about a 1.610-inch internal diameter, and about a 1.9-inch outer diameter) so as to be similar to the blowpipe end, it can be beneficial for the spacer sleeve  340  to be a 2-inch Schedule 80 pipe (i.e., about a 1.939-inch internal diameter, and about a 2.375 inch outer diameter). Thus, in this configuration, the third outer diameter of the transfer tube  330  (i.e., about 1.9-inches) is approximately 98% of the second inner diameter (i.e., 1.939-inches) of the spacer sleeve  340 . As a result, a good fit can be established between the transfer tube  330  and the spacer sleeve  340 . During assembly, the transfer tube  330  can be arranged within the spacer sleeve  340  such that a central axis (not shown) of the transfer tube  330  is generally co-axial with a central axis  342  of the spacer sleeve  340 . 
     The transfer tube  330  and spacer sleeve  340  can each be coupled to the tubular fixture  308 , directly or indirectly, in various manners. In one example, the transfer tube  330  can be coupled to the tubular fixture  308  by a threaded coupler  314  which can be similar to, or even the same as, the existing threaded coupler  214 B as shown in  FIG. 2 , remaining from a previous installation, or alternatively, can be newly installed. Thus, in one example, the threaded coupler  314  can be a compression arrangement including a compression nut  316  having internal threads that matingly engage corresponding external threads of the first end  310  of the tubular fixture  308 . The compression nut  316  can compress a seal gasket  318  and a compression retainer ring  320  between the transfer tube  330  and the first end  310  of the tubular fixture  308 . Thus, the transfer tube  330  can be sealingly secured, in a removable fashion, to the first end  310  of the tubular fixture  308 . 
     In another example, the transfer tube  330  can be removably or non-removably coupled to the spacer sleeve  340  fasteners, adhesives, welding, etc. As shown, the transfer tube  330  can be welded to the spacer sleeve  340  by one or more weld(s)  350 . The weld(s)  350  can be generally continuous about an outer perimeter of the transfer tube  330 , so as to provide a substantially sealed joint, or may include a plurality of welds extending about portions of the transfer tube  330 . In addition or alternatively, an additional seal element or the like (not shown) can be provided between the transfer tube  330  and the spacer sleeve  340 . In the case of a retrofit, the transfer tube  330  can be welded to the spacer sleeve  340  in a factory, or may even be welded on-site. In either case, the transfer tube  330  can be welded to the spacer sleeve  340  before, or even after, the spacer sleeve  340  is arranged within the existing tubular fixture  308 . Thus, the transfer tube  330  can be sealingly secured, in a generally non-removable fashion, to the spacer sleeve  340 . As a result, in the instant retrofit arrangement  300 , the transfer tube  330  is directly coupled and sealed to the existing tubular fixture  308 , while the spacer sleeve  340  is indirectly coupled and sealed to the existing tubular fixture  308 . 
     Turning now to the example shown in  FIG. 4 , another example retrofit arrangement  400  of coupling the pulse jet header  124  to the blowpipe  126  through a sidewall  402  of the baghouse  20  using a slip-fit arrangement is illustrated in accordance with another aspect of the present application. It is to be understood that reference numbers of the  400 -series (i.e.,  400 ,  402 ,  404 , etc.) are used to correspond to reference numbers of the  300 -series of  FIG. 3 , and are intended to indicate similar, such as identical, elements (i.e.,  400  is similar to  300 ,  402  is similar to  302 , etc.), incorporating all description thereof. Substantially different or new elements are illustrated with different reference numbers. 
     As shown, the transfer tube  430  is arranged generally within the spacer sleeve  440 , and is sealingly secured thereto by one or more welds  450 . However, the threaded coupler (i.e.,  314 , see  FIG. 3 ) is not used. Instead, the spacer sleeve  440  can be welded to the existing tubular fixture  408  by one or more weld(s)  470 . The weld(s)  470  can be generally continuous about an outer perimeter of the spacer sleeve  440 , so as to provide a substantially sealed joint, or may include a plurality of welds extending about portions of the spacer sleeve  440 . In addition or alternatively, an additional seal element or the like (not shown) can be provided between the existing tubular fixture  408  and the spacer sleeve  440 . In the case of a retrofit, the spacer sleeve  440  can be welded on-site to the existing tubular fixture  408 . As a result, in the instant retrofit arrangement  400 , the transfer tube  430  is indirectly coupled and sealed to the existing tubular fixture  408 , while the spacer sleeve  440  is directly coupled and sealed to the existing tubular fixture  408 . 
     In addition or alternatively, as shown in  FIG. 4 , the blowpipe  480  can be indirectly coupled to the spacer sleeve  440  by a blowpipe adapter  482 . In one example, as discussed herein, the blowpipe  126  may be a 2.5-inch Schedule 40 pipe that would not fit within the spacer sleeve  440 . In other examples, the blowpipe  480  may have non-standard dimensions, and/or may be physically arranged at a distance from the existing tubular fixture  408 . Still, it is to be understood that the foregoing discussion of the blowpipe end  306  relative to the spacer sleeve  340  (i.e., see  FIG. 3 ) applies similarly to the blowpipe adapter  482  and spacer sleeve  440 . Similarly, the blowpipe adapter  482  can be utilized with the arrangement  300  of  FIG. 3 . The blowpipe adapter  482  can have a first end that is removably or non-removably coupled to an end of the blowpipe  480  by a suitable coupler element  484 , and/or fasteners, welding, adhesives, etc. A flexible intermediate element (not shown) may even be provided between the blowpipe  480  and the blowpipe adapter  482 . The blowpipe adapter  482  can also have a second end arranged within the spacer sleeve  440  so as to be generally co-axial therewith. The second end of the blowpipe adapter  482  can also be arranged less than about one inch (i.e., 25 millimeters) from the end of the transfer tube  430 . Similar to the transfer tube  430 , the second end of the blowpipe adapter  482  can have a fourth outer diameter in the range of about 90% to about 100% of the second inner diameter of the spacer sleeve  440 , or even about 95% to about 100% of the second inner diameter of the spacer sleeve  440  so as to provide a good fit therewith. For example, the blowpipe adapter can be a 1.5-inch Schedule 40 pipe. 
     An example method of replacing the existing threaded coupler on the existing tubular fixture will now be described, incorporating associated elements discussed herein. In short, at least one threaded coupler can be replaced with a slip-fit arrangement, such as the retrofit arrangements  300 ,  400  discussed herein. It is to be understood that the following steps can be performed in various orders, and that more or less steps may be included. 
     Turning briefly to  FIG. 2 , the blowpipe end  206  is disconnected from the existing tubular fixture  208  by removing the threaded coupler  214 A, and associated elements (i.e.,  216 A,  218 A,  220 A) therefrom. Similarly, the rigid supply tube  204  can be disconnected from the tubular fixture  208  by removing the threaded coupler  214 B, and associated elements (i.e.,  216 B,  218 B,  220 B) therefrom. Turning now to  FIG. 3 , the transfer tube  330  can be arranged within the spacer sleeve  340  so as to be generally co-axial therewith, and may be directly or indirectly coupled thereto. In one example, the transfer tube  330  can be welded (i.e., weld  350 ) to the spacer sleeve  340 . The spacer sleeve  340  can be arranged within the existing tubular fixture  308  so as to be generally co-axial therewith, and may be directly or indirectly coupled thereto. In one example, the spacer sleeve  340  can be welded (i.e., weld  470 ) to the existing tubular fixture  308 . In another example, the transfer tube  330  can be coupled to the existing tubular fixture  308  by a threaded coupler  314  such that the spacer sleeve  340  is indirectly coupled to the tubular fixture  308 . Thus, each of the tubular fixture  308 , transfer tube  330 , spacer sleeve  340  can be arranged generally co-axially. The blowpipe end  306  can be arranged within one end of the spacer sleeve  340  generally opposite the transfer tube  330 , and spaced a relatively small distance therefrom, such as less than about one inch (i.e., about 25 millimeters). Finally, the flexible supply tube  304  is coupled at one end to the pulse jet header  124 , and at the other end to the transfer tube  330 , such as by a compression clamp  332  or the like. Thus, the pulse jet header  124  is arranged in fluid communication with the blowpipe  126  via the existing tubular coupler  308 . Moreover, the slip-fit arrangements  300 ,  400  discussed herein can provide increased resistance to inadvertent disengagement of the pulse jet header  124  from the blowpipe  126 . 
     The invention has been described with reference to the example embodiments described above. Modifications and alterations will occur to others upon a reading and understanding of this specification. Examples embodiments incorporating one or more aspects of the invention are intended to include all such modifications and alterations insofar as they come within the scope of the appended claims.