Patent Publication Number: US-2021180490-A1

Title: Systems, devices, and methods for regenerating a particulate filter

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of U.S. patent application Ser. No. 16/077,942, filed Aug. 14, 2018, which is a national phase application under 35 U.S.C. § 371 of International Application No. PCT/IB2017/051087, filed Feb. 24, 2017, which claims the benefit of priority of U.S. Provisional Patent Application No. 62/299,303 filed Feb. 24, 2016, each of which is hereby incorporated herein by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     The present invention relates generally to devices, systems, and methods for use in particulate filter regeneration. 
     2. Description of Related Art 
     Provided by way of example, typical particulate filters are installed in vehicles with diesel engines. Particulate filters require a regeneration process that cleans the filter by incinerating the soot particles that are trapped by the filter. The majority of driving conditions cause fluctuations in load that will not allow the regeneration system to regenerate the filter to a sufficient degree, causing poor performance and in extreme cases, engine shutdown. Reduced exhaust gas temperatures are the main cause of particulate filters with high soot accumulation. Oxidized NO2 regeneration requires exhaust gas temperatures of a minimum of 220 C to generate extremely small amounts of NO2 and thermal regeneration requires exhaust gas temperatures of a minimum of 450 C to regenerate. Particulate filter location also aggravates temperature losses due to the long exhaust pipe length between the engine and the particulate filter. 
     SUMMARY OF THE INVENTION 
     In view of the above-described issues, it is an object of the present disclosure to provide an auxiliary standalone particulate filter regeneration system independent from the vehicles onboard system, and a particulate filter regeneration method capable of raising an exhaust temperature to regenerate a particulate filter by combusting a fuel in the exhaust with the standalone device, where the temperature threshold is sufficient enough to oxidize the particulates accumulated in the filter. 
     An embodiment can include a method for regenerating a particulate filter. A method can comprise: coupling one or more supply lines, each line defining a conduit, to an engine exhaust pipe through at least one of one or more access ports disposed either upstream or downstream of a particulate filter, wherein each supply line is configured to be releasably coupled to the one or more access ports; dispensing a fuel through the one or more supply lines and into the exhaust pipe; and igniting the fuel thereby regenerating the particulate filter. In some particular embodiments, the access port is upstream of the particulate filter. 
     Another embodiment can include a system for regenerating a particulate filter. A system can comprise: a first supply line and a second supply line, each supply line defining a conduit having a first end and a second end and each supply line configured to releasably couple to an exhaust pipe such that the conduit is in fluid communication with the exhaust pipe at the first end; the second end of the first supply line configured to couple to a first reservoir comprising fuel such that the first supply line conduit is in fluid communication with the first reservoir; the second end of the second supply line configured to couple to a second reservoir comprising oxygen such that the second supply line conduit is in fluid communication with the second reservoir; and a connector coupled to the first supply line and the second supply line near their first ends, the connector configured to couple with an access port of the exhaust pipe such that the conduits of the first and second supply lines are in fluid communication with the exhaust pipe. 
     Another embodiment can include a system for regenerating a particulate filter. A system can comprise: a first supply line and a second supply line, each supply line defining a conduit having a first end and a second end and each supply line configured to releasably couple to a particulate filter such that the conduit is in fluid communication with the particulate filter pipe at the first end; the second end of the first supply line configured to couple to a first reservoir comprising fuel such that the first supply line conduit is in fluid communication with the first reservoir; the second end of the second supply line configured to couple to a second reservoir comprising oxygen such that the second supply line conduit is in fluid communication with the second reservoir; and a connector coupled to the first supply line and the second supply line near their first ends, the connector configured to couple either directly or indirectly with the particulate filter such that the conduits of the first and second supply lines are in fluid communication with the particulate filter. In some aspects of this embodiment, the system is configured to regenerate a particulate filter that has been removed from a vehicle. This embodiment of the system can be used, for example, in a method of regenerating a particulate filter comprising removing the particulate filter from a vehicle, connecting the particulate filter on the system, dispensing a fuel through the one or more supply lines and into the exhaust pipe; and igniting the fuel thereby regenerating the particulate filter. The particulate filter can then be replaced on the original vehicle or another vehicle. 
     Another embodiment can include an exhaust pipe fitting. A fitting can comprise a sidewall having a first end and a second end and defining at least a portion of a conduit extending between the first end and the second end, where the sidewall comprises an opening disposed between the first end and the second end that is in fluid communication with the conduit; the first end and the second end each configured to couple to an exhaust pipe or to a particulate filter housing such that the sidewall defines a portion of an engine exhaust path either upstream or downstream of the particulate filter housing. The fitting can further comprise a cover coupled to the sidewall, moveable between an open position and a closed position, and configured to cover the opening when in the closed position 
     Yet another embodiment can include a method of testing a particulate filter regeneration system. Such method can comprise: opening a first valve downstream of a first fuel reservoir, a fuel pressure regulator, a second valve, and a pressure sensor disposed between the first valve and the second valve, where the first valve and the second valve each define a portion of a first conduit; closing the first valve; after closing the first valve, comparing the pressure between the first valve and the second valve to a first threshold value; if the pressure between the first valve and the second valve is below the threshold value, opening the second valve, closing the second valve, comparing the pressure between the first valve and the second valve to a second threshold value. 
     The term “coupled” is defined as connected, although not necessarily directly, and not necessarily mechanically; two items that are “coupled” may be unitary with each other. The terms “a” and “an” are defined as one or more unless this disclosure explicitly requires otherwise. The term “substantially” is defined as largely but not necessarily wholly what is specified (and includes what is specified; e.g., substantially 90 degrees includes 90 degrees and substantially parallel includes parallel), as understood by a person of ordinary skill in the art. In any disclosed embodiment, the terms “substantially,” “approximately,” and “about” may be substituted with “within [a percentage] of” what is specified, where the percentage includes 0.1, 1, 5, and 10 percent. 
     Further, a device or system that is configured in a certain way is configured in at least that way, but it can also be configured in other ways than those specifically described. 
     The terms “comprise” (and any form of comprise, such as “comprises” and “comprising”), “have” (and any form of have, such as “has” and “having”), “include” (and any form of include, such as “includes” and “including”) are open-ended linking verbs. As a result, an apparatus that “comprises,” “has,” or “includes” one or more elements possesses those one or more elements, but is not limited to possessing only those elements. Likewise, a method that “comprises,” “has,” or “includes,” one or more steps possesses those one or more steps, but is not limited to possessing only those one or more steps. 
     Any embodiment of any of the apparatuses, systems, and methods can consist of or consist essentially of—rather than comprise/have/include—any of the described steps, elements, and/or features. Thus, in any of the claims, the term “consisting of” or “consisting essentially of” can be substituted for any of the open-ended linking verbs recited above, in order to change the scope of a given claim from what it would otherwise be using the open-ended linking verb. 
     The feature or features of one embodiment may be applied to other embodiments, even though not described or illustrated, unless expressly prohibited by this disclosure or the nature of the embodiments. 
     Some details associated with the embodiments are described above, and others are described below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following drawings illustrate by way of example and not limitation. For the sake of brevity and clarity, every feature of a given structure is not always labeled in every figure in which that structure appears. Identical reference numbers do not necessarily indicate an identical structure. Rather, the same reference number may be used to indicate a similar feature or a feature with similar functionality, as may non-identical reference numbers. The figures are drawn to scale (unless otherwise noted), meaning the sizes of the depicted elements are accurate relative to each other for at least the embodiment depicted in the figures. 
         FIG. 1  is a block diagram of an exhaust system coupled with an embodiment in accordance with the present disclosure; 
         FIG. 2  is a block diagram of a regeneration system embodiment in accordance with the present disclosure. 
         FIG. 3A  is a block diagram of a regeneration system embodiment in accordance with the present disclosure. 
         FIG. 3B  is a block diagram showing the inputs and outputs of the controller of the regeneration system embodiment shown in  FIG. 3A . 
         FIG. 4A  is a flow chart of a valve check process. 
         FIG. 4B  is a flow chart of a filter regeneration process. 
         FIG. 5  is a perspective, schematic view of a clamping adapter fitting comprising an access port in accordance with an embodiment of the present disclosure. 
         FIG. 6  is a cross-sectioned schematic of a clamping adapter fitting as shown in  FIG. 5  coupled with a connector of a regeneration system embodiment, in accordance with the present disclosure. 
         FIG. 7  is a perspective, schematic view of a flanged adapter fitting comprising an access port in accordance with an embodiment of the present disclosure. 
         FIG. 8( i )  is a side view of a clamping adapter fitting in accordance with an embodiment of the present disclosure. 
         FIG. 8 ( ii ) is a top view of the device of shown in  FIG. 8 ( ii ). 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     Referring now to the figures, and more particularly to  FIG. 1 , shown therein and designated by the reference numeral  100  is an embodiment of a particulate filter regeneration system that is shown coupled to an engine exhaust system  110 . The engine exhaust system shown includes an exhaust pipe  3  that extends from an engine  1  (e.g., a diesel engine) through a turbo charger  2  and through various modules for removing pollutants from the exhaust gas. In the embodiment shown, a diesel oxidation catalyst (DOC)  4  is in fluid communication with the exhaust pipe  3  and is disposed on the downstream side of the turbo charger  2 . Similarly, a selective catalytic reduction system (SCR)  5  is in fluid communication with the exhaust pipe  3  on the downstream side of the DOC  4 , and a particulate filter  7  is in fluid communication with the exhaust pipe  3  and is disposed on the downstream side of the SCR  5 . To facilitate cleaning of the particulate filter with a regeneration system  100 , the exhaust system  110  comprises an adapter fitting  6  disposed on the downstream side of the SCR  5  and either the upstream or downstream side of the particulate filter  7 . The adapter fitting  6  is shown coupled to a particulate filter regeneration system  100 . 
     The regeneration system  100  comprises a first supply line  101  and a second supply line  102  configured to provide one or more fuels and, if needed, an oxidizer, to the exhaust pipe  3  either upstream or downstream of the particulate filter  7 . The system  100  further comprises a connector  8  that is configured to couple with an access port  30  of the exhaust pipe  3  (such as at adapter fitting  6 ) such that the first and second supply lines  101 ,  102  are in fluid communication with the exhaust pipe  3 . The connector  8  is configured to releasably couple with the access port of the exhaust pipe  3  so that the regeneration system  100  can be selectively coupled to and decoupled from the exhaust system, such as through a quick-release mechanism. The access port to the exhaust pipe  3  is located either upstream or downstream of a particulate filter  7  so that when the fuel fed to the exhaust pipe  3  is combusted, the soot or particulate matter on the particulate filter  7  is burned oxidized, e.g., converted to ash a harmless gas(es). With such system, the particulate filter can be selectively regenerated or cleaned. 
     Referring now to  FIG. 2 , a particulate filter regeneration system  100   a  is shown and is a more detailed schematic of the particulate filter regeneration system that is shown in  FIG. 1 . Regeneration system  100   a  comprises supply line  101  (which is shown coupled to a fuel reservoir  20  via valve  21 ) and supply line  102  (which is shown coupled to an oxidizer source  22 ). Each supply line  101 ,  102  can be coupled to a connector  8  that is configured to couple to the access port of an exhaust pipe  3  so that the supply lines  101 ,  102  are in fluid communication with the exhaust pipe  3 . 
     Supply line  101  defines a conduit having a first end  103  and a second end  104  and is configured to transport fuel through the conduit. The supply line  101  is coupled to connector  8 , and during use, e.g., when connector  8  is coupled to an access port of the exhaust pipe  3 , the conduit is in fluid communication with the exhaust pipe  3  at the first end  103 . Second end  104  is coupled to a fuel source, e.g., reservoir  20 . Reservoir  20  can contain a fuel with a relatively low boiling point and high BTU content as compared to other fuel options. For example, in some embodiments, reservoir  20  can contain butane, propane, methane and/or any combination thereof. 
     Along the length of the supply line  101  are several modules for controlling flow and measuring pressure within the supply line  101 . In the embodiment shown, a pressure switch  10  is disposed on the downstream side of reservoir  20 . The pressure switch  10  can be configured to output a signal to indicate whether the reservoir valve is open and/or to indicate whether the pressure within the reservoir  20  is adequate. A fuel pressure regulator  12  is located on the downstream side of the pressure switch  10  and can be configured to reduce the pressure of the fuel flowing from reservoir  20  to a predetermined pressure. A fuel supply valve  11  is located on the upstream side of the fuel pressure regulator  12  and can be configured to block or permit flow through the supply line conduit  101 . A pressure sensor  13  is disposed on the downstream side of the fuel supply valve  11  and can be configured to measure the pressure within the supply line  101 . Another fuel supply valve  14  can be located on the downstream side of the pressure sensor  13 , and another pressure sensor  15  is located downstream of the fuel supply valve  14 . 
     Supply line  102  also defines a conduit having a first end  105  and a second end  106  and is configured to transport a gas, such as air or other oxygen-containing gas. The supply line  102  is coupled to connector  8 , and during use, e.g., when connector  8  is coupled to an access port of the exhaust pipe  3 , the conduit is in fluid communication with the exhaust pipe  3  at the first end  105 . On the other end (second end  106 ), supply line  102  is in fluid communication with the output of an oxidizer gas source, shown here as a compressor  22  outputting compressed air. But it is understood that a reservoir of a pressurized oxygen-containing gas, such as air, could also be used. 
     Along the length of the supply line  102  are modules for controlling flow and measuring pressure within the supply line  102 . In the embodiment shown, a pressure switch  16  is disposed on the downstream side of the compressor  22  and can be configured to output a signal to indicate whether the compressed air source is supplying an adequate air pressure through the conduit. A pressure regulator  17  is disposed on the downstream side of the pressure switch  16  and is configured to reduce the pressure of the air flowing from the compressor  22  to a predetermined pressure. A compressed air supply valve  18  is located on the downstream side of the pressure regulator  17  and can be configured to block or permit flow through the supply line conduit  102 . A pressure sensor  19  is located downstream of the compressed air valve  18  and can be configured to measure the pressure within the supply line  102 . 
     In some embodiments, supply lines  101 ,  102  can be coupled to connector  8  by way of one or more nozzles  23 , which can be coupled to or integrated with the connector  8 . The two supply line ends  103 ,  105  coupled to the connector  8  are in sufficient proximity to each other so that at least a portion of the fuel and the oxygen-containing gas can mix and combustion of the fuel can occur. 
     In addition to the supply lines, system  100   a  comprises an igniter  24  configured to generate a spark within the exhaust pipe  3  in proximity of the fuel and the oxidizer when exiting the first and second supply lines  101 ,  102 . In an embodiment, the spark-generating portion of the igniter  24  can be coupled to the connector  8  such that the igniter  24  is downstream from nozzle  23  when connected to the exhaust system  110 , i.e., closer to the particulate filter than nozzle  23  is. 
     Also coupled to connector  8  can be a temperature sensor  25 . This sensor  25  is configured to measure the temperature, particularly in the exhaust pipe when the connector  8  is coupled to the exhaust pipe. This temperature sensor  25  is disposed relative to the nozzle  23  and igniter  24  so that the sensor can detect a temperature rise in the proximity of the fuel source and/or igniter  24 , indicating whether the fuel injected into the exhaust system  110  actually combusted during an ignition cycle. 
     Referring now to  FIGS. 3A and 3B , shown therein and designated by the reference numeral  100   b  is a second embodiment of the present regeneration system. This embodiment is similar to that shown in  FIG. 2  except that it further comprises a system controller  9  and the modules of supply line  101  and  102  and those coupled to connector  8  are configured to communicate with controller  9 . For example, the pressure sensors  13 ,  15 , and  19  are configured to output a signal indicating pressure to the controller  9 . Similarly, temperature sensor  25  is configured to output a signal indicating pressure to the controller  9 . Valves  11 ,  14 ,  18 , and/or  21  can be configured to close and open via communications from the controller  9 . Controller  9  can also be configured to cycle on and off air compressor  22 . The igniter  24  can be configured to actuate via communication from the controller  9 . In the embodiment shown, igniter  24  comprises an ignition coil  24   a  and an ignition plug  24   b . Ignition plug  24   b  (e.g., spark plug) is coupled to connector  8  and in proximity of nozzle  23 . Other devices for creating the necessary heat to cause ignition of the fuel include a glow plug 
     System controller  9  can be provided with a data-processing system comprising a microprocessor  9   d  configured to transmit instructions or receive readings from the various modules of the system  100   b  for implementation of a valve safety verification process and/or a filter regeneration process. The system  100   b  can further be equipped with a memory  9   e , especially a non-volatile memory, allowing it to load and store a software program, that, when executed in the microprocessor  9   d , allows the valve safety verification process and/or the filter regeneration process to be implemented. This non-volatile memory  9   e  can be, for example, a ROM (read-only memory). Furthermore, the system controller  9  comprises a memory  9   f , especially a volatile memory, allowing data to be stored during the execution of the software package and the implementation of the process. This volatile memory  9   f  may be, for example, a RAM or EEPROM (“random access memory” or “electrically erasable programmable read-only memory”, respectively). 
     In some embodiments, the system controller  9  can be configured to selectively and independently open and close valves (e.g.,  11 ,  14 , and/or  18 )(module  9   c  in  FIG. 3B ). In some embodiments, the system controller  9  can be configured to execute a safety verification process (module  9   a  in  FIG. 3B ) and/or a regeneration process (module  9   b  in  FIG. 3B ). 
       FIG. 4A  depicts an embodiment of a safety verification process with system controller  9  configured to executing one or more steps of this process. Beginning at a step S 1 , a sensor function verification process of all of the system&#39;s sensors will be performed. This process comprises validating pressure switches  10 ,  16  are above a threshold value, e.g., above 30 psi, determining if pressure sensors  13 ,  15 ,  19  are within threshold values, e.g., less than 0.5 psi, and determining if temperature sensor  25  is within a threshold value, e.g., less than 75° C. If the sensors do not relay an appropriate value, an error code with information pinpointing a failure can be generated. Such error code and/or information pinpointing the failure can be displayed on a screen, which is part of a user interface system  40 . 
     If the sensors are verified to be operational, at a step  2 , a valve interlock test is initiated to determine the integrity of the valves. Specifically, at a step S 3 , the fuel supply valve  14  is cycled open to relieve any pressure that may be contained between valves  11  and  14  during start up and then is cycled closed. At a step S 4 , a pressure reading is obtained by the pressure sensor  13  to determine if fuel supply valve  11  is leaking. For example, if the pressure rises above atmospheric, the test fails (e.g., valve  11  may be leaking) and an error code is generated. At a step S 5 , the fuel supply valve  11  is cycled open to pressurize the conduit of supply line  101  between fuel supply valves  11  and  14  and then is cycled closed. At a step S 6 , a pressure reading is obtained from pressure sensor  13  to determine if fuel valve  14  is leaking. If the pressure drops below a threshold value, the test fails. In some embodiments, this threshold value is the actual pressure of the regulator  12  or within a certain percentage thereof (e.g., 5% of the regulated pressure). If the test fails, the controller  9  can communicate with the user interface system  40 , generating and displaying an error code and/or returning to a start menu. 
     At a step S 7 , the fuel supply valves  11  and  14  are both cycled open. At a step S 8 , a pressure reading is obtained from pressure sensors  13  and  15  to determine the integrity of the fuel pressure regulator  12  is within the threshold values. This threshold value can be the same as the previous value, e.g., the actual reservoir pressure or a minimum acceptable pressure for the reservoir. If the pressure is below or above the threshold value, the test fails and returns to the start menu with an error code. 
     At a step S 9 , the fuel supply valves  11  and  14  are cycled closed. At a step S 10 , the compressed air supply valve  18  is opened and the air compressor  22  is cycled on. At a step S 11 , a pressure reading is obtained from pressure sensor  19  to determine the integrity of the compressed air pressure regulator  17  is within a threshold value. If the pressure is below or above the threshold value, the test fails and returns to the start menu with an error code. 
     At a step S 12 , the compressed air supply valve  18  is closed and air compressor  22  is cycled off. At a step S 13 , if all of the above test complete without setting errors, the safety verification process is complete. In some embodiments, the system may then move on to the start of the regeneration process. 
       FIG. 4B  depicts an embodiment of a filter regeneration process with processor  9  configured to execute one or more steps of this process. the filter regeneration process can begin at a step S 14  where the compressed air valve  18  opens and the air compressor  22  is actuated to initiate the purge cycle for a predetermined amount of time (e.g., 5 seconds to 10 minutes), and the compressed air valve will remain open through step S 15 . At a step S 15 , the fuel supply valves  11  and  14  are opened. Moreover, pressure sensors  15 ,  19  and temperature sensor  25  will be monitored, and the igniter  24  will be actuated for a predetermined amount of time. At a step S 16 , a continuous measurement of the temperature sensor  25  is obtained to determine if the temperature within the exhaust pipe is above a threshold value or increased a certain amount within a set interval of time. The temperature reading helps determine combustion throughout the entire regeneration period. If temperature drops below a threshold value, the regeneration process fails and returns to the purge sequence, step S 14 . The system can attempt to reignite again (up to 3 times in some embodiments) before generating an error code and/or returning to the start menu. At a step S 17 , the regeneration process is allowed to run for a predetermined amount of time. The amount of time can depend on a number of factors that can be taken into account when determining the time, such factors can include, e.g., the vehicle make, vehicle model, vehicle year, the engine make, the engine model, the engine year, the filter type, the amount of particulates in the particulate filter, the amount of time since the filter was previously regenerated, size or mass of the filter to be regenerated; the BTUs generated by the system  100 , and the moisture content in the exhaust system. In some embodiments, the regeneration process can run from 2 minutes to 3 hours or more (e.g., 2, 3, 4, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180 minutes, or any time therebetween). In some embodiments, the air to fuel ratio dispensed can be between 20:1 and 10:1 (e.g., 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1 20:1, or any range therein). System  100  can be configured to provide either a variable or constant output of BTUs. A variable BTU system would allow for comparable burn times despite differences in the filters to be cleaned. A variable system can comprise electronic regulators or electronic switching valves for regulators  12  and  17 . In some embodiments, the electronic switching valves can be driven by a pulse width modulation from the controller  9 ,  9   c . The variable BTU system could be configured to generate a higher amount of BTUs at the beginning and reduce the amount of BTUs once the filter reached a desired regeneration temperature. Such temperature can be estimated from temperature sensor  25 . 
     To terminate the combustion cycle, at a step S 18 , the fuel supply valves  11  and  14  closed. At a step S 19 , the post purge process begins. The compressed air supply valve  18  remains open and air compressor  22  remains on for a predetermined amount of time (e.g., 5 seconds to 10 minutes), thus completing the filter regeneration process. 
     Referring now to  FIGS. 5 and 6 , shown therein and designated by the reference numeral  6   a  is an embodiment of an adapter fitting.  FIG. 5  shows a perspective view of only adapter fitting  6   a , and  FIG. 6  shows a cross-section schematic of adapter fitting  6   a  coupled to connector  8 . Adapter fitting  6   a  is a clamp-style adapter fitting. Fitting  6   a  comprises a sidewall  31   a  having a first end  32   a  and a second end  33   a  and defining at least a portion of a conduit  34   a  extending between the two ends  32   a ,  33   a . The sidewall  31   a  comprises an opening/access port  30   a  disposed between the two ends  32   a ,  33   a  that is in fluid communication with the conduit  34   a . The clamp-style adapter fitting  6   a  is configured to clamp around an exhaust pipe (e.g., exhaust pipe  3 ) such that the exhaust pipe extends through the conduit  34   a . The fitting  6   a  can comprise clamp lock  35   a  coupled to the sidewall  31   a  and configured to maintain the sidewall in a cinched/compressed position around the exhaust pipe. 
     In some embodiments, the adapter fitting  6   a  may comprise a releasable lock  36   a  that is adjacent to or defines at least a portion of the access port  30   a . Locking mechanism  36   a  can be coupled to or integral with the sidewall  31   a  and is configured to couple with the connector  8  of filter regeneration system  100   a ,  110   a  ( FIGS. 2 and 3A ). Releasable locking mechanism  36   a  can be any variety of devices for securing two objects together, such as a screw-threaded type; bayonet-type mount, or a breech-lock type (friction type). 
     In some embodiments, the adapter fitting  6   a  can comprise a cover (not shown) rotatably or slideably coupled to the sidewall so that it can move between a closed position and an open position to selectively cover and uncover the access port. In some embodiments, the cover can be biased toward the closed position. For example, in some embodiments, the cover is coupled to the sidewall via a hinge that is biased toward the closed position. 
     Referring now to  FIG. 7 , shown therein and designated by the reference numeral  6   b  is another embodiment of an adapter fitting. Adapter  6   b  is a flanged-type adapter fitting. Adapter  6   b  is the same as adapter fitting  6   a  except the structure used to couple with exhaust pipe is a flanged end  33   b  and does not have a clamping mechanism or a releasable locking mechanism. 
     Referring now to  FIG. 8 , shown therein and designated by the reference numeral  6   c  is another embodiment of an adapter fitting. Adapter fitting  6   c  is a clamp-style adapter fitting similar to that shown in  FIG. 5  except that a sidewall  31   c  defines only a portion of conduit  34   c  and chain  40   c  is coupled to sidewall  31   c  to define another portion of the conduit. A portion of lock  35   c , namely pin  39   c , also defines a portion of conduit  34   c . The sidewall  31   c  comprises an opening/access port  30   c  disposed between the two ends  32   c ,  33   c  of sidewall  31   c  that is in fluid communication with the conduit  34   c . The clamp-style adapter fitting  6   c  is configured to clamp around an exhaust pipe (e.g., exhaust pipe  3 ) such that the exhaust pipe extends through the conduit  34   c . The fitting  6   c  can comprise clamp lock  35   c  coupled to the sidewall  31   c  and configured to maintain the sidewall  31   c  and chain  40   c  in a cinched/compressed position. In the embodiment shown, clamp lock  35   c  comprises a knob  38   c  defining a threaded receptacle configured to engage a threaded pin  39   c  that is coupled to chain  40   c  at an end opposite from where the chain is coupled to sidewall  31   c.    
     In some embodiments, the adapter fitting  6   c  may comprise a releasable lock  36   c  that is adjacent to or defines at least a portion of the access port  30   c . Lock  36   c  can be coupled to or integral with the sidewall  31   c  and is configured to couple with the connector  8  of filter regeneration system  100   a ,  110   a  ( FIGS. 2 and 3A ). Releasable lock  36   c  can be any variety of devices for securing two objects together, such as a screw-threaded type; bayonet-type mount, or a breech-lock type (friction type). In the embodiment shown, lock  36   c  comprises a resilient tab mounted to sidewall  31   c . An end of tab  31   c  is disposed above opening  30   c  and is configured to fit into a notch of, e.g., connector  8 , when the connector extends through the opening and slidably release from the notch when the connector  8  is intentionally pulled from the opening. 
     Some embodiments include a method of testing a particulate filter regeneration system. Referring to  FIG. 2 , valve  14  can be cycled opened and closed. (This cycling of valve  14  may occur after both valves  11  and  14  have been cycled open and closed.) After closing, the pressure at sensor  13  in the region between the two valves  11 ,  14  is compared to atmospheric pressure. If this pressure is substantially equal to atmospheric pressure, the functioning of valve  11  is verified. 
     To verify the function of valve  14 , valve  11  is opened (while valve  14  remains closed) and the pressure between valve  11  and valve  14  is compared to a second threshold value. In some embodiments, the second threshold value is the pressure at which regulator  12  is configured to dispense the fuel in reservoir  20 . If this pressure remains above or maintains a pressure substantially the same as the second threshold value, the valve  14  is verified to be functioning properly. 
     To verify the function of regulator  12 , both valves  11 ,  14  are cycled open and the pressure between valves  11 ,  14  or after valve  14  is compared to a third threshold value. In some embodiments, the third threshold value is the pressure at which regulator  12  is configured to dispense the fuel in reservoir  20 . In some embodiments, the third threshold value is equal to the second threshold value. If the difference between this pressure and the third threshold value is between 1% to 25% (e.g., 1%, 5%, 10%, 15%, 20%, or 25%), the regulator  12  is verified to be functioning properly. 
     To verify the function of gas pressure regulator  17 , valve  18  upstream of pressure sensor  19  and downstream of air compressor  22  and regulator  17  is opened, and the pressure downstream of valve  18  (e.g., at sensor  19 ) is compared to a fourth threshold value. In some embodiments, the fourth threshold value is the pressure at which regulator  17  is configured to dispense the oxygen-containing gas from compressor  22 . If the difference between this pressure and the fourth threshold value is between 1% to 25% (e.g., 1%, 5%, 10%, 15%, 20%, or 25%), the regulator  17  is verified to be functioning properly. (The compressor  22  is in communication with the atmosphere, which is a reservoir for the purpose of this disclosure.) 
     The regeneration cycle can then be initiated. In some embodiments, a particulate filter can be regenerated without removing it from the exhaust system. In other embodiments, the particulate filter can be removed from the exhaust system and placed in housing configured to contain a gaseous substance and withstand the combustion reaction. The housing is also configured to couple to connector  8 . 
     To execute a particulate regeneration cycle, after supply lines  101 ,  102  are coupled to a housing containing a particulate filter or to an engine exhaust pipe at a location either upstream or downstream of a particulate filter (such as through an access port), a fuel is dispensed through supply line  101  and into the housing or the exhaust pipe, and an oxygen-containing gas is dispensed through supply line  102 . The fuel (e.g., butane, propane, methane, or some combination thereof) and the oxygen-containing gas can be dispensed for a predetermined amount of time to fill the housing or exhaust system in the vicinity of the filter. After such time, the fuel can be ignited, such as by generating a spark with igniter  24  in the vicinity of dispensed fuel. This causes the fuel to combust, thereby regenerating the particulate filter. As stated previously, the fuel to gas ratio can be between 20:1 and 10:1. This combustion reaction can be maintained (e.g., by maintaining a flow of fuel and gas) for 2 minutes to 3 hours or more (e.g., 2, 3, 4, 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180 minutes, or any time therebetween). 
     In order to verify that combustion has occurred, the temperature within the engine exhaust system is measured. If the temperature is above a threshold, such as 100° C., combustion is confirmed. 
     The above specification and examples provide a complete description of the structure and use of illustrative embodiments. Although certain embodiments have been described above with a certain degree of particularity, or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the scope of this invention. As such, the various illustrative embodiments of the methods and systems are not intended to be limited to the particular forms disclosed. Rather, they include all modifications and alternatives falling within the scope of the claims, and embodiments other than the one shown may include some or all of the features of the depicted embodiment. For example, elements may be omitted or combined as a unitary structure, and/or connections may be substituted. Further, where appropriate, aspects of any of the examples described above may be combined with aspects of any of the other examples described to form further examples having comparable or different properties and/or functions, and addressing the same or different problems. Similarly, it will be understood that the benefits and advantages described above may relate to one embodiment or may relate to several embodiments. 
     The claims are not intended to include, and should not be interpreted to include, means-plus- or step-plus-function limitations, unless such a limitation is explicitly recited in a given claim using the phrase(s) “means for” or “step for,” respectively.