Improved system and method for maintenance of diesel particulate filters

Abstract

The invention relates to an improved system and accompanying method for maintenance of diesel particulate filters, using a combination of thermal regeneration and pneumatic / pressurized air stream cleaning.

Description

[0001] IMPROVED SYSTEM AND METHOD FOR MAINTENANCE OF DIESEL PARTICULATE FILTERS

[0002] FIELD OF INVENTION

[0003] The present invention relates to a system and a method for Diesel Particulate Filter (DPF) maintenance.

[0004] BACKGROUND

[0005] Diesel Particulate Filters (DPF) are devices found in the exhaust system of diesel- powered vehicles, designed to remove and capture particulate matter from the exhaust gases before they are released into the environment. This filtration is crucial for reducing air pollution and meeting environmental regulations regarding vehicle emissions. Maintaining and cleaning a DPF is essential as the filter can become clogged over time, which can impair its function, reduce engine performance, increase fuel consumption, and potentially lead to costly repairs. Regular maintenance ensures the DPF operates efficiently, and thereby extends the life of both the DPF and the corresponding engine, while also ensuring the vehicle remains environmentally compliant.

[0006] Over time, the DPFs become more and more saturated by the particulate matter that they remove, primarily soot, which consists of a fine black or dark brown powder, comprising mainly of carbon particles that result from the incomplete combustion of diesel fuel. As the filters become clogged, their functionality degrades until it reaches a point wherein the filter must be cleaned (or replaced entirely).

[0007] During a process called thermal regeneration, the soot in the filters is ignited and turned to ash by raising the DPF temperature. To flush out the remaining ash traditional methods employ air and / or water, yet these methods have downsides. Water-based cleaning can be thorough but risks damaging the DPF or potentially lead to corrosion. Air-based cleaning methods, while effective in removing loose ash and particulates, often do not adequately remove all particulate, impairing the DPF efficiency, especially in the case where soot has compacted or bonded to the filter material. This is especially an issue for DPFs in the maritime sector, where DPFs have a more complex shape and removing ash and soot is therefore more challenging. CN 110327698 discloses a type of regenerated off-line diesel particulate trap device and its regenerated off-line methods. It describes a diesel particulate filter regeneration device, comprising a furnace and a high-voltage pulsed air assembly, and a high-voltage pulsed air assembly, which are installed on the furnace, and a high-voltage pulsed air assembly is used to spray high-voltage pulsed gas into the furnace combustion chamber. The DPF filter is placed in the furnace, and the high- voltage pulsed gas is sprayed toward the gas outlet by the high-voltage pulsed air assembly, accelerating the combustion of charcoal particles, reducing the regeneration temperature and time, and improving energy consumption efficiency.

[0008] Even more importantly, DPF cleaning in maritime applications, requires the vessels to remain docked for a prolonged period of time, which is highly undesirable, both in terms of cost, as well as in terms of occupied space, and risk for other vessels. As such, reducing down-time by increasing cleaning speed and / or efficiency is a crucial aspect in this sector.

[0009] None of the existing systems and processes provide for a sufficiently fast and effective result in cleaning the DPFs, and improvements are sought upon the existing technologies.

[0010] DESCRIPTION OF FIGURES

[0011] Figure 1 shows an schematic representation of a maintenance system according to an embodiment of the invention.

[0012] DETAILED DESCRIPTION OF THE INVENTION

[0013] Unless otherwise defined, all terms used in disclosing the invention, including technical and scientific terms, have the meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. By means of further guidance, term definitions are included to better appreciate the teaching of the present invention.

[0014] As used herein, the following terms have the following meanings:

[0015] The term "soot" refers to a fine black or dark brown powder consisting of carbon particles that result from the incomplete combustion of diesel fuel. The term "pneumatic shock waves" refer to shock waves of compressed air, generated by a pneumatic device, wherein the compressed air is used for cleaning. This is achieved by high-pressure air blasts to dislodge and remove trapped particular matter, in this case soot.

[0016] In a first aspect, the current invention concerns a system for DPF maintenance, comprising an oven suitable for receiving one or more DPFs, said oven being configured for the thermal regeneration of received DPFs; a pneumatic device utilizing pneumatic shockwaves for cleaning filters of DPFs and / or a pressurized airflow generating device (PAGD) (3) configured for cleaning filters of the thermally regenerated DPFs via one or more pressurized air streams; a power supply configured to generate power for the oven, whereby the system is characterized by the fact that the pneumatic device and / or the PAGD is mounted on a vibration table via a shock-absorbing connection, wherein said vibration table is suitable for receiving the thermally regenerated DPFs and is configured for vibrating the received DPFs.

[0017] Before the maintenance process the DPFs are loaded with soot and / or ash. The initial thermal regeneration step will oxidize the soot and convert it to a non-toxic gas. The pneumatic device and / or the PAGD can be employed to blow the ash out of the DPF, and by simultaneously vibrating the DPF, even ash will be dislodged and removed by the pneumatic shock wave and / or pressurized air streams and vibrations from the vibration table. The combination of vibrations and shock waves will result in a process that only requires 5 minutes or less, as opposed to conventional technologies used, where the cleaning takes at least 20 minutes.

[0018] The pneumatic device and / or PAGD can be controlled, in terms of frequency and amplitude of the shock waves it generates. Specifically, the pneumatic device and / or PAGD is furthermore configured for controlled shock waves that are focused on a particular zone or target, namely the DPF, in order to maximize efficiency, as opposed to general shock waves. By creating rapid pressure shock waves within the filter, the remaining ash particles, already partially loosened after the thermal regeneration step, are effectively dislodged and removed further. The remaining soot particles, if any after the thermal regeneration, will be removed by the vibrations and shock waves combined.

[0019] Vibrations must be uniformly distributed throughout the filter in order to effectively dislodge all particulate matter within a DPF. A vibration table is ideally suited for this purpose, as it delivers planar vibrations that propagate uniformly through the DPF. Vibration elements of smaller size can be used, yet they form a more localized vibration source, leading to a distribution pattern more heavily dependent on the structure of the DPF, making them less effective for dislodging soot, especially if the DPF size is bigger and / or the shape more complex. The vibrations can be regulated by frequency and amplitude so that all DPFs, all seizes and weights, can be effectively cleaned by the system according to the invention.

[0020] In a preferred embodiment, the PAGD comprises one or more air knives, which are configured for generating a substantially uniform sheet of laminar airflow at high pressure, allowing it, similar as for the pneumatic shock waves, to 'wash' away particles loosened by the vibrations, aside from loosening the particles themselves.

[0021] In a most preferred embodiment, no pneumatic device is used and only a PAGD is used, preferably comprising air knives.

[0022] In alternative embodiments, no PAGD is used in the system and only a pneumatic device is used.

[0023] In some embodiments, both a PAGD and a pneumatic device is used. In some variations, the PAGD precedes the pneumatic device, while in others, the pneumatic device precedes the PAGD. Preferably, the PAGD comprises one or more air knives.

[0024] In a preferred embodiment of the invention the DPF maintenance system further comprises a catalyst testing machine for testing an SCR (Selective Catalytic Reduction) unit that can be used in conjunction with the DPF in many applications. By measuring the efficiency of catalysts in the SCR, it can be determined how functional the SCR still is, and whether it needs to be cleaned, rejuvenated, repaired or replaced.

[0025] Most importantly however, the catalytic activity / functionality of the SCR unit is evaluated under simulated operating conditions in a controlled laboratory environment. This involves exposing the SCR unit to a gas stream containing representative diesel exhaust components, including soot, hydrocarbons, carbon monoxide, and nitrogen oxides (NOx).

[0026] One of the primary functions of the catalyst is to facilitate the reaction of NOx with a reductant, such as urea or ammonia. In order to ensure efficiency, the catalytic performance of the SCR unit needs to be tested at regular intervals, in order to be able to rejuvenate, regenerate or replace the catalyst module of the SCR in time. In another preferred embodiment of the invention the catalyst testing machine is suitable for simultaneously testing multiple SCRs, speeding up the maintenance process.

[0027] In another preferred embodiment of the invention, the power supply is a diesel generator, and the exhaust of the diesel generator is connected to the catalyst testing machine, whereby the catalyst testing machine is configured to use the exhausted gasses from the diesel generator for SCR unit. This will increase the energy efficiency of the maintenance system, and make positive use of a waste stream, using it to expose the SCR to a gas stream comprising soot.

[0028] In another preferred embodiment of the invention, the pneumatic device and / or PAGD comprises one or more magnets. With these magnets metals, present in the DPFs, can be collected from the exhaust of the pneumatic device and / or PAGD.

[0029] In another preferred embodiment, the system comprises a plurality of loading units suitable for receiving a plurality of DPFs, and for fixating the DPFs to the loading unit. The loading units are suitable for reception in the oven, preferably in a way that allows multiple loading units to be received at ones, for instance in multiple levels and / or rows / column. This way, oven efficiency is increased, and cleaning speed is improved. The dedicated loading units simplify transporting the DPF and increase safety thereof during transport between the separate units (to the oven, to the pneumatic device and / or PAGD, to the catalyst testing unit, ...).

[0030] Preferably, the loading units can comprise two or more variations, suitable for receiving DPFs of different size. For instance, DPFs typically have a 12 inch diameter, or 9.5 inch, or 17.5 inch. Other types of DPFs can be rectangular, square or other shapes, for which dedicated loading units can be provided. By providing loading units for each, the oven can be supplied more efficiently, while ensuring that the DPFs are held reliably.

[0031] Preferably, the loading units can be coupled to a transport unit, which comprises a plurality of wheels or rollers, to allow easy movement of the loading unit. Usually, the loading unit is then removed from the transport unit and moved into the oven without the transport unit.

[0032] In another preferred embodiment, the system comprises a weighing station, where the DPF is weighed after thermal regeneration and (pneumatic) cleaning to determine the mass (of soot and ash) removed, by comparison to the weight before thermal regeneration. This data is preferably stored associated to the DPF, via an identifier, in a database. In a preferred embodiment, humidity and / or temperature is recorded in order to more accurately determine the removed mass.

[0033] In another preferred embodiment, the system comprises an engraving station or marking station, wherein the DPF is provided with visual markers (engravings, preferably) representing information regarding the cleaning cycle. This information may comprise the date of cleaning, an identifier to access a database where the cleaning cycle data is stored, and / or others. Most preferably, the information that is collected for a cleaning cycle is the weight of deposits removed during the cycle, preferably also with the date of cleaning. Preferably, the engraving station is a laser engraving station.

[0034] In a most preferred embodiment, the visual markers are in the form of a two- dimensional machine-readable visualization, for instance a QR code, barcode, and the likes thereof, providing a link or access to the digitally stored information.

[0035] In another preferred embodiment of the invention, the pneumatic device further comprises a monitoring device for monitoring a backpressure generated by the DPF. From this backpressure, DPF status can be determined. When a predetermined minimal backpressure threshold is reached, the DPF is considered to be clean.

[0036] In another preferred embodiment, the pneumatic device and / or PAGD comprises a plurality of preprogrammed settings, which can be implemented depending on the DPF characteristics. These characteristics can be size, type, shape and (estimated) level of deposit accumulation, as well as other characteristics. Based on this, a suiting setting is used for treating the DPF optimally. Preferably, the setting choice is performed automatically, by recognition of the DPF, for instance via a visual marker on the DPF which is scanned before further processing.

[0037] In another preferred embodiment, the oven is equipped with forced ventilation which will ensure fresh air inside in the oven. This will result in extra oxygen particles to promote oxidization of the soot particles. After completing a cleaning program, it can be used to cool the oven down..

[0038] In another preferred embodiment, the pneumatic device and / or PAGD is provided with a plurality of sensors capable of detecting pressure, temperature and / or other characteristics, in order to optimize the process, by lengthening or shortening the procedure as necessary and / or adjusting certain settings. In a second aspect the current invention concerns a method for maintaining DPFs, comprising thermally regenerating DPFs using an oven; cleaning said thermally regenerated DPFs with pneumatic shock waves via a pneumatic device and / or with one or more pressurized air streams via a pressurized airflow generating device (PAGD); characterized in that the method comprises a step of: vibrating the thermally regenerated DPF during the step of cleaning the thermally regenerated DPF with pneumatic shock waves and / or with the pressurized air streams, and in that said pneumatic device and / or PAGD is mounted on a vibration table via a shockabsorbing connection, wherein said vibration table is suitable for receiving the thermally regenerated DPFs and wherein the method comprises a step of vibrating the received DPFs with the vibration table.

[0039] Combining thermal regeneration with pneumatic shock waves and / or pressurized air streams alone will in most cases not remove all the particulates from the DPF, especially concerning DPFs with more complex shape, where more areas are hard to reach by a pneumatic shock wave or air streams. Additional vibrations will dislodge compacted ash from the hard-to-reach areas and allow a pneumatic shock or pressurized air stream wave to clean the DPF more effectively. Furthermore, using pneumatic shock waves and / or pressurized air streams only in combination with vibrations might remove particle deposits from the PDF, but it will not remove the most hardened and compacted soot. A preceding step of thermal regeneration will oxidize the soot and convert it into gas, which is more easily removed by a pneumatic shock wave or pressurized air stream. It is therefore that these three steps together will effectively clean DPF filters of varying shapes and sizes, making this method ideal for cleaning maritime DPFs, but not limited thereto. It is the general objective of the present invention to serve in cleaning all types of DPFs, regardless of application.

[0040] In a preferred embodiment, the PAGD comprises one or more air knives, which are configured for generating a substantially uniform sheet of laminar airflow at high pressure, allowing it, similar as for the pneumatic shock waves, to 'wash' away particles loosened by the vibrations, aside from loosening the particles themselves.

[0041] In some embodiments, no pneumatic device is used and only a PAGD, preferably air knives, is used.

[0042] In alternative embodiments, no PAGD is used in the system and only a pneumatic device is used. In some embodiments, both a PAGD and a pneumatic device is used. In some variations, the PAGD precedes the pneumatic device, while in others, the pneumatic device precedes the PAGD. Preferably, the PAGD comprises one or more air knives.

[0043] In another preferred embodiment, the method comprises capturing metal deposits that are removed during the cleaning process and analyzing said metals for the presence of metals, in particular of iron and / or steel, which can originate from grinding and welding of the exhaust lines. Furthermore, current DPF cleaning techniques primarily focus on removing particulate matter without utilizing the process to gather critical diagnostic data about the corresponding engine's health. Analyzing the metals present in the DPF soot can show early signs of wear in the exhaust pipes due to grinding and drilling, which can lead to a decrease in efficiency of the SCR (Selective Catalytic Reduction). This can significantly limit the number of required separate diagnostic checks, reducing maintenance costs and operational downtime — particularly important in commercial operations like trucking and shipping. The integration of DPF maintenance and broader engine diagnostics fosters a preventive maintenance schedule, where problems are addressed prematurely, allowing a more efficient fleet management.

[0044] In another preferred embodiment, the method comprises weighing the DPFs before and after maintenance to determine the amount of soot removed; and using the estimated amount of particles removed as an indicator for engine load diagnosis. Abnormal amounts of soot present in the DPF might indicate a problem with the air intake, or be a sign of malfunctioning fuel injectors or abnormal oil consumption.

[0045] In another preferred embodiment, the method further comprises a step of backpressure monitoring in the pneumatic device for DPF health performance analysis. Excessively low backpressure resulting from a pneumatic shock wave through the filter could signal cracks in the DPF. Such cracks compromise filter efficiency, diminish engine performance, and may cause dangerously high temperatures within the exhaust system. Conversely, excessively high backpressure suggests a clogged DPF. This condition increases engine backpressure, which in turn can elevate fuel consumption, decrease engine performance, and potentially damage valves and cylinders.

[0046] In another preferred embodiment, the method further comprises the steps of recording cleaning data and catalyst testing data, said data comprising DPF weight, ambient temperature, humidity, DPF surface temperature and DPF catalyst efficiency; storing said data in a database and using the stored data for future reference and analysis.

[0047] A complete maintenance history of a DPF element allows for a tailored maintenance process and schedule, optimizing both DPF performance and lifespan. Similarly, such a dataset reflects engine performance and malfunctions, providing valuable insights that can be used for performance optimization. This is of significant influence in the commercial shipping and trucking industries, where efficiency and reliability are critical.

[0048] In a preferred embodiment, each DPF is engraved with information regarding the cleaning cycle at the end thereof. Said information can for instance be an identifier that allows to the full data on the cleaning cycle, for instance via a dedicated app or website. The full data will typically comprise information on the weight of the DPF before and after cleaning (or more specifically, the weight of the soot that is removed). The information engraved may comprise the date of the cleaning cycle, as well as other information. Most preferably however, the DPF is engraved with an optical, machine-readable identifier, such as a barcode, QR code and the likes thereof, which provide access to the actual information, which is stored in a central database.

[0049] The invention is further described by the following non-limiting examples which further illustrate the invention, and are not intended to, nor should they be interpreted to, limit the scope of the invention.

[0050] The present invention will be now described in more details, referring to examples that are not limitative.

[0051] EXAMPLES

[0052] With as a goal illustrating better the properties of the invention the following presents, as an example and limiting in no way other potential applications, a description of a maintenance system according to the invention is described below:

[0053] The system as shown in Figure 1 comprises multiple stations, that are sequentially placed to improve the process flow of maintenance. A first station represents an intake position, where the filters are weighed, visually inspected and submitted to an initial backpressure test. At this point, the DPFs are also engraved with unique identifiers, via a laser engraving unit (10), which provides a link to a database in which the data that is stored for said DPF. The data can comprise weights before and after cleaning (and optionally in between), time of cleaning and additional info.

[0054] Following this step, the DPF is then inspected. This is achieved by mounting it onto an inspection table, which couples an opening to the DPF, wherein a fan is provided under the opening. The fan will generate an airflow, through the DPF, and the pressure drop is measured over the DPF, which provides a baseline reading on how "dirty" the DPF is. Additionally, a lighting unit, typically an LED light, is provided in the hole, to generate a light beam through the DPF, which allows a visual inspection of the DPF to determine whether cracks or other physical damage is present.

[0055] After this, the DPF is weighed in dirty condition.

[0056] In a next step, the DPFs (1) are provided onto loading units (7), typically in the form of pallets. These loading units (7) are shaped to receive the DPFs (1), and preferably at least partly affix them to the loading unit (for instance, via grooves in which the DPF fits). Depending on the size or type of DPF (1), multiple loading units (7) can be provided to ensure they are held securely. In Figure 1, three separate loading units (7) are provided for different-sized DPFs (1), in this case 12 inch, 9.5 inch and 17.5 inch (from left to right on the figure).

[0057] The loading units (7) are designed to receive multiple DPFs, and can be mounted on top of a transport unit (8) with a number of wheels, allowing the DPFs (1) to be moved over the cleaning facility from an intake point, to the oven (2). At the oven

[0058] (2), the transport unit (8) can decouple the loading unit (7) which is moved entirely, with the DPFs (1) thereon, into the oven (2), where the DPFs (1) are thermally regenerated, typically at a temperature around 600°C (although variations occur), to initiate combustion of the soot particles that are clogging the DPF. The heating process typically takes between 4 and 8 hours, preferably between 5 and 7 hours, such as 6 hours, but in some cases, longer periods can be used (or multiple shorter cycles), for instance in case of high soot accumulation levels in the DPFs.

[0059] In the example, the oven (2) has a volume of around 2000 liters, to allow regeneration of multiple DPF batches at once (for instance, in multiple levels), in particular of at least 24 separate 12 inch DPFs, and has an average power of 80 kW. This oven is provided with power by a diesel generator (5).

[0060] After the thermal regeneration step, the DPFs (1) are removed from the oven (1) and weighed again, in order to determine how much soot has been oxidized in the oven (2).

[0061] After weighing, the DPFs (1) are moved to the pneumatic device (3) and / or PAGD

[0062] (3). The movement of the DPFs (1) can again be performed by mounting the loading unit (7) holding the DPFs onto the transport unit (8), or can be performed individually.

[0063] The DPFs are mounted into the pneumatic device (3) and / or PAGD (3), and subjected to compressed air waves ("pneumatic shock waves") or pressurized air streams, where the high-speed and abrupt pressure differences dislodge the combusted soot particles from the DPF. During the pneumatic shock wave treatment or pressurized air stream treatment, the DPF is furthermore subjected to vibrations, via a vibration table (4), thereby further loosening and dislodging the soot particles by subjecting the DPF both to the compressed air waves from the pneumatic device (3) and / or to the pressurized air streams of the PAGD (3), and the vibrations of the vibration table (4).

[0064] During this cleaning step, the dislodged ash and other particles can be collected for further analysis, as can be seen in Figure 1 by the recipient below the DPF. One of the aspects to be analyzed, is the amount of metal particles present in the removed particles, as well as the total weight of ash that is removed. The metallic particles are usually separated via one or more magnets, allowing them to be weighed separately, thus giving a view on the amount of "metal" removed from the filters, and the amount of soot removed from the filters.

[0065] After the pneumatic shock wave and / or pressurized air stream and vibration cleaning, the DPFs (1) are again inspected, potentially at the same inspection table as during the initial inspection, although a separate inspection table can be used. Again, the DPF is mounted onto an opening with a fan, to determine the pressure drop when an airflow is generated through the DPF, which allows for a reading on the appropriate values for a clean DPF, but the results of which can also be used to determine the DPF needs further cleaning. Again, a visual check can be performed as well.

[0066] Once the DPFs (1) are considered clean, the DPFs (1) are forwarded to a next station comprising a weighing unit (9).. The DPFs are weighed before the start of the cleaning process, and weighed again at this point at the weighing unit (9), which shows the weight of material (soot) removed from the DPF during cleaning, which data is the saved in the database.

[0067] Simultaneously, Selective Catalytic Reduction (SCR) units can be provided to a catalyst testing machine (6), which reuses the exhaust gases of the diesel generator (5) that powers the oven (2), in order to test the catalytic activity of the SCR unit. This is done by exposing the SCR unit to a gas stream simulating realistic circumstances, namely the exhaust gas of a diesel generator, which contains representative diesel exhaust components, including soot, hydrocarbons, carbon monoxide, and nitrogen oxides (NOx). By using the diesel generator (5) that is already present to power the oven (1), the 'test' gas stream accurately represents the normal use. During this process, urea solution (AdBlue or DEF) is typically introduced in the exhaust stream. In a next phase, the SCR is monitored and data is collected, for instance, exhaust gas temperature, NOx gas concentration at the inlet and outlet of the SCR, urea consumption rate and SCR catalyst temperature. Based on this data, the efficiency of the SCR unit can be evaluated.

[0068] 1 : DPF

[0069] 2: oven

[0070] 3: pneumatic device or PAGD

[0071] 4: vibration table

[0072] 5: diesel generator

[0073] 6: catalyst testing machine

[0074] 7: loading unit

[0075] 8: transport unit

[0076] 9: weighing unit

[0077] 10: laser engraving unit

[0078] It is supposed that the present invention is not restricted to any form of realization described previously and that some modifications can be added to the presented example of fabrication without reappraisal of the appended claims. For example, the present invention has been described referring to cleaning of DPFs of ships and vessels, but it is clear that the invention can be applied to any type of DPF, in every possible application.

[0079] The present invention is in no way limited to the embodiments described in the examples and / or shown in the figures. On the contrary, methods according to the present invention may be realized in many different ways without departing from the scope of the invention.

Claims

CLAIMS1. A system for maintenance of Diesel Particulate Filters (DPFs), comprising(a) an oven (2) suitable for receiving one or more DPFs (1), said oven being configured for the thermal regeneration of the received DPFs;(b) a pneumatic device (3) configured for cleaning filters of the thermally regenerated DPFs via pneumatic shock waves and / or a pressurized airflow generating device (PAGD) (3) configured for cleaning filters of the thermally regenerated DPFs via one or more pressurized air streams.(c) a power supply configured for generating power for the oven, characterized in that the pneumatic device and / or the PAGD is mounted on a vibration table (4) via a shock-absorbing connection, wherein said vibration table is suitable for receiving the thermally regenerated DPFs and is configured for vibrating the received DPFs.

2. The system according to claim 1, further comprising a catalyst testing machine (6) configured for testing catalyst performance of a Selective Catalytic Reduction (SCR) unit simultaneous with the thermal regeneration of the received DPFs with the oven.

3. The system according to claim 2, wherein the catalyst testing machine is suitable for simultaneously testing the catalyst performance of multiple SCR units.

4. The system according to any of the previous claims, wherein the power supply is a diesel generator (5), wherein the exhaust of the diesel generator is connected to the catalyst testing machine, whereby the catalyst testing machine is configured to use the exhaust gasses of the diesel generator for catalyst testing.

5. The system according to any of the previous claims, comprising one or more magnets integrated into the pneumatic device and / or the PAGD for collecting metal residues, preferably iron residues, from an exhaust of the pneumatic device and / or the PAGD.

6. The system according to any of the previous claims, further comprising a monitoring device for monitoring a backpressure in the pneumatic device.

7. The system according to any of the previous claims, wherein the system comprises pressurized an airflow generating device (PAGD) (3) configured for cleaning filters of the thermally regenerated DPFs via one or more pressurized air streams, said PAGD comprising one or more air knives.

8. A method for maintaining diesel particulate filters (DPF), comprising(a) thermally regenerating DPFs (1) using an oven (2);(b) cleaning said thermally regenerated DPFs with pneumatic shock waves via a pneumatic device (3) and / or with one or more pressurized air streams via a pressurized airflow generating device (PAGD) (3); characterized in that the method comprises a step of: vibrating the thermally regenerated DPF during the step of cleaning the thermally regenerated DPF with pneumatic shock waves and / or pressurized air streams, and in that said pneumatic device and / or PAGD is mounted on a vibration table (4) via a shock-absorbing connection, wherein said vibration table is suitable for receiving the thermally regenerated DPFs and wherein the method comprises a step of vibrating the received DPFs with the vibration table.

9. The method according to claim 8, further comprising a step of testing catalyst performance of a Selective Catalytic Reduction (SCR) unit using a catalyst testing machine (6).

10. The method according to claim 9, further comprising a step of testing multiple SCR units simultaneously.

11. The method according to claim 9 or 10, whereby said oven is powered by a diesel generator (5), and the catalyst performance of the SCR unit is tested with exhaust gas from the diesel generator.

12. The method according to any of the previous claims, comprising a step of collecting metal residues from the exhaust of the pneumatic device and / or PAGD, preferably by using one or more magnets.

13. The method according to claim 12, comprising a step of quantifying the collected metal residue and determining one or more diagnostic parameters for engine wear and tear, based on the quantified collected metal residue.

14. The method according to any of the claims 8 to 13, comprising a step of weighing the DPFs before and after maintenance to estimate the amount of soot removed; and of using the estimated amount of soot removed as an indicator for health diagnosis of a diesel engine for which the DPF was previously used as a filter.

15. The method according to any claim 8 to 14, further comprising a step of backpressure monitoring in the pneumatic device for DPF health and / or performance analysis.

16. The method according to any claim 8 to 15, wherein the step of cleaning said thermally regenerated DPFs is performed with one or more pressurized air streams via a pressurized airflow generating device (PAGD) (3), and wherein said PAGD comprises one or more air knives.

17. The method according to any of claims 8 to 16, further comprising the steps of:(a) recording cleaning data and catalyst testing data, said data comprising DPF weight, ambient temperature, DPF surface temperature and Selective Catalytic Reduction (SCR) catalyst efficiency;(b) storing said cleaning and catalyst testing data in one or more databases and(c) analyzing DPF health and / or performance based on at least said stored cleaning data.

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