WO2025038765A1 - Pulse air cleaner system with filter shield - Google Patents

Abstract

An air cleaner system including a housing, an inner filter, an outer filter, a sleeve, a shield, and a discharge outlet. The housing includes a dirty air inlet and a clean air outlet, and dirty air entering the housing through the dirty air inlet must pass through the outer filter, and then the inner filter, before entering the clean air outlet. The sleeve is positioned in an inter-filter volume between the inner filter and the outer filter. The shield is positioned in a sleeve-inner filter volume defined by the sleeve and the inner filter, the shield and the sleeve defining a sleeve-shield volume. The discharge outlet opens into the sleeve-shield volume, and pulsed gas entering the sleeve-shield volume moves along a filter axis. The shield includes shield openings to allow air to pass from the sleeve-shield volume to the inner filter.

Description

PULSE AIR CLEANER SYSTEM WITH FILTER SHIELD

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. 63/532,622, filed August 14, 2023, the disclosure of which is incorporated by reference herein in its entirety.

[0002] The disclosure herein relates generally to air cleaner assemblies and systems for use with, for example, vehicles and other equipment.

[0003] A variety of systems for pulse jet air cleaning are known. Examples described in U.S. Pat. Nos. 5,401,285; 5,575,826; 5,683,479; 6,676,721; 6,872,237; 6,908,494; and 9,108,135 as well as in US Patent Publication No. US 2022/0226764 are pulse jet air cleaners used in military and/or industrial vehicles. Such systems include an air filter in a housing with a pulse jet apparatus incorporated therein to periodically clean the filters using compressed gas such as, e.g., air. The air cleaning systems may include a sleeve inside of a filter located in a housing, the sleeve controlling flow of pulsed air/gas to protect the filter and/or improve pulse cleaning of the filter surrounding the sleeve.

SUMMARY

[0004] Air cleaner assemblies and systems for vehicles and related methods are described herein.

[0005] In one or more embodiments, the air cleaner assemblies and systems described herein include an inner filter located within the sleeve that is located within an outer filter in the housing of the air cleaner system. The inner filter may, in one or more embodiments, be referred to as a safety filter to prevent complete failure of the air cleaner system in the event the outer filter is compromised. Tn one or more alternative embodiments, the inner filter may also perform a different filtering function, e.g., filter finer particulate matter that passes through the outer filter (even if the outer filter is not compromised).

[0006] The air cleaner systems described herein may also include a filter shield located between the interior side of the outer filter and an exterior side of the inner filter.

[0007] Filter shields as described herein may be useful to protect the inner filters during pulse cleaning and/or disperse a cleaning pulse of gas (e.g., air) delivered to the interior of the sleeve to remove particulate matter collected on the exterior of the outer filter to restore the ability of the outer filter to clean dirty air delivered into the air cleaner system housing. In the absence of a filter shield, the cleaning pulse may damage an inner filter as the pulse travels between the sleeve and along the length of the exterior side of the inner filter.

[0008] In one or more embodiments, an illustrative air cleaner system as described herein may include a housing including a dirty air inlet and a clean air outlet. The air cleaner system may include an inner filter located in the housing, the inner filter sealed about the clean air outlet such that dirty air entering the housing through the dirty air inlet must pass through the inner filter before entering the clean air outlet. The air cleaner system may include an outer filter located in the housing, the outer filter including a first end sealed inside the housing proximate the clean air outlet and a second end located distal from the first end along a filter axis extending through the first end, the second end, and the clean air outlet. Dirty air entering the housing through the dirty air inlet must pass through the outer filter before passing through the inner filter. The air cleaner system may include a shield positioned in an inter-filter volume between the inner filter and the outer filter, the shield at least partially surrounding the inner filter along the circumference of the inner filter, and the shield and the outer filter defining a shield-outer filter volume within the inter-filter volume. The air cleaner system may include a discharge outlet opening into the shield-outer filter volume, wherein pulsed gas entering the shield-outer fdter volume through the discharge outlet moves along the filter axis through the shield-outer filter volume.

[0009] In one or more embodiments, an illustrative air cleaner system as described herein may include a housing including a dirty air inlet and a clean air outlet. The air cleaner system may further include an inner filter located in the housing, the inner filter sealed about the clean air outlet such that dirty air entering the housing through the dirty air inlet must pass through the inner filter before entering the clean air outlet. The air cleaner system may further include an outer filter located in the housing, the outer filter including a first end sealed inside the housing proximate the clean air outlet and a second end located distal from the first end along a filter axis extending through the first end, the second end, and the clean air outlet. Dirty air entering the housing through the dirty air inlet may pass through the outer filter before passing through the inner filter. The inner filter and the outer filter may define an inter-filter volume therebetween. The air cleaner system may further include a discharge outlet opening into the inter-filter volume. Pulsed gas entering the inter-filter volume through the discharge outlet may move along the filter axis through the inter-filter volume.

[0010] In one or more embodiment, a filter element includes a filter media having a first end and a second end. The filter element further includes a first, open end cap coupled to the first end of the filter media. The filter element further includes a second end cap coupled to the second end of the filter media. The filter element further includes a baffle coupled to the first open end cap, the baffle having a portion projecting radially outward from the filter media at an angle greater than zero.

[0011] The above summary is not intended to describe each embodiment or every implementation of the present disclosure. A more complete understanding will become apparent and appreciated by referring to the following detailed description and claims taken in conjunction with the accompanying drawings. In other words, these and various other features and advantages will be apparent from a reading of the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The disclosure may be more completely understood in consideration of the following detailed description of various embodiments of the disclosure in connection with the accompanying drawings.

[0013] FIG. 1 is a perspective view of one illustrative embodiment of a vehicle incorporating an air cleaner system as described herein;

[0014] FIG. 2 is an exploded view of one illustrative embodiment of an air cleaner system as described herein;

[0015] FIG. 3 is a cross-sectional exploded view of the air cleaner system of FIG. 2;

[0016] FIG. 4 is a perspective cross-sectional view of the air cleaner system of FIG. 2;

[0017] FIG. 5 is a cross-sectional view of the air cleaner system of FIG. 4;

[0018] FIG. 6 is a perspective view of an inner filter and filter shield of the air cleaner system of FIG. 2;

[0019] FIG. 7 is a schematic of airflow through one or more of the inner filter and the filter shield of the air cleaner system of FIG. 2;

[0020] FIG. 8 is a perspective cross-sectional view of an air cleaner system;

[0021] FIG. 9 is a cross-sectional view of the air cleaner system of FIG. 8;

[0022] FIG. 10 is a perspective view of a duct of the air cleaner system of FIG. 8;

[0023] FIG. 11 is a partial perspective cross-sectional view of the air cleaner system of FIG. 8;

[0024] FIG. 12 is another partial perspective cross-sectional view of the air cleaner system of FIG. 8;

[0025] FIG. 13 is a perspective cross-sectional view of an air cleaner system;

[0026] FIG. 14 is a cross-sectional view of the air cleaner system of FIG. 13;

[0027] FIG. 15 is an axial cross-sectional view of the air cleaner system of FIG. 13; [0028] FIG. 16 is a perspective cross-sectional view of an air cleaner system;

[0029] FIG. 17 is a cross-sectional view of the air cleaner system of FIG. 16;

[0030] FIG. 18 is a perspective cross-sectional view of an air cleaner system;

[0031] FIG. 19 is a cross-sectional view of the air cleaner system of FIG. 18;

[0032] FIG. 20 is a schematic partial cross-sectional view of the air cleaner system of FIG. 18;

[0033] FIG. 21 is another schematic partial cross-sectional view of the air cleaner system of FIG. 18;

[0034] FIG. 22 is a schematic cross-sectional view of an air cleaner system;

[0035] FIG. 23 is a perspective cross-sectional view of the air cleaner system of FIG. 22;

[0036] FIG. 24 is a cross-sectional view of the air cleaner system of FIG. 22; and

[0037] FIG. 25 is another schematic cross-sectional view of the air cleaner system of FIG. 22.

DETAILED DESCRIPTION

[0038] The disclosure herein includes illustrative embodiments of systems, apparatus, structures, and methods for an air cleaner system including a filter shield.

[0039] In one or more embodiments, the air cleaner systems described herein may be used with a pulse cleaning apparatus (e.g., a pulse jet cleaner) that may be configured to deliver air/gas to the air cleaner systems described herein to move debris and sediment off of filter media (e.g., an exterior surface of an outer filter media) within the housing. For example, the pulse cleaning apparatus may, in one or more embodiments, conduct a pulse cleaning operation that may selectively clean a dirty filter without manual user interaction (e.g., without the user physically cleaning the filter). The pulse cleaning operation may be configured for manual or automatic activation (e.g., an operator may actuate or start the cleaning operation through wired or wireless electronics; or the cleaning operation may begin automatically based on a state or cleanliness of the filter).

[0040] Further, the filter shield may work in conjunction with the pulse cleaning apparatus. For example, in one or more embodiments, the filter shield may be positioned within the housing such that gas or air from the pulse cleaning apparatus is dispersed within a sleeve-inner filter volume to prevent or limit damage to the inner filter. In other words, the filter shield may, in one or more embodiments, be sized to correspond with the pulse cleaning apparatus to improve pulse cleaning of the outer filter as described herein while also protecting the inner filter. Pulse cleaning may be improved by, e.g., achieving flow of air pulsed from the pulse cleaning apparatus within the sleeve at ideal pressures.

[0041] One illustrative embodiment of an air cleaner system within a vehicle 10 is depicted in FIG. 1. Specifically, FIG. 1 illustrates a tank, however, the air cleaner system described herein may be applied to air cleaner systems of a variety of vehicles and/or equipment. For example, the air cleaner system may be implemented within cars, tractors, on-road trucks, armored vehicles, tracked personnel carriers, wheeled vehicles, mobile generators, stationary generators, etc.

[0042] The illustrative vehicle 10 may include an inlet 12 configured to allow the flow of air from the exterior environment, through filter media, and towards the engine intake. The inlet 12 may be located at any suitable location on the vehicle 10. Further, the vehicle 10 may include an outlet 14 configured as a passageway for detached particulate matter (e.g., debris, dust, sediment, etc.) to exit the air cleaner system after being pulsed from the outer filter. The outlet 14 may be located at any suitable location on the vehicle 10. For example, the outlet 14 may disperse particulate matter into a general exhaust of the vehicle 10.

[0043] The air cleaner system as described herein may provide for hands-off solutions to maintaining a clean filter system. For example, the pulse cleaner apparatus may help to further automate the cleaning process to ensure an efficient and effective way to maintain a clean filter. [0044] In one or more embodiments, the air cleaner system 100 described herein may be similar to the air cleaner systems described in, e.g., U.S. Pat. No. 8,404,021 entitled “Air Cleaner Having Scavenger Arrangement,” U.S. Pat. No. 5,683,479 entitled “Pulse Jet Air Cleaner System; Components; and, Methods,” U.S. Pat. No. 7,927,396 entitled “Evacuation Value Arrangements; Pulse Jet Air Cleaner Systems Using Same; and, Method,” and U.S. Pat. No. 9,186,612 entitled “Pulse Jet Air Cleaner Systems; Evacuation Valve Arrangements; Air Cleaner Components; and Methods.”

[0045] Air Cleaner System and Inner and Outer Filters

[0046] FIG. 2 illustrates an exploded view of one illustrative embodiment of the air cleaner system 100 including a housing 102 (102-1 and 102-2). FIG. 3 illustrates a cross-sectional exploded view of the same (the cross-section taken in a plane containing the filter axis 101). The air cleaning housing 102 may include a dirty air inlet 104 and a clean air outlet 118. The dirty air inlet 104 may extend from the inlet 12 of the vehicle 10 (e g., as shown in FIG. 1). The clean air outlet 118 may be in fluid communication with the engine intake such that filtered air passes from the clean air outlet 118 to the engine intake. The housing 102 may include a first housing section 102-1 and a second housing section 102-2 coupled to the first housing section 102-1. The first housing section 102-1 may be positioned between the dirty air inlet 104 and the clean air outlet 118 and configured to receive an inner filter 110 and an outer filter 112. In one or more embodiments, the inner filter 110 is located in the housing 102. In one or more embodiments, the outer filter 112 is located in the housing 102.

[0047] The air cleaner system 100 may extend between a first housing end 120 located proximate the clean air outlet 118 and a second housing end 122 distal to the first housing end 120 along a filter axis 101. The air cleaner system 100 may also include a housing end cap 114 proximate the second housing end 122. In some embodiments, the housing end cap 114 may be removably couplable to the first housing section 102-1 such that the inner filter 110 and the outer filter 112 may be inserted into and removed from the housing 102 through an opening created by removing the housing end cap 114. For example, and as shown in FIG. 2, the housing end cap 114 may include one or more locks 114a. The one or more locks 114a may seal the housing end cap 114 to the housing 102, such that there is no airflow through the housing end cap 114. In alternative embodiments, the housing 102 may include an access panel (not shown) configured to allow for insertion and removal of the inner filter 110 and the outer filter 112. The access panel may be located anywhere on the housing 102 (see, e.g., US Patent Publication No. US 2022/0226764).

[0048] In one or more embodiments, the housing end cap 114 may have an internal cone shape 115 (FIG. 3) that widens away from the interior of the housing 102. Such a cone shape 115 may advantageously push gas pulses towards the outer filter 112, and may further add robustness and strength to the housing end cap 114 and provide alignment with at least one of the inner and outer filters 110, 112. In one or more embodiments, the housing end cap 114 is sufficiently stiff to avoid drumming of the housing end cap 114 or the housing 102, which may advantageously avoid or prevent damage to the cleaner system 100.

[0049] Further, the housing 102 may define a housing length 124 between the first housing end 120 and the second housing end 122 measured along the filter axis 101, as shown in FIG. 4. In one or more embodiments, the housing length 124 is longer than an inner filter length 128 and an outer filter length 126, as shown in FIG. 4. Thus, once the air cleaner system 100 is fully assembled, the inner and outer filters 110, 112 are fully enclosed within the housing 102 and the housing end cap 114.

[0050] Furthermore, as shown in FIGS. 2-5, the air cleaner system 100 may include the inner filter 110 and the outer filter 112 located within the housing 102. The inner and outer filters 110, 112 may extend along the filter axis 101. The inner filter 110 may extend along the filter axis 101 from an inner filter first end 130 to an inner filter second end 132 (FIG. 3). The outer filter 112 may extend along the filter axis 101 from an outer filter first end 134 to an outer filter second end 136 (FIG. 3). The housing end cap 1 14 may be proximate the second end 136 of the outer filter 112.

[0051] Further, the inner and outer filters 110, 112 may include filter media configured to filter air passing through the filter media. For example, air entering the housing 102 through the dirty air inlet 104 may pass through the filter media of both the inner and outer filters 110, 112 before passing out of the housing 102 through the clean air outlet 118 (and on to the engine intake). In other words, the filter media may be positioned such that air passing between the dirty air inlet 104 and the clean air outlet 118 must travel through the filter media of the outer filter 112 and then through the filter media of the inner filter 110.

[0052] In one or more embodiments, the inner filter 110 may be sealed about the clean air outlet 118 such that dirty air entering the housing 102 through the dirty air inlet 104 must pass through the inner filter 110 before entering the clean air outlet 118. In one or more embodiments, the outer filter 112 may include the outer filter first end 134 sealed inside the housing 102 proximate the clean air outlet 118, and an outer filter second end 136 located distal from the outer filter first end 134 along the filter axis 101. The filter axis 101 may extend through the outer filter first end 134, the outer filter second end 136, and the clean air outlet 118. In one or more embodiments, dirty air entering the housing 102 through the dirty air inlet 104 must pass through the outer filter 112 before passing through the inner filter 110.

[0053] In one or more embodiments, the inner filter 110 includes a cylindrical filter extending along the filter axis 101 from the inner filter first end 130 to the inner filter second end 132. Optionally, the inner filter 110 may be in the form of a circular cylindrical inner filter. Optionally, and as shown in FIGS. 16 and 17, the inner filter 110 may be in the form of a conical cylindrical inner filter, with a larger diameter towards the clean air outlet 118 and a smaller diameter towards the housing end cap 114. Optionally, and as shown in FIGS. 22-25, the inner filter 110 may be in the form of a conical cylindrical inner filter, with a larger diameter towards the housing end cap 114 and a smaller diameter towards the clean air outlet 118. In one or more embodiments, the outer filter 112 may be in the form of a cylindrical filter extending along the filter axis 101 from the outer filter first end 134 to the outer filter second end 136. Optionally, the outer filter 112 may be in the form of a circular cylindrical outer filter.

[0054] In one or more embodiments, the inner filter 110 may define an inner filter opening 138 and an inner filter passage 139 extending within the inner filter 110 from the inner filter opening 138. In one or more embodiments, the outer filter 112 may define an outer filter opening 140 and an outer filter passage 141 extending within the outer filter 112 from the outer filter opening 140. The inner and outer filter openings 138, 140 may be located at either or both ends of each of the inner and outer filters 110, 112, respectively. For example, as shown in FIGS. 2-3, the inner filter opening 138 is located at the inner filter first end 130 and the outer filter opening 140 is located at the outer filter first end 134. Further, in one or more embodiments, the end of each of the inner and outer filters 110, 112 located opposite the filter opening may be closed or sealed. The filter passages 139, 141 may be defined by an inner filter surface of each of the inner and outer filters 110, 112.

[0055] The outer filter passage 141 may define a first-filtered clean air space, or inter- filter volume 160, within the housing 102 and, e.g., in fluid communication with the inner filter 110 (FIG. 4). The inter-filter volume 160 may be described as within the filter media of the outer filter 112, but not within the filter media of the inner filter 110 and, therefore, may only contain air that has been filtered once (e.g., due to air traveling from the dirty air inlet 104 and through the filter media of the outer filter 112).

[0056] Further, and as illustrated in FIGS. 2-5, the inner filter 110 may be located within the outer filter 112. The inner filter passage 139 may define a second-filtered clean air space within the housing 102 and, e.g., in fluid communication with the clean air outlet 118. The second-filtered clean air space may be described as within the filter media of the inner filter 110 and, therefore, may only contain air that has been twice filtered (e.g., due to air traveling from the dirty air inlet 104 and through the filter media of the outer filter 112 and through the filter media of the inner filter 110). As such, only twice-filtered air may proceed through the clean air outlet 118 and towards the engine intake.

[0057] In one or more embodiments, the inner and outer filters 110, 112 may include the same filter media. In alternative embodiments, the outer filter 112 may include filter media with a larger pore size, and the inner filter 110 may include filter media with a smaller pore size relative to the outer filter 112. Different pore sizes may advantageously allow for the outer filter 112 to provide a majority of the filtering of the air passing through the air cleaner system 100 and may allow for the inner filter 110 to provide further filtering of smaller particles that may have passed through the outer filter 112. Thus, the inner filter 110 may provide a safety check to ensure that air passing through the air cleaner system 100 is filtered to an ideal air quality, or to filter specific particles from the air, etc.

[0058] The inner and outer filters 110, 112 may be any suitable shape and size that forms a filter barrier between the dirty air inlet 104 and the clean air outlet 118. As shown in FIGS. 2-3, the inner and outer filters 110, 112 are cylindrical and have a circular/annular cross-section. The inner and outer filters 110, 112 used in one or more alternative embodiments of an air cleaner system described herein may define cross-sectional shapes (in, e.g., a plane perpendicular to the filter axis 101) including, e g., ovular, square, rectangular, hexagonal, octagonal, etc. Further, “annular” may mean any cylindrical shape (e.g., a cylinder formed by any closed geometric shape, including circular, octagonal, hexagonal, etc.).

[0059] Further, the outer filter 112 may, in one or more embodiments, be positioned away from the housing 102 such that a gap is provided between the outer filter 112 and the housing 102. This gap between the outer filter 112 and the housing 102 may provide a passageway for air to travel from the dirty air inlet 104 and disperse over the surface area of the filter media of the outer filter. In one or more embodiments, the gap may also improve access to the outer filter, improve filter loading capacity, improve volumetric flow through the air cleaner system, reduce pressure drop, etc. [0060] Still further, the inner filter 110 may, in one or more embodiments, be positioned away from the outer filter 112 such that a gap is provided between the outer filter 112 and the inner filter 110. This gap between the outer filter 112 and the inner filter 110 may provide a passageway for air to travel from the outer filter 112 and disperse over the surface area of the filter media of the inner filter. In one or more embodiments, the gap may also improve access to the inner filter, improve filter loading capacity, improve volumetric flow through the air cleaner system, reduce pressure drop, etc.

[0061] In one or more embodiments, both of the inner and outer filters 110, 112 may be configured to be positioned within housing 102 such that both of the inner and outer filters 110, 112 may axially seal with the housing 102 (e g., relative to the filter axis 101). For example, the outer filter 112 may interface and seal with the housing 102 at the first and second outer filter ends 134, 136, and the inner filter 110 may interface and seal with the housing 102 at the inner filter first end 130. In one or more embodiments, the inner filter 110 may be coupled to the housing 102 and the outer filter 112 may be coupled to the inner filter 110.

[0062] The air cleaner system 100 may, in one or more embodiments, also include at least one of a pulse cleaning apparatus 103-1 and a pulse cleaning apparatus 103-2. Each of the pulse cleaning apparatus 103-1 and 103-2 may be configured to produce a pulse of air (or any suitable gas or gasses) within the inter-filter volume 160 to provide a cleaning force on the outer filter media from within the interfilter volume 160.

[0063] The pulse cleaning apparatus 103-1 and 103-2 used in the air cleaner systems described herein may take any suitable form capable of delivering pulses of gas/air into the system to clean the outer filter as described herein.

[0064] For example, in the depicted illustrative embodiment the pulse cleaning apparatus 103-1 and 103-2 includes a pulse tube 182 within the housing 102.

[0065] The depicted illustrative embodiment of the air cleaner system includes a discharge outlet 184 in fluid communication with the pulse tube 182, the discharge outlet 184 opening into the inter-fdter volume 160 and facing away from the clean air outlet 1 18 (FIG. 4). In one or more embodiments, pulsed gas entering the inter-fdter volume 160 through the discharge outlet 184 may move along the filter axis 101 through the inter-filter volume 160. As a result, the force from the pulse of air of the pulse cleaning apparatus 103-1 and 103-2 travels from the discharge outlet 184 to the outer filter 112 to detach or separate particulate (e.g., that has accumulated on the exterior of the outer filter 112) from the exterior surface of the outer filter 112. The pulse cleaning apparatus 103-1 and 103-2 may include any suitable number of pulse jet cleaners (e.g., one, two, three, four, etc.). Further, in one or more embodiments, the pulse cleaning apparatus 103-1 and 103- 2 may be similar to the pulse assembly described in, e.g., U.S. Pat. No. 8,404,021 entitled “Pulse jet Air Cleaner System; Components; and, Methods.”

[0066] The second housing section 102-2 may further optionally include an additional pulse cleaning apparatus (not shown) to pulse air from the clean air outlet 118 and into the inner passage 139 of the inner filter 110. As a result, the force from the pulse of air of such a pulse cleaning apparatus travels from the discharge outlet 184 to the inner filter 110 to detach or separate particulate (e.g., that has accumulated on the exterior of the inner filter 110) from the exterior surface of the inner filter 110.

[0067] The discharge outlet 184 may be partially defined by a duct 180 (FIGS. 3-5). The duct 180 may operatively couple the inner filter 110 to the housing 102. Such operative coupling may advantageously ensure proper installation and placement of the inner filter 110 relative to the rest of the system 100. In alternative embodiments, the duct 180 may be integral with the second housing section 102- 2, which may advantageously reduce system complexity. The duct 180 may be constructed out of one or more of metal (e.g., steel, aluminum, etc.), alloy, plastic, ceramic, composite material, etc.

[0068] The duct 180 may operatively couple the inner filter 110 to the housing 102. Such operative coupling may advantageously ensure proper installation and placement of the inner filter 110 relative to the rest of the system 100. The duct 180 may be shaped to define the discharge outlet 184 to optimize cleaning effectivity and efficiency of the system 100. For example, a circular annulus may be formed, an elliptical annulus may be formed, a segmented/partial annulus may be formed, or other shaped annuluses may be formed. The duct 180 may be shaped to increase the speed of the air moving from the pulse cleaning apparatus and into the interfilter volume 160. Increasing the air speed may advantageously improve cleaning of the outer filter 112.

[0069] Although the depicted embodiment of the discharge outlet 184 is in the form of a continuous annular ring, one or more alternative embodiments of the air cleaner systems described herein may include one or more discharge outlets opening into the inter-filter volume and configured to deliver cleaning pulses as described herein. For example, as discussed further herein, the duct 180 may define a segmented annulus such that each discharge outlet is separated from any other discharge outlets.

[0070] As shown in FIG. 4, the discharge outlet 184 of the pulse cleaning apparatus 103- 1 and 103-2 may be positioned proximate the inner filter first end 130. Further, it may be described that the pulse cleaning apparatus 103-1 and 103-2 (e.g., the pulse tube 182 and the discharge outlet 184 for each of apparatus 103-1 and 103- 2) may be positioned beyond the inner filter first end 130. In other words, the pulse cleaning apparatus 103-1 and 103-2 may not be located within the inner filter passage 139. Therefore, the inner and outer filters 110, 112 may be inserted into or removed from the housing 102 without contacting or interacting with any portion of the pulse cleaning apparatus 103-1 and 103-2. In other words, the pulse cleaning apparatus 103-1 and 103-2 may not interfere with installation or removal of the inner and outer filters 110, 112. Further, the discharge outlet 184 may include an annular discharge outlet 184.

[0071] As shown using the numbered arrows in FIG. 5, the pulse cleaning apparatus 103- 1 and 103-2 create a pulse of gas (e.g., air) which travels from arrow 1 to arrow 2 (e g., from the pulse tube 182 to the discharge outlet 184). Then, the pulse of gas travels out of the discharge outlet 184 throughout the inter-filter volume 160 along arrows 3 and 4 (discussed further herein) before moving through the outer filter 112 (i.e., from an interior of the outer filter 112 to an exterior of the outer filter

112) and removing debris from the exterior of the outer filter 112.

[0072] Inner Sleeve

[0073] The air cleaner system 100 further includes an inner sleeve 106 and a shield 108 (FIGS. 2-5). The inner sleeve 106 and the shield 108 may be positioned within the inter-filter volume 160 and between the inner and outer filters 110, 112.

[0074] In one or more embodiments, the inner sleeve 106 may extend along the filter axis

101 away from the clean air outlet 118 towards the outer filter second end 136. In one or more embodiments, optionally, the inner sleeve 106 may be sealed about the clean air outlet 118 proximate the outer filter first end 134. The inner sleeve 106 may extend along the filter axis 101 such that the inner sleeve 106 extends from a sleeve first end 142 to a sleeve second end 144 (FIG. 5). The sleeve first end 142 may be proximate the clean air outlet 118. The sleeve first end 142 may be coupled to the housing 102 proximate the first end 130 of inner filter 110. The sleeve first end 142 may be coupled to the housing 102 proximate the first end 134 of outer filter 112. The sleeve first end 142 may be coupled to the housing

102 proximate the discharge outlet 184. The sleeve first end 142 may be coupled to the inner filter 110 proximate the inner filter first end 130 (see A of FIG. 5 schematically demonstrating where at least a portion of the sleeve first end 142 may be operatively coupled to the inner filter 110 proximate the inner filter first end 130). The sleeve second end 144 may be located anywhere between the first ends 130, 134 of the inner and outer filters 110, 112, respectively, and the housing end cap 114 such that the inner sleeve 106 defines a sleeve length 146. The sleeve length 146 may be less than half of the outer filter length 126, half of the outer filter length 126, or more than half of the outer filter length 126. The sleeve length 146 may be less than half of the inner filter length 128, half of the inner filter length 128, or more than half of the inner filter length 128. The sleeve length 146 may be less than half of the housing length 124, half of the housing length 124, or more than half of the housing length 124. [0075] In one or more embodiments, the sleeve second end 144 may be located between the first end and the second ends 134, 136 of the outer filter 112. Optionally, the sleeve second end 144 may be located closer to the second end 136 of the outer filter 112 than the first end 134 of the outer filter 112.

[0076] In one or more embodiments, the inner sleeve 106 has a length sufficient to prevent or limit creation of a vacuum on the interior surface of the outer filter 112 during pulse delivery. Without the inner sleeve 106, the pulsed gas exiting the discharge outlet 184 may create a vacuum or pressure drop on the interior surface of the outer filter 112 that could damage the outer filter 112. The inner sleeve 106 may advantageously prevent or limit such damage by guiding the pulsed gas along the sleeve length 146 before allowing the pulsed gas to impinge upon the housing end cap 114 and the outer filter 112 (FIG. 5, arrows 3-5).

[0077] Further, the inner sleeve 106 may be configured to allow gas entering the interfilter volume 160 from the discharge outlet 184 to disperse evenly before exiting the inner sleeve 106 (e.g., to form a laminar pulse flow). In other words, the inner sleeve 106 may be dimensioned (e.g., have a length and/or size) such that gas exiting the discharge outlet 184 expands to the diameter of the inner sleeve 106 by the time the gas reaches the sleeve second end 144. Therefore, cleaning pulses may be uniformly dispersed such that the gas may be more effectively delivered to the interior surface of the filter media of the outer filter 112 to remove sediment or debris from the exterior surface of the outer filter 112.

[0078] In one or more embodiments, the inner sleeve 106 may be fixedly coupled or integral with the inner filter 110 and/or the outer filter 112. This may advantageously ensure that the inner sleeve 106 is present as the inner filter 110 and/or outer filter 112 is installed, proper sizing of the various parts is ensured, proper placement of the various parts is ensured, maintaining the position of the various parts after installation of the filters 110, 112 in the housing 102 is ensured, etc. In alternative embodiments, the inner sleeve 106 may be removably couplable to the inner filter 110 and/or outer filter 112. This may advantageously allow for the same inner sleeve 106 to be re-used with new or replacement inner filters 110 and/or outer filters 112.

[0079] Additionally, the inner sleeve 106 may extend along (e.g., be concentric to) the inner filter 110 for the sleeve length 146, measured along the filter axis 101. For example, a majority of the inner sleeve 106 may be shaped such that the inner sleeve 106 is coextensive with the inner filter 110. Specifically, at least a portion of the inner sleeve 106 may be spaced a gap distance away from the inner filter 110 such that the inner sleeve 106 and the inner filter 110 define a sleeve-inner filter volume 162 (FIG. 4) within the inter-filter volume 160. The sleeve-inner filter volume 162 may allow for the access of gas dispersed therethrough (e.g., air being filtered through the filter media, pulses of gas from, e.g., the pulse cleaning apparatus, etc.).

[0080] The inner sleeve 106 may be constructed of any suitable material or materials. For example, the inner sleeve 106 may include (e.g., be formed of) one or more materials such as, e.g., steel, aluminum, plastic, etc. Further, the inner sleeve 106 may be impermeable to gas/air (e.g., include no openings in the inner sleeve 106). In other embodiments, the inner sleeve 106 may include one or more sleeve openings 172 (e.g., illustrated in FIG. 7) through which fluid may pass. The sleeve openings 172 may advantageously improve the system performance (e g., by reducing pressure drop within the inter-filter volume 160, etc.). The sleeve openings 172 may be spaced apart along the filter axis 101. The sleeve openings 172 may be configured to allow air entering the inter-filter volume 160 through the outer filter 112 to pass through the inner sleeve 106 into a sleeve-shield volume 164 (FIG. 4, discussed further herein). The sleeve openings 172 may have any suitable shape, dimensions, and quantity (e.g., they may be uniform or non- uniform, patterned or non-pattemed, etc.).

[0081] In one or more embodiments, the size and/or spacing of the one or more sleeve openings 174 changes when moving away from the discharge outlet 184 along the filter axis 101 (FIG. 7). This may advantageously control the pulsed gas to more efficiently and/or more effectively clean the outer filter 112 and the air cleaner system 100 as a whole. For example, as illustrated in FIG. 7, the sleeve openings 174 become larger in a direction parallel to the filter axis 101 in a direction along the filter axis 101 away from the discharge outlet 184. Larger openings may advantageously allow for more air to filter through the inner filter 110 but may also create a vacuum against the inner filter 110 created by the pulsed gas. Thus, larger openings may be more advantageous farther away from the discharge outlet 184, because there is less risk of creating a vacuum, and this allows for more efficient filtering of air through the system.

[0082] In one or more embodiments, the inner sleeve 106 may be configured to control passage of gas (e.g., from the pulse cleaning apparatus 103-1 and 103-2) such that a majority of gas entering the sleeve-inner filter volume 162 exits the sleeve-inner filter volume 162 through the sleeve second end 144.

[0083] The sleeve second end 144 may be coupled to the housing end cap 114 (see B of FIG. 5 schematically demonstrating where the inner sleeve 106 may be coupled to the housing end cap 114). As a result, the inner sleeve 106 may be axially located (e.g., along the filter axis 101) relative to the inner filter 110. Optionally, one or both of the inner sleeve 106 and the shield 108 may be attached to the housing end cap 114.

[0084] Shield

[0085] The shield 108 may be considered a “filter shield” 108. In one or more embodiments, the shield 108 may extend along the filter axis 101 away from the clean air outlet 118 towards the outer filter second end 136. In one or more embodiments, the shield 108 may be positioned in the sleeve-inner filter volume 162 between the inner sleeve 106 and the (exterior surface of) inner filter 110. In one or more embodiments, the shield 108 and the inner sleeve 106 may define the sleeve-shield volume 164 between the inner sleeve 106 and the shield 108. The filter shield 108 may extend along the filter axis 101 such that the filter shield 108 extends from a shield first end 150 to a shield second end 152 (FIG. 5). [0086] The shield first end 150 may be proximate the clean air outlet 118, and further may be coupled to the housing 102 proximate the clean air outlet 118 such that the shield remains attached to the housing after removal of the inner filter. The shield first end 150 may be coupled to the housing 102 proximate the first end 130 of inner filter 110. The shield first end 150 may be coupled to the housing 102 proximate the first end 134 of outer filter 112. The shield first end 150 may be coupled to the housing 102 proximate the discharge outlet 184. The shield first end 150 may be coupled to the inner filter 110 proximate the inner filter first end 130 (see portion of A of FIG. 5 schematically demonstrating where the shield first end 150 may be operatively coupled to the inner filter 110 proximate the inner filter first end 130) such that the shield 108 is removed from the housing 102 with removal of the inner filter 110 from the housing 102.

[0087] The shield second end 152 may be located anywhere between the first ends 130, 134 of the inner and outer filters 110, 112, respectively, and the housing end cap 114 such that the shield 108 defines a shield length 154. The shield length 154 may be less than half of the outer filter length 126, half of the outer filter length 126, or more than half of the outer filter length 126. The shield length 154 may be less than half of the inner filter length 128, half of the inner filter length 128, or more than half of the inner filter length 128. The shield length 154 may be less than half of the housing length 124, half of the housing length 124, or more than half of the housing length 124.

[0088] The shield 108 may at least partially surround or fully surround the inner filter 110 along a circumference of the inner filter 110. For example, when the shield 108 fully surrounds the inner filter 110 along the circumference of the inner filter 110, the inner filter 110 may be protected from particulate matter, and the pulsed gas may be directed towards the outer filter 112 along the entire circumference of the filters. Conversely, for example, when the shield 108 partially surrounds the inner filter 110 along the circumference of the inner filter 110, the shield 108 may be designed to direct pulsed gas towards area(s) of the outer filter 112 proximate the dirty air inlet 104 and/or experiencing more particulate matter to maximize cleaning efficiency and effectivity while minimizing cost. Further, when the shield 108 partially surrounds the inner filter 110 along the circumference of the inner filter 110, the system 100 may allow for faster airflow filtration over time.

[0089] In one or more embodiments, the shield 108 may extend along the filter axis 101 away from the shield first 150 end proximate the clean air outlet 118 to the shield second end 152, and the shield second end 152 may be located between the first end and the second end 134, 136 of the outer filter 112. Optionally, the shield second end 152 is located closer to the second end 136 of the outer filter 112 than the first end 134 of the outer filter 112.

[0090] In one or more embodiments, the shield length 154 may be selected to prevent or limit creation of a vacuum or pressure drop on the exterior surface of the inner filter 110 that is sufficient to damage the inner filter 110. Without the shield 108, the pulsed gas exiting the discharge outlet 184 may create a vacuum or pressure drop on the exterior surface of the inner filter 110 that is sufficient to damage the inner filter 110. The shield 108 may advantageously prevent or limit such damage by guiding the pulsed gas away from the exterior surface of the inner filter 110 and/or by preventing the pulsed gas from directly impinging on the inner filter 110.

[0091] In one or more embodiments, the shield length 154 is greater than the sleeve length 146 (FIG. 5). The inner sleeve 106 may extend along the filter axis 101 away from the sleeve first end 142 to the sleeve second end 144, and the shield may extend along the filter axis 101 away from the shield first end 150 to the shield second end 152, and the shield second end 152 may be located between the sleeve second end 144 and the second end 136 of the outer filter 112. This may advantageously guide the pulsed gas along the entire sleeve length 146 to protect the inner filter 110 from the pulsed gas before the pulsed gas exits the inner sleeve 106 and disperses throughout the inter-filter volume 160.

[0092] Further, the filter shield 108 may be configured to promote even dispersion of gas entering the inter-filter volume 160 through the discharge outlet 184 before exiting the inner sleeve 106 (e g., to form a laminar pulse flow). In other words, the filter shield 108 may be dimensioned (e.g., have a length and/or size) such that gas exiting the discharge outlet 184 expands to the diameter of the inner sleeve 106 by the time the gas reaches the sleeve second end 144. Therefore, the gas from discharge outlet 184 may be uniformly dispersed such that the gas may be more effectively delivered to pulse the filter media of the outer filter 112 to remove sediment or debris from the exterior surface of the outer filter 112.

[0093] In one or more embodiments, the filter shield 108 may be fixedly coupled or integral with the inner filter 110 and/or the outer filter 112. This may advantageously ensure that the filter shield 108 is present as the inner filter 110 and/or outer filter 112 is installed, proper sizing of the various parts is ensured, proper placement of the various parts is ensured, maintaining the position of the various parts after installation of the filters 110, 112 in the housing 102 is ensured, etc. In alternative embodiments, the filter shield 108 may be removably couplable to the inner filter 110 and/or outer filter 112. This may advantageously allow for the same filter shield 108 to be re-used with new or replacement inner filters 110 and/or outer filters 112.

[0094] Additionally, the filter shield 108 may extend along (e.g., be concentric to) the inner filter 110 for the shield length 154, measured along the filter axis 101. For example, a majority of the filter shield 108 may be shaped such that the filter shield 108 is coextensive with the inner filter 110. Specifically, at least a portion of the filter shield 108 may be spaced a gap distance away from the inner sleeve 106 such that the filter shield 108 and the inner sleeve 106 define a sleeve-shield volume 164 between the inner sleeve 106 and the filter shield 108 and within the sleeve-inner filter volume 162. The sleeve-shield volume 164 may allow for the access of gas dispersed therethrough (e.g., air being filtered through the filter media, pulses of gas from the discharge outlet 184 towards the outer filter 112, etc.).

[0095] In one or more embodiments, one or more of the inter-filter volume 160, sleeve- inner filter volume 162, and sleeve-shield volume 164 includes a cylindrical volume (e.g., a circular cylindrical volume, an elliptical cylindrical volume, etc.), a conical volume, an annular volume, etc., or any combination thereof. [0096] The filter shield 108 may be constructed of any suitable material or materials. For example, the filter shield 108 may include (e.g., be formed of) one or more materials such as, e.g., steel, aluminum, plastic, etc. Further, the filter shield 108 may be impermeable to gas/air (e.g., the filter shield 108 may include no openings).

[0097] In one or more embodiments such as the depicted illustrative embodiment, the filter shield 108 includes one or more louvers 170 (FIG. 6) and one or more shield openings 174 between the louvers 170 spaced apart along the filter axis 101. The one or more shield openings 174 may be configured to allow air to pass from the sleeve-shield volume 164 to the exterior surface of the inner filter 1 10 (FIG. 6). The one or more shield openings 174 may be located between the one or more louvers 170 when moving along the filter axis 101. The one or more shield openings 174 may face away from the discharge outlet 184 (to, e.g., promote the passage of pulsed gas passing along the outer surface of the shield 108). The shield openings 1 4 may be defined in a plane that is transverse to the filter axis 101. The shield openings 174 may have any suitable shape, dimensions, and quantity (e.g., they may be uniform or non-uniform, patterned or non-patterned, etc.).

[0098] Each louver 170 of the one or more louvers 170 may be canted relative to the filter axis 101 (FIG. 5) such that pulsed gas entering the sleeve-shield volume 164 through the discharge outlet 184 is directed outward (e.g., radially outward relative to filter axis 101) towards the inner sleeve 106. This may advantageously guide the pulsed gas outwards from the inner filter 110 towards the outer filter 112, protecting the inner filter 110 and more efficiently cleaning the outer filter 112. The louvers 170 may have any suitable shape, dimensions, and quantity (e.g., they may be uniform or non-uniform, patterned or non-patterned, etc.). The louvers 170 may define a louver axis 116 (FIG. 5) that is canted relative to the filter axis 101 by an angle a (alpha). The angle a (alpha) may be any angle greater than 0 degrees and less than 180 degrees. In one or more embodiments, the angle a (alpha) may be 150 degrees or less, 120 degrees or less, 90 degrees or less, 60 degrees or less, or 45 degrees or less. Further, the louvers 170 and the shield

-n- openings 174 may, in one or more embodiments, be combined with perforations or any other configuration or construction that protects the inner filter 110 during gas pulses.

[0099] In one or more embodiments, the size and/or spacing of the one or more shield openings 174 changes when moving away from the discharge outlet 184 along the filter axis 101 (FIG. 7). This may advantageously control the pulsed gas to more efficiently and/or more effectively clean the outer filter 112 and the air cleaner system 100 as a whole. For example, as illustrated in FIG. 7, the shield openings 174 become larger in a direction parallel to the filter axis 101 in a direction along the filter axis 101 away from the discharge outlet 184. Larger openings may advantageously allow for more air to filter through the inner filter 110 but may also create a vacuum against the inner filter 110 created by the pulsed gas. Thus, larger openings may be more advantageous farther away from the discharge outlet 184, because there is less risk of creating a vacuum, and this allows for more efficient filtering of air through the system.

[0100] In one or more embodiments, the filter shield 108 may be configured to control passage of gas (e.g., from the dirty air inlet towards the clean air outlet) such that a majority of gas entering the air cleaner system passes through the inner filter 110.

[0101] The shield second end 152 may be coupled to the housing end cap 114 (see C of FIG. 5 schematically demonstrating where the filter shield 108 may be coupled to the housing end cap 114). As a result, the filter shield 108 may be axially located (e.g., along the filter axis 101) relative to the inner filter 110.

[0102] Outer Sleeve

[0103] Unless otherwise noted herein, for each embodiment described herein, the elements as described with system 100 may be used for each and any of the systems herein (e.g., 200, 300, 400, 500, 600). The reference number for an element may change between systems by the hundreds (e.g., inner filter 110, 210, 310, etc.), but unless otherwise noted herein, the description remains unchanged from the original description with reference to system 100.

[0104] The shield 208 of the system 200 may be positioned in the inter-filter volume between the inner filter 210 and the outer filter 212. The shield 208 and the outer filter 212 may define a shield-outer filter volume within the inter-filter volume. The discharge outlet (not shown) may discharge into the shield-outer filter volume.

[0105] The air cleaner system 200 further includes an outer sleeve 207 (FIGS. 8-9). The outer sleeve 207 may be positioned external to the outer filter 212 and between the outer filter 212 and the dirty air inlet 204.

[0106] In one or more embodiments, the outer sleeve 207 may extend along the filter axis 201 away from the clean air outlet 218 towards the outer filter second end. The outer sleeve 207 may extend along the filter axis 201 such that the outer sleeve 207 extends from an outer sleeve first end 242 to an outer sleeve second end 244 (FIG. 8). The outer sleeve first end 242 may be coupled to the housing 202 (e.g., 202-1, 202-2), or to the outer filter 212, proximate the first end of outer filter 212. The outer sleeve second end 244 may be located anywhere between the first ends of the inner and outer filters 210, 212, respectively, and the housing end cap 214 such that the outer sleeve 207 defines an outer sleeve length. The outer sleeve length may be less than half of the outer filter length, half of the outer filter length, or more than half of the outer filter length. The outer sleeve length may be less than half of the inner filter length, half of the inner filter length, or more than half of the inner filter length. The outer sleeve length may be less than half of the housing length, half of the housing length, or more than half of the housing length.

[0107] In one or more embodiments, the outer sleeve second end 244 may be located between the first end and the second ends 234, 236 of the outer filter 212. Optionally, the outer sleeve second end 244 may be located closer to the second end 236 of the outer filter 212 than the first end 234 of the outer filter 212.

[0108] In one or more embodiments, the outer sleeve 207 has a length sufficient to prevent or limit deposition of particulate on the exterior surface of the outer filter 212. Without the outer sleeve 207, the dirty air entering the dirty air inlet 204 may introduce particulate and other matter on the exterior surface of the outer filter 212 that could damage the outer filter 212 or reduce the system’s 200 cleaning efficiency and/or effectivity. The outer sleeve 207 may advantageously prevent or limit such damage by catching or redistributing any particulate.

[0109] In one or more embodiments, the outer sleeve 207 may be fixedly coupled or integral with the inner filter 210 and/or the outer filter 212. This may advantageously ensure that the outer sleeve 207 is present as the inner filter 210 and/or outer filter 212 is installed, proper sizing of the various parts is ensured, proper placement of the various parts is ensured, maintaining the position of the various parts after installation of the filters 210, 212 in the housing 202 is ensured, etc. In alternative embodiments, the outer sleeve 207 may be removably couplable to the inner filter 210 and/or outer filter 212. This may advantageously allow for the same outer sleeve 207 to be re-used with new or replacement inner filters 210 and/or outer filters 212.

[0110] Additionally, the outer sleeve 207 may extend along (e.g., be concentric to) the inner filter 210 for the sleeve length, measured along the filter axis 201. For example, a majority of the outer sleeve 207 may be shaped such that the outer sleeve 207 is coextensive with the outer filter 212. Specifically, at least a portion of the outer sleeve 207 may be spaced a gap distance away from the outer filter 212 such that the outer sleeve 207 and the outer filter 212 define an outer sleeveouter filter volume. The outer sleeve-outer filter volume may allow for the access of gas dispersed therethrough (e.g., air being filtered through the filter media, pulses of gas from, e.g., the pulse cleaning apparatus, etc.).

[0111] The outer sleeve 207 may be constructed of any suitable material or materials. For example, the outer sleeve 207 may include (e.g., be formed of) one or more materials such as, e.g., steel, aluminum, plastic, etc. Further, the outer sleeve 207 may be impermeable to gas/air (e.g., include no openings in the outer sleeve 207). In other embodiments, the outer sleeve 207 may include one or more sleeve openings 172 (e.g., illustrated in FIG. 7) through which fluid may pass. The sleeve openings 172 may advantageously improve the system performance (e.g., by allowing any particulate on the external surface of the outer filter 212 to freely move off of the outer filter 212 without impinging on the outer sleeve 207, etc.). The sleeve openings 172 may be spaced apart along the filter axis 201. The sleeve openings 172 may have any suitable shape, dimensions, and quantity (e.g., they may be uniform or non-uniform, patterned or non-patterned, etc.).

[0112J In one or more embodiments, the size and/or spacing of the one or more sleeve openings 174 changes when moving away from the discharge outlet 284 along the filter axis 201. This may advantageously control the pulsed gas to more efficiently and/or more effectively clean the outer filter 212 and the air cleaner system 200 as a whole. For example, as illustrated in FIG. 7, the sleeve openings 174 become larger in a direction parallel to the filter axis 201 in a direction along the filter axis 201 away from the discharge outlet 184. Larger openings may advantageously allow for more air to pulse through the system during pulse cleaning, but may also allow more particulate to enter the system 200. Thus, larger openings may be more advantageous farther away from the center of the dirty air inlet 204, because there is less risk of allowing particulate ingress, and this allows for more efficient pulse cleaning of air through the system 200.

[0113] In one or more embodiments, the outer sleeve 207 may be configured to control passage of gas (e.g., from the pulse cleaning apparatus 203-1 and 203-2) such that a majority of gas exiting the dirty air inlet 204 during pulse cleaning of the system 100 exits the outer sleeve-outer volume through the outer sleeve second end 244.

[0114] The outer sleeve second end 244 may be coupled to the housing end cap 214 (not shown). As a result, the outer sleeve 207 may be axially located (e.g., along the filter axis 201) relative to the inner filter 210. Optionally, the outer sleeve 207 may be attached to the housing end cap 214.

[0115] Segmented Annulus [0116] The discharge outlet 284 may be partially defined by the duct 280. The duct 280 may operatively couple the inner filter 210 to the housing 202. Such operative coupling may advantageously ensure proper installation and placement of the inner filter 210 relative to the rest of the system 200. The duct 280 may be shaped to define the discharge outlet 284 to optimize cleaning effectivity and efficiency of the system 200. The duct 280 may be shaped to increase the speed of the air moving from the pulse cleaning apparatus and into the inter-filter volume 260. Increasing the air speed may advantageously improve cleaning of the outer filter 212.

[0117] The duct 280 (FIGS. 8-12) of the air cleaner system 200 further includes one or more fins 282 (FIGS. 10-12). The fin(s) 282 may advantageously segment the discharge outlet 284 annulus into two or more portions such that air pulses may be selectively controlled. Selective control of the pulse cleaning apparatuses 203-1, 203-2 may advantageously allow for energy saving and more efficient cleaning, because an apparatus may be selected to release a pulse of air when needed to clean a specific portion of the outer filter 212, without using all of the apparatuses 203-1, 203-2.

[0118] The fin(s) 282 may extend from a first end 285 to a second end 286. The fin(s) 282 may include an outer portion 288 and an inner portion 290. The fin(s) may be sized to partially or fully block the discharge outlet annulus (and thus, segment the discharge outlet annulus into sections). When the fin(s) 282 are designed to partially block the discharge outlet annulus, air may be allowed to impinge upon the fin(s) 282 and flow along and/or around the fin(s) 282 and out towards the outer filter 212, which may be optimized to clean the system 200. Alternatively, and as shown, when the fin(s) 282 are designed to fully block the discharge outlet annulus, air may be allowed to impinge upon the fin(s) 282 and then must flow along the fin(s) 282 and out towards the outer filter 212, which may be optimized to clean the system 200.

[0119] The fin(s) 282 may be constructed of any suitable material or materials. For example, the fin(s) 282 may include (e.g., be formed of) one or more materials such as, e.g., steel, aluminum, plastic, etc. Further, the fin(s) 282 may be impermeable to gas/air (e.g., include no openings in the fin(s) 282). In other embodiments, the fin(s) 282 may include one or more fin openings through which fluid may pass. The fin openings may advantageously improve the system performance (e.g., by reducing pressure drop within the inter-filter volume, etc.). The fin openings may have any suitable shape, dimensions, and quantity (e.g., they may be uniform or non-uniform, patterned or non-pattemed, etc.).

[0120] In one or more embodiments, the size and/or spacing of the fin openings changes when moving away from the discharge outlet 284 along the filter axis 201. This may advantageously control the pulsed gas to more efficiently and/or more effectively clean the outer filter 212 and the air cleaner system 200 as a whole. For example, the fin openings may become larger in a direction parallel to the filter axis 201 in a direction along the filter axis 201 away from the discharge outlet 284.

[0121] Elliptical discharge outlet annulus

[0122] As illustrated in FIGS. 13-15, an air cleaner system 300 includes a housing 302 (e.g., 302-1, 302-2), housing end cap 314, pulse cleaning apparatuses (303-1 , 303- 2), filter axis 301, discharge outlet 384, dirty air outlet 304, inner filter 310, outer filter 312, duct 380, and outer sleeve 307, each as described herein in other system embodiments (e.g., systems 100, 200, 400, 500, 600).

[0123] The discharge outlet 384 may be partially defined by a duct 380. The duct 380 may operatively couple the inner filter 310 to the housing 302. Such operative coupling may advantageously ensure proper installation and placement of the inner filter 310 relative to the rest of the system 300. In alternative embodiments, the duct 380 may be integral with the second housing section 302-2, which may advantageously reduce system complexity. The duct 380 may be shaped to define the discharge outlet 384 to optimize cleaning effectivity and efficiency of the system 300. For example, an elliptical annulus may be formed, as clearly shown in FIG. 15. An elliptical annulus may advantageously allow for more efficient and effective cleaning of the system 300, because the elliptical annulus shape may result in more uniform air distribution around and along the axis 301.

[0124] The elliptical annulus may be incorporated into any system (e.g., 100-600) described herein. For example, the elliptical annulus may be segmented using the fins as described herein with respect to system 200. Additionally, the system 300 is not illustrated with an inner sleeve, but that element could be used with this system 300. Such elements could extend along the axis 301, or could extend parallel to the external surface of the inner filter 310. In one or more embodiments, one or more of the inter-filter volume, sleeve-inner filter volume, and sleeve-shield volume includes a cylindrical volume (e.g., an elliptical cylindrical volume, etc.), a conical volume, an annular volume, etc., or any combination thereof.

[0125] Conical Cylindrical Filters

[0126] As illustrated in FIGS. 16-17, an air cleaner system 400 includes a housing 402 (e.g., 402-1, 402-2), housing end cap 414, pulse cleaning apparatuses (403-1, 403- 2), filter axis 401, discharge outlet 484, dirty air outlet 404, inner filter 410, outer filter 412, duct 480, and outer sleeve 407, each as described herein in other system embodiments (e.g., systems 100, 200, 300, 500, 600).

[0127] As illustrated in FIGS 16-17, the inner filter 410 may be in the form of a conical cylindrical inner filter, with a larger diameter towards the clean air outlet 418 and a smaller diameter towards the housing end cap 414. The outer filter 412 may be in the form of a conical cylindrical outer filter, with a larger diameter towards the clean air outlet 418 and a smaller diameter towards the housing end cap 414. Such conical cylindrical filters may advantageously be easy to keep clean, since pulsed gas used to clean the filters may be directed outwards from the filters. Thus, pulsed gas may be directed from the inner filter 410 towards the outer filter 412, for example, or from the outer filter 412 towards the housing 402, for another example. The inner cone shape 415 may help to direct pulsed gas outwards from the filters 410, 412. [0128] Additionally, the system 400 is not illustrated with an inner sleeve or a shield, but those elements could be used with this system 400. Such elements could extend along the axis 401, or could extend parallel to the external surface of the inner filter 410. In one or more embodiments, one or more of the inter-filter volume, sleeve-inner filter volume, and sleeve-shield volume includes a cylindrical volume (e.g., a circular cylindrical volume, an elliptical cylindrical volume, etc.), a conical volume, an annular volume, etc., or any combination thereof.

[0129] Expansion Chamber With Nozzle

[0130] As illustrated in FIGS. 18-21, an air cleaner system 500 includes a housing 502 (e.g., 502-1, 502-2), housing end cap 514, pulse cleaning apparatus 503-1 (further apparatuses not shown in these views but understood to be optionally included), filter axis 501, discharge outlet 584, dirty air outlet 504, inner filter 510, outer filter 512, duct 580, and outer sleeve 507, each as described herein in other system embodiments (e.g., systems 100, 200, 300, 400, 600).

[0131] As illustrated in FIGS. 20-21, the pulse cleaning apparatus 503-1 is made up of a pulse solenoid 511 and a pulse valve 513, which are coupled to the housing via a valve connection. The system 500 further includes an expansion chamber 515. The expansion chamber 515 may define an annulus shape around the inner filter 510. The system 500 may further include an inner shield 521. The inner shield 521 may extend from a point axially external to the annulus pulse outlet 523 to the inner baffle 586-1. The inner shield 521 may advantageously protect the outer filter 512 from the pulsed gas, and may also advantageously be formed to shape the expansion chamber 515. In embodiments where the inner shield 521 also shapes the expansion chamber 515, assembly of the system 500 may be more efficient. In alternative embodiments (e.g., as shown in FIG. 21), the system 500 does not include the inner shield. This may advantageously simplify the system 500, may reduce the overall size of the system 500, and may allow more efficient assembly of the system 500. However, without the inner shield, the outer filter 512 may be subjected to the pulsed gas. [0132] The system may further include a snap-in yoke 525 (dashed line). The yoke 525 may secure the filter assembly in the absence of a protective cover at the end of the filters 510, 512 near the clean air outlet.

[0133] The expansion chamber 515 may lead to a nozzle 519 (FIGS. 18-21). The nozzle 519 is created by an inner baffle 586-1 and an outer baffle 586-2. The nozzle 519 may define a diameter that decreases from the discharge outlet 518 towards the inter-filter volume. The nozzle 519 may advantageously increase the speed of the airflow from the expansion chamber 515 to the interior of the system, helping to better clean the filters 512, 510. The inner baffle 586-1 may be longer than the outer baffle 586-2. A longer inner baffle 586-1 may advantageously direct pulsed gas towards the outer filter 512, promoting cleaning efficiency and effectivity.

[0134] The system 500 may further include a support structure 509 (FIG. 18). The support structure 509 may be positioned within the second housing section 502-2. The support structure 509 may advantageously strengthen the second housing section 502-2 and/or the duct 580. The support structure 509 may include one or more arms that extend across a portion of the cross-section of the housing section 502-2. The one or more arms may extend generally perpendicular to the filter axis 501 (FIG. 19).

[0135] The system may further include a seal 517, which may advantageously protect the inner filter 510 from the pulsed gas. The seal 517 may be integral with the inner filter 510. The seal 517 may be formed out of a urethane material. The seal 517 may be operatively coupled to the clean air outlet using, for example, friction forces or intermediate structures (e.g., a cylindrical bracket or duct). In one or more embodiments, the seal 517 may be operatively coupled to the inner baffle 586-1. In such embodiments, the seal 517 and the inner baffle 586-1 can be assembled with the inner filter 510. In one or more embodiments, the inner filter 510 may be operatively coupled to the inner baffle 586-1. In such embodiments, the inner baffle 586-1 can be assembled with the inner filter 510. In one or more embodiments, the outer filter 512 may be operatively coupled to the outer baffle 586-2. In such embodiments, the outer baffle 586-2 can be assembled with the outer filter 512.

[0136] Expansion Chamber With Baffle

[0137] As illustrated in FIGS. 22-25, an air cleaner system 600 includes a housing 602 (e.g., 602-1, 602-2), housing end cap 614, pulse cleaning apparatus 603-1 (further apparatuses not shown in these views but understood to be optionally included), filter axis 601, discharge outlet 684, dirty air outlet 604, inner filter 610, outer filter 612, shield 608, duct 680, internal cone shape 61 , and outer sleeve 607, each as described herein in other system embodiments (e.g., systems 100, 200, 300, 400, 500).

[0138] As illustrated in FIG. 22, the inner filter 610 may be in the form of a circular cylindrical inner filter, as described herein. Such a circular form may advantageously reduce complexity in the system and facilitate ease of installation.

[0139] The system 600 differs from the other system herein in that the shield 608 includes louvers from a point proximate the inner filter 610 towards the housing end cap 614. Thus, the pulsed gas is directed away from the inner filter 610 while simultaneously facilitating system simplicity since the louvers are not required along the entire length of the shield 608.

[0140] The system 600 further includes a baffle 609. The baffle 609 is positioned proximate the discharge outlet 684 and is annular in shape around the axis 601. The baffle 609 may be coupled to the discharge outlet 618 and may extend away from the inner filter 610. The baffle 609 may advantageously direct air toward the interior surface of the outer filter 612.

[0141] As illustrated in FIGS. 23-25, the shield 608 is solid (e.g., without louvers) around the inner filter 610. Thus, no inner sleeve is required to protect the inner filter 610, since the shield 608 is solid. In alternative embodiments, the shield 608 may have one or more openings around the inner filter 610 to facilitate more efficient and effective air filtration. The one or more openings may be sized to reduce restriction(s) to airflow through the system 600. The one or more openings may be sized such that the pulsed gas is directed outward towards the outer filter 612, and further such that the pulsed gas is maintained outside of the shield 608 (and outside of any louvers).

[0142] Also as illustrated in FIGS. 23-25, the inner filter 610 may be in the form of a conical cylindrical inner filter, with a larger diameter towards the housing end cap 614 and a smaller diameter towards the clean air outlet 618. Such conical cylindrical filters may advantageously increase filter surface area for air flowing towards the clean air outlet 618. Since the inner filter 610 is protected by the shield 608, the inner filter can be shaped to increase surface area without increasing the chance that particulate clogs the inner filter 610.

[0143] As illustrated in FIGS. 24-25, the inner filter 610 may be positioned such that the inner filter first end 630 is located within the second housing section 602-2 (instead of proximate both the first and second housing sections 602-1, 602-2). In other words, the inner filter 610 may be positioned closer to the clean air outlet 618 than the pulse cleaning apparatus(es) 603-1, 603-2. Thus, the inner filter 610 is mounted to the housing 602 at an intermediate point on the inner filter 610. A mount 611 may be used to mount the inner filter 610 to the housing 602. Such a mounted configuration may advantageously allow airflow more directly from the outer filter 612 towards the axis 601 prior to flowing into the inner filter 610, allowing efficient and effective airflow filtration through the system 600.

[0144] As illustrated in FIGS. 22 and 25, air pressure generator 605-1 and 605-2 may be positioned proximate the discharge outlet 684 and may generate the pulsed gas used to clean the system 600. Any of the systems described herein may use air pressure generators to generate the pulsed gas used to the clean the systems.

[0145] Exemplary Embodiments:

[0146] Example Exl : An air cleaner system including: a housing including a dirty air inlet and a clean air outlet; an inner filter located in the housing, the inner filter sealed about the clean air outlet such that dirty air entering the housing through the dirty air inlet must pass through the inner filter before entering the clean air outlet; an outer filter located in the housing, the outer filter including a first end sealed inside the housing proximate the clean air outlet and a second end located distal from the first end along a filter axis extending through the first end, the second end, and the clean air outlet, where dirty air entering the housing through the dirty air inlet must pass through the outer filter before passing through the inner filter; a sleeve positioned in an inter-filter volume between the inner filter and the outer filter, the sleeve and the inner filter defining a sleeve-inner filter volume within the inter-filter volume; a shield positioned in the sleeve-inner filter volume between the sleeve and the inner filter, the shield and the sleeve defining a sleeve-shield volume between the sleeve and the shield; and a discharge outlet opening into the sleeve-shield volume, where pulsed gas entering the sleeve-shield volume through the discharge outlet moves along the filter axis through the sleeve-shield volume; where the shield includes a one or more shield openings spaced apart along the filter axis, the one or more shield openings configured to allow air to pass from the sleeve-shield volume to the inner filter.

[0147] Example Ex2: A system according to Exl, where the shield includes one or more louvers and wherein the one or more shield openings are located between the one or more louvers when moving along the filter axis, and, optionally, wherein the one or more shield openings face away from the discharge outlet.

[0148] Example Ex3: A system according to any of Exl-Ex2, where each louver of the one or more louvers is canted relative to the filter axis such that pulsed gas entering the sleeve-shield volume through the discharge outlet is directed outward towards the sleeve.

[0149] Example Ex4: A system according to any of Exl-Ex3, where the size and/or spacing of the one or more shield openings changes when moving away from the discharge outlet along the filter axis.

[0150] Example Ex5: A system according to any of Exl-Ex4, where the sleeve extends along the filter axis away from the clean air outlet towards the second end of the outer filter, and, optionally, where the sleeve is sealed about the clean air outlet proximate the first end of the outer filter.

[0151] Example Ex6: A system according to any of Exl-Ex5, where the shield extends along the filter axis away from the clean air outlet towards the second end of the outer filter.

[0152] Example Ex7: A system according to any of Exl-Ex6, where the sleeve extends along the filter axis away from a sleeve first end proximate the clean air outlet to a sleeve second end, where the sleeve second end is located between the first end and the second end of the outer filter, and, optionally, where the sleeve second end is located closer to the second end of the outer filter than the first end of the outer filter.

[0153] Example Ex8: A system according to any of Exl-Ex7, where the shield extends along the filter axis away from a shield first end proximate the clean air outlet to a shield second end, where the shield second end is located between the first end and the second end of the outer filter, and, optionally, where the shield second end is located closer to the second end of the outer filter than the first end of the outer filter.

[0154] Example Ex9: A system according to any of Exl-Ex8, where the sleeve extends along the filter axis away from the sleeve first end to the sleeve second end, and the shield extends along the filter axis away from the shield first end to the shield second end, where the shield second end is located between the sleeve second end and the second end of the outer filter.

[0155] Example ExlO: A system according to any of Exl-Ex9, where the sleeve includes one or more sleeve openings spaced apart along the filter axis, the one or more sleeve openings configured to allow air entering the inter-filter volume through the outer filter to pass through the sleeve into the sleeve-shield volume and, optionally, where the size and/or spacing of the one or more shield openings changes when moving away from the discharge outlet along the filter axis. [0156] Example Exl 1 : A system according to any of Exl-Exl O, where the shield is coupled to the housing proximate the clean air outlet such that the shield remains attached to the housing after removal of the inner filter.

[0157] Example Exl2: A system according to any of Exl-Exl 1, where the shield is coupled to the inner filter such that the shield is removed from the housing with removal of the inner filter from the housing.

[0158] Example Exl3: A system according to any of Exl-Exl2, where the sleeve is coupled to the housing proximate the discharge outlet.

[0159] Example Exl4: A system according to any of Exl-Exl 3, where the housing includes an end cap proximate the second end of the outer filter, and where, optionally, one or both of the sleeve and the shield are attached to the end cap.

[0160] Example Exl5: A system according to any of Exl-Exl4, where the discharge outlet includes an annular discharge outlet.

[0161] Example Exl6: A system according to any of Exl-Exl5, where one or more of the inter-filter volume, sleeve-inner filter volume, and sleeve-shield volume includes a cylindrical volume.

[0162] Example Ex 17: A system according to any of Exl -Exl 6, where the outer filter includes a cylindrical filter extending along the filter axis from the first end to the second, where, optionally, the outer filter includes a circular cylindrical outer filter.

[0163] Example Exl8: A system according to any of Exl-Exl7, where the inner filter includes a cylindrical filter extending along the filter axis, where, optionally, the inner filter includes a circular cylindrical inner filter.

[0164] Example Ex 19: An air cleaner system including a housing including a dirty air inlet and a clean air outlet. The system further includes an inner filter located in the housing, the inner filter sealed about the clean air outlet such that dirty air entering the housing through the dirty air inlet must pass through the inner filter before entering the clean air outlet. The system further includes an outer filter located in the housing, the outer filter comprising a first end sealed inside the housing proximate the clean air outlet and a second end located distal from the first end along a filter axis extending through the first end, the second end, and the clean air outlet. Dirty air entering the housing through the dirty air inlet must pass through the outer filter before passing through the inner filter. The system further includes a shield positioned in an inter-filter volume between the inner filter and the outer filter, the shield at least partially surrounding the inner filter along the circumference of the inner filter, and the shield and the outer filter defining a shield-outer filter volume within the inter-filter volume. The system further includes a discharge outlet opening into the shield-outer filter volume. Pulsed gas entering the shield-outer filter volume through the discharge outlet moves along the filter axis through the shield-outer filter volume.

[0165] Example Ex 20: A system according to any of Exl-Exl9, where the shield fully surrounds the inner filter along the circumference of the inner filter.

[0166] Example Ex 21 : A system according to any of Ex 1-20, further including a duct coupled to the clean air outlet and defining a cross-sectional shape of the clean air outlet proximate the inner filter, and where the duct partially defines the discharge outlet.

[0167] Example Ex 22: A system according to any of Exl-Ex21, where the clean air outlet defines a cross-sectional shape proximate the inner filter, and wherein the clean air outlet partially defines the discharge outlet.

[0168] Example Ex 23: A system according to any of Exl-Ex22, further including an inner sleeve positioned in the inter-filter volume between the shield and the outer filter, where the discharge outlet opens into a sleeve-shield volume between the inner sleeve and the shield, and where pulsed gas entering the sleeve-shield volume through the discharge outlet moves along the filter axis through the sleeve-shield volume.

[0169] Example Ex 24: A system according to any of Exl-Ex23, further including an outer sleeve positioned between the outer filter and the dirty air inlet.

[0170] Example Ex 25: A system according to any of Exl-Ex24, where the shield includes one or more shield openings spaced apart along the filter axis, the one or more shield openings configured to allow air to pass from the sleeve-shield volume to the inner filter.

[0171] Example Ex 26: A system according to any of Exl-Ex25, where the shield includes one or more louvers and where the one or more shield openings are located between the one or more louvers when moving along the filter axis, and, optionally, where the one or more shield openings face away from the discharge outlet.

[0172] Example Ex 27: A system according to any of Exl-Ex26, where each louver of the one or more louvers is canted relative to the filter axis such that pulsed gas entering the sleeve-shield volume through the discharge outlet is directed outward towards the inner sleeve.

[0173] Example Ex 28: A system according to any of Exl-Ex27, where the size and/or spacing of the one or more shield openings changes when moving away from the discharge outlet along the filter axis.

[0174] Example Ex 29: A system according to any of Exl-Ex28, where the inner sleeve extends along the filter axis away from the clean air outlet towards the second end of the outer filter, and, optionally, where the inner sleeve is sealed about the clean air outlet proximate the first end of the outer filter.

[0175] Example Ex 30: A system according to any of Exl-Ex29, where the shield extends along the filter axis away from the clean air outlet towards the second end of the outer filter.

[0176] Example Ex 31 : A system according to any of Exl-Ex30, where the inner sleeve extends along the filter axis away from an inner sleeve first end proximate the clean air outlet to an inner sleeve second end, where the inner sleeve second end is located between the first end and the second end of the outer filter, and, optionally, where the inner sleeve second end is located closer to the second end of the outer filter than the first end of the outer filter.

[0177] Example Ex 32: A system according to any of Exl-Ex31, where the shield extends along the filter axis away from a shield first end proximate the clean air outlet to a shield second end, where the shield second end is located between the first end and the second end of the outer filter, and, optionally, where the shield second end is located closer to the second end of the outer fdter than the first end of the outer filter.

[0178] Example Ex 33: A system according to any of Exl-Ex32, where the inner sleeve extends along the filter axis away from the inner sleeve first end to the inner sleeve second end, and the shield extends along the filter axis away from the shield first end to the shield second end, where the shield second end is located between the inner sleeve second end and the second end of the outer filter.

[0179] Example Ex 34: A system according to any of Exl-Ex33, where the inner sleeve comprises one or more sleeve openings spaced apart along the filter axis, the one or more sleeve openings configured to allow air entering the inter-filter volume through the outer filter to pass through the inner sleeve into the sleeve-shield volume and, optionally, where the size and/or spacing of the one or more shield openings changes when moving away from the discharge outlet along the filter axis.

[0180] Example Ex 35: A system according to any of Exl-Ex34, where the shield is coupled to the housing proximate the clean air outlet such that the shield remains attached to the housing after removal of the inner filter.

[0181] Example Ex 36: A system according to any of Exl-Ex35, where the shield is coupled to the inner filter such that the shield is removed from the housing with removal of the inner filter from the housing.

[0182] Example Ex 37: A system according to any of Exl-Ex36, where the inner sleeve is coupled to the housing proximate the discharge outlet.

[0183] Example Ex 38: A system according to any of Exl-Ex37, where the housing includes an end cap proximate the second end of the outer filter.

[0184] Example Ex 39: A system according to any of Exl-Ex,38, where, optionally, one or both of the inner sleeve and the shield are attached to the end cap.

[0185] Example Ex 40: A system according to any of Exl-Ex39, where the discharge outlet includes an annular discharge outlet.

[0186] Example Ex 41 : A system according to any of Exl-Ex40, where the inter-filter volume includes at least one of: a circular cylindrical volume, an elliptical cylindrical volume, and a conical volume. [0187] Example Ex 42: A system according to any ofExl-Ex41 , where the sleeve-shield volume includes at least one of: a circular cylindrical volume, an elliptical cylindrical volume, and a conical volume.

[0188] Example Ex 43: A system according to any of Exl-Ex42, where an inner sleeve- inner fdter volume includes at least one of: a circular cylindrical volume, an elliptical cylindrical volume, and a conical volume.

[0189] Example Ex 44: A system according to any of Exl-Ex43, where the outer fdter includes a cylindrical fdter extending along the fdter axis from the first end to the second, where, optionally, the outer fdter includes one or more of: a circular cylindrical outer fdter and a conical cylindrical outer fdter.

[0190] Example Ex 45: A system according to any of Exl-Ex44, where the inner fdter includes a cylindrical fdter extending along the fdter axis, where, optionally, the inner fdter includes one or more of: a circular cylindrical inner fdter and a conical cylindrical inner fdter.

[0191] Example Ex 46: A system according to any of Exl-Ex45, further including a housing end cap coupled to the housing distal from the clean air outlet.

[0192] Example Ex 47: A system according to any of Exl-Ex46, where when the outer fdter is a conical cylindrical outer fdter, the conical cylindrical outer fdter defines a larger diameter proximate the discharge outlet and a smaller diameter proximate the housing end cap.

[0193] Example Ex 48: A system according to any of Exl-Ex47, where when the outer fdter is a conical cylindrical outer fdter, the conical cylindrical outer fdter defines a larger diameter proximate the housing end cap and a smaller diameter proximate the discharge outlet.

[0194] Example Ex 49: A system according to any of Exl-Ex48, where when the inner fdter is a conical cylindrical inner fdter, the conical cylindrical inner fdter defines a larger diameter proximate the discharge outlet and a smaller diameter proximate the housing end cap.

[0195] Example Ex 50: A system according to any of Exl-Ex49, where when the inner fdter is a conical cylindrical inner fdter, the conical cylindrical inner fdter defines a larger diameter proximate the housing end cap and a smaller diameter proximate the discharge outlet.

[0196] Example Ex 51 : A system according to any of Exl-Ex50, further including an inner baffle and an outer baffle, the inner baffle and the outer baffle coupled to the discharge outlet and forming a nozzle extending from the discharge outlet into the inter-filter volume, where the nozzle defines a diameter that decreases from the discharge outlet towards the inter-filter volume.

[0197] Example Ex 52: A system according to any of Exl-Ex51, further including a baffle coupled to the discharge outlet and extending away from the inner filter.

[0198] Example Ex 53: A system according to any of Exl-Ex52, further including a pulse cleaning apparatus coupled to the housing proximate the clean air outlet, and where the inner filter is positioned closer to the clean air outlet than the pulse cleaning apparatus.

[0199] Example Ex 54: An air cleaner system including a housing including a dirty air inlet and a clean air outlet. The system further includes an inner filter located in the housing, the inner filter sealed about the clean air outlet such that dirty air entering the housing through the dirty air inlet must pass through the inner filter before entering the clean air outlet. The system further includes an outer filter located in the housing, the outer filter including a first end sealed inside the housing proximate the clean air outlet and a second end located distal from the first end along a filter axis extending through the first end, the second end, and the clean air outlet, where dirty air entering the housing through the dirty air inlet must pass through the outer filter before passing through the inner filter, where the inner filter and the outer filter define an inter-filter volume therebetween. The system further includes a discharge outlet opening into the inter-filter volume, where pulsed gas entering the inter-filter volume through the discharge outlet moves along the filter axis through the inter-filter volume.

[0200] Example Ex 55: A system according to any of Exl-Ex54, further including a shield positioned in the inter-filter volume, the shield partially surrounding the inner filter along the circumference of the inner filter, and the shield and the outer filter defining a shield-outer filter volume within the inter-filter volume, where the discharge outlet opens into the shield-outer fdter volume, where pulsed gas entering the shield-outer filter volume through the discharge outlet moves along the filter axis through the shield-outer filter volume.

[0201] Example Ex56: A filter element including a filter media having a first end and a second end. The filter element further includes a first, open end cap coupled to the first end of the filter media. The filter element further includes a second end cap coupled to the second end of the filter media. The filter element further includes a baffle coupled to the first open end cap, the baffle having a portion projecting radially outward from the filter media at an angle greater than zero.

[0202] In the preceding description, reference is made to the accompanying set of drawings that form a part hereof and in which are shown by way of illustration several specific embodiments. It is to be understood that other embodiments are contemplated and may be made without departing from (e.g., still falling within) the scope of the present disclosure. The preceding detailed description, therefore, is not to be taken in a limiting sense. All scientific and technical terms used herein have meanings commonly used in the art unless otherwise specified. The definitions provided herein are to facilitate understanding of certain terms used frequently herein and are not meant to limit the scope of the present disclosure.

[0203] Unless otherwise indicated, all numbers expressing feature sizes, amounts, and physical properties used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless indicated to the contrary, the numerical parameters set forth in the foregoing specification and attached claims are approximations that can vary depending upon the desired properties sought to be obtained by those skilled in the art utilizing the teachings disclosed herein.

[0204] The recitation of numerical ranges by endpoints includes all numbers subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5) and any range within that range.

[0205] As used in this specification and the appended claims, the singular forms “a”, “an”, and “the” encompass embodiments having plural referents, unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise.

[0206] As used herein, “have”, “having”, “include”, “including”, “comprise”, “comprising” or the like are used in their open-ended sense, and generally mean “including, but not limited to”. It will be understood that “consisting essentially of’, “consisting of’, and the like are subsumed in “comprising,” and the like.

[0207] It is noted that terms such as “top”, “bottom”, “above, “below”, etc. may be used in this disclosure. These terms should not be construed as limiting the position or orientation of a structure, but should be used as providing spatial relationship between the structures.

[0208] All references and publications cited herein are expressly incorporated herein by reference in their entirety into this disclosure, except to the extent they may directly contradict this disclosure. Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and/or equivalent implementations can be substituted for the specific embodiments shown and described without departing from the scope of the present disclosure. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, it is intended that this disclosure be limited only by the claims and the equivalents thereof. The disclosed embodiments are presented for purposes of illustration and not limitation.

Claims

CLAIMS What is claimed:

1. An air cleaner system comprising: a housing comprising a dirty air inlet and a clean air outlet; an inner fdter located in the housing, the inner fdter sealed about the clean air outlet such that dirty air entering the housing through the dirty air inlet must pass through the inner fdter before entering the clean air outlet; an outer fdter located in the housing, the outer fdter comprising a first end sealed inside the housing proximate the clean air outlet and a second end located distal from the first end along a fdter axis extending through the first end, the second end, and the clean air outlet, wherein dirty air entering the housing through the dirty air inlet must pass through the outer fdter before passing through the inner fdter; a shield positioned in an inter-filter volume between the inner fdter and the outer fdter, the shield at least partially surrounding the inner fdter along the circumference of the inner fdter, and the shield and the outer fdter defining a shieldouter fdter volume within the inter-filter volume; and a discharge outlet opening into the shield-outer fdter volume, wherein pulsed gas entering the shield-outer fdter volume through the discharge outlet moves along the fdter axis through the shield-outer fdter volume.

2. The air cleaner system according to claim 1, wherein the shield fully surrounds the inner fdter along the circumference of the inner fdter.

3. The air cleaner system according to any one of the preceding claims, further comprising a duct coupled to the clean air outlet and defining a cross-sectional shape of the clean air outlet proximate the inner filter, and wherein the duct partially defines the discharge outlet.

4. The air cleaner system according to any one of the preceding claims, wherein the clean air outlet defines a cross-sectional shape proximate the inner filter, and wherein the clean air outlet partially defines the discharge outlet.

5. The air cleaner system according to any one of the preceding claims, further comprising an inner sleeve positioned in the inter-filter volume between the shield and the outer filter, wherein the discharge outlet opens into a sleeve-shield volume between the inner sleeve and the shield, and wherein pulsed gas entering the sleeveshield volume through the discharge outlet moves along the filter axis through the sleeve-shield volume.

6. The air cleaner system according to any one of the preceding claims, further comprising an outer sleeve positioned between the outer filter and the dirty air inlet.

7. The air cleaner system according to any one of claims 5-6, wherein the shield comprises one or more shield openings spaced apart along the filter axis, the one or more shield openings configured to allow air to pass from the sleeve-shield volume to the inner filter.

8. The air cleaner system according to claim 7, wherein the shield comprises one or more louvers and wherein the one or more shield openings are located between the one or more louvers when moving along the filter axis, and, optionally, wherein the one or more shield openings face away from the discharge outlet.

9. The air cleaner system according to claim 8, wherein each louver of the one or more louvers is canted relative to the filter axis such that pulsed gas entering the sleeve-shield volume through the discharge outlet is directed outward towards the inner sleeve.

10. The air cleaner system according to any one of claims 7-9, wherein the size and/or spacing of the one or more shield openings changes when moving away from the discharge outlet along the filter axis.

11. The air cleaner system according to any one of claims 5-10, wherein the inner sleeve extends along the filter axis away from the clean air outlet towards the second end of the outer filter, and, optionally, wherein the inner sleeve is sealed about the clean air outlet proximate the first end of the outer filter.

12. The air cleaner system according to any one of the preceding claims, wherein the shield extends along the filter axis away from the clean air outlet towards the second end of the outer filter.

13. The air cleaner system according to any one of the claims 5-12, wherein the inner sleeve extends along the filter axis away from an inner sleeve first end proximate the clean air outlet to an inner sleeve second end, wherein the inner sleeve second end is located between the first end and the second end of the outer filter, and, optionally, wherein the inner sleeve second end is located closer to the second end of the outer filter than the first end of the outer filter.

14. The air cleaner system according to any one of the preceding claims, wherein the shield extends along the filter axis away from a shield first end proximate the clean air outlet to a shield second end, wherein the shield second end is located between the first end and the second end of the outer filter, and, optionally, wherein the shield second end is located closer to the second end of the outer filter than the first end of the outer filter.

15. The air cleaner system according to claim 14, wherein the inner sleeve extends along the filter axis away from the inner sleeve first end to the inner sleeve second end, and the shield extends along the filter axis away from the shield first end to the shield second end, wherein the shield second end is located between the inner sleeve second end and the second end of the outer filter.

16. The air cleaner system according to any one of claims 7-15, wherein the inner sleeve comprises one or more sleeve openings spaced apart along the filter axis, the one or more sleeve openings configured to allow air entering the inter-filter volume through the outer filter to pass through the inner sleeve into the sleeveshield volume and, optionally, wherein the size and/or spacing of the one or more shield openings changes when moving away from the discharge outlet along the filter axis.

17. The air cleaner system according to any one of the preceding claims, wherein the shield is coupled to the housing proximate the clean air outlet such that the shield remains attached to the housing after removal of the inner filter.

18. The air cleaner system according to any one of the preceding claims, wherein the shield is coupled to the inner filter such that the shield is removed from the housing with removal of the inner filter from the housing.

19. The air cleaner system according to any one of claims 5-18, wherein the inner sleeve is coupled to the housing proximate the discharge outlet.

20. The air cleaner system according to any one of the preceding claims, wherein the housing comprises an end cap proximate the second end of the outer filter.

21. The air cleaner system according to claim 20 wherein, optionally, one or both of the inner sleeve and the shield are attached to the end cap.

22. The air cleaner system according to any one of the preceding claims, wherein the discharge outlet comprises an annular discharge outlet.

23. The air cleaner system according to any one of the preceding claims, wherein the inter-filter volume comprises at least one of: a circular cylindrical volume, an elliptical cylindrical volume, and a conical volume.

24. The air cleaner system according to any one of claims 5-23, wherein the sleeve-shield volume comprises at least one of: a circular cylindrical volume, an elliptical cylindrical volume, and a conical volume.

25. The air cleaner system according to any one of the preceding claims, wherein an inner sleeve-inner filter volume comprises at least one of: a circular cylindrical volume, an elliptical cylindrical volume, and a conical volume.

26. The air cleaner system according to any one of the preceding claims, wherein the outer filter comprises a cylindrical filter extending along the filter axis from the first end to the second, wherein, optionally, the outer filter comprises one or more of: a circular cylindrical outer filter and a conical cylindrical outer filter.

27. The air cleaner system according to any one of the preceding claims, wherein the inner filter comprises a cylindrical filter extending along the filter axis, wherein, optionally, the inner filter comprises one or more of: a circular cylindrical inner filter and a conical cylindrical inner filter.

28. The air cleaner system according to any one of claims 26-27, further comprising a housing end cap coupled to the housing distal from the clean air outlet.

29. The air cleaner system according to claim 28, wherein when the outer filter is a conical cylindrical outer filter, the conical cylindrical outer filter defines a larger diameter proximate the discharge outlet and a smaller diameter proximate the housing end cap.

30. The air cleaner system according to claim 28, wherein when the outer filter is a conical cylindrical outer filter, the conical cylindrical outer filter defines a larger diameter proximate the housing end cap and a smaller diameter proximate the discharge outlet.

31. The air cleaner system according to claim 28, wherein when the inner filter is a conical cylindrical inner filter, the conical cylindrical inner filter defines a larger diameter proximate the discharge outlet and a smaller diameter proximate the housing end cap.

32. The air cleaner system according to claim 28, wherein when the inner filter is a conical cylindrical inner filter, the conical cylindrical inner filter defines a larger diameter proximate the housing end cap and a smaller diameter proximate the discharge outlet.

33. The air cleaner system according to any one of the preceding claims, further comprising: an inner baffle and an outer baffle, the inner baffle and the outer baffle coupled to the discharge outlet and forming a nozzle extending from the discharge outlet into the inter-filter volume, wherein the nozzle defines a diameter that decreases from the discharge outlet towards the inter-filter volume.

34. The air cleaner system according to any one of the preceding claims, further comprising a baffle coupled to the discharge outlet and extending away from the inner filter.

35. The air cleaner system of claim 34, further comprising a pulse cleaning apparatus coupled to the housing proximate the clean air outlet, and wherein the inner filter is positioned closer to the clean air outlet than the pulse cleaning apparatus.

36. An air cleaner system comprising: a housing comprising a dirty air inlet and a clean air outlet; an inner filter located in the housing, the inner filter sealed about the clean air outlet such that dirty air entering the housing through the dirty air inlet must pass through the inner filter before entering the clean air outlet; an outer filter located in the housing, the outer filter comprising a first end sealed inside the housing proximate the clean air outlet and a second end located distal from the first end along a filter axis extending through the first end, the second end, and the clean air outlet, wherein dirty air entering the housing through the dirty air inlet must pass through the outer filter before passing through the inner filter, wherein the inner filter and the outer filter define an inter-filter volume therebetween; and a discharge outlet opening into the inter-filter volume, wherein pulsed gas entering the inter-filter volume through the discharge outlet moves along the filter axis through the inter-filter volume.

37. The air cleaner system of claim 36, further comprising a shield positioned in the inter-filter volume, the shield partially surrounding the inner filter along the circumference of the inner filter, and the shield and the outer filter defining a shieldouter filter volume within the inter-filter volume, wherein the discharge outlet opens into the shield-outer filter volume, wherein pulsed gas entering the shield-outer filter volume through the discharge outlet moves along the filter axis through the shieldouter filter volume.

38. A filter element, comprising: a filter media having a first end and a second end; a first, open end cap coupled to the first end of the filter media; a second end cap coupled to the second end of the filter media; and a baffle coupled to the first open end cap, the baffle having a portion projecting radially outward from the filter media at an angle greater than zero.