Self-cleaning air filter assembly

Abstract

A self-cleaning air filter assembly is provided and includes a filter housing defining an internal volume. An air filter element is disposed in the internal volume and separates the internal volume into upper and lower portions. The filter housing includes a canister port in fluid communication with the upper portion of the internal volume. The canister port is adapted for fluid connection with an evaporative emissions canister. The filter housing includes first and second ports in fluid communication with the lower portion of the internal volume. Contaminated air enters the lower portion of the internal volume via the first port and is cleaned by the air filter element, and contaminants collected by the air filter element are purged from the lower portion via the second port. A vehicle evaporative emissions control system including the air filter assembly and a method of cleaning an air filter assembly are also provided.

Description

SELF-CLEANING AIR FILTER ASSEMBLYCROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 523,966, filed June 29, 2023, the disclosure of which is incorporated by reference in its entirety.FIELD OF THE INVENTION

[0002] The disclosure generally relates to evaporative emissions control systems and, more specifically, to air filter assemblies for evaporative emissions control systems.BACKGROUND OF THE INVENTION

[0003] Evaporative loss of fuel vapor generated within fuel tanks of the fuel systems of motor vehicles powered by internal combustion engines is a potential contributor to atmospheric air pollution by hydrocarbons. Canister systems that employ adsorbents such as activated carbon to adsorb the fuel vapor emitted from the fuel systems are used to limit such evaporative emissions from the fuel tanks of gasoline-fueled automotive vehicles. A typical evaporative emissions canister includes a casing inside of which a gas passage is formed and filled with activated carbon as a fuel vapor adsorbent. Charge and purge ports for fuel vapor are communicated with one end of the gas passage, while an atmospheric port (vent port) is communicated with the other end of the gas passage, thus allowing for charging of the canister. During stoppage of the vehicle (e.g., when parked), fuel vapor generated from the fuel introduced during refueling and stored in the fuel tank is passed through the charge port into the canister and adsorbed by the adsorbent. During operation of the engine, atmospheric air is introduced through the atmospheric vent port to purge the fuel vapor in the canister by desorbing fuel vapor that was adsorbed in the adsorbent. The flow of air carries the purged fuel vapor to an intake system of the engine through the purge port so that the fuel vapor can be combusted within the engine, thus accomplishing a purging of the canister. By the desorption of fuel vapor during purging, the carbon adsorbent is regenerated and a fuel vapor adsorbing performance of the canister is revived, thereby allowing the adsorbent to repeatedly adsorb fuel vapor during periods of non-use of the engine.

[0004] The atmospheric vent port of the canister is typically connected to an air filter to allow for the removal of dirt, dust, debris, and other particulate matter from the vent air prior to its introduction into the canister. In some arrangements, the air filter is located in a filter housing having one port connected to the canister and another port connected to the vent. During purging, air is sucked through the vent-side port to the canister-side port, trapping the particulate matter in the filter before it can pass to the canister. However, the purgingoperation may only constitute approximately 10% of the vehicle engine run time, and outside of the purging operation, there is little to no air flow within the filter housing. Over time, the filter will become dirty and covered with particulate matter, which eventually may decrease the flowrate through the filter and the performance of the canister.

[0005] One such air filter is centrifugal dust collector that separates contaminants from the air by centrifugal force and accumulates the contaminants over time. However, the accumulation of contaminants such as dirt and dust can lead to contamination of the vent valve located between the centrifugal dust collector and the canister. Particularly, once the centrifugal dust collector becomes saturated with dust and other contaminants, these contaminants make their way from the centrifugal dust collector through the vent valve and into the canister. Contamination of the vent valve undesirably can lead to poor sealing of the valve (i.e., damage to the vent valve), and downstream contamination of the canister can lead to higher air flow restriction within the canister. Therefore, a need exists for an air filter for an evaporative emissions canister that is capable of self-cleaning to remove contaminants (dirt, dust, debris, etc.) collected by the air filter and / or that has better flow efficiency than the prior art.BRIEF SUMMARY

[0006] An improved, self-cleaning air filter assembly for a vehicle evaporative emissions control system is provided. The self-cleaning air filter assembly includes a filter housing defining an internal volume. An air filter element is disposed in the internal volume of the filter housing. The air filter element separates the internal volume into an upper portion and a lower portion. The filter housing includes a canister port in fluid communication with the upper portion of the internal volume. The canister port is adapted for fluid connection with an evaporative emissions canister. The filter housing includes a first port in fluid communication with the lower portion of the internal volume. The first port is adapted for fluid connection with an atmospheric vent. The filter housing includes a second port in fluid communication with the lower portion of the internal volume. The second port is adapted for fluid connection with an atmospheric vent. Contaminated air enters the lower portion of the internal volume of the filter housing via the first port and is cleaned by the air filter element, and contaminants collected by the air filter element are purged from the lower portion of the internal volume of the filter housing via the second port.

[0007] In specific embodiments, the second port is located at a bottom of the lower portion of the internal volume of the filter housing.

[0008] In specific embodiments, the second port is located at a position on the filter housing lower than a position at which the first port is located on the filter housing.

[0009] In specific embodiments, the first port is an air inlet, and the second port is an air outlet.

[0010] In specific embodiments, the first port is disposed at a position proximate the air filter element.

[0011] In specific embodiments, the second port is disposed at a position distal from the air filter element.

[0012] In specific embodiments, a check valve is connected to the first port. The check valve only allows air flow into the first port.

[0013] In specific embodiments, a check valve is connected to the second port. The check valve only allows air flow out of the second port.

[0014] In specific embodiments, the air filter element includes a top side and an opposite bottom side. The top side faces the upper portion of the internal volume of the filter housing. The bottom side faces the lower portion of the internal volume of the filter housing, and the bottom side impedes the flow of contaminants therethrough.

[0015] An evaporative emissions control system for a vehicle is also disclosed. The evaporative emissions control system includes the self-cleaning air filter assembly as described above. The system further includes an evaporative emissions canister having a charge port, a purge port, and a vent port. The vent port of the evaporative emissions canister is connected to and in fluid communication with the canister port of the air filter assembly. The first port of the filter housing is connected to and in fluid communication with an atmospheric vent. The second port of the filter housing is connected to and in fluid communication with an atmospheric vent.

[0016] In specific embodiments, the system includes a vent valve connected between the canister port of the air filter assembly and the vent port of the evaporative emissions canister.

[0017] In specific embodiments, (i) in a canister purge mode, air flows through the air filter element from the first port of the filter housing to the canister port of the filter housing, from the canister port to the vent port of the canister, and through the canister to the purge port of the canister, whereby contaminants in the air are collected in the lower portion of the internal volume of the filter housing by the air filter element; and (ii) in a self-cleaning mode, air flows through the canister from the charge port to the vent port of the canister, from the vent port to the canister port of the filter housing, and through the air filter element from the canister port of the filter housing to the second port of the filter housing, whereby the contaminants collected in the lower portion of the internal volume of the filter housing are expelled from the filter housing.

[0018] In particular embodiments, the second port of the filter housing is at a bottom of the filter housing such that gravity aids the expulsion of contaminants from the lower portion of the internal volume of the filter housing.

[0019] A method of self-cleaning an air filter assembly of a vehicle evaporative emissions control system is also provided. The method includes providing the self-cleaning air filter assembly as described above. The method further includes fluidly connecting the first port of the filter housing to an atmospheric vent. The method further includes fluidly connecting the second port of the filter housing to an atmospheric vent. The method further includes providing an evaporative emissions canister having a charge port, a purge port, and a vent port. The method further includes fluidly connecting the vent port of the evaporative emissions canister to the canister port of the air filter assembly. The method further includes flowing air from the charge port of the canister to the vent port of the canister, from the vent port of the canister to the canister port of the filter housing, and from the canister port of the filter housing through the air filter element and out the second port of the filter housing, whereby contaminants collected in the lower portion of the internal volume of the filter housing are expelled from the filter housing.

[0020] In specific embodiments, the method further includes connecting a vent valve between the canister port of the air filter assembly and the vent port of the evaporative emissions canister, and opening the vent valve to allow for flow of air between the canister port of the air filter assembly and the vent port of the evaporative emissions canister.DESCRIPTION OF THE DRAWINGS

[0021] Various advantages and aspects of this disclosure may be understood in view of the following detailed description when considered in connection with the accompanying drawing, wherein:

[0022] Figure 1 is a schematic view of an evaporative emissions control system in accordance with some embodiments of the disclosure.DETAILED DESCRIPTION OF THE INVENTION

[0023] A self-cleaning air filter assembly for an evaporative emissions control system is provided. Referring to Figure 1 , the evaporative emissions control system is illustrated and generally designated at 10. Certain features of the evaporative emissions control system 10 are functional, but can be implemented in different aesthetic configurations. References to upper, lower, top, bottom, and the like correspond to an upright disposition of the evaporative emissions control system 10 but are otherwise not intended to be limiting.

[0024] The evaporative emissions control system 10 generally includes an evaporative emissions canister 12 and the self-cleaning air filter assembly 14. The evaporative emissions canister 12 is illustrated as a fuel vapor storage canister for a fuel tank of a vehicle fuel system that pumps liquid fuel, by way of non-limiting example gasoline fuel, from the fueltank 16 to an internal combustion engine (not shown) that powers an automotive vehicle. The fuel vapor storage canister 12 traps fuel vapors that arise in the fuel tank during periods of non-use of the internal combustion engine due to, for example, daily variations in ambient temperatures and during refilling of the fuel tank. The canister 12 has at least one inlet and outlet in fluid communication with an internal volume of the canister. Particularly, the canister 12 has a charge port 18, a purge port 20, and a vent port 22. The charge port 18 and purge port 20 are disposed at one end of the internal volume of the canister 12, while the vent port 22 is disposed at an opposite end of a flow path through the internal volume, so that there may be fluid flow between the charge port 18 and the vent port 22 or between the vent port 22 and the purge port 20. The charge port 18 is connected to and in fluid communication with the vehicle fuel tank 16 via a conduit or similar. The purge port 20 is connected to and in fluid communication with a purge source (e.g. an air intake system) of the engine (not shown) via a conduit or similar. The vent port 22 is in fluid communication with the atmosphere for venting the canister 12 and for admission of purge air into the canister. More specifically, the vent port 22 is connected to the air filter assembly 14 which in turn is connected to an atmospheric vent. As described in greater detail below, the air filter assembly 14 filters ambient purge air that is then inhaled into the canister 12 during a purge operation. During non-use of the internal combustion engine when the engine is off (non- operational), fuel vapors generated in the fuel tank 16 travel through the charge port 18 and into the internal volume of the canister 12. The fuel vapors become trapped in the canister 12, and the remaining air exits the canister through the vent port 22. This flow is shown by the dashed-line arrows 24 in Figure 1. During certain periods of operation of the internal combustion engine when the engine is running, air is drawn into the canister 12 through the vent port 22, and the trapped fuel vapors are expelled from the canister 12 through the purge port 20 and into the air intake system of the internal combustion engine. This flow is shown by the dot-dashed-line arrows 26 in Figure 1 . It is therefore apparent that the charge port 18 is an inlet of the canister 12 and the purge port 20 is an outlet of the canister, while the vent port 22 may be an inlet or an outlet depending on the operational mode of the canister 12 (e.g., charging or purging) and the associated direction of flow.

[0025] With continued reference to Figure 1 , the air filter assembly 14 includes a filter housing 28 that defines an internal volume 30. An air filter element 32 is disposed in the internal volume 30 of the filter housing 28, and divides / separates the internal volume 30 into an upper portion 34 and a lower portion 36. The air filter element 32 has a top side 38 that faces the upper portion 34 of the filter housing 28 and an opposite bottom side 40 that faces the lower portion 36 of the filter housing 28. The air filter element 32 extends across the internal volume 30 of the filter housing 28 and partitions the internal volume between the upper and lower portions 34, 36. The air filter element 32 thus spans the entire cross-sectionof the filter housing 28 in a direction transverse to the longitudinal axis of the filter housing. The air filter element 32 may be a corrugated, pleated sheet of material (e.g., paper, fabric) and may be permanently installed within the filter housing 28 or may be included in a filter media cartridge that can be removed and replaced in the filter assembly 14. The bottom side 40 of the air filter element 32 impedes and / or prevents the flow and passage of contaminants through the air filter element so that air flows through the air filter element from the lower portion 36 of the internal volume 30 to the upper portion 34 but the contaminants do not, leaving clean air to exit the filter housing 28 as described below.

[0026] The filter housing 28 includes a canister port 42 that is directly connected to the upper portion 34 of the internal volume 30 of the filter housing 28 and that is connected to (fluidly connected) and in fluid communication with the vent port 22 of the canister 12. Charge air (flow arrows 24 in dashed lines) exiting the canister 12 via the vent port 22 enters into the air filter assembly 14 via the canister port 42, and clean purge air (flow arrows 26 in dash- dotted lines) exits the upper portion 34 of the internal volume 30 of the air filter assembly 14 through the same canister port 42. As such, the canister port 42 is both an inlet and an outlet, depending on the mode of the system 10. Optionally, a vent valve 44 may be disposed at one of or between the vent port 22 and the canister port 42. Opening and closing of the vent valve 44 may control flow of air between the canister 12 and the air filter assembly 14.

[0027] Advantageously, the filter housing 28 further includes two flow ports directly connected to the lower portion 36 of the internal volume 30 of the filter housing 28. Particularly, a first port 46 is connected to (fluidly connected) and in fluid communication with the lower portion 36. The first port 46 is also fluidly connected to an atmospheric vent 48 such that fresh air (which may be contaminated with airborne contaminants such as dust, dirt particles, debris, pollen, and the like) can be admitted into the lower portion 36 of the internal volume 30. As such, the first port 46 is an air inlet of the air filter assembly 14. The atmospheric vent 48 may be a passive ambient air passage that is open to the atmosphere. A check valve 50 may be connected to the first port 46 to provide for one-way flow of air into the lower portion 36 of the internal volume 30 via the first port 46, and to prevent flow of air out of the first port 46. The first port 46 may be disposed at a position proximate the air filter element 32 so that the air admitted into the lower portion 36 of the internal volume 30 is in close proximity to the air filter element 32 once it enters into the filter housing 28. Further, a second port 52 is also connected to (fluidly connected) and in fluid communication with the lower portion 36 of the internal volume 30. The second port 52 is fluidly connected to another atmospheric vent 54 such that contaminants (e.g., accumulated dust 56) halted and collected by the air filter element 32 can be purged / expelled from the lower portion 36 of the internal volume 30 of the filter housing 28 by a flow of air as described in more detail below. As such, the second port 52 is an air outlet of the air filter assembly 14. The atmospheric vent 54 maybe a passive ambient air passage that is open to the atmosphere. A check valve 58 may be connected to the second port 52 to provide for one-way flow of air out of the lower portion 36 of the internal volume 30 via the second port 52, and to prevent flow of air into the second port 52. The atmospheric vent 54 also may be a separate passage from the atmospheric vent 48, or the two may be connected at a position on an opposite side of the check valves 50, 58 relative to the filter housing 28. The second port 52 is located at a position on the filter housing 28 that is distal from the air filter element 32 and thus lower than a position at which the first port 46 is located. Hence, the second port 52 is spaced from the first port 46, and may either be opposite, across, and / or diagonal from the first port in relation to the lower portion 36 of the internal volume 30. For example, the second port 52 may be located at the bottom of the lower portion 36 of the internal volume 30 of the filter housing 28 so that contaminants collected by the air filter element 32 may be easily and efficiently purged from the filter housing 28, while the first port 46 may be located along a side of the filter housing 28.

[0028] During vehicle operation and rest, the evaporative emissions control system 10 switches between a charging / cleaning mode and a purging mode. As shown in Figure 1 by flow arrows 26 representing the direction of flow, fuel vapors trapped in the canister 12 are removed from the canister during the purging mode. The purge source provided by the vacuum suction of the air intake system of the vehicle’s engine draws air through the atmospheric vent 48 and into the filter housing 28 through the first port 46. As fresh air is drawn from the first port 46 through the filter housing 32 during a purge operation, the air filter element 32 traps contaminants (dust, dirt, and other particulate matter present in the ambient air) in the pleats of the air filter element, allowing only clean air to pass from the from the bottom side 40 of the filter 32 to the top side 38. Clean air is thus present in the upper portion 34 of the filter housing 28 and exits the filter housing so that the contaminants are not passed to the canister 12 but remain trapped in / on the bottom side 40 the air filter element 32 and / or are collected in the lower portion 36 of the filter housing 28. The clean air moves out of the filter housing 32 through the canister port 42 and to the vent port 22 of the canister 12 via the vent valve 44 (with the vent valve in an open disposition). As the clean air passes through the internal volume of the canister 12 from the vent port 22 to the purge port 20, fuel vapors trapped in the canister 12 are reabsorbed by the clean purge air and taken out of the canister via the purge port 20. The mixture of purge air and fuel vapors that leaves the canister 12 is sent to the vehicle’s engine where it is combusted. The purging mode may be toggled on and off by opening and closing of a valve (not shown) between the purge source and the canister 12. For example, the purging mode may be active, via the valve or other similar control, around 10% of the engine run time of the vehicle.

[0029] The charging / self-cleaning mode of the evaporative emissions control system 10 occurs when the vehicle’s engine is not running, and, for example, the vehicle is being refueled. Since the vehicle’s engine is off, the purge source (e.g., engine air intake system) is not operational. As shown in Figure 1 by flow arrows 24 representing the direction of flow, fuel dispensed from a gas pump through a fuel nozzle into the vehicle’s fuel tank 16 pushes vapors present in the fuel tank out of the tank and into the canister 12 at flow rates up to around 60 SLPM for approximately three to five minutes or as long as it takes to fill the vehicle’s fuel tank. As the fuel vapors pass through the canister 12, they become trapped by the adsorbent in the canister. Essentially only pure air exits the canister 12 through the vent port 22 and passes into the upper portion 34 of the filter housing 28 via the canister port 42. The up to 60 SLPM of air outflow from the canister 12 through the filter housing 28 dislodges some particulate material that is trapped in the air filter element 32 as the air passes from the upper portion 34 of the filter housing 28 to the lower portion 36. Vibration of the vehicle in which the canister 12 is installed may also enhance separation of the contaminants / particulate matter from the filter element 32. The dislodged material and other contaminants present in the lower portion 36 of the filter housing 28 are expelled from the air filter assembly 14 through the second port 52. The second port 52 is generally located at the bottom of the filter housing 28 so that gravity (gravitational force) can aid in the expulsion of the contaminants from the lower portion 36 during self-cleaning.

[0030] Due to the fact that the air filter assembly 14 prevents the passage of air contaminants and periodically self-cleans the collected contaminants from the assembly so that the assembly does not become saturated or over-saturated with contaminants, the air filter assembly avoids contaminants flowing downstream through the vent valve 44 and / or into the canister 12. Thus, the canister 12 has a constant flow restriction that is not raised by the presence of airborne contaminants. Further, since the air filter assembly 14 is capable of self-cleaning by utilizing the flow of air during a charging cycle of the canister 12, the air filter assembly 14 does not require outside intervention to be cleaned, and the air filter assembly maintains a high level of filtration efficiency that is not impeded by oversaturation of the air filter element 32, i.e. there is not any overaccumulation of contaminants in the air filter assembly 14. Furthermore, failure of the system to self-clean, if any failure at all, can be detected by a higher flow restriction in the air filter assembly, before any damage to the vent valve 44 or the canister 12.

[0031] In certain embodiments, the air filter assembly 14 and the evaporative emissions canister 12 may be combined together as a single, integral unit. For example, the canister port 42 of the air filter assembly 14 may be directly connected to the vent port 22 of the canister 12 (i.e., the canister port 42 and vent port 22 may be the same passage), thereby eliminating hoses, conduits, and / or connectors that would otherwise be necessary to connectthe canister port 42 and vent port 22. Such an arrangement also reduces the number of components required for the system, reducing the risk of assembly failure or leakages.

[0032] It is to be understood that the appended claims are not limited to express and particular compounds, compositions, or methods described in the detailed description, which may vary between particular embodiments which fall within the scope of the appended claims. With respect to any Markush groups relied upon herein for describing particular features or aspects of various embodiments, different, special, and / or unexpected results may be obtained from each member of the respective Markush group independent from all other Markush members. Each member of a Markush group may be relied upon individually and or in combination and provides adequate support for specific embodiments within the scope of the appended claims.

[0033] Further, any ranges and subranges relied upon in describing various embodiments of the present invention independently and collectively fall within the scope of the appended claims, and are understood to describe and contemplate all ranges including whole and / or fractional values therein, even if such values are not expressly written herein. One of skill in the art readily recognizes that the enumerated ranges and subranges sufficiently describe and enable various embodiments of the present invention, and such ranges and subranges may be further delineated into relevant halves, thirds, quarters, fifths, and so on. As just one example, a range “of from 0.1 to 0.9” may be further delineated into a lower third, i.e., from 0.1 to 0.3, a middle third, i.e., from 0.4 to 0.6, and an upper third, i.e., from 0.7 to 0.9, which individually and collectively are within the scope of the appended claims, and may be relied upon individually and / or collectively and provide adequate support for specific embodiments within the scope of the appended claims. In addition, with respect to the language which defines or modifies a range, such as “at least,” “greater than,” “less than,” “no more than,” and the like, it is to be understood that such language includes subranges and / or an upper or lower limit. As another example, a range of “at least 10” inherently includes a subrange of from at least 10 to 35, a subrange of from at least 10 to 25, a subrange of from 25 to 35, and so on, and each subrange may be relied upon individually and / or collectively and provides adequate support for specific embodiments within the scope of the appended claims. Finally, an individual number within a disclosed range may be relied upon and provides adequate support for specific embodiments within the scope of the appended claims. For example, a range “of from 1 to 9” includes various individual integers, such as 3, as well as individual numbers including a decimal point (or fraction), such as 4.1 , which may be relied upon and provide adequate support for specific embodiments within the scope of the appended claims.

Claims

CLAIMSWhat is claimed is:1 . A self-cleaning air filter assembly for a vehicle evaporative emissions control system, the air filter assembly comprising: a filter housing defining an internal volume; an air filter element disposed in the internal volume of the filter housing, the air filter element separating the internal volume into an upper portion and a lower portion; the filter housing including a canister port in fluid communication with the upper portion of the internal volume, the canister port being adapted for fluid connection with an evaporative emissions canister; the filter housing including a first port in fluid communication with the lower portion of the internal volume, the first port being adapted for fluid connection with an atmospheric vent; and the filter housing including a second port in fluid communication with the lower portion of the internal volume, the second port being adapted for fluid connection with an atmospheric vent; wherein contaminated air enters the lower portion of the internal volume of the filter housing via the first port and is cleaned by the air filter element, and contaminants collected by the air filter element are purged from the lower portion of the internal volume of the filter housing via the second port.

2. The self-cleaning air filter assembly of claim 1 , wherein the second port is located at a bottom of the lower portion of the internal volume of the filter housing.

3. The self-cleaning air filter assembly of claim 1 , wherein the second port is located at a position on the filter housing lower than a position at which the first port is located on the filter housing.

4. The self-cleaning air filter assembly of claim 1 , wherein the first port is an air inlet, and the second port is an air outlet.

5. The self-cleaning air filter assembly of claim 1 , wherein the first port is disposed at a position proximate the air filter element.

6. The self-cleaning air filter assembly of claim 1 , wherein the second port is disposed at a position distal from the air filter element.

7. The self-cleaning air filter assembly of claim 1 , including a check valve connected to the first port, the check valve only allowing air flow into the first port.

8. The self-cleaning air filter assembly of claim 1 , including a check valve connected to the second port, the check valve only allowing air flow out of the second port.

9. The self-cleaning air filter assembly of claim 1 , wherein the air filter element includes a top side and an opposite bottom side, the top side facing the upper portion of the internal volume of the filter housing, the bottom side facing the lower portion of the internal volume of the filter housing, and the bottom side impeding the flow of contaminants therethrough.

10. An evaporative emissions control system for a vehicle, the evaporative emissions control system comprising: the self-cleaning air filter assembly of claim 1 ; an evaporative emissions canister having a charge port, a purge port, and a vent port; the vent port of the evaporative emissions canister being connected to and in fluid communication with the canister port of the air filter assembly; the first port of the filter housing being connected to and in fluid communication with an atmospheric vent; and the second port of the filter housing being connected to and in fluid communication with an atmospheric vent.

11. The evaporative emissions control system of claim 10, including a vent valve connected between the canister port of the air filter assembly and the vent port of the evaporative emissions canister.

12. The evaporative emissions control system of claim 10, wherein:(i) in a canister purge mode, air flows through the air filter element from the first port of the filter housing to the canister port of the filter housing, from the canister port to the vent port of the canister, and through the canister to the purge port of the canister, whereby contaminants in the air are collected in the lower portion of the internal volume of the filter housing by the air filter element; and(ii) in a self-cleaning mode, air flows through the canister from the charge port to the vent port of the canister, from the vent port to the canister port of the filter housing, and through the air filter element from the canister port of the filter housing to the second port ofthe filter housing, whereby the contaminants collected in the lower portion of the internal volume of the filter housing are expelled from the filter housing.

13. The evaporative emissions control system of claim 12, wherein the second port of the filter housing is at a bottom of the filter housing such that gravity aids the expulsion of contaminants from the lower portion of the internal volume of the filter housing.

14. A method of self-cleaning an air filter assembly of a vehicle evaporative emissions control system, the method comprising: providing the self-cleaning air filter assembly of claim 1 ; fluidly connecting the first port of the filter housing to an atmospheric vent; fluidly connecting the second port of the filter housing to an atmospheric vent; providing an evaporative emissions canister having a charge port, a purge port, and a vent port; fluidly connecting the vent port of the evaporative emissions canister to the canister port of the air filter assembly; flowing air from the charge port of the canister to the vent port of the canister, from the vent port of the canister to the canister port of the filter housing, and from the canister port of the filter housing through the air filter element and out the second port of the filter housing, whereby contaminants collected in the lower portion of the internal volume of the filter housing are expelled from the filter housing.

15. The method of claim 14, further including: connecting a vent valve between the canister port of the air filter assembly and the vent port of the evaporative emissions canister; and opening the vent valve to allow for flow of air between the canister port of the air filter assembly and the vent port of the evaporative emissions canister.

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