US20150128918A1

US20150128918A1 - Blow-by filter for internal combustion engines

Info

Publication number: US20150128918A1
Application number: US14/077,454
Authority: US
Inventors: Serge V. Monros
Original assignee: Individual
Current assignee: Individual
Priority date: 2013-11-12
Filing date: 2013-11-12
Publication date: 2015-05-14
Also published as: WO2015073058A1

Abstract

An open-ended canister includes a blow-by intake port for receiving contaminated blow-by gases and a fuel vapor exhaust port for venting purified blow-by gases. The open end of the canister is fitted with a removable cover that can be clamped in place. The removable cover includes an oil drainage port for draining cleansed engine oil back to the crankcase of the engine. The canister contains a filtering assembly made of multiple layers of metal mesh of differing gauges. The metal mesh may include one type of metal or several types of metal.

Description

FIELD OF THE INVENTION

The present invention generally relates to a filter for controlling pollution produced by an internal combustion engine. More particularly, the present invention relates to a filter for blow-by gases created within the crankcase of an internal combustion engine.

BACKGROUND OF THE INVENTION

The basic operation of standard internal combustion engines vary somewhat based on the type of combustion process, the quantity of cylinders and the desired use/functionality. For instance, in a traditional two-stroke engine, oil is pre-mixed with fuel and air before entry into the crankcase. The oil/fuel/air mixture is drawn into the crankcase by a vacuum created by the piston during intake. The oil/fuel mixture provides lubrication for the cylinder walls, crankshaft and connecting rode bearing in the crankcase. In a standard gasoline engine, the fuel is then compressed in the combustion chamber and ignited by a spark plug that causes the fuel to burn. There are no spark plugs in a diesel engine, so combustion in a diesel engine occurs only as a result of the heat and compression in the combustion chamber. The piston is then pushed downwardly and the exhaust fumes are allowed to exit the cylinder when the piston exposes the fuel vapor exhaust port. The movement of the piston pressurizes the remaining oil/fuel in the crankcase and allows additional fresh oil/fuel/air to rush into the cylinder, thereby simultaneously pushing the remaining exhaust out the fuel vapor exhaust port. Momentum drives the piston back into the compression stroke as the process repeats itself.
Alternatively, in a four-stroke engine, oil lubrication of the crankshaft and connecting rod bearing is separate from the fuel/air mixture. Here, the crankcase is filled mainly with air and oil. It is the intake manifold that receives and mixes fuel and air from separate sources. The fuel/air mixture in the intake manifold is drawn into the combustion chamber where it is ignited by the spark plugs (in a standard gasoline engine) and burned. In a diesel engine, the fuel/air mixture is ignited by heat and pressure in the combustion chamber. The combustion chamber is largely sealed off from the crankcase by a set of piston rings that are disposed around an outer diameter of the pistons within the piston cylinder. This keeps the oil in the crankcase rather than allowing it to burn as part of the combustion stroke, as in a two-stroke engine. Unfortunately, the piston rings are unable to completely seal off the piston cylinder. Consequently, crankcase oil intended to lubricate the cylinder is, instead, drawn into the combustion chamber and burned during the combustion process. Additionally, combustion waste gases comprising unburned fuel and exhaust gases in the cylinder simultaneously pass the piston rings and enter the crankcase. The waste gas entering the crankcase is commonly called “blow-by” or “blow-by gas”.
Blow-by gases mainly consist of contaminants such as hydrocarbons (unburned fuel), carbon dioxide or water vapor, all of which are harmful to the engine crankcase. The quantity of blow-by gas in the crankcase can be several times that of the concentration of hydrocarbons in the intake manifold. Simply venting these gases to the atmosphere increases air pollution. Although trapping the blow-by gases in the crankcase allows the contaminants to condense out of the air and accumulate therein over time. Condensed contaminants form corrosive acids and sludge in the interior of the crankcase that dilutes the lubricating oil. This decreases the ability of the oil to lubricate the cylinder and the crankshaft. Degraded oil that fails to properly lubricate the crankcase components (e.g. the crankshaft and connecting rods) can be a factor in poor engine performance. Inadequate crankcase lubrication contributes to unnecessary wear on the piston rings which simultaneously reduces the quality of the seal between the combustion chamber and the crankcase. As the engine ages, the gaps between the piston rings and cylinder walls increase resulting in larger quantities of blow-by gases entering the crankcase. Too much blow-by gases entering the crankcase can cause power loss and even engine failure. Moreover, condensed water in the blow-by gases can cause engine parts to rust.
These issues are especially problematic in diesel engines. Diesel engines burn diesel fuel which is much more oily and heavy than gasoline. As it burns, diesel fuel produces carcinogens, particulate matter (soot), and NOx (nitrogen contaminants). This is why most diesel engines are associated with the image of a big rig truck belching black smog from its exhaust pipes. Similarly, the blow-by gas produced in the crankcase of a diesel engine is much more oily and heavy than gasoline blow-by gas. Hence, crankcase ventilation systems for diesel engines were developed to remedy the existence of blow-by gases in the crankcase. In general, crankcase ventilation systems expel blow-by gases out of a positive crankcase ventilation (PCV) valve and into the intake manifold to be re-burned. In a diesel engine, the diesel blow-by gases are much heavier and oilier than in a gasoline engine. As such, the diesel blow-by gases must be filtered before they can be recycled through the intake manifold.
PCV valves recirculate (i.e. vent) blow-by gases from the crankcase back into the intake manifold to be burned again with a fresh supply of air/fuel during combustion. This is particularly desirable as the harmful blow-by gases are not simply vented to the atmosphere. A crankcase ventilation system should also be designed to limit, or ideally eliminate, blow-by gas in the crankcase to keep the crankcase as clean as possible. Early PCV valve comprised simple one-way check valves. These PCV valves relied solely on pressure differentials between the crankcase and intake manifold to function correctly. When a piston travels downward during intake, the air pressure in the intake manifold becomes lower than the surrounding ambient atmosphere. This result is commonly called “engine vacuum”. The vacuum draws air toward the intake manifold. Accordingly, air is capable of being drawn from the crankcase and into the intake manifold through a PCV valve that provides a conduit therebetween. The PCV valve basically opens a one-way path for blow-by gases to vent from the crankcase back into the intake manifold. In the event the pressure difference changes (i.e. the pressure in the intake manifold becomes relatively higher than the pressure in the crankcase), the PCV valve closes and prevents gases from exiting the intake manifold and entering the crankcase. Hence, the PCV valve is a “positive” crankcase ventilation system, wherein gases are only allowed to flow in one direction—out from the crankcase and into the intake manifold. The one-way check valve is basically an all-or-nothing valve. That is, the valve is completely open during periods when the pressure in the intake manifold is relatively less than the pressure in the crankcase. Alternatively, the valve is completely closed when the pressure in the crankcase is relatively lower than the pressure in the intake manifold. One-way check valve-based PCV valves are unable to account for changes in the quantity of blow-by gases that exist in the crankcase at any given time. The quantity of blow-by gases in the crankcase varies under different driving conditions and by engine make and model.
PCV valve designs have been improved over the basic one-way check valve and can better regulate the quantity of blow-by gases vented from the crankcase to the intake manifold. One PCV valve design uses a spring to position an internal restrictor, such as a cone or disk, relative to a vent through which the blow-by gases flow from the crankcase to the intake manifold. The internal restrictor is positioned proximate to the vent at a distance proportionate to the level of engine vacuum relative to spring tension. The purpose of the spring is to respond to vacuum pressure variations between the crankcase and intake manifold. This design is intended to improve on the all-or-nothing one-way check valve. For example, at idle, engine vacuum is high. The spring-biased restrictor is set to vent a large quantity of blow-by gases in view of the large pressure differential, even though the engine is producing a relatively small quantity of blow-by gases. The spring positions the internal restrictor to substantially allow air flow from the crankcase to the intake manifold. During acceleration, the engine vacuum decreases due to an increase in engine load. Consequently, the spring is able to push the internal restrictor back down to reduce the air flow from the crankcase to the intake manifold, even though the engine is producing more blow-by gases. Vacuum pressure then increases as the acceleration decreases (i.e. engine load decreases) as the vehicle moves toward a constant cruising speed. Again, the spring draws the internal restrictor back away from the vent to a position that substantially allows air flow from the crankcase to the intake manifold. In this situation, it is desirable to increase air flow from the crankcase to the intake manifold, based on the pressure differential, because the engine creates more blow-by gases at cruising speeds due to higher engine RPMs. Hence, such an improved PCV valve that solely relies on engine vacuum and the spring-biased restrictor does not optimize the ventilation of blow-by gases from the crankcase to the intake manifold, especially in situations where the vehicle is constantly changing speeds (e.g. city driving or stop-and-go highway traffic).
One key aspect of crankcase ventilation is that engine vacuum varies as a function of engine load, rather than engine speed, and the quantity of blow-by gases varies, in part, as a function of engine speed, rather than engine load. For example, engine vacuum is higher when engine speeds remain relatively constant (e.g. idling or driving at a constant velocity). Thus, the amount of engine vacuum present when an engine is idling (perhaps 90° rotations per minute (rpm)) is essentially the same as the amount of vacuum present when the engine is cruising at a constant speed on a highway (for example between 2,500 to 2,800 rpm). The rate at which blow-by gases are produced is much higher at 2,500 rpm than at 900 rpm. But, a spring-based PCV valve is unable to account for the difference in blow-by gas production between 2,500 rpm and 900 rpm because the spring-based PCV valve experiences a similar pressure differential between the intake manifold and the crank case at these different engine speeds. The spring is only responsive to changes in air pressure, which is a function of engine load rather than engine speed. Engine load typically increases when accelerating or when climbing a hill, for example. As the vehicle accelerates blow-by gas production increases, but the engine vacuum decreases due to the increased engine load. Thus, the spring-based PCV valve may vent an inadequate quantity of blow-by gases from the crankcase during acceleration. This problem is further complicated when the PCV valve becomes gummed up with particulate matter in the blow-by gas and is no longer capable of opening and closing normally.
Regularly changing the lubricating oil in the crankcase can help keep the PCV valve from seizing up with sludge, but even regular oil changes may not help if the gasoline or diesel fuel used in the engine is contaminated, thereby producing contaminated blow-by gasses. A plugged PCV valve will eventually damage the engine.
Accordingly, there is a need for an extra filtration step to ensure the blow-by gas entering the PCV valve is relatively free of oil and other contaminants. The present invention fulfills these needs and provides other related advantages.

SUMMARY OF THE INVENTION

The present invention comprises a blow-by filter for an internal combustion engine. The blow-by filter includes a canister with a closed top portion and an open bottom portion. The closed top portion includes a blow-by intake port and a fuel vapor exhaust port therein. The bottom portion includes a removable cover that is configured to cover the open bottom portion of the canister. The removable cover is fitted with an oil drainage port. The canister contains a filtering assembly. The filtering assembly is made from multiple layers of metal mesh of differing gauges.
The multiple layers of metal mesh in the filtering assembly are made of a type of metal including steel, stainless steel, aluminum, copper, brass, or bronze. The multiple layers of metal mesh of differing gauges may be all one type of metal, or may be a combination of two or more types of metal. The filtering assembly is contained in the canister by the removable cover in the bottom portion of the canister. The removable cover is held in place with clamps between the open bottom portion of the canister and the removable cover. A gasket may be placed in between the removable cover and the open bottom portion to provide an air-tight seal therein. The gasket may be made of a compressible material that is heat resistant and impermeable to both air and liquid.
Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings illustrate the invention. In such drawings:

FIG. 1 is a schematic illustration of a blow-by filter for a car engine;

FIG. 2 is a schematic illustration showing the general functionality of the blow-by filter with a PCV valve and a combustion-based car engine;

FIG. 3 is an elevational view of the blow-by filter, illustrating the placement of the intake, exhaust, and oil drainage ports;

FIG. 4 is an enlarged side view of the area indicated by circle 4 of FIG. 3, illustrating the closed top portion of the canister of the blow-by filter;

FIG. 5 is an enlarged fragmented view taken from circle 5 of FIG. 3, illustrating the bottom portion of the canister of the blow-by filter;

FIG. 6 is a cut-away side view of the blow-by filter, illustrating the filtering assembly with its multiple layers of metal mesh of differing gauges; and

FIG. 7 is an exploded view of the bottom portion of the canister of the blow-by filter.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

As shown in the drawings for purposes of illustration, a blow-by filter for an internal combustion engine is referred to generally by the reference number 10. In FIG. 1, the blow-by filter 10 is preferably mounted under a hood 16 of an automobile 14, adjacent to an engine 12. The blow-by filter 10 is coupled to the engine 12 and receives blow-by gases from the engine 12. These gases are filtered by the blow-by filter 10, and purified gasoline vapors are re-burned by the engine 12, while purified engine oil drains back into the engine 12. This process is described in more detail below.
FIG. 2 is a schematic illustrating the operation of the blow-by filter 10 in conjunction with a PCV valve 18 in a car engine 12. As shown in FIG. 2, the blow-by filter 10 and PCV valve 18 are disposed between the crankcase 20, of an engine 12, and an intake manifold 22. In a diesel engine, the intake manifold 22 receives a mixture of fuel and air via a fuel line 28 and an air line 24. The fuel line 28 also provides fuel for direct injection into the combustion chamber 38. In a gasoline engine, the fuel line 28 does not directly inject fuel into the combustion chamber 38. Rather, the fuel line 28 is only connected to the intake manifold 22. An air filter 26 may be disposed between the air line 24 and the air intake line 32 to filter fresh air entering the intake manifold 22. The air in the intake manifold 22 is delivered to a piston cylinder 34 as a piston 36 descends downward within the cylinder 48 from the top dead center. As the piston 36 descends downward, a vacuum is created within a combustion chamber 38. Accordingly, an input camshaft 40 rotating at half the speed of the crankshaft 42 is designed to open an input valve 44 thereby subjecting the intake manifold 22 to the engine vacuum. Thus, air is drawn into the combustion chamber 38 from the intake manifold 22.
Once the piston 36 is at the bottom of the piston cylinder 34, the vacuum effect ends and air is no longer drawn into the combustion chamber 38 from the intake manifold 22. At this point, the piston 36 begins to move back up the piston cylinder 34, and the air in the combustion chamber 38 becomes compressed. Next, in a diesel engine, fuel is injected directly into the combustion chamber 38 from the fuel line 28. This injection is further aided by more compressed air from a compressed air line 30. The compressed air line 30 is not present in a gasoline engine. As the air and fuel in the combustion chamber 38 is compressed, it heats up until the fuel ignites and combustion occurs. In a gasoline engine, a spark plug (not shown) replaces the fuel line 28 and compressed air line 30 that feed into the combustion chamber 38. The spark plug provides the ignition for the fuel, which then combusts. This is the main difference between diesel and gasoline engines. A gasoline engine relies on spark plugs to provide fuel ignition, while a diesel engine needs only heat and compression.
The rapid expansion of the ignited fuel/air in the combustion chamber 38 causes depression of the piston 36 within the cylinder 34. After combustion, an exhaust camshaft 46 opens an exhaust valve 48 to allow escape of the combustion gases from the combustion chamber 38 out an exhaust line 50. Typically, during the combustion cycle, excess exhaust gases slip by a pair of piston rings 52 mounted in a head 54 of the piston 36. These “blow-by gases” enter the crankcase 20 as high pressure and temperature gases. Over time, harmful exhaust gases such as hydrocarbons, carbon monoxide, nitrous oxide and carbon dioxide can condense out from a gaseous state and coat the interior of the crankcase 20 and mix with the oil 56 that lubricates the mechanics within the crankcase 20. The PCV valve 18 is designed to recycle these blow-by gases from the crankcase 20 to be re-burned by the engine 12. This is accomplished by using the pressure differential between the crankcase 20 and the intake manifold 22. In operation, the blow-by gases exit the relatively higher pressure crankcase 22 through a vent 58 and travel through a vent line 60, the blow-by filter 10, the PCV valve 18, and then return to the engine via either the fuel line 28 or the blow-by line 62. The fuel line 28 receives fuel vapors that are more pure, while the less pure blow-by gases are vented from the crankcase 20 to the intake manifold 22 via the blow-by line 62. In a gasoline engine, the blow-by gases can only return via the blow-by line 62 as there is no direct fuel injection. This process may be digitally regulated by a micro controller (not shown).
The PCV valve 18 regulates the vacuum between the intake manifold 22 and the crankcase 20. The PCV valve 18 includes a one-way check valve (not shown) that opens to allow blow-by gases through the valve when the vacuum between the intake manifold 22 and the crankcase 20 is strong enough. With the one-way check valve open, blow-by gases pass through the PCV valve 18 to be recycled through the intake manifold 22. Once the vacuum pressure subsides, the one-way check valve closes preventing the blow-by gas from passing through the PCV valve 18. The one-way check valve can also be controlled by a micro controller for added fuel efficiency.
As stated above, blow-by gases are not pure fuel vapors. Rather, when the un-ignited fuel is pulled into the crankcase 20, past the piston rings 52, the fuel vapors mix with the oil 56 that lubricates the mechanics within the crankcase 20. Over time, harmful exhaust gases such as hydrocarbons, carbon monoxide, nitrous oxide and carbon dioxide can condense out from a gaseous state to mix with the oil 56 and the fuel vapors. Thus, the resulting blow-by gases contain harmful impurities making them unsuitable for re-burning in the engine. In a diesel engine, diesel fuel contains more oil than gasoline, so the blow-by gases are significantly oilier. Oily and sludgy blow-by gases are not only non-suitable for re-burn, they also tend to gum up the PCV valve 18 making it impossible for the blow-by gases to be recycled at all. Thus, a blow-by filter 10 is necessary to clean the impurities out of the blow-by gases before they enter the PCV valve 18. The blow-by filter 10 is also needed to return cleansed engine oil 56 back to the crankcase 20 for further use.
The blow-by filter 10 is particularly illustrated in FIGS. 3-7. In FIG. 3, the blow-by filter 10 is shown in a side view. The blow-by filter 10 includes a canister 64 with a closed top portion 70 and a bottom portion 72. The canister 64 can be made of metal, plastic, or any other material or composite that is suitable for use in a high temperature, high pressure task. The closed top portion 70 of the canister 64 includes a blow-by intake port 66 and a fuel vapor exhaust port 68. The blow-by intake port 66 receives blow-by gases from the crankcase 20 of the engine 12 and passes the blow-by gases into the interior of the canister 64. The fuel vapor exhaust port 68 vents purified blow-by gases from the interior of the canister 64 to the PCV valve 18 (see FIG. 2) to be returned to the engine 12. The closed top portion 70 of the canister 64 is not removable from the canister 64.
The bottom portion 72 of the canister 64 includes a removable cover 74 with clamps 76. The removable cover 74 includes an oil drainage port 78 that allows for purified oil 56 (see FIG. 2) to drain back to the crankcase 20 of the engine 12 (see FIG. 2). The blow-by intake port 66, fuel vapor exhaust port 68, and oil drainage port 78 are shown with various fittings in the preferred embodiment, but in other embodiments, these ports 66, 68, and 78 may include other fittings as necessary to create a proper connection with the appropriate engine parts. The blow-by intake port 66, fuel vapor exhaust port 68, and oil drainage port 78 may or may not be made of the same material as the canister 64, but any material used to make these ports 66, 68, and 78 must be heat and pressure resistant.
FIG. 4 is taken from circle 4 of FIG. 3 and shows the closed top portion 70 of the canister 64 in greater detail. The closed top portion 70 of the canister 64 may be molded as part of the canister 64, or may be permanently attached to the canister 64 via some means such as welding. Likewise, the blow-by intake port 66 and fuel vapor exhaust port 68 are permanently attached to the closed top portion 70 of the canister 64. FIG. 5 is taken from circle 5 of FIG. 3 and shows the bottom portion 72 of the canister 64 in greater detail. The bottom portion 72 features a removable cover 74 that is attached to the canister 64 with clamps 76. The removable cover 74 is configured to cover the open bottom portion 72 of the canister 64. Two clamps 76 are shown in the preferred embodiment, but more clamps 76 may be included if necessary. The removable cover 74 is fitted with an oil drainage port 78. The oil drainage port 78 allows for purified oil 56 (not shown) to drain back to the engine crankcase 20 via the oil return line 80 (see FIG. 2). The oil drainage port 78 may be offset from the center of the removable cover 74 in order to account for the angle of the blow-by filter 10 as it is mounted under the hood 16 of an automobile 14. The removable cover 74 allows for easy access to the interior of the canister 64. This makes for easy cleaning and replacement of the contents of the canister 64.
The blow-by filter 10 is shown in a cut-away side view in FIG. 6. Here, the filtering assembly 84 is shown in detail. The filtering assembly 84 comprises multiple layers of metal mesh 86 of differing gauges. These layers of metal mesh 86 are loaded into the canister 64 through the canister's open end 88. The layers of metal mesh 86 may be of the same type of metal, or may be of different types of metal. The types of metal that may be used include, but are not limited to: steel, stainless steel, aluminum, copper, brass, or bronze. In operation, unfiltered blow-by gases are received by the blow-by intake port 66 in the closed top portion 70 of the canister 64. The blow-by gases begin to circulate through the layers of metal mesh 86 in the canister 64. Different contaminants and impurities are trapped at each layer of metal mesh depending on the gauge of the mesh and type of the metal. Larger contaminants are filtered by larger gauges of metal mesh 86. Smaller contaminants and impurities are filtered by the finer gauges of metal mesh 86. Likewise, some impurities may be trapped by certain types of metal. As the blow-by gases work through the filtering assembly 84, contaminants and impurities are trapped leaving two main bi-products: cleansed engine oil 56, and purified fuel vapor. The cleansed engine oil 56 eventually collects in the bottom portion 72 of the canister 64 where it drains via the oil drainage port 78 back to the crankcase 20 of the engine 12. The purified fuel vapor is vented through the fuel vapor exhaust port 68 in the closed top portion 70 of the canister 64 to pass to the PCV valve 18 to be recycled through the intake manifold 22 of the engine 12. When the filtering assembly 84 requires periodic cleaning and maintenance, it can be removed from the canister by un-latching the clamps 76 and removing the lid 74 from the bottom portion 72 of the canister 64.
The open end 88 of the bottom portion 72 of the canister 64 is shown in FIG. 7, along with a gasket 90 and the removable cover 74. The gasket 90 fits between the open end 88 of the canister 64 and the removable cover 74. The gasket 90 is made of a compressible material that is heat resistant and impermeable to both air and liquid. Such a compressible material may be plastic, rubber, or some other material with these properties. The purpose of including the gasket 90 at this position is to create a seal between the canister 64 and the removable like 74 that prevents oil or other contaminants from leaking out. This may be essential because the contents of the canister 64 are under high pressure and temperatures. The gasket 90 may be removable for cleaning or replacement purposes.
Although a preferred embodiment of the invention has been described in detail for purposes of illustration, various modifications may be made to each without departing from the scope and spirit of the invention. Accordingly, the invention is not to be limited, except as by the appended claims.

Claims

What is claimed is:

1. A blow-by filter for an internal combustion engine, comprising:

a canister having a closed top portion and an open bottom portion;

a blow-by intake port and a fuel vapor exhaust port extending through the closed top portion of the canister;

a removable cover attached to the open bottom portion of the canister;

an oil drainage port extending through the removable cover; and

a filtering assembly disposed within the canister, the filtering assembly comprising multiple layers of metal mesh having differing gauges.

2. The blow-by filter of claim 1, wherein the multiple layers of metal mesh comprise steel, stainless steel, aluminum, copper, brass, or bronze.

3. The blow-by filter of claim 2, wherein the multiple layers of metal mesh having differing gauges comprise one type of metal.

4. The blow-by filter of any of claims 1-3, further comprising a gasket between the removable cover and the open bottom portion of the canister for sealing the open bottom portion of the canister.

5. The blow-by filter of claim 4, wherein the gasket comprises a compressible material that is heat resistant and impermeable to both air and liquid.

6. The blow-by filter of any of claims 1-3, further comprising clamps between the open bottom portion of the canister and the removable cover.

7. A blow-by filter for an internal combustion engine, comprising:

a canister having a closed top portion and an open bottom portion;

a removable cover attached to the open bottom portion and configured to cover and seal the open bottom portion;

a gasket between the removable cover and the open bottom portion of the canister configured to seal the open bottom portion of the canister;

clamps between the open bottom portion of the canister and the removable cover;

an oil drainage port extending through the removable cover; and

a filtering assembly disposed within the canister, the filtering assembly comprising multiple layers of a combination of types of metal mesh having differing gauges.

8. The blow-by filter of claim 7, wherein the canister is offset from the internal combustion engine.

9. The blow-by filter of claim 7, wherein the multiple layers of a combination of types of metal mesh comprise steel, stainless steel, aluminum, copper, brass, or bronze.

10. The blow-by filter of any of claims 7-9, wherein the multiple layers of a combination of types of metal mesh having differing gauges comprise a combination of types of metal.

11. The blow-by filter of claim 10, wherein the gasket comprises a compressible material that is heat resistant and impermeable to both air and liquid.