Patent Grant
8245498
An apparatus is disclosed that can generally reduce crankcase emissions generated by an engine, including certain particulate matter, odor, and/or toxic exhaust gases, and by using for example various filtration, coalescing, and catalytic mechanisms.
Crankcase filtration assemblies are widely known and used in a number of engine applications, such as engine aerosol and oil filtration. For example, during the combustion process in a spark ignited or compression ignition engine, compression gases and other byproducts of combustion may enter into an engine's crankcase. This condition is called blow-by. At this time, gas pressure develops in the crankcase that is above atmospheric pressure. Due to the pressure increase, the blow-by gases are ventilated from the engine crankcase through openings, which are usually located in a valve cover assembly or upper engine block area. These blow-by gases contain various particulate matter, odor, and toxic exhaust gases as crankcase emissions. When the crankcase ventilates into the surrounding environment it is known as open crankcase ventilation (OCV). Over time, the blow-by flow rate increases. As a result, a blow-by gas stream may be carrying an increased amount of particulate matter, odor, and toxic exhaust gases.
In general, crankcase ventilation filtration typically occurs through a process known as separation, for example through a coalescer element and/or impactor element. Generally, separation structures are configured to separate condensates from the blow-by gas stream. When a coalescer element is employed, smaller particles may be separated from the blow-by gas stream and coalesce into larger particles to help remove such particulate matter from the blow-by gas stream. To aid in the coalescing process, crankcase filtration assemblies often employ a media structure that collects the smaller particles. In the example of an impactor element, a structure is employed that gets in the way of, or impacts the blow-by gas stream to trap more coarse particulate matter.
Beginning in 2007, crankcase emissions have been counted toward total engine emission levels. In certain situations, the crankcase emissions from older and less maintained engines were found to contribute the majority of the total unregulated toxic emissions. Current emission control products for crankcases employ separation structures that are designed to mainly reduce coarse particulate matter (PM) emissions. Such PM emissions typically are mechanically generated with a size range of larger than 0.5 micron. While it is important to control large PM emission in order to reduce the total PM mass emissions, studies show crankcases emit significant amounts of chemically and thermally generated ultra-fine PM (about<0.5 micron), gases, odor, and unregulated toxic species.
Improvements may be made upon existing emission control products where crankcase gases are emitted to the atmosphere, and particularly in products for open crankcase ventilation systems.
The following technical disclosure describes a unique apparatus that can generally reduce crankcase emissions generated by an engine, including particulate matter, odor, and/or toxic exhaust gases. The apparatus may be employed in an emissions system, for instance open crankcase ventilation emission systems of various engines, including compression ignition and spark ignited internal combustion engines, to reduce emissions in a blow-by gas stream.
The apparatus generally includes a separator that first removes particulate matter from the crankcase emissions and a treatment component downstream from the separator that reduces odor and removes certain toxic gases from the crankcase emissions. The apparatus may employ various separation mechanisms including filtration, coalescing, and impactor structures, and also may employ various catalytic mechanisms. Such separation and catalytic mechanisms may be employed in a number of configurations and arrangements to accomplish reducing and controlling such engine crankcase emissions.
In one embodiment, an apparatus for reducing crankcase emissions generated by an engine includes an inlet configured to receive crankcase emissions from the engine. A separator is operatively connected to the inlet. The separator is configured to remove particulate matter from the crankcase emissions. A treatment component is disposed downstream of the separator, and is configured to remove odor and toxic gases from the crankcase emissions. The apparatus further includes an outlet configured to release crankcase emissions that remain after processing by the separator and the treatment component.
In another embodiment, a method of reducing crankcase emissions generated by an engine includes removing particulate matter from the crankcase emissions. The step of removing the particulate matter includes receiving the crankcase emissions by a separator, removing the particulate matter from the crankcase emissions, and releasing the remaining crankcase emissions downstream to a treatment component. The treatment component removes odor and toxic gases from the remaining crankcase emissions. The step of removing odor and toxic gases includes receiving the remaining crankcase emissions by the treatment component, removing odor and gases from the remaining crankcase emissions, and releasing generally non-toxic emissions of the remaining crankcase emissions.
The following describes an improved apparatus that can generally reduce crankcase emissions generated by an engine, including for example particulate matter, odor, and/or toxic exhaust gases. One particular useful application for the apparatus described herein is to control and/or reduce particulate matter, gases, odor, and unregulated toxic emissions that may be contained in an engine crankcase blow-by gas stream, for example in open crankcase ventilation systems.
Regulatory organizations, such as the U.S. Environmental Protection Agency (EPA) and the California Air Resources Board, have identified a greater range of compounds which may pose considerable risk to the environment and public health. The EPA has developed a list of Mobile Source Air Toxics (MSAT) that contains a variety of compounds including fine particulate matter, aldehydes, and polycyclic organic matter (POM). Additionally, the Advanced Collaborative Emissions Study (ACES) program has identified more than 650 compounds which have been selected based upon established knowledge surrounding their toxicity and environmental impact.
Some examples of such MSAT compounds include but are not limited to, acetaldehyde, acrolein, arsenic compounds, benzene, 1,3-butadiene, chromium compounds, dioxins, furans, diesel particulate matter (DPM) and diesel organic gases (DEOG), ethylbenzene, formaldehyde, n-hexane, lead compounds, manganese compounds, mercury compounds, methyl tert-butyl ether (MTBE), naphthalene, nickel compounds, styrene, toluene, xylene, and polycyclic organic matter (POM). Some examples of POM include acenaphthene, chrysene, acenaphthylene, anthracene, dibenz (a,h) anthracene, fluoranthene, benz (a) anthracene, fluoranthene, fluorene, benzo (a) pyrene, indeno (1,2,3-cd) pyrene, benzo (b) fluoranthene, naphthalene, benzo (ghi) perylene, phenanthrene, benzo (k) fluoranthene, and pyrene. These compounds among others have been known to be toxic and to impact the environment.
The apparatus described herein may be employed in an emissions system, for instance in open crankcase ventilation systems of various engines, such as compression ignition and spark ignited internal combustion engines. The apparatus generally includes a separator that first removes particulate matter from the crankcase emissions, and includes a treatment component downstream from the separator that then reduces odor and removes certain toxic gases from the crankcase emissions. In the following exemplary embodiments, various separation mechanisms may be employed, including filters, coalescers, and impactors, and various catalytic mechanisms also may be employed. Such mechanisms may be employed in a number of configurations and arrangements to accomplish reducing such crankcase emissions.
In one embodiment, the separator 16 may be structured and arranged as a coalescing element, such as may be known in the art. A suitable coalescing element may have a structure that allows smaller particulate matter to be collected, so that larger particles may then form and be trapped therein. Generally, the separator 16 may be any suitable filter structure or flow through material that can capture and remove particulate matter from the crankcase emissions. As one example, the separator 16 may be a separator used in a crankcase ventilation filtration assembly as may be known in the art for receiving crankcase emissions and filtering out particulate matter, such as oil mist and condensates. High efficiency separators (i.e. coalescer) have been known to reduce particulate matter that may be present in a blow-by gas stream by as much as 70%, and even as high as 95%.
In some embodiments, the separator 16 includes a certain media construction, such as a pleated or non-pleated filter or may be a foam based material such as polyurethane foam. The media may be configured such that, when the crankcase emissions enter inlet 12 and flow through the separator 16, coalescing of various particulate matter may take place within the media. It will be appreciated that the media is constructed to produce optimum results for coalescing the particulate matter at a high efficiency. It will be appreciated that the media of the separator 16 may be arranged and configured using various implementations such as may be known in the art of crankcase ventilation filtration, and its structure is not limited as long as the separation function can be accomplished.
In some examples, the coalescer element includes a filter media constructed of a gradient fiber structure that includes multiple fibers such as may be known in the art. The gradient fiber structure may be configured as multiple layers, where the coalescer includes fibers with a fineness that increases downstream from a side proximate the inlet 12 toward the side distal from the inlet 12.
Other examples of structures for coalescer elements can be found in U.S. Patent Application Publication No. US 2007-0062886 A1, which describes filter media coalescers and which is herewith incorporated by reference in its entirety. It will be appreciated that coalescers are well known in the art for coalescing and separating a medium having two immiscible phases, namely a continuous phase (i.e. blow-by gases that flow through) and a dispersed phase (particulate matter that is separated).
It will be appreciated that the coalescer element may be arranged and configured using other implementations as may be known in the art. Such other implementations may include, but are not limited to, wire mesh, screens, filters, or any other suitable coalescing structures. One of skill in the art will appreciate that the separator 16 is not limited to any particular structure or configuration, and will appreciate that various coalescing and impactor constructions and configurations may be employed for accomplishing the separating function.
As shown in
Adsorption is well known as a process that occurs when a gas or liquid solute accumulates on the surface of a solid or a liquid (adsorbent), forming a molecular or atomic film (the adsorbate). Similar to surface tension, adsorption is a consequence of surface energy. In a bulk material, for example, all the bonding requirements (be they ionic, covalent or metallic) of the constituent atoms of the material are filled. Atoms on the (clean) surface, however, can experience a bond deficiency, because they are not wholly surrounded by other atoms. Thus, it is energetically favorable for them to bond with (adsorb) other material, where the exact nature of the bonding and material adsorbed depends on the details of the species involved, but the adsorbed material is generally classified as exhibiting physisorption or chemisorption. Adsorption is indicative in most natural physical, biological, and chemical systems, and is widely used in industrial applications. As some examples, adsorption, ion exchange, and chromatography are sorption processes in which certain adsorptives are selectively transferred from the fluid phase to the surface of insoluble, rigid particles suspended in a vessel or packed in a column. In one desired application, adsorption can be used to control odor, non-polar substances, and organics including PAHs and particularly in engine exhaust aftertreatment systems.
Some common industrial adsorbents are activated carbon, silica gel, alumina, and zeolites, because they present enormous surface areas per unit weight. Activated carbon is produced by roasting organic material to decompose it to granules of carbon (i.e. coconut shell, wood, and bone are common sources). Silica gel is a matrix of hydrated silicon dioxide. Alumina is mined or precipitated aluminum oxide and hydroxide. Although activated carbon is a magnificent material for adsorption, its black color persists and adds a grey tinge if even trace amounts are left after treatment; however, filter materials with fine pores have been known to remove carbon quite well.
The adsorbents are used usually in the form of spherical pellets, rods, moldings or monoliths with hydrodynamic diameter between 0.5 and 10 mm. Preferably, the adsorbents have high abrasion resistance, high thermal stability and small micropore diameter, which results in higher exposed surface area and hence high capacity of adsorption. Adsorbents preferably have a distinct macropore structure which enables fast transport of the gaseous vapors. Many industrial adsorbents fall into one of three classes:
By way of further background, a surface already heavily contaminated by adsorbates is not likely to have much capacity for additional binding. Freshly prepared activated carbon has a clean surface. For example, charcoal made from roasting wood differs from activated carbon in that its surface is contaminated by other products, but further heating will drive off these compounds to produce a surface with high adsorptive capacity. Although the carbon atoms and linked carbons are most important for adsorption, the mineral structure contributes to shape and to mechanical strength. Spent activated carbon can be regenerated by roasting, but thermal expansion and contraction eventually disintegrate the structure so some carbon is lost or oxidized.
In aftertreatment systems as described herein, the adsorbent material(s) can be contained in adsorber filters or canisters, such as carbon canisters which are well known. Such filters or canisters are flow through devices that carry out the adsorption function in aftertreatment systems.
Turning specifically back to the treatment component 18, the treatment component 18 in some embodiments may be an activated charcoal or activated carbon filter or canister. It will be appreciated that the treatment component also may include filter media such as a pleated, non-pleated, or bag based material as may be known in the adsorption filter art. In other embodiments, the treatment component 18 may be constructed as a non-pleated melt-blown polymer material. The filter or canister structure of the treatment component is meant to be non-limiting and may employ any filter and/or flow through structure so as to carry out the adsorption function as desired for a particular application.
In other embodiments, the adsorption material employed for the treatment component 18 may be silicon or a zeolite based flow through catalyst. For instance, surfaces of a filter or flow through structure for air may be loaded with an adsorption material (i.e. charcoal or activated carbon) to allow for adsorption of odorous materials (i.e. ammonia NH3) and/or exhaust gases to occur on the treatment component. In some embodiments, the adsorption material is activated charcoal or silicon material. In some embodiments, the adsorption material may be nano-sized material disposed on a front face or upstream side of the treatment component 18 or disposed within the media of the treatment component 18.
In the example where charcoal is employed, the odorous material and/or exhaust gases (adsorbent) may bind with the charcoal, so that a molecular or atomic film (adsorbate) may form on surfaces of the filter or flow through structure. In such a configuration, odorous material and exhaust gases may be removed from the crankcase emissions.
It will be appreciated that various amounts of the adsorption material may be employed, and that one of skill in the art would recognize a suitable or optimum amount of the adsorption material to be used for a desired application. For further reference, U.S. Pat. Nos. 6,735,940, 6,745,560 and 6,820,414, which are incorporated herewith by reference in their entirety, describe some particular implementations of adsorbers and catalytic soot filters in aftertreatment systems and some general principles of the use of adsorption in such applications. As yet for further reference, U.S. Pat. No. 6,701,902 also generally describes activated carbon canisters, which is incorporated herewith by reference in its entirety.
After processing by the separator 16 and treatment component 18 has taken place, the remaining crankcase emissions may be released from the outlet 14 (see arrow), such as a vent hose. It also will be appreciated that the adsorption materials employed, such as activated charcoal and silicon, may be replaced or regenerated regularly. Certain maintenance intervals, such as an oil change, may be a good estimate period for when the adsorption material of an adsorption filter should be replaced or regenerated.
Regarding both the separator and treatment component, one of skill in the art will appreciate that the filter structures that may be employed for the separator and treatment component, may be constructed as replaceable components as may be known in the art.
As shown in
In one embodiment, the treatment component 28 is disposed on an inner surface of the outlet 24. In some examples, the outlet 24 is structured and arranged as a tube, where the flow-through oxidation catalyst is incorporated therein.
In one embodiment, the impactor element 31 is configured to allow flow through of the crankcase emissions and to provide an impact surface for the particulate matter entering the apparatus 30. For example, a suitable structure for an impactor element is one that can “get in the way of” or impact the flow of the crankcase emissions. Such a structure allows the impactor element 31 to first separate relatively coarse, mechanically generated particulate matter from the crankcase emissions before the remaining crankcase emissions continue flowing through the apparatus 30 to the separator 36 and the treatment component 34. Such a configuration may help increase capacity and durability of the apparatus 30.
As the blow-by gas stream enters the inlet 32, the impactor element 31 provides an impact surface for the blow-by fluids, and provides a surface for causing a change in their flow direction. As a result of such a change in flow direction, the impactor element 31 causes can cause coarse particulate matter to be separated from the blow-by gas stream, and allow remaining crankcase emissions to flow toward the separator 36 and treatment component. Some examples of a structure for an impactor element, which are well known, can be found in U.S. Pat. No. 7,238,216 which describes an inertial gas-liquid impactor for removing particles from a liquid gas stream, and which is herewith incorporated by reference in its entirety.
One of skill in the art will appreciate that the impactor element 31 is not limited to any particular structure or configuration, and will appreciate that various constructions and configurations may be employed for accomplishing the separating function desired.
In operation, the impactor element 31 first removes relatively coarse particulate matter, followed by removal of relatively fine and ultra-fine particulate matter and particle phase unregulated species by the separator 36, and then followed by removal of odorous material and certain gases by the treatment component 38 (i.e. catalyst-coated outlet, catalyst-coated blow-by tubes, or catalysts-coated flow-through monolith substrates). Such a configuration provides additional serial filtration of coarse particulate matter (impactor element), more fine and ultra-fine particulate matter (separator), and odorous and/or toxic gases (treatment component).
Regarding the catalyst for the treatment component in the embodiments of
It will be appreciated that, in any embodiment employing the catalyst wash coating, various amounts of the catalyst wash coat may be employed. As in a typical DOC, one of skill in the art would recognize a suitable or optimum amount, concentration, and/or density of which the catalyst wash coat should be applied depending on the particular use and application.
In operation, the apparatus 40 provides an impactor element 41 that first removes relatively coarse particulate matter, followed by removal of relatively fine and ultra-fine particulate matter and particle phase unregulated species by the separator 46, and then followed by removal of odorous material and certain gases by the treatment component 48 (i.e. charcoal filter).
Differently from the previous embodiments, apparatus 50 includes a treatment component 58 disposed directly adjacent the separator 56. As with the previously described treatment components, treatment component 58 is configured to remove odor and exhaust gases from the crankcase emissions. In some examples, the treatment component 58 may be any suitable filter structure or flow through material disposed directly adjacent to the separator 56. In some embodiments, the treatment component 58 may be a separate and distinct structure that is positioned adjacent to the separator 56. In some instances, the treatment component 58 may be meltblown polymer material and connected to the separator 56. In other embodiments, the treatment component 58 is another layer of media formed on the separator 56. For example, the separator 56 is constructed and arranged of a multi-layer flow through element, where an adsorption material (i.e. charcoal or activated carbon material) is embedded in one of the downstream layers of the media of the separator 56. In such a configuration, odorous material and exhaust gases may be treated and/or removed.
As previously described, the treatment component 58 may be a filter or flow through media structure including an adsorption material (i.e. charcoal or activated carbon material) loaded on the media structure. By loaded, the adsorption material may be disposed on the surface of the media, embedded within the media, or otherwise put on the media. For example, surfaces of a filter or flow through structure may be loaded with adsorption material to allow for adsorption of odorous materials (i.e. ammonia NH3) and/or exhaust gases to occur on the treatment component. As described, the adsorption material in some embodiments is a charcoal/silicon material or otherwise is an activated carbon material. The odorous material and/or exhaust gases (adsorbent) may bind with the adsorption material, so that a molecular or atomic film (adsorbate) may form on surfaces of the filter or flow through structure. In such a configuration, odorous material and exhaust gases may be removed from the crankcase emissions.
In operation, the apparatus 50 may provide an impactor element 51 that first removes relatively coarse particulate matter, followed by removal of relatively fine and ultra-fine particulate matter and particle phase unregulated species by the separator 56, and then followed by removal of odorous material and certain gases by the treatment component 58 (i.e. charcoal filter disposed directly adjacent of the separator or as another layer of the separator).
While the embodiments illustrated in the figures show each apparatus with one separator and one treatment component (and with or without an impactor element), it will be appreciated that more than one separator and/or one or more treatment component may be employed as desired and/or necessary. For example, an apparatus may employ both a catalytic wash coat and a charcoal filter if such an implementation of a treatment component is desired and/or necessary.
The apparatus for reducing/controlling crankcase emissions can help engines comply with regulations for controlling particulate matter and gaseous emissions originating from a crankcase blow-by gas stream. The embodiments described herein provide an apparatus that can control odor from the crankcase blow-by gas stream, and may also reduce unregulated toxic emissions. The embodiments of an apparatus described herein may be employed in an emissions system of various engines, such as compression ignition and spark ignited internal combustion engines. More particularly, the apparatus described herein may be used in various open crankcase ventilation systems and their subsystems where removing certain emissions is desired and/or needed.
The apparatuses and methods described herein can reduce crankcase emissions as high as at least 70% efficiency in terms of reducing particulate matter and as high as at least 60% efficiency for reducing toxic odors and gas (i.e. hydrocarbon). Generally, apparatus designs with separators can have high efficiency in removing particulate matter at least as high as or greater than 70%. Likewise, apparatus designs with adsorption materials can have high efficiency in removing toxic odors and gases of at least as high as or greater 60%, and designs with oxidation catalysts can have high efficiency in removing toxic hydrocarbons at least as high as or greater than 60%.
The inventive concepts disclosed herein may be embodied in other forms without departing from the spirit or novel characteristics thereof. The embodiments disclosed in this application are to be considered in all respects as illustrative and not limiting. The scope of the invention is indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.
| Number | Name | Date | Kind |
|---|---|---|---|
| 6143049 | Gieseke et al. | Nov 2000 | A |
| 6161529 | Burgess | Dec 2000 | A |
| 6412477 | Saruwatari et al. | Jul 2002 | B2 |
| 6701902 | Koyama et al. | Mar 2004 | B2 |
| 6735940 | Stroia et al. | May 2004 | B2 |
| 6745560 | Stroia et al. | Jun 2004 | B2 |
| 6820414 | Stroia et al. | Nov 2004 | B2 |
| 6907869 | Burgess et al. | Jun 2005 | B2 |
| 7238216 | Malgorn et al. | Jul 2007 | B2 |
| 20060254426 | Liu et al. | Nov 2006 | A1 |
| 20070062886 | Rego et al. | Mar 2007 | A1 |
| 20070107396 | Zuberi | May 2007 | A1 |
| 20070144348 | Gieseke et al. | Jun 2007 | A1 |
| 20070160510 | Schultz et al. | Jul 2007 | A1 |
| 20080035103 | Barris et al. | Feb 2008 | A1 |
| 20080245037 | Rogers et al. | Oct 2008 | A1 |
| Number | Date | Country |
|---|---|---|
| 2006-152890 | Jun 2006 | JP |
| WO 2004045743 | Jun 2004 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 20090313977 A1 | Dec 2009 | US |
