Module integrating mixer and particulate separator into a common housing and an engine breathing system having the module

One exemplary embodiment includes a product including a housing that has a mixer portion and first, second and third openings. The first opening is configured to receive at least a portion of exhaust gases produced by an internal combustion engine, and the second opening is configured to receive intake air. The mixer portion is in communication with the first and second openings to mix the exhaust gases and the intake air into a gas mixture. The third opening is in communication with the mixer portion to flow the gas mixture therethrough. The invention further includes a particulate separator disposed within the housing. The particulate separator is configured to remove particulates from the exhaust gases. The product may be included in a low-pressure EGR path and/or a high-pressure EGR path.

TECHNICAL FIELD

The disclosure generally relates to engine breathing systems, components of engine breathing systems, and methods of making and using the same.

BACKGROUND

Current and future emissions requirements for diesel and gasoline engines in Europe, US and most foreign markets will require engine concepts capable of achieving low NOxand low particulate matter emissions while at the same time meeting requirements for low-cost systems and packaging needs.

FIG. 1is a schematic illustration of a prior art diesel engine breathing system64using a single-stage turbo charger. Such a system64includes a low pressure exhaust gas recirculation (EGR) loop66, including a first EGR path7, a first EGR valve8, and a first cooler9.

The system64includes a high-pressure loop68having a second EGR path15, second EGR valve16and second EGR cooler17. Exhaust gas is generated by an engine1and exits through an exhaust gas manifold2. The exhaust gas from the exhaust gas manifold2can be directed in two directions.

In the first direction, the gas may flow through the high-pressure loop68and into the intake manifold14. To create enough EGR flow through the second EGR path15and second EGR cooler17, the second EGR valve16can be adjusted accordingly. If the second EGR valve16is fully opened and more flow through the second EGR path15and second EGR cooler17is required, the intake first throttle valve13, which is commonly a flapper-type valve, can be closed gradually.

Alternatively, in the second direction, the exhaust may pass through the variable turbine3and be introduced into a diesel particulate filter4, where the gas may be cleaned of various constituents that may include soot, carbon monoxide or hydrocarbons. After flowing through the diesel particulate filter4and the exhaust throttle5the exhaust gas then exits through the exhaust pipe6. The first EGR valve8can be opened to allow flow through the low-pressure loop66to the intake duct10and toward the compressor11of the turbocharger. Along this second direction, particulates may collect on the diesel particulate filter4, which may release small particulates that flow through the EGR path7to the compressor11. The particulates may form resin-like deposits of unburned hydrocarbons on the compressor blades. In addition, condensate or droplets from the exhaust gases may flow through the EGR path7to the compressor11.

SUMMARY OF EXEMPLARY EMBODIMENTS OF THE INVENTION

One embodiment of the invention is a product including a housing that has a mixer portion and first, second and third openings. The first opening is configured to receive at least a portion of exhaust gases produced by an internal combustion engine, and the second opening is configured to receive intake air. The mixer portion is in communication with the first and second openings to mix the exhaust gases and the intake air into a gas mixture. The third opening is in communication with the mixer portion to flow the gas mixture therethrough. The invention further includes a particulate separator disposed within the housing. The particulate separator is configured to remove particulates from the exhaust gases. The product may be included in a low-pressure EGR path and/or a high-pressure EGR path.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The following description of the embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses.

The inventors have recognized a need for a compact device that removes particulates from the recirculated exhaust gases and can be readily packaged within the EGR path.

One embodiment of the invention includes a product integrating multiple engine breathing system components including at least an EGR mixer and a particulate separator into a common housing. The module may be included in a low pressure EGR path and/or a high-pressure EGR path.

Referring now toFIG. 2, one embodiment of the invention may include an engine breathing system10including an intake conduit12, an exhaust conduit14, a turbocharger16, a recirculation conduit18and a product or mixer module20. The intake conduit12is configured to route intake air toward an internal combustion engine22, and the exhaust conduit14is configured to receive exhaust gases from the internal combustion engine22. The turbocharger16has a turbine portion24associated with the exhaust conduit14and a compressor portion26associated with the intake conduit12so that the compressor portion26compresses the intake air in the intake conduit in response to the exhaust gases rotating the turbine portion24in the exhaust conduit. The recirculation conduit18is a low-pressure exhaust gas recirculation path in communication between the exhaust conduit14and the intake conduit12for selectively recirculating at least a portion of the exhaust gases back to the internal combustion engine22. However, the recirculation conduit may instead be a high-pressure exhaust gas recirculation path. As detailed below, the mixer module20connects the recirculation conduit18to the intake conduit12for evenly mixing exhaust gases with the intake air and removing particulates from the exhaust gases.

Referring toFIGS. 3-5, the product or mixer module20has a housing28and a particulate separator30. The housing28has a mixer portion32and first, second and third openings34,36,38. The first opening34is configured to receive the exhaust gases from the recirculation conduit18, and the second opening36is configured to receive the intake air from one portion of the intake conduit12. The mixer portion32is in communication with the first and second openings34,36to mix the exhaust gases and the intake air into a gas mixture. The third opening38is in communication with the mixer portion32to flow the gas mixture therethrough into another portion of the intake conduit12.

As best shown inFIG. 4, the housing28further includes first and second conduits40,42with the mixer portion32being an integral part of the second conduit42. The first conduit40has an exhaust gas passage44in communication with the first opening34to receive the exhaust gases. The first conduit40substantially surrounds the mixer portion32, and the mixer portion32has a plurality of spaced apart openings46in communication with the exhaust gas passage44to receive the exhaust gases therefrom. The second conduit42has a mixing passage48that is in communication with the spaced apart openings46to receive the exhaust gases. The mixing passage48further includes one end portion in communication with the second opening36to receive the intake air and another end portion in communication with the third opening38to flow the gas mixture therethrough.

The housing28may be made of a one-piece casting or fabrication. Nevertheless, the housing28may instead be made of two or more separate components as desired.

The particulate separator30is disposed within the housing and configured to remove particulates from the exhaust gases. The particulate separator30(as best shown inFIGS. 4-5) may be a screen member or a filter mesh configured to collect particulates, debris and/or condensate from the exhaust gases. The particulate separator30may be various other suitable porous media as desired. The particular separator30may have a cylindrical shape and may have a through hole. The particulate separator30is coupled to the housing28by a friction fit, an insert molding, various suitable fasteners or any combination thereof. For instance, as exemplified in the embodiment shown inFIG. 5, the particulate separator30can have an end portion overmolded with elastic annular ridges50for snap-fitting within an annular channel of the housing28. Each ridge50is also a seal engaged to the particulate separator30so that the exhaust gases are directed through the particulate separator30. The mixer portion32surrounds the particulate separator30such that the particulate separator30is disposed within the mixing passage48of the second conduit42.

A method of operating the mixer module ofFIGS. 2-5will now be explained according to another embodiment of the invention.

At step200, the first opening34of the housing28routes at least a portion of exhaust gases produced by the engine into the exhaust gas passage44of the first conduit40.

Next at step202, the second opening36of the housing28routes intake air into the mixing passage48of the second conduit42.

Next at step204, the particulate separator30collects particulates from the exhaust gases within the housing28. This step may be accomplished by collecting particulates from the exhaust gases on a screen member or filter mesh within a low velocity profile of the exhaust gases in the exhaust gas passage44. Accordingly, the particulate separator30reduces the pressure drop of the exhaust gases. Nevertheless, this step may also be accomplished by the particulate separator30collecting particulates from the exhaust gases within the mixing passage48of the second conduit42.

Next at step206, the particulate separator30collects condensate thereon and then vaporizes the condensate.

Next at step208, the mixer portion32routes the intake air and the exhaust gases to mix the intake air and the exhaust gases into the gas mixture. This step may be accomplished by routing the exhaust gases radially inward from the exhaust gas passage44through the spaced apart openings46of the mixer portion32and into the mixing passage48.

Next at step210, the product or mixing passage48routes the gas mixture through the third opening38toward the compressor portion26of the turbocharger16.

Referring toFIGS. 6 and 7, a mixer module120is shown according to another embodiment of the invention. The mixer module120has a mixer portion132and a particulate separator130and is substantially similar to the mixer module20ofFIGS. 3-5having the mixer portion32and particulate separator30, respectively. However, in this embodiment, the particulate separator130surrounds the mixer portion132instead of the mixer portion surrounding the particulate separator. Accordingly, the particulate separator130is disposed in the exhaust gas passage144so that the particulate separator130removes the particulates and condensate from a low-velocity flow portion of the exhaust gases and reduces a pressure drop of the exhaust gases. The particulate separator130is coupled to the housing128by a friction fit, an insert molding, various suitable fasteners or any combination thereof.

The above description of embodiments of the invention is merely exemplary in nature and, thus, variations thereof are not to be regarded as a departure from the spirit and scope of the invention.