Tail pipe exhaust cooling device

An exhaust cooling device (10) is provided for an exhaust pipe (12) of a combustion process. The cooling device (10) includes a tubular housing (20) having an upstream portion (16) and a downstream portion (18), with the upstream portion (16) having a necked-down section (24) tapered in an upstream direction, and a plurality of openings (30) formed in the necked-down section (24) to allow an ambient air flow from an exterior of the tubular housing (20) to an interior of the tubular housing (20). The cooling device (10) further includes a nozzle element (22) fixed in the necked-down section (24) to direct an exhaust gas flow into the tubular housing (20).

FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable.

Not Applicable.

FIELD OF THE INVENTION

The disclosure relates generally to exhaust treatment devices and more specifically to a vehicle exhaust pipe component or attachment for reducing exhaust temperature and/or eliminating hot spots in the exhaust flow exiting a vehicle.

BACKGROUND OF THE INVENTION

Conventional tail pipe exhaust temperatures, especially for diesel particulate filter applications, show peaks as high as 650° C. Such exhaust gas temperatures can potentially ignite flammable materials, such as dry grass along a roadside. Hence, there is seen to be a need in the art for a component device for an exhaust system, such as a vehicle exhaust system including a tail pipe, for lowering the exhaust temperatures of the exhaust flow emanating from the vehicle.

SUMMARY OF THE INVENTION

In accordance with one feature of the invention, a exhaust cooling device is provided for an exhaust pipe of a combustion process. The cooling device includes a tubular housing having an upstream portion and a downstream portion, with the upstream portion having a necked-down section tapered in an upstream direction, and a plurality of openings formed in the necked down section to allow an ambient air flow from an exterior of the tubular housing to an interior of the tubular housing. The cooling device further includes a nozzle element fixed in the necked down section to direct an exhaust gas flow into the tubular housing.

As one feature of the invention, the necked-down section has a frusto-conical shape that tapers from a cylindrical shaped section of the upstream portion.

According to one feature, the nozzle element has a frusto-conical shape that tapers from in a downstream direction from an annular flange to a nozzle exit, with the annular flange of the nozzle fixed to a closely conforming annular flange of the necked-down section of the tubular housing.

In one feature, the nozzle element is formed on a terminal end of an exhaust pipe.

As one feature, the openings are circumferentially spaced around the necked-down section. In a further feature, each opening is elongate in the circumferential direction with a periphery defined by a circumferentially extending upstream edge, a circumferentially extending downstream edge, and two circumferentially spaced side edges extending connecting the upstream and downstream edges. In yet a further feature, at least the downstream edge is defined by an inwardly directed flange. As an additional feature, all of the edges are defined by an inwardly directed flange.

According to one feature, each of the openings has a periphery defined at least in part by an inwardly directed flange. As an additional feature, the inwardly directed flange is limited to a downstream portion of the periphery for each of the openings. In an alternate feature, the inwardly directed flange extends along the entire periphery for each of the openings.

In one feature, the cooling device further includes a debris shield spaced outwardly from the tubular housing and extending axially to over at least the necked down section of the tubular housing to restrict entry of debris through the openings.

In accordance with one feature of the invention, an exhaust cooling device is provided for an exhaust pipe of a combustion process. The cooling device includes a tubular housing having an upstream portion and a downstream portion connected by a cylindrical section of the housing, with the upstream portion having a frusto-conical shaped section tapered in an upstream direction, and a plurality of circumferentially spaced openings formed in the frusto-conical shaped section to allow an ambient air flow from an exterior of the tubular housing to an interior of the tubular housing. The cooling device further includes a frusto-conical shaped nozzle element tapered in the downstream direction and fixed in the upstream portion to direct an exhaust gas flow into the tubular housing.

As one feature, the nozzle element has an annular flange fixed to a closely conforming annular flange of the upstream portion of the tubular housing.

In one feature, the nozzle element is formed on a terminal end of an exhaust pipe.

According to one feature, each opening is elongate in the circumferential direction with a periphery defined by a circumferentially extending upstream edge, a circumferentially extending downstream edge, and two circumferentially spaced side edges extending connecting the upstream and downstream edges. As a further feature, at least the downstream edge is defined by an inwardly directed flange.

In one feature, each of the openings has a periphery defined at least in part by an inwardly directed flange. As an additional feature, the inwardly directed flange is limited to a downstream portion of the periphery for each of the openings. In an alternate additional feature, the inwardly directed flange extends along the entire periphery for each of the openings.

Other objects, features, and advantages of the invention will become apparent from a review of the entire specification, including the appended claims and drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference toFIG. 1, an exhaust cooling device10is intended preferably for coupling to a tail pipe12of a vehicular exhaust system, shown diagrammatically at14, to cool an exhaust gas flow, shown by arrow A. The cooling device10includes an upstream end portion16and a downstream end portion18with a cylindrical housing or pipe20extending between the upstream and downstream portions16and18, with the portion18preferably being an open end of the cylindrical housing/pipe20.

With reference toFIGS. 1-6, the upstream portion16includes a venturi forming element or nozzle22that is received in a necked-down section24of the housing/pipe20. The venturi/nozzle element22preferably has a frusto conical shape that is tapered in a downstream direction from an annular portion or flange26that is bonded, such as by welding or brazing, to a closely conforming annular flange28on the section24. Similarly, the annular flange28can be received in the downstream end of the tail pipe12that closely conforms to the flange28and is bonded thereto, again such as by welding or brazing. Alternatively, while the venturi/nozzle element22is shown as a separate piece part of the device10, it can optionally be provided in the form of a necked-down end portion of the tail pipe12that is shaped to the desired geometry for the nozzle/element22and received in the necked-down section24of the housing/pipe20. The section24includes a plurality (4 in the illustrated embodiment) of circumferentially spaced openings or windows30that allow a cooling air flow, shown by arrows B inFIG. 4, from the surrounding ambient environment to enter the device10for cooling of the exhaust flow A. In this regard, the frusto conical shape of the venturi/nozzle element22creates a higher exhaust flow velocity for the exhaust flow A as it exits the venturi/nozzle element22, resulting in a suction effect, which in turn draws the colder environmental ambient air B into the housing/pipe20for mixing and cooling the exhaust flow A. Each of the windows30preferably has an inwardly directed flange32that extends either over the entirety of the periphery of the window30, as shown inFIG. 6, or over at least part of the downstream periphery of the window30, as shown inFIGS. 3 and 4. In this regard, as seen in the embodiment ofFIGS. 3 and 4, the flange32is not located over the leading edge34of each window30.

Optionally, but preferably, a mud/debris shield40can be provided to extend axially over at least the end portion16and completely or at least partially circumferentially over the end portion16(as shown inFIG. 2) to limit or restrict mud and/or other debris from entering the device10via the windows30. The shield40can either be connected to the exhaust pipe12, to the housing/pipe20, or to another component or structure of the vehicle using any suitable connector, such as by bonding with braze or welding, or by use of a hose clamp or other suitable mechanical fastener. In this regard, suitable struts or legs, such as shown for example at42inFIG. 1can extend from the shield40to the housing/pipe20and/or the tail pipe12for mounting of the shield40.

It is preferred that the housing/pipe20have a sufficient length so that the end portion16is not generally visible to observer's in other vehicles or pedestrians passing the vehicle. In this regard, it will be appreciated that by providing the end portion16on the upstream end of the device10, the cooling device10can provide the vehicle with a standard looking exhaust pipe while also provide the desired cooling of the exhaust flow.

It should be appreciated that the geometrical specifics of the venturi/nozzle22and the windows30will be highly dependent upon the particular application, including, for example, the geometry of the mating parts (tail pipe12) of the exhaust system14, the temperature of the exhaust flow before it enters the device10, the desired outlet temperature of the exhaust flow, the volume of the exhaust flow during various operating conditions, the anticipated temperature range of the environmental ambient air that will be drawn into the device10for cooling, and the acceptable back pressure from the device10. Accordingly, other suitable shapes may be used for the venturi/nozzle22and/or windows30.