CN113950571B

CN113950571B - System and method for mixing exhaust gas and reductant in an aftertreatment system

Info

Publication number: CN113950571B
Application number: CN201980097368.5A
Authority: CN
Inventors: 刘志立; A·卡艳卡; 阿楚塔·蒙纳努尔; N·M·施密特; 大卫·李·邓纳克
Original assignee: Cummins Emission Solutions Inc
Current assignee: Cummins Emission Solutions Inc
Priority date: 2019-06-14
Filing date: 2019-06-14
Publication date: 2022-11-18
Anticipated expiration: 2039-06-14
Also published as: DE112019007452T5; BR112021025076A2; GB2598696B; WO2020250015A1; GB2598696A; DE112019007452B4; GB202117927D0; CN113950571A

Abstract

A vane vortex mixer for exhaust aftertreatment includes a vane vortex mixer inlet configured to receive exhaust gas and a vane vortex mixer outlet configured to provide exhaust gas to a catalyst. The vane vortex mixer also includes a first flow device configured to receive the exhaust gas from the vane vortex mixer inlet and to receive the reductant such that the reductant mixes with the exhaust gas within the first flow device. The first flow device includes a venturi body having a venturi central axis and defined by a body inlet and a body outlet. The first flow device also includes a plurality of upstream vanes positioned within the venturi body adjacent the body inlet. Each of the upstream blades is coupled to an upstream blade hub. The plurality of upstream blade holes are spaced between the plurality of upstream blades. The plurality of upstream vane apertures are configured to receive exhaust gas and cooperate with the plurality of upstream vanes to provide a swirling flow to the exhaust gas that promotes mixing of the reductant and the exhaust gas. Further, the first flow device includes a plurality of downstream vanes positioned within the venturi body and adjacent the body outlet. Each of the downstream blades is coupled to a downstream blade hub. The plurality of downstream vane apertures are spaced between the plurality of downstream vanes. The plurality of downstream vane holes are configured to receive the exhaust gas and cooperate with the plurality of downstream vanes to promote further mixing of the reductant and the exhaust gas. At least one of the upstream and downstream blade hubs is radially offset from the venturi central axis, thereby differentiating a geometry of each of the plurality of blades coupled to the radially offset blade hubs.

Description

System and method for mixing exhaust gas and reductant in an aftertreatment system

Technical Field

The present application relates generally to the field of aftertreatment systems for internal combustion engines, and more particularly to vane vortex mixers (vane vortex mixers) used in such aftertreatment systems.

Background

For internal combustion engines, such as diesel engines, nitrogen oxide (NOx) compounds may be emitted in the exhaust. To reduce NOx emissions, a Selective Catalytic Reduction (SCR) process may be implemented to convert NOx compounds to more neutral compounds, such as diatomic nitrogen or water, with the aid of a catalyst and a reductant. The catalyst may be included in a catalyst chamber of an exhaust system, such as a catalyst chamber of a vehicle or power generation unit. A reductant, such as anhydrous ammonia, aqueous ammonia, diesel Exhaust Fluid (DEF), or aqueous urea, is typically introduced into the exhaust gas stream prior to the catalyst chamber. To introduce the reductant into the exhaust gas stream for the SCR process, the SCR system may dose or otherwise introduce the reductant through a dosing module that vaporizes or injects the reductant into an exhaust pipe of the exhaust system upstream of the catalyst chamber. The SCR system may include one or more sensors to monitor conditions within the exhaust system.

Once the reductant is introduced into the exhaust gas stream, the two need to be mixed. WO 2018/226626 A1 discloses a multistage mixer configured to receive an exhaust gas and a reducing agent and mix the reducing agent with the exhaust gas to provide the exhaust gas mixed with the reducing agent to a catalyst. The present application recognizes that it would be advantageous to provide a substantially uniform flow of exhaust gas and reductant to the catalyst, to promote a substantially uniform distribution of reductant in the exhaust gas downstream of the multi-stage mixer, and to provide a relatively low pressure drop in a relatively compact space, as compared to conventional aftertreatment systems. Known multi-stage mixers use a venturi to introduce a swirling mixture into the exhaust gas flow and use the venturi radially offset from the central axis of the multi-stage mixer such that any reductant accumulated on the body of the venturi is substantially redistributed into the exhaust gas downstream of the multi-stage mixer.

However, known multi-stage mixers, while providing significant improvements over the prior art, are not scaled proportionally within the entire diesel engine system family due to space-demanding constraints. Accordingly, an improved mixer is desired in order to allow better scaling while still allowing any reductant accumulated on the venturi body to be substantially redistributed into the exhaust gas downstream of the mixer.

SUMMARY

In an embodiment, a vane vortex mixer for exhaust aftertreatment is centered about a mixer central axis and includes a vane vortex mixer inlet, a vane vortex mixer outlet, a first flow device, and a venturi body. The vane vortex mixer inlet is configured to receive exhaust gas. The blade vortex mixer outlet is configured to provide exhaust gas to the catalyst. The first flow device is configured to receive exhaust gas from the inlet of the vane vortex mixer and to receive a reductant such that the reductant mixes with the exhaust gas within the first flow device. The first flow device includes a venturi body defined by a body inlet in fluid communication with the vane vortex mixer inlet and a body outlet in fluid communication with the vane vortex mixer outlet. The venturi body includes a venturi central axis. A plurality of upstream vanes are positioned within the venturi body adjacent the body inlet, wherein each of the upstream vanes is coupled to an upstream vane hub. The plurality of upstream blade holes are spaced between the plurality of upstream blades. The plurality of upstream vane apertures are configured to receive exhaust gas and cooperate with the plurality of upstream vanes to provide a swirling flow to the exhaust gas that promotes mixing of the reductant and the exhaust gas. A plurality of downstream vanes are positioned within the venturi body adjacent the body outlet, wherein each of the downstream vanes is coupled to a downstream vane hub. A plurality of downstream vane apertures are spaced between the plurality of downstream vanes, and the plurality of downstream vane apertures are configured to receive the exhaust gas and cooperate with the plurality of downstream vanes to promote mixing of the reductant and the exhaust gas.

At least one of the upstream and downstream blade hubs is radially offset from the venturi central axis, thereby differing a geometry of each of the plurality of upstream blades and/or a geometry of each of the plurality of downstream blades, as the case may be.

In this embodiment, the offset, and thus the variable geometry, of the mixer blades effectively redistributes the reductant within the swirling flow. At the same time, other components may be centered on the main axis of the vane vortex mixer, allowing the concentric portions to be more easily scaled and manufactured for various sizes of engines and exhaust systems.

The downstream blade hub may not be radially offset from the venturi central axis. An alternative definition of this arrangement is that the downstream vane hub is centered about the venturi central axis.

This embodiment enables the vane vortex mixer to mix the reductant and exhaust gas efficiently within the first flow device, whilst simultaneously making the exhaust gas flow downstream of the downstream vanes more central, thereby allowing for greater efficiency of the catalyst.

Each of the plurality of upstream blades may be defined by an upstream blade angle between an upstream blade hub center axis of the upstream blade hub and an upstream blade plane. The upstream blade hub central axis may be parallel to the venturi central axis. The upstream vane angle of each of the plurality of upstream vanes may be between forty-five and ninety degrees, and the upstream vane angle of one of the plurality of upstream vanes may be different from the upstream vane angle of another of the plurality of upstream vanes.

Each of the plurality of downstream blades may be defined by a downstream blade angle between a downstream blade hub center axis of the downstream blade hub and a downstream blade plane. The downstream blade hub central axis may be parallel to the venturi central axis. The downstream blade angle of each of the plurality of downstream blades may be between forty-five degrees and ninety degrees, and the downstream blade angle of one of the plurality of downstream blades may be different from the downstream blade angle of another of the plurality of downstream blades.

Optionally, each of the plurality of upstream vanes and/or the plurality of downstream vanes is coupled to and conforms with the venturi body (conform).

The plurality of upstream vanes and the plurality of downstream vanes may be duct straightening vanes. Adjacent duct straight blades form ducts between them. The ducts have a streamwise direction (streamwise direction) defined by the bisector of the angle of the plane of the straight vanes of the adjacent ducts. A flow direction angle is defined between a plane of the catheter straight blade and a hub central axis of the catheter straight blade hub. The hub central axis of the catheter straight blade hub is parallel to the venturi central axis. The flow direction angle of each of the plurality of conduit straight vanes may be between thirty and ninety degrees (including thirty and ninety degrees), and the flow direction angle of one of the plurality of conduit straight vanes may be different than the flow direction angle of another of the plurality of conduit straight vanes.

If the blade, whether it is an upstream blade or a downstream blade, is not a straight blade, but has at least one of a twist (twist) in the radial direction and a bend (curve) in the circumferential direction, the plane of the blade is determined by using at least one of the appropriate cut lines as a reference.

A secant suitable for twisting is drawn from the end of the blade at the hub to the radially outer end at each of the leading and trailing edges of the blade. The secant is then projected circumferentially onto a radius of one half of the circumference of the blade, thereby determining the bisector of the two projected secants. The angle bisector is then projected again in the circumferential direction back to the leading and trailing edges. The plane defined by the two bisectors of the projection angle is used as a reference.

A cut line adapted to the bending will be drawn from the leading edge to the trailing edge at both the blade end at the hub and the radially outer end. The plane defined by these two secants is used as a reference.

Each of the plurality of conduit straight vanes may be coupled to and conform with the venturi body such that each of the plurality of conduit straight vanes cooperates with the venturi body to form a conduit.

One of the plurality of conduit straight vanes may extend an extension distance above another of the plurality of conduit straight vanes. One of the plurality of duct straight blades has a width in the flow direction. The extension distance may be between zero percent and seventy-five percent of a width in a flow direction of one of the plurality of duct straight vanes.

The venturi body may include an exhaust gas guide hole disposed along the venturi body between the body inlet and the body outlet.

The exhaust gas guide holes may be circular, alternatively elliptical. The elliptical guide holes may be sized to have the same open area as the circular exhaust gas guide holes while allowing the venturi body to require a shorter length in the axial direction of the mixer central axis and reducing the spacing between the upstream and downstream mixers. Reducing the spacing between the mixers increases the available volume between the downstream mixer and the SCR inlet, promotes better decomposition and mixing of the reductant, and increases the efficiency of the SCR system to reduce NOx emissions.

The blade vortex mixer may include a reducing agent dispenser through which the reducing agent is introduced into the blade vortex mixer. The dispenser may be positioned around the vent gas introduction hole. In the latter case, the dispenser and the exhaust gas directing holes are placed in the vertical mid-plane of the blade vortex mixer to direct the reducing agent toward the mixer central axis. Alternatively, the dispenser and exhaust gas guide holes are placed at a vertical mid-plane offset from the vane vortex mixer, directing the reducing agent towards the venturi wall. The offset may be correlated to the offset of the blade hubs of the upstream and/or downstream mixers. If the dispenser is not positioned around the exhaust gas guide holes, only the dispenser may be placed on the vertical mid-plane of the blade vortex mixer directing the reducing agent toward the mixer central axis, or alternatively, at a vertical mid-plane offset from the blade vortex mixer directing the reducing agent toward the venturi wall. This offset may again be correlated with the offset of the blade hubs of the upstream and/or downstream mixers.

In one embodiment, the venturi central axis is radially offset from the mixer central axis. Alternatively, and as also described below and shown in the figures, the venturi central axis is centered on the mixer central axis.

Various aspects of the invention may be implemented in one or more of the following embodiments.

1) A vane vortex mixer for exhaust aftertreatment, the vane vortex mixer centered about a mixer central axis, the vane vortex mixer comprising:

a vane vortex mixer inlet configured to receive exhaust gas;

a vane vortex mixer outlet configured to provide the exhaust gas to a catalyst;

a first flow device configured to receive the exhaust gas from the vane vortex mixer inlet and to receive a reductant such that the reductant mixes with the exhaust gas within the first flow device, the first flow device comprising:

a venturi body defined by a body inlet and a body outlet, the venturi body having a venturi central axis;

a plurality of upstream vanes positioned within the venturi body adjacent the body inlet, wherein each of the upstream vanes is coupled to an upstream vane hub; and

a plurality of upstream vane apertures spaced between the plurality of upstream vanes, the plurality of upstream vane apertures configured to receive the exhaust gas and cooperate with the plurality of upstream vanes to provide a swirling flow to the exhaust gas that promotes mixing of the reductant and the exhaust gas; and

a plurality of downstream vanes positioned within the venturi body adjacent the body outlet, wherein each of the downstream vanes is coupled to a downstream vane hub; and

a plurality of downstream vane apertures spaced between the plurality of downstream vanes, the plurality of downstream vane apertures configured to receive the exhaust gas and cooperate with the plurality of downstream vanes to facilitate further mixing of the reductant and the exhaust gas; and is

Wherein at least one of the upstream and downstream blade hubs is radially offset from the venturi central axis, thereby differing a geometry of each of the plurality of blades coupled to the radially offset blade hub.

2) The blade vortex mixer of item 1) wherein the downstream blade hub is centered about the venturi central axis.

3) The blade vortex mixer of item 1) or item 2), wherein

Each of the plurality of upstream blades is defined by an upstream blade angle between an upstream blade hub center axis of the upstream blade hub and a plane of the upstream blade, the upstream blade hub center axis being parallel to the venturi center axis;

the upstream blade angle of each of the plurality of upstream blades is between forty-five and ninety degrees, including forty-five and ninety degrees; and is

Optionally, the upstream blade angle of one of the plurality of upstream blades is different from the upstream blade angle of another of the plurality of upstream blades.

4) The blade vortex mixer of item 2) or item 3), wherein

Each of the plurality of downstream blades is defined by a downstream blade angle between a downstream blade hub central axis of the downstream blade hub and a plane of the downstream blade, the downstream blade hub central axis being parallel to the venturi central axis;

the downstream blade angle of each of the plurality of downstream blades is between forty-five and ninety degrees, including forty-five and ninety degrees; and is provided with

Optionally, the downstream blade angle of one of the plurality of downstream blades is different from the downstream blade angle of another of the plurality of downstream blades.

5) The vane vortex mixer of any one of the preceding claims, wherein each of the plurality of upstream vanes and at least one of the plurality of downstream vanes are coupled to and conform with the venturi body such that each of the coupled and conforming vanes cooperates with the venturi body to form a conduit.

6) The blade vortex mixer according to item 1) or item 2), wherein

At least one of the plurality of upstream vanes and the plurality of downstream vanes is a duct straight vane, wherein

Adjacent duct straight blades form a duct therebetween, the duct having a flow direction defined by an angular bisector of the planes of the adjacent duct straight blades;

a flow direction angle is defined between the flow direction and a hub central axis of the catheter straight vane hub, the hub central axis of the catheter straight vane hub being parallel to the venturi central axis;

the flow direction angle of each of the plurality of conduit straight vanes is between thirty and ninety degrees, including thirty and ninety degrees; and is

Wherein optionally the flow direction angle of one of the plurality of duct straight vanes is different from the flow direction angle of another one of the plurality of duct straight vanes.

7) The blade vortex mixer of item 6), wherein

Each of the plurality of conduit straight vanes is coupled to and conforms to the venturi body such that each of the plurality of conduit straight vanes cooperates with the venturi body to form a conduit.

8) The blade vortex mixer according to item 6) or item 7), wherein

One of the plurality of conduit straight blades extends an extension distance above another of the plurality of conduit straight blades;

said one of said plurality of duct straight vanes having a width in said flow direction; and is

The extension distance is between zero percent and seventy-five percent, including zero percent and seventy-five percent, of the flow direction width of the one of the plurality of duct straight vanes.

9) The vane vortex mixer of any one of the preceding claims wherein

The venturi body includes a discharge gas guide hole provided along the venturi body between the body inlet and the body outlet.

10 Blade vortex mixer according to item 9), wherein

The discharge gas guide hole is one of circular and elliptical.

11 Blade vortex mixer according to one of the preceding claims, further comprising a reducing agent dispenser for introducing the reducing agent into the blade vortex mixer along an axis, wherein preferably

The angle (γ) between the reductant introduction axis and the circumferentially nearest radial edge of the vane will be at

Where n is the number of blades.

12 Blade vortex mixer according to item 11) when depending on item 9), wherein

The dispenser is positioned around the vent gas guide aperture.

13 Blade vortex mixer according to item 12), wherein

The dispenser and the exhaust gas directing holes are positioned on a vertical mid-plane of the blade vortex mixer to direct the reducing agent toward the mixer central axis.

14 Blade vortex mixer according to item 12), wherein

The dispenser and the exhaust gas directing holes are positioned offset from a vertical mid-plane of the blade vortex mixer to direct the reducing agent toward a venturi wall.

15 Blade vortex mixer according to any of the preceding claims, wherein

The venturi central axis is radially offset from the mixer central axis.

16 Diesel exhaust unit comprising a flow-through catalyst or a wall-flow catalyst and a vane swirl mixer according to one of the preceding claims.

The blade vortex mixer may be part of a multi-stage mixer, such as the one shown in WO 2018/226626 A1.

Brief Description of Drawings

The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features, aspects, and advantages of the disclosure will become apparent from the description, the drawings, and the claims, wherein:

FIG. 1 is a schematic block diagram of an example selective catalytic reduction system having an example reductant delivery system for an exhaust system;

FIG. 2 is a cross-sectional view of a blade vortex mixer and dispenser;

FIG. 3 is a front view of a mixer for a vane vortex mixer;

FIG. 4 is a cross-sectional view similar to FIG. 2 showing further dimensions of the vane vortex mixer;

FIG. 5 is a cross-sectional view of another vane vortex mixer;

FIG. 6 is a view of the upstream face of a vane vortex mixer, illustrating a design that may be implemented in any of the vane vortex mixers shown and described herein;

FIG. 7A is a side view of another mixer for a vane vortex mixer;

FIG. 7B is another side view of the mixer shown in FIG. 7A;

FIG. 8 is a bottom perspective view of yet another mixer for a vane vortex mixer;

FIG. 9 is a top perspective view of yet another mixer for a vane vortex mixer;

FIG. 10 is a side cross-sectional view of the mixer of FIG. 9;

FIG. 11 is a graph showing the results of comparing a previous mixer with an embodiment of a vane vortex mixer in accordance with the present invention.

It should be appreciated that some or all of the figures are schematic representations for purposes of illustration. These drawings are provided for the purpose of illustrating one or more embodiments and are not to be construed as limiting the scope or meaning of the claims.

Detailed Description

Following are more detailed descriptions of various concepts related to and embodiments of methods, apparatus and systems for flow distribution in an aftertreatment system. The various concepts introduced above and discussed in greater detail below may be implemented in any of numerous ways, as the concepts described are not limited to any particular manner of implementation. Examples of specific embodiments and applications are provided primarily for illustrative purposes.

I. Overview

Internal combustion engines (e.g., diesel internal combustion engines, etc.) generate exhaust gases that are typically treated in aftertreatment systems. Such treatment typically includes passing the exhaust gas through a catalyst. By providing a uniform flow of exhaust gas to the catalyst, the efficiency of the catalyst, and thus the efficiency of the aftertreatment system, may be increased. Various components, such as baffles, may be included within the aftertreatment system to alter the flow of exhaust gas into the catalyst. Conventional aftertreatment systems implement components that are difficult to scale (e.g., for different applications, etc.) in both the radial direction (e.g., various diameters, etc.) and the axial direction (e.g., various lengths, various numbers of components, various configurations of components, etc.). For example, the baffle may have complex shapes that require advanced manufacturing techniques and thus higher cost to produce. Thus, conventional aftertreatment systems do not provide the flexibility necessary to be easily implemented in applications where engine power and/or operating conditions vary. Furthermore, conventional aftertreatment systems typically utilize complex components that are expensive and require difficult and time intensive manufacturing.

Embodiments described herein relate to a vane vortex mixer that includes a plurality of flow devices that cooperate to provide a substantially uniform flow of exhaust gas and reductant to a catalyst, promote substantially uniform reductant distribution in the exhaust gas downstream of a multi-stage mixer, and provide a relatively low pressure drop (e.g., exhaust gas pressure at an inlet of the multi-stage mixer is less than exhaust gas pressure at an outlet of the multi-stage mixer, etc.), all within a relatively compact space compared to conventional aftertreatment systems. The flow device is relatively easy to manufacture compared to the complex devices currently used in aftertreatment systems. Thus, the vane vortex mixer can be easily and easily scaled for various applications while consuming less physical space than the equipment currently used in aftertreatment systems. The multi-stage mixer may be configured to dose the reducing agent to the exhaust gas to cause an internal swirling flow of the mixed reducing agent in the exhaust gas and to produce a uniform distribution of the reducing agent in a uniform flow of the exhaust gas flowing into the catalyst. The vane vortex mixer can minimize jet impingement on the wall surface due to the vortex flow and the relatively high shear stress generated on the wall by the vane vortex mixer, thereby mitigating the formation and accumulation of deposits within the vane vortex mixer and associated exhaust components.

In some embodiments, the vane vortex mixer includes an exhaust gas guide that guides exhaust gas toward a reductant sprayed from the reductant guide. The exhaust gas flows into the exhaust gas guide via holes provided on at least a portion of the exhaust gas guide. The exhaust gas then assists the reductant to travel into the flow device, whereby the reductant and the exhaust gas may subsequently mix via a swirling flow. Mixing can improve decomposition, enhance general diffusion and turbulent diffusion, and prolong the mixing trajectory of the exhaust gas and the reducing agent by utilizing the low pressure created by the vortex flow and/or the venturi flow. Vortex flow refers to a flow that swirls around the central axis of the vane vortex mixer and/or the central axis of the flow device. Venturi flow refers to flow created by a low pressure region due to a reduction in cross-sectional area and local acceleration of flow.

In some embodiments, the flow device of the vane vortex mixer includes an inner plate located below the reductant guide. As the reducing agent flows into the flow device, the reducing agent contacts the interior plates, which promote mixing of the reducing agent in the exhaust gas by reducing the stokes number of the reducing agent (e.g., reducing agent droplets, etc.) via splashing.

The design characteristics of the vane vortex mixer can be optimized to accommodate a wide range of aspect ratios (L/D) of the mixer to achieve proportional changes in the isotropic and anisotropic geometry of the mixer design. These features can be combined to design a mixer with a larger venturi diameter while achieving the same flow profile.

Overview of the aftertreatment System

FIG. 1 depicts an aftertreatment system 100 having an example reductant delivery system 110 for an exhaust system 190. The aftertreatment system 100 includes a particulate filter, such as a Diesel Particulate Filter (DPF) 102, a reductant delivery system 110, a decomposition chamber or reactor 104, an SCR catalyst 106, and a sensor 150. In some embodiments, the SCR catalyst 106 includes an ammonia oxidation catalyst (ASC).

The DPF 102 is configured to remove particulate matter, such as soot, from the exhaust gases flowing in the exhaust system 190. The DPF 102 includes an inlet that receives exhaust gases and an outlet that exhausts the exhaust gases after substantially filtering particulate matter from the exhaust gases and/or converting the particulate matter into carbon dioxide. In some embodiments, the DPF 102 can be omitted.

The decomposition chamber 104 is configured to convert a reductant (such as urea or DEF) to ammonia. Decomposition chamber 104 includes a reducing agent delivery system 110, the reducing agent delivery system 110 having a dispenser or dosing module 112, the dispenser or dosing module 112 configured to dose reducing agent into decomposition chamber 104 (e.g., via an injector, such as the injector described below). In some embodiments, the reductant is injected upstream of the SCR catalyst 106. The reductant droplets then undergo evaporation, pyrolysis, and hydrolysis processes to form gaseous ammonia within the exhaust system 190. Decomposition chamber 104 includes an inlet in fluid communication with DPF 102 to receive exhaust gas containing NOx emissions and an outlet for exhaust gas, NOx emissions, ammonia, and/or reductants to flow to SCR catalyst 106.

Decomposition chamber 104 includes a dosing module 112 mounted to decomposition chamber 104 such that dosing module 112 may dose reductant into exhaust gases flowing in exhaust system 190. The dosing module 112 may include an insulator 114 interposed between a portion of the dosing module 112 and the portion of the decomposition chamber 104 in which the dosing module 112 is installed. The dosing module 112 is fluidly coupled to one or more reductant sources 116. In some embodiments, the pump 118 may be used to pressurize the reductant from the reductant source 116 for delivery to the dosing module 112.

The dosing module 112 and the pump 118 are also electrically connected or communicatively coupled to a controller 120. The controller 120 is configured to control the dosing module 112 to dose the reductant into the decomposition chamber 104. The controller 120 may also be configured to control the pump 118. The controller 120 may include a microprocessor, an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA), the like, or combinations thereof. The controller 120 may include a memory that may include, but is not limited to, an electronic, optical, magnetic, or any other storage or transmission device capable of providing program instructions to a processor, ASIC, FPGA, or the like. The memory may include a memory chip, an electrically erasable programmable read-only memory (EEPROM), an erasable programmable read-only memory (EPROM), a flash memory, or any other suitable memory from which the controller 120 may read instructions. The instructions may include code from any suitable programming language.

SCR catalyst 106 is configured to assist in reducing NOx emissions by accelerating the NOx reduction process between ammonia and NOx in the exhaust gas to diatomic nitrogen and water. SCR catalyst 106 includes an inlet in fluid communication with decomposition chamber 104 (from which decomposition chamber 104 the exhaust gas and reductant are received) and an outlet in fluid communication with an end of exhaust system 190.

The exhaust system 190 may also include an oxidation catalyst (e.g., a Diesel Oxidation Catalyst (DOC)) in fluid communication with the exhaust system 190 (e.g., upstream of the SCR catalyst 106 or the DPF 102) to oxidize hydrocarbons and carbon monoxide in the exhaust gas.

In some embodiments, the DPF 102 can be positioned downstream of the decomposition chamber or reactor 104. For example, the DPF 102 and the SCR catalyst 106 may be combined into a single unit. In some embodiments, the dosing module 112 may alternatively be positioned downstream of a turbocharger or upstream of a turbocharger.

The sensor 150 may be coupled to the exhaust system 190 to detect a condition of the exhaust gas flowing through the exhaust system 190. In some embodiments, the sensor 150 may have a portion disposed within the exhaust system 190; for example, the tip of the sensor 150 may extend into a portion of the exhaust system 190. In other embodiments, the sensor 150 may receive the exhaust gas through another conduit (such as one or more sample tubes extending from the exhaust system 190). Although the sensor 150 is depicted as being positioned downstream of the SCR catalyst 106, it should be understood that the sensor 150 may be positioned in any other location of the exhaust system 190, including: upstream of the DPF 102, within the DPF 102, between the DPF 102 and the decomposition chamber 104, within the decomposition chamber 104, between the decomposition chamber 104 and the SCR catalyst 106, within the SCR catalyst 106, or downstream of the SCR catalyst 106. Further, two or more sensors 150 may be used to detect the condition of the exhaust gas, such as two, three, four, five, or six sensors 150, each sensor 150 being located at one of the aforementioned locations of the exhaust system 190.

Example blade vortex mixer

FIG. 2 depicts a vane vortex mixer 200 according to an example embodiment. Although the vane vortex mixer 200 is described in this particular embodiment, it is not necessary to provide any additional features to the impellerIt should be understood that the related structures in this and similar embodiments may include other aftertreatment components, such as SCR catalysts, perforated pipes, tubes, manifolds, decomposition chambers or reactors, dispensers, dispensing modules, and the like. The vane vortex mixer 200 is configured to receive exhaust gases (e.g., combustion gases from an internal combustion engine, etc.) and provide a substantially uniform flow distribution (e.g., flow profile, etc.) to the downstream exhaust gases. According to example embodiments, the vane vortex mixer 200 is also configured to selectively dose a reductant (e.g., urea, diesel Exhaust Fluid (DEF)) into the exhaust gas,

Etc.). Because the vane vortex mixer 200 provides a substantially uniform flow distribution of the exhaust gas and promotes mixing between the exhaust gas and the reductant, the vane vortex mixer 200 may also provide a substantially uniform reductant distribution (e.g., reductant profile, etc.) to the downstream exhaust gas.

The vane vortex mixer 200 includes a vane vortex mixer inlet 202 that receives exhaust gas entering the vane vortex mixer 200 and a vane vortex mixer outlet 204 that provides exhaust gas from the vane vortex mixer 200. According to various embodiments, the vane vortex mixer inlet 202 receives exhaust gas from a diesel particulate filter (e.g., DPF 102, etc.), and the vane vortex mixer outlet 204 provides the exhaust gas to the SCR catalyst 106.

The flow of a fluid may be defined by a Reynolds number, which is related to the flow pattern of the fluid, and a Stokes number, which is related to the behavior of particles suspended in the fluid. Depending on the reynolds number, the flow may be, for example, turbulent or laminar. The flow of exhaust gas entering the vane vortex mixer inlet 202 may be varied from greater than 1e ⁴ Is defined, which indicates that the flow of the exhaust gas is turbulent. Since the flow of exhaust gas entering the vane vortex mixer inlet 202 is turbulent, there is a self-similarity. Depending on the stokes number, the particles may be more or less likely to follow the flow of the fluid. The flow of the reducing agent may be controlled byA stokes number like 1 is defined, indicating that the reducing agent is less likely to follow the flow of the exhaust gas, which causes problems in conventional mixing devices. Advantageously, vane vortex mixer 200 incorporates various components and devices herein that cause the reducing agent to mix with the exhaust gas (e.g., by reducing the stokes number of the reducing agent, etc.), thereby causing the reducing agent to be propelled through vane vortex mixer 200 along with the exhaust gas. In this way, the vane vortex mixer 200 improves reductant mixing and reduces the risks associated with the formation of deposits within the vane vortex mixer 200. In various embodiments, the vane vortex mixer 200 is static and has no components that move in response to exhaust gas passing through the vane vortex mixer 200. Thus, the vane vortex mixer 200 may be less complex and less expensive to manufacture than an aftertreatment component having moving parts, and is therefore more desirable.

The vane vortex mixer 200 includes a plurality of flow devices that divide the vane vortex mixer 200 into a plurality of stages. Each of the plurality of flow devices is configured to alter the flow of the exhaust gas and the reductant such that the plurality of flow devices cumulatively achieve a target flow distribution of the exhaust gas at the vane vortex mixer outlet 204 and a target uniformity index (e.g., uniformity distribution, etc.) of the reductant. It is important to obtain a certain flow distribution and reductant uniformity index in the operation of the aftertreatment system. For example, it is desirable to obtain a uniform flow distribution and reductant uniformity index at the inlet of the SCR catalyst, as such a flow distribution allows the SCR catalyst to achieve relatively high conversion efficiency.

As shown in fig. 2, the vane vortex mixer 200 includes a first flow device 206.

The blade vortex mixer 200 includes a dispenser 214 and a port 216, and a reducing agent (e.g., reducing agent droplets, etc.) is selectively introduced into the blade vortex mixer 200 from the dispenser 214 through the port 216. The vane vortex mixer 200 evenly distributes the reductant in the exhaust gas flowing from the vane vortex mixer outlet 204 of the vane vortex mixer 200. The port 216 is configured to direct or assist in directing the reductant toward the center (e.g., center axis, domain center, etc.) of the vane vortex mixer 200 regardless of the conditions (e.g., flow rate, temperature, etc.) of the exhaust gas. For example, the ports 216 may have various shapes and/or thicknesses to direct the reductant toward the center of the multi-stage mixer 200. Alternatively, the port 216 may be configured to direct or assist in directing the reductant off-center (e.g., center axis, domain center, etc.) of the vane vortex mixer. For example, the port 216 may be offset from a central axis of the vane vortex mixer to direct the flow of reductant toward a sidewall of the first flow device.

In some embodiments, the vane vortex mixer 200 also includes a reductant guide (e.g., a nozzle, a perforated pipe, etc.) that at least partially protects the reductant from the flow of exhaust gases from the vane vortex mixer inlet 202 to facilitate directing the reductant to the center of the vane vortex mixer 200. A reductant guide extends from port 216, receives reductant from dispenser 214, and provides reductant into blade vortex mixer 200 (e.g., at the center of blade vortex mixer 200, etc.). In various embodiments, the reductant guide is frustoconical.

Due to the particular configuration and structure of the vane vortex mixer 200, the vane vortex mixer 200 may be scaled and may be easily configured while maintaining the ability to provide exhaust gas with a highly uniform flow and reductant profile, while minimizing the pressure drop experienced by the exhaust gas and minimizing the potential for deposit (e.g., urea deposit, etc.) formation. Thus, the vane vortex mixer 200 can be configured for a target application at a lower cost (i.e., due to the scalable variability, modularity, etc. of the vane vortex mixer 200) than other mixers that cannot be easily adapted. The vane vortex mixer 200 and its components are scalable in the axial direction (e.g., length, etc.) and the radial direction (e.g., diameter, etc.).

Being scalable, the vane vortex mixer 200 can be used in a variety of applications where different lengths and/or diameters of the vane vortex mixer 200 are desired. For example, a vane vortex mixer may be produced for use with an aftertreatment system of one size marine vessel, and produced for use with an aftertreatment system of another size diesel commercial vehicle.

Due to the flexibility of the vane vortex mixer 200, the vane vortex mixer 200 can be manufactured at a lower cost than conventional aftertreatment devices, and can be easily customized for many specific applications, making the vane vortex mixer 200 more desirable than conventional aftertreatment devices. Furthermore, the blade vortex mixer 200 may be configured for retrofit or embedded applications (drop-in applications).

The first flow device 206 is shown as including a funnel-shaped rim 300, a venturi body 302, and a first support flange 304 (e.g., a downstream support flange, etc.). The funnel edge 300 abuts the venturi body 302, which venturi body 302 abuts the first support flange 304. The funnel edge 300 is configured to direct a majority of the exhaust gas from the vane vortex mixer inlet 202 to the venturi body 302. However, the funnel-shaped rim 300 allows a portion of the exhaust gas to initially bypass the venturi body 302 and enter the region between the first flow device 206 and the vane vortex mixer 200. The funnel edge 300 can have various angles (e.g., ninety degrees, forty-five degrees, thirty degrees, fifteen degrees, etc.) relative to the central axis of the blade vortex mixer 200. Further, the funnel edge 300 can have various heights relative to an outer edge of the body (e.g., relative to an outer diameter of the body, etc.), as will be explained in more detail herein. By adjusting the height of the funnel edge 300, more or less exhaust gas may be directed into the first flow device 206, more or less exhaust gas may be directed around the first flow device 206 (e.g., in a circuitous flow, etc.).

The venturi body 302 may be circular, conical, frustoconical, aerodynamically shaped, or other similar shape. First support flange 304 functions to couple first flow device 206 to blade vortex mixer 200. In various embodiments, first support flange 304 provides a seal between venturi body 302 and vane vortex mixer 200 such that any exhaust gas does not pass through or around first support flange 304. Accordingly, exhaust gas is redirected upstream from the first support flange 304 to enter the venturi body 302. However, as explained in more detail herein, in some embodiments, the first support flange 304 has apertures through which exhaust gas may pass through the first flow device 206.

According to various embodiments, the diameter of the venturi body 302 is:

0.25D ₀ ≤d _V ≤0.9D ₀ (1)

wherein the venturi body 302 is formed from a diameter d _V The blade vortex mixer 200 is defined by a ratio greater than d _V Inner diameter D of ₀ And (4) limiting. The static pressure measured at the venturi body 302 is given by:

wherein P is _C Is the absolute static pressure at the venturi body 302, where P ₀ Is the absolute static pressure upstream of the venturi body 302 (e.g., measured by a pressure sensor, measured by a sensor, etc.), where ρ is the density of the exhaust gas, and where v is ₀ Is the flow rate upstream of the venturi body 302 (e.g., as measured by a sensor, etc.). The venturi body 302 creates a low pressure region due to the difference in diameter between the venturi body 302 and the vane vortex mixer 200. The low pressure region enhances (e.g., increases, accelerates, etc.) decomposition of the reductant (e.g., via evaporation, via pyrolysis, etc.), normal and turbulent diffusion, and mixing of reductant droplets.

The first flow device 206 also includes an upstream mixer 1106 having a plurality of upstream vanes 1108 and a plurality of upstream vane apertures 1112 (see fig. 3) spaced between the plurality of upstream vanes 1108 to provide a swirling flow to create additional low pressure areas and promote mixing by extending the mixing trajectory of the first flow device 206. The upstream mixer 1106 is configured to receive exhaust gas from the vane vortex mixer inlet 202 and provide the exhaust gas into the venturi body 302. The upstream blade 1108 is also attached to an upstream blade hub 1109 and conforms to the upstream blade hub 1109, the upstream blade hub 1109 being radially offset from the central axis of the venturi body 302. Since the radial distance from the upstream blade hub to the venturi body varies according to the radial direction, the radial offset creates variable geometry blades. The deviation may be in the following range:

0≤HU _{deviation from} ≤0.25d _V (3)

Wherein d is _V Is the venturi diameter and HU _{Deviation from} Is the radial offset of the upstream vane hub center relative to the venturi central axis, the upstream vane hub center and the venturi central axis being respectively radially offset from the mixer central axis, as shown in fig. 3.

The respective angles may also be varied to obtain a desired flow split ratio (flow split) between the different blades. The variable geometry vane design may be optimized to preferentially redirect flow to increase droplet trajectories and thereby improve mixing of the reductant droplets with the exhaust gas, as well as to achieve high shear velocities on the venturi walls to minimize the potential for deposit (e.g., urea deposits, etc.) formation.

The upstream vane 1108 is static and does not move within the venturi body 302. In this manner, the upstream mixer 1106 is less complex and less expensive to manufacture, and thus more desirable, than an aftertreatment component having a complex component that is expensive and requires difficult and time consuming manufacturing. Rather than the upstream vanes 1108 confining the exhaust gas flow in a single path to create a vortex, several openings are provided between adjacent upstream vanes 1108 such that each of the upstream vanes 1108 independently swirls the exhaust gas and such that the upstream vanes 1108 collectively create a vortex flow in the exhaust gas.

The upstream vanes 1108 are positioned (e.g., curved, angled, bent, etc.) to create a swirling (e.g., mixing, etc.) flow of the exhaust gas and the reductant to form a mixture. In various embodiments, the upstream blade 1108 is substantially straight (e.g., disposed substantially along a plane, having a substantially constant pitch along the upstream blade 1108, etc.). In other embodiments, the upstream blade 1108 is curved (e.g., not substantially disposed along a plane, having a different pitch along the upstream blade 1108, having a curved edge relative to the remainder of the upstream blade 1108, etc.). In still other embodiments, adjacent upstream blades 1108 are positioned to extend above each other. In these embodiments, the upstream vanes 1108 may be straight and/or curved. In embodiments having multiple upstream blades 1108, each upstream blade 1108 may be independently configured such that the upstream blades 1108 are individually customized to achieve a target configuration of the first flow device 206 such that the blade vortex mixer 200 is customized for a target application.

Each of the upstream blades 1108 is defined by a blade angle (e.g., relative to a blade hub central axis, etc.) that is related to the vortex generated by the upstream blade 1108. The blade angle may be defined between a blade edge line (e.g., a line coaxial with the radially outermost circumferential edge of the angled portion of the blade) and a blade hub central axis. If the blade edge line and the blade hub centre axis do not intersect, the blade angle is defined between the blade hub centre axis and a plane defined by the intersection of the blade edge line and the blade hub centre axis with the plane formed by the upstream edge of the blade. The blade angle of each of the upstream blades 1108 may be different from the blade angle of any other upstream blade 1108. According to various embodiments, the first flow device 206 includes upstream vanes 1108, the upstream vanes 1108 having a vane angle between 45 degrees and 90 degrees. Similarly, the first flow device 206 may include any number of upstream vanes 1108. In some embodiments, the first flow device 206 includes four to twelve upstream vanes 1108.

The upstream blade apertures 1112 collectively define an open area A _I . However, the size of the upstream blade apertures 1112 is related in part to the diameter of the upstream blade hub 1109. According to various embodiments, the diameter of the upstream blade hub 1109 is given by:

0.05d _V ≤D _H ≤0.25d _V (4)

wherein D _H Is the diameter of the upstream blade hub 1109. In application, any of the number of upstream vanes 1108, the vane angle of the upstream vanes 1108, and the diameter of the upstream vane hub 1109 may be varied to optimize the improvement in the flow of exhaust gas and reductant, the improvement in reductant mixing, and the improvement in minimizing pressure drop. Upstream mixer 1106 may be configured such that upstream blades 1108 are disposed symmetrically or asymmetrically about upstream blade hub 1109.

The first flow device 206 comprises a downstream mixer 309 (see fig. 2), the downstream mixer 309 comprising a downstream blade 310. It should be understood that the downstream mixer 309 shown and described with reference to fig. 2 may be included in any of the embodiments of the blade vortex mixer 200 discussed herein.

The downstream blades 310 are attached to a downstream blade hub 313, which downstream blade hub 313 is not radially offset from the central axis of the blade vortex mixer 200. However, downstream blade hub 313 may alternatively deviate within the following ranges:

0≤HD _{deviation from} ≤0.25d _V (5)

Wherein d is _V Is venturi diameter and HD _{Deviation from} Is the radial offset of the downstream vane hub center relative to the venturi central axis, the downstream vane hub center and the venturi central axis are each radially offset from the mixer central axis, as shown in fig. 3. Radial deflection HD of downstream blade hub _{Deviation from} May be radially offset from the upstream blade hub HD _{Deviation from} With the same amount and the same radial direction, the offset of the downstream blade hub can also be independent of the offset of the upstream blade hub. This deviation again creates variable geometry vanes, since the radial distance from the downstream vane hub to the venturi body varies depending on the radial direction. Downstream blade hub 313 is coupled to venturi body 302 (e.g., via components spaced adjacent to downstream blade 310, etc.). The downstream blade 310 may be similar to or different from the upstream blade 1108. The tip (e.g., outermost surface, etc.) of each of the downstream vanes 310 may be spaced from the venturi body 302 by an air gap such that the exhaust gases are dischargedThe body may pass between the tip of each of the downstream vanes 310 and the venturi body 302.

Downstream mixer 309 includes a plurality of downstream blade apertures spaced between a plurality of downstream blades 310. As such, the plurality of upstream vanes and the plurality of downstream vane apertures provide a swirling flow within the first flow device 206. Downstream vanes 310 are attached to the venturi body 302 and conform to the venturi body 302 such that exhaust gas can only exit the venturi body 302 through the downstream vane apertures. The plurality of upstream vane apertures cooperate with the plurality of downstream vanes 310 to provide a swirling flow to the exhaust gas entering the first flow device 206 that facilitates mixing of the reductant and the exhaust gas. The downstream blade 310 may be configured to generate a vortex flow (e.g., a co-vortex flow, a counter-vortex flow, etc.) that is separate from the vortex flow generated by the upstream blade 1108. In this way, the downstream vanes 310 may be used to increase or decrease the overall swirl generated by the first flow device 206. Further, the downstream vanes 310 may increase mixing of the reductant and exhaust gas within the venturi body 302.

In the embodiment shown in FIG. 2, the upstream vanes 1108 are located upstream of where the reductant is introduced, while the downstream vanes 310 are located downstream of where the reductant is introduced. In this embodiment, the upstream blade 1108 generates a first vortex flow in a first direction and the downstream blade 310 generates a second vortex flow in a second direction that is the same as (e.g., co-vortex flow, etc.) or opposite (e.g., anti-vortex flow, etc.) to the first direction. Rather than the upstream vanes 1108 confining the exhaust gas flow in a single path to create a swirling flow, several openings are provided between adjacent upstream vanes 1108 such that each of the upstream vanes 1108 independently swirls the exhaust gas and such that the upstream vanes 1108 collectively create a swirling flow in the exhaust gas.

In various applications, the upstream blade 1108 and/or the downstream blade 310 may be constructed (e.g., fabricated, manufactured, etc.) using sheet metal (e.g., aluminum sheet, steel sheet, etc.). For example, the upstream blade 1108 and/or the downstream blade 310 may be configured by stamping, punching, laser cutting, water jet cutting, bending, and/or welding operations.

FIG. 3 shows an example of a vortex mixer blade having a different geometry. The blade hub has been moved in the direction of the blade edge of blade V1, creating blade 1108 in which the length of the blade edge increases from blade edge length L1 to blade edge length L4 (counterclockwise movement). The vanes V4 are also bent at a greater angle than V1, V2 and V3, thereby forming a larger opening and allowing a greater proportion of the total flow to pass. This is depicted in fig. 3 by the plus sign "+" (indicating a smaller blade opening angle) at the gaps between V4 and V5 and the minus sign "-" (indicating a larger blade opening angle) at the gaps between the blades V1 and V2, the blades V2 and V3, and the blades V3 and V4, respectively. The blade angle of each of the blades of the blade vortex mixer may be different.

FIG. 3 illustrates a combined upstream blade 1700 in one embodiment. Combined upstream vane 1700 may be formed in various ways. In various embodiments, combined upstream blade 1700 is formed from a large upstream blade 1108, which large upstream blade 1108 is folded flat (e.g., at a blade angle of 90 degrees, etc.). In these embodiments, the large upstream blade 1108 may be twice the size of the other upstream blades 1108. In other embodiments, combined upstream vane 1700 is formed from a first upstream vane V5 and a second adjacent and contiguous upstream vane V6. In these embodiments, the first and second adjacent upstream blades V5 and V6 each have a blade angle of 90 degrees, and then the first and second adjacent upstream blades V5 and V6 are directly joined (e.g., adjacent edges of the first and second adjacent upstream blades V5 and V6 are attached together, respectively, etc.) or indirectly joined (e.g., spanning members (spans) are attached to each of the first and second adjacent upstream blades V5 and V6, respectively, etc.).

The blade edges may also be at an angle γ with the dispenser injection axis 215 directed toward the center of the venturi, the angle γ being defined between the dispenser injection axis 215 and the circumferentially nearest radial edge of the blade. The angle γ may be between ± 360 °/2n, where n is the number of vanes (including vanes that open and close). In the embodiment illustrated in figure 3, the angle γ is defined between the dispenser injection axis 215 and the edge of the vane V5 closest to the dispenser injection axis. In a blade vortex mixer with n =6, the angle γ may be between-30 degrees (counterclockwise in fig. 3) and +30 degrees (clockwise in fig. 3), as depicted in fig. 3. For ease of calculation, the combined blade may always be considered as a single closed blade, similar to the blades V5 and V6 depicted in fig. 3.

FIG. 4 shows a cross-sectional view of a vane vortex mixer 200. The upstream mixer 1106 is located upstream of the exhaust gas directing bore 306 (see also fig. 2) and the first flow device 206 is located downstream of the exhaust gas directing bore 306. Upstream mixer 1106 functions to generate a swirling flow of exhaust gas within first flow device 206 downstream of upstream mixer 1106. The swirling flow created by the upstream mixer 1106 facilitates distribution of the reductant in the exhaust gas between the upstream mixer 1106 and the downstream vanes 310 such that the reductant is substantially equally distributed in the exhaust gas as the exhaust gas encounters the downstream vanes 310. Further, the swirling flow generated by the upstream mixer 1106 generates relatively large shear forces at the venturi body 302 (e.g., the portion of the venturi body 302 between the upstream blade 1108 and the downstream blade 310, etc.) to reduce the formation of a film along the venturi body 302, and thus reduce the accumulation of deposits. The downstream vanes 310 act to impart a swirling flow on the exhaust gas and entrained reductant downstream of the first flow device 206. This swirling flow causes the exhaust gas to be relatively uniform (e.g., in terms of reductant composition, etc.) downstream of the first flow device 206, such as at the vane swirl mixer outlet 204 (e.g., adjacent the inlet of the SCR catalyst 106, etc.).

The venturi body 302 is defined by a body central axis A _V And (4) limiting. The venturi body 302 has a body central axis A _V Is centered (e.g., the center of mass (centroid) of the venturi body 302 and the body central axis A _V Overlapping, etc.). Upstream vane hub 1109 is offset from axis h _r As the center. As can be seen in fig. 3, off-axis h _r Radial deflection HU of _{Deviation from} So that is atAny reductant accumulated on the venturi body 302 (e.g., uneven distribution of reductant in the exhaust gas within the first flow device 206, etc.) is substantially redistributed into the exhaust gas downstream of the first flow device 206. Albeit offset from the axis h _r From the central axis A of the venturi _V Deviating from port 216 by the radial deviation HU of FIG. 4 _{Deviation from} However, it should be understood that the offset axis h _r May be taken from the venturi central axis A _V Deviating radially from HU toward port 216 _{Deviation from} Or from the venturi central axis A _V The radial offset HU is offset in any radial direction (e.g., orthogonal to the port 216, at an angle to the dispenser) toward the venturi body 302 _{Deviation from} 。

The venturi body 302 has a body inlet 1304 and a body outlet 1306. The inlet has a diameter d _V And the outlet has a diameter d _S Diameter d of d _S Generally smaller than the diameter d _V . Diameter d _V And diameter d _S Are all smaller than the diameter D of the blade vortex mixer 200 ₀ . In various embodiments, blade vortex mixer 200 and first flow device 206 are configured such that:

0.4D ₀ ≤d _V ≤0.9D ₀ (6)

0.7d _V ≤d _S ≤d _V (7)

0≤h _r ≤0.1D ₀ (8)

in various embodiments, the first support flange 304 does not protrude into the venturi body 302 (e.g., the first support flange 304 defines a bore adjacent to the venturi body 302, and the first support flange 304 has a diameter d equal to _S Diameter of (d), etc.).

In various embodiments, the funneled rim 300 protrudes radially from the body inlet 1304 toward the blade vortex mixer 200 by a distance h _i . In various embodiments, the first flow device 206 is configured such that:

0≤h _i ≤0.1d _V (9)

by varying the distance h _i Can be optimized into a first flow setThe exhaust gas flows through the nozzle 206 and/or the exhaust gas guide holes 306.

The reductant flows from the port 216 through the exhaust gas directing bore 306. The exhaust gas guide holes 306 are generally circular and have a diameter d _e And (4) limiting. In various embodiments, the first flow device 206 is configured such that:

wherein

5°≤δ≤20° (11)

Where δ is a margin selected based on the configuration of the first flow device 206, and where α is the spray angle of the nozzle directing the flow of the exhaust gas. In some embodiments, the exhaust gas guiding bore 306 is oval-shaped. In these embodiments, the diameter d _e May be the major axis (e.g., opposite the minor axis, etc.) of the exhaust gas guide holes 306.

The first flow device 206 is further defined by the spacing L between the upstream mixer 1106 and the downstream mixer 309 _h And (5) limiting. Interval L _h May be a fixed distance between the upstream mixer and the downstream mixer independent of the diameter D of the blade vortex mixer 200 ₀ And inlet diameter d _V Or the outlet diameter d _S . This allows a wide range of scaling options for the mixer diameter while keeping the overall length of the blade vortex mixer 200 to a minimum. Previous exhaust gas mixers have not been able to scale the diameter of the exhaust gas mixer independently of the mixer length. This allows the diameter of the exhaust gas mixer to be increased without increasing the length required to fit the vane swirl mixer within the exhaust unit. Diameter D of vane vortex mixer 200 ₀ And venturi entrance diameter d _V May vary based on space requirements and performance goals of the application. Diameter D of vane vortex mixer 200 ₀ May be in the range of 8 inches (20.32 cm) to 15 inches (38.1 cm) with the venturi inlet diameter d _V May be in the range of 2 inches (5.08 cm) to 13.5 inches (34.29 cm) while maintaining the spacing L _h Constant。

In various embodiments, the first flow device 206 is configured such that:

the venturi body 302 includes a shroud 1308. It should be understood that the shroud 1308 shown and described with reference to FIG. 4 may be included in any of the embodiments of the vane vortex mixer 200 discussed herein.

The shroud 1308 defines the downstream end of the venturi body 302, and thus is defined by a diameter d _S And (4) limiting. In various embodiments, the shroud 1308 is cylindrical or conical (e.g., frustoconical, etc.) in shape. The shroud 1308 may help reduce stratification of the exhaust gases caused by centrifugal forces generated by the downstream mixer 309. Further, the shroud 1308 may provide structural support to the downstream mixer 309, such as when the downstream blades 310 and the downstream blade hub 313 are attached to the shroud 1308 (e.g., such that the downstream blades 310 conform to the shroud 1308, etc.). When the downstream blades 310 are attached to the shroud 1308, the downstream blades 310 may provide a more directional swirling flow (e.g., along a target trajectory, etc.) by removing the leakage path, thereby improving mixing performance (e.g., the ability of the downstream mixer 309 to mix the reductant and exhaust gases, etc.) and reducing the accumulation of deposits downstream of the downstream mixer 309 (e.g., in the shroud 1308, in exhaust components downstream of the blade swirl mixer 200, etc.). In addition, the shroud 1308 substantially prevents leakage flow and liquid film accumulation and mitigates the formation of deposits within the first flow device 206 (e.g., on the venturi body 302, etc.) and/or the vane vortex mixer 200. Shroud 1308 is formed with a center axis A that is parallel to the venturi _V And the axis of the mixer central axis. In various embodiments, the first flow device 206 is configured such that:

Φ≤50° (13)

in various embodiments, the first flow device 206 is configured such that:

wherein L is _S Is the length of the shroud 1308. Where the shroud 1308 is cylindrical, the diameter d _S Is equal to the diameter d _v And is

0.02d _v ≤L _S ≤0.25d _v (15)

In some embodiments, at least one of the flow devices of the vane vortex mixer 200 is angled with respect to the mixer central axis. For example, the first flow device 206 may be configured such that the venturi central axis a _V Inclined upwardly from the mixer central axis (e.g., at a positive angle with respect to the mixer central axis, etc.), or such that the venturi central axis a _V Downwardly from the mixer central axis (e.g., at a negative angle relative to the mixer central axis, etc.).

The upstream vanes 1108 may be spaced apart from the venturi body 302 by a gap g. In various embodiments, the first flow device 206 is configured such that:

0≤g≤0.15d _V (16)

the gap g may mitigate the accumulation of reductant deposits on the venturi body 302. The gap g acts to create a substantially axial exhaust gas flow directed along the venturi body 302 (e.g., on an inner surface of the venturi body 302, etc.). In this way, the gap g may balance the flow of exhaust gas (e.g., primarily tangential flow, etc.) through the upstream vanes 1108 with the aforementioned axial flow and exhaust gas flow around the first flow device 206. Instead of or in addition to the gap g, the upstream vanes 1108 may include slots (e.g., thin slots) or orifices through which exhaust gas may flow. For example, each of the upstream blades 1108 may include a slot that abuts an outermost edge of the upstream blade 1108. In this example, exhaust gas may flow through the slot and abut the venturi body 302 adjacent the slot, providing benefits similar to the gap g.

In FIG. 4, the downstream blades 310 are shown in contact with the shroud 1308 such that there is no gap between at least a portion of each of the downstream blades 310 and the shroud 1308. In the exemplary embodiment, a tip (e.g., a most radially outward surface, etc.) of each of downstream blades 310 is welded (e.g., fused, etc.) to shroud 1308.

In some embodiments, the downstream blades 310 may be spaced apart from the shroud 1308 by a gap g _v . In various embodiments, the first flow device 206 is configured such that:

0≤g _v ≤0.15d _V (17)

gap g _v Accumulation of reductant droplets on the shield 1308 may be mitigated. Gap g _v Acts to produce a substantially axial flow of exhaust gas directed along the shroud 1308 (e.g., on an inner surface of the shroud 1308, etc.). Instead of the gap g _v Or except for the gap g _v In addition, the downstream vanes 310 may include slots (e.g., thin slots) or apertures through which exhaust gas may flow. For example, each of the downstream blades 310 may include a slot adjacent to an outermost edge of the downstream blade 310. In this example, the exhaust gas may flow through the slots and abut the shroud 1308 adjacent the slots, providing benefits similar to those of the gap g.

In some embodiments, the tip of each of the upstream vanes 1108 is attached (e.g., welded, coupled, etc.) to the venturi body 302 (e.g., such that the upstream vanes 1108 conform to the venturi body 302, etc.). When the upstream vane 1108 is attached to the venturi body 302, the upstream vane 1108 may provide a more directional swirling flow (e.g., along a target trajectory, etc.) by removing the leakage path, thereby improving mixing performance (e.g., the ability of the upstream mixer 1106 to mix the reductant and the exhaust gas, etc.) and reducing the accumulation of deposits downstream of the upstream mixer 1106 (e.g., in the venturi body 302, on the downstream mixer 309, downstream of the vane swirl mixer 200, etc.). In fig. 4, the upstream vanes 1108 are shown in contact with the venturi body 302 such that there is no gap between at least a portion of each of the upstream vanes 1108 and the venturi body 302.

Each of the upstream blades 1108 is defined by an upstream blade angle relative to an upstream blade hub center axis of an upstream blade hub 1109 of the upstream blade 1108. Similarly, the downstream blade angle of each of the downstream blades 310 is defined relative to the downstream blade hub central axis of the downstream blade hub 313. The upstream blade angle of each of the upstream blades 1108 may be different from the upstream blade angle of any other upstream blade 1108. In various embodiments, the upstream blade angle of each of the upstream blades 1108 is between forty-five and ninety degrees (including forty-five and ninety degrees) relative to the downstream blade hub center axis of the downstream blade hub 313, and the downstream blade angle of each of the downstream blades 310 is between forty-five and ninety degrees (including forty-five and ninety degrees). The upstream vane angle of each of the upstream vanes 1108 may be selected such that the first flow device 206 is customized for a target application. Similarly, the downstream blade angle of each of the downstream blades 310 may be selected such that the first flow device 206 is customized for the target application. The upstream mixer 1106 may be configured such that the upstream blades 1108 are symmetrically or asymmetrically disposed about the upstream blade hub 1109.

The upstream vane angle may be different for each of the upstream vanes 1108 and the downstream vane angle may be different for each of the downstream vanes 310. The upstream blade angle of each of the upstream blades 1108 and the downstream blade angle of each of the downstream blades 310 may be selected so as to generate an asymmetric vortex of the exhaust gas to direct the flow of the exhaust gas (e.g., toward a target location in the blade vortex mixer 200, etc.), to more evenly distribute the reductant in the exhaust gas, and to reduce deposits in the first flow device 206 (e.g., on the venturi body 302, etc.) and/or the blade vortex mixer 200.

FIG. 5 illustrates the exhaust gas flow within the vane vortex mixer 200 and illustrates how the exhaust gas behaves as it encounters the first flow device 206. The exhaust gas upstream of first flow device 206 is divided into a primary flow 1900 (e.g., venturi flow, vortex flow, etc.) and a circuitous flow 1902 (e.g., exhaust gas secondary flow, etc.). The primary flow 1900 is provided into the first flow device 206 (e.g., the primary flow 1900 is funneled into the venturi body 302 by the funnel edge 300, etc.).

In some embodiments, the bypass flow 1902 is 5% -40% (including 5% and 40%) of the sum (e.g., total flow, etc.) of the bypass flow 1902 and the primary flow 1900. In these embodiments, the primary flow 1900 is 60% -95% (including 60% -95%) of the sum (e.g., total flow, etc.) of the bypass flow 1902 and the primary flow 1900. Thus, where the blade vortex mixer 200 includes six upstream blades 1108, each gap between adjacent upstream blades 1108 receives 6% -16% (including 6% -16%) of the sum (e.g., total flow, etc.) of the bypass flow 1902 and the primary flow 1900.

The main flow 1900 and the bypass flow 1902 define a split ratio. The split ratio is the ratio of the bypass flow 1902 to the primary flow 1900, expressed as a percentage of the primary flow 1900. The split ratio being the diameter d _V Diameter d of _e And a distance h _i Is measured as a function of (c). By varying the split ratio, optimization of a target mixing performance (e.g., based on computational fluid dynamics analysis, etc.), a target deposit formation amount (e.g., a target amount of deposits formed over a target time period, etc.), and a target pressure drop (e.g., a comparison of exhaust gas pressure upstream of first flow device 206 and exhaust gas pressure downstream of first flow device 206, etc.) of first flow device 206 may be performed, such that first flow device 206 may be customized for a target application. In various embodiments, the split ratio is between five percent and seventy percent (including five percent and seventy percent). That is, bypass flow 1902 is between five percent and seventy percent (including five percent and seventy percent) of primary flow 1900.

The bypass flow 1902 is divided into a diverted flow 1904 and an isolated flow 1906. Diverted stream 1904 mixes with the reductant provided to first flow device 206 through port 216. For example, the bypass flow 1902 may pass directly through the exhaust gas guiding bore 306 into the venturi body 302 as a diverted flow 1904.

Isolation flow 1906 does not immediately enter first flow device 206, but encounters first support flange 304. In various embodiments, first support flange 304 seals against vane vortex mixer 200 and venturi body 302 and does not allow barrier flow 1906 to pass through or around first support flange 304. In these embodiments, the barrier flow 1906 flows back toward the body inlet 1304. As the isolation flow 1906 flows back toward the body inlet 1304, a portion of the isolation flow 1906 may flow into the venturi body 302 as a diverted flow 1904. Other portions of the barrier flow 1906 may flow through the exhaust gas pilot bore 306 and enter the venturi body 302 through the body inlet 1304 as the primary flow 1900. In other embodiments, first support flange 304 includes at least one aperture that allows exhaust gas to pass through, thereby allowing at least a portion of barrier flow 1906 to completely bypass the body. This portion of the barrier flow 1906 will mix with the primary flow 1900 downstream of the body outlet 1306 (e.g., after the primary flow 1900 has been combined with the diverted flow 1904 and reductant within the venturi body 302, etc.).

According to the embodiment shown in FIG. 5, the primary flow 1900 passes through the upstream blades 1108, mixes with the reductant and the diverted flow 1904, and then passes through the downstream blades 310, through the shroud 1308, and exits the body outlet 1306.

Fig. 6 shows a second support flange 2100 according to an example embodiment. It should be understood that the second support flange 2100 shown and described with reference to fig. 6 may be included in any embodiment of the vane vortex mixer 200 discussed herein. The second support flange may be coupled to the venturi body upstream of the exhaust gas guide bore 306, as shown in fig. 6, which fig. 6 illustrates a view of the upstream face of the first flow device 206. The second support flange 2100 may also be coupled to the venturi body 302 downstream of the exhaust gas guide bore 306 but upstream of the first support flange 304. The second support flange 2100 may also be coupled to the venturi body 302 upstream of the exhaust gas guiding bore 306. In some embodiments, the second support flange 2100 abuts the funnel edge 300 (e.g., the funnel edge 300 is part of the second support flange 2100, etc.).

Second support flange 2100 includes a plurality of second support flange apertures 2102 (e.g., apertures, channels, pathways, etc.). Bypass flow 1902 passes through second support flange aperture 2102 to pass through second support flange 2100. In various embodiments, the second support flange 2100 can include one, two, three, four, five, six, or more second support flange apertures 2102.

Each of second support flange apertures 2102 is separated from an adjacent one of second support flange apertures 2102 by a second support flange connector 2104 (e.g., an arm, a bar, etc.). The second support flange connector 2104 is integrated with the second support flange 2100 and is coupled to the blade vortex mixer 200 and the first flow device 206. In one example, the second support flange connector 2104 is coupled to the venturi body 302 and the first support flange 304 is coupled to the shroud 1308. In some embodiments, the second support flange 2100 is coupled to the funnel edge 300 (e.g., the funnel edge 300 is part of the second support flange 2100, etc.).

The second support flange 2100 does not protrude into the body inlet 1304 (e.g., the second support flange 2100 defines a bore adjacent to the venturi body 302 and has a diameter equal to d _V Diameter, etc.). In various embodiments, the second support flange 2100 includes one, two, three, four, five, six, or more second support flange connectors 2104. In some embodiments, the number of second support flange apertures 2102 is equal to the number of second support flange connectors 2104.

In this embodiment, the dispenser 214 is aligned with the center of the venturi. The dispenser 214 may also be aligned with the offset upstream hub 1109 or the downstream hub 313. Alternatively, the dispenser 214 may be aligned with the venturi axis, however the dispenser nozzle may direct the flow of reducing agent toward the offset upstream hub center 1109 and corresponding axis h _r And (5) guiding.

Second support flange apertures 2102 are distributed around the circumference of venturi body 302. In this embodiment, the largest second support flange aperture 2102 is twice the size of the other four second support flange apertures 2102 and is arranged such that bypass flow 1902 is directed unimpeded toward dispenser 214 and exhaust gas guide aperture 306. To this end, the largest second support flange aperture 2102 may further preferably be circumferentially centered about the dispenser injection axis 215. Alternatively, second support flange aperture 2102 is arranged such that no second support flange connector 2104 is positioned upstream of dispenser 214 and vent guide aperture 306 in the direction of bypass flow 1902.

Fig. 7A and 7B illustrate a conduit straight blade mixer 2200 according to an example embodiment. It should be understood that the conduit straight blade mixer 2200 as shown and described with reference to fig. 7A and 7B may be included in any of the embodiments of the blade vortex mixer 200 discussed herein.

Catheter straight blade mixer 2200 includes a plurality of catheter straight blades 2202, each catheter straight blade 2202 coupled to and conforming to a catheter straight blade hub 2206. Any conduit straight blade 2202 and any combination conduit straight blade form a conduit between them, rather than forming a hole between any conduit straight blade 2202 as it does between adjacent upstream blades 1108. As explained herein, a conduit is a closed path (e.g., bounded on four of six sides, etc.) with a single inlet and a single outlet.

Although not shown, an end (e.g., outermost edge, etc.) of each of the conduit straight vanes 2202 is coupled to the shroud 1308 or the venturi body 302 and conforms to the shroud 1308 or the venturi body 302. The trailing edge of one of the straight duct blades 2202 or the combined straight duct blades flows in the flow direction S _t Extend upwardly beyond the leading edge of the adjacent one of the duct straight vanes 2202 or the combined duct straight vanes, thereby restricting exhaust gas flow to a span wise direction (S) _P The above. Direction of flow S _t Tangential to the plane of the straight blades of the duct at the tip of the leading edge, and in a spanwise direction S _P Orthogonal (e.g., perpendicular, etc.) to the flow direction S relative to the plane of the straight blade at the leading edge tip of the conduit _t . This spanwise restriction, combined with the conformal coupling of the conduit straight blades 2202 with the conduit straight blade hub 2206 and with the shroud 1308 (both restricting flow in the wall normal direction), creates a conduit for each of the conduit straight blades 2202. Each conduit has four sides: a first side defined by one catheter straight blade 2202 or a combined catheter straight blade, a second side defined by a catheter straight blade hub 2206A third side defined by the shroud 1308 or venturi body 302, a fourth side defined by another conduit straight vane 2202 or a combination conduit straight vane. Each conduit effectively directs exhaust gases. In various embodiments, the conduit straight blade mixer 2200 is used in the first flow device 206 in place of the downstream mixer 309. In other embodiments, the conduit straight blades 2202 are not coupled to the shroud 1308, but are coupled to the venturi body 302 and conform to the venturi body 302. In these embodiments, the conduit straight vane 2202 is instead coupled to the venturi body 302 and conforms to the venturi body 302. In such embodiments, the conduit straight blade mixer 2200 may be used in place of the upstream mixer 1106 or as an adjunct to the upstream mixer 1106.

In some embodiments, the conduit straight blade mixer 2200 includes two, three, four, five, six, seven, eight, or more spaced conduit straight blades 2202. Like the upstream vanes 1108, each of the conduit straight vanes 2202 is defined by a vane angle. These blade angles may be varied so that a combined duct straight blade (not shown) may be formed as described above with respect to combined upstream blade 1700. In some embodiments, the conduit straight blade mixer 2200 includes one, two, three, or more combination conduit blades. In other embodiments, the conduit straight blade mixer 2200 does not include a combination conduit blade. In the exemplary embodiment, conduit straight blade mixer 2200 includes three conduit straight blades 2202 and one combined conduit straight blade.

Catheter straight blade hub 2206 is offset from mixer central axis by HU _{Deviation from} As described above.

Each of the straight duct blades 2202 and combined straight duct blades extend above the adjacent straight duct blade 2202 or combined straight duct blade. This distance is shown in FIG. 7A as extending distance E _sw . Extend a distance E _sw Expressed as being off-axis (e.g., venturi central axis A) _V Mixer central axis, etc.) of the flow direction S of a single duct straight blade 2202 at a given distance _t On the catheter straight blade hub 2206 is centered on the axis. In various embodiments, theExtend a distance E _sw Is the direction of flow S of a single duct straight blade 2202 at a given distance from the axis _t Between 0% and 75% (including 0% and 75%) of the width of catheter straight blade hub 2206 centered on the axis. Extend a distance E _sw May be different for each of the individual conduit straight blades 2202 (e.g., one conduit straight blade 2202 has an extension distance E of 25%) _sw Adjacent duct straight vanes 2202 having an extension distance E of 40% _sw The other duct straight blade 2202 has an extension distance E of 75% _sw )。

The conduit straight blade mixer 2200 provides a relatively high swirl velocity even at lower blade angles of each of the conduit straight blades 2202, thereby providing enhanced mixing of the reductant with a lower pressure drop. Another benefit of the high swirl velocity provided by the conduit straight blades 2202 and the combined conduit straight blades is that the high swirl velocity mitigates the accumulation of deposits downstream of the conduit straight blade mixer 2200 (e.g., along the venturi body 302, along the shroud 1308, etc.).

Each of the straight duct blade 2202 and the combined straight duct blade extends from a flow direction angle ℃ _sa The catheter straight blade hub 2206 is defined to be centered on this axis. In various embodiments, the flow direction angle ℃ _sa Between thirty and ninety degrees (including thirty and ninety degrees). Flow direction angle ℃ &ofeach of the straight duct blade 2202 and the straight duct blade combination _sa May be selected such that the first streaming device 206 is customized for the target application.

For each of the straight duct blade 2202 and/or the combined straight duct blade, the angle of flow ∈ _sa And a flow direction extension distance E _sw May be different. The flow direction angle ∈ for each of the selected straight conduit blades 2202 and/or combined straight conduit blades may be selected _sa And a flow direction extension distance E _sw To generate an asymmetric swirling flow of exhaust gas, to direct the flow of exhaust gas (e.g., toward a target location in the vane swirl mixer 200, etc.), to more evenly distribute reductant in the exhaust gas, and/or to reduce the first flow device 206 (e.g., on the venturi body 302, etc.) and/or the vane swirl mixer200, in the sample.

The conduit straight blade 2202 and/or the combined conduit straight blade may be constructed using casting (e.g., investment casting, lost foam casting, sand casting, etc.) and/or 3D printing. For example, the conduit straight blade mixer 2200 may use a 3D printer by using a specified number of conduit straight blades 2202, a number of combined conduit straight blades, a flow direction angle ∈ for each of the conduit straight blades 2202 and the combined conduit straight blades _sa And a flow direction extension distance E of each of the conduit straight blade 2202 and the combined conduit straight blade _sw To print.

FIG. 8 illustrates a curved blade mixer 2300, according to an example embodiment. It should be understood that the curved blade mixer 2300 shown and described with reference to FIG. 8 may be included in any of the embodiments of the blade vortex mixer 200 discussed herein.

In various embodiments, a curved blade mixer 2300 is utilized in the first flow device 206 in place of the upstream mixer 1106 or the downstream mixer 309.

The curved blade mixer 2300 includes a plurality of curved blades 2302 and a combined curved blade 2304. In some embodiments, curved blade mixer 2300 includes two, three, four, five, six, seven, eight, or more curved blades 2302. In some embodiments, the curved blade mixer 2300 includes one, two, three, or more combined curved blades 2304. In other embodiments, the curved blade mixer 2300 does not include the combined curved blades 2304. In the exemplary embodiment, curved blade mixer 2300 includes three curved blades 2302 and one combined curved blade 2304.

Each of the curved blades 2302 and the combined curved blades 2304 are attached to a curved blade hub 2306, the curved blade hub 2306 being offset from the mixer centerline axis by HU _{Deviation from} As described above. Curved blades 2302 and/or combined curved blades 2304 may be arranged symmetrically or asymmetrically about curved blade hub 2306. Similar to catheter straight blade 2202, each of curved blade 2302 and combined curved blade 2304 may overlap. Each of curved blades 2302 and combined curved blades 2304 is adjacent curved blade 2302 or combined curved bladeExtending over blade 2304 by an extension distance E as described herein _sw 。

The curved blades 2302 and the combined curved blades 2304 have a curved or aerodynamic shape that reduces the pressure drop of the exhaust gases and promotes a more even distribution of the flow downstream of the curved blade mixer 2300, such as along the central axis of the curved blade mixer 2300.

Each curved blade 2302 is defined by a curved blade angle α relative to a curved blade hub centerline axis of the curved blade hub 2306 _CV And (5) limiting. Similarly, the combined curved blade 2304 may be defined by a curved blade angle α relative to a curved blade hub centerline axis of the curved blade hub 2306 _CV To define. The curved blade angle α is due to the curved nature of the curved blade 2302 and the combined curved blade 2304 _CV Is variable. The curved blade angle of each of the curved blade 2302 and the combined curved blade 2304 may be different from the curved blade angle α of the other

curved blades

2302 and 2304 _CV 。

Curved blades 2302 and/or combined curved blades 2304 may be constructed using casting and/or 3D printing. For example, the curved blade mixer 2300 may use a 3D printer by specifying the number of curved blades 2302, the number of combined curved blades 2304, and the curved blade angle α of each of the curved blades 2302 and the combined curved blades 2304 using a 3D printer _CV To print. In various embodiments, the curved vanes 2302 and/or the combined curved vanes 2304 may be designed to keep the tangential angle constant at each point along the curved vanes 2302 or the combined curved vanes 2304 or to minimize the aerodynamic drag on each curved vane 2302 or the combined curved vane 2304. In one embodiment, a 3D printed or cast curved blade 2303 may be inserted into the venturi body 302 and welded to the first support flange 304.

Fig. 9 and 10 illustrate a shrouded blade mixer 3100 in accordance with example embodiments. It should be understood that the shrouded blade mixer 3100 shown and described with reference to fig. 9 and 10 may be included in any of the embodiments of the multi-stage mixer 200 discussed herein.

Fig. 10 is a cross-sectional view of the shrouded blade mixer 3100. In various embodiments, a shrouded blade mixer 3100 is utilized in place of the upstream mixer 1106 or the downstream mixer 309 in the first flow device 206.

The shrouded blade mixer 3100 includes a plurality of shrouded blades 3102 and a combined shrouded blade 3104. In some embodiments, the shrouded blade mixer 3100 comprises two, three, four, five, six, seven, eight, or more shrouded blades 3102. In some embodiments, the shrouded blade mixer 3100 comprises one, two, three, or more combined shrouded blades 3104. In other embodiments, the shrouded blade mixer 3100 does not include the composite shrouded blade 3104. In the exemplary embodiment, the shrouded blade mixer 3100 includes three shrouded blades 3102 and one combined shrouded blade 3104.

Each of shrouded blades 3102 and combined shrouded blades 3104 are attached to a shrouded blade hub 3106, which shrouded blade hub 3106 is offset from the central axis of the blade vortex mixer by HU _{Deviation from} As described above. Shrouded blades 3102 and/or combined shrouded blades 3104 may be arranged symmetrically or asymmetrically about a shrouded blade central hub 3106. Each of shrouded blade 3102 and combined shrouded blade 3104 may overlap, similar to conduit straight blade 2202.

The shrouded blade mixer 3100 includes a recess 3108. When shrouded vane mixer 3100 is installed in vane vortex mixer 200, recess 3108 is configured to fit around exhaust guide hole 306.

The shrouded bucket mixer 3100 combines the functionality of a mixer (e.g., upstream mixer 1106, downstream mixer 309, etc.) and the functionality of a shroud (e.g., shroud 1308, etc.) in a single component. In this way, the shrouded vane mixer 3100 may reduce costs (e.g., manufacturing costs, etc.) and manufacturing complexity of the vane vortex mixer 200. Additionally, combining the mixer and shroud in a single component, the shrouded blade mixer 3100 reduces manufacturing tolerances in the blade angle of the shrouded blade 3102, thereby reducing variability between different shrouded blade mixers 3100. The thickness of each of the shrouded blades 3102 may be constant or variable throughout the shrouded blade 3102, for example vertically along the shrouded blade 3102 or horizontally along the shrouded blade 3102. In various embodiments, the shrouded blade 3102 has a thickness between 1.5 millimeters and 6 millimeters (including 1.5 millimeters and 6 millimeters). Similarly, in various embodiments, the edge of each of the shrouded blades 3102 has a radius between 0.5 mm and 3 mm (including 0.5 mm and 3 mm). This radius may reduce flow separation of the exhaust gases, mitigate accumulation of reductant deposits, and reduce stress concentrations on the shrouded blades 3102 and/or the shroud 1318.

Fig. 11 shows a comparison of the normalized pressure drop (normalized pressure drop), flow uniformity index (flow uniformity index) and reductant uniformity index (reductant uniformity index) of the vane vortex mixer according to the embodiments shown in fig. 2 to 4 and described above, as determined via Computational Fluid Dynamics (CFD) calculations, with previous designs of vane vortex mixers detailed in WO 2018/226626 A1, where the mixer lengths of the two variants are the same. It can be seen that the improved design of the angled vanes with different lengths and/or angles results in improved uniformity of exhaust gas flow and reductant at the catalyst inlet downstream of the mixer, and a reduction in pressure drop at the exhaust gas guide holes. The reduced pressure drop is associated with a reduced exhaust swirl velocity, which is beneficial in reducing the likelihood of catalyst erosion. Additional flow devices may also be included downstream of the vane vortex mixer and upstream of the flow-through or wall-flow catalyst to further improve flow distribution. These flow devices may be perforated plates or similar devices having a predetermined open area.

Construction of the example embodiment

While this specification contains many specific implementation details, these should not be construed as limitations on the scope of what may be claimed, but rather as descriptions of features specific to particular implementations. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable subcombination. Moreover, although features may be described as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a subcombination or variation of a subcombination.

As utilized herein, the terms "substantially," "approximately," and similar terms are intended to have a broad meaning consistent with the commonly accepted usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. Those skilled in the art who review this disclosure will appreciate that these terms are intended to allow description of certain features described and claimed without limiting the scope of these features to the precise numerical ranges provided. Accordingly, these terms should be interpreted as indicating that insubstantial or inconsequential modifications or variations of the subject matter described and claimed are considered to be within the scope of the invention as recited in the appended claims.

The terms "coupled," "connected," and the like as used herein mean that two components are directly or indirectly joined to one another. Such joining may be fixed (e.g., permanent) or movable (e.g., removable or releasable). Such joining may be achieved with the two members or the two members and any additional intermediate members being integrally formed as a single unitary body with one another or with the two members or the two members and any additional intermediate members being attached to one another.

As used herein, the terms "fluidly coupled," "in fluid communication," and the like, mean that two components or objects have a path formed therebetween in which a fluid (such as exhaust gas, water, air, a gaseous reducing agent, gaseous ammonia, and the like) may flow with or without intervening components or objects. Examples of fluid couplings or configurations capable of fluid communication may include pipes, channels, or any other suitable components capable of flowing a fluid from one component or object to another. As described herein, "preventing" should be construed as potentially allowing minimal bypass (e.g., less than 1%) of the exhaust gas.

It should be understood that some features may not be necessary and embodiments lacking the same may be contemplated as within the scope of the application, the scope being defined by the claims that follow. When the language "a portion" is used, the item can include a portion and/or the entire item unless specifically stated to the contrary.

Claims

1. A vane vortex mixer for exhaust aftertreatment, the vane vortex mixer centered about a mixer central axis, the vane vortex mixer comprising:

a vane vortex mixer inlet configured to receive exhaust gas;

a vane vortex mixer outlet configured to provide the exhaust gas to a catalyst;

a plurality of upstream vane apertures spaced between the plurality of upstream vanes, the plurality of upstream vane apertures configured to receive the exhaust gas and cooperate with the plurality of upstream vanes to provide a swirling flow to the exhaust gas that promotes mixing of the reductant and the exhaust gas;

a plurality of downstream vane apertures spaced between the plurality of downstream vanes, the plurality of downstream vane apertures configured to receive the exhaust gas and cooperate with the plurality of downstream vanes to facilitate further mixing of the reductant and the exhaust gas;

wherein at least one of the upstream blade hub and the downstream blade hub is radially offset from the venturi central axis, thereby differing a geometry of each of the plurality of upstream blades coupled to the radially offset upstream blade hub and/or differing a geometry of each of the plurality of downstream blades coupled to the radially offset downstream blade hub.

2. The blade vortex mixer of claim 1 wherein the downstream blade hub is centered about the venturi central axis.

3. The vane vortex mixer of claim 1 or 2 wherein:

each of the plurality of upstream blades is defined by an upstream blade angle between an upstream blade hub central axis of the upstream blade hub and a plane of an upstream blade, the upstream blade hub central axis being parallel to the venturi central axis;

the upstream blade angle of each of the plurality of upstream blades is between forty-five and ninety degrees, including forty-five and ninety degrees.

4. The vane vortex mixer of claim 3 wherein the upstream vane angle of one of the plurality of upstream vanes is different than the upstream vane angle of another one of the plurality of upstream vanes.

5. The vane vortex mixer of claim 2 wherein:

each of the plurality of downstream blades is defined by a downstream blade angle between a downstream blade hub central axis of the downstream blade hub and a plane of a downstream blade, the downstream blade hub central axis being parallel to the venturi central axis;

the downstream blade angle of each of the plurality of downstream blades is between forty-five and ninety degrees, including forty-five and ninety degrees.

6. The blade vortex mixer of claim 3 wherein:

the downstream vane angle of each of the plurality of downstream vanes is between forty-five and ninety degrees, including forty-five and ninety degrees.

7. The blade vortex mixer of claim 4 wherein:

each of the plurality of downstream blades is defined by a downstream blade hub center axis of the downstream blade hub and a downstream blade plane, the downstream blade hub center axis being parallel to the venturi center axis;

8. The vane vortex mixer of any one of claims 5-7 wherein the downstream vane angle of one of the plurality of downstream vanes is different than the downstream vane angle of another one of the plurality of downstream vanes.

9. The vane vortex mixer of any one of claims 1-2 and 4-7, wherein each of the plurality of upstream vanes and at least one of each of the plurality of downstream vanes are coupled to and conform with the venturi body such that each of the coupled and conforming vanes cooperates with the venturi body to form a conduit.

10. The vane vortex mixer of claim 3 wherein each of the plurality of upstream vanes and at least one of each of the plurality of downstream vanes are coupled to and conform with the venturi body such that each of the coupled and conforming vanes cooperates with the venturi body to form a conduit.

11. The vane vortex mixer of claim 8 wherein each of the plurality of upstream vanes and at least one of each of the plurality of downstream vanes are coupled to and conform with the venturi body such that each of the coupled and conforming vanes cooperates with the venturi body to form a conduit.

12. The vane vortex mixer of claim 1 or 2 wherein:

at least one of the plurality of upstream vanes and the plurality of downstream vanes is a duct straight vane, wherein:

a flow direction angle is defined between the flow direction and a hub central axis of a catheter straight vane hub, the hub central axis of the catheter straight vane hub being parallel to the venturi central axis;

the flow direction angle of each of the plurality of conduit straight vanes is between thirty and ninety degrees, including thirty and ninety degrees.

13. The vane vortex mixer of claim 12 wherein the flow direction angle of one of the plurality of duct straight vanes is different than the flow direction angle of another one of the plurality of duct straight vanes.

14. The vane vortex mixer of claim 12 wherein:

each of the plurality of conduit straight vanes is coupled to and conforms with the venturi body such that each of the plurality of conduit straight vanes cooperates with the venturi body to form a conduit.

15. The vane vortex mixer of claim 13 wherein:

16. The vane vortex mixer of claim 12 wherein:

said one of said plurality of duct straight vanes having a width in said flow direction; and is provided with

The extension distance is between zero percent and seventy-five percent, including seventy-five percent, of the width in the flow direction of the one of the plurality of duct straight vanes.

17. The vane vortex mixer of any one of claims 13-15 wherein:

one of the plurality of conduit straight vanes extends an extension distance above another of the plurality of conduit straight vanes;

18. The blade vortex mixer of any one of claims 1-2, 4-7, 10-11, and 13-16 wherein:

the venturi body includes an exhaust gas guide hole disposed along the venturi body between the body inlet and the body outlet.

19. The vane vortex mixer of claim 18 wherein

The discharge gas guide hole is one of circular and elliptical.

20. The blade vortex mixer of any one of claims 1-2, 4-7, 10-11, 13-16, and 19, further comprising a reducing agent dispenser for introducing the reducing agent into the blade vortex mixer along a reducing agent introduction axis.

21. The blade vortex mixer of claim 20 wherein:

the angle (gamma) between the reductant introduction axis and the circumferentially nearest radial edge of the vane will be at

Where n is the number of blades.

22. A vane vortex mixer according to claim 20 when dependent on claim 18 wherein:

the reductant dispenser is positioned around the exhaust gas guide aperture.

23. The vane vortex mixer of claim 22 wherein:

the reductant dispenser and the exhaust gas directing holes are positioned on a vertical mid-plane of the blade vortex mixer to direct the reductant toward the mixer central axis.

24. The vane vortex mixer of claim 22 wherein:

the reductant dispenser and the exhaust gas directing apertures are positioned offset from a vertical mid-plane of the blade vortex mixer to direct the reductant toward the venturi wall.

25. The blade vortex mixer of any one of claims 1-2, 4-7, 10-11, 13-16, 19, 21-24 wherein:

the venturi central axis is radially offset from the mixer central axis.

26. A diesel exhaust unit comprising a flow-through catalyst or a wall-flow catalyst and a vane vortex mixer according to any of claims 1-25.