Apparatus, system, and method for mixing a flow

Abstract

A mixer comprises an inner pipe defining a first flow path and an inlet zone including a first opening proximate a first end of the inner pipe in fluid communication with the first flow path. An outer pipe circumscribes the inner pipe and defines a second flow path between an outer surface of the inner pipe and an inner surface of the outer pipe. The inlet zone further includes a second opening in fluid communication with the second flow path. A baffle includes a boss in engagement with the inner surface of the outer tube. The boss has a distal end positioned within the outer tube and proximate to and spaced apart from the second end of the inner tube. An outlet zone is positioned at a second end of the inner pipe where the first flow path and the second flow path interconnect and mix.

Description

Attorney Docket No. 2001 U-001866-WO-POAAPPARATUS, SYSTEM, AND METHOD FOR MIXING A FLOWField of the invention

[0001] The present invention relates to a device, system, and method for mixing a flow, in particular for mixing an exhaust gas flow from, for example, an internal combustion engine.Background of the invention

[0002] Mixers are used in a variety of technical applications to produce homogeneous mixtures. Homogeneous mixtures of, for example, reactants enable ideal reactions and thus, for example, reduced pollutant emissions. Mixers can be used, for example, for exhaust gas aftertreatment, in particular in conjunction with catalytic converters. Catalytic converters generally function ideally under homogeneous conditions, such as a homogeneous concentration of reactants and / or a homogeneous temperature. Mixers in exhaust gas streams can enable a more even distribution of the reactants in the reaction path and thus a more efficient conversion of the reactants into products. Mixers can be used, for example, to reduce emissions of pollutants such as carbon monoxide (CO) and / or nitrogen oxide (NOx).

[0003] Another technical application concerns the regeneration of diesel particulate filters. Soot particles accumulate in diesel particulate filters and must be removed regularly through controlled combustion. To carry out regeneration effectively and ensure or increase the service life of the filter, an even temperature distribution is required. Mixers can help to keep the temperature of an exhaust gas stream homogeneous, which can prevent damage to the diesel particulate filter and improve its regeneration.

[0004] Mixers can generally be used in combustion systems to enable a homogeneous composition and thus stable and efficient combustion processes. Mixing the reactants can, for example, facilitate complete combustion, which increases efficiency and reduces emissions at the same time. The use of mixers contributes, for example, to compliance with emission regulations, optionally in conjunction with injected cleaning additives such as ammonia NH3 and / or urea as ammonia formers in selectiveAttorney Docket No. 2001 U-001866-WO-POA catalytic reduction systems. These systems serve to effectively reduce nitrogen oxides by enabling a uniform reaction between the exhaust gases and one or more additives.

[0005] In addition, mixers are used, for example, in laboratories where precise, stable, and / or homogeneous mixing ratios are required. Such mixing ratios are needed, for example, to calibrate instruments.

[0006] The functioning of a mixer is usually based on the use of special geometries, flow channels, or turbulence-generating elements such as baffles. These can promote mixing, minimizing fluctuations in temperature and concentration within the resulting gas flow.

[0007] US 201 1 / 061 374 A1 discloses an exhaust gas treatment system having an exhaust gas duct. Exhaust gas from an internal combustion engine can flow through the exhaust gas duct. The exhaust gas treatment system further comprises a selective catalytic reduction catalyst in the exhaust gas duct, a mixing chamber, a fuel injection valve for injecting fuel, an air injection valve for injecting air, and a urea water injection valve for injecting urea water. The fuel injection valve, the air injection valve, and the urea water injection valve each have an injection opening directed toward the mixing chamber. However, an annular baffle is not disclosed, but rather a plate that spans the entire crosssection. The exhaust gas duct is closed in the axial direction.

[0008] DE 10 2020 212 715 A1 discloses a heating device for heating an exhaust gas catalyst. The heating device comprises a combustion chamber; an air supply designed to feed air into the combustion chamber; a fuel injection device designed to inject fuel into the combustion chamber; an ignition device designed to ignite the fuel introduced into the combustion chamber; and a gas outlet designed to discharge hot combustion gases from the combustion chamber. A baffle is arranged in the gas outlet, comprising an outer, substantially closed region and an inner, substantially open region arranged within the outer region. The outer region extends along an outer periphery of the gas outlet and hinders or prevents the escape of unburned fuel through an outer region of the gas outlet. The open inner area allows combustion gases to flow out of the combustion chamber. A combination of mixing pipes for mixing two separate flows, e.g., inner and outer flows, is not disclosed.Attorney Docket No. 2001 U-001866-WO-POA

[0009] US 8 916 101 B2 discloses a device for mixing an aqueous reducing agent solution for addition thereof to an exhaust gas. The device is arranged between a filter that captures particulate substances contained in the exhaust gas and a reduction catalyst that reduces and treats nitrogen oxides in the exhaust gas. The device comprises an exhaust pipe; an injector; a mixing pipe having a plurality of openings on its outer peripheral surface; and an inner pipe that is spaced apart from and simultaneously arranged at a distance from an inner wall of the straight section, wherein the inner pipe allows the exhaust gas to flow through its inner side and its outer periphery. However, a combination of mixing pipes for mixing two separate flows, e.g., inner and outer flows, is not disclosed.

[0010] EP 2 607 641 A1 discloses a mixing device having an inner pipe. The inner pipe has openings through which an exhaust gas stream flows into the interior of the inner pipe. An injection unit injects a reducing agent into the interior of the inner pipe. A guide device arranged on the outer circumference of the inner pipe protrudes into the space in such a way that a circumferential flow enters radially through the openings. However, a combination of mixing pipes for mixing two separate flows, e.g., inner and outer flows, is not disclosed.

[0011] Furthermore, DE 1 1 2015 001 958 T5 discloses an exhaust gas aftertreatment system for a vehicle and an exhaust gas aftertreatment system comprising a perforated mixing pipe having a swirl body. The mixing pipe is arranged in an exhaust pipe and comprises a tubular section and a plurality of wings extending from a longitudinal end of the tubular section. The tubular section comprises a plurality of openings extending through an inner and an outer diametrical surface of the tubular section. The tubular section and the plurality of blades define a uniform, integrally formed body.

[0012] Existing mixers often cannot completely prevent local concentration fluctuations of, for example, ammonia NH3 or urea in selective catalytic reduction systems, for example due to the geometry of the surrounding system and / or during a cold start or generally in a low-load and / or low-temperature range, where injected reactants can form droplets and make mixing difficult. It may therefore be desirable to furtherAttorney Docket No. 2001 U-001866-WO-POA improve the mixing of a stream. In particular, it may be desirable to improve mixing in conventional mixers via short paths, for example, to enable shorter flow channels and / or to enable mixing independently of the surrounding system. It may also be desirable to improve production processes in order to provide a mixer with improved mixing without increasing the cost of the mixer.Object of the invention

[0013] The objective of the present invention is to overcome the disadvantages described above and, in particular, to provide devices, systems, and methods for mixing a flow that enable improved mixing of the flow while keeping the cost of the mixer low.Summary of the invention

[0014] The above-mentioned object and further problems are solved by devices, systems, and methods having the features of the independent claims.

[0015] Preferred embodiments are the subject of the respective dependent claims.

[0016] According to a first aspect, the invention relates to a mixer for mixing a flow in a treatment system, comprising: an inlet zone having: one or more first openings configured to generate a flow within an inner pipe; and one or more second openings configured to generate a flow between an inner pipe and an outer pipe; the inner pipe; and the outer pipe comprising an outlet zone configured to generate a local turbulent flow according to the treatment system. This allows, for example, for an improved mixing to be achieved.

[0017] According to a further development, the outlet zone comprises a first baffle; and / or the outlet zone comprises a second baffle. This allows further vortices to be formed, which further increase mixing.

[0018] According to a further development, the outlet zone comprises one or more first mixing blades; and / or the outlet zone comprises one or more second mixing blades. Mixing blades can break up strands in the flow path with widely varying concentrations of reactants and cause a mixing with strands of other concentrations. The mixing blades thus lead to homogenization of the concentration distribution in the flow path.Attorney Docket No. 2001 U-001866-WO-POA

[0019] According to a further development, the one or more first mixing blades are arranged in a plane perpendicular to the direction of flow directly on the outer pipe or on the first baffle; and / or the one or more second mixing blades are arranged in a plane perpendicular to the direction of flow directly on the outer pipe or on the second baffle.

[0020] According to a further development, the one or more first mixing blades are arranged asymmetrically; and / or the one or more second mixing blades are arranged asymmetrically. The asymmetrical arrangement may relate to a symmetry element of a symmetry group of the mixer or a component thereof, such as the inner or outer pipe. Symmetry element and symmetry group are to be understood in the classical, mathematical sense. Symmetrical arrangements of the first mixing blades and / or the second mixing blades are also possible, for example, depending on the geometry of the treatment system.

[0021] According to a further development, the first baffle is formed as a separate component or it is formed integrally from the outer pipe; and / or the second baffle is formed as a separate component or it is formed integrally from the outer pipe; and / or the first baffle and / or the second baffle is formed as a separate counterpart to the outer pipe, which can be mounted on the outer pipe in a form-fitting manner.

[0022] According to a further development, the one or more second mixing blades are formed integrally from the outer pipe.

[0023] According to a further development, the number of the first mixing blades is smaller than the number of the second mixing blades. The number of the first mixing blades may also be equal to or greater than the number of the second mixing blades.

[0024] According to a second aspect, the invention relates to a system comprising: a device that generates a flow; a control for reducing pollutant emissions by injecting a reactant into the flow by means of an injection device in a treatment system; and the treatment system comprising a mixer as described above.Attorney Docket No. 2001 U-001866-WO-POA

[0025] According to a third aspect, the invention relates to a method for reducing pollutant emissions from a flow of a device that generates the flow, comprising: arranging a mixer according to the present invention in a treatment system; adapting the outlet zone of the mixer to the treatment system.Brief description of the drawings

[0026] The invention and further details and advantages thereof are explained below with reference to preferred embodiments and the figures. They show:

[0027] Fig. 1 is a side view of a mixer in a treatment system having an injection device, three different outlet zones, and two further components of the treatment system according to an exemplary embodiment;

[0028] Fig. 2A is a side view of an outlet zone having baffles according to an exemplary embodiment with baffles;

[0029] Fig. 2B is a side view of a region of the outlet zone shown in Fig. 2A having baffles according to an exemplary embodiment;

[0030] Fig. 3 is a perspective side view of a mixer in a treatment system having an injection device and two further components of the treatment system according to an exemplary embodiment;

[0031] Fig. 4A is a side view of an outlet zone having baffles according to an exemplary embodiment with baffles;

[0032] Fig. 4B is a side view of a region of the outlet zone shown in Fig. 4A having baffles according to an exemplary embodiment;

[0033] Fig. 5A is a perspective side view of a region of an outlet zone having a first baffle according to an exemplary embodiment;

[0034] Fig. 5B is a perspective side view of a region of an outlet zone having first mixing vanes according to an exemplary embodiment;

[0035] Fig. 6A is a perspective side view of a region of an outlet zone having a second baffle according to an exemplary embodiment;

[0036] Fig. 6B is a perspective side view of a region of an outlet zone having second mixing blades according to an exemplary embodiment;

[0037] Fig. 7 depicts a system comprising a device that generates a flow, a controller for reducing pollutant emissions from the flow, and a treatment system comprising a device for mixing the flow with reactants; andAttorney Docket No. 2001 U-001866-WO-POA

[0038] Fig. 8 shows a method for reducing pollutant emissions from a flow of a device that generates the flow.

[0039] In all figures, identical or functionally identical elements and devices are designated by the same reference numerals. The numbering of process steps serves for reasons of clarity and does not generally imply a specific chronological order. In particular, several process steps may also be carried out simultaneously.Detailed description of the invention

[0040] In the present description, the terms above, below, right, and left, as well as similar terms, refer to the orientations or arrangements shown in the figures and serve only to describe the embodiments. These terms may indicate preferred arrangements, but are not to be understood in a limiting sense.

[0041] Furthermore, the terms "essentially," "approximately," "about", and similar terms mean that deviations of + / -10%, preferably + / -5%, from the stated value are permissible.

[0042] Unless explicitly excluded, the ranges of values mentioned herein are always understood to mean that lower limits are included with ">" (greater than or equal to) and upper limits are included with "<" (less than or equal to) in the specified range of values. Thus, in particular, the limits themselves are either included in the respective range or, alternatively, may be excluded (on one side).

[0043] Fig. 1 shows a side view of a mixer 1000 in a treatment system comprising an injection device, four different outlet zones 1420A, 1420B, 1420C, and 1420D, and two further components of the treatment system according to an exemplary embodiment. The mixer 1000 may also be embedded in another system that is suitable for passing a flow through the mixer 1000.

[0044] The mixer 1000 comprises an inlet zone 1200, an inner pipe 1300, and an outer pipe 1400 having an outlet zone. The mixer 1000 may have an optional coupling zone 1 100 for coupling with an injection device. Alternatively or additionally, the outer pipe 1400 may be configured for coupling with the treatment system. The inner pipe 1300Attorney Docket No. 2001 U-001866-WO-POA and the outer pipe 1400 may be coupled to each other, e.g., by means of brackets between the inner pipe 1300 and the outer pipe 1400.

[0045] The injection device may be a device for injecting reactants such as oxygen, air, fuel, urea, ammonia, etc. The injection device may have one or more valves for injecting one reactant at a time. The injected substances may form droplets during injection. Depending on the size of the droplets and the temperature of the treatment system, the injected substances may evaporate more or less quickly. The substances may also be injected in gaseous form.

[0046] The inlet zone 1200 may have one or more first openings. The one or more first openings may be configured to generate one or more flows in the inner pipe 1300, e.g., swirling flows, circular flows, and / or turbulent flows. Alternatively or additionally, the inlet zone 1200 may comprise one or more second openings. The one or more second openings may be configured to generate a flow between the inner pipe 1300 and the outer pipe 1400, e.g., swirling flows, circular flows, and / or laminar flows. The second openings may be formed by the concentric arrangement of the inner pipe 1300 and the outer pipe 1400.

[0047] The inner pipe 1300 may have the shape of a cylinder, a cone, or any other shape suitable for generating a flow in the inner pipe 1300. A cross-section of the inner pipe 1300 in a plane (e.g., the yz - plane in Fig. 1 ) perpendicular to the direction (e.g., the x - direction in Fig. 1 ) of the flow may, during operation, have the shape of a circle, an ellipse, an irregular or regular polygon with, for example, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , or more corners, or an irregular or regular loop with or without corners. The cross-section of the inner pipe 1300 may vary along a flow path perpendicular to the direction of flow. The inner pipe 1300 may be curved once or multiple times in the direction of flow.

[0048] The inner pipe 1300 may be straight, single-curved or multi-curved in a main flow direction, e.g. to make use of available installation space and / or with regard to the mixing behavior of the mixer 1000.

[0049] The diameter of a cross-section can be in the range between 30 and 300 millimeters (mm), preferably in the range between 50 and 150 mm, e.g., 60 mm.Attorney Docket No. 2001 U-001866-WO-POA

[0050] The inlet zone 1200 can be formed in one piece or in several pieces together with the inner pipe 1300. The one or more first openings can, for example, be formed on a one-piece pipe. The one or more first openings can have at least one of a wing angled relative to a surface of the pipe or a hole. The first openings can be punched or drilled. The optional coupling zone 1 100 may also be formed in one piece or in several pieces together with the inner pipe 1300. In particular, the coupling zone 1100, the inlet zone 1200, and the inner pipe 1300 may be formed in one piece.

[0051] The outer pipe 1400 may have the shape of a cylinder, a cone, or any other shape suitable for generating a flow between the inner pipe 1300 and the outer pipe 1400. The flow between the inner pipe 1300 and the outer pipe 1400, also known as mantle flow, may have a heating effect that transfers heat to the inner pipe 1300.

[0052] A cross-section of the outer pipe 1400 in a plane (e.g., the yz - plane in Fig. 1 ) perpendicular to the direction (e.g., the x - direction in Fig. 1 ) of the flow can, during operation, have the shape of a circle, an ellipse, an irregular or regular polygon with, for example, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , or more corners, or an irregular or regular loop with or without corners. The cross-section of the outer pipe 1400 may vary along a flow path perpendicular to the direction of flow. The outer pipe 1400 may be curved once or multiple times in the direction of flow.

[0053] The inner pipe 1300 and the outer pipe 1400 may have the same shape in a region along the flow path perpendicular to the direction of flow, wherein a distance between the inner pipe 1300 and the outer pipe 1400 in the region is identical for each cross-section. The distance may also be different for different cross-sections in the area. The distance may be in the range between 1 and 20 mm, preferably in the range between 5 and 15 mm, and even more preferably in the range between 7 and 12 mm. The shapes of the inner pipe 1300 and of the outer pipe 1400 may also be different in the region along the flow path. The inner pipe 1300 and the outer pipe 1400 may be curved once or several times in the direction of flow.

[0054] A ratio of a cross-sectional area between the inner pipe 1300 and the outer pipe 1400 relative to a cross-sectional area of the inner pipe 1300 may be between 5:95Attorney Docket No. 2001 U-001866-WO-POA and 60:30, preferably between 10:90 and 30:70. The ratio may be adjustable, i.e., the mixer 1000 may be configured to adjust the ratio.

[0055] Inner pipe 1300 includes a first end 1302 and an opposite second end 1304. A first flow path Fi extends through inner pipe 1300. Inlet zone 1200 includes one or more first openings 1306 extending therethrough. First openings 1306 place an inner volume 1308 of inner pipe 1300 in fluid communication with a volume of gas 1310 positioned outside of the inner pipe 1300. Inner pipe 1300 includes an outer surface 1312.

[0056] Outer pipe 1400 includes a first end 1402 and an opposite second end 1404. Outer pipe 1400 circumscribes inner pipe 1300 defining a gap 1406 therebetween. Inlet zone 1200 includes a second opening 1408 that places gap 1406 in fluid communication with gas volume 1310 to define a second flow path F2. Outer tube 1400 includes an inner surface 1410 that along with outer surface 1312 at least partially defines second flow path F2. The second flow path F2 may also be identified as a bypass flow path. Gas flow through the bypass flow path is not treated with injected reagent (if present) but this flow serves to desirably heat inner pipe 1300 that will, at times, contain a mixture of injected reagent and exhaust gas.

[0057] Outlet zone 1420 is positioned at second end 1304 of inner pipe 1300 and second end 1404 of second pipe 1400 where first flow path F1 and second flow path F2 intermix. Outlet zone 1420 includes a baffle 1500 as best depicted with reference to outlet zone 1420C shown in Fig. 1. Baffle 1500 includes a body portion 1502 and a boss 1504. Boss 1504 includes a tubular sidewall 1506 extending from body portion 1502 inwardly toward second end 1304. Tubular sidewall 1506 engages inner surface 1410 of outer tube 1400 and supports second end 1404 of outer tube 1400. Boss 1504 further includes a radially inwardly extending portion 1508 positioned at a distal end 1510 of boss 1504. An aperture 1512 extends through boss 1504. Radially inwardly extending portion 1508 circumscribes aperture 1512.

[0058] The outer pipe 1400 comprises an outlet zone 1420, which is described in detail below with reference to Figs. 2A and 2B. The outlet zone 1420 may be designed in different ways, as shown by four different exemplary outlet zones 1420A, 1420B,Attorney Docket No. 2001 U-001866-WO-POA1420C, and 1402D. The exemplary outlet zones 1420A, 1420B, 1420C, and 1420D may be combined with each other.

[0059] Outlet zone 1420D shown in Fig. 1 depicts a baffle 1550 including alternate geometry to support outer tube 1400 while providing a radially inwardly extending portion 1558 to perform the turbulence generating function.

[0060] Fig. 2A shows a side view of an outlet zone 2420 comprising baffles according to an exemplary embodiment. The outlet zone 2420 is part of a mixer 2000, shown only in part, having an inner pipe 2300 and an outer pipe 2400. The mixer 2000 is similar to mixer 1000 of Fig. 1. Fig. 2B shows an enlarged region of the outlet zone 2420 shown in Fig. 2A.

[0061] The outer pipe 2400 comprises an outer pipe wall 2410 and an outlet zone 2420. The inner pipe 2300 comprises an inner pipe wall 2310. The inner pipe 2300 conducts substances such as droplets and / or gases between the inner pipe wall 2310 and the outer pipe wall 2410 with a flow into the outlet zone 2420. The interior of the inner pipe 2300 conducts substances such as droplets and / or gases having a flow to the outlet zone. In the direction of flow, the inner pipe 2300 is shorter than the outer pipe 2400. In the opposite direction, the inner pipe 2300 may be longer than the outer pipe 2400. The outlet zone 2420 is configured to generate a locally enhanced turbulent flow in order to cause additional mixing, at least locally.

[0062] A distance between one end of the inner pipe 2300 in the outlet zone 2420 and one end of the outer pipe 2400 in the outlet zone 2420, e.g. at the first baffle 2421 , can be in a range between 2 and 50 mm, preferably in the range between 5 and 35 mm, more preferably in the range between 7 and 20 mm. The outlet zone 2420 can correspond to said range.

[0063] In the side view, the outlet zone 2420 may comprise a first baffle 2421 . The first baffle 2421 may essentially be a projection which extends along a circumferential direction in a plane (e.g., the yz - plane in Fig. 1 ) into the interior of the outer pipe 2400. The first baffle 2421 may form an angle with respect to the outer pipe wall 2410 in the range between 15 and 165°, preferably in the range between 35° and 155°, and moreAttorney Docket No. 2001 U-001866-WO-POA preferably in the range between 55° and 135°. The first baffle 2421 may be a separate component. The separate component may be welded, soldered, or riveted to the outer pipe wall 2410. Other fastening means are also possible, such as gluing. The first baffle 2421 may also be formed integrally from the outer pipe 2400, for example by pressing and / or rolling a groove or by upsetting the outer pipe 2400.

[0064] The first baffle 2421 can have a height in the range between 1 and 20 mm, preferably in the range between 5 and 15 mm, and even more preferably in the range between 7 and 12 mm, relative to the outer pipe wall 2410. The height can be smaller than, equal to, or greater than the distance between the inner pipe 1300 and the outer pipe 1400.

[0065] Alternatively or additionally, the outlet zone 2420 may comprise a second baffle 2426. The second baffle 2426 may essentially be a projection which extends from the end of the outer pipe 2400 along a circumferential direction in a plane into the interior of the outer pipe 2400 in order to engage the flow during operation. The second baffle 2426 may form an angle with respect to the outer pipe wall 2410 in the range between 15 and 165°, preferably in the range between 35° and 155°, and more preferably in the range between 55° and 135°. The second baffle 2421 may be a separate component. The separate component may be welded, soldered, or riveted to the end of the outer pipe wall 2410. Other fastening means are also possible, such as gluing. The second baffle 2421 may also be formed integrally from the outer pipe 2400, for example by pressing and / or rolling the end of the outer pipe wall 2410.

[0066] The second baffle 2426 can have a height in the range between 1 and 20 mm, preferably in the range between 5 and 15 mm, and even more preferably in the range between 7 and 12 mm, relative to the outer pipe wall 2410. The height can be smaller than, equal to, or greater than the distance between the inner pipe 2300 and the outer pipe 2400.

[0067] The height of the first baffle 2421 and the height of the second baffle 2426 may be the same or different. In particular, the height of the second baffle 2426 may be greater than the height of the first baffle 2421 .Attorney Docket No. 2001 U-001866-WO-POA

[0068] The first baffle 2421 and / or the second baffle 2426 may be configured to produce a secondary mixing effect, complementary to the primary mixing effect which is due to the flow inside the inner pipe 2300.

[0069] It should be appreciated that Fig. 1 includes embodiment 1420C depicting baffle 1500. Baffle 1500 may also be described as an alternate embodiment second baffle in view of the description pertaining to Fig. 2A. Fig. 1 does not show a first baffle radially inwardly projecting from inner tube 1300 but includes radially inwardly extending portion 1508 positioned at a distal end 1510 of boss 1504 to perform the mixing function of the second baffle described above.

[0070] Fig. 3 shows a side view of a mixer 3000 in a treatment system comprising an injection device and two further components of the treatment system according to an exemplary embodiment. The mixer 3000 may also be embedded in another system which is suitable for passing a flow through the mixer 3000.

[0071] The mixer 3000 comprises an inlet zone 3200, an inner pipe 3300, and an outer pipe 3400 having an outlet zone. The mixer 3000 may have an optional coupling zone 3100 for coupling with an injection device. Alternatively or additionally, the outer pipe 3400 may be configured for coupling with the treatment system. The inner pipe 3300 and the outer pipe 3400 may be coupled to each other, for example by means of brackets between the inner pipe 3300 and the outer pipe 3400.

[0072] The injection device may be a device for injecting reactants such as oxygen, air, fuel, urea, ammonia, etc. The injection device may have one or more valves for injecting one reactant at a time.

[0073] The inlet zone 3200 may have one or more first openings. The one or more first openings may be configured to generate one or more flows in the inner pipe 3300, e.g., swirling flows, circular flows, and / or turbulent flows. Alternatively or additionally, the inlet zone 3200 may have one or more second openings. The one or more second openings may be configured to generate a flow between the inner pipe 3300 and the outer pipe 3400, e.g., swirling flows, circular flows, and / or laminar flows. The second openings may be formed by the concentric arrangement of the inner pipe 3300 and the outer pipe 3400.Attorney Docket No. 2001 U-001866-WO-POA

[0074] The inner pipe 3300 may have the shape of a cylinder, a cone, or any other shape suitable for generating a flow in the inner pipe 3300. A cross-section of the inner pipe 3300 in a plane (e.g., the yz - plane in Fig. 3) perpendicular to the direction (e.g., the x - direction in Fig. 3) of the flow may, during operation, have the shape of a circle, an ellipse, an irregular or regular polygon with, for example, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , or more corners, or an irregular or regular loop with or without corners. The cross-section of the inner pipe 3300 may vary along a flow path perpendicular to the direction of flow. The inner pipe 3300 may be curved once or multiple times in the direction of flow.

[0075] A diameter of a cross-section may lie in the range between 30 and 400 millimeters (mm), preferably in the range between 50 and 150 mm, e.g., 60 mm.

[0076] The inlet zone 3200 can be formed in one piece or in several pieces together with the inner pipe 3300. The one or more first openings can be formed, for example, on a one-piece pipe. The one or more first openings can have at least one wing or hole angled relative to a surface of the pipe. The first openings can be punched or drilled. The optional coupling zone 3100 may also be formed in one piece or in several pieces together with the inner pipe 3300. In particular, the coupling zone 3100, the inlet zone 3200, and the inner pipe 3300 may be formed in one piece.

[0077] The outer pipe 3400 may have the shape of a cylinder, a cone, or any other shape suitable for generating a flow between the inner pipe 3300 and the outer pipe 3400. The flow between the inner pipe 3300 and the outer pipe 3400, also referred to as mantle flow, can have a heating effect through which heat is transferred to the inner pipe 3300.

[0078] A cross-section of the outer pipe 3400 in a plane (e.g., the yz - plane in Fig. 3) perpendicular to the direction (e.g., the x - direction in Fig. 3) of the flow may, during operation, have the shape of a circle, an ellipse, an irregular or regular polygon with, for example, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , or more corners, or an irregular or regular loop with or without corners. The cross-section of the outer pipe 3400 may vary along a flow path perpendicular to the direction of flow. The outer pipe 3400 may be curved once or multiple times in the direction of flow.Attorney Docket No. 2001 U-001866-WO-POA

[0079] The inner pipe 3300 and the outer pipe 3400 may have the same shape in a region along the flow path perpendicular to the direction of flow, wherein a distance between the inner pipe 3300 and the outer pipe 3400 in said region is identical for each cross-section. The distance may also be different for different cross-sections in said region. The distance may be in the range between 1 and 20 mm, preferably in the range between 5 and 15 mm, and even more preferably in the range between 7 and 12 mm. The shapes of the inner pipe 3300 and the outer pipe 3400 may also be different in the region along the flow path. The inner pipe 3300 and the outer pipe 3400 may be curved once or several times in the direction of flow.

[0080] A ratio of a cross-sectional area between the inner pipe 2300 and the outer pipe 2400 relative to a cross-sectional area of the inner pipe 2400 may be between 5:95 and 60:30, preferably between 10:90 and 30:70. The ratio may be adjustable, i.e., the mixer 2000 may be configured to adjust the ratio.

[0081] The outer pipe 3400 comprises an outlet zone, which is described in detail below with reference to Figs. 4A and 4B.

[0082] Fig. 4A shows a side view of an outlet zone 4420 comprising baffles according to an exemplary embodiment. The outlet zone 4420 is part of a mixer 4000, shown only partially, having an inner pipe 4300 and an outer pipe 4400. The mixer 4000 is compatible with the mixer 3000 of Fig. 1 , Fig. 2A and Fig. 2B, and Fig. 3. Fig. 4B shows an enlarged region of the outlet zone 4420 shown in Fig. 4A.

[0083] The outer pipe 4400 comprises an outer pipe wall 4410 and an outlet zone 4420. The inner pipe 4300 comprises an inner pipe wall 4310. The inner pipe 4300 directs substances such as droplets and / or gases between the inner pipe wall 4310 and the outer pipe wall 4410, having a flow into the outlet zone 4420. The interior of the inner pipe 4300 conducts substances such as droplets and / or gases, having a flow to the outlet zone. In the direction of flow, the inner pipe 4300 is shorter than the outer pipe 4400. In the opposite direction, the inner pipe 4300 may be longer than the outer pipe 4400. The outlet zone 4420 is configured to generate a locally intensified turbulent flow in order to effect additional mixing, at least locally.Attorney Docket No. 2001 U-001866-WO-POA

[0084] A distance between one end of the inner pipe 4300 in the outlet zone 4420 and one end of the outer pipe 4400 in the outlet zone 4420, e.g. at the first baffle 4421 , can be in the range between 2 and 50 mm, preferably in the range between 5 and 35 mm, and even more preferably in the range between 7 and 20 mm. The outlet zone 4420 can correspond to the range.

[0085] In the side view, the outlet zone 4420 may comprise a first baffle 4421 . The first baffle 4421 may essentially be a projection which extends along a circumferential direction in a plane (e.g., the yz - plane in Fig. 3) into the interior of the outer pipe 4400. The first baffle 4421 may form an angle with respect to the outer pipe wall 4410 in the range between 15 and 165°, preferably in the range between 35° and 155°, and more preferably in the range between 55° and 135°. The first baffle 4421 may be a separate component. The separate component may be welded, soldered, and / or riveted to the outer pipe wall 4410. Other fastening means are also possible, such as gluing. The first baffle 4421 can also be formed integrally from the outer pipe 4400, for example by pressing and / or rolling a groove or by upsetting the outer pipe 4400.

[0086] The first baffle 4421 can have a height in the range between 1 and 20 mm, preferably in the range between 5 and 15 mm, and even more preferably in the range between 7 and 12 mm, relative to the outer pipe wall 4410. The height can be smaller than, equal to, or greater than the distance between the inner pipe 4300 and the outer pipe 4400.

[0087] Alternatively or additionally, the outlet zone 4420 may comprise a second baffle 4426 in the side view. The second baffle 4426 may essentially be a projection which extends from the end of the outer pipe 4400 along a circumferential direction in a plane into the interior of the outer pipe 4400 in order to engage the flow during operation. The second baffle 4426 may form an angle with respect to the outer pipe wall 4410 in the range between 15 and 165°, preferably in the range between 35° and 155°, and more preferably in the range between 55° and 135°. The second baffle 4421 may be a separate component. Said separate component may be welded, soldered, or riveted to the end of the outer pipe wall 4410. Other fastening means are also possible, such as gluing. TheAttorney Docket No. 2001 U-001866-WO-POA second baffle 4421 can also be formed integrally from the outer pipe 4400, for example by pressing and / or rolling the end of the outer pipe wall 4410.

[0088] The second baffle 4426 can have a height in the range between 1 and 20 mm, preferably in the range between 5 and 15 mm, and even more preferably in the range between 7 and 12 mm, relative to the outer pipe wall 4410. The height can be smaller than, equal to, or greater than the distance between the inner pipe 4300 and the outer pipe 4400.

[0089] The height of the first baffle 4421 and the height of the second baffle 4426 may be the same or different. In particular, the height of the second baffle 4426 may be greater than the height of the first baffle 4421 .

[0090] The first baffle 4421 and / or the second baffle 4426 may be configured to produce a secondary mixing effect, complementary to the primary mixing effect which is due to the flow inside the inner pipe 4300.

[0091] Fig. 5A shows a perspective side view of a region of an outlet zone having a first baffle 5421 according to an exemplary embodiment. The first orifice 5421 is formed on an outer pipe wall 5410, in a region between one end of the inner pipe wall 5310 and one end of the outer pipe wall 5410.

[0092] The first baffle 5421 may essentially be a projection extending along a circumferential direction in a plane (e.g., the yz - plane in Fig. 1 or Fig. 3) into the interior of the outer pipe 5400. The first baffle 5421 may form an angle with respect to the outer pipe wall 5410 in the range between 15 and 165°, preferably in the range between 35° and 155°, more preferably in the range between 55° and 135°. The angle may be exactly 90°.

[0093] The first baffle 5421 may be a separate component. The separate component may be welded, soldered, and / or riveted to the outer pipe wall 5410. Other fastening means are also possible, such as gluing. The first baffle 5421 can also be formed in one piece from the outer pipe 5400, e.g., by pressing and / or rolling a groove or by upsetting the outer pipe 5400.Attorney Docket No. 2001 U-001866-WO-POA

[0094] The first baffle 5421 may be the only baffle in the outlet zone. The first baffle 5421 may be arranged in a form-fitting manner directly at the end of the outer pipe wall 5410.

[0095] As shown in Fig. 5B, the outlet zone may further comprise one or more first mixing blades 5422, e.g., 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , or more first mixing blades 5422.

[0096] A first group of first mixing blades 5422 may be arranged in a first sector on the first baffle 5421 , while no first mixing blades 5422 or a second group of first mixing blades 5422 may be arranged in an adjacent sector on the first baffle 5421. The first mixing blades 5422 may be arranged specifically with reference to components of the treatment system that are located downstream in the flow path in order to reduce local concentration fluctuations. The position of the first mixing blades 5422 may be coordinated or may be adjustable with the components of the treatment system. The distance between directly adjacent first mixing blades 5422 on the first baffle 5421 may vary. The first mixing blades 5422 may be configured to be inclined relative to the first baffle 5421 , e.g., depending on the components of the treatment system.

[0097] The first mixing blades 5422 may be formed integrally with the first baffle 5421. The number of first mixing blades 5422 may be exactly identical to one of the above-mentioned numbers of first mixing blades 5422. It should be appreciated that baffle 1500 shown in Fig. 1 at 1420C may include similar mixing blades 1516, second baffle 2426 shown in Fig. 2B may include similar mixing blades 2427, and the second baffle 4426 shown in Fig. 4A may include mixing blades 4427.

[0098] Fig. 6A shows a perspective side view of a region of an outlet zone comprising a second baffle 6426 according to an exemplary embodiment. The second baffle 6426 is formed at one end of the outer pipe wall 6410.

[0099] The second baffle 6426 may essentially be a projection which extends from the end of the outer pipe along a circumferential direction in a plane into the interior of the outer pipe in order to engage the flow during operation. The second baffle 6426 may form an angle with respect to the outer pipe wall 6410 in the range between 15 and 165°,Attorney Docket No. 2001 U-001866-WO-POA preferably in the range between 35° and 155°, and more preferably in the range between 55° and 135°. The second baffle 6421 may be a separate component. Said separate component may be welded, soldered, or riveted to the end of the outer pipe wall 6410. Other fastening means are also possible, such as gluing. The second baffle 6421 can also be formed integrally from the outer pipe 6400, e.g., by pressing and / or rolling the end of the outer pipe wall 6410 and / or by drawing, i.e., by reducing a diameter by means of a forming tool coming from the outside, which locally reduces the diameter.

[0100] The second baffle 6426 can have a height in the range between 1 and 20 mm, preferably in the range between 5 and 15 mm, and even more preferably in the range between 7 and 12 mm, relative to the outer pipe wall 6410. The height can be smaller than, equal to, or greater than the distance between the inner pipe and the outer pipe.

[0101] The second baffle 6426 may be the only baffle in the outlet zone. The second baffle 6426 may be arranged in a form-fitting manner directly at the end of the outer pipe wall 6410.

[0102] As shown in Fig. 6B, the outlet zone may further comprise one or more second mixing blades 6427, e.g., 1 , 2, 3, 4, 5, 6, 7, 8, 9, 10, 1 1 , or more second mixing blades 6427.

[0103] A first group of second mixing blades 6427 may be arranged in a first sector on the second baffle 6426, while no second mixing blades 6427 or a second group of second mixing blades 6427 are arranged in an adjacent sector on the second baffle 6426. The second mixing blades 6427 may be arranged specifically with reference to components of the treatment system that are located downstream in the flow path in order to reduce local concentration fluctuations. The position of the second mixing blades 6427 may be coordinated or adjustable with the components of the treatment system. The distance between directly adjacent second mixing blades 6427 on the second baffle 6426 may vary. The second mixing blades 6427 may be configured to be inclined relative to the second baffle 6427, e.g., depending on the components of the treatment system.Attorney Docket No. 2001 U-001866-WO-POA

[0104] The second mixing blades 6427 may be formed integrally with the second baffle 6426. The number of second mixing blades 6427 may be exactly identical to one of the above-mentioned numbers of second mixing blades 6427.

[0105] First mixing blades 5422 and second mixing blades 6427 may be offset from each other in the circumferential direction in order to enhance a secondary mixing effect. The second mixing blades 6427 may be larger than the first mixing blades 5422. The number of first mixing blades 5422 may be smaller than the number of second mixing blades 6427. The second mixing blades may be larger or smaller than the first mixing blades, both in the radial and tangential directions (circumferential direction). The radial height of the mixing blades, or a length in the direction of the center of the inner pipe, may extend to a center of the inner pipe.

[0106] First mixing blades 5422 and / or second mixing blades 6427 may also be arranged on the outer pipe without a first baffle 5421 and / or without a second baffle 6426 in order to generate a local turbulent flow in accordance with the treatment system. In other words, first mixing blades 5422 and / or second mixing blades 6427 can be arranged so as to reduce local concentration fluctuations in the treatment system, e.g., due to its geometry. The arrangement of the mixing blades can thus be specific to the treatment system in which the mixer is inserted. Any of the embodiments described in this document may be equipped with mixing blades without departing from the scope of the disclosure. Other geometrical configurations for the blades are also contemplated. For example, some blades may be arranged at a regular or constant angular orientation while other blades may extend at different angles than other blades.

[0107] Fig. 7 shows a system 7000 comprising a device 7100 that generates a flow, a control 7200 for reducing pollutant emissions by the flow, and a treatment system 7300 comprising a device for mixing the flow with reactants as described above with reference to Figs. 1 to 6B.

[0108] Fig. 8 shows a method for reducing pollutant emissions from a stream of a device that generates the flow. A stream can also be referred to as a flow. The method comprises arranging 8100 a device for mixing the flow with reactants as described aboveAttorney Docket No. 2001 U-001866-WO-POA with reference to Fig. 1 to Fig. 6B in a treatment system, and adapting 8200 the outlet zone of the device for mixing the flow with reactants to the treatment system.

[0109] The methods, devices, and systems of the present disclosure may be used, for example, in light, medium, or heavy machinery, preferably in medium or heavy machinery such as trucks, tractors, harvesters, and construction machinery. Boat, ship, or rail applications are also possible.

[0110] The invention has been described on the basis of preferred embodiments, whereby the individual features of the described embodiments can be freely combined and / or exchanged with each other, provided they are compatible. Likewise, individual features of the described embodiments can be omitted if they are not absolutely necessary. Numerous modifications and designs are possible and obvious to the skilled person without departing from the inventive concept.Attorney Docket No. 2001 U-OQ1866-WO-POAList of reference signs:1000, 2000, 3000, 4000 Mixer1100, 3100 Coupling zone1200, 3200 Inlet zone 1300, 2300, 3300, 4300 Inner pipe1400, 2400, 3400, 4400, 5400, 6400 Outer pipe1420, 1420A, 1420B, 1420C, 1420D, 2420, 4420 Outlet zones2410, 4410, 5410, 6410 Outer pipe wall2310, 4310, 5310 Inner pipe wall 2421 , 4421 , 5421 First baffle2426, 4426, 6426 Second baffle5422, 6427 Mixing blade7000 System; 7100 Device; 7200 Control; 7300 Treatment system8100 Arrangement step; 8200 Adjustment step

Claims

Attorney Docket No. 2001 U-001866-WO-POAClaims1 . A mixer for mixing gas in a treatment system, the mixer comprising: an inner pipe including a first end, an opposite second end, and a first flow path extending therethrough; an inlet zone including at least one first opening proximate the first end, the at least one first opening placing a volume of gas external to the inner pipe in fluid communication an inner volume of the inner pipe along the first flow path; an outer pipe circumscribing the inner pipe and defining a second flow path between an outer surface of the inner pipe and an inner surface of the outer pipe, the inlet zone further including at least one second opening placing the volume of gas in fluid communication with the second flow path; a baffle including a boss in engagement with the inner surface of the outer tube, the boss having a distal end positioned within the outer tube as well as positioned proximate to and spaced apart from the second end of the inner tube; and an outlet zone positioned at the second end of the inner pipe where the first flow path and the second flow path interconnect to mix the gas exiting the first flow path and the second flow path, wherein the boss includes an aperture in receipt of the mixed gas.

2. The mixer according to claim 1 , wherein the boss of the baffle includes a tubular sidewall supporting the outer tube.

3. The mixer according to claim 2, wherein the baffle includes a radially inwardly extending portion at the distal end of the boss circumscribing the aperture.

4. The mixer according to claim 1 , wherein the outlet zone comprises one or more mixing blades.

5. The mixer according to claim 4, wherein the one or more mixing blades are arranged in a plane perpendicular to the direction of flow at a location downstream from the second end of the inner pipe.Attorney Docket No. 2001 U-001866-WO-POA6. The mixer according to claim 4, wherein the one or more mixing blades are arranged asymmetrically.

7. The mixer according to claim 4, wherein the one or more mixing blades are formed integrally with the baffle.

8. The mixer according to claim 4, wherein the one or more mixing blades radially inwardly extend toward a centerline of the inner pipe.

9. The mixer according to claim 1 , further comprising another baffle poisoned inside the outer tube between the second end of the inner tube and the distal end of the boss.

10. The mixer according to claim 1 , wherein the inlet zone is configured to be coupled to an injection device.

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