CN219327568U - Mixing tube assembly and mixer assembly - Google Patents

Abstract

A mixing tube assembly comprising an outer tube, an inner tube, and an annular space; the outer tube includes a first end and a second end opposite the first end; the inner pipe comprises a porous pipe, and the porous pipe is provided with a plurality of airflow through holes penetrating through the pipe wall of the porous pipe; the perforated tube includes a third end and a fourth end opposite the third end; the perforated pipe further comprises a first installation claw integrally extending from the third end part, the first installation claw comprises a first inclined part which deflects outwards and a first welding part which extends from the first inclined part, first notches are respectively arranged at the edges of two sides of the first inclined part, and the first welding part is welded and fixed on the inner wall of the outer pipe. The first notch can enable the first mounting claw to release stress better, so that the risk of failure of a welding part is reduced, and the reliability of the structure is improved. A mixer assembly including the mixing tube assembly is also disclosed.

Description

Mixing tube assembly and mixer assembly

Technical Field

The utility model relates to a mixing pipe assembly and a mixer assembly, and belongs to the technical field of engine tail gas aftertreatment.

Background

Existing exhaust aftertreatment devices are typically provided with a mixer assembly to enhance the mixing effect of the exhaust gas and urea droplets. The mixer assembly includes a mixing tube assembly.

The mixing tube assembly in the related art includes an outer tube and an inner tube, wherein the inner tube is welded and fixed in the outer tube. When the exhaust gas aftertreatment device works, the inner tube is impacted by air flow, so that how to improve the mixing tube assembly to improve the structural reliability is a technical problem faced by the person skilled in the art.

Disclosure of Invention

The utility model aims to provide a mixing pipe assembly and a mixer assembly with high reliability.

In order to achieve the above purpose, the utility model adopts the following technical scheme: a mixing tube assembly for use in an exhaust aftertreatment device, the mixing tube assembly comprising an outer tube, an inner tube at least partially within the outer tube, and an annular space between the outer tube and the inner tube; the outer tube includes a first end and a second end opposite the first end; the inner pipe comprises a porous pipe, the porous pipe is provided with a plurality of airflow through holes penetrating through the pipe wall of the porous pipe, and the airflow through holes are communicated with the annular space; the perforated tube includes a third end and a fourth end opposite the third end; the perforated pipe further comprises a first installation claw integrally extending from the third end part, the first installation claw comprises a first inclined part which deflects outwards and a first welding part which extends from the first inclined part, first notches are respectively arranged at the edges of two sides of the first inclined part, and the first welding part is welded and fixed on the inner wall of the outer pipe.

As a further improved technical solution of the present utility model, the perforated tube further comprises two first notches recessed from the third end, wherein the root of the first mounting claw is in communication with and located between the two first notches.

The utility model also discloses a mixer assembly comprising: a housing and a mixing tube assembly at least partially located in the housing, the housing comprising a first cavity and a second cavity, the first cavity being in direct or indirect communication with the second cavity, one end of the mixing tube assembly being located in the first cavity, the other end of the mixing tube assembly being located in the second cavity, the mixing tube assembly being the aforementioned mixing tube assembly, the annular space being in communication with the first cavity and the second cavity; the inner pipe comprises a cyclone pipe protruding out of the outer pipe along the axial direction and positioned in the first cavity, the cyclone pipe is provided with a first pipe inner cavity, a plurality of cyclone sheets and airflow openings corresponding to the cyclone sheets, and the airflow openings are communicated with the first cavity and the first pipe inner cavity; the perforated tube is provided with a second tube cavity communicated with the first tube cavity, the airflow through hole is communicated with the second tube cavity and the annular space, and the annular space is configured to enable airflow to flow through so as to heat and/or insulate the inner tube.

As a further improved technical scheme of the utility model, the shell comprises a first shell and a second shell, wherein the first cavity is communicated with the second cavity through the mixing pipe assembly.

As a further development of the utility model, the first lumen communicates with the second lumen via the first tube lumen and the second tube lumen, and the annular space.

As a further improved technical scheme of the utility model, the first end part is positioned in the first cavity, the second end part is positioned in the second cavity, and the swirl plate at least partially protrudes out of the first end part along the axial direction.

As a further improved technical scheme of the utility model, the outer tube comprises a flanging part which is arranged at the first end part and is flanged outwards.

As a further development of the utility model, the third end extends into the first cavity and the fourth end extends into the second cavity.

According to the technical scheme of the utility model, a plurality of first mounting claws are arranged, and a first spacing groove for allowing air flow to pass through is formed between two adjacent first mounting claws.

As a further improved technical scheme of the utility model, the perforated pipe further comprises a plurality of second mounting claws extending from the fourth end, and the second mounting claws are fixed on the inner wall of the outer pipe; a second spacing groove for air flow to pass through is formed between two adjacent second mounting claws.

As a further improved technical scheme of the utility model, the mixer assembly further comprises a fixed ring sleeved on the perforated pipe, the fixed ring is provided with a plurality of third mounting claws, and the third mounting claws are fixed on the inner wall of the outer pipe; a third spacing groove for air flow to pass through is formed between two adjacent third mounting claws.

As a further improved technical scheme of the utility model, the cyclone tube and the porous tube are split two parts and are mutually connected; or alternatively

The swirl tube is a single piece with the perforated tube.

Compared with the prior art, the first mounting claw comprises a first inclined part deflected outwards and a first welding part extending from the first inclined part, and two side edges of the first inclined part are respectively provided with a first notch. So set up, when first welded part welded fastening in the inner wall of outer tube, first notch can make first installation jaw release stress better to reduce the risk that the welded part takes place to become invalid, improved the reliability of structure.

In addition, the mixing tube assembly of the present utility model includes an outer tube, an inner tube at least partially disposed within the outer tube, and an annular space between the outer tube and the inner tube, the annular space communicating the first cavity with the second cavity, the annular space configured to flow a gas stream therethrough to heat and/or insulate the inner tube. By the arrangement, on one hand, the inner pipe is heated and/or insulated by utilizing the temperature of the tail gas, so that a relatively high temperature environment is provided for evaporation of urea liquid drops injected into the inner pipe, the risk of urea crystallization is reduced, the performance of resisting urea crystallization is improved, and the uniformity of ammonia gas is improved; on the other hand, by letting part of the gas flow through the annular space, it is advantageous to reduce the back pressure.

Drawings

FIG. 1 is a schematic diagram of an exhaust aftertreatment device of the present disclosure in one embodiment.

Fig. 2 is a schematic perspective view of a mixer assembly of the present utility model in one embodiment.

Fig. 3 is an exploded perspective view of fig. 2.

Fig. 4 is a schematic perspective view of a mixing tube assembly in one embodiment.

Fig. 5 is a top view of fig. 4.

Fig. 6 is a top view of the outer tube of fig. 5 removed.

Fig. 7 is a left side view of fig. 4.

Fig. 8 is a schematic cross-sectional view taken along line A-A in fig. 7.

Fig. 9 is an exploded perspective view of fig. 4.

Fig. 10 is a schematic perspective view of a mixing tube assembly in another embodiment.

Fig. 11 is a top view of the perforated tube of fig. 10.

Fig. 12 is a partial enlarged view of the circled portion B in fig. 11.

Fig. 13 is a right side view of fig. 11.

Detailed Description

Specific embodiments of the present utility model will be described in detail below with reference to the attached drawings, wherein features of the embodiments may be combined with each other without conflict if several embodiments exist. When the description refers to the accompanying drawings, the same numbers or symbols in different drawings indicate the same or similar elements unless otherwise indicated. What is described in the following exemplary embodiments does not represent all embodiments of the utility model, but rather is merely an example of a product consistent with the utility model as set forth in the claims of the utility model.

The terminology used in the present utility model is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present utility model. It should be understood that words such as "first," "second," and the like, used in the description and in the claims of the present utility model, do not denote any order, quantity, or importance, but rather are names used to distinguish one feature from another.

Referring to fig. 1 to 13, the present utility model discloses an exhaust gas aftertreatment device, which includes a Diesel Oxidation Catalyst (DOC) 1, a Diesel Particulate Filter (DPF) 2 located downstream of the diesel oxidation catalyst 1 and connected to the diesel oxidation catalyst 1, and a Selective Catalytic Reduction (SCR) 3 located downstream of the diesel particulate filter 2. The exhaust gas aftertreatment device further comprises a mixer assembly 4 connected between the diesel particulate filter 2 and the selective catalytic reducer 3.

The mixer assembly 4 comprises a housing 6, a mixing tube assembly 7 at least partly located in the housing 6, and a spoiler 8 located below the mixing tube assembly 7. The housing 6 comprises a first cavity 601 and a second cavity 602, and the first cavity 601 is directly or indirectly communicated with the second cavity 602. In the illustrated embodiment of the utility model, the housing 6 comprises a first housing 61 and a second housing 62, wherein the first cavity 601 communicates with the second cavity 602 through the mixing tube assembly 7.

One end of the mixing tube assembly 7 is located in the first cavity 601, and the other end of the mixing tube assembly 7 is located in the second cavity 602. The mixing tube assembly 7 comprises an outer tube 71, an inner tube 72 at least partially located within the outer tube 71, and an annular space 70 located between the outer tube 71 and the inner tube 72. The annular space 70 communicates with the first cavity 601 and the second cavity 602. In the illustrated embodiment of the utility model, the annular space 70 is perforated at both ends, and a portion of the air flow flowing from the first cavity 601 into the annular space 70 can directly flow into the second cavity 602.

The inner tube 72 includes a swirl tube 721 axially protruding from the outer tube 71 and located in the first cavity 601, the swirl tube 721 being provided with a first tube inner chamber 7210, a plurality of swirl vanes 7211 and air flow openings 7212 corresponding to the swirl vanes 7211. The air flow opening 7212 communicates the first cavity 601 with the first tube lumen 7210. In the illustrated embodiment of the utility model, the swirl tube 721 is substantially tapered, with a small upper end and a large lower end. Of course, those skilled in the art will appreciate that the swirl tube 721 may be provided in a cylindrical shape having the same upper and lower diameters.

The inner tube 72 further comprises a porous tube 722, the porous tube 722 being provided with a second tube lumen 7220 communicating with the first tube lumen 7210 and a number of gas flow through holes 7223 penetrating the wall of the porous tube 722. The airflow through-hole 7223 communicates with the second tube lumen 7220 and the annular space 70, the annular space 70 being configured to allow airflow therethrough to heat and/or insulate the inner tube 72.

In the illustrated embodiment of the utility model, the first lumen 601 communicates with the second lumen 602 through the first tube lumen 7210 and the second tube lumen 7220. At the same time, the first cavity 601 is also in communication with the second cavity 602 through the annular space 70.

The outer tube 71 comprises a first end 711 and a second end 712 opposite to the first end 711, the first end 711 is located in the first cavity 601, the second end 712 is located in the second cavity 602, and the swirl plate 7211 protrudes at least partially from the first end 711 along the axial direction. In order to better guide the inflow of the air flow, the outer tube 71 further comprises a turned-up portion 713 provided at the first end 711 and turned-up outwards.

The perforated tube 722 includes a third end 7221 and a fourth end 7222 opposite the third end 7221, the third end 7221 extending into the first cavity 601 and the fourth end 7222 extending into the second cavity 602. In other words, the third end 7221 is located in the first cavity 601, and the fourth end 7222 is located in the second cavity 602.

In order to facilitate the fixation of the inner tube 72 without excessively affecting the flow of the air flow, the perforated tube 722 further comprises a plurality of first mounting claws 7227 extending from the third end 7221, the first mounting claws 7227 being fixed to the inner wall of the outer tube 71; a first spaced groove 7224 for allowing air flow to pass therethrough is formed between adjacent two first mounting claws 7227. Referring to fig. 6, in one embodiment of the present utility model, the perforated tube 722 further includes two first notches 7227a recessed from the third end 7221 corresponding to each of the first mounting claws 7227, wherein the root of the first mounting claw 7227 communicates with the two first notches 7227a and is located between the two first notches 7227 a. By providing the first notch 7227a, it is advantageous to release the welding stress of the first mounting jaw 7227, reducing the risk of failure thereof.

The perforated tube 722 further includes a plurality of second mounting claws 7225 extending from the fourth end 7222, the second mounting claws 7225 being fixed to the inner wall of the outer tube 71; a second spaced groove 7226 for allowing air flow to pass therethrough is formed between two adjacent second mounting claws 7225. Referring to fig. 6, in one embodiment of the present utility model, the perforated tube 722 further includes two second notches 7225a recessed from the fourth end portion 7222 corresponding to each of the second mounting claws 7225, wherein the root portion of the second mounting claw 7225 communicates with the two second notches 7225a and is located between the two second notches 7225 a. By providing the second notch 7225a, the welding stress of the second mounting jaw 7225 is advantageously released, reducing the risk of failure thereof.

The mixer assembly 4 further comprises a fixing ring 723 sleeved on the perforated pipe 722, the fixing ring 723 is provided with a plurality of third mounting claws 7231, and the third mounting claws 7231 are fixed on the inner wall of the outer pipe 71; a third spaced groove 7232 for allowing the air flow to pass is formed between the adjacent two third mounting claws 7231.

The swirl tube 721 and the porous tube 722 are split two parts and are connected with each other; or the swirl tube 721 is a single piece with the perforated tube 722.

In the illustrated embodiment of the utility model, the swirl tube 721 and the porous tube 722 are two separate pieces. The swirl tube 721 is partially inserted into the perforated tube 722 and is fixed by welding.

The perforated tube 722 includes a first tube body 722a and a second tube body 722b, the plurality of air flow holes 7223 includes a plurality of first through holes 7223a provided on the first tube body 722a and a plurality of second through holes 7223b provided on the second tube body 722b, wherein the first through holes 7223a are circular holes, and the second through holes 7223b are elongated holes extending in the axial direction. The first pipe body 722a and the second pipe body 722b are split two parts and are mutually connected; or the first body portion 722a and the second body portion 722b may be a single piece. The securing ring 723 is located approximately at the interface of the first pipe portion 722a and the second pipe portion 722 b.

The spoiler 8 is generally omega-shaped to spoiler the air flow exiting the mixer assembly 4 to form a double swirl. The arrangement is beneficial to further improving the evaporation of urea and reducing the crystallization risk on one hand; on the other hand, to improve the uniformity of the gas flow through the inlet end face of the selective catalytic reducer 3.

The housing 6 is further provided with a nozzle mount 63 mounted on top of the first housing 61. The nozzle mount 63 is used to mount a urea nozzle 5, and the urea nozzle 5 is used to spray atomized urea droplets into the inner tube 72.

Referring to fig. 10 to 13, in another embodiment of the mixing tube assembly 7 of the present utility model, the perforated tube 722 further includes a first mounting claw 7227 integrally extended from the third end portion 7221, the first mounting claw 7227 includes a first inclined portion 7228 which is deflected outwards and a first welding portion 7229 extended from the first inclined portion 7228, both side edges of the first inclined portion 7228 are respectively provided with a first notch 7227b, and the first welding portion 7229 is welded to the inner wall of the outer tube 71.

Further, the perforated tube 722 further includes two first notches 7227a recessed from the third end 7221, wherein the root of the first mounting jaw 7227 communicates with the two first notches 7227a and is located between the two first notches 7227 a.

In comparison with the prior art, the first mounting jaw 7227 of the present utility model includes a first inclined portion 7228 which is outwardly deflected and a first welding portion 7229 which extends from the first inclined portion 7228, both side edges of the first inclined portion 7228 are respectively provided with first recesses 7227b. With this arrangement, when the first welding portion 7229 is welded to the inner wall of the outer tube 71, the first notch 7227b can make the first mounting jaw 7227 release stress better, thereby reducing the risk of failure of the welding portion and improving the reliability of the structure. In addition, the first notch 7227a facilitates the release of the welding stress of the first mounting jaw 7227, further reducing the risk of failure thereof.

The working principle of the tail gas aftertreatment device of the utility model is approximately as follows: exhaust gas discharged from a diesel engine flows through the Diesel Oxidation Catalyst (DOC) 1 and the Diesel Particulate Filter (DPF) 2 and then flows into the mixer assembly 4; a portion of the exhaust gas flowing into the first cavity 601 is guided by the cyclone sheet 7211, passes through the airflow openings 7212 and flows into the first pipe inner cavity 7210; at the same time, another part of the exhaust gas flowing into the first cavity 601 directly flows into the annular space 70; when the injection conditions are reached, the urea nozzle 5 injects atomized urea droplets into the inner tube 72; the tail gas is mixed with the urea droplets in the inner tube 72, and the urea droplets evaporate to produce ammonia gas; since the first through hole 7223a and the second through hole 7223b communicate the second tube lumen 7220 with the annular space 70, a portion of the air flow in the inner tube 72 may pass through the first through hole 7223a and the second through hole 7223b to flow into the annular space 70; of course, part of the air flow in the annular space 70 may also flow into the inner tube 72 through the first through holes 7223a and the second through holes 7223 b; subsequently, the gas flow exits from the bottom of the mixing tube assembly 7; the air flow exiting the mixing tube assembly 7 is secondarily disturbed by the spoiler 8 and then relatively uniformly flows toward the selective catalytic reducer 3.

In contrast to the prior art, the mixing tube assembly 7 of the present utility model comprises an outer tube 71, an inner tube 72 at least partially located within the outer tube, and an annular space 70 located between the outer tube 71 and the inner tube 72, the annular space 70 being in communication with the first cavity 601 and the second cavity 602, the annular space 70 being configured to allow a flow of air to flow therethrough for heating and/or maintaining the inner tube 72. So configured, the present utility model facilitates heating and/or maintaining the inner tube with the temperature of the exhaust gas, thereby providing a relatively high temperature environment for evaporation of urea droplets injected into the inner tube 72, reducing the risk of urea crystallization, and improving the resistance to urea crystallization. In addition, because urea is wrapped by the high-temperature gas of the outer layer, the heat exchange between the urea and the tail gas is facilitated, and the evaporation and the decomposition of the urea are more complete, so that the ammonia uniformity is improved. At the same time, the present utility model facilitates reducing backpressure by allowing a portion of the gas flow to flow through the annular space 70.

The above embodiments are only for illustrating the present utility model and not for limiting the technical solutions described in the present utility model, and it should be understood that the present utility model should be based on those skilled in the art, and although the present utility model has been described in detail with reference to the above embodiments, it should be understood by those skilled in the art that modifications or equivalent substitutions can be made to the present utility model without departing from the spirit and scope of the present utility model and modifications thereof should be covered by the scope of the claims of the present utility model.

Claims (12)

1. A mixing tube assembly for use in an exhaust aftertreatment device, the mixing tube assembly comprising an outer tube, an inner tube at least partially disposed within the outer tube, and an annular space between the outer tube and the inner tube; the outer tube includes a first end and a second end opposite the first end; the inner pipe comprises a porous pipe, the porous pipe is provided with a plurality of airflow through holes penetrating through the pipe wall of the porous pipe, and the airflow through holes are communicated with the annular space; the perforated tube includes a third end and a fourth end opposite the third end; the perforated pipe further comprises a first installation claw integrally extending from the third end part, the first installation claw comprises a first inclined part which deflects outwards and a first welding part which extends from the first inclined part, first notches are respectively arranged at the edges of two sides of the first inclined part, and the first welding part is welded and fixed on the inner wall of the outer pipe.

2. The mixing tube assembly of claim 1, wherein: the perforated tube further includes two first indentations recessed from the third end, wherein the root of the first mounting jaw communicates with and is located between the two first indentations.

3. A mixer assembly, comprising: the shell and at least part be located the hybrid tube subassembly in the shell, the shell includes first cavity and second cavity, first cavity with the second cavity is direct or indirect be linked together, the one end of hybrid tube subassembly is located in the first cavity, the other end of hybrid tube subassembly is located in the second cavity, its characterized in that: the mixing tube assembly of claim 1 or 2, the annular space communicating the first cavity with the second cavity; the inner pipe comprises a cyclone pipe protruding out of the outer pipe along the axial direction and positioned in the first cavity, the cyclone pipe is provided with a first pipe inner cavity, a plurality of cyclone sheets and airflow openings corresponding to the cyclone sheets, and the airflow openings are communicated with the first cavity and the first pipe inner cavity; the perforated tube is provided with a second tube cavity communicated with the first tube cavity, the airflow through hole is communicated with the second tube cavity and the annular space, and the annular space is configured to enable airflow to flow through so as to heat and/or insulate the inner tube.

4. A mixer assembly as set forth in claim 3 wherein: the housing includes a first housing and a second housing, wherein the first cavity communicates with the second cavity through the mixing tube assembly.

5. The mixer assembly of claim 4 wherein: the first lumen communicates with the second lumen through the first and second tube lumens and the annular space.

6. The mixer assembly of claim 1 wherein: the first end is located in the first cavity, the second end is located in the second cavity, and the swirl plate at least partially protrudes out of the first end along the axial direction.

7. The mixer assembly of claim 6 wherein: the outer tube includes a turn-up portion provided at the first end portion and turned up outwardly.

8. A mixer assembly as set forth in claim 3 wherein: the third end extends into the first cavity and the fourth end extends into the second cavity.

9. The mixer assembly of claim 8 wherein: the first installation claws are a plurality of, and a first interval groove for air flow to pass through is formed between two adjacent first installation claws.

10. The mixer assembly of claim 9 wherein: the perforated pipe further comprises a plurality of second mounting claws extending from the fourth end, and the second mounting claws are fixed on the inner wall of the outer pipe; a second spacing groove for air flow to pass through is formed between two adjacent second mounting claws.

11. The mixer assembly of claim 10 wherein: the mixer assembly further comprises a fixing ring sleeved on the perforated pipe, the fixing ring is provided with a plurality of third mounting claws, and the third mounting claws are fixed on the inner wall of the outer pipe; a third spacing groove for air flow to pass through is formed between two adjacent third mounting claws.

12. A mixer assembly as set forth in claim 3 wherein: the swirl tube and the porous tube are split two parts and are mutually connected; or alternatively

The swirl tube is a single piece with the perforated tube.

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