阅读说明：本技术 一种双涡旋流式尿素混合装置 (Double-vortex flow type urea mixing device ) 是由 陈增响 张辉 陈正国 张旭 付细平 徐东 易军 周稳超 陆超俊 宋伟 彭新宇 于 2021-09-27 设计创作，主要内容包括：本发明涉及一种双涡旋流式尿素混合装置,属于柴油机尾气后处理领域,其包括前法兰、后法兰、筒体、隔热罩、喷嘴底座和筒内组件,所述前法兰与后法兰分别焊接在筒体两端,所述隔热罩焊接在筒体的外部,所述喷嘴底座焊接在筒体上,所述筒内组件焊接于筒体内部并与喷嘴底座相连接；所述筒内组件包括前隔板、后隔板及分流管组,其中前隔板与后隔板分别焊接在分流管组的两侧。本发明采用简单的管子和挡板结构实现了尿素的分流及双涡流旋转,提升了尿素和废气的混合效果,又保证SCR催化单元的混合均匀性；采用的分流管上端的槽口,用于引导气流从分流管两侧进入分流管中,从而顺利带走上方喷入的尿素,降低尿素喷射在分流管内壁面上累积。(The invention relates to a double-vortex-flow urea mixing device, which belongs to the field of diesel engine tail gas aftertreatment and comprises a front flange, a rear flange, a cylinder, a heat insulation shield, a nozzle base and an in-cylinder assembly, wherein the front flange and the rear flange are respectively welded at two ends of the cylinder; the in-barrel assembly comprises a front partition plate, a rear partition plate and a shunt tube group, wherein the front partition plate and the rear partition plate are respectively welded on two sides of the shunt tube group. The invention adopts simple pipe and baffle structure to realize urea shunt and double vortex rotation, thus improving the mixing effect of urea and waste gas and ensuring the mixing uniformity of the SCR catalytic unit; the notch at the upper end of the flow dividing pipe is used for guiding airflow to enter the flow dividing pipe from two sides of the flow dividing pipe, so that urea sprayed from the upper part is smoothly taken away, and urea spraying accumulation on the inner wall surface of the flow dividing pipe is reduced.)

1. The double-vortex-flow urea mixing device is characterized by comprising a front flange (1), a rear flange (2), a cylinder body (3), a heat insulation cover (4), a nozzle base (5) and an in-cylinder assembly (6), wherein the front flange (1) and the rear flange (2) are respectively welded at two ends of the cylinder body (3), the heat insulation cover (4) is welded outside the cylinder body (3), the nozzle base (5) is welded on the cylinder body (3), and the in-cylinder assembly (6) is welded inside the cylinder body (3) and connected with the nozzle base (5);

the in-barrel assembly (6) comprises a front partition plate (61), a rear partition plate (62) and a shunt tube group (63), wherein the front partition plate (61) and the rear partition plate (62) are respectively welded on two sides of the shunt tube group (63);

the flow dividing pipe group (63) comprises a supporting plate (631), a flow dividing pipe (632), an inverted V-shaped crushing guide plate (633), an arc guide plate (634) and a partition plate (635), wherein a round hole is formed in the middle of the supporting plate (631), the middle of the flow dividing pipe (632) is welded on the round hole, the bottom of the flow dividing pipe (632) is welded on the arc guide plate (634), and the inverted V-shaped crushing guide plate (633) is welded inside the flow dividing pipe (632); first notches (636) are respectively formed in two sides of the upper end of the shunt pipe (632), notches (637) are respectively formed in two sides of the lower end of the shunt pipe (632), and a partition plate (635) is arranged between the two notches (637).

2. A double vortex flow urea mixing device according to claim 1, characterized by that the middle of the front partition (61) is provided with arc shaped ventilation holes (611).

3. A double vortex flow urea mixing device according to claim 1, characterized by the fact that the front partition (61) and the rear partition (62) are welded to the support plate (631) and the partition (635), respectively.

4. A twin scroll urea mixer according to claim 1 where the top of the manifold (632) is formed with a plurality of flat holes (638), the flat holes (638) are located on the same horizontal line, and the flat holes (638) are arranged to be evenly spaced around the periphery of the manifold (632).

5. A double vortex flow urea mixing device according to claim 1, characterised in that the rear partition (62) is provided with second notches (621) on both sides.

6. A double vortex flow urea mixing device according to claim 1, characterized in that the inverted V-shaped crushing deflector (633) is provided with a plurality of small round holes (639) uniformly.

7. A double vortex flow urea mixing device according to claim 1, characterized by the fact that the support plate (631) is provided at both ends with first arc-shaped edges (6331) that are inclined upwards.

8. A twin scroll urea mixer apparatus as defined in claim 1 wherein the baffle (635) is welded at the bottom to the curved baffle (634) and the baffle (635) is welded at the middle to the bypass duct (632).

9. A double vortex urea mixer device according to claim 8, characterized in that the partition (635) is perpendicular to the tangent plane of the weld with the shunt tube (632).

10. A double vortex flow type urea mixing device according to claim 1, wherein the arc-shaped deflector (634) is provided with a first groove (6341), and the first groove (6341) is provided at two ends of the welding position of the arc-shaped deflector (634) and the shunt pipe (632); and two ends of the arc-shaped guide plate (634) are provided with second arc-shaped edges (6342) which are inclined upwards.

Technical Field

The invention relates to a double-vortex flow type urea mixing device, and belongs to the field of diesel engine tail gas aftertreatment.

Background

In the application technology of the SCR system, how to uniformly mix the injected urea and the engine exhaust gas and complete the secondary crushing of the urea and reduce the crystallization risk of the urea at the mixer position is the key in the whole development process.

The common mixing unit of urea blender uses fin structure, orifice plate structure, fibre unit etc. to realize the breakage and the decomposition of urea more, adopts orifice plate or orifice tube structure or whirl structure to realize the mixture of urea simultaneously. However, most of the common swirl structures on the market generate unidirectional swirl, so that the flow velocity uniformity and the ammonia uniformity in the catalytic unit are improved. In recent years, there is also an application in which a plurality of swirl structures are used to form a bidirectional swirl action to improve the mixing effect before SCR. However, on the one hand, the mixing device using the plurality of swirling structures is too complicated in structure, resulting in high exhaust back pressure. On the other hand, the simple rotational flow structure has limited breaking capacity and flow dividing effect on urea, and although the hole pipe has total flow dividing function, the small holes are easy to be blocked to cause serious urea crystallization, so that the flow dividing and decomposition of urea are difficult to be rapidly completed.

Disclosure of Invention

The invention aims to overcome the defects and provide the urea mixing device which can realize double-rotation vortex by adopting a set of vortex structure, so that the problems of poor mixing uniformity, slow urea distribution and poor decomposition in an SCR system are solved, and urea crystallization is prevented.

According to the technical scheme provided by the invention, the double-vortex-flow urea mixing device comprises a front flange, a rear flange, a cylinder, a heat insulation cover, a nozzle base and an in-cylinder assembly, wherein the front flange and the rear flange are respectively welded at two ends of the cylinder, the heat insulation cover is welded at the outer part of the cylinder, the nozzle base is welded on the cylinder, and the in-cylinder assembly is welded in the cylinder and is connected with the nozzle base;

the in-cylinder assembly comprises a front clapboard, a rear clapboard and a shunt tube group, wherein the front clapboard and the rear clapboard are respectively welded on two sides of the shunt tube group;

the flow distribution pipe group comprises a support plate, flow distribution pipes, an inverted V-shaped crushing guide plate, an arc-shaped guide plate and a partition plate, wherein a round hole is formed in the middle of the support plate, the middle of each flow distribution pipe is welded on the round hole, the bottom of each flow distribution pipe is welded on the arc-shaped guide plate, and the inverted V-shaped crushing guide plate is welded inside each flow distribution pipe; first notches are formed in two sides of the upper end of the flow dividing pipe respectively, notches are formed in two sides of the lower end of the flow dividing pipe respectively, and a partition plate is arranged between the two notches.

As a further improvement of the invention, the middle part of the front clapboard is provided with an arc-shaped vent hole.

As a further improvement of the invention, the front partition plate and the rear partition plate are respectively welded with the supporting plate and the partition plate.

As a further improvement of the invention, the top end of the shunt tube is provided with a plurality of flat holes, the flat holes are positioned on the same horizontal line, and the flat holes are uniformly distributed around the periphery of the shunt tube.

As a further improvement of the invention, both sides of the rear clapboard are provided with second notches.

As a further improvement of the invention, a plurality of small round holes are uniformly arranged on the inverted V-shaped crushing guide plate.

As a further improvement of the invention, both ends of the supporting plate are provided with first arc-shaped edges which incline upwards.

As a further improvement of the invention, the bottom of the baffle plate is welded on the arc-shaped guide plate, and the middle part of the baffle plate is welded on the shunt pipe.

As a further improvement of the invention, the baffle is perpendicular to the tangent plane of the welding part of the shunt pipe.

As a further improvement of the invention, the arc-shaped guide plate is provided with a first groove, and the first groove is arranged at two ends of the welding position of the arc-shaped guide plate and the flow dividing pipe; and two ends of the arc-shaped guide plate are provided with second arc-shaped edges which incline upwards.

The invention has the beneficial effects that:

1. the invention adopts simple pipe and baffle structure to realize urea shunt and double vortex rotation, thus improving the mixing effect of urea and waste gas and ensuring the mixing uniformity of the SCR catalytic unit;

2. the two sides of the upper end of the flow dividing pipe are provided with the notches, and the notches are used for guiding airflow to enter the flow dividing pipe from the two sides of the flow dividing pipe, so that urea sprayed from the upper part is smoothly taken away, and the urea sprayed on the inner wall surface of the flow dividing pipe is reduced from accumulating;

3. the split-flow crushing plate is arranged in the split-flow pipe, so that secondary crushing of urea is facilitated, the split-flow effect of the urea and waste gas to two sides is promoted, and the possibility of excessive accumulation of the urea at the same position is reduced;

4. the lower end of the flow dividing pipe adopts a n-shaped guide plate to guide the air flow to two sides, so that the strength of the bidirectional vortex is improved, urea is prevented from accumulating at the bottommost part of the mixing device, and the crystallization risk at the bottom is reduced;

5. two side flow guide cavities which guide the air flow to two sides are constructed by utilizing the front and the rear partition plate structures, so that the mixing space of the urea is enlarged;

6. air grooves are formed in two sides of the rear partition plate, so that air flow can be discharged from two sides in a rotating mode and can rotate towards the center, and two rotating vortexes are formed. The two rotating vortexes interact with each other, so that the uniformity of the airflow of the catalytic unit and the uniformity of the urea mixing are improved.

Drawings

Fig. 1 is a schematic view of the overall structure of the present invention.

Fig. 2 is a schematic structural diagram of the in-cartridge assembly of the present invention.

Fig. 3 is a partial cross-sectional view of the in-cartridge assembly.

Fig. 4 is an exploded view of the components within the cartridge.

Description of reference numerals: the nozzle comprises a front flange 1, a rear flange 2, a barrel 3, a heat shield 4, a nozzle base 5, an in-barrel assembly 6, a front partition plate 61, a rear partition plate 62, a flow dividing pipe group 63, a vent hole 611, a second notch 621, a supporting plate 631, a flow dividing pipe 632, an inverted V-shaped crushing guide plate 633, an arc-shaped guide plate 634, a partition plate 635, a first notch 636, a notch 637, a flat hole 638, a small circular hole 639, a first arc-shaped edge 6331, a first groove 6341 and a second arc-shaped edge 6342.

Detailed Description

The invention will be further described with reference to examples in the drawings to which:

as shown in fig. 1 and 2, the double vortex urea mixing device of the present invention mainly comprises a rear front flange 1, a rear flange 2, a cylinder 3, a heat shield 4, a nozzle base 5, an inner assembly 6, and so on. The front flange 1 and the rear flange 2 are respectively welded at two ends of the cylinder 3 and are used for being connected with structures such as an SCR catalytic unit; the heat shield 4 is welded outside the cylinder 3 and used for preserving heat and insulating heat, reducing the heat loss of the mixing device and improving the exhaust temperature in the mixing device. The nozzle base 5 is welded at the position of the opening on the cylinder body and used for installing a urea nozzle and spraying urea in the using process. The subassembly 6 welds inside barrel 3, is connected with nozzle base 5 for the mixture of urea, breakage form the double vortex simultaneously, promote the mixed effect of urea, reduce urea crystallization risk.

As shown in fig. 3 and 4, the cartridge assembly 6 is mainly composed of a front partition 61, a rear partition 62, and a flow dividing tube group 63, wherein the front partition 61 and the rear partition 62 are respectively welded to two sides of the flow dividing tube group 63. The shunt tube assembly 63 is mainly composed of a support plate 631, a shunt tube 632, an inverted V-shaped crushing guide plate 633, an arc guide plate 634 and a partition plate 635. The front partition plate 61 and the rear partition plate 62 are respectively welded with the support plate 631 and the partition plate 635 and are used for blocking incoming flow and guiding the incoming flow to enter the shunt pipe from the notches at the two sides of the shunt pipe 6-3-2; the middle part of the front baffle plate 61 is provided with an arc-shaped vent hole 611, urea is deposited on the flow dividing pipe 632 through the flow of air flow in the barrel 3, the inverted-V-shaped crushing guide plate 633 is welded inside the flow dividing pipe 632 and keeps a certain distance with the bottom arc-shaped guide plate 634, a plurality of small round holes 639 are uniformly arranged on the inverted-V-shaped crushing guide plate 633, and the sprayed urea has a certain crushing effect, so that the secondary crushing and decomposition process of the urea is accelerated; the middle part of backup pad 631 is opened there is the round hole, the middle part welding of shunt tubes 632 sets up on the round hole, the bottom welding of shunt tubes 632 sets up on arc guide plate 634, first notch 636 has been seted up respectively to the both sides of shunt tubes 632 upper end, and breach 637 has been seted up respectively to the both sides of shunt tubes 632 lower extreme, is provided with baffle 635 between two breach 637.

The two sides of the rear partition plate 62 are provided with second notches 621, and two mixing chambers are formed between the rear partition plate 62 and the front partition plate 61, the flow dividing pipe 632, the partition plate 635 and the arc-shaped guide plate 634 on the two sides, so as to guide the air flow to be discharged from the notches 621 on the two sides of the rear partition plate 62 and form two vortex flows, and the two ends of the support plate 631 are provided with first arc-shaped edges 6331 which are inclined upwards, so that the air flow guiding direction can be received.

The dividing tube 632 has notches 637 formed at both sides of the lower end thereof for guiding the air flow to enter from the first notches 636 at both sides of the upper end thereof and to be discharged from the notches 637 at both sides of the lower end thereof, thereby forming bidirectional vortex flows at both sides.

The top end of the shunt tube 632 is provided with a plurality of flat holes 638, the flat holes 638 are arranged on the same horizontal line and are arranged to surround the periphery of the shunt tube 632 for guiding part of the air flow to form axial air flow, so as to prevent urea accumulation and crystallization on the nozzle base 5.

The bottom of the baffle 635 is welded on the arc-shaped guide plate 634, the middle of the baffle 635 is welded on the shunt tube 632, and the baffle 635 is perpendicular to the tangent plane of the welding position of the shunt tube 632, so that the baffle 635 and the rear baffle 62 can be conveniently welded.

The arc-shaped guide plate 634 is provided with first grooves 6341, and the first grooves 6341 are disposed at two ends of the welding position of the arc-shaped guide plate 634 and the shunt tube 632; the two ends of the arc-shaped guide plate 634 are provided with second arc-shaped edges 6342 which are inclined upwards, so that the downward air flow is received by the first groove 6341, and then the air flow forms a vortex by the second arc-shaped edges 6342.

The working process is as follows:

in practical application, the mixing device is respectively connected with the particle trap and the SCR catalytic unit through a front flange 1 and a rear flange 2. The urea mixer has the effects of mixing air flow and urea, improving mixing efficiency, improving the decomposition and crushing effect of urea and reducing urea crystallization.

When the air flow enters the mixing device, the air flow firstly enters the barrel body 3 and the in-barrel assembly 6, and due to the blocking of the front partition plate 61 and the rear partition plate 62, the air flow is forced to enter the shunt pipe 632 from the notches at the two sides of the upper end of the shunt pipe 632, and a blowing effect is formed on the urea spray beam sprayed at the nozzle base 5, so that the urea is prevented from accumulating on the side wall of the shunt pipe 632. Meanwhile, part of the air flow enters from the flat holes 638 distributed on the periphery at the uppermost end of the shunt pipe 632 and purges the bottom position of the nozzle base 5, so that small urea particles are prevented from accumulating and crystallizing at the bottom position of the nozzle base 5. The airflow entering the shunt tube 632 is shunted to two sides under the action of the inverted V-shaped crushing guide plate 633 in the process of downward impact. Meanwhile, a plurality of small round holes 639 are uniformly arranged on the inverted-V-shaped crushing guide plate 633, so that the sprayed urea is crushed to a certain degree, and the secondary crushing and decomposition process of the urea is accelerated.

The breach discharge of shunt tubes 632 lower extreme both sides will be followed to the air current after being shunted by the broken guide plate 633 of type of falling V, and get into preceding baffle 61 under arc guide plate 634's water conservancy diversion effect, back baffle 62, in the both sides mixing chamber that forms between the baffle 635, and finally discharge from the second notch 621 department of back baffle 62 both sides, thereby form clockwise rotation's vortex and anticlockwise rotation's vortex respectively in both sides position, two rotatory vortex interact, further promote the decomposition and the mixed effect of urea, ammonia mixing uniformity and air current mixing uniformity in the SCR catalytic unit have been guaranteed.

In general, urea is easily accumulated on the upper end of the bottom arc-shaped guide plate 634, and the inverted V-shaped crushing guide plate 633 arranged above the arc-shaped guide plate 634 can greatly reduce the risk of urea accumulation on the upper end of the arc-shaped guide plate 634.