A denitration system mixing device

Abstract

The utility model provides a kind of denitration system mixing device, belong to tail gas mixing field, comprising: shell, shell includes two symmetrical recess, recess cross section is set as arc structure;Flow divider, it is set in shell, cross section is set as "<", opening is towards the gas outlet end of shell;Two arc baffles, symmetrically set in shell interior, and set in recess inboard, opening is towards the air inlet end of shell.The denitration system mixing device of the present application intensifies the effect of tail gas turbulent flow in the whole process, is conducive to the breaking and decomposition of urea water solution droplet, accelerates the mixing of urea and tail gas, thereby avoids urea crystallization, improves the effect of ship diesel engine tail gas purification.

Description

Technical Field

[0001] This utility model relates to the field of denitrification device technology, and in particular to a denitrification system mixing device. Background Technology

[0002] Selective catalytic reduction (SCR) has become the mainstream technology for denitrification of marine diesel engine exhaust gas as a flue gas denitrification technology. Due to increasingly stringent regulations and limited space on board ships, higher requirements are placed on the denitrification efficiency of SCR reactors. On the one hand, higher catalyst efficiency is required, and on the other hand, the SCR system needs to occupy less space, so that the reducing agent mixed with exhaust gas can be more evenly distributed on the catalyst cross section in a compact SCR reactor.

[0003] However, in existing marine engine SCR systems, urea is injected into the exhaust gas pipe and mixed by evaporation inside the pipe. Due to the straight pipe design and the certain flow velocity of the exhaust gas, the high-speed airflow inside the pipe carries urea droplets into the reactor, causing the urea solution to be rushed into the reactor by the high-speed airflow before it is fully mixed, thus affecting the purification effect of marine diesel engine exhaust gas.

[0004] Patent No. CN201020660443.0 discloses a mixing device for a diesel engine urea SCR system, comprising a pipe body, a mixer vane assembly, and a nozzle. The nozzle is characterized by being positioned on the central axis of the pipe body, the mixer vane assembly being close to the nozzle and installed at the nozzle's front end, the mixer vane assembly consisting of a set of vanes, the vane body being a fan-shaped structure twisted along the airflow direction, its arrangement direction being consistent with the spray axis direction, and each vane having a set of inclined guide vanes.

[0005] However, due to the straight cylindrical design of the pipe and the limitation of its size, the high-speed airflow inside the pipe carries urea droplets into the reactor, causing the urea solution to be rushed into the reactor before it is fully mixed, thus affecting the purification effect of marine diesel engine exhaust. Utility Model Content

[0006] To address the above problems, this utility model provides a mixing device for a denitrification system.

[0007] A denitrification system mixing device includes: a shell, the shell including two symmetrically arranged grooves, the grooves having an arc-shaped cross-section; a flow divider plate disposed inside the shell, having a "<" shaped cross-section and an opening facing the air outlet end of the shell; and two arc-shaped baffles symmetrically disposed inside the shell and on the inner side of the grooves, with openings facing the air inlet end of the shell.

[0008] In a preferred embodiment, the denitrification system mixing device includes: a longitudinal baffle, fixedly disposed on the opening side of the diversion plate and disposed perpendicular to the housing.

[0009] In a preferred embodiment, the denitrification system mixing device includes: a transition pipe, which is fixedly disposed between two arc-shaped baffles and between two grooves.

[0010] In a preferred embodiment, the denitrification system mixing device includes: a spiral vane disposed inside the transition tube and fixed to the housing by a support frame.

[0011] In a preferred embodiment, the central symmetry lines OO' of the housing, transition tube, propeller plate, and two splitter plates coincide.

[0012] In a preferred embodiment, the groove transitions smoothly with the manifold.

[0013] In a preferred embodiment, the shortest distance between the manifold and the housing is 0.8-1.2 times the shortest distance between the manifold and the arc-shaped baffle.

[0014] In this application, the exhaust gas and urea mixture of the denitrification system enter from the inlet end 13 of the shell, are divided into upper and lower streams by the diverter plate, and then blocked by the groove and arc baffle to form a rotating airflow. The two airflows finally converge and collide in the middle of the shell, and are finally discharged from the outlet end of the shell. The whole process intensifies the turbulence of the exhaust gas, which is conducive to the breakup and decomposition of urea aqueous solution droplets, accelerates the mixing of urea and exhaust gas, thereby avoiding the formation of urea crystals and improving the purification effect of marine diesel engine exhaust gas. Attached Figure Description

[0015] Other features and advantages of the present invention will become clear from the following description of exemplary embodiments, which is incorporated in and constitutes a part of this specification. The accompanying drawings, which illustrate embodiments of the present invention and, together with the description, serve to explain the principles of the present invention. In these drawings, similar reference numerals are used to denote similar elements. The drawings described below are some embodiments of the present invention, but not all embodiments. Other drawings will be readily available to those skilled in the art based on these drawings without any inventive effort.

[0016] Figure 1 Cross-sectional view of the mixing device in the denitrification system of this utility model; Figure 2 Structural diagram of the mixing device in the denitrification system of this utility model; In the diagram: 10, shell; 11, groove; 20, splitter plate; 12, exhaust end; 30, arc baffle; 13, intake end; 21, longitudinal baffle; 31, transition pipe; 40, propeller plate; 41, support frame. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be arbitrarily combined with each other.

[0018] The mixing device of the denitrification system will be described in detail below with reference to the accompanying drawings and embodiments. Example

[0019] A denitrification system mixing device includes: a housing 10, the housing 10 including two symmetrically arranged grooves 11, the grooves 11 having an arc-shaped cross-section; a flow divider 20 disposed inside the housing 10, having a "<" shaped cross-section, with its opening facing the air outlet 12 of the housing 10; and two arc-shaped baffles 30 symmetrically disposed inside the housing 10 and inside the grooves 11, with their openings facing the air inlet 13 of the housing 10.

[0020] During operation, the exhaust gas and urea mixture enter from the inlet 13 of the housing 10, is split into two streams by the diverter 20, and then blocked by the groove 11 and the arc baffle 30, forming a rotating airflow. The two airflows finally converge and collide in the middle of the housing 10, and are finally discharged from the outlet 12 of the housing 10. This enhances the effect of exhaust gas turbulence, which is beneficial for the breakup and decomposition of urea solution droplets, accelerates the mixing of urea and exhaust gas, thereby preventing urea crystallization and improving the purification effect of marine diesel engine exhaust gas.

[0021] The central symmetry line OO' of the shell 10, the transition tube 31, the propeller plate 40, and the two splitter plates 20 coincides.

[0022] The groove 11 and the diverter plate 20 are smoothly connected.

[0023] The shortest distance between the diverter plate 20 and the housing 10 is 0.8-1.2 times the shortest distance between the diverter plate 20 and the arc baffle 30. Example

[0024] Example 2 is an improvement on Example 1. The improvement includes: the denitrification system mixing device includes: a longitudinal baffle 21, which is fixedly installed on the opening side of the diversion plate 20 and is arranged perpendicular to the housing 10.

[0025] In this process, after the airflow is blocked by the arc baffle 30 to form a rotating airflow, the near-arc structure formed by the longitudinal baffle 21 and the diverter 20 further generates rotating airflows with different directions of rotation, thereby accelerating the mixing of urea and exhaust gas, thus avoiding the formation of urea crystals and improving the purification effect of marine diesel engine exhaust gas.

[0026] The included angle of the "<" structure of the diverter plate 20 is 40-60°. Example

[0027] Example 3 is an improvement on Example 1. The improvement includes: the denitrification system mixing device includes: a transition pipe 31, which is fixedly disposed between two arc baffles 30 and between two grooves 11.

[0028] By setting the transition pipe 31, the poor flow of the mixture of urea and exhaust gas in the angled area between the groove 11 and the arc baffle 30 is avoided, thus preventing the formation of a dead zone and avoiding crystallization. Example

[0029] Example 4 is an improvement on Example 1. The improvement includes: the denitrification system mixing device includes: a spiral blade 40, which is disposed inside the transition pipe 31 and fixed to the housing 10 by a support frame 41.

[0030] By setting the spiral vane 40, the mixture of urea and exhaust gas flows out of the arc baffle 30 and is further mixed, thereby avoiding the formation of urea crystals and improving the purification effect of marine diesel engine exhaust gas.

[0031] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or apparatus comprising a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or apparatus. Without further limitations, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the article or apparatus that includes that element.

[0032] The above embodiments are only used to illustrate the technical solution of this utility model and are not intended to limit it. The utility model has been described in detail with reference to preferred embodiments. Those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solution of this utility model without departing from the spirit and scope of the technical solution of this utility model, and all such modifications and substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A mixing device for a denitrification system, characterized in that, include: The housing (10) includes two symmetrically arranged grooves (11), the grooves (11) having an arc-shaped cross-section; A diverter plate (20) is disposed inside the housing (10), with a cross-section in the shape of "<" and an opening facing the air outlet (12) of the housing (10). Two arc-shaped baffles (30) are symmetrically arranged inside the housing (10) and inside the groove (11), with their openings facing the air inlet end (13) of the housing (10).

2. The mixing device of the denitrification system according to claim 1, characterized in that, The denitrification system mixing device includes: A longitudinal baffle (21) is fixedly installed on the opening side of the diverter plate (20) and is perpendicular to the housing (10).

3. The mixing device for the denitrification system according to claim 1, characterized in that, The denitrification system mixing device includes: The transition tube (31) is fixedly disposed between the two arc baffles (30) and between the two grooves (11).

4. The mixing device of the denitrification system according to claim 3, characterized in that, The denitrification system mixing device includes: The propeller plate (40) is disposed inside the transition tube (31) and fixed inside the housing (10) by the support frame (41).

5. The mixing device for the denitrification system according to claim 4, characterized in that, The central symmetry lines OO' of the housing (10), the transition tube (31), the propeller plate (40), and the two diverter plates (20) coincide.

6. The mixing device of the denitrification system according to claim 1, characterized in that, The groove (11) transitions smoothly with the flow divider (20).

7. The mixing device for the denitrification system according to claim 1, characterized in that, The shortest distance between the diverter plate (20) and the housing (10) is 0.8-1.2 times the shortest distance between the diverter plate (20) and the arc baffle (30).

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