Double delta-wing static mixer and method for mixing gas

Abstract

The present invention discloses a double delta wing static mixer, comprising at least one group of static mixing devices, the static mixing device comprising at least one double delta wing mixing unit, the double delta wing mixing unit comprising two horizontally arranged mixing monomers and two vertically arranged mixing monomers, the two horizontally arranged mixing monomers are symmetrically arranged with a first diagonal line, the two vertically arranged mixing monomers are symmetrically arranged with a second diagonal line, and the tips of the two horizontally arranged mixing monomers and the two vertically arranged mixing monomers are all intersected at one point. A method for mixing gas is also disclosed. The double delta wing static mixer of the present invention has a simple structure, is easy to arrange, has a good gas mixing effect, has a small resistance, has a small impact on the original flow field in the flue, and is suitable for project transformation.

Description

Technical Field

[0001] The present invention relates to the field of industrial flue gas purification such as coal-fired boilers, industrial boilers, sintering machines, etc., and in particular to a double delta-wing static mixer and a gas mixing method. Background Art

[0002] As an efficient nitrogen oxide (NOx) control technology, the selective catalytic reduction (SCR) flue gas denitrification technology has been widely used in coal-fired power plants. However, due to the load and coal quality of coal-fired units and the lack of theoretical guidance for on-site operation, the SCR flue gas denitrification system often encounters many problems during commissioning, such as catalyst wear, low ammonia utilization, and denitrification efficiency that does not meet the design requirements. The flue gas denitrification ammonia spray mixing system in the selective catalytic reduction (SCR) method is an important component. Whether ammonia and flue gas can be stably and evenly mixed directly affects the denitrification efficiency and ammonia escape rate. Therefore, the reasonable and efficient organization of the ammonia-flue gas flow field has become the core of the SCR denitrification technology. Since the SCR denitrification system often faces limited layout space and short flue ducts, the flue gas flow distribution in the flue duct is uneven, resulting in uneven ammonia-flue gas mixing, which seriously reduces the denitrification efficiency, increases the ammonia escape rate, and brings about uneven fly ash mixing, which further aggravates the serious ash accumulation of the denitrification system catalyst and the downstream air preheater.

[0003] In order to achieve uniform distribution of various flue gas components, fly ash, temperature and other parameters, it is generally necessary to arrange one or more groups of static mixers in the flue of the SCR system, and effectively shorten the mixing distance between ammonia and flue gas, so that ammonia and flue gas can be better mixed and evenly mixed. The uniform distribution of ammonia can not only improve the denitrification efficiency, but also extend the catalyst replacement cycle, reduce the amount of ammonia escape, reduce the corrosion and blockage of the air preheater, and reduce investment and operation management costs; the uniform distribution of fly ash can reduce local wear of the flue, reduce system resistance, and avoid dust accumulation and wear of the catalyst; the uniform distribution of the temperature field can increase the minimum ammonia injection temperature of the SCR system, so that the SCR system can better cope with changes in flue gas load. In summary, a mixer with excellent performance has become the key to the process design of the SCR flue gas denitrification system. However, in actual engineering applications, especially for ultra-low emission renovation projects, some static mixers improve the mixing efficiency on the one hand, but bring a series of problems such as increased system resistance, severe dust accumulation, and deterioration of the flow field. Summary of the invention

[0004] The purpose of the present invention is to provide a new type of double delta wing static mixer and a method for mixing gas in order to solve the technical deficiencies of the existing mixer. The double delta wing static mixer of the present invention has a simple structure, is easy to arrange, has a good mixing effect, and can evenly mix the NOx, fly ash concentration and temperature field in the flue gas; the method for mixing gas of the present invention has little effect on the original flow field in the flue, has a small amount of engineering work for the modification project, has a high mixing efficiency, and has a small system resistance.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions: a double delta-wing static mixer, comprising at least one group of static mixing devices, the static mixing device comprising at least one double delta-wing mixing unit, the double delta-wing mixing unit comprising two laterally arranged mixing monomers and two longitudinally arranged mixing monomers, the two laterally arranged mixing monomers being symmetrically arranged with a first diagonal line, the two longitudinally arranged mixing monomers being symmetrically arranged with a second diagonal line, the two laterally arranged mixing monomers and the two longitudinally arranged mixing monomers having a tip that intersects at one point. The double delta-wing mixing unit is formed by splicing four mixing monomers,

[0006] In the aforementioned double delta-wing static mixer, the two transversely arranged mixing units and the two longitudinally arranged mixing units each include a straightening blade and a first rotating blade and a second rotating blade, one side of the first rotating blade is connected to one side of the straightening blade, and one side of the second rotating blade is connected to the other side of the straightening blade. The first rotating blade and the second rotating blade are acute-angled triangular blades of the same shape.

[0007] In the aforementioned double delta-wing static mixer, the rectifying blades include a first triangular blade and a second triangular blade, a tip of the first triangular blade is connected to a tip of the second triangular blade, the first rotating blade is connected to one side of the first triangular blade, and the second rotating blade is connected to one side of the second triangular blade. The first triangular blade and the second triangular blade are right-angled triangular blades of the same shape.

[0008] The double-delta-wing type mixing unit is formed by splicing four mixing monomers, which is easy to manufacture. The mixing monomer is formed by splicing two triangular blades of different shapes, and the manufacturing cost is low.

[0009] In the aforementioned double delta-wing static mixer, the static mixing device is installed in the flue, and the angle α between the first rotating blade and the central section of the flue is 20 to 80 degrees; the angle β between the second rotating blade and the central section of the flue is 20 to 80 degrees.

[0010] In the aforementioned double delta-wing static mixer, the static mixing device comprises four double delta-wing mixing units, and the four double delta-wing mixing units are connected in sequence.

[0011] In the aforementioned double delta-wing static mixer, the static mixing device comprises eight double delta-wing mixing units, four of each double delta-wing mixing units are connected in sequence in a row, and the eight double delta-wing mixing units are arranged in two rows and two columns.

[0012] The aforementioned double delta-wing type static mixer comprises two sets of static mixing devices, and both sets of static mixing devices are installed in the flue of the degassing system.

[0013] As described above, the method for mixing gas using a double-delta wing static mixer includes installing a double-delta wing static mixer in the flue of a degassing system; forming a local rotating mixing zone in the flue after the static mixing device through a static mixing device composed of a double-delta wing mixing unit, and mixing the gas evenly in the local rotating mixing zone; using the double-delta wing mixing unit to form a gas rotating mixed state for the gas after passing through the double-delta wing mixing unit, thereby forming a local rotating mixing zone in the flue after the static mixing device; using the mixing monomer of the double-delta wing mixing unit to divide the gas passing through the double-delta wing mixing unit, and changing the flow direction of the divided gas, thereby forming a gas rotating mixed state between the divided gases; using the straightening blades of the mixing monomer to divide the gas passing through the double-delta wing mixing unit, and changing the flow direction of the divided gas using the rotating blades of the mixing monomer.

[0014] The aforementioned method of mixing gases comprises installing a first set of static mixing devices in the horizontal section flue of the denitrification system; and / or installing a second set of static mixing devices in the vertical section flue of the denitrification system; the gases comprise ammonia gas sprayed into the ammonia spray grid and the flue gas and nitrogen oxide gas in the flue; the ammonia gas sprayed into the ammonia spray grid and the flue gas and nitrogen oxide gas in the flue are uniformly mixed by the first set of static mixing devices; the ammonia gas, the flue gas and the nitrogen oxide gas are further uniformly mixed by the second set of static mixing devices; the nitrogen oxide gas is nitric oxide and nitrogen dioxide.

[0015] The rectifying blades of the double delta-wing type mixing unit divide the incoming gas into two parts, which are then passed through the first swirl blade and the second swirl blade to form a gas rotation mixing effect. The mixing effect can be adjusted and optimized by adjusting the angles of the first swirl blade and the second swirl blade.

[0016] Through the segmentation effect of the rectifying blades, the flue gas in a large range of a certain flue section can be segmented, and then the first rotating blade and the second rotating blade are used to change the segmented gas, so that the gas can be mixed more fully. The first rotating blade and the second rotating blade at different angles can produce gases with different rotation angles, and rely on the mixing and rotation of local gases to form a uniform mixing effect of flue gas in different areas. Since the fly ash concentration, flue gas temperature field and flue gas distribution are directly related, the uniformity of the fly ash concentration and temperature field can be improved while the flue gas is mixed evenly.

[0017] The double delta-wing mixing unit produces local mixing of gas rather than the overall swirl of gas in the flue, and will not have a fundamental impact on the main flow of gas in the flue. Therefore, it has little impact on the original flow field and is particularly suitable for the implementation of renovation projects.

[0018] like Figure 6 As shown, the double delta airfoil mixing unit is determined by the size of the circumscribed rectangular frame. Assuming that the size of the circumscribed rectangular frame is a*a*(b+c), the size of the rectifying blade is two right triangles with two right angles of b and √a / 2 and two right angles of c and √a / 2. The angle α between the first rotating blade and the center section of the flue and the angle β between the second rotating blade and the center section of the flue can also be obtained through geometric relationships. By changing the height b and c of the circumscribed rectangular frame, the angles α and β can be adjusted, thereby changing the rotation intensity of the static mixer on the flue gas. The angles α and β can be adjusted between 20 degrees and 80 degrees.

[0019] It should be noted that the double delta-wing static mixer and the gas mixing method of the present invention are applicable to, but not limited to, coal-fired boilers in thermal power plants, industrial furnaces, and the metallurgical industry.

[0020] Compared with the prior art, the flow field simulation of the double delta wing static mixer of the present invention shows that the smoke resistance of the double delta wing static mixer of the present invention is small, the influence on the original flow field in the flue is small, and there is no need to modify the original guide plate in the flue, which is suitable for the implementation of the modification project with low modification cost. The method of the present invention can improve the problem of uneven mixing of ammonia and flue gas in the flue, improve the denitration efficiency of the system, reduce the loss of ammonia, reduce the ammonia escape rate at the denitration outlet, and greatly shorten the mixing distance of ammonia and flue gas. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute an improper limitation to the present invention. In the accompanying drawings:

[0022] Figure 1 It is a schematic structural diagram of the static mixing device of the present invention;

[0023] Figure 2 It is a schematic structural diagram of a double delta-wing type mixing unit of the present invention;

[0024] Figure 3 It is a schematic diagram of the structure of the mixed monomer of the present invention;

[0025] Figure 4 It is a schematic diagram of the structure of the double delta-wing static mixer of the present invention installed in the flue;

[0026] Figure 5 is a top view of a double delta-wing type mixing unit of the present invention;

[0027] Figure 6 Schematic diagram of the placement angle of the double delta-wing type mixing unit of the present invention;

[0028] Figure 7 It is a three-dimensional display diagram of the mixed monomer of the present invention;

[0029] Figure 8 It is a flow field simulation comparison diagram of the present invention and the traditional static mixer.

[0030] Figure numerals: 1-static mixing device, 2-double triangular airfoil mixing unit, 3-transversely arranged mixing monomer, 4-longitudinally arranged mixing monomer, 5-first diagonal line, 6-second diagonal line, 7-straightening blade, 8-first rotating blade, 9-second rotating blade, 10-first triangular blade, 11-second triangular blade, 12-central hole area, 13-outer opening area, 14-first group of static mixing devices, 15-second group of static mixing devices.

[0031] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. DETAILED DESCRIPTION

[0032] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention are clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0033] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0034] Embodiment 1 of the present invention: A double-delta-wing static mixer comprises a group of static mixing devices 1, the static mixing device 1 comprises at least one double-delta-wing mixing unit 2, the double-delta-wing mixing unit 2 comprises two laterally arranged mixing monomers 3 and two longitudinally arranged mixing monomers 4, the two laterally arranged mixing monomers 3 are symmetrically arranged about a first diagonal line 5, the two longitudinally arranged mixing monomers 4 are symmetrically arranged about a second diagonal line 6, and the tips of the two laterally arranged mixing monomers 3 and the two longitudinally arranged mixing monomers 4 intersect at one point.

[0035] Embodiment 2 of the present invention: A double delta-wing static mixer, including two groups of static mixing devices 1, both of which are installed in the flue of the degassing system. The static mixing device 1 includes at least one double delta-wing mixing unit 2, and the double delta-wing mixing unit 2 includes two laterally arranged mixing monomers 3 and two longitudinally arranged mixing monomers 4, the two laterally arranged mixing monomers 3 are symmetrically arranged with respect to the first diagonal line 5, and the two longitudinally arranged mixing monomers 4 are symmetrically arranged with respect to the second diagonal line 6, and the tips of the two laterally arranged mixing monomers 3 and the two longitudinally arranged mixing monomers 4 are all connected at one point. The two laterally arranged mixing monomers 3 and the two longitudinally arranged mixing monomers 4 both include a straightening blade 7 and a first rotating blade 8 and a second rotating blade 9, one side of the first rotating blade 8 is connected to one side of the straightening blade 7, and one side of the second rotating blade 9 is connected to the other side of the straightening blade 7.

[0036] Embodiment 3 of the present invention: A double delta-wing static mixer comprises a group of static mixing devices 1, wherein the static mixing device 1 comprises four double delta-wing mixing units 2, and the four double delta-wing mixing units are connected in sequence. The double delta-wing mixing unit 2 comprises two laterally arranged mixing monomers 3 and two longitudinally arranged mixing monomers 4, wherein the two laterally arranged mixing monomers 3 are symmetrically arranged with respect to the first diagonal line 5, and the two longitudinally arranged mixing monomers 4 are symmetrically arranged with respect to the second diagonal line 6, and the tips of the two laterally arranged mixing monomers 3 and the two longitudinally arranged mixing monomers 4 are all intersected at one point. The two laterally arranged mixing monomers 3 and the two longitudinally arranged mixing monomers 4 each comprise a straightening blade 7 and a first rotating blade 8 and a second rotating blade 9, wherein one side of the first rotating blade 8 is connected to one side of the straightening blade 7, and one side of the second rotating blade 9 is connected to the other side of the straightening blade 7. The straightening blade 7 comprises a first triangular blade 10 and a second triangular blade 11, wherein one tip of the first triangular blade 10 is connected to one tip of the second triangular blade 11, the first rotating blade 8 is connected to one side of the first triangular blade 10, and the second rotating blade 9 is connected to one side of the second triangular blade 11.

[0037] Embodiment 4 of the present invention: A double delta-wing static mixer comprises a group of static mixing devices 1, wherein the static mixing device 1 comprises four double delta-wing mixing units 2, and the four double delta-wing mixing units are connected in sequence. The double delta-wing mixing unit 2 comprises two laterally arranged mixing monomers 3 and two longitudinally arranged mixing monomers 4, wherein the two laterally arranged mixing monomers 3 are symmetrically arranged with respect to the first diagonal line 5, and the two longitudinally arranged mixing monomers 4 are symmetrically arranged with respect to the second diagonal line 6, and the tips of the two laterally arranged mixing monomers 3 and the two longitudinally arranged mixing monomers 4 are all intersected at one point. The two laterally arranged mixing monomers 3 and the two longitudinally arranged mixing monomers 4 each comprise a straightening blade 7 and a first rotating blade 8 and a second rotating blade 9, wherein one side of the first rotating blade 8 is connected to one side of the straightening blade 7, and one side of the second rotating blade 9 is connected to the other side of the straightening blade 7. The straightening blade 7 comprises a first triangular blade 10 and a second triangular blade 11, wherein one tip of the first triangular blade 10 is connected to one tip of the second triangular blade 11, the first rotating blade 8 is connected to one side of the first triangular blade 10, and the second rotating blade 9 is connected to one side of the second triangular blade 11. The static mixing device 1 is installed in the flue, and the angle α between the first rotating blade 8 and the central section of the flue is 20 to 80 degrees; the angle β between the second rotating blade 9 and the central section of the flue is 20 to 80 degrees.

[0038] Embodiment 5 of the present invention: A double delta-wing static mixer comprises a group of static mixing devices 1, wherein the static mixing device 1 comprises eight double delta-wing mixing units 2, wherein every four double delta-wing mixing units 2 are connected in sequence in a row, and the eight double delta-wing mixing units 2 are arranged in two rows and two columns. The double delta-wing mixing units 2 comprise two laterally arranged mixing monomers 3 and two longitudinally arranged mixing monomers 4, wherein the two laterally arranged mixing monomers 3 are symmetrically arranged about a first diagonal line 5, and the two longitudinally arranged mixing monomers 4 are symmetrically arranged about a second diagonal line 6, and the tips of the two laterally arranged mixing monomers 3 and the two longitudinally arranged mixing monomers 4 are all connected at one point. The two laterally arranged mixing monomers 3 and the two longitudinally arranged mixing monomers 4 both comprise a straightening blade 7 and a first rotating blade 8 and a second rotating blade 9, wherein one side of the first rotating blade 8 is connected to one side of the straightening blade 7, and one side of the second rotating blade 9 is connected to the other side of the straightening blade 7. The rectifying blade 7 includes a first triangular blade 10 and a second triangular blade 11, a tip of the first triangular blade 10 is connected to a tip of the second triangular blade 11, a first rotating blade 8 is connected to one side of the first triangular blade 10, and a second rotating blade 9 is connected to one side of the second triangular blade 11. The static mixing device 1 is installed in the flue, and the angle α between the first rotating blade 8 and the center section of the flue is 20 to 80 degrees; the angle β between the second rotating blade 9 and the center section of the flue is 20 to 80 degrees.

[0039] Embodiment 6 of the present invention: A double delta-wing static mixer comprises a group of static mixing devices 1, wherein the static mixing device 1 comprises a plurality of double delta-wing mixing units 2, wherein the plurality of double delta-wing mixing units 2 are spread over the entire flue cross section. The double delta-wing mixing units 2 comprise two laterally arranged mixing monomers 3 and two longitudinally arranged mixing monomers 4, wherein the two laterally arranged mixing monomers 3 are symmetrically arranged about a first diagonal line 5, and the two longitudinally arranged mixing monomers 4 are symmetrically arranged about a second diagonal line 6, and the tips of the two laterally arranged mixing monomers 3 and the two longitudinally arranged mixing monomers 4 are all connected at one point. The two laterally arranged mixing monomers 3 and the two longitudinally arranged mixing monomers 4 both comprise a straightening blade 7 and a first rotating blade 8 and a second rotating blade 9, wherein one side of the first rotating blade 8 is connected to one side of the straightening blade 7, and one side of the second rotating blade 9 is connected to the other side of the straightening blade 7. The rectifying blade 7 includes a first triangular blade 10 and a second triangular blade 11, a tip of the first triangular blade 10 is connected to a tip of the second triangular blade 11, a first rotating blade 8 is connected to one side of the first triangular blade 10, and a second rotating blade 9 is connected to one side of the second triangular blade 11. The static mixing device 1 is installed in the flue, and the angle α between the first rotating blade 8 and the center section of the flue is 20 to 80 degrees; the angle β between the second rotating blade 9 and the center section of the flue is 20 to 80 degrees.

[0040] Embodiment 6 of the present invention: A method for mixing gas, comprising installing a double-delta airfoil static mixer in a degassing system flue; a rectangular frame is welded around the double-delta airfoil mixing unit, a support beam is provided in the flue, the rectangular frame is provided on the support beam, and the support beam is used to support and fix the double-delta airfoil mixing unit.

[0041] A static mixing device composed of a double delta-wing mixing unit is used to form a local rotating mixing zone in the flue behind the static mixing device, and the gas is mixed evenly in the local rotating mixing zone; the double delta-wing mixing unit is used to form a gas rotating mixing state for the gas after passing through the double delta-wing mixing unit, thereby forming a local rotating mixing zone in the flue behind the static mixing device; the mixing monomer of the double delta-wing mixing unit is used to divide the gas passing through the double delta-wing mixing unit, and the flow direction of the divided gas is changed, thereby forming a gas rotating mixing state between the divided gases; the straightening blades of the mixing monomer are used to divide the gas passing through the double delta-wing mixing unit, and the rotating blades of the mixing monomer are used to change the flow direction of the divided gas.

[0042] Embodiment 7 of the present invention: A method for mixing gases, comprising installing a first set of static mixing devices in a horizontal section flue of a degassing system, and installing a second set of static mixing devices in a vertical section flue of the degassing system; using a static mixing device composed of a double delta-wing mixing unit to form a local rotating mixing zone in the flue behind the static mixing device, and mixing the gases uniformly in the local rotating mixing zone; using the double delta-wing mixing unit to form a gas rotating mixed state for the gases after passing through the double delta-wing mixing unit, thereby forming a local rotating mixing zone in the flue behind the static mixing device; using a mixing monomer of the double delta-wing mixing unit to divide the gases passing through the double delta-wing mixing unit, and changing the flow direction of the divided gases, thereby forming a gas rotating mixed state between the divided gases; using the straightening blades of the mixing monomer to divide the gases passing through the double delta-wing mixing unit, and changing the flow direction of the divided gases by the rotating blades of the mixing monomer. The gas includes ammonia gas injected from the ammonia injection grid, flue gas and nitrogen oxide gas in the flue; the ammonia gas injected from the ammonia injection grid, flue gas and nitrogen oxide gas in the flue are evenly mixed through a first group of static mixing devices; the ammonia gas, flue gas and nitrogen oxide gas are further evenly mixed through a second group of static mixing devices; the nitrogen oxide gas includes nitric oxide and nitrogen dioxide.

[0043] The working principle of the present invention applied in the smoke duct of the destocking system is as follows:

[0044] The flue gas enters the denitrification system from the outlet of the economizer of the coal-fired power plant boiler, passes through a group of guide plates, and then ammonia is sprayed into the ammonia injection grid, and the flue gas-ammonia is mixed through the first group of static mixing devices 14. When the ammonia-flue gas passes through the first group of static mixing devices 14, the flue gas flowing through the center of the flue and near the flue wall is divided by the rectifying blades 7 of the laterally arranged mixing monomer 3 and the longitudinally arranged mixing monomer 4. After being divided by the rectifying blades 7, the direction of the divided flue gas is changed by the first rotating blades 8 and the second rotating blades 9, that is, flue gas in the central area and flue gas in the outer area are formed. The flue gas in the central area passes through the double-delta wing static mixer through the central hole area 12, and the flue gas in the outer area passes through the double-delta wing static mixer through the outer opening area 13, and then two layers of inner and outer rotating mixing areas are formed, so that the local vortex forms a strong rotating vortex in the clockwise or counterclockwise direction, thereby making the flue gas-ammonia mixing more sufficient and uniform; then, the flue gas-ammonia is further mixed evenly through the second group of static mixing devices 15, and finally enters the denitrification reactor through the guidance of the guide plate.

[0045] like Figure 7 As shown, by comparing the flow field simulation experimental data of the static mixer of the present invention and the conventional static mixer, it can be seen that the velocity deviation at the outlet of the double delta-wing static mixer of the present invention is reduced by about 30%, and the concentration deviation is reduced by about 25%. In terms of resistance, it is reduced by about 20% compared with the conventional static mixer.

Claims

1. A double delta-wing static mixer, characterized in that: The invention comprises at least one group of static mixing devices (1), wherein the static mixing device (1) comprises at least one double delta-wing type mixing unit (2), wherein the double delta-wing type mixing unit (2) comprises two mixing monomers (3) arranged transversely and two mixing monomers (4) arranged longitudinally, wherein the two mixing monomers (3) arranged transversely are symmetrically arranged along a first diagonal line (5), and the two mixing monomers (4) arranged longitudinally are symmetrically arranged along a second diagonal line (6), and the tips of the two mixing monomers (3) arranged transversely and the two mixing monomers (4) arranged longitudinally are connected at one point; and the two mixing monomers (3) arranged transversely and the two mixing monomers (4) arranged longitudinally each comprise a straightening blade (7) and a first rotating blade (8) and A second rotating blade (9), one side of the first rotating blade (8) is connected to one side of the rectifying blade (7), and one side of the second rotating blade (9) is connected to the other side of the rectifying blade (7); the rectifying blade (7) includes a first triangular blade (10) and a second triangular blade (11), a tip of the first triangular blade (10) is connected to a tip of the second triangular blade (11), the first rotating blade (8) is connected to one side of the first triangular blade (10), and the second rotating blade (9) is connected to one side of the second triangular blade (11); two sets of static mixing devices (1) are included, and the two sets of static mixing devices (1) are both installed in the flue of the denitration system.

2. A double delta-wing static mixer according to claim 1, characterized in that: The static mixing device (1) is installed in a flue, and the angle α between the first rotating blade (8) and the central cross section of the flue is 20 to 80 degrees; the angle β between the second rotating blade (9) and the central cross section of the flue is 20 to 80 degrees.

3. A double delta-wing static mixer according to claim 1, characterized in that: The static mixing device (1) comprises four double delta-wing type mixing units (2), and the four double delta-wing type mixing units are connected in sequence.

4. A double delta-wing static mixer according to claim 1, characterized in that: The static mixing device (1) comprises eight double-delta wing type mixing units (2), four of each double-delta wing type mixing units (2) are connected in sequence in a row, and the eight double-delta wing type mixing units (2) are arranged in two rows and two columns.

5. A method for mixing gas using a double delta-wing static mixer according to any one of claims 1 to 4, comprising installing the double delta-wing static mixer in a flue of a denitration system; Installing a first set of static mixing devices in the flue of the horizontal section of the denitrification system; and / or installing a second set of static mixing devices in the vertical flue of the denitrification system; The gas includes ammonia gas injected from the ammonia injection grid and flue gas and nitrogen oxide gas in the flue; The ammonia gas injected from the ammonia injection grid and the flue gas and nitrogen oxide gas in the flue are mixed uniformly through the first group of static mixing devices; The ammonia gas, flue gas and nitrogen oxide gas are further mixed uniformly by a second set of static mixing devices; The nitrogen oxide gas includes nitrogen monoxide and nitrogen dioxide.

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