Denitration catalyst mixed structure and denitration device
By adopting a catalyst arrangement method with a hybrid structure of honeycomb and flat plate regions in the SCR denitrification unit, the problems of catalyst wear and blockage caused by uneven airflow distribution are solved, achieving uniform catalytic denitrification of flue gas and efficient utilization of catalyst.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ZHEJIANG DOWAY ADVANCED TECH CO LTD
- Filing Date
- 2025-06-20
- Publication Date
- 2026-08-04
AI Technical Summary
Existing SCR denitrification units suffer from uneven airflow distribution, severe catalyst wear, and low utilization, leading to excessive ammonia slip and shortened catalyst life.
The catalyst arrangement adopts a hybrid structure of honeycomb and flat plate regions, with the honeycomb region in the middle and the flat plate region at the edge, to adapt to the flue gas requirements of different flow rate regions, taking advantage of the wear-resistant properties of the honeycomb region and the anti-clogging properties of the flat plate region.
This achieved uniform catalytic denitrification reaction of flue gas, extended the service life of the catalyst, and improved the overall utilization rate and denitrification effect of the catalyst.
Smart Images
Figure CN224585673U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to flue gas treatment equipment, and in particular to a denitrification catalyst hybrid structure and denitrification device. Background Technology
[0002] SCR (Selective Catalytic Reduction) is a mature flue gas denitrification technology widely used in post-furnace denitrification equipment. The principle of SCR flue gas denitrification involves injecting ammonia gas, acting as a reducing agent, into the outlet flue of the boiler economizer. The flue gas temperature in the flue ranges from 300 to 420°C. Under the action of a pre-placed catalyst, the reducing agent selectively reacts with nitrogen oxides in the flue gas to produce nitrogen and water, as illustrated in patents with authorization publication numbers CN110585921B, CN202036999U, and CN205280700U.
[0003] In existing technologies, the catalyst arrangement of SCR denitrification reactors mostly adopts a 3-layer structure. Initially, 2 layers of catalyst are loaded when the reactor is put into operation. After 24,000 hours of operation, about 3 years, a third layer is added to ensure the overall catalytic reaction effect. Thereafter, one layer is replaced every 3 years, and the replacement is carried out in a cyclical alternation according to the order of the 1st, 2nd and 3rd layers.
[0004] However, in practical applications, the following technical shortcomings still exist:
[0005] Firstly, the existing technology lacks a gas distribution layer for uniformly distributing airflow, resulting in large deviations in flue gas velocity in different areas of the flue. In particular, after passing through bends in the flue, the flow field distribution within the flue becomes uneven, leading to excessively high or low ammonia-nitrogen ratios in some areas. This means that the flue gas in areas with high flow velocity does not react fully, resulting in excessive ammonia escape.
[0006] On the other hand, there are many types of catalysts that can be used for SCR, but the commonly used structures of existing catalyst supports are only honeycomb and flat plate. Usually, the same type of catalyst and the same structure of catalyst support are used in a reactor. In this case, the non-uniformity of the flow field in the reactor will cause severe catalyst wear in the high flow velocity area and low catalyst utilization in the low flow velocity area. Moreover, dust is easy to adhere and cause blockage, affecting the overall service life of the catalyst and the catalytic effect, and increasing energy and material consumption. Summary of the Invention
[0007] The purpose of this invention is to address the shortcomings of existing technologies and provide a denitrification catalyst hybrid structure and a denitrification device.
[0008] To solve the above problems, the present invention adopts the following solution:
[0009] A denitrification catalyst hybrid structure includes a plate layer for supporting the catalyst; the plate layer includes a honeycomb region and a flat plate region; the honeycomb region is provided with a plurality of first airflow channels distributed in a regular polygonal shape, the first airflow channels being regularly distributed in the honeycomb region; the flat plate region is provided with a plurality of second airflow channels in the shape of strips, the second airflow channels being arranged in parallel in the flat plate region; the flat plate region is located at the edge of the plate layer, and the honeycomb region is located in the middle region of the plate layer.
[0010] Furthermore, the flat panel area is located on the left and right sides of the cellular area.
[0011] Furthermore, the honeycomb region occupies 40% to 80% of the surface area of the square plate layer.
[0012] Furthermore, symmetrical flat plate areas are provided on both sides of the honeycomb area, with one of the flat plate areas occupying half of the remaining area of the plate layer after the honeycomb area.
[0013] Furthermore, both the cellular region and the flat plate region are configured as square cells arranged in rows and columns; a first module is set in the cell of the cellular region, and a second module is set in the cell of the flat plate region; a first catalyst block with a first airflow channel is set in the first module, and a second catalyst block with a second airflow channel is set in the second module.
[0014] Furthermore, the length and width of the surface of the first catalyst block are consistent, ranging from 120mm to 200mm, and the wall thickness is from 0.5mm to 1mm; wherein the shape of the first gas flow channel is a regular quadrilateral, and the pore width is from 5mm to 10mm.
[0015] Furthermore, the length and width of the surface of the second catalyst block are both 120mm~200mm, and the wall thickness is 0.5mm~1mm; the pore width of the second gas flow channel is 5mm~10mm.
[0016] A denitrification device includes the above-mentioned denitrification catalyst hybrid structure.
[0017] Furthermore, it also includes a flue, which contains at least one layer of denitrification catalyst hybrid structure; the flat plate area in the denitrification catalyst hybrid structure is located on one side near the corner of the flue and on the other side near the corner of the flue.
[0018] The beneficial effects of this utility model are as follows:
[0019] By setting a honeycomb area in the middle and a flat plate area at the edge on the plate, the flue gas in different areas can undergo a full catalytic denitrification reaction, and the plate can also better resist the erosion of the flue gas and extend the overall service life of the plate.
[0020] By setting up a denitrification device with a mixed structure of denitrification catalysts, the flue gas with uneven flow velocity passing through the flue can achieve a good denitrification effect. By making reasonable use of the characteristics of different catalyst structures, the performance requirements of catalysts at different locations in the flue can be matched, thereby improving the overall utilization rate of catalysts. Attached Figure Description
[0021] Figure 1 This is a schematic diagram of the plate layers in Example 1;
[0022] Figure 2 This is a schematic diagram of a cell on a plate layer in Example 1;
[0023] Figure 3 This is a schematic diagram of the first module of Example 1;
[0024] Figure 4 This is a schematic diagram of the first catalytic fast catalyst in Example 1;
[0025] Figure 5 This is a schematic diagram of the second module of Example 1;
[0026] Figure 6 This is a schematic diagram of the second catalytic fastener in Example 1;
[0027] Figure 7 This is a schematic diagram of the denitrification device in Example 1.
[0028] Explanation of the symbols in the attached diagram: 1. Honeycomb area; 2. Flat plate area; 3. First module; 4. Second module; 5. First catalyst block; 6. Second catalyst block; 7. First airflow channel; 8. Second airflow channel; 9. Cell; 10. Flue; 11. Denitrification catalyst hybrid structure. Detailed Implementation
[0029] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that, unless otherwise specified, the following embodiments and features can be combined with each other.
[0030] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the figures only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.
[0031] Example 1:
[0032] like Figures 1-6 As shown, a denitrification catalyst hybrid structure includes a plate layer for supporting the catalyst. The material of the plate layer contains catalyst components, enabling the flue gas passing through the plate layer to react rapidly under the catalytic action of the catalyst. The plate layer includes a honeycomb region 1 and a flat plate region 2. The honeycomb region 1 is provided with a plurality of first airflow channels 7 distributed in a regular polygonal shape. The first airflow channels 7 are regularly distributed in the honeycomb region 1. In this example, the first airflow channels 7 are regular quadrilaterals, distributed in an n*m matrix. In some other embodiments, a honeycomb distribution can also be used. The flat plate region 2 is provided with a plurality of second airflow channels 8 in the shape of strips. The second airflow channels 8 are arranged in parallel in the flat plate region 2. The flat plate region 2 is located at the edge of the plate layer, and the honeycomb region 1 is located in the middle region of the plate layer. When flue gas flows within flue 10, the flue gas velocity is faster near the far corner of the flue and slower near the near corner. Therefore, a honeycomb region 1 is set in the middle area of the plate layer, which contains a catalyst with a higher density per unit area, and a flat plate region 2 is set in the edge area to deal with the faster and slower flue gas. The former is used to prevent rapid wear, and the latter is used to prevent dust blockage. This allows the flue gas in different areas to undergo sufficient catalytic denitrification reaction while effectively extending the overall service life.
[0033] The flat plate region 2 is located on the left and right sides of the honeycomb region 1. In this example, the left and right sides of the honeycomb region 1 correspond to the near-angle side and the far-angle side of the flue 10, respectively. It should be noted that the near-angle side of the flue 10 refers to the side closest to the nearest corner on the path of airflow into the plate layer within the flue 10, and similarly, the far-angle side refers to the side furthest from the nearest corner on the path of airflow into the plate layer within the flue 10. The flow velocity is slow on the near-angle side, and soot is easily accumulated and adhered, causing blockage. Therefore, a flat plate structure is chosen to increase the pore area and reduce the possibility of blockage. On the far-angle side, the flue gas velocity is fast, and the plate layer wears out faster. Therefore, a flat plate structure is chosen to reduce wear when passing through the flue gas and increase the overall lifespan.
[0034] The honeycomb region 1 occupies 40% to 80% of the surface area of the square plate layer; symmetrical flat plate regions 2 are provided on both sides of the honeycomb region 1, with one flat plate region 2 occupying half of the remaining surface area of the plate layer excluding the honeycomb region 1. In this example, the honeycomb region 1 occupies approximately 60% of the plate layer surface area, and the flat plate regions 2 on both sides of the honeycomb region 1 each occupy approximately 20% of the area. It should be noted that the flat plate region 2 on one side also provides second airflow channels 8 with two different arrangement directions, wherein the two arrangement directions are perpendicular to each other; the second airflow channels 8 with the same arrangement direction are located in the same column.
[0035] Both the honeycomb region 1 and the flat plate region 2 are configured as square cells 9 arranged in rows and columns; a first module 3 is set in the cell 9 of the honeycomb region 1, and a second module 4 is set in the cell 9 of the flat plate region 2; a first catalyst block 5 with a first airflow channel 7 is set in the first module 3, and a second catalyst block 6 with a second airflow channel 8 is set in the second module 4; this facilitates the adjustment of the distribution of different catalyst blocks on the plate.
[0036] The first catalyst block 5 has a uniform length and width, ranging from 120mm to 200mm, and a wall thickness of 0.5mm to 1mm. The first airflow channel 7 is a regular quadrilateral with a pore width of 5mm to 10mm. The second catalyst block 6 also has a surface length and width of 120mm to 200mm and a wall thickness of 0.5mm to 1mm. The second airflow channel 8 has a pore width of 5mm to 10mm. In this example, both the first catalyst block 5 and the second catalyst block 6 have a surface length and width of 150mm and a wall thickness of 0.9mm. The pore width of both the first airflow channel 7 and the second airflow channel 8 is 7.4mm.
[0037] like Figure 7 As shown, a denitrification device includes the aforementioned denitrification catalyst hybrid structure 11.
[0038] It also includes a flue 10, which is provided with at least one layer of denitrification catalyst hybrid structure 11. In this example, a three-layer structure is provided. The flat plate region 2 in the denitrification catalyst hybrid structure 11 is located on one side near the corner of the flue 10 and on the other side near the corner of the flue 10.
[0039] During implementation, by setting a honeycomb region 1 in the middle and a flat plate region 2 at the edge on the plate, the flue gas in different regions can undergo sufficient catalytic denitrification reaction. In addition, it can better resist the erosion of flue gas and extend the overall service life of the plate. By setting a denitrification device with a denitrification catalyst hybrid structure 11, the flue gas with uneven flow rate through the flue 10 can achieve a good denitrification effect. By making reasonable use of the characteristics of different catalyst structures, the performance requirements of catalysts at different positions in the flue 10 are matched, and the comprehensive utilization rate of catalysts is improved.
[0040] The above description is merely a specific example of this utility model and does not constitute any limitation on this utility model. Obviously, those skilled in the art, after understanding the content and principle of this utility model, may make various modifications and changes in form and details without departing from the principle and structure of this utility model. However, these modifications and changes based on the concept of this utility model are still within the protection scope of the claims of this utility model.
Claims
1. A denitrification catalyst hybrid structure, comprising plates for supporting the catalyst; characterized in that, The plate layer includes a honeycomb region (1) and a flat plate region (2); the honeycomb region (1) is provided with a plurality of first airflow channels (7) distributed in a regular polygonal shape, and the first airflow channels (7) are regularly distributed in the honeycomb region (1); the flat plate region (2) is provided with a plurality of second airflow channels (8) in the shape of strip holes, and the second airflow channels (8) are arranged in parallel in the flat plate region (2); the flat plate region (2) is located at the edge of the plate layer, and the honeycomb region (1) is located in the middle region of the plate layer.
2. The denitrification catalyst hybrid structure according to claim 1, characterized in that, The flat plate area (2) is located on the left and right sides of the cellular area (1).
3. The denitrification catalyst hybrid structure according to claim 2, characterized in that, The honeycomb region (1) occupies 40% to 80% of the surface area of the square plate.
4. The denitrification catalyst hybrid structure according to claim 3, characterized in that, Symmetrical flat plate areas (2) are provided on both sides of the honeycomb area (1), wherein one of the flat plate areas (2) occupies half of the remaining area of the plate surface after the honeycomb area (1).
5. The denitrification catalyst hybrid structure according to claim 1, characterized in that, Both the honeycomb region (1) and the flat plate region (2) are set as square cells (9) arranged in rows and columns; a first module (3) is set in the cell (9) of the honeycomb region (1), and a second module (4) is set in the cell (9) of the flat plate region (2); a first catalyst block (5) with a first airflow channel (7) is set in the first module (3), and a second catalyst block (6) with a second airflow channel (8) is set in the second module (4).
6. The denitrification catalyst hybrid structure according to claim 5, characterized in that, The length and width of the surface of the first catalyst block (5) are the same, ranging from 120mm to 200mm, and the wall thickness is from 0.5mm to 1mm; wherein the shape of the first airflow channel (7) is a regular quadrilateral, and the hole width is from 5mm to 10mm.
7. The denitrification catalyst hybrid structure according to claim 5, characterized in that, The length and width of the surface of the second catalyst block (6) are both 120mm~200mm, and the wall thickness is 0.5mm~1mm; the pore width of the second gas flow channel (8) is 5mm~10mm.
8. The denitrification catalyst hybrid structure according to claim 1, characterized in that, The material of the plate contains catalyst components.
9. A denitrification device, characterized in that, Includes the denitrification catalyst hybrid structure (11) as described in any one of claims 1 to 8.
10. A denitrification device according to claim 9, characterized in that, It also includes a flue (10), which is provided with at least one layer of denitrification catalyst hybrid structure (11); the flat plate area (2) in the denitrification catalyst hybrid structure (11) is located on one side of the corner of the flue (10) and on one side of the corner of the flue (10).