Rolling bed low-temperature catalytic reduction denitration system

Abstract

The utility model relates to a flue gas denitration treatment technology, in particular to a low-temperature catalytic reduction denitration system of a rolling bed. The rolling bed low-temperature catalytic reduction denitration system comprises an ammonia gas generating device and a rolling bed low-temperature catalytic denitration device, the rolling bed low-temperature catalytic denitration device is provided with a flue gas inlet and a flue gas outlet, and the rolling bed low-temperature catalytic denitration device is filled with a spheroidal low-temperature denitration catalyst. A catalyst flowing assembly is arranged in the rolling bed low-temperature catalytic denitration device, an ammonia gas outlet of the ammonia gas generating device is connected with the flue gas inlet through an ammonia gas conveying pipe, the flue gas inlet is further connected with a flue gas pipeline, and the flue gas outlet is connected with a flue gas exhaust pipe. The system has the advantages that the system is reasonable in design, the problem of denitration of flue gas at 130-200 DEG C can be effectively solved, and medium-high temperature SCR (selective catalytic reduction) can be replaced by combining an independent ammonia gas preparation system and a spheroidal low-temperature catalyst, so that the ultralow emission standard of NOx is realized.

Description

Technical Field

[0001] The utility model relates to a flue gas denitration treatment technology, in particular to a rolling bed low-temperature catalytic reduction denitration system. Background Art

[0002] At present, the problem of air pollution is still the focus of great concern of the whole society. The "Second National Pollution Source Census Bulletin" released in 2020 shows that among the three major pollutants that form haze, the annual emission of nitrogen oxides (NOx) is as high as 17.8522 million tons, which is nearly 1 million tons more than particulate matter and 2.5 times the emission of sulfur dioxide. Nitrogen oxides are one of the main causes of environmental problems such as ozone holes and photochemical smog. Therefore, reducing nitrogen oxide emissions has become a key demand for solving the haze problem.

[0003] Most of the NOx emitted by human activities comes from the combustion of fuels. More than 600,000 industrial furnaces in service in high-energy-consuming process industries such as steel, building materials, petrochemicals, and chemicals are major NOx emitters, accounting for about 30% of my country's total emissions. Currently, the NOx emission level of industrial furnaces using non-catalytic denitrification technologies is mostly between 200 and 500 mg / Nm 3 , and ultra-low emission standards (NOx < 50mg / Nm 3 ) There is a big gap. If the traditional catalytic reduction denitrification technology (medium and high temperature SCR technology) is used, since the flue gas emission temperature of this type of industrial furnace is generally low (<200℃), the traditional medium and high temperature SCR technology cannot be directly used for denitrification. It is necessary to add a GGH (tail gas reheating) system, which has a high investment cost and wastes a lot of high-quality heat energy. Therefore, the development of low-temperature catalytic reduction denitrification process technology is of great significance.

[0004] Based on this, it is necessary to develop a rolling bed low-temperature catalytic reduction denitrification system. Utility Model Content

[0005] The technical problem to be solved by the utility model is to provide a rolling bed low-temperature catalytic reduction denitration system, which effectively overcomes the defects of the prior art.

[0006] The technical solution of the utility model to solve the above technical problems is as follows:

[0007] A rolling bed low-temperature catalytic reduction denitration system comprises an ammonia generating device and a rolling bed low-temperature catalytic denitration device, wherein the rolling bed low-temperature catalytic denitration device comprises a flue gas inlet and a flue gas outlet, the rolling bed low-temperature catalytic denitration device is filled with a spherical low-temperature denitration catalyst, the rolling bed low-temperature catalytic denitration device is provided with a catalyst flow assembly, the ammonia outlet of the ammonia generating device is connected to the flue gas inlet via an ammonia delivery pipe, the flue gas inlet is also connected to a flue gas pipeline, and the flue gas outlet is connected to a smoke exhaust pipe.

[0008] On the basis of the above technical solution, the present invention can also be improved as follows.

[0009] Furthermore, a premixing box is provided at the flue gas inlet, and the ammonia gas delivery pipe and the flue gas pipeline are respectively connected to the premixing box.

[0010] Furthermore, a flow regulating valve is provided on the ammonia delivery pipe.

[0011] Furthermore, a booster delivery device is provided on the ammonia delivery pipe.

[0012] Furthermore, the above-mentioned booster conveying device is a fan.

[0013] Furthermore, the rolling bed low-temperature catalytic denitrification device includes a shell and a catalyst flow component arranged in the shell, the top of the shell is provided with a catalyst inlet that can be opened or closed, the side walls on opposite sides of the shell are respectively provided with the flue gas inlet and the flue gas outlet, and the flue gas inlet and the flue gas outlet are respectively provided with filter screens, and the bottom of the shell is provided with a catalyst discharge outlet that can be opened or closed.

[0014] Furthermore, the catalyst flow component includes a rotating shaft and a plurality of stirring rods. The rotating shaft is horizontally rotatably mounted between the two end side walls of the shell. The plurality of stirring rods are circumferentially spaced apart and mounted on the rotating shaft. A rotating drive device is disposed outside the side wall at one end of the shell. The rotating drive device is transmission-connected to one end of the rotating shaft.

[0015] Furthermore, the above-mentioned rotation driving device is a servo motor or a stepping motor.

[0016] Furthermore, a gate valve is provided at the catalyst discharge port.

[0017] Furthermore, the smoke exhaust pipe is connected to a waste heat recovery system.

[0018] The beneficial effects of the utility model are: the system design is reasonable, and it can effectively solve the denitrification problem of flue gas at 130°C to 200°C. Combined with an independent ammonia production system and a spherical low-temperature catalyst, it can replace medium and high-temperature SCR and achieve ultra-low NOx emission standards. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of an embodiment of a rolling bed low-temperature catalytic reduction denitration system of the utility model;

[0020] Figure 2 It is a structural schematic diagram of another embodiment of the rolling bed low-temperature catalytic reduction denitration system of the utility model;

[0021] Figure 3It is a structural schematic diagram of another embodiment of the rolling bed low-temperature catalytic reduction denitrification system of the utility model.

[0022] In the accompanying drawings, the components represented by the reference numerals are listed as follows:

[0023] 1. Ammonia generating device; 2. Rolling bed low-temperature catalytic denitrification device; 3. Catalyst flow assembly; 4. Ammonia delivery pipe; 5. Flue gas pipeline; 6. Smoke exhaust pipe; 7. Premixing box; 21. Casing; 31. Rotating shaft; 32. Stirring rod; 41. Flow regulating valve; 42. Booster delivery device; 211. Catalyst inlet; 212. Filter; 213. Catalyst outlet. DETAILED DESCRIPTION

[0024] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0025] Example: Figure 1 As shown, the rolling bed low-temperature catalytic reduction denitrification system of the present embodiment comprises an ammonia generating device 1 and a rolling bed low-temperature catalytic denitrification device 2, the rolling bed low-temperature catalytic denitrification device 2 having a flue gas inlet and a flue gas outlet, the rolling bed low-temperature catalytic denitrification device 2 being filled with a spherical low-temperature denitrification catalyst, the rolling bed low-temperature catalytic denitrification device 2 being provided with a catalyst flow component 3, the ammonia outlet of the ammonia generating device 1 being connected to the flue gas inlet via an ammonia delivery pipe 4, the flue gas inlet being also connected to a flue gas pipeline 5, and the flue gas outlet being connected to a smoke exhaust pipe 6.

[0026] The operation process is as follows:

[0027] The rolling bed low-temperature catalytic reduction denitration system of this embodiment is configured with an independent ammonia generator 1 for denitration (a product of the prior art, which will not be described in detail here), and the denitration process does not require other heat sources; a spherical low-temperature denitration catalyst (also a product of the prior art, in this embodiment, a conventional low-temperature denitration catalyst is prepared into a spherical shape) is used in the rolling bed low-temperature catalytic denitration device 2, and the catalyst flow component 3 in the rolling bed low-temperature catalytic denitration device 2 is cooperated to promote the low-temperature denitration catalyst to roll in the rolling bed low-temperature catalytic denitration device 2 (the rolling resistance is relatively small during the rolling process, and the spherical catalyst can be easily rolled in the denitration device in a timely manner); since the overall composition of the spherical catalyst is They are all catalyst materials. When the surface of the spherical catalyst is deactivated by other factors during the operation of the system, the spherical low-temperature denitration catalyst can be rolled in the device through the catalyst flow component 3 inside the rolling bed low-temperature catalytic denitration device 2. The surfaces of the low-temperature denitration catalyst rub against each other during the rolling process, and the deactivated catalyst on the surface of the low-temperature denitration catalyst is worn off, so that the low-temperature denitration catalyst becomes a new catalyst again. When the catalyst worn off by the spherical body reaches a certain amount, new catalyst particles can be added to the rolling bed low-temperature catalytic denitration device 2, and the failed catalyst particles can be replaced, which fully realizes the online replacement of the catalyst of the low-temperature denitration device and realizes the long-term, safe, stable and economical operation of the low-temperature denitration device. The whole system is reasonably designed and can effectively solve the denitration problem of flue gas at 130℃~200℃. Combined with the independent ammonia production system and the spherical low-temperature catalyst, it can replace the medium and high temperature SCR and achieve the ultra-low NOx emission standard.

[0028] As a preferred embodiment, Figure 2 As shown, a premixing box 7 is provided at the flue gas inlet, and the ammonia delivery pipe 4 and the flue gas pipeline 5 are connected to the premixing box 7 respectively.

[0029] In the above embodiment, a premixing box 7 is provided before the flue gas enters, so that the flue gas and ammonia are mixed in advance and then enter the rolling bed low-temperature catalytic denitrification device 2 for denitrification reaction, which can promote the reaction to a certain extent.

[0030] In this embodiment, a flow regulating valve 41 is provided on the ammonia delivery pipe 4. The flow regulating valve 41 is used to adjust the flow rate of the ammonia delivery pipe 4, that is, to adjust the reaction ratio of ammonia and flue gas to ensure efficient reaction.

[0031] In this embodiment, a booster delivery device 42 is provided on the ammonia delivery pipe 4. The booster delivery device 42 ensures good delivery of ammonia to the rolling bed low-temperature catalytic denitration device 2.

[0032] In this embodiment, the booster conveying device 42 may be a conventional fan, and its specific model is selected according to actual needs, which will not be described in detail here.

[0033] As a preferred embodiment, the rolling bed low-temperature catalytic denitrification device 2 includes a shell 21 and a catalyst flow component 3 arranged in the shell 21, the top of the shell 21 is provided with a catalyst inlet 211 that can be opened or closed, the side walls on opposite sides of the shell 21 are respectively provided with the flue gas inlet and the flue gas outlet, and the flue gas inlet and the flue gas outlet are respectively provided with filter screens 212, and the bottom of the shell 21 is provided with a catalyst discharge port 213 that can be opened or closed.

[0034] In the above embodiment, the flue gas and ammonia enter through the flue gas inlet on one side of the shell 21, undergo catalytic reaction through the spherical low-temperature denitration catalyst inside the shell 21, and then are discharged through the flue gas outlet on the other side of the shell 21. The entire pipeline design is relatively reasonable, adapted to the flow direction of the flue gas, and the overall structural design is relatively simple. In addition, the design of the filter screen 212 at the flue gas inlet and the flue gas outlet enables the low-temperature denitration catalyst to be well filled inside the shell 21. When the catalyst needs to be replaced, the catalyst outlet 213 at the bottom of the shell 21 is opened, and a new catalyst can be added from the catalyst inlet 211 at the top at the same time, so as to realize online replacement of the catalyst. The worn catalyst is collected by the recovery system adapted to the bottom of the rolling bed low-temperature catalytic denitration device 2, and then returned to the catalyst production workshop for regeneration and recycling. The entire design effectively solves the problem that the low-temperature catalyst is easily deactivated by different flue gas components, and can ensure the long-term safe and stable operation of the low-temperature catalytic reduction denitration system.

[0035] As a preferred embodiment, the catalyst flow component 3 includes a rotating shaft 31 and a plurality of stirring rods 32. The rotating shaft 31 is horizontally rotatably mounted between the two end side walls of the outer shell 21. The plurality of stirring rods 32 are respectively mounted on the rotating shaft 31 at circumferential intervals. A rotating drive device is provided outside the side wall of one end of the outer shell 21. The rotating drive device is transmission-connected to one end of the rotating shaft 31.

[0036] In the above embodiment, the rotary drive device drives the rotating shaft 31 extending from one end of the outer shell 21 to rotate from the outside of the outer shell 21, thereby driving the multiple groups of stirring rods 32 on the rotating shaft 31 to rotate, and then stirring the low-temperature denitration catalyst filled in the inner part of the outer shell 21 to roll, and the friction between them can remove the ineffective surface part, so that the catalyst can resume the catalytic effect. Its structural design is simple and easy to use.

[0037] In this embodiment, the above-mentioned rotation drive device adopts an existing servo motor or a stepper motor. During actual use, the model can be flexibly adapted according to needs, and no further details are given here.

[0038] In this embodiment, a gate valve is provided at the catalyst outlet 213. The catalyst outlet 213 is opened and closed by opening the gate valve.

[0039] In this embodiment, the bottom wall of the housing 21 may be designed to be conical, and a catalyst discharge port 213 is provided in the middle of the bottom wall.

[0040] As a preferred embodiment, Figure 3 As shown, the smoke exhaust pipe 6 is connected to a waste heat recovery system.

[0041] In the above embodiment, heat is exchanged with the exhaust gas in the smoke exhaust pipe 6 through the waste heat recovery system to fully recover heat, which is more environmentally friendly.

[0042] In this embodiment, the preheat recovery system may use a conventional waste heat recovery heat exchanger, such as a plate heat exchanger.

[0043] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0044] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present utility model, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0045] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0046] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0047] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0048] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A rolling bed low temperature catalytic reduction denitration system, characterized in that: The invention comprises an ammonia generating device (1) and a rolling bed low-temperature catalytic denitration device (2), wherein the rolling bed low-temperature catalytic denitration device (2) has a flue gas inlet and a flue gas outlet, the rolling bed low-temperature catalytic denitration device (2) is filled with a spherical low-temperature denitration catalyst, the rolling bed low-temperature catalytic denitration device (2) is provided with a catalyst flow component (3), the ammonia outlet of the ammonia generating device (1) is connected to the flue gas inlet via an ammonia delivery pipe (4), the flue gas inlet is also connected to a flue gas pipeline (5), and the flue gas outlet is connected to a smoke exhaust pipe (6).

2. A rolling bed low temperature catalytic reduction denitration system according to claim 1, characterized in that: The flue gas inlet is connected to a premixing box (7), and the ammonia delivery pipe (4) and the flue gas pipeline (5) are respectively connected to the premixing box (7).

3. A rolling bed low temperature catalytic reduction denitration system according to claim 1, characterized in that: The ammonia delivery pipe (4) is provided with a flow regulating valve (41).

4. A rolling bed low temperature catalytic reduction denitration system according to claim 3, characterized in that: The ammonia delivery pipe (4) is provided with a pressurizing delivery device (42).

5. A rolling bed low temperature catalytic reduction denitration system according to claim 4, characterized in that: The pressurized conveying device (42) is a fan.

6. The rolling bed low temperature catalytic reduction denitration system according to claim 1, characterized in that: The rolling bed low-temperature catalytic denitration device (2) comprises a shell (21) and a catalyst flow assembly (3) arranged in the shell (21); the top of the shell (21) is provided with a catalyst inlet (211) that can be opened or closed; the side walls on opposite sides of the shell (21) are respectively provided with the flue gas inlet and the flue gas outlet, and the flue gas inlet and the flue gas outlet are respectively provided with filter screens (212); the bottom of the shell (21) is provided with a catalyst discharge outlet (213) that can be opened or closed.

7. A rolling bed low temperature catalytic reduction denitration system according to claim 6, characterized in that: The catalyst flow component (3) comprises a rotating shaft (31) and a plurality of groups of stirring rods (32); the rotating shaft (31) is horizontally rotatably mounted between the two end side walls of the outer shell (21); the plurality of groups of stirring rods (32) are respectively mounted on the rotating shaft (31) at intervals along the circumferential direction; a rotating drive device is provided outside the side wall at one end of the outer shell (21); the rotating drive device is drivingly connected to one end of the rotating shaft (31).

8. A rolling bed low temperature catalytic reduction denitration system according to claim 7, characterized in that: The rotation driving device is a servo motor or a stepping motor.

9. A rolling bed low temperature catalytic reduction denitration system according to claim 6, characterized in that: A gate valve is provided at the catalyst discharge port (213).

10. A rolling bed low temperature catalytic reduction denitration system according to any one of claims 1 to 9, characterized in that: The smoke exhaust pipe (6) is connected to a waste heat recovery system.

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