Flue gas oxidation denitrification device and method

Abstract

The present invention provides a flue gas oxidation denitrification device and method. The flue gas oxidation denitrification device comprises an oxidation chamber and an absorption chamber connected to the oxidation chamber; an oxidation liquid spraying device is provided in the oxidation chamber, and an absorption liquid spraying device is provided in the absorption chamber; a flue gas turbulence device is provided in at least one of the oxidation chamber and the absorption chamber; when the oxidation chamber is provided with a flue gas turbulence device, the flue gas turbulence device of the oxidation chamber is used to increase the degree of turbulence of the flue gas entering the oxidation chamber in the oxidation chamber; when the absorption chamber is provided with a flue gas turbulence device, the flue gas turbulence device of the absorption chamber is used to increase the degree of turbulence of the flue gas entering the absorption chamber in the absorption chamber. The method for using the device to perform flue gas oxidation denitrification treatment comprises the steps of using sodium hypochlorite solution as an oxidant to oxidize nitrogen oxides in the flue gas under the action of the turbulence device when the flue gas enters the oxidation chamber and / or using alkaline absorption liquid to remove NOx and other acid gases in the flue gas under the action of the turbulence device when the oxidized flue gas enters the absorption chamber.

Description

Technical Field

[0001] The invention belongs to the technical field of flue gas denitration, and relates to a flue gas oxidation denitration device and method. Background Art

[0002] Nitrogen oxides (NOx) are mainly nitric oxide (NO) and nitrogen dioxide (NO2). When their content and existence time in the atmosphere reach a level that has a harmful effect on humans, animals, plants and other substances, pollution will form. There are other forms of nitrogen oxides in the atmosphere, such as nitrous oxide (N2O) and nitrogen trioxide (N2O3).

[0003] NO can react with ozone in the atmosphere to form NO2 very quickly. The rate at which NO reacts directly with oxygen to form NO2 depends mainly on the concentration of NO and the ambient temperature. 3 Under the condition of , 10% of NO is oxidized to NO2 in 1.5 hours, and 50% of NO is oxidized to NO2 in 10.75 hours. 3 Under the conditions of , it takes more than 8 hours for 10% of NO to be oxidized to NO2. It can be seen that when the NO content in the air is very low, it can remain in the air for a long time. NO can also react with NO2 to form nitrogen trioxide (N2O3), but the amount formed is very small and has little impact on the quality of the atmosphere. NO2 is the most important light-absorbing molecule in the lower atmosphere and can absorb visible light and ultraviolet light from solar radiation. It absorbs ultraviolet light with a wavelength of less than 400 nanometers and is decomposed into NO and oxygen atoms, especially under the irradiation of light with a wavelength of 300-370 nanometers, more than 90% of NO2 molecules can be decomposed; because the bond energy of the chemical bond between the oxygen atom and NO in NO2 (73 cal / mol) is greater than the photon energy with a wavelength of 400 nanometers, NO2 does not decompose when exposed to visible light with a wavelength greater than 420 nanometers. Most of the NOx in the atmosphere is eventually converted into nitrate particles and disappears from the atmosphere through processes such as wet deposition or dry deposition. N2O is an inert gas that can remain in the atmosphere for a long time. After entering the stratosphere, it can react with ozone and decompose.

[0004] GB13223-2011 "Emission Standards of Air Pollutants from Thermal Power Plants" stipulates that the NOx emission standard for newly built boilers is 100 mg / m 3, increasingly stringent emission standards have prompted the continuous introduction of new denitrification technologies. Over the past decade, in order to achieve low-temperature flue gas oxidation, researchers at home and abroad have tried O3, H2O2, KMnO4, and NaClO2 to address the shortcomings of SCR and SNCR technologies in industrial boiler flue gas denitrification. Among them, NaClO2 has the best NOx removal ability as an oxidant. Related research is mainly based on theoretical analysis and flue gas simulation experiments, and there has been no report on practical application. Summary of the invention

[0005] The object of the present invention is to provide a highly efficient flue gas oxidation denitrification device and method.

[0006] In order to achieve the above-mentioned object, the present invention provides a flue gas oxidation denitration device, wherein the device comprises an oxidation chamber and an absorption chamber (i.e., a denitration chamber) connected to the oxidation chamber; the flue gas oxidized in the oxidation chamber enters the absorption chamber for absorption;

[0007] The oxidation chamber is provided with an oxidation liquid spraying device, and the absorption chamber is provided with an absorption liquid spraying device;

[0008] At least one of the oxidation chamber and the absorption chamber is provided with a flue gas turbulence device;

[0009] When the oxidation chamber is provided with a flue gas turbulence device, the flue gas turbulence device of the oxidation chamber is used to increase the degree of turbulence of the flue gas entering the oxidation chamber in the oxidation chamber;

[0010] When the absorption chamber is provided with a smoke turbulence device, the smoke turbulence device of the absorption chamber is used to increase the turbulence degree of the smoke entering the absorption chamber in the absorption chamber.

[0011] In the above-mentioned flue gas oxidation denitrification device, the flue gas enters the oxidation chamber to oxidize the nitrogen oxides in the flue gas. The flue gas after oxidation treatment in the oxidation chamber enters the absorption chamber to absorb the nitrogen oxides in the flue gas and realize denitrification treatment; the flue gas turbulence equipment belt increases the degree of flue gas turbulence, realizes full contact between the flue gas and the oxidizing liquid and / or the absorbing liquid, and realizes efficient oxidation denitrification of the flue gas.

[0012] In the above flue gas oxidation and denitrification device, preferably, the flue gas turbulence device of the oxidation chamber includes a partition that divides the oxidation chamber into at least two chambers from top to bottom and a central column that runs through the entire oxidation chamber from top to bottom; each chamber of the oxidation chamber is connected to the central column through a grille arranged on the central column, and the central column is a hollow structure, which realizes the connection between the chambers; each chamber is provided with the oxidation liquid spraying device, and the flue gas inlet of the oxidation chamber is arranged at the bottom chamber. The flue gas enters the bottom chamber from the flue gas inlet, contacts the oxidation liquid sprayed by the oxidation liquid spraying device, forms a cyclone in the bottom chamber to increase the contact time, and then the flue gas enters the central column. After the flue gas is accelerated in the column, it is ejected from the central column grille in the upper chamber into the upper chamber, which greatly increases the degree of turbulence of the flue gas in the upper chamber, and the flue gas entering the upper chamber is more fully mixed with the oxidation liquid sprayed by the oxidation liquid spraying device, so as to realize efficient oxidation of the flue gas. In a specific embodiment, each part of the central column located in each chamber of the oxidation chamber is provided with at least one grille.

[0013] In the above flue gas oxidation denitrification device, preferably, the flue gas turbulence device of the absorption chamber includes a partition that divides the absorption chamber from top to bottom into at least two chambers and a central column that runs through the entire absorption chamber from top to bottom; each chamber of the absorption chamber is connected to the central column through a grid arranged on the central column, and the central column is a hollow structure, which realizes the connection between the chambers; each chamber is provided with the absorption liquid spraying device, and the absorption chamber flue gas inlet is arranged at the bottom chamber. The flue gas enters the bottom chamber from the flue gas inlet, contacts the absorption liquid sprayed by the absorption liquid spraying device, forms a cyclone in the bottom chamber to increase the contact time, and then the flue gas enters the central column. After the flue gas is accelerated in the column, it is ejected from the central column grid in the upper chamber into the upper chamber, which greatly increases the degree of turbulence of the flue gas in the upper chamber, and the flue gas entering the upper chamber is more fully mixed with the absorption liquid sprayed by the absorption liquid spraying device, so as to realize efficient absorption of the flue gas and complete the oxidation denitrification treatment. In a specific embodiment, each part of the central column located in each chamber of the absorption chamber is provided with at least one grid.

[0014] In the above flue gas oxidation denitration device, preferably, the device is further provided with an oxidation liquid circulation system, the oxidation liquid circulation system comprises an oxidation liquid pool provided in the oxidation chamber and a circulation device connected to the oxidation liquid pool, the oxidation liquid pool is used to collect the oxidation liquid after the flue gas treatment in the oxidation chamber, and the circulation device is used to transport the oxidation liquid collected in the oxidation liquid pool to the oxidation liquid spraying device for recycling; more preferably, the oxidation liquid pool is provided with an oxidation liquid pool stirring paddle. The circulation device can be a circulation pump.

[0015] In the above flue gas oxidation denitration device, preferably, the device is further provided with an absorption liquid circulation system, the absorption liquid absorption system comprises an absorption liquid pool arranged in the absorption chamber and a circulation device connected to the absorption liquid pool, the absorption liquid pool is used to collect the absorption liquid after the flue gas treatment in the absorption chamber, and the circulation device is used to transport the absorption liquid collected in the absorption liquid pool to the absorption liquid spraying device for recycling. The circulation device can be a circulation pump.

[0016] In the above-mentioned flue gas oxidation denitrification device, preferably, the absorption chamber and the oxidation chamber are arranged in the same absorption tower, and the oxidation chamber is located at the lower part of the absorption chamber.

[0017] In a specific embodiment, the flue gas oxidation denitration device comprises a denitration tower body, in which an oxidation chamber and an absorption chamber connected to the oxidation chamber are arranged, the oxidation chamber is located at the lower part of the absorption chamber, and the flue gas enters the absorption chamber for absorption after being oxidized by the oxidation chamber, and then is discharged from the denitration tower body through the flue gas outlet;

[0018] An oxidizing liquid spraying device and a flue gas turbulence device are provided in the oxidation chamber; the flue gas turbulence device of the oxidation chamber includes a partition that divides the oxidation chamber into two upper and lower chambers and a central column that runs through the entire oxidation chamber from top to bottom; each chamber of the oxidation chamber is connected to the central column through a grid arranged on the central column, and the central column is a hollow structure, which realizes the connection between the chambers (preferably, each part of the central column located in each chamber of the absorption chamber is provided with at least one grid); each chamber is provided with the oxidizing liquid spraying device, and the flue gas inlet of the denitrification tower body is arranged in the bottom chamber of the oxidation chamber; the flue gas enters the oxidation chamber to realize the oxidation of nitrogen oxides in the flue gas;

[0019] An absorption liquid spraying device and a flue gas turbulence device are provided in the absorption chamber. The flue gas turbulence device of the absorption chamber includes a partition that divides the absorption chamber into two upper and lower chambers and a central column that runs through the entire absorption chamber from top to bottom; each chamber of the absorption chamber is connected to the central column through a grid arranged on the central column, and the central column is a hollow structure, which realizes the connection between the chambers (preferably, each part of the central column located in each chamber of the absorption chamber is provided with at least one grid); each chamber is provided with the absorption liquid spraying device; the flue gas after oxidation treatment in the oxidation chamber enters the absorption chamber from the bottom chamber of the absorption chamber to realize the absorption of nitrogen oxides in the flue gas;

[0020] The denitrification tower body is further provided with a dual circulation system, namely an oxidizing liquid circulation system and an absorption liquid circulation system; the oxidizing liquid circulation system comprises an oxidizing liquid pool arranged in the oxidation chamber and a circulation device (such as a circulation pump) connected to the oxidizing liquid pool, the oxidizing liquid pool is used to collect the oxidizing liquid after the flue gas in the oxidation chamber is treated, and the circulation device is used to transport the oxidizing liquid collected in the oxidizing liquid pool to the oxidizing liquid spraying device for recycling; preferably, an oxidizing liquid pool stirring paddle is provided in the oxidizing liquid pool; the absorption liquid absorption system comprises an absorption liquid pool arranged in the absorption chamber and a circulation device (such as a circulation pump) connected to the absorption liquid pool, the absorption liquid pool is used to collect the absorption liquid after the flue gas in the absorption chamber is treated, and the circulation device is used to transport the absorption liquid collected in the absorption liquid pool to the absorption liquid spraying device for recycling.

[0021] In the flue gas oxidation denitration device provided in the above specific embodiment, the flue gas enters the denitration tower from the bottom chamber of the oxidation chamber and contacts the oxidizing liquid in reverse. The oxidizing liquid passes through the oxidizing liquid spraying device into the oxidation chamber to react with the flue gas. The flue gas first enters the lower chamber of the partition, and the flue gas contacts the oxidizing liquid (such as NaClO2), forming a cyclone in the area to increase the contact time. Then the flue gas enters the central column and accelerates, and then jets out from the partition grid of the upper chamber of the central column into the upper chamber, greatly increasing the degree of disorder of the flue gas in the upper chamber, so that the flue gas and the oxidizing liquid are more fully mixed, and efficient oxidation of the flue gas is achieved. After oxidation in the oxidation chamber, NO in the flue gas is fully oxidized and converted into NO2, and enters the absorption chamber with a small amount of Cl2, HCl and untreated or unremoved SO2. The flue gas entering the absorption chamber contacts the alkaline absorption liquid in reverse, and also fully reacts with the flue gas through the central column-grid structure. Various pollutants including NOx can be almost completely removed here. In addition, the flue gas oxidation denitration device provided in the above specific embodiment adopts a single-tower dual-circulation operation mode. During the oxidation denitration process, the absorption liquid and the oxidation liquid are sprayed in different sections of the same tower, and the relatively independent circulation systems in the oxidation chamber and the denitration chamber realize the recycling of the absorption liquid and the oxidation liquid. In addition, the single-tower dual-circulation can effectively reduce the footprint of the device.

[0022] In the above-mentioned flue gas oxidation denitrification device, preferably, an oxidizing liquid spraying device is provided on the top of the central column of the oxidation chamber, and the flue gas is accelerated in the central column and can be further oxidized by the oxidizing liquid.

[0023] In the above-mentioned flue gas oxidation denitrification device, preferably, an absorption liquid spraying device is provided on the top of the central column of the absorption chamber, and the flue gas is accelerated in the central column and can be further oxidized by the absorption liquid.

[0024] In the above flue gas oxidation denitrification device, preferably, the radius of the oxidation chamber is approximately 3-5 times the radius of the central column of the oxidation chamber.

[0025] In the above flue gas oxidation denitrification device, preferably, the radius of the absorption chamber is approximately 3-5 times the radius of the central column of the absorption chamber.

[0026] In the above flue gas oxidation denitration device, preferably, the radius of the central column of the oxidation chamber is equal to the radius of the central column of the absorption chamber. The radius of the central column of the oxidation chamber is equal to the radius of the central column of the absorption chamber, which can better avoid the occurrence of excessive compression of flue gas in the central column.

[0027] In the above flue gas oxidation denitration device, preferably, the radius of the oxidation chamber is equal to the radius of the absorption chamber. The radius of the oxidation chamber is equal to the radius of the absorption chamber for ease of processing and transportation.

[0028] In the above flue gas oxidation denitration device, preferably, the grid opening rate (grid opening rate is the percentage of grid opening area to total grid area) on the central column of the oxidation chamber is 50%-75%.

[0029] In the above flue gas oxidation denitration device, preferably, the grid opening rate (grid opening rate is the percentage of grid opening area to total grid area) on the central column of the absorption chamber is 50%-75%.

[0030] In the above flue gas oxidation denitrification device, preferably, the grid spacing on the central column of the oxidation chamber is 0.05R-0.1R, and R is the radius of the central column.

[0031] In the above flue gas oxidation denitration device, preferably, the grid spacing on the central column of the absorption chamber is 0.05R-0.1R, and R is the radius of the central column.

[0032] In the above-mentioned flue gas oxidation denitrification device, preferably, the oxidizing liquid spraying equipment includes a spray grid; more preferably, the spray grid includes a nozzle and a water delivery frame structure; further preferably, the spray grid is formed by a circular frame nozzle connected to the bottom end of the frame.

[0033] In the above-mentioned flue gas oxidation denitrification device, preferably, the absorption liquid spraying equipment includes a spray grid; more preferably, the spray grid includes a nozzle and a water delivery frame structure; further preferably, the spray grid is formed by a circular frame nozzle connected to the bottom end of the frame.

[0034] In the above-mentioned flue gas oxidation denitrification device, preferably, the oxidizing liquid sprayed by the oxidizing liquid spraying equipment is a NaClO2 solution; more preferably, the concentration of NaClO2 in the NaClO2 solution is 1mmol / L-10mmol / L.

[0035] In the above flue gas oxidation denitration device, preferably, the absorption liquid sprayed by the absorption liquid spraying device is an alkaline solution; more preferably, the alkaline solution includes at least one of a NaOH solution, an ammonia solution, a urea solution, and a NaS2O8 solution. Using an alkaline solution as an absorbent, pollutants such as Cl2 and HCl generated during the oxidation process can be effectively removed, avoiding secondary pollution.

[0036] In the above flue gas oxidation denitration device, preferably, the device further includes a demister for treating the flue gas treated by the absorption chamber. When the absorption chamber and the oxidation chamber are arranged in the same absorption tower, the demister is preferably arranged between the absorption chamber and the flue gas outlet. The humidity of the flue gas treated by the absorption liquid spray is high, and a large amount of white smoke will be generated by direct discharge. The demister is arranged at the upper end of the denitration section, which can effectively reduce the water content of the flue gas, and the purified flue gas is discharged through the flue gas outlet.

[0037] In the above flue gas denitrification device, preferably, the device further comprises a NOx concentration detection device for detecting the NOx concentration in the flue gas after the oxidative denitrification treatment. More preferably, the device further comprises a flue gas circulation treatment device for passing the flue gas that fails the NOx concentration inspection into the oxidation chamber for re-oxidative denitrification of the flue gas.

[0038] In the above-mentioned flue gas denitrification device, the flue gas is oxidized in the oxidation chamber, and the NO in the flue gas is fully oxidized and converted into NO2, accompanied by a small amount of Cl2, HCl and untreated or uncleanly removed SO2 entering the absorption chamber; the flue gas in the absorption chamber is in countercurrent contact with the alkaline absorption liquid, and various pollutants including NOx are almost completely removed in the absorption chamber.

[0039] In the above-mentioned flue gas denitrification device, fillers such as Raschig rings and Pall rings can be appropriately arranged in the oxidation chamber and the absorption chamber to increase the contact area between the gas and liquid phases.

[0040] The present invention also provides a method for flue gas oxidation and denitrification treatment using the above-mentioned flue gas oxidation and denitrification device, wherein the method includes the steps of the flue gas entering an oxidation chamber, using a sodium hypochlorite solution as an oxidant to achieve oxidation of nitrogen oxides in the flue gas under the action of a turbulent flow device, and / or the step of the oxidized flue gas entering an absorption chamber, using an alkaline absorption liquid to achieve removal of NOx and other acidic gases in the flue gas under the action of a turbulent flow device.

[0041] In a specific embodiment, the above-mentioned flue gas oxidation denitrification treatment method includes: the flue gas enters the oxidation chamber and uses sodium hypochlorite solution as an oxidant to achieve oxidation of nitrogen oxides in the flue gas under the action of a turbulent flow device; the oxidized flue gas enters the absorption chamber and uses an alkaline absorption liquid to achieve removal of NOx and other acidic gases in the flue gas, thereby completing the steps of flue gas oxidation denitrification treatment.

[0042] In a specific embodiment, the above-mentioned flue gas oxidation denitrification treatment method includes: the flue gas enters the oxidation chamber and uses sodium hypochlorite solution as an oxidant to oxidize nitrogen oxides in the flue gas, and the oxidized flue gas enters the absorption chamber and uses alkaline absorption liquid under the action of turbulent flow equipment to remove NOx and other acidic gases in the flue gas, thereby completing the flue gas oxidation denitrification treatment steps.

[0043] In a specific embodiment, the above-mentioned flue gas oxidation denitrification treatment method includes: the flue gas enters the oxidation chamber and uses sodium hypochlorite solution as an oxidant to achieve oxidation of nitrogen oxides in the flue gas under the action of a turbulent flow device; the oxidized flue gas enters the absorption chamber and uses an alkaline absorption liquid to achieve removal of NOx and other acidic gases in the flue gas under the action of a turbulent flow device, thereby completing the steps of flue gas oxidation denitrification treatment.

[0044] In the above method, preferably, the method further comprises performing a demisting treatment on the flue gas treated with the absorption liquid.

[0045] In the above method, preferably, the method further comprises detecting the NOx concentration of the flue gas after the oxidation denitrification treatment, and the flue gas whose NOx concentration does not meet the emission standard re-enters the oxidation denitrification device for secondary oxidation denitrification.

[0046] In the above method, preferably, the sodium hypochlorite solution used for oxidation treatment is recycled.

[0047] In the above method, preferably, the alkaline solution used in the absorption treatment is recycled.

[0048] In flue gas purification, SCR method is often used for denitration. For flue gas with complex components and high dust content such as coke oven flue gas, if dust removal and desulfurization are not carried out first, the flue gas will have an adverse effect on the denitration catalyst, which may greatly reduce the life of the catalyst. The catalyst is expensive, which greatly increases the cost. The present invention adopts NaClO2 oxidation method, and greatly improves its denitration capacity and reduces the secondary pollution such as Cl2 and HCl generated by it by spraying alkali liquid. At the same time, turbulent flow equipment is introduced into the equipment to increase the reaction efficiency of the spray liquid and the flue gas, so that the denitration efficiency is significantly improved.

[0049] Compared with the prior art, the present invention has the following advantages:

[0050] 1. The flue gas denitrification device provided by the present invention introduces a turbulent flow device to increase the reaction efficiency of the spray liquid and the flue gas, and can be well applied to the denitrification treatment using NaClO2 as an oxidant.

[0051] 2. The method for oxidative denitration of flue gas provided by the present invention uses NaClO2 as an oxidant for denitration and cooperates with the turbulent flow equipment of the denitration device to achieve full oxidation treatment of the flue gas.

[0052] 3. The method for oxidative denitrification of flue gas provided by the present invention adopts alkaline solution as the absorption liquid in combination with the turbulent flow equipment of the denitrification device to achieve sufficient absorption and treatment of nitrogen oxides in the flue gas. At the same time, it has a good removal effect on sulfur-containing oxides in the flue gas, which is more conducive to the integration of fine desulfurization, desulfurization and denitrification. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 Schematic diagram of the flue gas oxidation denitrification device provided in Example 1.

[0054] Figure 2 Schematic diagram of the flue gas oxidation denitrification device provided for Comparative Example 1.

[0055] Figure 3A is NO in Experimental Example 1 X Remove the result map.

[0056] Figure 3B This is the NO oxidation rate result diagram in Experimental Example 1. DETAILED DESCRIPTION

[0057] In order to have a clearer understanding of the technical features, purposes and beneficial effects of the present invention, the technical solution of the present invention is now described in detail below, but it should not be construed as limiting the applicable scope of the present invention.

[0058] Example 1

[0059] This embodiment provides a flue gas oxidation denitrification device (such as Figure 1 As shown), the device comprises a denitration tower body 1 and a NOx concentration detection device 5. The denitration tower body 1 is provided with an oxidation chamber 2, an absorption chamber 3 connected to the oxidation chamber, and a demister 4 connected to the absorption chamber 3 from bottom to top. The denitration tower body 1 is provided with a flue gas inlet 11 at the bottom and a flue gas outlet 12 at the top. The NOx concentration detection device 5 is connected to the flue gas outlet 12;

[0060] The oxidation chamber 2 is provided with an oxidation liquid spraying device 21 and a flue gas turbulence device; the flue gas turbulence device of the oxidation chamber includes a partition 22 that divides the oxidation chamber 2 into two upper and lower chambers and a central column 23 that runs through the entire oxidation chamber 2 from top to bottom; the radius of the central column 23 is 1 / 5 of the radius of the oxidation chamber 2, and the portion of the central column 23 located in each chamber is provided with at least one central column grille 24, the interval of the central column grille 24 on the central column 23 is 0.1R, the height of each grille is 0.06R, R is the radius of the central column 23 (that is, 60% of the surface area of ​​the central column 23 is the central column grille 24), and the opening rate of the central column grille 24 is 70% ( The average opening rate of the entire central column 23 is 42%, that is, the total area of ​​the openings of all the central column grids 24 on the entire central column 23 accounts for 42% of the total area of ​​the central column 23); each chamber is connected to the central column 23 through the central column grid 24, and the central column 23 is a hollow structure, so as to achieve communication between the chambers; each chamber is provided with the oxidizing liquid spraying device 21, and the top of the central column 23 is provided with the oxidizing liquid spraying device 21; the flue gas inlet 11 of the denitrification tower body 1 is provided in the bottom chamber of the oxidation chamber 2; the oxidizing liquid spraying device 21 uses a spraying grid, which is formed by connecting a plurality of circular frame nozzles to the bottom end of the water delivery frame structure;

[0061] The absorption chamber 3 is provided with an absorption liquid spraying device 31 and a smoke turbulence device. The smoke turbulence device of the absorption chamber includes a partition 32 that divides the absorption chamber into two upper and lower chambers and a central column 33 that runs through the entire absorption chamber from top to bottom; the radius of the central column 33 is 1 / 5 of the radius of the absorption chamber 3, and the portion of the central column 33 located in each chamber is provided with at least one central column grille 34, the interval of the central column grille 34 on the central column 33 is 0.1R, the height of each grille is 0.07R, R is the radius of the central column 33 (that is, 70% of the surface area of ​​the central column 33 is the central column grille 34), and the opening rate of the central column grille 34 is 75% (the average opening rate of the entire central column 33 is 52.5%, that is, the entire central column 3 3, the total area of ​​the openings of all the central column grids 34 accounts for 52.5% of the total area of ​​the central column 33); each chamber is connected to the central column 33 through the central column grid 34, and the central column 33 is a hollow structure, so as to realize the connection between the chambers; each chamber is provided with the absorption liquid spraying device 31, and the top of the central column 33 is provided with an oxidation liquid spraying device 31; the absorption liquid spraying device 31 uses a spray grid, which is formed by connecting a plurality of circular frame nozzles to the bottom end of the water delivery frame structure; the flue gas after oxidation treatment in the oxidation chamber 2 enters the absorption chamber 3 from the bottom chamber of the absorption chamber 3 to absorb the nitrogen oxides in the flue gas; the absorption chamber 3 has the same radius as the oxidation chamber 2, and the radius of the central column 23 is the same as that of the central column 33;

[0062] The denitration tower body 1 is provided with a double circulation system, which is an oxidation liquid circulation system and an absorption liquid circulation system;

[0063] The oxidizing liquid circulation system includes an oxidizing liquid pool 25 disposed in the oxidation chamber and a circulation pump 26 connected to the oxidizing liquid pool. The oxidizing liquid pool 25 is used to collect the oxidizing liquid after the flue gas treatment in the oxidation chamber 2. The circulation pump 26 is used to transport the oxidizing liquid collected in the oxidizing liquid pool 25 to the oxidizing liquid spraying device 21 for recycling. The oxidizing liquid pool is provided with an oxidizing liquid pool stirring paddle 27 and a waste liquid discharge port 28.

[0064] The absorption liquid absorption system includes an absorption liquid pool 35 disposed in the absorption chamber 3, an absorption liquid storage pool 37 connected to the absorption liquid pool 35, and a circulation pump 36. The absorption liquid pool 35 is used to collect the absorption liquid after the flue gas treatment in the absorption chamber 3. The absorption liquid collected in the absorption liquid pool 35 is discharged into the absorption liquid storage pool 37. The circulation pump 36 is used to transport the absorption liquid in the absorption liquid storage pool 37 to the absorption liquid spraying device 31 for recycling. The absorption liquid storage pool 37 is provided with an absorption liquid stirring paddle 38.

[0065] The demister 4 is used to treat the flue gas after being treated by the absorption chamber 3;

[0066] NOx concentration detection device 5, the NOx concentration detection device 5 includes a three-way control valve and a NOx concentration detection probe, the three-way control valve is respectively connected to the flue gas outlet 12, the flue gas inlet 11 of the denitrification tower body 1, and the atmosphere; it is used to detect the NOx concentration in the flue gas after oxidation denitrification treatment discharged from the flue gas outlet 12, and to discharge the flue gas that has passed the NOx concentration inspection by controlling the connection state of the three-way control valve, and to re-enter the denitrification tower body 1 through the flue gas inlet 11 of the denitrification tower body 1 for secondary flue gas oxidation denitrification treatment;

[0067] Among them, the oxidizing liquid sprayed by the oxidizing liquid spraying equipment 21 is a 1mmol / L-10mmol / L NaClO2 solution; the absorbing liquid sprayed by the absorbing liquid spraying equipment 31 is an alkaline solution such as NaOH solution, ammonia solution, urea solution and / or NaS2O8 solution.

[0068] This embodiment also provides a method for treating flue gas by oxidative denitration using the above flue gas oxidative denitration device, wherein the method comprises the following steps:

[0069] The flue gas enters the oxidation chamber 2 through the flue gas inlet 11, and uses sodium hypochlorite solution as an oxidant to oxidize nitrogen oxides in the flue gas under the action of a turbulent flow device. The oxidized flue gas enters the absorption chamber 3, and uses an alkaline absorption liquid to remove NOx and other acid gases in the flue gas under the action of a turbulent flow device. The flue gas treated with the absorption liquid enters the demister 4 for demisting treatment, and then enters the NOx concentration detection device 5 through the flue gas outlet 12 for NOx concentration detection. The flue gas whose NOx concentration does not meet the emission standard re-enters the denitrification tower body 1 through the flue gas inlet 11 of the denitrification tower body 1 for secondary flue gas oxidation and denitrification treatment. The flue gas that passes the NOx concentration inspection is discharged, completing the entire oxidation and denitrification treatment process.

[0070] Among them, the sodium hypochlorite solution used for oxidation treatment is recycled through the oxidation liquid circulation system, and the alkaline solution used for absorption treatment is recycled through the oxidation liquid circulation system.

[0071] Comparative Example 1

[0072] This comparative example provides a flue gas oxidation denitrification device (such as Figure 2 As shown), the flue gas oxidation denitrification device is substantially the same as the flue gas oxidation denitrification device provided in Example 1, the only difference being that in this comparative example, no flue gas turbulence equipment is provided in the oxidation chamber and the absorption chamber.

[0073] Specifically, the difference between the oxidation chamber of this comparative example and the oxidation chamber of Example 1 is that no partition and central column are provided; the difference between the absorption chamber of this comparative example and the absorption chamber of Example 1 is that no partition and central column are provided; the rest are the same as Example 1.

[0074] Experimental Example 1

[0075] The flue gas oxidation denitrification devices provided in Example 1 and Comparative Example 1 were used to perform flue gas denitrification, wherein the flue gas to be treated was prepared using cylinder gas, and the NOx concentrations at the flue gas inlet and the flue gas outlet of the flue gas oxidation denitrification devices provided in Example 1 and Comparative Example 1 were monitored and analyzed using a themal 42i-Hl NOx flue gas analyzer; experimental conditions: the flue gas composition was 700 ppm NO, 16 vol% O2, the carrier gas was N2; the flue gas temperature was 80°C; the flue gas volume was 45 m 3 / h; the radius of the oxidation chamber and the absorption chamber is 200mm.

[0076] The experimental results are as follows Figure 3A-3BIt can be seen that the average NO oxidation rate and removal rate of the flue gas oxidation denitrification device with the flue gas turbulence design as shown in Example 1 are higher than the flue gas oxidation denitrification device without the flue gas turbulence design provided in Comparative Example 1, and the flue gas oxidation denitrification device with the flue gas turbulence design as shown in Example 1 has a higher data stability under working conditions, so it can be explained that the flue gas turbulence design as shown in Example 1 has a relatively obvious positive effect in the flue gas oxidation denitrification device.

Claims

1. A flue gas oxidation denitrification device, wherein: The device comprises an oxidation chamber and an absorption chamber connected to the oxidation chamber; the smoke oxidized in the oxidation chamber enters the absorption chamber for absorption; The oxidation chamber is provided with an oxidation liquid spraying device, and the absorption chamber is provided with an absorption liquid spraying device; At least one of the oxidation chamber and the absorption chamber is provided with a flue gas turbulence device; When the oxidation chamber is provided with a flue gas turbulence device, the flue gas turbulence device of the oxidation chamber is used to increase the degree of turbulence of the flue gas entering the oxidation chamber in the oxidation chamber; When the absorption chamber is provided with a smoke turbulence device, the smoke turbulence device of the absorption chamber is used to increase the turbulence degree of the smoke entering the absorption chamber in the absorption chamber; The flue gas turbulence device of the oxidation chamber includes a partition that divides the oxidation chamber into at least two chambers from top to bottom and a central column that runs through the entire oxidation chamber from top to bottom; each chamber of the oxidation chamber is connected to the central column through a grid arranged on the central column, and the central column that runs through the entire oxidation chamber from top to bottom is a hollow structure; each chamber of the oxidation chamber is provided with the oxidation liquid spraying device, and the flue gas inlet of the oxidation chamber is arranged at the bottom chamber; The smoke turbulence device of the absorption chamber includes a partition that divides the absorption chamber into at least two chambers from top to bottom and a central column that runs through the entire absorption chamber from top to bottom; each chamber of the absorption chamber is connected to the central column through a grid arranged on the central column, and the central column that runs through the entire absorption chamber from top to bottom is a hollow structure; each chamber of the absorption chamber is provided with the absorption liquid spraying device, and the smoke inlet of the absorption chamber is arranged at the bottom chamber; The absorption chamber and the oxidation chamber are arranged in the same absorption tower, and the oxidation chamber is located at the lower part of the absorption chamber.

2. The flue gas oxidation denitrification device according to claim 1, wherein: The device is provided with an oxidation liquid circulation system, which includes an oxidation liquid pool arranged in the oxidation chamber and a circulation device connected to the oxidation liquid pool, the oxidation liquid pool is used to collect the oxidation liquid after the flue gas in the oxidation chamber is treated, and the circulation device is used to transport the oxidation liquid collected in the oxidation liquid pool to the oxidation liquid spraying device for recycling; The device is provided with an absorption liquid circulation system, which includes an absorption liquid pool arranged in the absorption chamber and a circulation device connected to the absorption liquid pool. The absorption liquid pool is used to collect the absorption liquid after the flue gas treatment in the absorption chamber, and the circulation device is used to transport the absorption liquid collected in the absorption liquid pool to the absorption liquid spraying device for recycling.

3. The flue gas oxidation denitrification device according to claim 1, wherein: The flue gas oxidation denitration device comprises a denitration tower body, in which an oxidation chamber and an absorption chamber connected to the oxidation chamber are arranged, the oxidation chamber is located at the lower part of the absorption chamber, and the flue gas enters the absorption chamber for absorption after being oxidized by the oxidation chamber, and then is discharged from the denitration tower body through the flue gas outlet; An oxidizing liquid spraying device and a flue gas turbulence device are provided in the oxidation chamber; the flue gas turbulence device of the oxidation chamber comprises a partition that divides the oxidation chamber into two upper and lower chambers and a central column that runs through the entire oxidation chamber from top to bottom; each chamber of the oxidation chamber is connected to the central column through a grille arranged on the central column, and the central column that runs through the entire oxidation chamber from top to bottom is a hollow structure; each chamber of the oxidation chamber is provided with the oxidizing liquid spraying device, and the flue gas inlet of the denitrification tower body is provided in the bottom chamber of the oxidation chamber; An absorption liquid spraying device and a flue gas turbulence device are provided in the absorption chamber. The flue gas turbulence device of the absorption chamber includes a partition that divides the absorption chamber into two upper and lower chambers and a central column that runs through the entire absorption chamber from top to bottom. Each chamber of the absorption chamber is connected to the central column through a grid arranged on the central column. The central column that runs through the entire absorption chamber from top to bottom is a hollow structure. Each chamber of the absorption chamber is provided with the absorption liquid spraying device. The flue gas oxidized in the oxidation chamber enters the absorption chamber from the bottom chamber of the absorption chamber. The denitrification tower body is provided with a dual circulation system, namely an oxidizing liquid circulation system and an absorption liquid circulation system; the oxidizing liquid circulation system comprises an oxidizing liquid pool arranged in the oxidation chamber and a circulation device connected to the oxidizing liquid pool, the oxidizing liquid pool is used to collect the oxidizing liquid after the flue gas in the oxidation chamber is treated, and the circulation device of the oxidizing liquid circulation system is used to transport the oxidizing liquid collected in the oxidizing liquid pool to the oxidizing liquid spraying device for recycling; the absorption liquid circulation system comprises an absorption liquid pool arranged in the absorption chamber and a circulation device connected to the absorption liquid pool, the absorption liquid pool is used to collect the absorption liquid after the flue gas in the absorption chamber is treated, and the circulation device of the absorption liquid circulation system is used to transport the absorption liquid collected in the absorption liquid pool to the absorption liquid spraying device for recycling; wherein, the circulation device of the oxidizing liquid circulation system and / or the circulation device of the absorption liquid circulation system use a circulation pump.

4. The flue gas oxidation denitrification device according to claim 1 or 3, wherein: An oxidation liquid spraying device is provided on the top of the central column of the oxidation chamber; An absorption liquid spraying device is arranged on the top of the central column of the absorption chamber.

5. The flue gas oxidation denitrification device according to claim 1 or 3, wherein: The radius of the oxidation chamber is 3-5 times the radius of the central column of the oxidation chamber; The radius of the absorption cavity is 3-5 times the radius of the central column of the absorption cavity; The opening rate of the grille on the central column of the absorption chamber is 50%-75%; The grid spacing on the central column of the oxidation chamber is 0.05R-0.1R, where R is the radius of the central column; The grid spacing on the central column of the absorption chamber is 0.05R-0.1R, where R is the radius of the central column.

6. The flue gas oxidation denitrification device according to claim 1 or 3, wherein: The radius of the central column of the oxidation chamber is equal to the radius of the central column of the absorption chamber; The radius of the oxidation cavity is equal to the radius of the absorption cavity.

7. The flue gas oxidation denitrification device according to claim 1 or 3, wherein: The oxidizing liquid sprayed by the oxidizing liquid spraying equipment is a NaClO2 solution; The absorption liquid sprayed by the absorption liquid spraying equipment is an alkaline solution.

8. The flue gas oxidation denitrification device according to claim 1 or 3, wherein: The device includes a demister for treating the flue gas treated by the absorption chamber; when the absorption chamber and the oxidation chamber are arranged in the same absorption tower, the demister is arranged between the absorption chamber and the flue gas outlet; The device includes NOx concentration detection equipment and flue gas circulation treatment equipment. The NOx concentration detection equipment is used to detect the NOx concentration in the flue gas after oxidation denitrification treatment, and the flue gas circulation treatment equipment is used to pass the flue gas that fails the NOx concentration check into the oxidation chamber for re-oxidation and denitrification of the flue gas.

9. A method for treating flue gas by oxidative denitration using the flue gas oxidative denitration device according to any one of claims 1 to 8, wherein: The method comprises the steps of using sodium hypochlorite solution as an oxidant to oxidize nitrogen oxides in the flue gas under the action of a turbulent flow device when the flue gas enters an oxidation chamber and / or using an alkaline absorption liquid to remove NOx and other acidic gases in the flue gas after the oxidation by entering an absorption chamber under the action of a turbulent flow device.

10. The method according to claim 9, wherein: The method comprises demisting the flue gas treated with an absorption liquid; The method comprises the following steps: detecting the NOx concentration of the flue gas after the oxidation denitration treatment; the flue gas whose NOx concentration does not meet the emission standard re-enters the oxidation denitration device for secondary oxidation denitration.

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