CN114367180A - Oxidation reaction device and method for flue gas NOx - Google Patents

Abstract

The invention provides an oxidation reaction device and method for flue gas NOx, wherein the oxidation reaction device comprises a reactor shell and at least one group of NOx oxidation reaction units; the NOx oxidation reaction unit comprises a guide plate and a catalytic oxidation unit; the catalytic oxidation unit comprises two groups of reaction pipelines which are oppositely arranged; the reaction pipeline comprises an oxidant conveying pipeline and a catalyst powder conveying pipeline. When the oxidation reaction device provided by the invention is adopted, the movement stroke of the flue gas is increased through the guide plate, and the contact time of the flue gas and the reaction substances is prolonged; the oxidant and the catalyst are conveyed through the oxidant conveying pipeline and the catalyst powder conveying pipeline, the flue gas, the oxidant and the catalyst are fully mixed, and efficient denitration is achieved.

Description

A kind of oxidation reaction device and method for flue gas NOx

technical field

The invention belongs to the technical field of atmospheric treatment, and relates to a flue gas oxidation reaction device, in particular to an oxidation reaction device and method for flue gas NOx.

Background technique

Industrial boilers are important thermal power equipment in power plants. At present, coal is one of the main energy sources, and a large amount of nitrogen oxides (NOx), sulfur dioxide (SO ₂ ) and dust are generated during the combustion of coal in industrial boilers. Among them, NOx and SO ₂ are harmful atmospheric pollutants, which will have a negative impact on the human body, animals, plants and the environment, and dust will cause the PM2.5 index to rise, resulting in a decline in air quality. All parts of my country have specific requirements for the content of nitrogen oxides and sulfur dioxide in the flue gas emitted by power plants. It is necessary to denitrify and desulfurize the flue gas of the boiler and discharge it only after reaching the relevant standards.

At present, the denitrification methods mainly include selective catalytic reduction denitrification (SCR) and selective non-catalytic reduction denitration (SNCR). Among them, the selective catalytic reduction denitrification method has mature technology and high denitration efficiency, and is dominant in practical applications. The use of selective catalytic reduction and denitrification requires the use of SCR catalysts. However, due to alkali metal poisoning, clogging, sintering, wear and other reasons caused by dust in the flue gas, the actual use time of SCR catalysts is often lower than the theoretical operating time, which makes the cost of SCR catalysts become One of the main components of the denitration system of the power plant.

By introducing a denitration pretreatment device, the catalyst load can be reduced, the catalyst service time can be extended, and the nitrogen oxides, sulfur dioxide and dust content in the final exhaust flue gas can be reduced, and the environmental protection indicators of the exhaust flue gas can be improved. Among them, wet combined desulfurization and denitrification has the advantages of stable operation and simple technology, and can be applied to denitrification pretreatment devices. Since about 95% of NOx in flue gas is NO with low solubility, it is difficult to directly absorb and remove it. It is necessary to fully mix flue gas, oxidant and catalyst in the NOx oxidation reactor to oxidize NO to higher solubility. of NO ₂ and N ₂ O ₅ .

CN 105749748A discloses an integrated desulfurization and denitrification device, comprising a top silo, a shell, an ammonia injection main pipe, a denitration chamber, an air inlet, an exhaust port, a discharge valve, a bracket, and the shell is divided into upper and lower annular partitions The upper denitrification zone, the middle buffer zone and the lower desulfurization zone are divided into three parts. The denitration zone and the sulphur zone are divided into different chambers by the inverted truncated hollow cone and the truncated hollow cone. The denitration zone is clean flue gas from outside to inside. Outlet chamber, denitrification chamber and denitrification inlet chamber; the desulfurization inlet chamber, desulfurization chamber and denitration outlet chamber are sequentially formed from the outside to the inside of the bowl removal area: the desulfurization chamber and the denitration chamber are connected through the feeding pipe of the buffer zone , the desulfurization gas outlet chamber and the denitration gas inlet chamber are communicated through the vortex mixed ammonia chamber of the buffer zone. Although the activated carbon purification technology has the effect of removing various pollutants, especially the removal of sulfur dioxide, it is difficult to achieve a high denitrification rate, and the flue gas purification has to be carried out at low air velocity. In the activated coke process, the space velocity is usually around 300-500h ^-1 , which makes the overall equipment huge, the equipment investment and operating costs are high, the activated carbon consumption is large, the material consumption cost is high, and the denitration rate is difficult to meet the requirements.

CN107511064A discloses a desulfurization and denitrification device based on activated carbon and low-temperature catalyst, which includes a bag filter, a smoke chamber, a fluidization chamber and a cyclone that are connected in sequence, wherein a conical ash hopper is arranged at the bottom of the smoke chamber and is connected to an ammonia water source and a cyclone. High-speed airflow source. By using activated carbon as the carrier of the low-temperature catalyst, the activated carbon is in a fluidized state, so that the flue gas is fully contacted with the low-temperature catalyst and the activated carbon, and desulfurization and denitrification can be achieved in one step, and the activated carbon and the activated carbon as the carrier of the low-temperature catalyst do not need to be separated later. , which can be reprocessed as a carrier for low-temperature catalysts. However, the desulfurization and denitrification efficiency of the desulfurization and denitrification device is not high enough.

CN 203803374U discloses a wet catalytic oxidation denitration device, the device comprises a catalytic oxidation reaction furnace, a flue gas supply system for sending the treated flue gas into the catalytic oxidation reaction furnace, an oxidant supply system and a reaction product collection system; catalytic oxidation A carrying plate for placing the catalyst carrier is installed in the reaction furnace, and a catalyst carrier replacement door is opened on its side wall; the oxidant supply system includes an oxidant delivery pipe for feeding liquid oxidant into the catalytic oxidation reaction furnace and spraying the liquid oxidant To the spray device on the catalyst carrier, a booster pump is arranged on the oxidant conveying pipe; the flue gas supply system includes a flue gas conveying pipe; the flue gas conveying pipe is equipped with pressurizing equipment and heating equipment; the reaction product collection system includes a collection bottle and a There is a reaction product discharge pipe with a cooling device. In the wet catalytic oxidation denitration process, the mixing of flue gas, oxidant and catalyst is insufficient, resulting in a low NO oxidation rate, which is the main reason for the low denitration efficiency of the wet absorption process.

To sum up, it is one of the urgent problems to be solved in the art to provide a denitration reactor for the purpose of improving the oxidation rate of NO and improving the denitration efficiency by improving the mixing degree of flue gas, oxidant and catalyst.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide an oxidation reaction device and method for flue gas NOx. When the oxidation reaction device is used, the flue gas movement stroke is increased through the deflector, and the contact time between the flue gas and the reaction material is increased; the oxidant and the catalyst are transported through the oxidant transportation pipeline and the catalyst powder transportation pipeline, and the flue gas, the oxidant and the catalyst are fully mixed. , to achieve efficient denitrification.

In order to achieve this object of the invention, the present invention adopts the following technical solutions:

In a first aspect, the present invention provides an oxidation reaction device for flue gas NOx, the oxidation reaction device comprising a reactor shell and at least one group of NOx oxidation reaction units;

The NOx oxidation reaction unit includes a guide plate and a catalytic oxidation unit;

The catalytic oxidation unit includes two sets of reaction pipes arranged oppositely;

The reaction pipeline includes an oxidant delivery pipeline and a catalyst powder delivery pipeline.

The invention increases the flue gas movement stroke through the NOx oxidation reaction unit, increases the contact time between the flue gas and the reactant, and realizes the full mixing of the flue gas, the oxidant and the catalyst, thereby improving the denitration efficiency.

Preferably, the deflector includes a first deflector and a second deflector.

Preferably, the first air guide plate includes a first fixing plate, a first air guide plate and a second air guide plate.

Preferably, the second air guide plate includes a second fixed plate, a third air guide plate and a fourth air guide plate.

Preferably, the first fixing plate and the second fixing plate are respectively and independently fixed on the side wall of the reactor shell.

The first guide plate and the second guide plate of the present invention are arranged alternately, and the two together form a NOx oxidation reaction unit, which controls the flow direction of the flue gas, thereby increasing the movement stroke of the flue gas and the contact time with the reactant. , to achieve efficient denitrification of flue gas.

If there are two or more groups of NOx oxidation reaction units in the oxidation reaction device for flue gas NOx according to the present invention, the fixed plate in the former group of the adjacent two groups of NOx oxidation reaction units is regarded as the middle plate in the latter group. the fixing plate is used. The above structural scheme can not only save the internal space of the device, but also control the flow path of the flue gas.

Preferably, the angle between the first fixing plate and the side wall of the reactor shell is 50-90°, such as 50°, 55°, 60°, 65°, 70°, 75°, 80°, 85° Or 90°, but not limited to the recited values, other unrecited values within the numerical range are also applicable.

Preferably, the angle between the second fixing plate and the side wall of the reactor shell is 50-90°, such as 50°, 55°, 60°, 65°, 70°, 75°, 80°, 85° Or 90°, but not limited to the recited values, other unrecited values within the numerical range are also applicable.

The angle between the fixing plate and the side wall of the reactor shell in the present invention specifically refers to the angle formed by the fixing plate and the side wall of the reactor shell after the fixing plate is inclined downward.

Preferably, the first air guide plate is perpendicular to the ground at the end of the first fixing plate away from the side wall.

Preferably, the third air guide plate is perpendicular to the ground and is disposed at the end point of the second fixing plate away from the side wall.

Preferably, the second guide plate is arranged between the first guide plate and the third guide plate perpendicular to the ground.

Preferably, the fourth air guide plate is arranged between the first air guide plate and the second air guide plate perpendicular to the ground.

The first and second flow guide plates of the present invention are fixedly arranged above the first fixing plate, and the third and fourth flow guide plates are fixedly arranged below the second fixing plate. The first drainage plate, the second drainage plate, the third drainage plate and the fourth drainage plate are crossed in the same space to form a flue gas circulation route, thereby controlling the flue gas circulation route.

Preferably, the distance between the two groups of reaction tubes is 20-60cm, such as 20cm, 25cm, 30cm, 35cm, 40cm, 45cm, 50cm, 55cm or 60cm, but not limited to the listed values, other values within the range of values The same applies to non-recited values.

Preferably, the reaction pipeline is arranged between the first flow guide plate and the side wall of the reactor shell parallel to the ground.

Preferably, an oxidant atomizing nozzle is provided on the oxidant delivery pipeline.

Preferably, the catalyst powder conveying pipeline is provided with a catalyst powder nozzle.

Preferably, the number of oxidant atomizing nozzles and catalyst powder nozzles is the same.

Preferably, the oxidant conveying pipeline and the catalyst powder conveying pipeline are alternately arranged parallel to the reaction plate.

The NOx oxidation reaction unit provided by the present invention is provided with two groups of reaction tubes, which are arranged opposite to each other, and the catalyst powder nozzles and the oxidant atomizing nozzles arranged on the reaction tubes are arranged opposite to each other; The oxidant atomizing nozzles are arranged in a staggered manner, so that the catalyst and the oxidant can pass through the completely opposite speed directions and spray the catalyst powder and the oxidant at the same time, so as to achieve the purpose of fully mixing the catalyst and the oxidant, and improve the denitration efficiency.

Preferably, the distances between the first, second, third, fourth, and fourth flow guide plates and the side wall of the reactor shell satisfy the following formula:

D1≥D2≥D3≥D4

In the formula, D1 is the spacing between the first guide plate and the side wall of the reactor shell; D2 is the spacing between the first guide plate and the fourth guide plate; D3 is the fourth guide plate and the spacing between the second guide plate; D4 is the distance between the second flow guide plate and the third flow guide plate.

Preferably, the distances between the first, second, third, and fourth drain plates and the first fixed plate and the second fixed plate satisfy the following formulas:

L1≥L2≥L3≥L4

In the formula, L1 is the distance between the first drainage plate and the second fixed plate, L2 is the distance between the fourth drainage plate and the first fixed plate, L3 is the distance between the second drainage plate and the second fixed plate, and L4 is the distance between the second drainage plate and the second fixed plate. The distance between the third flow guide plate and the first fixed plate.

According to the present invention, the distance between each guide plate and the side wall, and the distance between the guide plate and the fixed plate are different, so that the flue gas starts from the catalytic oxidation unit, and when the flue gas flows through the guide plate, the cross section changes from large to small, and The frequency of flue gas velocity change increases continuously until the next catalytic oxidation unit position. The mixing effect is enhanced by the change of speed size and frequency of speed change, and the denitration efficiency is improved.

In a second aspect, the present invention provides a method using the oxidation reaction device for flue gas NOx provided in the first aspect, the method comprising the following steps:

After the flue gas containing NOx is pretreated, it is passed into the inside of the oxidation reaction device for flue gas NOx, and the purified flue gas is obtained after the oxidation treatment and the catalytic treatment are carried out at least once.

Preferably, the pretreatment includes preheating and electrostatic precipitating performed in sequence;

Preferably, the temperature of the preheated flue gas is 120-160°C, such as 120°C, 125°C, 130°C, 135°C, 140°C, 145°C, 150°C, 155°C or 160°C, but not Limitations to the recited values apply equally to other non-recited values within the numerical range.

Preferably, the flow rate of the flue gas is 5-8m/s, for example, it can be 5m/s, 6m/s, 7m/s or 8m/s, but is not limited to the listed values, and other unlisted values within the value range The same applies to numerical values.

Preferably, the catalyst powder used in the catalytic treatment process includes any one or a combination of at least two of Fe ₂ O ₃ , MnO, TiO ₂ or CuO, and a typical but non-limiting combination includes Fe ₂ O ₃ and MnO combination of MnO and _TiO2 , combination of _TiO2 and _CuO , combination of _Fe2O3 , MnO and _TiO2 , combination of MnO, _TiO2 and _CuO , or combination of _Fe2O3 , MnO, _TiO2 and CuO The combination.

Preferably, the average particle size of the catalyst powder is 60-80 μm, such as 60 μm, 62 μm, 64 μm, 66 μm, 68 μm, 70 μm, 72 μm, 74 μm, 76 μm, 78 μm or 80 μm, but not limited to the listed numerical values, numerical values The same applies to other non-recited values in the range.

Preferably, the spraying speed of the catalyst powder is 10-15m/s, such as 10m/s, 11m/s, 12m/s, 13m/s, 14m/s or 15m/s, but not limited to those listed Numerical values, other non-recited values within the numerical range also apply.

Preferably, the oxidant liquid used in the oxidation treatment process includes any one or a combination of at least two of H ₂ O ₂ , KMnO ₄ , NaClO or NaClO ₂ , and a typical but non-limiting combination includes H ₂ O ₂ , KMnO ₄ combination, H ₂ O ₂ , KMnO ₄ and NaClO combination, KMnO ₄ and NaClO combination, NaClO and NaClO ₂ combination, H ₂ O ₂ , and NaClO ₂ combination, H ₂ O ₂ , KMnO ₄ and NaClO ₂ , or a combination of H ₂ O ₂ , KMnO ₄ , NaClO and NaClO ₂ .

The oxidant liquid of the present invention atomizes the oxidant into mist droplets with a volume median diameter of 80-100 μm through the spray of the oxidant atomizing nozzle.

Since the particle sizes of the catalyst powder and the oxidant droplets are similar and the particle size of the oxidant droplets is slightly larger than that of the catalyst powder, the oxidant droplets can better coat the surface of the catalyst powder during the spraying process, and have a larger contact ratio. The surface area is conducive to promoting the redox reaction.

Preferably, the flow rate of the oxidant liquid is 10-15m/s, such as 10m/s, 11m/s, 12m/s, 13m/s, 14m/s or 15m/s, but not limited to the listed values , other non-recited values within the numerical range also apply.

The invention realizes the optimization of the mixing uniformity among the oxidant, the catalyst powder and the flue gas by controlling the flow rates of the oxidant, the catalyst powder and the flue gas, and achieves the purpose of improving the denitration efficiency by improving the NO oxidation efficiency.

As a preferred technical solution of the present invention, the second aspect of the present invention provides a method using the oxidation reaction device for flue gas NOx provided in the first aspect, the method comprising the following steps:

The flue gas containing NOx is preheated to 120-160°C, and after electrostatic precipitating, it is passed into the interior of the oxidation reaction device for flue gas NOx at a flow rate of 5-8m/s, and the oxidation treatment and catalytic treatment are carried out at least once. Then the purified flue gas is obtained; the average particle size of the catalyst powder used in the catalytic process is 60-80 μm; the injection speed is 10-15 m/s; the flow rate of the oxidant in the oxidation process is 10-15 m/s.

The numerical range described in the present invention not only includes the above-mentioned exemplified point values, but also includes any point value between the above-mentioned numerical ranges that are not exemplified. Due to space limitations and for the sake of brevity, the present invention will not exhaustively list them. The specific point value included in the above range.

Compared with the prior art, the present invention has the following beneficial effects:

(1) The oxidation reaction device for flue gas NOx provided by the present invention is simple in structure, and can improve the mixing uniformity of solid catalyst powder, liquid oxidant and gaseous flue gas, improve NO oxidation efficiency, and thereby improve denitration efficiency;

(2) The oxidation reaction device for flue gas NOx provided by the present invention can prolong the service life of the catalyst and reduce the average annual input cost of the denitration catalyst;

(3) The catalytic oxidation denitration process is carried out by using the oxidation reaction device for flue gas NOx provided by the present invention, which has good economic and environmental benefits.

Description of drawings

1 is a schematic structural diagram of an oxidation reaction device for flue gas NOx provided by Embodiment 1 of the present invention;

Fig. 2 is the front view of the reaction pipeline provided by the embodiment of the present invention 1;

FIG. 3 is a schematic view of the dimensions provided by Embodiment 1 of the present invention.

Among them, 1 is the reactor shell, 2-1 is the oxidant transportation pipeline, 2-2 is the catalyst powder transportation pipeline, 2-3 is the oxidant atomizing nozzle, 2-4 is the catalyst powder nozzle, and 3-1 is the first Fixing plates, 3-2 is the first drainage plate, 3-3 is the second drainage plate, 4-1 is the second fixing plate, 4-2 is the third drainage plate, and 4-3 is the fourth drainage plate.

Detailed ways

The technical solutions of the present invention are further described below through specific embodiments. It should be understood by those skilled in the art that the embodiments are only for helping the understanding of the present invention, and should not be regarded as a specific limitation of the present invention.

Example 1

This embodiment provides an oxidation reaction device for flue gas NOx as shown in FIG. 1 , the reaction device includes a reactor shell 1 and four groups of NOx oxidation reaction units;

The NOx oxidation reaction unit includes a guide plate and a catalytic oxidation unit; the catalytic oxidation unit includes two sets of reaction pipes 2 arranged oppositely; the reaction pipes include an oxidant conveying pipe 2-1 and a catalyst powder conveying pipe 2-2 .

The deflector includes a first deflector and a second deflector; the first deflector includes a first fixing plate 3-1, a first deflector 3-2 and a second deflector 3-3; The second air guide plate includes a second fixed plate 4-1, a third air guide plate 4-2 and a fourth air guide plate 4-3; the first fixed plate 3-1 and the second fixed plate 4-1 are respectively It is independently fixed on the side wall of the reactor shell 1 .

The included angle between the first fixing plate 3-1 and the side wall of the reactor shell 1 is 75°; the included angle between the second fixing plate 4-1 and the side wall of the reactor shell 1 is 75°.

The first guide plate 3-2 is arranged perpendicular to the ground at the end point of the first fixed plate 3-1 away from the side wall of the reactor shell 1; the third guide plate 4-2 is arranged perpendicular to the ground on the second fixed plate 4-1 is far away from the end point of the side wall of the reactor shell 1; the second guide plate 3-3 is perpendicular to the ground and is arranged between the first guide plate 3-2 and the third guide plate 4-2; the fourth The drainage plate 4-3 is perpendicular to the ground and is arranged between the first drainage plate 3-2 and the second drainage plate 3-3.

The spacing between the two groups of reaction pipes is 40cm;

The reaction pipeline is arranged between the first guide plate 3-2 and the side wall of the reactor shell 1 parallel to the ground; as shown in Figure 2, the oxidant transport pipeline 2-1 is provided with an oxidant atomizing nozzle 2-3 ; The catalyst powder delivery pipeline 2-2 is provided with catalyst powder nozzles 2-4; the oxidant atomizing nozzles 2-3 have the same number as the catalyst powder nozzles 2-4; the oxidant delivery pipeline 2-1 and the catalyst The powder conveying pipes 2-2 are arranged alternately in parallel.

The distances between the first flow guide plate 3-2, the second flow guide plate 3-3, the third flow guide plate 4-2, the fourth flow guide plate 4-3 and the side wall of the reactor shell 1 satisfy the following formula:

D1≥D2≥D3≥D4

As shown in Figure 3, in the formula, D1 is the distance between the first guide plate 3-2 and the side wall of the reactor shell 1; D2 is the distance between the first guide plate 3-2 and the fourth guide plate 4-3; D3 is the distance between the fourth drainage plate 4-3 and the second drainage plate 3-3; D4 is the distance between the second drainage plate 3-3 and the third drainage plate 4-2.

Moreover, the relationship among D1, D2, D3 and D4 in this embodiment is: D1/D2=D2/D3=D3/D4=1.5.

Between the first drainage plate 3-2, the second drainage plate 3-3, the third drainage plate 4-2, the fourth drainage plate 4-3 and the first fixing plate 3-1 and the second fixing plate 4-1 Each spacing satisfies the following formula:

L1≥L2≥L3≥L4

As shown in Figure 3, in the formula, L1 is the distance 4-1 between the first flow guide plate 3-2 and the second fixed plate, and L2 is the distance 3-1 between the fourth flow guide plate 4-3 and the first fixed plate , L3 is the distance between the second flow guide plate 3-3 and the second fixed plate 4-1, and L4 is the distance between the third flow guide plate 4-2 and the first fixed plate 3-1.

Moreover, in this embodiment, the relationship among L1, L2, L3 and L4 is: L1/L2=L2/L3=L3/L4=1.5.

Example 2

This embodiment provides an oxidation reaction device for flue gas NOx, and the difference between the reaction device and Embodiment 1 is only that a group of NOx oxidation reaction units are provided in this embodiment.

Example 3

This embodiment provides an oxidation reaction device for NOx. The difference between the reaction device and the embodiment 1 is only: the angle between the first fixing plate 3-1 in this embodiment and the side wall of the reactor shell 1 is 90°; the included angle between the second fixing plate 4-1 and the side wall of the reactor shell 1 is 90°.

Example 4

This embodiment provides an oxidation reaction device for NOx. The difference between the reaction device and the embodiment 1 is only: the angle between the first fixing plate 3-1 in this embodiment and the side wall of the reactor shell 1 is 60°; the included angle between the second fixing plate 4-1 and the side wall of the reactor shell 1 is 60°.

Example 5

This embodiment provides an oxidation reaction device for NOx. The difference between the reaction device and the embodiment 1 is only: the angle between the first fixing plate 3-1 in this embodiment and the side wall of the reactor shell 1 is 30°; the included angle between the second fixing plate 4-1 and the side wall of the reactor shell 1 is 30°.

Example 6

This embodiment provides an oxidation reaction device for NOx. The difference between the reaction device and the embodiment 1 is that the relationship among D1, D2, D3 and D4 is changed to: D1/D2=D2/D3= D3/D4=1.2; the relationship among L1, L2, L3 and L4 is changed to: L1/L2=L2/L3=L3/L4=1.2.

Example 7

This embodiment provides an oxidation reaction device for NOx. The difference between the reaction device and the embodiment 1 is that the relationship among D1, D2, D3 and D4 is changed to: D1/D2=D2/D3= D3/D4=0.9; the relationship among L1, L2, L3 and L4 is changed to: L1/L2=L2/L3=L3/L4=0.9.

Application example 1

This application example provides a method using the NOx oxidation reaction device provided in Example 1, and the method includes the following steps:

The flue gas containing NOx is preheated to 140 ℃, and after electrostatic precipitating, it is passed into the interior of the oxidation reaction device for flue gas NOx at a flow rate of 6m/s, and the oxidation treatment and catalytic treatment are carried out at least once, and then purified. The average particle size of the catalyst powder Fe ₂ O ₃ used in the catalytic process is 70 μm; the injection speed is 12 m/s; the flow rate of the oxidant H ₂ O ₂ in the oxidation process is 12 m/s.

Application example 2

This application example provides a method using the oxidation reaction device for NOx provided in Example 2, and the method is the same as that of Application Example 1.

Application example 3

This application example provides a method using the NOx oxidation reaction device provided in Example 3, and the method is the same as that of Application Example 1.

Application example 4

This application example provides a method using the oxidation reaction device for NOx provided in Example 4, and the method is the same as that of Application Example 1.

Application example 5

This application example provides a method using the NOx oxidation reaction device provided in Example 5, and the method is the same as that of Application Example 1.

Application example 6

This application example provides a method using the NOx oxidation reaction device provided in Example 6, and the method is the same as that of Application Example 1.

Application example 7

This application example provides a method using the oxidation reaction device for NOx provided in Example 7, and the method is the same as that of Application Example 1.

Application example 8

This application example provides a method using the NOx oxidation reaction device provided in Example 1, and the method includes the following steps:

The flue gas containing NOx is preheated to 120°C, and after electrostatic precipitating, it is passed into the inside of the oxidation reaction device for flue gas NOx at a flow rate of 5m/s, and the oxidation treatment and catalytic treatment are carried out at least once to obtain purification. The average particle size of the catalyst powder TiO ₂ used in the catalytic process is 60 μm; the injection speed is 10 m/s; the flow rate of the oxidant KMnO ₄ in the oxidation process is 10 m/s.

Application example 9

This application example provides a method using the NOx oxidation reaction device provided in Example 1, and the method includes the following steps:

The flue gas containing NOx is preheated to 160°C, and after electrostatic precipitating, it is passed into the interior of the oxidation reaction device for flue gas NOx at a flow rate of 8 m/s, and the oxidation treatment and catalytic treatment are carried out at least once to obtain purification. The average particle size of the catalyst powder CuO used in the catalytic process is 80 μm; the injection speed is 15 m/s; the flow rate of the oxidant NaClO in the oxidation process is 15 m/s.

Application example 10

This application example provides a method using the NOx oxidation reaction device provided in Example 1. The difference between the method and Application Example 1 is that the preheating temperature of flue gas containing NOx is changed to 100°C.

Application example 11

This application example provides a method using the NOx oxidation reaction device provided in Example 1. The difference between the method and Application Example 1 is that the preheating temperature of flue gas containing NOx is changed to 200°C.

Application example 12

This application example provides a method using the NOx oxidation reaction device provided in Example 1. The difference between the method and Application Example 1 is that the flow rate of flue gas containing NOx is changed to 10 m/s.

The flue gas containing NOx and the treated flue gas provided in application examples 1-12 were passed into the flue gas analyzer to measure the concentration change of NOx in the flue gas before and after the reaction, and the removal efficiency was calculated. The results are shown in Table 1.

Table 1

To sum up, when the oxidation reaction device provided by the present invention is adopted, the flue gas movement stroke is increased through the deflector, and the contact time between the flue gas and the reaction substance is increased; Mixing flue gas, oxidant and catalyst to achieve efficient denitrification.

The applicant declares that the above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should Changes or substitutions that can be easily conceived within the technical scope all fall within the protection scope and disclosure scope of the present invention.

Claims (10)

1. The oxidation reaction device for the NOx in the flue gas is characterized by comprising a reactor shell and at least one group of NOx oxidation reaction units;

the NOx oxidation reaction unit comprises a guide plate and a catalytic oxidation unit;

the catalytic oxidation unit comprises two groups of reaction pipelines which are oppositely arranged;

the reaction pipeline comprises an oxidant conveying pipeline and a catalyst powder conveying pipeline.

2. The oxidation reaction device for flue gas NOx of claim 1 wherein the baffle comprises a first baffle and a second baffle;

preferably, the first flow guide plate comprises a first fixing plate, a first flow guide plate and a second flow guide plate;

preferably, the second flow guide plate comprises a second fixing plate, a third flow guide plate and a fourth flow guide plate;

preferably, the first fixing plate and the second fixing plate are respectively and independently fixedly arranged on the side wall of the reactor shell.

3. The oxidation reaction device for flue gas NOx as claimed in claim 2, wherein the first retaining plate is angled from the side wall of the reactor housing by 50-90 °;

preferably, the included angle between the second fixing plate and the side wall of the reactor shell is 50-90 degrees;

preferably, the first flow guide plate is arranged at the end point, far away from the side wall of the reactor shell, of the first fixing plate, and is vertical to the ground;

preferably, the third flow guide plate is arranged at the end point, far away from the side wall of the reactor shell, of the second fixing plate, and is vertical to the ground;

preferably, the second drainage plate is arranged between the first drainage plate and the third drainage plate perpendicular to the ground;

preferably, the fourth flow-guiding plate is disposed between the first and second flow-guiding plates perpendicular to the ground.

4. The oxidation reaction device for flue gas NOx of any one of claims 1 to 3, wherein a distance between the two sets of reaction tubes is 20-60 cm;

preferably, the reaction pipe is arranged between the first flow guide plate and the side wall of the reactor shell in parallel with the ground;

preferably, the oxidant delivery pipeline is provided with an oxidant atomizing nozzle;

preferably, the catalyst powder conveying pipeline is provided with a catalyst powder nozzle;

preferably, the number of the oxidant atomizer nozzles and the number of the catalyst powder nozzles are the same;

preferably, the oxidant delivery pipes and the catalyst powder delivery pipes are alternately arranged in parallel.

5. The oxidation reaction device for flue gas NOx of any one of claims 2 to 4, wherein the respective distances between the first flow guide plate, the second flow guide plate, the third flow guide plate, the fourth flow guide plate and the side wall of the reactor shell satisfy the following formula:

D1≥D2≥D3≥D4

wherein D1 is the distance between the first flow guide plate and the side wall of the reactor shell; d2 is the distance between the first drainage plate and the fourth drainage plate; d3 is the distance between the fourth drainage plate and the second drainage plate; d4 is the distance between the second drainage plate and the third drainage plate.

6. The oxidation reaction device for flue gas NOx of any one of claims 2 to 5, wherein the respective distances between the first flow guide plate, the second flow guide plate, the third flow guide plate and the fourth flow guide plate and the first fixing plate and the second fixing plate satisfy the following formulas:

L1≥L2≥L3≥L4

in the formula, L1 is the distance between the first drainage plate and the second fixing plate, L2 is the distance between the fourth drainage plate and the first fixing plate, L3 is the distance between the second drainage plate and the second fixing plate, and L4 is the distance between the third drainage plate and the first fixing plate.

7. A method carried out with the oxidation reaction device for flue gases NOx of any one of claims 1 to 6, characterized in that it comprises the following steps:

and after the flue gas containing NOx is pretreated, introducing the flue gas into the oxidation reaction device for the NOx in the flue gas, and simultaneously carrying out oxidation treatment and catalytic treatment for at least one time to obtain the purified flue gas.

8. The method of claim 7, wherein the pre-treatment comprises preheating and electrostatic precipitation in sequence;

preferably, the temperature of the preheated flue gas is 120-160 ℃;

preferably, the flow velocity of the flue gas is 5-8 m/s.

9. A method according to claim 7 or 8, wherein the catalytic powder used in the catalytic treatment comprises Fe₂O₃、MnO、TiO₂Or CuO, or a combination of at least two thereof;

preferably, the catalyst powder has an average particle diameter of 60 to 80 μm;

preferably, the spraying speed of the catalyst powder is 10 to 15 m/s.

10. A method according to any one of claims 7 to 9, wherein the oxidising treatment is carried out using an oxidising liquid comprising H₂O₂、KMnO₄NaClO or NaClO₂Any one or a combination of at least two of;

preferably, the flow rate of the oxidant liquid is 10-15 m/s.

Images