CN217247940U

CN217247940U - Low-temperature wet flue gas denitration device

Info

Publication number: CN217247940U
Application number: CN202122753400.8U
Authority: CN
Inventors: 杨大颖; 周坤明; 熊伟; 陈傲
Original assignee: Hubei Lusheng Environmental Engineering Co ltd
Current assignee: Hubei Lusheng Environmental Engineering Co ltd
Priority date: 2021-11-11
Filing date: 2021-11-11
Publication date: 2022-08-23
Anticipated expiration: 2031-11-11

Abstract

The utility model relates to a flue gas denitration technical field discloses a low temperature wet flue gas denitration device, including denitration reduction tower, by supreme circulation groove, spray set, defroster and the gas outlet of being provided with down in the denitration reduction tower, the circulation groove passes through backwash pump and back flow and links to each other with the defogging subassembly, and the circulation groove links to each other with the urea storage tank through adding the pencil, is connected with the intake pipe on the denitration reduction tower, and the end of giving vent to anger of intake pipe is located the spray set below, and the inlet end of intake pipe links to each other with NOx oxidation assembly. The utility model has the advantages of it is following and effect: the raw material adopted in the low-temperature wet flue gas denitration process is urea (containing organic auxiliary agent), and the reaction products are carbon dioxide, nitrogen and water. The waste liquid after denitration is recycled after urea is supplemented, waste water body with secondary pollution is not generated, and the problems of acid pollution, more side reactions, difficult treatment of byproducts and the like in the traditional washing method, alkali absorption method and other processes are solved.

Description

Low-temperature wet flue gas denitration device

Technical Field

The utility model relates to a flue gas denitration technology field, in particular to low temperature wet flue gas denitration device.

Background

At present, the related flue gas denitration technology is mainly a Selective Catalytic Reduction (SCR) flue gas denitration technology.

The Selective Catalytic Reduction (SCR) denitration technology has high efficiency and mature denitration technology. The technology mainly takes NH3 as a reducing agent, and NH3 selectively reduces NO and NO2 in exhaust gas into nitrogen and water vapor under the action of a certain temperature and a catalyst. In the SCR process, there are high, medium and low temperature SCR catalysts according to the catalytic reaction temperature of the catalyst used.

In the operation of the SCR denitration device, except for the reducing agent NH ₃ In addition to being a consumable in an operating process, the useful life of the catalyst is an important factor. The lifetime of the catalyst depends on the decay rate of the catalyst activity. After the catalyst is operated for a period of time, the surface activity of the catalyst is reduced, and physical deactivation and chemical deactivation exist. The physical inactivation of the catalyst mainly refers to the activity damage of the catalyst caused by high-temperature sintering, abrasion and solid particle deposition and blockage; the chemical deactivation of the catalyst is mainly the catalyst poisoning caused by alkali metals and heavy metals. In practical application, the slag fly ash generated by fuel combustion can also cause the blockage of catalyst micropores. Because the content of calcium oxide in the ash after combustion is very high, calcium sulfate generated by the calcium oxide is adsorbed on the surface of the catalyst, and the reactants are prevented from diffusing to the surface of the catalyst and diffusing into the catalyst, so that the activity of the catalyst is reduced.

Generally, the catalyst used in the SCR process needs to be replaced about 2 to 3 years, because the catalyst itself is used in a large amount and is expensive, the use cost of the catalyst is very high. In addition, continuous supplement of ammonia gas is needed in the SCR process, and the problem of ammonia gas escape exists. Therefore, considering the problems of ammonia gas supplement and catalyst replacement, the SCR denitration device has large one-time investment and high overall operation cost, and the improper operation can generate secondary pollution caused by escaping ammonia gas.

SUMMERY OF THE UTILITY MODEL

The utility model aims at providing a low temperature wet flue gas denitration device has and need not to adopt the catalyst, no secondary pollution, effect that the working costs is low.

The above technical object of the present invention can be achieved by the following technical solutions: including denitration reduction tower, denitration reduction tower is interior by supreme circulation groove, spray assembly, defroster and the gas outlet of being provided with down, the circulation groove passes through backwash pump and back flow and links to each other with the defogging subassembly, the circulation groove links to each other with the urea storage tank through adding the pencil, be connected with the intake pipe on the denitration reduction tower, the end of giving vent to anger of intake pipe is located spray assembly below, the inlet end and the NOx oxidation subassembly of intake pipe link to each other.

The utility model discloses a further set up to: the spraying assembly comprises a plurality of layers of spraying pipes, the spraying pipes are connected with the return pipe, and spraying heads are uniformly arranged on the spraying pipes.

The utility model discloses a further set up to: the NOx oxidation assembly comprises an oxidation reaction chamber, the two ends of the oxidation reaction chamber are respectively and rotatably connected with a NOx inlet head and an ozone inlet head, one end of the NOx inlet head, far away from the oxidation reaction chamber, is rotatably connected with a NOx inlet pipe, one end of the ozone inlet head, far away from the oxidation reaction chamber, is rotatably connected with an ozone inlet pipe, a driving assembly for driving the NOx inlet head and the ozone inlet head to rotate is arranged on the oxidation reaction chamber, and the side wall of the oxidation reaction chamber is connected with an inlet pipe.

The utility model discloses a further set up to: the drive assembly comprises a first gear ring fixedly connected to the NOx inlet head and a second gear ring fixedly connected to the ozone inlet head, a motor is arranged on the oxidation reaction chamber, a driving bevel gear is fixedly connected to the output end of the motor, two driven bevel gears are symmetrically arranged on two sides of the driving bevel gear and meshed with the driving bevel gear, a rotating shaft is fixedly connected to the driven bevel gears, one end of the rotating shaft, far away from the driven bevel gears, is fixedly connected with a drive gear, and the two drive gears are meshed with the first gear ring and the second gear ring respectively.

The utility model discloses a further set up to: the first gear ring, the second gear ring and the driving gear are all helical gears.

The utility model discloses a further set up to: and the NOx air inlet head and the ozone air inlet head are connected with the oxidation reaction chamber through a rotary joint.

The utility model discloses a further set up to: one end of the ozone inlet pipe, which is far away from the oxidation reaction chamber, is connected with an ozone generator.

The utility model has the advantages that:

1. the raw material adopted in the low-temperature wet flue gas denitration process is urea (containing organic auxiliary agent), and the reaction products are carbon dioxide, nitrogen and water. The waste liquid after denitration is recycled after urea is supplemented, waste water body with secondary pollution is not generated, and the problems of acid pollution, more side reactions, difficult treatment of byproducts and the like in the traditional washing method, alkali absorption method and other processes are solved.

2. In a urea wet flue gas denitration reaction system, urea in a solution can directly react with NOx dissolved in a liquid phase, and the NOx is transferred from a gas state to a water phase mainly through the absorption balance of the NOx in the solution. The main obstacle of liquid phase removal of NOx (generally, NO accounts for more than 90%) in flue gas is that NO has very low solubility in water, so that the key point of the urea wet denitration technology is to convert NO into a form easy to absorb. The present application employs ozone to oxidize NO to NO ₂ And the gas can be fully oxidized before being absorbed, so that the flue gas denitration reaction efficiency of the urea wet method is improved.

And 3, NOx and ozone enter the oxidation reaction chamber through the NOx inlet head and the ozone inlet head respectively, the rotation directions of the NOx inlet head and the ozone inlet head are opposite under the action of the driving assembly, and two opposite high-speed airflows collide in the oxidation reaction chamber, so that the ozone and the NOx are fully mixed and contacted, the NOx is fully oxidized, and the NOx treatment efficiency is improved.

4. The NOx air inlet head and the ozone air inlet head are driven to rotate by the driving bevel gear and the two symmetrical driven bevel gears, the NOx air inlet head and the ozone air inlet head can be driven to rotate in opposite directions by the motor, the bevel gear is high in transmission precision, the NOx air inlet head and the ozone air inlet head can be guaranteed to rotate at high speed, and the air flow mixing effect is improved.

5. The first gear ring, the second gear ring and the driving gear are all set to be helical gears, the helical gears are stable in transmission, impact, vibration and noise are small, and the driving gear is suitable for driving the NOx air inlet head and the ozone air inlet head to rotate at a high speed.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

Fig. 1 is a schematic structural view of the present invention.

FIG. 2 is a schematic view of the connection of the NOx oxidizing assembly and the drive assembly.

FIG. 3 is a schematic illustration of the positional relationship of the NOx oxidizing assembly and the drive assembly.

In the figure, 1, a denitration and reduction tower; 2. a circulation tank; 3. a shower pipe; 4. a shower head; 5. a return pipe; 6. a reflux pump; 7. a demister; 8. an air outlet; 9. a medicine feeding pipe; 10. a urea storage tank; 11. an air inlet pipe; 12. a NOx oxidizing assembly; 121. an oxidation reaction chamber; 122. a NOx inlet head; 123. a NOx inlet pipe; 124. an ozone inlet head; 125. an ozone inlet pipe; 13. A drive assembly; 131. a first gear ring; 132. a gear ring II; 133. a motor; 134. a drive bevel gear; 135. a driven bevel gear; 136. a rotating shaft; 137. the gears are driven.

Detailed Description

The technical solution of the present invention will be clearly and completely described below with reference to the specific embodiments. It is to be understood that the disclosed embodiments are merely exemplary of the invention, and are not intended to limit the invention to the precise embodiments disclosed. Based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.

Example (b): the utility model provides a low temperature wet flue gas denitrification facility, as shown in figure 1, including denitration reduction tower 1, the bottom is provided with circulation tank 2 in the denitration reduction tower 1, is equipped with the urea solution that contains organic auxiliary agent in the circulation tank 2, is provided with spray assembly above circulation tank 2, and spray assembly includes three-layer shower 3, is provided with a plurality of shower heads 4 on the shower 3, and shower 3 links to each other with back flow 5, is provided with backwash pump 6 on the back flow 5, backwash pump 6 pumps urea solution to in shower 3, sprays in denitration reduction tower 1 through shower head 4, and urea solution drops to in circulation tank 2 after with the NOx contact reaction in the denitration reduction tower 1. Be provided with defroster 7 in the spray set, the flue gas after urea treatment carries out gas-liquid separation through defroster 7, and clean gas is discharged from gas outlet 8.

As shown in figure 1, the circulating tank 2 is connected with a urea storage tank 10 through a dosing pipe 9, and urea solution containing organic auxiliary agents is continuously supplemented into the circulating tank 2, so that urea with a certain concentration is always kept in the circulating tank 2.

As shown in figure 2 of the drawings, in which, as shown in fig. 3, an air inlet pipe 11 is arranged on the denitration reduction tower 1, an air outlet end of the air inlet pipe 11 is located below the spray assembly, an air inlet end of the air inlet pipe 11 is connected with the NOx oxidation assembly 12, the NOx oxidation assembly 12 includes an oxidation reaction chamber 121, two ends of the oxidation reaction chamber 121 are respectively and rotatably connected with a NOx inlet head 122 and an ozone inlet head 124, one end of the NOx inlet head 122, which is far away from the oxidation reaction chamber 121, is rotatably connected with a NOx inlet pipe 123, the NOx inlet head 122 and the ozone inlet head 124 are connected with the oxidation reaction chamber 121 through a rotary joint, one end of the ozone inlet head 124, which is far away from the oxidation reaction chamber 121, is rotatably connected with an ozone inlet pipe 125, one end of the ozone inlet pipe 125, which is far away from the oxidation reaction chamber 121, is connected with an ozone generator, a driving assembly 13 for driving the NOx inlet head 122 and the ozone inlet head 124 to rotate is arranged on the oxidation reaction chamber 121, and a side wall of the oxidation reaction chamber 121 is connected with the air inlet pipe 11. The NOx and the ozone enter the oxidation reaction chamber 121 through the NOx inlet head and the ozone inlet head 124 respectively, the rotation directions of the NOx inlet head 122 and the ozone inlet head 124 are opposite under the action of the driving assembly 13, and two opposite high-speed airflows collide in the oxidation reaction chamber 121, so that the ozone and the NOx are fully mixed and contacted, and the NOx is fully oxidized.

As shown in fig. 2 and 3, the driving assembly 13 includes a first gear ring 131 fixedly connected to the NOx inlet head 122, and a second gear ring 132 fixedly connected to the ozone inlet head 124, a motor 133 is disposed on the oxidation reaction chamber 121, an output end of the motor 133 is fixedly connected to a drive bevel gear 134, two driven bevel gears 135 are symmetrically disposed on two sides of the drive bevel gear 134, the driven bevel gears 135 are engaged with the drive bevel gear 134, a rotating shaft 136 is fixedly connected to the driven bevel gears 135, a driving gear 137 is fixedly connected to one end of the rotating shaft 136 away from the driven bevel gears 135, the two driving gears 137 are respectively engaged with the first gear ring 131 and the second gear ring 132, and the first gear ring 131, the second gear ring 132 and the driving gear 137 are all helical gears. The driving bevel gear 134 and the two symmetrical driven bevel gears 135 are adopted to drive the NOx air inlet head and the ozone air inlet head 124 to rotate, the NOx air inlet head 122 and the ozone air inlet head 124 can be driven to rotate in opposite directions through the motor 133, the transmission precision of the bevel gears is high, the high-speed rotation of the NOx air inlet head 122 and the ozone air inlet head 124 can be ensured, and the air flow mixing effect is improved.

A low temperature wet flue gas denitration device theory of operation: the flue gas containing NOx enters an oxidation reaction chamber 121 through a NOx inlet head 122 after being pressurized, ozone in an ozone generator enters the oxidation reaction chamber 121 through an ozone inlet head 124 after being pressurized, the NOx inlet head 122 and the ozone inlet head 124 rotate at a high speed in a reverse direction under the action of a driving assembly 13, and two high-speed air flows collide with the oxidation reaction chamber 121 and can be mixed rapidly in an instant, so that the ozone is in rapid contact with the NOx flue gas, and the NOx is fully oxidized; then the oxidized NOx flue gas is introduced into a denitration and reduction tower 1, and the urea solution containing the organic auxiliary agent sprayed from the spray header 4 reacts with the oxidized NOx flue gas to reduce NOx into N2 and CO2, wherein the specific chemical reactions are as follows:

N2O3+H2O→2HNO2

N2O4+H2O→HNO2+HNO3

2NO2+H2O→HNO2+HNO3

2HNO2+(NH2)2CO→2N2+CO2+3H2O

as can be seen from the above mechanism, the removal of NOx is mainly achieved by the oxidation of NO, which is then dissolved in water and chemically reacted with urea to form nitrogen, carbon dioxide and water.

Claims

1. The utility model provides a low temperature wet flue gas denitrification facility which characterized in that: including denitration reduction tower (1), by supreme circulation groove (2), spray assembly, defroster (7) and gas outlet (8) of being provided with down in denitration reduction tower (1), circulation groove (2) link to each other with the defogging subassembly through backwash pump (6) and back flow (5), circulation groove (2) link to each other with urea storage tank (10) through dosing pipe (9), be connected with intake pipe (11) on denitration reduction tower (1), the end of giving vent to anger of intake pipe (11) is located the spray assembly below, the inlet end of intake pipe (11) links to each other with NOx oxidation subassembly (12).

2. The low-temperature wet flue gas denitration device according to claim 1, characterized in that: the spray assembly comprises a plurality of layers of spray pipes (3), a plurality of spray heads (4) are uniformly arranged on the spray pipes (3), and the spray pipes (3) are sequentially connected with a return pipe (5) and a return pump (6).

3. The low-temperature wet flue gas denitration device according to claim 1, characterized in that: the NOx oxidation assembly (12) comprises an oxidation reaction chamber (121), two ends of the oxidation reaction chamber (121) are respectively and rotatably connected with a NOx air inlet head (122) and an ozone air inlet head (124), one end, far away from the oxidation reaction chamber (121), of the NOx air inlet head (122) is rotatably connected with a NOx air inlet pipe (123), one end, far away from the oxidation reaction chamber (121), of the ozone air inlet head (124) is rotatably connected with an ozone air inlet pipe (125), a driving assembly (13) for driving the NOx air inlet head (122) and the ozone air inlet head (124) to rotate is arranged on the oxidation reaction chamber (121), and the side wall of the oxidation reaction chamber (121) is connected with an air inlet pipe (11).

4. The low-temperature wet flue gas denitration device according to claim 3, characterized in that: the driving assembly (13) comprises a first gear ring (131) fixedly connected to the NOx inlet head (122) and a second gear ring (132) fixedly connected to the ozone inlet head (124), a motor (133) is arranged on the oxidation reaction chamber (121), an output end of the motor (133) is fixedly connected with a driving bevel gear (134), two driven bevel gears (135) are symmetrically arranged on two sides of the driving bevel gear (134), the driven bevel gears (135) are meshed with the driving bevel gear (134), a rotating shaft (136) is fixedly connected to the driven bevel gears (135), one ends, far away from the driven bevel gears (135), of the rotating shaft (136) are fixedly connected with driving gears (137), and the two driving gears (137) are respectively meshed with the first gear ring (131) and the second gear ring (132).

5. The low-temperature wet flue gas denitration device according to claim 4, characterized in that: the first gear ring (131), the second gear ring (132) and the driving gear (137) are all helical gears.

6. The low-temperature wet flue gas denitration device according to claim 3, characterized in that: the NOx inlet head (122) and the ozone inlet head (124) are connected with the oxidation reaction chamber (121) through a rotary joint.

7. The low-temperature wet flue gas denitration device according to claim 3, characterized in that: one end of the ozone inlet pipe (125) far away from the oxidation reaction chamber (121) is connected with an ozone generator.