Apparatus, system and method for reducing absorption of nitrogen dioxide by microdroplets

Abstract

The application provides a device, a system and a method for reducing absorption of nitrogen dioxide by microdroplets, and relates to the technical field of environmental gas reduction.The device comprises a nozzle inner tube, a nozzle outer tube, a spring, a water pump and a circulating pool; the water pump pumps the absorption liquid in the circulating pool into the nozzle inner tube, and at the same time, gas enters the gap between the nozzle outer tube and the nozzle inner tube, so that the nozzle inner tube is retracted, and the spring is compressed; the front end of the nozzle inner tube and the front end of the nozzle outer tube form a gap, so that the gas is sprayed out of the gap and combined with the absorption liquid in the nozzle inner tube, and under the action of gas pressure, the absorption liquid is atomized to form microdroplets and sprayed out. The reduction device adopts the form of microdroplets, the microdroplets can greatly increase the gas-liquid contact area, and at the same time, the turbulent motion of the microdroplets also enhances the gas-liquid mixing, so that the denitration efficiency is improved.

Description

Technical Field

[0001] This invention relates to the technical field of environmentally friendly gas reduction, and more particularly to an apparatus, system, and method for reducing and absorbing nitrogen dioxide through microdroplets. Background Technology

[0003] Currently, common denitrification technologies include SCR and SNCR. These technologies mostly employ gas-liquid absorption towers, utilizing processes such as spray absorption or packed absorption to reduce nitrogen oxides in flue gas. However, these traditional methods have many limitations. On the one hand, they require a large amount of solution for absorption, resulting in a large solution consumption, which in turn necessitates larger absorption towers and higher-power circulating pumps to ensure sufficient contact between the gas and solution. This undoubtedly increases the construction and operating costs of the equipment. On the other hand, traditional denitrification technologies have strict requirements for flue gas conditions; even slight deviations can affect denitrification efficiency. Furthermore, ammonia escape is prone to occur, causing secondary pollution.

[0004] Microdroplets, as liquid inclusions at the microscale, possess many unique properties and advantages. The specific surface area of ​​a fluid increases as its size decreases to the micrometer scale, and its fluid behavior differs from that of macroscopic fluids. Microdroplets have an extremely large specific surface area. When pollutant gases come into contact with microdroplets, pollutant molecules transfer from the gas phase to the interior of the droplet. Due to the extremely small size of microdroplets, their total surface area to volume ratio is much larger than that of traditional large droplets, which significantly increases the contact area between gas and liquid, thereby improving mass transfer efficiency. Simultaneously, the movement of microdroplets generates turbulence, further enhancing the mixing and mass transfer rate between gas and liquid. Microdroplets formed through technologies such as nozzle atomization have a longer residence time and a higher collision probability in the airflow, enabling them to fully contact pollutants. Furthermore, the rapid turnover of microdroplets can prevent absorbent saturation and maintain continuous absorption capacity. Summary of the Invention

[0005] In view of the technical problems mentioned in the background section, this invention provides a device, system and method for reducing and absorbing nitrogen dioxide by microdroplets. The invention utilizes a microdroplet spraying device to atomize the absorbent into microdroplets, which can effectively reduce the amount of absorbent used, while reducing the volume of the absorption tower, and greatly reducing construction and operating costs.

[0006] The technical means employed in this invention are as follows:

[0007] A device for absorbing nitrogen dioxide by reducing microdroplets includes: an inner nozzle tube, an outer nozzle tube, a spring, a water pump, and a circulation tank;

[0008] The water pump pumps the absorbent liquid from the circulation tank into the inner tube of the nozzle. Simultaneously, compressed gas enters the gap between the outer tube and the inner tube of the nozzle, causing the inner tube to retract and compress the spring. A gap is formed between the front end of the inner tube and the front end of the outer tube, allowing the compressed gas to be ejected from the gap and merge with the absorbent liquid in the inner tube. Under the action of gas pressure, the absorbent liquid is atomized into micro-droplets and ejected. The gas is any one or a mixture of two or more of air, nitrogen, helium, argon, and carbon dioxide. The gas pressure is 0.3-1.0 MPa.

[0009] Furthermore, the inner nozzle tube is concentrically arranged inside the outer nozzle tube.

[0010] Furthermore, an end face is provided in the middle of the inner tube of the nozzle; the spring is provided between the end face and the cross-section of the tail of the outer tube of the nozzle.

[0011] Furthermore, the inner tube of the nozzle is axially extended and retracted within the outer tube of the nozzle via the spring.

[0012] Furthermore, the absorbent is a mixture of one or more of the following substances: sodium thiosulfate, sodium sulfite, sodium sulfide, ferrous sulfate, diethanolamine, triethanolamine, methanol, and ethanol.

[0013] The present invention also includes a system for reducing and absorbing nitrogen dioxide by microdroplets, comprising: a microdroplet generating unit, an absorbent storage unit, and an absorbent extraction unit; the absorbent stored in the absorbent storage unit is extracted by the absorbent extraction unit, and the absorbent is atomized by the microdroplet generating unit under air pressure to form microdroplets that are ejected.

[0014] Furthermore, the microdroplet generating unit includes: an inner nozzle tube, an outer nozzle tube, and a spring; gas enters the gap between the outer nozzle tube and the inner nozzle tube, causing the inner nozzle tube to retract, thereby compressing the spring; the front end of the inner nozzle tube and the front end of the outer nozzle tube form a gap, allowing gas to be ejected from the gap and merge with the absorbent liquid in the inner nozzle tube. Under the action of air pressure, the absorbent liquid is atomized to form microdroplets that are ejected.

[0015] Furthermore, the absorbent storage unit includes a circulation tank; the circulation tank stores the absorbent.

[0016] Furthermore, the absorbent extraction unit includes a water pump; the water pump pumps the absorbent from the circulation tank into the microdroplet generation unit.

[0017] The present invention also includes a method for the reduction and absorption of nitrogen dioxide by microdroplets, characterized by comprising the following steps:

[0018] Step 1: The water pump pumps the absorbent liquid in the circulation tank into the inner tube of the nozzle;

[0019] Step 2: Gas enters the gap between the outer tube of the nozzle and the inner tube of the nozzle, causing the inner tube of the nozzle to retract, thereby compressing the spring;

[0020] Step 3: A gap is formed between the front end of the inner tube of the nozzle and the front end of the outer tube of the nozzle (2), so that gas will be ejected from the gap;

[0021] Step 4: The gas in step 3 merges with the absorbent liquid in the inner tube of the nozzle, and under the action of air pressure, the absorbent liquid is atomized to form micro-droplets that are sprayed out.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] The reduction device described in this invention adopts the form of microdroplets, which can greatly increase the gas-liquid contact area. At the same time, the turbulent motion of the microdroplets also enhances gas-liquid mixing, thereby improving the denitrification efficiency.

[0024] The apparatus, method, and system of this invention do not require expensive catalysts or complex equipment, resulting in lower initial investment and operating costs. Furthermore, their flexibility allows for precise spraying to the reaction zone, reducing the amount of absorbent needed and further saving costs.

[0025] The device, method, and system of this invention can effectively avoid the ammonia escape problem in traditional denitrification technologies. Through precise control and chemical reaction, it reduces the emission of unreacted ammonia and other substances, thereby reducing secondary pollution to the atmosphere.

[0026] The device of this invention has a simple structure, occupies a small area, is easy to install in industrial sites with limited space, and is convenient to operate and maintain, making it easy to promote and apply. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 This is a schematic diagram of the device structure of the present invention.

[0029] Figure 2 This is a schematic diagram of the method flow of the present invention.

[0030] Figure 3 This is a schematic diagram of the system structure of the present invention.

[0031] Among them, 1 is the inner tube of the nozzle; 2 is the outer tube of the nozzle; 3 is the spring; 4 is the water pump; 5 is the circulation tank; 6 is the absorbent liquid; 7 is the microdroplet generation section; 8 is the absorbent liquid storage section; and 9 is the absorbent liquid extraction section. Detailed Implementation

[0032] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0035] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0036] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention. The directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0037] For ease of description, spatial relative terms such as "above," "over," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation besides the orientation of the device as described in the figures. For example, if the device in the figures is inverted, a device described as "above" or "above" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0038] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0039] like Figure 1 As shown, the present invention provides a device for reducing and absorbing nitrogen dioxide by microdroplets, comprising: an inner nozzle tube 1, an outer nozzle tube 2, a spring 3, a water pump 4, and a circulation tank 5.

[0040] Preferably, in this application, the absorbent liquid in the circulation tank 5 is pumped into the inner tube 1 of the nozzle by the water pump 4. At the same time, gas enters the gap between the outer tube 2 of the nozzle and the inner tube 1 of the nozzle, causing the inner tube 1 of the nozzle to retract and compress the spring 3. The front end of the inner tube 1 of the nozzle and the front end of the outer tube 2 of the nozzle form a gap, so that the gas will be ejected from the gap and merge with the absorbent liquid in the inner tube 1 of the nozzle. Under the action of air pressure, the absorbent liquid is atomized and formed into micro-droplets that are ejected.

[0041] In this application, the gas includes, but is not limited to, any one or a mixture of two or more of air, nitrogen, helium, argon, and carbon dioxide; the gas pressure is 0.3-1.0 MPa.

[0042] In a preferred embodiment, in this application, the inner nozzle tube 1 is concentrically disposed within the outer nozzle tube 2. This arrangement allows for better compression control between the inner and outer tubes, while effectively reducing the overall size of the device.

[0043] like Figure 1 As shown, the inner nozzle tube 1 has an end face in the middle; the spring 3 is disposed between the end face and the cross-section of the tail of the outer nozzle tube 2. The spring 3 enables the axial extension and retraction of the inner nozzle tube 1 within the outer nozzle tube 2. When gas enters the gap formed between the front end of the inner nozzle tube 1 and the front end of the outer nozzle tube 2, the gas pushes the inner nozzle tube 1 to move, thereby compressing the spring 3, allowing the gas and liquid to mix further.

[0044] In a preferred embodiment, to achieve better nitrogen dioxide recovery, the absorbent in this application is a reducing agent. This can be understood as the absorbent being one or a mixture of several substances selected from sodium thiosulfate, sodium sulfite, sodium sulfide, ferrous sulfate, diethanolamine, triethanolamine, methanol, and ethanol.

[0045] As a preferred implementation method, such as Figure 2 As shown, this application also includes a system for reducing and absorbing nitrogen dioxide through microdroplets, comprising: a microdroplet generating unit, an absorbent storage unit, and an absorbent extraction unit; the absorbent stored in the absorbent storage unit is extracted by the absorbent extraction unit, and the absorbent is atomized by the microdroplet generating unit under air pressure to form microdroplets that are ejected.

[0046] Preferably, the microdroplet generating unit includes: an inner nozzle tube 1, an outer nozzle tube 2, and a spring 3; gas enters the gap between the outer nozzle tube 2 and the inner nozzle tube 1, causing the inner nozzle tube 1 to retract, thereby compressing the spring 3; the front end of the inner nozzle tube 1 and the front end of the outer nozzle tube 2 form a gap, allowing gas to be ejected from the gap and merge with the absorbent liquid in the inner nozzle tube 1, atomizing the absorbent liquid under the action of air pressure to form microdroplets.

[0047] Preferably, the absorbent storage unit includes a circulation tank 5; the circulation tank 5 stores the absorbent. In this application, the absorbent is one or a mixture of several substances selected from sodium thiosulfate, sodium sulfite, sodium sulfide, ferrous sulfate, diethanolamine, triethanolamine, methanol, and ethanol.

[0048] Preferably, the absorbent extraction unit includes a water pump 4; the water pump 4 pumps the absorbent from the circulation tank 5 into the microdroplet generation unit.

[0049] Further, preferably, such as Figure 3 As shown, this application also includes a method for reducing and absorbing nitrogen dioxide via microdroplets, comprising the following steps:

[0050] Step 1: Pump 4 pumps the absorbent liquid in the circulation tank 5 into the inner tube of the nozzle;

[0051] Step 2: Gas enters the gap between the outer tube 2 of the nozzle and the inner tube 1 of the nozzle, causing the inner tube 1 of the nozzle to retract, thereby compressing the spring 3;

[0052] Step 3: A gap is formed between the front end of the inner nozzle tube 1 and the front end of the outer nozzle tube 2, allowing gas to be ejected from the gap;

[0053] Step 4: The gas in step 3 merges with the absorbent liquid in the inner tube 1 of the nozzle, and under the action of air pressure, the absorbent liquid is atomized to form micro-droplets and sprayed out.

[0054] Comparative Example 1:

[0055] 1. Setting up the environment for the implementation example

[0056] Laboratory conditions: Small-scale experiments conducted at ambient temperature and pressure inside a laboratory fume hood.

[0057] 2. Material Preparation

[0058] Ordinary glass plate absorption bottle

[0059] Microdroplet ejection device

[0060] Absorption solutions: ammonia water, NaOH solution, Na2CO3 solution, Na2SO3 solution, urea solution.

[0061] Nitrogen oxides gas: supplied via cylinders, with a specific concentration of 612 mg / m³. 3 .

[0062] Gas flow meter: Used to control gas flow.

[0063] Gas detector: Used to monitor the concentration of nitrogen oxides.

[0064] The flow rate of nitrogen oxide gas was controlled using a gas flow meter. At 60°C, the gas was introduced into a standard glass plate absorption bottle containing ammonia absorbent, ensuring sufficient contact. After 10 minutes, the nitrogen oxide concentration was observed to decrease to 213 mg / m³. 3 The nitrogen oxide removal efficiency was 65.20%.

[0065] Example 1:

[0066] The flow rate of nitrogen oxide gas was controlled using a gas flow meter. The gas was introduced into the reaction flask at 60°C, while ammonia absorbent was simultaneously sprayed into the flask using a micro-droplet injection device to ensure sufficient contact. The nitrogen oxide concentration was observed to decrease to 78 mg / m³ after 10 minutes. 3 The nitrogen oxide removal efficiency was 87.25%.

[0067] Example 2:

[0068] The difference from Example 1 is that in the above operation steps, the absorbent is NaOH, and the nitric oxide concentration drops to 107 mg / m³. 3 The nitrogen oxide removal efficiency was 82.52%.

[0069] Example 3:

[0070] The difference from Example 1 is that, in the above operation steps, the absorbent is Na2CO3, at which point the nitric oxide concentration drops to 187 mg / m³. 3 The nitrogen oxide removal efficiency was 69.44%.

[0071] Example 4:

[0072] The difference from Example 1 is that, in the above operation steps, the absorbent is Na2SO3, at which point the nitric oxide concentration drops to 201 mg / m³. 3 The nitrogen oxide removal efficiency was 67.16%.

[0073] Example 5:

[0074] The difference from Example 1 is that, in the above operation steps, the absorbent is a urea solution, and the nitric oxide concentration drops to 54 mg / m³. 3 The nitrogen oxide removal efficiency was 91.18%.

[0075] Table 1. Microdroplet denitrification effect in Examples 1-5

[0076] Absorbent liquid Nitrogen oxide removal efficiency / % Comparative Example 1 Absorption bottle + ammonia 65.20 Example 1 ammonia 87.25 Example 2 NaOH 82.52 Example 3 <![CDATA[Na2CO3]]> 69.44 Example 4 <![CDATA[Na2SO3]]> 67.16 Example 5 Urea 91.18

[0077] Based on the treatment effects of Examples 1-5, the small-scale laboratory experiments have verified the feasibility of the present invention, providing basic data and operating parameters for further pilot-scale and industrial applications.

[0078] Example 6

[0079] 1. Implementation Environment

[0080] Factory conditions: A medium-scale test conducted at a waste lead recycling plant under normal temperature and pressure.

[0081] 2. Material Preparation

[0082] 8 sets of microdroplet jetting devices

[0083] Absorption solution: ammonia.

[0084] 3. Operating Steps

[0085] The factory originally had one conventional spray tower with eight ordinary spray heads, used for ammonia denitrification. The tower was designed for an ammonia circulation rate of 40,000 L / h and a nitrogen oxide concentration of 50-300 mg / m³. 3 ,

[0086] In this renovation project, the original eight ordinary spray heads were dismantled and the spray device of this scheme was installed in their original positions. Ammonia water was added to the circulation tower as the absorbent, and the absorbent was pumped into the spray device of the spray tower.

[0087] Through the modifications in this embodiment, the ammonia consumption is reduced to 1000 L / h, and the nitrogen oxide concentration is reduced to 80 mg / m³. 3 The following measures were implemented: Absorbent solution was reduced by 97%, and nitrogen oxide emissions were reduced by 55%.

[0088] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for absorbing nitrogen dioxide by reducing it through microdroplets, characterized in that, include: Nozzle inner tube (1), nozzle outer tube (2), spring (3), water pump (4) and circulation tank (5); The water pump (4) pumps the absorbent liquid in the circulation tank (5) into the inner tube (1) of the nozzle. At the same time, gas enters the gap between the outer tube (2) of the nozzle and the inner tube (1) of the nozzle, causing the inner tube (1) of the nozzle to retract, thereby compressing the spring (3). The front end of the inner tube (1) of the nozzle and the front end of the outer tube (2) of the nozzle form a gap, so that the gas will be ejected from the gap and merge with the absorbent liquid in the inner tube (1) of the nozzle. Under the action of gas pressure, the absorbent liquid is atomized and formed into micro-droplets. The gas is any one or a mixture of two or more of air, nitrogen, helium, argon and carbon dioxide. The gas pressure is 0.3-1.0 MPa.

2. The device for absorbing nitrogen dioxide by reducing microdroplets according to claim 1, characterized in that, The inner tube (1) of the nozzle is concentrically arranged inside the outer tube (2) of the nozzle.

3. The device for absorbing nitrogen dioxide by reducing microdroplets according to claim 1, characterized in that, The nozzle inner tube (1) has an end face in the middle; the spring (3) is provided between the end face and the cross-section of the nozzle outer tube (2) at the tail.

4. The device for absorbing nitrogen dioxide by reducing microdroplets according to claim 1 or 3, characterized in that, The inner tube (1) of the nozzle is axially extended and retracted in the outer tube (2) of the nozzle by means of the spring (3).

5. The device for absorbing nitrogen dioxide by reducing microdroplets according to claim 1, characterized in that, The absorbent is a mixture of one or more of the following substances: sodium thiosulfate, sodium sulfite, sodium sulfide, ferrous sulfate, diethanolamine, triethanolamine, methanol, and ethanol.

6. A system for the reduction and absorption of nitrogen dioxide via microdroplets, using the apparatus described in any one of claims 1-5, characterized in that, include: Microdroplet generation section, absorbent storage section, and absorbent extraction section; The absorbent liquid stored in the absorbent liquid storage unit is extracted by the absorbent liquid extraction unit, and then atomized by the microdroplet generating unit under air pressure to form microdroplets that are sprayed out.

7. The system for absorbing nitrogen dioxide by reducing microdroplets according to claim 6, characterized in that, The microdroplet generating unit includes: an inner nozzle tube (1), an outer nozzle tube (2), and a spring (3); gas enters the gap between the outer nozzle tube (2) and the inner nozzle tube (1), causing the inner nozzle tube (1) to retract, thereby compressing the spring (3); the front end of the inner nozzle tube (1) and the front end of the outer nozzle tube (2) form a gap, allowing gas to be ejected from the gap and merge with the absorbent liquid in the inner nozzle tube (1). Under the action of air pressure, the absorbent liquid is atomized to form microdroplets that are ejected.

8. The system for reducing and absorbing nitrogen dioxide via microdroplets according to claim 6, characterized in that, The absorbent storage unit includes a circulation tank (5); the circulation tank (5) stores the absorbent.

9. A system for the reduction and absorption of nitrogen dioxide via microdroplets according to claim 6, characterized in that, The absorbent extraction unit includes a water pump (4); the water pump (4) pumps the absorbent in the circulation tank (5) into the microdroplet generation unit.

10. A method for the reduction and absorption of nitrogen dioxide by microdroplets, using the apparatus described in any one of claims 1-5, characterized in that, Includes the following steps: Step 1: The water pump (4) pumps the absorbent liquid in the circulation tank (5) into the inner tube of the nozzle; Step 2: Gas enters the gap between the outer tube (2) of the nozzle and the inner tube (1) of the nozzle, causing the inner tube (1) of the nozzle to retract, thereby compressing the spring (3); Step 3: A gap is formed between the front end of the inner tube (1) of the nozzle and the front end of the outer tube (2) of the nozzle, so that gas will be ejected from the gap; Step 4: The gas in step 3 merges with the absorbent liquid in the inner tube (1) of the nozzle, and under the action of air pressure, the absorbent liquid is atomized to form micro-droplets and sprayed out.

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