Asphalt mixing station flue gas purification system

Abstract

The present invention discloses a flue gas purification system for an asphalt mixing plant. The system comprises an asphalt mixture mixing silo, a flue gas extraction pump, a first purification component, a second purification component, and a third purification component, all interconnected in sequence. The flue gas extraction pump extracts asphalt flue gas from the asphalt mixture mixing silo, causing the asphalt flue gas to flow sequentially through the first, second, and third purification components. The first purification component removes dust and dries the asphalt flue gas, the second purification component performs adsorption-thermal catalytic treatment on the asphalt flue gas, and the third purification component selectively adsorbs the asphalt flue gas. The asphalt mixing plant flue gas purification system provided by the present invention can achieve low-energy, safe, and efficient purification of harmful asphalt flue gas from asphalt mixing plants, effectively reducing the adverse impact of asphalt mixing plant flue gas on the ecological environment.

Description

Technical Field

[0001] The present invention relates to the field of road engineering construction, and in particular to a flue gas purification and treatment system for an asphalt mixing station. Background Art

[0002] Hot-mix asphalt mixtures generate a large amount of harmful asphalt fumes during their production. Modified asphalt mixtures, in particular, are typically heated and mixed at higher temperatures, making harmful asphalt fume emissions more severe. Research has shown that as mixing temperature increases, total harmful asphalt fume emissions increase in a binomial fashion.

[0003] The harmful asphalt fume produced by asphalt mixing plants is complex, primarily consisting of alkane derivatives, sulfur- and nitrogen-containing compounds, polycyclic aromatic hydrocarbons (PAHs), heterocycles, and black smoke particles. These substances pose potential threats to both humans and the environment. Direct emissions into the air can trigger environmental pollution problems such as the greenhouse effect, acid rain, and smog. PAHs are the most harmful, containing a large number of carcinogens and causing significant damage to the human nervous system.

[0004] Currently, asphalt mixing plants primarily use bag collection and direct combustion methods to treat harmful asphalt fumes. While the bag collection method is effective for treating black smoke particles, it is less effective for treating alkane derivatives, sulfur- and nitrogen-containing compounds, and polycyclic aromatic hydrocarbons (PAHs), and thus fails to effectively address volatile organic compound (VOC) emissions. Direct combustion, on the other hand, requires additional fuel, resulting in high energy consumption and operating costs. Furthermore, the open flame poses safety risks and is less effective for treating halogenated and acidic gases.

[0005] Therefore, in view of the problems existing in the current asphalt mixing plant flue gas purification treatment method, such as incomplete treatment, high energy consumption, and poor safety, the present invention provides an asphalt mixing plant flue gas purification treatment system, which can use lower energy consumption to safely and efficiently treat the harmful asphalt flue gas from the asphalt mixing plant. Summary of the Invention

[0006] The main purpose of the present invention is to propose a flue gas purification and treatment system for an asphalt mixing plant, aiming to provide a treatment system that can use low energy consumption, safely and efficiently treat harmful asphalt flue gas from an asphalt mixing plant.

[0007] To achieve the above-mentioned object, the present invention proposes a flue gas purification system for an asphalt mixing plant, comprising an asphalt mixture mixing bin, a flue gas extraction pump, a first purification component, a second purification component, and a third purification component connected in sequence;

[0008] Among them, the flue gas extraction pump is used to extract the asphalt flue gas in the asphalt mixture mixing bin so that the asphalt flue gas flows through the first purification treatment component, the second purification treatment component and the third purification treatment component in sequence. The first purification treatment component is used to perform dust removal and drying treatment on the asphalt flue gas, the second purification treatment component is used to perform adsorption-thermal catalytic treatment on the asphalt flue gas, and the third purification treatment component is used to selectively adsorb the asphalt flue gas.

[0009] Optionally, the first purification component includes:

[0010] The first purification cylinder has an air inlet end and an air outlet end opposite to each other, and a first air filter, a molecular sieve desiccant filling layer, and a second air filter are sequentially arranged in the inner cavity of the first purification cylinder from the air inlet end to the air outlet end.

[0011] a first gas delivery end plate, provided at the gas inlet end of the first purification cylinder, and having a first gas delivery hole in communication with the inner cavity of the first purification cylinder formed in the middle of the first gas delivery end plate, the first gas delivery hole being in communication with the flue gas extraction pump via a first gas delivery conduit; and

[0012] The second gas delivery end plate is arranged at the gas outlet end of the first purification cylinder, and a second gas delivery hole connected to the inner cavity of the first purification cylinder is formed in the middle of the second gas delivery end plate. The second gas delivery hole is connected to the second purification treatment component through a second gas delivery conduit.

[0013] Optionally, the first purification cartridge is sealed to the first gas delivery end plate; and / or,

[0014] The first purification cylinder is sealed to the second gas transmission end plate; and / or,

[0015] The first purification cylinder is made of borosilicate glass.

[0016] Optionally, the first purification component further includes a first threaded fastener, and two ends of the first threaded fastener are respectively connected to the first gas delivery end plate and the second gas delivery end plate to relatively fix the first gas delivery end plate and the second gas delivery end plate.

[0017] Optionally, the second purification treatment component includes:

[0018] The second purification cylinder has an air inlet end and an air outlet end that are oppositely arranged. An oil inlet and an oil outlet are formed on the side of the second purification cylinder. An oil guide pipe for transmitting heat transfer oil is provided in the second purification cylinder. One end of the oil guide pipe enters the second purification cylinder through the oil inlet, and the other end exits the second purification cylinder through the oil outlet. A molecular sieve carrier filling layer is provided in an area of the inner cavity of the second purification cylinder surrounding the oil guide pipe.

[0019] a third gas delivery end plate, provided at the gas inlet end of the second purification cylinder, and having a third gas delivery hole formed in the middle portion thereof, communicating with the inner cavity of the second purification cylinder, and the third gas delivery hole being communicated with the first purification cylinder via a second gas delivery conduit; and

[0020] The fourth gas delivery end plate is arranged at the gas outlet end of the second purification cylinder, and a fourth gas delivery hole connected to the inner cavity of the second purification cylinder is formed in the middle of the fourth gas delivery end plate. The fourth gas delivery hole is connected to the third purification treatment component through a third gas delivery conduit.

[0021] Optionally, the material used to form the molecular sieve support filling layer includes a first material, wherein the first material includes a molecular sieve support and an iron-manganese-cerium ternary composite oxide catalyst supported on the molecular sieve support; and / or,

[0022] The oil guide pipe is arranged to extend in a spiral shape along the direction from the air inlet end to the air outlet end of the second purification cylinder; and / or,

[0023] The air inlet end and the air outlet end of the oil guide pipe are connected to the heat transfer oil channel of the asphalt mixture mixing bin to form a circulation passage.

[0024] Optionally, the second purification cartridge is sealedly connected to the third gas transmission end plate; and / or,

[0025] The second purification cylinder is sealed and connected to the fourth gas transmission end plate; and / or,

[0026] The material of the second purification cartridge includes quartz glass; and / or,

[0027] The second purification component further includes a second threaded fastener, the two ends of which are respectively connected to the third gas delivery end plate and the fourth gas delivery end plate, so that the third gas delivery end plate and the fourth gas delivery end plate are relatively fixed.

[0028] Optionally, the third purification treatment component includes:

[0029] A third purification cartridge has an air inlet end and an air outlet end opposite to each other, wherein an organic molecular sieve adsorbent filling layer is provided in the inner cavity of the first purification cartridge;

[0030] a fifth gas delivery end plate, disposed at the gas inlet end of the third purification cylinder, and having a fifth gas delivery hole formed in the middle portion thereof, communicating with the inner cavity of the third purification cylinder, the fifth gas delivery hole being in communication with the second purification treatment assembly via a third gas delivery conduit; and

[0031] The sixth gas delivery end plate is provided at the gas outlet end of the third purification cylinder, and a sixth gas delivery hole communicating with the inner cavity of the third purification cylinder is formed in the middle of the sixth gas delivery end plate, and the sixth gas delivery hole is connected with the fourth gas delivery conduit.

[0032] Optionally, the material used to form the organic molecular sieve adsorbent filling layer includes a second material, and the second material includes a molecular sieve and an organic polymer film coated on the surface of the molecular sieve.

[0033] Optionally, the third purification cartridge is sealedly connected to the fifth gas transmission end plate; and / or,

[0034] The third purification cylinder is sealed and connected to the sixth gas transmission end plate; and / or,

[0035] The material of the third purification cartridge includes borosilicate glass; and / or,

[0036] The third purification component further includes a third threaded fastener, the two ends of which are respectively connected to the fifth gas delivery end plate and the sixth gas delivery end plate, so that the fifth gas delivery end plate and the sixth gas delivery end plate are relatively fixed.

[0037] In the technical solution of the present invention, the asphalt mixing station flue gas purification system includes an asphalt mixture mixing bin, a flue gas extraction pump, a first purification treatment component, a second purification treatment component and a third purification treatment component connected in sequence. When purifying the asphalt flue gas in the asphalt mixture mixing bin, the flue gas extraction pump first extracts the asphalt flue gas in the asphalt mixture mixing bin, so that the asphalt flue gas flows through the first purification treatment component, the second purification treatment component and the third purification treatment component in sequence. The first purification treatment component performs dust removal and drying treatment on the asphalt flue gas, the second purification treatment component performs adsorption-thermal catalysis treatment on the asphalt flue gas, and the third purification treatment component performs selective adsorption on the asphalt flue gas, thereby achieving purification of the asphalt flue gas. The flue gas purification treatment system of the asphalt mixing station fully considers the unique properties of the asphalt mixing station's own process, and sequentially performs preliminary filtration (dust removal and drying treatment of the first purification treatment component), deep adsorption-thermal catalysis (adsorption-thermal catalysis treatment of the second purification treatment component), and residual selective adsorption (selective adsorption of the third purification treatment component) on the asphalt flue gas. This achieves low-energy, safe and efficient purification of harmful asphalt flue gas from the asphalt mixing station, effectively reducing the adverse effects of the flue gas from the asphalt mixing station on the ecological environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0039] Figure 1 This is a structural schematic diagram of an embodiment of the asphalt mixing plant flue gas purification system provided by the present invention;

[0040] Figure 2 for Figure 1 A schematic diagram of the partial structure of the first purification treatment component;

[0041] Figure 3 for Figure 1 A schematic diagram of the partial structure of the second purification treatment component;

[0042] Figure 4 for Figure 1 Schematic diagram of the partial structure of the third purification treatment component.

[0043] Description of Figure Numbers:

[0044] Label name Label name 100 Asphalt mixing plant flue gas purification system 411 Oil inlet 1 Asphalt mixing silo 412 Oil outlet 2 Flue gas extraction pump 413 Oil pipe 21 Fifth gas supply duct 414 Molecular sieve carrier filling layer 3 First purification treatment component 42 The third gas transmission end plate 31 First purification cartridge 43 Fourth gas transmission end plate 311 First air filter 431 The third gas supply duct 312 Molecular sieve desiccant filling layer 44 Second threaded fastener 313 Second air filter 5 The third purification component 32 First gas transmission end plate 51 The third purification cartridge 321 First gas duct 511 Organic molecular sieve adsorbent filling layer 33 Second gas transmission end plate 52 Fifth gas transmission end plate 331 Second gas supply conduit 53 Sixth gas transmission end plate 34 First threaded fastener 531 Fourth gas pipeline 4 Second purification component 54 Third threaded fastener 41 Second purification cartridge

[0045] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0046] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0047] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indications will also change accordingly.

[0048] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present invention, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the meaning of "and / or" appearing throughout the text includes three parallel schemes. Taking "A and / or B" as an example, it includes scheme A, or scheme B, or a scheme in which A and B are satisfied at the same time. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0049] The present invention provides a flue gas purification system for an asphalt mixing station. Figures 1 to 4 This is an embodiment of the asphalt mixing plant flue gas purification system provided by the present invention.

[0050] like Figures 1 to 4 As shown, the asphalt mixing plant flue gas purification system 100 includes an asphalt mixture mixing chamber 1, a flue gas extraction pump 2, a first purification treatment component 3, a second purification treatment component 4 and a third purification treatment component 5 connected in sequence; wherein, the flue gas extraction pump 2 is used to extract the asphalt flue gas in the asphalt mixture mixing chamber 1, so that the asphalt flue gas flows through the first purification treatment component 3, the second purification treatment component 4 and the third purification treatment component 5 in sequence, the first purification treatment component 3 is used to remove dust and dry the asphalt flue gas, the second purification treatment component 4 is used to perform adsorption-thermal catalytic treatment on the asphalt flue gas, and the third purification treatment component 5 is used to selectively adsorb the asphalt flue gas.

[0051] In the technical solution of the present invention, the asphalt mixing station flue gas purification system 100 includes an asphalt mixture mixing bin 1, a flue gas extraction pump 2, a first purification treatment component 3, a second purification treatment component 4 and a third purification treatment component 5 connected in sequence. When purifying the asphalt flue gas in the asphalt mixture mixing bin 1, the flue gas extraction pump 2 first extracts the asphalt flue gas in the asphalt mixture mixing bin 1, so that the asphalt flue gas flows through the first purification treatment component 3, the second purification treatment component 4 and the third purification treatment component 5 in sequence. The first purification treatment component 3 performs dust removal and drying treatment on the asphalt flue gas, the second purification treatment component 4 performs adsorption-thermal catalysis treatment on the asphalt flue gas, and the third purification treatment component 5 performs selective adsorption on the asphalt flue gas, thereby achieving purification of the asphalt flue gas. The asphalt mixing plant flue gas purification system 100 fully considers the unique properties of the asphalt mixing plant's own process, and sequentially performs a triple purification treatment process on the asphalt flue gas, namely, preliminary filtration (dust removal and drying treatment in the first purification treatment component 3), deep adsorption-thermal catalysis (adsorption-thermal catalysis treatment in the second purification treatment component 4), and residual selective adsorption (selective adsorption in the third purification treatment component 5). This achieves low-energy, safe, and efficient purification of harmful asphalt flue gas from the asphalt mixing plant, effectively reducing the adverse effects of the flue gas from the asphalt mixing plant on the ecological environment.

[0052] Specifically, in an embodiment of the present invention, the first purification treatment component 3 includes a first purification cylinder 31, a first air delivery end plate 32 and a second air delivery end plate 33. The first purification cylinder 31 has an air inlet end and an air outlet end arranged opposite to each other. The inner cavity of the first purification cylinder 31 is provided with a first air filter 311, a molecular sieve desiccant filling layer 312 and a second air filter 313 in sequence from the air inlet end to the air outlet end. The first air delivery end plate 32 is provided at the air inlet end of the first purification cylinder 31, and a first air delivery hole communicating with the inner cavity of the first purification cylinder 31 is formed in the middle of the first air delivery end plate 32. The first air delivery hole is connected to the flue gas extraction pump 2 through a first air delivery conduit 321. The second air delivery end plate 33 is provided at the air outlet end of the first purification cylinder 31, and a second air delivery hole communicating with the inner cavity of the first purification cylinder 31 is formed in the middle of the second air delivery end plate 33. The second air delivery hole is connected to the second purification treatment component 4 through a second air delivery conduit 331. In this manner, after the asphalt fume enters the first purification cylinder 31, the filtering effects of the first air filter 311 and the second air filter 313 remove dust from the asphalt fume. The drying effect of the molecular sieve desiccant in the molecular sieve desiccant filling layer 312 also dries the asphalt fume, allowing the first purification component 3 to effectively filter the asphalt fume. More specifically, the first air filter 311 and the second air filter 313 are both 80mm thick H13 fiberglass high-temperature resistant and high-efficiency filters. The molecular sieve desiccant used to form the molecular sieve desiccant filling layer 312 is a 4A molecular sieve with a particle size of 3-5mm and a silicon-to-aluminum ratio of 200%. This provides a more effective initial filtration of the asphalt fume.

[0053] Furthermore, the first purification cartridge 31 is sealedly connected to the first gas transmission end plate 32; and / or, the first purification cartridge 31 is sealedly connected to the second gas transmission end plate 33; and / or, the material of the first purification cartridge 31 includes high borosilicate glass. The above features can be set selectively or simultaneously. As a preferred embodiment of the present invention, the above features are simultaneously present, which can make the sealing of the first purification treatment component 3 better, thereby improving the filtering effect of asphalt fume. It can be understood that the present invention does not limit the specific method of sealing the first purification cartridge 31 and the first gas transmission end plate 32. For example, the first purification cartridge 31 and the first gas transmission end plate 32 are threadedly connected to achieve a sealed connection. Specifically, an internal thread is provided on the first purification cartridge 31, and an external thread is provided on the first gas transmission end plate 32. The sealed connection between the first purification cartridge 31 and the first gas transmission end plate 32 is achieved by screwing the internal thread and the external thread. It is understandable that the present invention does not limit the specific manner in which the first purification cylinder 31 and the second gas transmission end plate 33 are sealed together. It is understandable that, similar to the sealing connection between the first purification cylinder 31 and the first gas transmission end plate 32, the present invention does not limit the specific manner in which the first purification cylinder 31 and the second gas transmission end plate 33 are sealed together.

[0054] Furthermore, the first purification component 3 also includes a first threaded fastener 34, the two ends of which are respectively connected to the first gas delivery end plate 32 and the second gas delivery end plate 33, so that the first gas delivery end plate 32 and the second gas delivery end plate 33 are relatively fixed. This arrangement allows the first gas delivery end plate 32 and the second gas delivery end plate 33 to be firmly fastened together, thereby improving the reliability of the first purification component 3. There is no restriction on the specific structure of the first threaded fastener 34, which can be a screw, a stainless steel column, etc. There is no restriction on the specific method of connecting the first threaded fastener 34 to the first gas delivery end plate 32 (or the second gas delivery end plate 33), which can be a welding connection or a threaded connection, etc. There is no restriction on the specific number of the first threaded fasteners 34. In an embodiment of the present invention, six first threaded fasteners 34 are provided, and the six first threaded fasteners 34 are evenly distributed at an angle of 60° along the circumference of the first purification cylinder 31.

[0055] Specifically, in the embodiment of the present invention, the second purification treatment component 4 includes a second purification cylinder 41, a third gas delivery end plate 42 and a fourth gas delivery end plate 43. The second purification cylinder 41 has an air inlet end and an air outlet end that are oppositely arranged. The side of the second purification cylinder 41 is provided with an oil inlet 411 and an oil outlet 412. The second purification cylinder 41 is provided with an oil guide pipe 413 for transmitting heat transfer oil. One end of the oil guide pipe 413 passes through the second purification cylinder 41 through the oil inlet 411, and the other end passes through the second purification cylinder 41 through the oil outlet 412. The inner cavity of the second purification cylinder 41 is located in the oil guide pipe 4 13 is provided with a molecular sieve carrier filling layer 414 in the area around the third gas delivery end plate 42, the third gas delivery end plate 42 is provided at the gas inlet end of the second purification cylinder 41, and the middle of the third gas delivery end plate 42 is formed with a third gas delivery hole connected to the inner cavity of the second purification cylinder 41, the third gas delivery hole is connected to the first purification cylinder 31 through the second gas delivery conduit 331, the fourth gas delivery end plate 43 is provided at the gas outlet end of the second purification cylinder 41, and the middle of the fourth gas delivery end plate 43 is formed with a fourth gas delivery hole connected to the inner cavity of the second purification cylinder 41, the fourth gas delivery hole is connected to the third purification treatment component 5 through the third gas delivery conduit 431. In this way, after the asphalt flue gas that has been preliminarily filtered by the first purification treatment component 3 enters the second purification cylinder 41, the heat transfer oil in the oil guide pipe 413 circulates, and the heat carried by the heat transfer oil realizes the heating of the second purification treatment component 4, and the molecular sieve carrier in the molecular sieve carrier filling layer 414 realizes flameless combustion of the asphalt flue gas based on the adsorption-thermal catalysis principle, converts the asphalt flue gas into CO2 and H2O, and releases heat. The released heat and the heat carried by the heat transfer oil realize a continuous reaction of adsorption-thermal catalysis, thereby realizing adsorption-thermal catalysis treatment of the asphalt flue gas, so that the second purification treatment component 4 can better deeply adsorb and thermally catalyze the asphalt flue gas.

[0056] Furthermore, the material used to form the molecular sieve support filling layer 414 includes a first material, which includes a molecular sieve support and an iron-manganese-cerium ternary composite oxide catalyst supported on the molecular sieve support. This improves the adsorption-thermal catalytic effect of the molecular sieve support filling layer 414. Specifically, the molecular sieve support is a USY molecular sieve with a silicon-aluminum ratio of 150%. The ratio of the oxides in the iron-manganese-cerium ternary composite oxide catalyst is 2:2:1. The loading ratio of the iron-manganese-cerium ternary composite oxide catalyst on the molecular sieve support is 8-15%, preferably 10%. The specific preparation process of the first material is as follows: First, a USY molecular sieve with a silicon-aluminum ratio of 150% is selected, soaked in a nitric acid solution for 20 hours, filtered, washed to neutrality, and placed in a 110°C oven for drying for 24 hours; secondly, iron nitrate and manganese solutions are used as iron and manganese sources, and cerium nitrate hexahydrate is used as a cerium source, and they are dissolved in deionized water in a molar ratio of 2:2:1 to prepare an impregnation solution; then, the treated molecular sieve is placed in a container, and the calculated impregnation solution is added. After stirring evenly, it is allowed to stand in a 70°C water bath for 24 hours, the liquid is evaporated, and it is dried at 105°C for 24 hours; finally, the obtained solid is calcined in a 450°C combustion furnace for 4 hours to obtain the first material.

[0057] Furthermore, the oil guide pipe 413 is spirally extended from the air inlet end to the air outlet end of the second purification cylinder 41 , so that the heat transfer oil in the oil guide pipe 413 flows in a spiral manner, which better heats the second purification treatment component 4 .

[0058] When the asphalt mixture mixing bin 1 is working, the heat transfer oil will flow through the heat transfer oil channel therein. In the embodiment of the present invention, the air inlet and air outlet ends of the oil guide pipe 413 are connected to the heat transfer oil channel of the asphalt mixture mixing bin 1 to form a circulation passage, that is, the heat transfer oil in the heat transfer oil channel of the asphalt mixture mixing bin 1 is introduced into the oil guide pipe 413, realizing the secondary utilization of the heat transfer oil in the heat transfer oil channel of the asphalt mixture mixing bin 1, which is beneficial to cost saving.

[0059] Furthermore, the second purification cartridge 41 is sealedly connected to the third gas transmission end plate 42; and / or, the second purification cartridge 41 is sealedly connected to the fourth gas transmission end plate 43; and / or, the material of the second purification cartridge 41 includes quartz glass. The above features can be set selectively or simultaneously. As a preferred embodiment of the present invention, the above features are present simultaneously, which can make the second purification treatment component 4 more sealed, thereby improving the adsorption-thermal catalytic effect on asphalt flue gas. It is understandable that the present invention does not limit the specific method of sealing the second purification cartridge 41 and the third gas transmission end plate 42. For example, the second purification cartridge 41 and the third gas transmission end plate 42 are threadedly connected to achieve a sealed connection. Specifically, an internal thread is provided on the second purification cartridge 41, and an external thread is provided on the third gas transmission end plate 42. The sealed connection between the second purification cartridge 41 and the third gas transmission end plate 42 is achieved by screwing the internal thread and the external thread together. It is understandable that, similar to the sealed connection between the second purification cartridge 41 and the third gas delivery end plate 42 , the present invention does not limit the specific manner of the sealed connection between the second purification cartridge 41 and the fourth gas delivery end plate 43 .

[0060] Furthermore, the second purification component 4 also includes a second threaded fastener 44, the two ends of which are respectively connected to the third gas delivery end plate 42 and the fourth gas delivery end plate 43, so that the third gas delivery end plate 42 and the fourth gas delivery end plate 43 are relatively fixed. This arrangement allows the third gas delivery end plate 42 and the fourth gas delivery end plate 43 to be firmly fastened together, thereby improving the reliability of the second purification component 4. There is no restriction on the specific structure of the second threaded fastener 44, which can be a screw, a stainless steel column, etc. There is no restriction on the specific method of connecting the second threaded fastener 44 to the third gas delivery end plate 42 (or the fourth gas delivery end plate 43), which can be a welding connection or a threaded connection, etc. There is no restriction on the specific number of the second threaded fasteners 44. In the embodiment of the present invention, six second threaded fasteners 44 are provided, and the six second threaded fasteners 44 are evenly distributed at an angle of 60° along the circumference of the second purification cylinder 41.

[0061] Specifically, in an embodiment of the present invention, the third purification treatment component 5 includes a third purification cylinder 51, a fifth gas delivery end plate 52 and a sixth gas delivery end plate 53. The third purification cylinder 51 has an air inlet end and an air outlet end arranged opposite to each other. An organic molecular sieve adsorbent filling layer 511 is provided in the inner cavity of the first purification cylinder 31. The fifth gas delivery end plate 52 is provided at the air inlet end of the third purification cylinder 51, and a fifth gas delivery hole communicating with the inner cavity of the third purification cylinder 51 is formed in the middle of the fifth gas delivery end plate 52. The fifth gas delivery hole is communicated with the second purification treatment component 4 through a third gas delivery conduit 431. The sixth gas delivery end plate 53 is provided at the air outlet end of the third purification cylinder 51, and a sixth gas delivery hole communicating with the inner cavity of the third purification cylinder 51 is formed in the middle of the sixth gas delivery end plate 53. The sixth gas delivery hole is connected to the fourth gas delivery conduit 531. In this way, after the asphalt flue gas that has been deeply adsorbed and thermally catalyzed by the second purification treatment component 4 enters the third purification cylinder 51, the organic molecular sieve adsorbent in the organic molecular sieve adsorbent filling layer 511 adsorbs harmful organic matter in the remaining asphalt flue gas, while not adsorbing or adsorbing less CO2 and H2O generated by the reaction of the second purification treatment component 4, thereby achieving selective adsorption of the asphalt flue gas, so that the third purification treatment component 5 can better selectively adsorb the residual asphalt flue gas.

[0062] Furthermore, the material used to form the organic molecular sieve adsorbent filling layer 511 includes a second material, which includes a molecular sieve and an organic polymer film coated on the surface of the molecular sieve. In this way, the organic molecular sieve adsorbent filling layer 511 has a better selective adsorption effect. Specifically, the molecular sieve is a 4A molecular sieve with a silicon-aluminum ratio of 200%. The specific preparation process of the second material is as follows: First, select a 4A molecular sieve with a particle size of 3mm to 5mm and a silicon-aluminum ratio of 200%, add an appropriate amount of NaNO3 (analytical grade) solution, stir in a 75°C water bath for 4 hours, filter, and dry to activate the molecular sieve; then, take an appropriate amount of octadecyltrimethylammonium chloride, place it in a 75°C water bath and stir, and slowly add the activated molecular sieve while stirring in a ratio of 35:100 of organic reagent to molecular sieve, so that it is dispersed in the octadecyltrimethylammonium chloride. Stir in a 75°C water bath for 3.0 hours. After standing and stratification, take the upper layer solution, filter, dry, and grind to obtain the second material.

[0063] Furthermore, the third purification cartridge 51 is sealedly connected to the fifth gas transmission end plate 52; and / or, the third purification cartridge 51 is sealedly connected to the sixth gas transmission end plate 53; and / or, the material of the third purification cartridge 51 includes high borosilicate glass. The above features can be set selectively or simultaneously. As a preferred embodiment of the present invention, the above features are present simultaneously, which can make the third purification treatment component 5 more sealed, thereby improving the selective adsorption effect of asphalt fume. It is understandable that the present invention does not limit the specific method of sealing the third purification cartridge 51 and the fifth gas transmission end plate 52. For example, the third purification cartridge 51 and the fifth gas transmission end plate 52 are threadedly connected to achieve a sealed connection. Specifically, an internal thread is provided on the third purification cartridge 51, and an external thread is provided on the fifth gas transmission end plate 52. The internal thread and the external thread are screwed together to achieve a sealed connection between the third purification cartridge 51 and the fifth gas transmission end plate 52. It is understandable that, similar to the sealed connection between the third purification cartridge 51 and the fifth gas transmission end plate 52 , the present invention does not limit the specific manner of the sealed connection between the third purification cartridge 51 and the sixth gas transmission end plate 53 .

[0064] Furthermore, the third purification component 5 also includes a third threaded fastener 54, the two ends of which are respectively connected to the fifth gas transmission end plate 52 and the sixth gas transmission end plate 53, so that the fifth gas transmission end plate 52 and the sixth gas transmission end plate 53 are relatively fixed. This arrangement ensures that the fifth gas transmission end plate 52 and the sixth gas transmission end plate 53 are firmly fastened together, thereby improving the reliability of the third purification component 5. There is no restriction on the specific structure of the third threaded fastener 54, which can be a screw, a stainless steel column, etc. There is no restriction on the specific method of connecting the third threaded fastener 54 to the fifth gas transmission end plate 52 (or the sixth gas transmission end plate 53), which can be a welding connection or a threaded connection, etc. There is no restriction on the specific number of the third threaded fasteners 54. In the embodiment of the present invention, six third threaded fasteners 54 are provided, and the six third threaded fasteners 54 are evenly distributed at an angle of 60° along the circumference of the third purification cylinder 51.

[0065] Specifically, in the embodiment of the present invention, the fume extraction pump 2 is connected to the asphalt mixture mixing bin 1 through a fifth gas transmission conduit 21 .

[0066] In order to improve the sealing performance of the asphalt mixing plant flue gas purification system 100, the first gas delivery end plate 32 and the first gas delivery conduit 321 are sealed and connected by nuts and rubber gaskets, the second gas delivery end plate 33 and the second gas delivery conduit 331 are sealed and connected by nuts and rubber gaskets, the third gas delivery end plate 42 and the second gas delivery conduit 331 are sealed and connected by nuts and rubber gaskets, the fourth gas delivery end plate 43 and the third gas delivery conduit 431 are sealed and connected by nuts and rubber gaskets. The fifth gas delivery end plate 52 and the third gas delivery conduit 431 are sealed and connected by means of nuts fastening and rubber gaskets, the sixth gas delivery end plate 53 and the fourth gas delivery conduit 531 are sealed and connected by means of nuts fastening and rubber gaskets, the flue gas extraction pump 2 and the first gas delivery conduit 321 are sealed and connected by means of nuts fastening and rubber gaskets, and the flue gas extraction pump 2 and the fifth gas delivery conduit 21 are sealed and connected by means of nuts fastening and rubber gaskets.

[0067] Specifically, the first to fifth gas transmission conduits are all made of stainless steel, and the first to sixth gas transmission holes are all provided with fixed metal meshes.

[0068] use Figure 1 The flue gas purification treatment system of the asphalt mixing station shown in the figure treats the asphalt flue gas from the mixing silo of ordinary petroleum asphalt mixture and the mixing silo of SBS modified asphalt mixture respectively. The asphalt flue gas emitted from the mixing silo before and after the use of the purification treatment system is collected, and the particulate matter concentration, toluene concentration, xylene concentration, non-methane total hydrocarbon concentration and benzopyrene concentration in each asphalt flue gas are tested using instruments such as Laoying portable smoke automatic tester, high-precision electronic balance, gas chromatograph and high-performance liquid chromatograph. The test results are shown in Table 1.

[0069] Table 1 Measured results of various substances in asphalt flue gas before and after purification

[0070]

[0071]

[0072] Note: The standard limit refers to organized emissions.

[0073] As shown in Table 1, compared to ordinary petroleum asphalt mixtures, the emissions of light components such as toluene, xylene, and non-methane hydrocarbons in SBS modified asphalt mixtures were reduced, but particulate matter and benzopyrene increased by 17.7% and 20.3%, respectively. However, after using the purification measures in the examples, all detected components in both ordinary petroleum asphalt mixtures and SBS modified asphalt mixtures showed a significant reduction trend, with an average reduction of over 90%, both meeting the standard limits in the "Integrated Emission Standard of Air Pollutants" (GB16297) and the "Specifications for the Construction of Asphalt Mixing Plants" (DB34 / T3679). In particular, the emissions of toluene and xylene were already below the instrument detection limit, recorded as <0.0015. The results in Table 1 show that the asphalt mixing plant flue gas purification system of the examples can effectively treat harmful asphalt flue gas emitted by asphalt mixing plants and significantly reduce the environmental load during the preparation of hot mix asphalt mixtures.

[0074] The above description is only a preferred embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made by using the contents of the present invention description and drawings under the concept of the present invention, or direct / indirect application in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. An asphalt mixing plant flue gas purification system, characterized in that: It includes an asphalt mixture mixing bin, a fume extraction pump, a first purification treatment component, a second purification treatment component and a third purification treatment component which are connected in sequence; The fume extraction pump is used to extract the asphalt fume in the asphalt mixture mixing bin, so that the asphalt fume flows through the first purification treatment component, the second purification treatment component, and the third purification treatment component in sequence. The first purification treatment component is used to perform dust removal and drying treatment on the asphalt fume, the second purification treatment component is used to perform adsorption-thermocatalytic treatment on the asphalt fume, and the third purification treatment component is used to selectively adsorb the asphalt fume. The first purification component includes: The first purification cylinder has an air inlet end and an air outlet end opposite to each other, and a first air filter, a molecular sieve desiccant filling layer, and a second air filter are sequentially arranged in the inner cavity of the first purification cylinder from the air inlet end to the air outlet end. a first gas delivery end plate, provided at the gas inlet end of the first purification cylinder, and having a first gas delivery hole in communication with the inner cavity of the first purification cylinder formed in the middle of the first gas delivery end plate, the first gas delivery hole being in communication with the flue gas extraction pump via a first gas delivery conduit; and A second gas delivery end plate is provided at the gas outlet end of the first purification cylinder, and a second gas delivery hole is formed in the middle of the second gas delivery end plate, communicating with the inner cavity of the first purification cylinder. The second gas delivery hole is connected to the second purification treatment component through a second gas delivery conduit; The first purification cylinder is sealed to the first gas transmission end plate; and / or, The first purification cylinder is sealed to the second gas transmission end plate; and / or, The material of the first purification cylinder includes high borosilicate glass; The first purification component further includes a first threaded fastener, the two ends of the first threaded fastener being respectively connected to the first gas delivery end plate and the second gas delivery end plate, so that the first gas delivery end plate and the second gas delivery end plate are relatively fixed; The second purification treatment component includes: The second purification cylinder has an air inlet end and an air outlet end that are oppositely arranged. An oil inlet and an oil outlet are formed on the side of the second purification cylinder. An oil guide pipe for transmitting heat transfer oil is provided in the second purification cylinder. One end of the oil guide pipe enters the second purification cylinder through the oil inlet, and the other end exits the second purification cylinder through the oil outlet. A molecular sieve carrier filling layer is provided in an area of the inner cavity of the second purification cylinder surrounding the oil guide pipe. a third gas delivery end plate, provided at the gas inlet end of the second purification cylinder, and having a third gas delivery hole formed in the middle portion thereof, communicating with the inner cavity of the second purification cylinder, and the third gas delivery hole being communicated with the first purification cylinder via a second gas delivery conduit; and a fourth gas delivery end plate, disposed at the gas outlet end of the second purification cylinder, and having a fourth gas delivery hole formed in the middle portion thereof, communicating with the inner cavity of the second purification cylinder, the fourth gas delivery hole being in communication with the third purification treatment assembly via a third gas delivery conduit; The material used to form the molecular sieve support filling layer includes a first material, wherein the first material includes a molecular sieve support and an iron-manganese-cerium ternary composite oxide catalyst supported on the molecular sieve support; The oil guide pipe is spirally extended from the air inlet end to the air outlet end of the second purification cylinder; The air inlet and outlet ends of the oil guide pipe are connected to the heat transfer oil channel of the asphalt mixture mixing bin to form a circulation passage; The second purification cylinder is sealed to the third gas transmission end plate; and / or, The second purification cylinder is sealed and connected to the fourth gas transmission end plate; and / or, The material of the second purification cartridge includes quartz glass; and / or, The second purification component further includes a second threaded fastener, the two ends of which are respectively connected to the third gas delivery end plate and the fourth gas delivery end plate, so that the third gas delivery end plate and the fourth gas delivery end plate are relatively fixed. The third purification treatment component includes: The third purification cartridge has an air inlet end and an air outlet end that are relatively arranged. An organic molecular sieve adsorbent filling layer is provided in the inner cavity of the third purification cartridge. The material of the organic molecular sieve adsorbent filling layer includes a second material, and the second material includes a molecular sieve and an organic polymer film coated on the surface of the molecular sieve.

2. The asphalt mixing plant flue gas purification system according to claim 1, characterized in that: The third purification treatment component further includes: a fifth gas delivery end plate, disposed at the gas inlet end of the third purification cylinder, and having a fifth gas delivery hole formed in the middle portion thereof, communicating with the inner cavity of the third purification cylinder, the fifth gas delivery hole being in communication with the second purification treatment assembly via a third gas delivery conduit; and The sixth gas delivery end plate is provided at the gas outlet end of the third purification cylinder, and a sixth gas delivery hole communicating with the inner cavity of the third purification cylinder is formed in the middle of the sixth gas delivery end plate, and the sixth gas delivery hole is connected with the fourth gas delivery conduit.

3. The asphalt mixing plant flue gas purification system according to claim 2, characterized in that: The third purification cylinder is sealed and connected to the fifth gas transmission end plate; and / or, The third purification cylinder is sealed and connected to the sixth gas transmission end plate; and / or, The material of the third purification cartridge includes borosilicate glass; and / or, The third purification component further includes a third threaded fastener, the two ends of which are respectively connected to the fifth gas delivery end plate and the sixth gas delivery end plate, so that the fifth gas delivery end plate and the sixth gas delivery end plate are relatively fixed.

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