Recycled concrete micro-powder preparation system with modified carbon sequestration function

Abstract

The invention relates to the technical field of utilization of building solid waste recycled concrete, and discloses a recycled concrete micro-powder preparation system with a modified carbon sequestration function. Comprising a first induced draft fan, a first cloth bag dust collector, a cyclone dust collector, a fine powder concentrator, a first bucket elevator, a discharging stop valve, an air volume adjusting valve, a cement kiln tail exhaust fan, a second bucket elevator, a V-shaped powder concentrator, a surge bin, a roller press, a set cement particle conveyor, an outer circulation vertical mill and an air locking valve, and further comprises a solid modification unit and a set cement stripping unit. According to the invention, the carbon dioxide emission of a cement kiln is directly reduced, a contribution is made for relieving the greenhouse effect, the density and strength of the recycled concrete micro powder are improved, the recycled concrete micro powder can be used as a high-quality admixture for producing low-carbon building materials such as cement mortar admixtures, baking-free bricks, water permeable bricks and the like, the application range of the recycled concrete micro powder is widened, and the recycled concrete micro powder has a wide application prospect. The market competitiveness is improved, and the sustainable development of the building industry is promoted.

Description

Technical Field

[0001] This invention relates to the field of recycled concrete utilization technology from construction solid waste, and in particular to a recycled concrete micro powder preparation system with self-modified carbon sequestration function. Background Technology

[0002] With the development of urbanization in China, a large amount of construction solid waste has been generated. How to effectively treat this construction solid waste and realize its resource utilization has become an important issue facing the construction industry. Recycled concrete powder, as an important way to utilize construction solid waste resources, has received widespread attention.

[0003] From an environmental perspective, cement production emits a large amount of carbon dioxide, which has a serious impact on global climate change. According to relevant research, the cement industry accounts for approximately 7%-8% of global industrial carbon dioxide emissions. Existing cement kiln tail emission systems treat the waste gas from the production process by directly venting it into the atmosphere (the waste gas contains approximately 20% CO2 and has a temperature of 80-180℃), which not only wastes the waste heat resources but also contributes to greenhouse gas pollution.

[0004] CO2 can react with calcium hydroxide (Ca(OH)2) or silicate minerals in concrete to form stable calcium carbonate (CaCO3) or calcium silicate hydrate (CSH), thus permanently sequestering CO2 in mineral form. This carbon fixation reaction not only fixes CO2 but also optimizes the physical properties of the recycled micro-powder: the reaction products fill micropores, increasing density by approximately 5%; the formation of carbonates and silicates strengthens the structure of the micro-powder products, significantly improving crushing performance.

[0005] Currently, although there are some studies on the modification of recycled concrete powder, most of them use methods such as adding chemical admixtures. These methods are not only costly, but some admixtures may also cause secondary pollution to the environment. At the same time, in terms of carbon sequestration, existing technologies are either inefficient and cannot fully utilize carbon dioxide resources, or the equipment is complex and the investment cost is huge, making it difficult to apply widely in actual production.

[0006] On the other hand, the traditional preparation process uses a crusher to finely pulverize construction solid waste concrete, resulting in recycled concrete powder with a relatively coarse fineness and large fluctuations in its composition. The powder contains a low content of cement stone powder that can be used for carbon fixation, namely, a high proportion of calcium carbonate (CaCO3) and silicon dioxide (SiO2), while a low proportion of calcium silicate hydrate (CSH) and calcium hydroxide (CH), which can chemically react with CO2. Therefore, it is not very effective for direct carbon fixation.

[0007] In summary, existing technologies for preparing recycled concrete powder have many shortcomings in terms of improving powder performance, utilizing carbon dioxide for carbon sequestration, and environmentally friendly treatment. An innovative technology is urgently needed to solve these problems. Summary of the Invention

[0008] (a) Technical problems to be solved

[0009] To address the shortcomings of existing technologies, this invention provides a recycled concrete micropowder preparation system with built-in modified carbon fixation function, mainly targeting the problems of poor micropowder performance, ineffective utilization of carbon dioxide, and imperfect environmental treatment in the preparation process of recycled concrete micropowder in existing technologies.

[0010] (II) Technical Solution

[0011] To achieve the above objectives, the present invention adopts the following technical solution:

[0012] A recycled concrete powder preparation system with built-in modification and carbon fixation function includes a first induced draft fan, a bag filter dust collector, a cyclone dust collector, a fine classifier, a first bucket elevator, a discharge stop valve, an air volume regulating valve, a cement kiln tail exhaust fan, a second bucket elevator, a V-type classifier, a buffer silo, a roller press, a cement stone particle conveyor, an external circulation vertical mill, and an airlock valve. It also includes a solid modification unit and a cement stone stripping unit. The outlet of the bag filter dust collector is connected to the first induced draft fan, and the outlet of the cement stone particle conveyor is connected to the inlet of the second bucket elevator.

[0013] The solid modification unit includes a suspension reactor, a lock valve, a second bag dust collector, and a second induced draft fan. The suspension reactor includes a reactor body, a discharge port, an air inlet, two rotary feeders, a nozzle, a cyclone separator, an air outlet, and a storage tank.

[0014] The cement stone stripping unit includes a vertical shaft impact crusher, a vibrating screen, a third bucket elevator, and a storage bin. The vibrating screen is equipped with three layers of screen mesh.

[0015] Furthermore, the reactor body has a hollow cavity structure. The discharge port and air inlet are located below the reactor body. The nozzle is located in the middle of the reactor body. The cyclone is located at the top of the reactor body. The two rotary feeders are respectively located at the bottom of the cyclone and the channel connecting the reactor body and the storage tank and the main body. The air inlet of the suspension reactor is connected to the air outlet pipe of the cement kiln tail exhaust fan, and the air outlet is connected to the second bag dust collector. The second bag dust collector is connected to the second induced draft fan. The discharge port of the second bag dust collector is connected to the inlet of the storage tank.

[0016] Based on the aforementioned scheme, the feed inlet of the vertical shaft impact crusher is connected to the discharge outlet of the uppermost screen of the vibrating screen, the discharge outlet of the vertical shaft impact crusher is connected to the inlet of the third bucket elevator, the outlet of the third bucket elevator is connected to the feed inlet of the vibrating screen, and the discharge outlets of the other two screens of the vibrating screen and the discharge outlet of the vibrating screen are respectively connected to the storage silo.

[0017] As a further embodiment of the present invention, the roller press includes a frame, a hydraulic loading system, a roller system and a feeding device, and the external circulation vertical mill includes a feed pipe, a housing, grinding rollers, a grinding disc, a frame, a hydraulic loading system, a drive system and a scraper.

[0018] Furthermore, the V-type classifier is a type of static classifier, including a feed inlet, an air inlet, a dispersing plate, a coarse powder outlet, a shell, and an air outlet. The V-type classifier is a type of static classifier, including a feed inlet, an air inlet, a dispersing plate, a coarse powder outlet, a shell, and an air outlet. The air inlet is equipped with a fresh air inlet, and the fresh air inlet pipe is equipped with an air volume regulating valve.

[0019] Based on the aforementioned scheme, the feed inlet of the feeding device in the roller press and the feed pipe of the external circulation vertical mill are connected to the discharge outlet of the buffer silo. The discharge outlets of the roller press and the external circulation vertical mill are connected to the feed inlet of the V-type classifier via the first bucket elevator. The coarse powder discharge outlet of the V-type classifier is connected to the feed inlet of the buffer silo, and the air outlet of the V-type classifier is connected to the feed inlet of the fine classifier. The air inlet of the V-type classifier is connected to the exhaust pipe of the cement kiln tail exhaust fan. The coarse powder discharge outlet of the fine classifier is connected to the feed inlet of the buffer silo. The air outlet of the fine classifier is connected to the air inlet of the first bag dust collector. The discharge outlet of the second bucket elevator is connected to the feed inlet of the V-type classifier and the feed inlet of the buffer silo.

[0020] As a further embodiment of the present invention, the external circulation vertical mill and the roller press are used as the main grinding equipment, and one or both of them can be used alone.

[0021] Furthermore, each of the aforementioned air ducts is equipped with an air volume regulating valve.

[0022] The beneficial effects of this invention are as follows:

[0023] 1. This invention extracts waste gas from the exhaust duct of a cement kiln tail exhaust fan for carbon fixation through the modification of recycled concrete micropowder, directly reducing carbon dioxide emissions from the cement kiln and contributing to mitigating the greenhouse effect. This technology successfully utilizes the grinding of construction solid waste to achieve chemical carbon fixation of carbon dioxide in the cement kiln tail exhaust gas. Theoretically, each ton of recycled micropowder with a specific surface area of ​​300 m² / kg can reduce carbon dioxide emissions by 100-150 kg. my country's cement industry is large-scale, and cement kilns emit a large amount of carbon dioxide every year. If this system is fully utilized, the carbon reduction effect will be considerable over the long term.

[0024] 2. In the resource utilization of construction solid waste, the modified recycled concrete powder improves the density and strength, and can be used as a high-quality admixture in the production of low-carbon building materials such as cement mortar admixtures, non-fired bricks, and permeable bricks. This broadens the application range of recycled concrete powder, enhances its market competitiveness, and promotes the sustainable development of the construction industry.

[0025] 3. From an economic perspective, this invention allows enterprises to gain economic benefits by selling high-performance recycled micro-powder. Construction waste, originally treated as solid waste, is transformed into valuable products, reducing the enterprise's solid waste treatment costs. Simultaneously, utilizing kiln tail gas—a previously wasted resource—reduces additional costs associated with waste gas treatment, achieving resource recycling and improving the enterprise's economic efficiency.

[0026] 4. This invention achieves multiple goals: "carbon reduction in cement kiln emissions + carbon fixation with recycled micro powder + efficiency improvement in high-value utilization of construction solid waste + economic benefits from the sale of recycled micro powder," providing strong support for the green transformation of the building materials industry. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of a recycled concrete micropowder preparation system with self-modified carbon fixation function according to Embodiment 1 of the present invention.

[0028] Figure 2 This is a schematic diagram of the roller press according to Embodiment 1 of the present invention;

[0029] Figure 3 This is a schematic diagram of the external circulation vertical mill structure of Embodiment 1 proposed in this invention;

[0030] Figure 4 This is a schematic diagram of the V-type air classifier according to Embodiment 1 of the present invention;

[0031] Figure 5 This is a schematic diagram of the fine air classifier according to Embodiment 1 of the present invention;

[0032] Figure 6 This is a schematic diagram of the suspension reactor of Embodiment 1 proposed in this invention;

[0033] Figure 7 This is a schematic diagram of a recycled concrete micropowder preparation system with self-modified carbon fixation function according to Embodiment 2 of the present invention;

[0034] Figure 8 This is a schematic diagram of a recycled concrete micropowder preparation system with self-modified carbon fixation function, as proposed in Embodiment 3 of the present invention.

[0035] In the diagram: 1. First induced draft fan; 201. Bag dust collector one; 202. Bag dust collector two; 3. Cyclone dust collector; 4. Fine powder classifier; 401. Air inlet; 402. Coarse powder outlet; 403. Semi-coarse powder outlet; 404. Shell; 405. Rotary drum; 406. Air outlet; 407. Drive unit; 5. First bucket elevator; 601-606. Discharge stop valve; 701 -707, Air volume regulating valve; 8, Cement kiln tail exhaust fan; 9, Second bucket elevator; 10, V-type air classifier; 1001, Feed inlet; 1002, Air inlet; 1002, Dispersing plate; 1004, Coarse powder outlet; 1005, Shell; 1005, Air outlet; 11, Buffer silo; 12, Roller press; 1201, Frame; 1201, Hydraulic loading system; 1203, Roller system; 1204, Feeding device; 13, Cement stone particle conveyor; 14, External circulation vertical mill; 1401, Feed pipe; 1402, Shell; 1403, Grinding roller; 1404, Grinding disc; 1405, Frame; 1406, Hydraulic loading system; 1407, Drive system; 1408, Scraper; 15, Suspension reactor; 1501, Discharge port; 1502, Air inlet; 15 03. Rotary feeder; 1504. Nozzle; 1505. Cyclone separator; 1506. Air outlet; 1507. Reactor body; 1508. Storage tank; 1601-1606. Airlock valve; 17. Second induced draft fan; 18. Cement stone powder storage silo; 19. Vertical shaft impact crusher; 20. Vibrating screen; 21. Third bucket elevator; S1-S3. Storage bin; 22. Large bag dust collector. Detailed Implementation

[0036] 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. It should be noted that, unless otherwise expressly specified and limited, the terms "installation", "connection", and "setting" should be interpreted broadly. For those skilled in the art, the specific meaning of the above terms in this patent can be understood according to the specific circumstances.

[0037] Example 1

[0038] Reference Figure 1A recycled concrete micro powder preparation system with self-modification and carbon fixation function includes a first induced draft fan 1, a bag dust collector 201, a cyclone dust collector 3, a fine powder classifier 4, a first bucket elevator 5, a discharge stop valve 601-606, an air volume regulating valve 701-705, a cement kiln tail exhaust fan 8, a second bucket elevator 9, a V-type powder classifier 10, a buffer silo 11, a roller press 12, a cement stone particle conveyor 13, an external circulation vertical mill 14, and airlock valves 1601-1604. It also includes a solid modification unit and a cement stone stripping unit. The air outlet of the bag dust collector 201 is connected to the first induced draft fan 1, and the outlet of the cement stone particle conveyor 13 is connected to the feed inlet of the second bucket elevator 9.

[0039] In this invention, the solid-state modification unit includes a suspension reactor 15, airlock valves 1605-1606, a bag filter 202, and a second induced draft fan 17, as shown in the reference. Figure 6 The suspension reactor 15 includes a reactor body 1507, a discharge port 1501, an air inlet 1502, two rotary feeders 1503, a nozzle 1504, a cyclone separator 1505, an air outlet 1506, and a storage tank 1508. The reactor body 1507 has a hollow internal structure. The discharge port 1501 and the air inlet 1502 are located below the reactor body 1507. The nozzle 1504 is located in the middle of the reactor body 1507, and the cyclone separator 1505 is located within the reactor body 1507. At the top, two rotary feeders 1503 are respectively set on the lower part of the cyclone 1505 and the channel connecting the reactor body 1507 and the storage tank 1508 and the main body 1507. The air inlet 1502 of the suspension reactor 15 is connected to the air outlet pipe of the cement kiln tail exhaust fan 8, and the air outlet 1506 is connected to the second bag dust collector 202. The second bag dust collector 202 is connected to the second induced draft fan 17. The discharge port of the second bag dust collector 202 is connected to the inlet of the storage tank 1508.

[0040] In this invention, the cement stone stripping unit includes a vertical shaft impact crusher 19, a vibrating screen 20, a third bucket elevator 21, and storage bins S1-S3. The vibrating screen 20 is equipped with three layers of screens, with apertures of 20-10-5mm from top to bottom. The feed inlet of the vertical shaft impact crusher 19 is connected to the discharge outlet of the uppermost screen of the vibrating screen 20, the discharge outlet of the vertical shaft impact crusher 19 is connected to the inlet of the third bucket elevator 21, the outlet of the third bucket elevator 21 is connected to the feed inlet of the vibrating screen 20, and the discharge outlets of the other two layers of screens of the vibrating screen 20 and the discharge outlet of the vibrating screen 20 are respectively connected to the storage bins S1-S3.

[0041] Reference Figure 2The roller press 12 includes a frame 1201, a hydraulic loading system 1202, a roller system 1203, and a feeding device 1204. The material is fed into the meshing area of ​​a pair of extrusion rollers in the roller system 1203 located in the frame 1201 through the feeding device 1204. After being extruded and crushed into powder, the material is discharged from the roller press. The hydraulic loading system 1202 outputs the extrusion force of the extrusion rollers through a hydraulic cylinder.

[0042] Reference Figure 3 The external circulation vertical mill 14 includes a feed pipe 1401, a housing 1402, a grinding roller 1403, a grinding disc 1404, a frame 1405, a hydraulic loading system 1406, a drive system 1407, and a scraper 1408. The hydraulic loading system 1404 applies a loading force to the grinding roller 1403 through a hydraulic cylinder. The material enters the upper part of the grinding disc 1404 through the feed pipe 1401. The drive system 1407 is a combination of a motor and a reducer, which drives the grinding disc 1404 to rotate. Centrifugal force throws the material on the grinding disc into the grinding area of ​​the grinding roller 1403 for grinding. After being thrown out of the grinding disc 1404, the ground material is scraped out of the vertical mill discharge port by the scraper 1408 at the bottom of the grinding disc. There is no need for ventilation inside the vertical mill housing 1402 to lift the powder.

[0043] Reference Figure 4 The V-type classifier 10 is a type of static classifier, including a feed inlet 1001, an air inlet 1002, a dispersing plate 1003, a coarse powder outlet 1004, a shell 1005, and an air outlet 1006. The air inlet 1002 is equipped with a fresh air inlet, and the fresh air inlet pipe is equipped with an air volume regulating valve 701 to adjust the proportion of fresh air, so as to achieve the goal of stabilizing the internal air temperature of the grinding system and adjusting the temperature of the exhaust gas entering the classifier. After the material enters the V-classifier through the feed inlet 1001, it falls on the dispersing plate to form a splashing material curtain effect. The kiln tail exhaust gas enters the V-classifier through the air inlet 1002 and carries the fine particles in the material curtain out of the air outlet 1006. The coarse particles are discharged from the coarse powder outlet 1004 under the action of gravity.

[0044] Reference Figure 5 The fine powder classifier 4 includes an air inlet 401, a coarse powder outlet 402, a semi-coarse powder outlet 403, a shell 404, a rotating drum 405, an air outlet 406, and a drive device 407. The powder to be classified is carried into the powder classifier by air through the air inlet 401. After passing through the rotating drum 405 driven by the drive device 407, the coarse powder and semi-coarse powder are discharged from the coarse powder outlet 402 and the semi-coarse powder outlet 403, respectively. The finished fine powder is discharged from the air outlet 406. By adjusting the air volume and the rotating drum speed of the fine powder classifier, finished products of different fineness can be obtained.

[0045] The feed inlet of the feeding device 1204 in the roller press 12 and the feed pipe 1401 of the external circulation vertical mill 14 are connected to the discharge outlet of the buffer bin 11. The discharge outlets of the roller press 12 and the external circulation vertical mill 14 are connected to the feed inlet 1001 of the V-type classifier 10 through the first bucket elevator 5. The coarse powder discharge outlet 1004 of the V-type classifier 10 is connected to the feed inlet of the buffer bin 11, and the air outlet 1006 of the V-type classifier 10 is connected to the fine powder discharge outlet. The feed inlet of the powder mill 4 is connected to the air inlet 1002 of the V-type classifier 10, which is connected to the exhaust pipe of the cement kiln tail exhaust fan 8. The coarse powder outlet 402 of the fine classifier 4 is connected to the feed inlet of the buffer silo 11. The air outlet 406 of the fine classifier 4 is connected to the air inlet of the bag dust collector 201. The discharge outlet of the second bucket elevator 9 is connected to the feed inlet 1001 of the V-type classifier 10 and the feed inlet of the buffer silo 11.

[0046] The process flow of this system is as follows:

[0047] First, concrete blocks from the waste concrete storage silo have been pre-crushed and iron removed, with a particle size of less than 100mm. They are then fed into the cement stone stripping unit and fed into the vibrating screen 20 via the third bucket elevator 21. Inside the vibrating screen, the particles are graded. Particles larger than 20mm are fed into the vertical shaft impact crusher 19 for crushing. Particles larger than 10mm and smaller than 20mm are fed into the S1 bin, particles larger than 5mm and smaller than 10mm are fed into the S3 bin, and particles smaller than 5mm are fed into the S2 bin. Cement stone particles are easier to strip than aggregate particles, and are concentrated in the range of larger than 5mm and smaller than 10mm, so they are stored in the S3 bin.

[0048] Secondly, the cement stone particles in the S3 silo are fed into the second bucket elevator 9 via the conveyor 13, and then lifted by the second bucket elevator 9 to the feed inlet 1001 of the V-type classifier 10. The coarse material after the initial selection by the V-type classifier 10 enters the buffer silo 11. The coarse material is then sent to the roller press 12 or the external circulation vertical mill 14 for grinding, and then conveyed by the first bucket elevator 5 to the feed inlet 1001 of the V-type classifier 10 for further classification. The fine powder from the V-type classifier 10 enters the fine classifier 4 for further classification. The finished fine powder with qualified fineness after being classified by the fine classifier 4 enters the cyclone dust collector 3 for initial collection, and then enters the bag dust collector for complete collection. The finished concrete micro powder is stored and collected in the storage silo 18. The ventilation throughout the process is drawn from the exhaust pipe of the cement kiln tail exhaust fan 8 by the first induced draft fan 1.

[0049] Finally, the shut-off valve 606 is opened, and the cement stone powder in the storage tank 18 is transported into the carbon fixation modification system to continue the carbon fixation reaction. The second induced draft fan 17 draws the kiln tail exhaust gas from the exhaust pipe of the kiln tail exhaust fan 8 from bottom to top and enters the suspension reactor 15 through the air inlet 1501. The nozzle 1505 sprays clean water into the suspension reactor 15, and the amount of water sprayed is adjusted according to the weight of the carbon fixation powder added per hour. The carbon fixation modified powder is stored in the storage tank 1508 beforehand, and is then transported by the rotary valve. The material is evenly fed into the suspension reactor in the material zone 1503, mixed and reacted with the kiln tail exhaust gas, and carried into the cyclone 1505 for gas-solid separation. The exhaust gas enters the dust collector 202 through the outlet 1506. After the micro powder particles settle in the cyclone, they are returned to the suspension reactor 15 through the rotary feeder 1503 for recycling reaction. Finally, the regenerated micro powder that has been modified by carbon fixation is discharged from the suspension reactor 15 through the outlet 1501 due to its heavy weight, thus obtaining the regenerated micro powder after carbon fixation modification.

[0050] In this invention, the feeding object of the second bucket elevator 9 can be adjusted according to the moisture content of the raw material concrete blocks. If the moisture content of the raw material is high, the shut-off valve 602 is opened and the shut-off valve 603 is closed, and the raw material is first fed into the V-type classifier 10 to enhance drying. If the moisture content of the raw material is low, the shut-off valve 602 is closed and the shut-off valve 603 is opened, and the raw material is first fed into the buffer chamber 11, which helps to reduce the powder concentration of the V-type classifier 10 and improve the powder selection efficiency.

[0051] In this invention, different grinding main equipment can be selected and switched according to the particle size and moisture content of the concrete raw materials. The external circulation vertical mill 14 is suitable for the working conditions of large feed particles and high moisture content, while the roller press 12 is suitable for the working conditions of small feed particles and low moisture content. The roller press 12 or the external circulation vertical mill 14 can be switched to work by opening or closing the shut-off valves 604 and 605.

[0052] In this invention, the first bucket elevator 5 is provided with an external discharge port. The discharge volume of the first bucket elevator 5 is controlled by opening the shut-off valve 601, which facilitates the discharge of materials inside the system during shutdown or emergency.

[0053] In this invention, each air duct is equipped with an air volume regulating valve 702-704, which is used to adjust the proportion of exhaust gas directly discharged into the atmosphere by the cement kiln tail exhaust fan 9, the air volume of the roller press 12, the external circulation vertical mill 14, the V-type air classifier 10 and the fine air classifier 4, and the air volume used by the enhanced carbon fixation and modification system.

[0054] Example 2

[0055] Reference Figure 7Embodiment 2 of the present invention provides a recycled concrete micro powder preparation system with built-in modified carbon fixation function. The difference between this embodiment and Embodiment 1 is that a large bag dust collector 22 is set to replace the combination of cyclone dust collector 3 and bag dust collector 201, which makes the layout simpler. In addition, only the roller press 12 is used as the main grinding equipment, and the external circulation vertical mill 14 is eliminated. This system is more suitable for occasions where the properties of raw materials can be controlled, and the initial investment of the system is reduced.

[0056] Example 3

[0057] Reference Figure 8 Embodiment 3 of the present invention provides a recycled concrete micro powder preparation system with self-fixation and carbon modification function. The difference between this embodiment and Embodiment 1 is that the roller press 12 is eliminated and an external circulation vertical mill 14 is used as the main equipment for preparing recycled micro powder. This is suitable for situations where there are many large particles and high moisture content in the raw materials, thus reducing the initial investment of the system. In addition, a circulating fan 17 is set at the outlet of the cyclone dust collector 3. This fan sends a portion of the residual air from the outlet of the cyclone dust collector 3 back to the air inlet of the V-type classifier 10, which is beneficial to the energy saving of the system. At the same time, the first induced draft fan 1 is used as an exhaust fan, which can reduce the specifications and investment cost of the first induced draft fan 1.

[0058] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A recycled concrete micropowder preparation system with built-in modified carbon fixation function, comprising a first induced draft fan, a bag filter dust collector, a cyclone dust collector, a fine classifier, a first bucket elevator, a discharge stop valve, an air volume regulating valve, a cement kiln tail exhaust fan, a second bucket elevator, a V-type classifier, a buffer silo, a roller press, a cement stone particle conveyor, an external circulation vertical mill, and an airlock valve, characterized in that... It also includes a solid modification unit and a cement stone stripping unit. The air outlet of the bag dust collector is connected to the first induced draft fan, and the outlet of the cement stone particle conveyor is connected to the feed inlet of the second bucket elevator. The solid modification unit includes a suspension reactor, a lock valve, a second bag dust collector, and a second induced draft fan. The suspension reactor includes a reactor body, a discharge port, an air inlet, two rotary feeders, a nozzle, a cyclone separator, an air outlet, and a storage tank. The cement stone stripping unit includes a vertical shaft impact crusher, a vibrating screen, a third bucket elevator, and a storage bin. The vibrating screen is equipped with three layers of screen mesh.

2. The recycled concrete micropowder preparation system with self-modified carbon fixation function according to claim 1, characterized in that, The reactor body has a hollow internal structure. The discharge port and air inlet are located at the bottom of the reactor body. The nozzle is located in the middle of the reactor body. The cyclone is located at the top of the reactor body. The two rotary feeders are respectively located at the bottom of the cyclone and the channel connecting to the reactor body, and at the channel connecting the storage tank and the reactor body. The air inlet of the suspension reactor is connected to the air outlet pipe of the cement kiln tail exhaust fan, and the air outlet is connected to the second bag filter dust collector. The second bag filter dust collector is connected to the second induced draft fan. The discharge port of the second bag filter dust collector is connected to the inlet of the storage tank.

3. The recycled concrete micropowder preparation system with self-modified carbon fixation function according to claim 2, characterized in that, The feed inlet of the vertical shaft impact crusher is connected to the discharge outlet of the uppermost screen of the vibrating screen. The discharge outlet of the vertical shaft impact crusher is connected to the inlet of the third bucket elevator. The outlet of the third bucket elevator is connected to the feed inlet of the vibrating screen. The discharge outlets of the other two screens of the vibrating screen and the discharge outlet of the vibrating screen are respectively connected to the storage bin.

4. The recycled concrete micropowder preparation system with self-modified carbon fixation function according to claim 1, characterized in that, The roller press includes a frame, a hydraulic loading system, a roller system, and a feeding device. The external circulation vertical mill includes a feed pipe, a housing, grinding rollers, a grinding disc, a frame, a hydraulic loading system, a drive system, and a scraper.

5. The recycled concrete micropowder preparation system with self-modified carbon fixation function according to claim 4, characterized in that, The V-type air classifier is a type of static air classifier, including a feed inlet, an air inlet, a dispersing plate, a coarse powder outlet, a shell, and an air outlet. The air inlet is equipped with a fresh air inlet, and the fresh air inlet pipe is equipped with an air volume regulating valve.

6. The recycled concrete micropowder preparation system with self-modified carbon fixation function according to claim 5, characterized in that, The feed inlet of the roller press and the feed pipe of the external circulation vertical mill are connected to the discharge outlet of the buffer silo. The discharge outlet of the roller press and the external circulation vertical mill are connected to the feed inlet of the V-type classifier through the first bucket elevator. The coarse powder discharge outlet of the V-type classifier is connected to the feed inlet of the buffer silo, and the air outlet of the V-type classifier is connected to the feed inlet of the fine classifier. The air inlet of the V-type classifier is connected to the exhaust pipe of the cement kiln tail exhaust fan. The coarse powder discharge outlet of the fine classifier is connected to the feed inlet of the buffer silo. The air outlet of the fine classifier is connected to the air inlet of the first bag dust collector. The discharge outlet of the second bucket elevator is connected to the feed inlet of the V-type classifier and the feed inlet of the buffer silo.

7. The recycled concrete micropowder preparation system with self-modified carbon fixation function according to claim 1, characterized in that, The external circulation vertical mill and roller press are used as the main grinding equipment, and one or both of them can be used alone.

8. The recycled concrete micropowder preparation system with self-modified carbon fixation function according to claim 1, characterized in that, Each of the air ducts is equipped with an air volume regulating valve.

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