A hierarchical flexible heating RAP material regeneration system and a matching flue gas purification device

Abstract

This invention relates to the field of RAP (Rich Acrylic Acid) material technology, specifically a graded flexible heating RAP material regeneration system. The system includes a main RAP silo and a material regeneration system composed of a pretreatment and grading module, a flexible heating module, a regenerator addition module, and a mixing and discharging module. This graded flexible heating RAP material regeneration system and its supporting flue gas purification device grade materials according to particle size and asphalt aging degree, and treats materials differently based on their characteristics. This effectively improves the targeting of RAP material regeneration and the activation effect of aged asphalt. By employing a six-chamber independent and multi-heat-source flexible heating process, specific heating methods are matched to different materials, avoiding overheating and aging of fine aggregates and insufficient heating of coarse aggregates, significantly reducing the secondary aging rate of asphalt. A flue gas waste heat recovery system is constructed, greatly improving energy utilization. Furthermore, through cyclone dust removal, condensation oil removal, bag filter dust removal, and electrostatic precipitator tar treatment, asphalt fumes, dust, and harmful substances are effectively removed.

Description

Technical Field

[0001] This invention relates to the field of RAP material technology, specifically to a graded flexible heating RAP material regeneration system and a matching flue gas purification device. Background Technology

[0002] RAP material, or recycled asphalt pavement material, is the old asphalt mixture obtained after milling, crushing, and screening during the maintenance, reconstruction, and expansion of asphalt pavement. It is mainly composed of aged asphalt mastic, natural aggregates, and mineral powder, and is the solid recycled resource with the largest output and highest utilization rate in road engineering.

[0003] A search revealed a mobile RAP aggregate recycling system and method disclosed in Chinese Patent Publication No. CN118385017A. This RAP aggregate recycling system achieves crushing and grading screening of RAP waste material through continuous and systematic process flow. The related conveying devices, crushing devices, screening devices, and mobile chassis devices are interconnected to form an efficient and stable production system required for the aggregate recycling process, thereby improving screening efficiency and significantly enhancing screening accuracy.

[0004] However, this mobile RAP aggregate recycling system lacks temperature-controlled heating of the RAP aggregate and activation treatment with recycling agents, thus failing to effectively activate and soften aged asphalt in the RAP aggregate. Furthermore, it lacks waste heat recovery and flue gas purification effects. Therefore, based on these technical shortcomings, a staged flexible heating RAP aggregate recycling system and its supporting flue gas purification device are proposed. Summary of the Invention

[0005] (a) Technical problems to be solved

[0006] To address the shortcomings of existing technologies, this invention provides a graded flexible heating RAP material recycling system and a matching flue gas purification device. It has the advantages of graded flexible heating, tiered waste heat recovery, and efficient flue gas purification, solving the problems of existing RAP aggregate recycling systems that cannot effectively activate and soften aged asphalt and that require further improvement in flue gas waste heat treatment.

[0007] (II) Technical Solution

[0008] To achieve the aforementioned goals of graded flexible heating, tiered waste heat recovery, and efficient flue gas purification, this invention provides the following technical solution: a graded flexible heating RAP material regeneration system, including a RAP main silo, and a material regeneration system composed of a pretreatment and grading module, a flexible heating module, a regenerator addition module, and a mixing and discharging module.

[0009] Preferably, a receiving hopper is fixedly installed at the bottom of the RAP main silo, and the RAP main silo and the receiving hopper are connected by a hydraulic gate. The pretreatment grading module includes a vibrating feeder located below the receiving hopper. A first belt conveyor is provided on one side of the vibrating feeder. An electromagnetic separator is suspended on the top of the first belt conveyor. A crusher is provided on the side of the first belt conveyor away from the vibrating feeder. The top of the crusher is connected to the first belt conveyor through the receiving hopper.

[0010] Preferably, one side of the crusher is set as the discharge port, and an elevator is fixedly installed at the discharge port. An air-separating separator is fixedly installed on one side of the top of the elevator. A vibrating chamber is set on one side of the air-separating separator. Several layers of vibrating screens are movably installed inside the vibrating chamber. The screen aperture of the layers of vibrating screens decreases from top to bottom. A discharge port is opened on the side of each layer of vibrating screen that contacts the inner wall of the vibrating chamber. A second belt conveyor is set at each discharge port. A sorting robot equipped with a vision camera is set on the outside of the second belt conveyor.

[0011] Preferably, the flexible heating module includes a storage bin disposed on the side of the second belt conveyor away from the discharge port, a powder metering instrument fixedly installed at the bottom of the storage bin, a conveyor unit disposed below the storage bin, and a heating chamber fixedly disposed on the outside of the conveyor unit.

[0012] The conveyor system is composed of a first scraper conveyor for conveying lightly aged coarse aggregate, a second scraper conveyor for conveying moderately aged coarse aggregate, a third scraper conveyor for conveying heavily aged coarse aggregate, a vibrating conveyor for conveying medium aggregate, and a screw conveyor for conveying fine aggregate and mineral powder.

[0013] Preferably, the heating chamber is divided into a first heating chamber for heating lightly aged coarse aggregate, a second heating chamber for heating moderately aged coarse aggregate, a third heating chamber for heating heavily aged coarse aggregate, a fourth heating chamber for heating medium aggregate, a fifth heating chamber for heating fine aggregate, and a sixth heating chamber for heating mineral powder.

[0014] The first heating chamber uses a microwave hot air combined heating method, the second heating chamber uses an infrared hot air combined heating method, the third heating chamber uses a segmented gradient heating method, the fourth heating chamber uses an infrared vibration fluidization heating method, the fifth heating chamber uses a spiral conveying heating method, and the sixth heating chamber uses an indirect heating method.

[0015] Preferably, the regenerant addition module includes a temperature homogenization chamber connected to the discharge side of the conveyor unit, a loss-in-weight scale fixedly installed at the bottom of the temperature homogenization chamber, a chute provided below the temperature homogenization chamber, and an atomizing nozzle group fixedly installed in a circular array on the inner wall of the chute, the atomizing nozzle group being controlled by a solenoid valve.

[0016] A regenerant supply unit is provided outside the chute. The regenerant supply unit includes a regenerant storage tank. An electric regulating valve and a gear metering pump are fixedly installed on the top of the regenerant storage tank. A pressure sensor is fixedly installed at the output end of the gear metering pump. A delivery pipeline is connected to the output end of the gear metering pump. A flow sensor is fixedly installed on the side of the delivery pipeline that connects to the outer wall of the chute. The atomizing nozzle assembly is connected to the delivery pipeline.

[0017] Preferably, the mixing and discharging module includes a premixing pot connected to a chute via a feed inlet, a mixing pot located below the premixing pot, a plurality of feeding ports being provided at the top of the mixing pot, and the bottom of the premixing pot being connected to one of the feeding ports via a gate pipe.

[0018] The mixing and discharging module also includes a new aggregate bin, a new asphalt storage tank, and a new mineral powder bin. The new aggregate bin, the new asphalt storage tank, and the new mineral powder bin are connected to the mixing pot through three other feeding ports. Both the premixing pot and the mixing pot adopt a horizontal twin-shaft mixing structure.

[0019] A flue gas purification device for a RAP material recycling system includes a fume hood pipeline fixedly installed on a premixing pot and a mixing pot. One end of the fume hood pipeline is fixedly connected to a cyclone dust collector. One side of the cyclone dust collector is connected to a recovery ash hopper, and the other side of the cyclone dust collector is connected to a shell-and-tube heat exchanger. The outer side of the shell-and-tube heat exchanger is provided with a hot side port and a cold side port. The cold side port is connected to a heating chamber through a duct.

[0020] Preferably, a condensing heat exchanger is fixedly connected to the hot side port, a heat storage ceramic body is connected to one side of the condensing heat exchanger, and a bag filter and an electrostatic precipitator for recovering condensed asphalt fumes, water vapor and tar are fixedly connected to the other side of the condensing heat exchanger.

[0021] (III) Beneficial Effects

[0022] Compared with the prior art, the present invention provides a staged flexible heating RAP material regeneration system and a matching flue gas purification device, which has the following beneficial effects:

[0023] 1. This graded flexible heating RAP material recycling system and its supporting flue gas purification device classify materials according to particle size and asphalt aging degree, and treat the material characteristics differently, effectively improving the targeting of RAP material recycling and the activation effect of aged asphalt. By adopting a six-chamber independent and multi-heat source flexible heating process, it matches exclusive heating methods for different materials, avoiding overheating and aging of fine aggregates and insufficient heating of coarse aggregates, and significantly reducing the secondary aging rate of asphalt.

[0024] 2. This graded flexible heating RAP material recycling system and its supporting flue gas purification device adopt a two-stage mixing method. First, the recycled material is homogeneously pre-mixed and deeply activated, and then it is mixed with new aggregate and new asphalt in a gradient. This allows for more thorough integration of the old and new materials, ensuring the stable road performance of the finished mixture. At the same time, a flue gas waste heat recovery system is constructed, which greatly improves energy utilization and effectively reduces the overall production energy consumption of the system. Through the flue gas purification device, cyclone dust removal, condensation oil removal, bag dust removal and electrostatic precipitator are used for synergistic treatment, effectively removing asphalt fumes, dust and harmful substances. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the components of the RAP material recycling system of the present invention;

[0026] Figure 2 This is a schematic diagram of the preprocessing grading module of the present invention;

[0027] Figure 3 This is a schematic diagram of the flexible heating module of the present invention;

[0028] Figure 4 This is a schematic diagram of the regenerant addition module of the present invention;

[0029] Figure 5 This is a schematic diagram of the regenerant supply unit of the present invention;

[0030] Figure 6 This is a schematic diagram of the mixing and discharging module of the present invention;

[0031] Figure 7 This is a schematic diagram of the components of the flue gas purification device of the present invention.

[0032] In the diagram: 1. RAP main silo; 2. Pre-treatment and grading module; 201. Vibrating feeder; 202. First belt conveyor; 203. Electromagnetic separator; 204. Crusher; 205. Elevator; 206. Air separator; 207. Vibrating chamber; 208. Second belt conveyor; 209. Sorting robot; 3. Flexible heating module; 301. Storage silo; 302. Powder metering instrument; 303. Conveyor unit; 3031. First scraper conveyor; 3032. Second scraper conveyor; 3033. Third scraper conveyor; 3034. Vibrating conveyor; 3035. Screw conveyor; 304. Heating chamber; 3041. First heating chamber; 3042. Second heating chamber; 3043. Third heating chamber; 3044. Fourth heating chamber; 3045. Fifth heating chamber; 3046. Sixth heating chamber; 4. Regenerant addition module; 401. Temperature homogenization chamber; 402. Loss-in-weight scale; 403. Sluice box; 404. Atomizing nozzle assembly; 405. Regenerant supply unit; 4051. Regenerant storage tank; 4052. Electric regulating valve; 4053. Gear metering pump; 4054. Pressure sensor; 4055. Infusion pipeline; 4056. Flow sensor; 5. Mixing... 501. Combined discharge module; 502. Premixing pot; 503. New aggregate silo; 504. New asphalt storage tank; 505. New mineral powder silo; 6. Receiving hopper; 7. Layered vibrating screen; 8. Fume hood pipeline; 9. Cyclone dust collector; 10. Recovered ash hopper; 11. Shell and tube heat exchanger; 12. Condensing heat exchanger; 13. Thermal storage ceramic body; 14. Bag filter dust collector; 15. Electrostatic precipitator for tar. Detailed Implementation

[0033] 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. 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] Example 1

[0035] In this embodiment, the old RAP material in the RAP main silo 1 falls into the bottom receiving hopper 6 after the hydraulic gate is opened. The receiving hopper 6 evenly conveys the material to the vibrating feeder 201. The vibrating feeder 201 smoothly conveys the material to the first belt conveyor 202. During the belt conveying process, the electromagnetic iron separator 203 suspended at the top adsorbs and removes iron impurities from the material. After impurity removal, the material enters the crusher 204 through the receiving hopper 6 to complete the crushing operation. The crushed material is conveyed by the elevator 205 at the discharge port to the air separator 206 to separate and remove light impurities such as plastic and wood chips. The material after impurity removal enters the vibrating chamber 207. The layered vibrating screen 7 in the chamber completes the particle size screening according to the rule of decreasing screen hole diameter from top to bottom. The screened materials of each grade are discharged from the corresponding discharge port and conveyed by the second belt conveyor 208. During the transmission process, the sorting robot 209 equipped with a vision camera identifies and sorts the material according to the degree of asphalt aging, and finally completes the two-dimensional grading of RAP material particle size + degree of aging.

[0036] Example 2

[0037] In this embodiment, the pre-treated and graded RAP materials are temporarily stored in their respective storage bins 301. The powder metering instrument 302 at the bottom of the storage bin 301 accurately measures the material before conveying it to the corresponding conveyor unit 303. Slightly aged coarse aggregate is fed into the first heating chamber 3041 via the first scraper conveyor 3031 and heated using a microwave hot air composite method. Moderately aged coarse aggregate is fed into the second heating chamber 3042 via the second scraper conveyor 3032 and heated using an infrared hot air composite method. Severely aged... Coarse aggregate is fed into the third heating chamber 3043 via the third scraper conveyor 3033 and heated in a segmented gradient manner; medium aggregate is fed into the fourth heating chamber 3044 via the vibrating conveyor 3034 and heated in an infrared vibration fluidization manner; fine aggregate is fed into the fifth heating chamber 3045 via the screw conveyor 3035 and heated in a screw conveying manner; mineral powder is fed into the sixth heating chamber 3046 via the screw conveyor 3035 and heated in an indirect manner; the six heating chambers operate independently with temperature control to complete the differentiated flexible heating of materials at each level.

[0038] Example 3

[0039] In this embodiment, after heating, each stage of RAP material is transported to the corresponding temperature homogenization chamber 401 for temperature homogenization. The loss-in-weight scale 402 at the bottom of the temperature homogenization chamber 401 accurately weighs and measures the material. After measurement, the material falls into the chute 403. At the same time, the regenerant supply unit 405 starts working. The regenerant in the regenerant storage tank 4051 is pressurized and transported by the gear metering pump 4053 after the flow rate is regulated by the electric regulating valve 4052. The pressure sensor 4054 monitors the conveying pressure in real time, and the flow sensor 4056 monitors the conveying flow rate in real time. The regenerant is transported to the atomizing nozzle group 404 on the inner wall of the chute 403 through the liquid delivery pipeline 4055. The solenoid valve controls the atomizing nozzle group 404 to open, spraying the regenerant in a ring atomized manner onto the surface of the material, completing the precise and uniform addition of the regenerant and ensuring that the regenerant fully penetrates the aged asphalt.

[0040] Example 4

[0041] In this embodiment, the RAP material with added recycling agent is conveyed to the premixing pot 501 via chute 403. The premixing pot 501 adopts a horizontal twin-shaft mixing structure to homogenize and deeply activate the recycled material. After premixing, the bottom gate pipe of the premixing pot 501 is opened to convey the recycled material to the corresponding feeding port of the mixing pot 502. At the same time, the new aggregate bin 503, the new asphalt storage tank 504, and the new mineral powder bin 505 are respectively fed into the mixing pot 502 through the remaining feeding ports. The mixing pot 502 adopts a horizontal twin-shaft mixing structure to perform gradient mixing of the recycled material with the new aggregate, new asphalt, and new mineral powder, so that the new and old materials are fully integrated. After mixing, a qualified recycled asphalt mixture is formed and discharged.

[0042] Example 5

[0043] In this embodiment, the flue gas generated during the operation of the premixing pot 501 and the mixing pot 502 is collected in a sealed manner through the top fume hood pipe 8 and then transported to the cyclone dust collector 9. The cyclone dust collector 9 performs coarse dust removal on the flue gas, and the separated dust falls into the recovery ash hopper 10 for recycling. The flue gas after coarse dust removal enters the shell-and-tube heat exchanger 11. The heat carried by the flue gas is exchanged through the cold test port and then transported to the heating chamber 304 through the air duct to achieve waste heat recovery. The flue gas after heat exchange and cooling enters the condensing heat exchanger 12. The asphalt fumes, water vapor, and tar in the flue gas are condensed and recovered, and the heat storage ceramic body 13 helps to maintain the heat exchange temperature. The flue gas after deep cooling passes through the bag filter 14 to filter dust and the electrostatic precipitator 15 to remove residual tar. The flue gas after multi-stage purification meets the emission standards, completing the whole process of flue gas purification and waste heat recovery.

[0044] In summary, this graded flexible heating RAP material recycling system and its supporting flue gas purification device grade the materials according to their particle size and asphalt aging degree, and treat the material characteristics differently, effectively improving the targeting of RAP material recycling and the activation effect of aged asphalt. By adopting a six-chamber independent and multi-heat source flexible heating process, and matching exclusive heating methods to different materials, it avoids overheating and aging of fine aggregates and underheating of coarse aggregates, and significantly reduces the secondary aging rate of asphalt.

[0045] A two-stage mixing method is adopted. First, the recycled material is homogeneously premixed and deeply activated, and then it is mixed with new aggregate and new asphalt in a gradient. This allows for more thorough integration of the old and new materials, ensuring the stable road performance of the finished mixture. At the same time, a flue gas waste heat recovery system is constructed, which greatly improves energy utilization and effectively reduces the overall production energy consumption of the system. Through a flue gas purification device, asphalt fumes, dust and harmful substances are effectively removed through cyclone dust removal, condensation oil removal, bag dust removal and electrostatic tar removal.

[0046] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0047] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A graded flexible heated RAP material recycling system comprising a RAP bulk bin (1), characterized in that: It also includes a material regeneration system consisting of a pretreatment grading module (2), a flexible heating module (3), a regenerator addition module (4), and a mixing and discharging module (5).

2. A tiered flexible heated RAP material recycling system as defined in claim 1, wherein: A receiving hopper (6) is fixedly installed at the bottom of the RAP main silo (1). The RAP main silo (1) and the receiving hopper (6) are connected by a hydraulic gate. The pretreatment grading module (2) includes a vibrating feeder (201) located below the receiving hopper (6). A first belt conveyor (202) is provided on one side of the vibrating feeder (201). An electromagnetic separator (203) is suspended on the top of the first belt conveyor (202). A crusher (204) is provided on the side of the first belt conveyor (202) away from the vibrating feeder (201). The top of the crusher (204) is connected to the first belt conveyor (202) through the receiving hopper (6).

3. A tiered flexible heated RAP material recycling system as defined in claim 2, wherein: The crusher (204) is set with a discharge port on one side. An elevator (205) is fixedly installed at the discharge port. An air-separating separator (206) is fixedly installed on one side of the top of the elevator (205). A vibrating chamber (207) is set on one side of the air-separating separator (206). Several layered vibrating screens (7) are movably installed inside the vibrating chamber (207). The screen aperture of the layered vibrating screens (7) decreases from top to bottom. A discharge port is opened on the side of each layered vibrating screen (7) that contacts the inner wall of the vibrating chamber (207). A second belt conveyor (208) is set at each discharge port. A sorting robot (209) equipped with a vision camera is set on the outside of the second belt conveyor (208).

4. A tiered flexible heated RAP material recycling system as defined in claim 3, wherein: The flexible heating module (3) includes a storage silo (301) located on the side of the second belt conveyor (208) away from the discharge port. A powder meter (302) is fixedly installed at the bottom of the storage silo (301). A conveyor unit (303) is located below the storage silo (301). A heating chamber (304) is fixed on the outside of the conveyor unit (303). The conveyor unit (303) is divided into a first scraper conveyor (3031) for conveying lightly aged coarse aggregate, a second scraper conveyor (3032) for conveying moderately aged coarse aggregate, a third scraper conveyor (3033) for conveying heavily aged coarse aggregate, a vibrating conveyor (3034) for conveying medium aggregate, and a screw conveyor (3035) for conveying fine aggregate and mineral powder.

5. A graded flexible heating RAP material recycling system according to claim 4, characterized in that: The heating chamber (304) is divided into a first heating chamber (3041) for heating lightly aged coarse aggregate, a second heating chamber (3042) for heating moderately aged coarse aggregate, a third heating chamber (3043) for heating heavily aged coarse aggregate, a fourth heating chamber (3044) for heating medium aggregate, a fifth heating chamber (3045) for heating fine aggregate, and a sixth heating chamber (3046) for heating mineral powder. The first heating chamber (3041) adopts a microwave hot air composite heating method, the second heating chamber (3042) adopts an infrared hot air composite heating method, the third heating chamber (3043) adopts a segmented gradient heating method, the fourth heating chamber (3044) adopts an infrared vibration fluidization heating method, the fifth heating chamber (3045) adopts a spiral conveying heating method, and the sixth heating chamber (3046) adopts an indirect heating method.

6. The graded flexible heating RAP material recycling system according to claim 5, characterized in that: The regenerant addition module (4) includes a temperature homogenization chamber (401) connected to the discharge side of the conveyor unit (303), a loss-in-weight scale (402) is fixedly installed at the bottom of the temperature homogenization chamber (401), a chute (403) is provided below the temperature homogenization chamber (401), and an atomizing nozzle group (404) is fixedly installed in a ring array on the inner wall of the chute (403). The atomizing nozzle group (404) is controlled to open and close by a solenoid valve. A regenerant supply unit (405) is provided outside the chute (403). The regenerant supply unit (405) includes a regenerant storage tank (4051). An electric regulating valve (4052) and a gear metering pump (4053) are fixedly installed on the top of the regenerant storage tank (4051). A pressure sensor (4054) is fixedly installed at the output end of the gear metering pump (4053). A delivery pipeline (4055) is connected to the output end of the gear metering pump (4053). A flow sensor (4056) is fixedly installed on the side of the delivery pipeline (4055) that is connected to the outer wall of the chute (403). The atomizing nozzle group (404) is connected to the delivery pipeline (4055).

7. A graded flexible heating RAP material recycling system according to claim 6, characterized in that: The mixing and discharging module (5) includes a premixing pot (501) connected to a chute (403) via a feed inlet. A mixing pot (502) is provided below the premixing pot (501). Several feeding ports are provided on the top of the mixing pot (502). The bottom of the premixing pot (501) is connected to one of the feeding ports via a gate pipe. The mixing and discharging module (5) also includes a new aggregate silo (503), a new asphalt storage tank (504), and a new mineral powder silo (505). The new aggregate silo (503), the new asphalt storage tank (504), and the new mineral powder silo (505) are connected to the mixing pot (502) through three other feeding ports. Both the premixing pot (501) and the mixing pot (502) adopt a horizontal twin-shaft mixing structure.

8. A flue gas purification device supporting a RAP material regeneration system, comprising a hood pipeline (8) fixedly installed on a premixing pot (501) and a mixing pot (502), characterized in that: One end of the fume hood pipe (8) is fixedly connected to a cyclone dust collector (9). One side of the cyclone dust collector (9) is connected to a recovery ash hopper (10), and the other side of the cyclone dust collector (9) is connected to a shell-and-tube heat exchanger (11). The shell-and-tube heat exchanger (11) is provided with a hot side port and a cold side port on its outer side. The cold side port is connected to the heating chamber (304) through a duct.

9. A flue gas purification device for a RAP material regeneration system according to claim 8, characterized in that: A condensing heat exchanger (12) is fixedly connected to the hot side port. A heat storage ceramic body (13) is connected to one side of the condensing heat exchanger (12). A bag filter (14) and an electrostatic precipitator (15) for recovering condensed asphalt fumes, water vapor and tar are fixedly connected to the other side of the condensing heat exchanger (12).

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