An intermittent foamed asphalt plant-mixed cold-recycled mixture production system

Abstract

The utility model belongs to the technical field of road engineering, concretely relates to intermittent foamed asphalt plant mixing cold recycling mixture production system. The utility model carries out the innovative design to the limitation of prior art road engineering material production equipment, has the remarkable advantage in the recycling mixture performance optimization and production efficiency promotion: on the recycling mixture performance, effectively solved the uneven problem of traditional continuous equipment asphalt dispersion. Through the improvement to aggregate pretreatment unit, foamed asphalt generating unit, intermittent mixing unit and other equipment, realize foamed asphalt dispersion evenness coefficient of variation less than or equal to 10%. In the production efficiency aspect, the utility model controls single cycle time in less than or equal to 80s, compared with continuous equipment, significantly improves the gradation stability more than 20%. Not only speeds up the production rhythm, but also can ensure that every batch recycling mixture gradation is accurate and stable, reduces the quality problem and material waste caused by gradation fluctuation.

Description

Technical Field

[0001] This utility model belongs to the field of road engineering technology, specifically relating to an intermittent foamed asphalt plant-mixed cold recycled mixture production system. Background Technology

[0002] In the field of road engineering, cement-stabilized aggregate mixtures and foamed asphalt plant-mixed cold recycled mixtures are two commonly used materials. Their production equipment has its own characteristics, but it also has certain limitations.

[0003] Intermittent cement-stabilized aggregate mixture production equipment: Traditional intermittent cement-stabilized aggregate mixture production equipment (such as the WBZ series stabilized soil mixing plant) has the advantages of precise metering and batch mixing, making it suitable for the preparation of cement-stabilized materials. However, this type of equipment cannot be directly used for the production of foamed asphalt cold recycled mixtures, mainly because: 1) Lack of asphalt foaming and spraying equipment: Foamed asphalt cold recycled mixtures require dedicated asphalt foaming equipment and precision spraying equipment, while intermittent cement-stabilized aggregate mixture production equipment does not have this function. 2) No control system: Foamed asphalt requires a complete control system to complete the relevant instructions for foaming and spraying, but intermittent cement-stabilized aggregate production equipment does not have a relevant control system and cannot meet this requirement; 3) Mismatched mixing time: Current specifications stipulate that the mixing time of recycled foamed asphalt mixtures must be ≥45 seconds, but the timing control system of intermittent cement-stabilized aggregate mixture production equipment cannot meet this requirement.

[0004] Continuous foamed asphalt plant-mixed cold recycled asphalt production equipment: Most plant-mixed cold recycling equipment on the market is a continuous production system. Although it can achieve continuous operation, it suffers from problems such as insufficient gradation control accuracy and uneven asphalt dispersion. For example, projects require a coefficient of variation of ≤10% for the uniformity of foamed asphalt dispersion, which continuous equipment struggles to meet. In contrast, intermittent equipment has advantages in metering accuracy and mixing uniformity, but requires targeted modifications to existing systems to meet the production requirements of foamed asphalt cold recycled asphalt mixtures.

[0005] In view of this, this utility model is proposed to solve the problems existing in the existing equipment. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide an intermittent foamed asphalt plant-mixed cold recycled mixture production system.

[0007] To achieve the above objectives, the present invention provides the following technical solution: This utility model provides an intermittent foamed asphalt plant-mixed cold recycled aggregate production system, comprising: The aggregate pretreatment unit includes an asphalt mixture recycled material crushing and screening unit and a new aggregate feeding device; The foamed asphalt generation unit includes an interconnected asphalt conveying device, a foamed asphalt spraying device, and a foamed asphalt generation device. Intermittent mixing unit includes a twin-shaft forced mixer for uniformly mixing the recycled aggregate obtained from the asphalt mixture recycling crushing and screening unit, the new aggregate in the new aggregate feeding device, the foamed asphalt sprayed by the foamed asphalt spraying device, the cement in the active material feeding device, and the water in the water storage system. The central controller is electrically connected to the control devices in the aggregate pretreatment unit, the foamed asphalt generation unit, the active material feeding device, the water storage system, and the twin-shaft forced mixer.

[0008] Specifically, the asphalt mixture recycling crushing and screening unit includes a primary crusher for crushing large pieces of recycled material and a multi-stage screening device for screening the crushed recycled material. The multi-stage screening device includes multiple layers of screens with different particle sizes. A belt conveyor system is correspondingly set under the screen with the required particle size. A recycled aggregate weighing device is provided between the feed end of the multi-stage screening device and the belt conveyor system. The discharge end of the belt conveyor system is connected to the feed port of the twin-shaft forced mixer.

[0009] Furthermore, a temporary storage bin for the mixed material is provided between the discharge end of the belt conveyor system and the twin-shaft forced mixer.

[0010] Furthermore, the belt conveyor system is equipped with an anti-deviation device and a tensioning mechanism.

[0011] Specifically, the asphalt conveying device includes an asphalt storage tank, which sequentially transports asphalt to the foamed asphalt generating device via an asphalt pump and an asphalt outlet. The asphalt pump has a metering function, and the central control system controls the pump speed according to the required asphalt quantity. The asphalt in the asphalt storage tank is high-temperature asphalt. The asphalt storage tank includes a tank body and an insulation layer wrapped around the tank body. The asphalt pipeline from the asphalt conveying device to the asphalt outlet is fitted with a heat-conducting oil coil for insulating the asphalt, ensuring the temperature of the asphalt entering the foamed asphalt generating device. The heat-conducting oil coil is equipped with a heater for heating the heat-conducting oil, and the heater is electrically connected to the central controller.

[0012] Specifically, the foamed asphalt generating device includes a high-pressure air storage tank, an air valve connected to the high-pressure air storage tank, a compressed air outlet connected to the air valve, a first water pump for pumping water, and a water pipe outlet connected to the first water pump. The compressed air outlet, the water pipe outlet, and the asphalt conveying device converge in a gas-liquid mixing chamber, which is connected to a foamed asphalt spraying device.

[0013] Specifically, the foamed asphalt spraying device includes a foamed asphalt foaming chamber connected to the foamed asphalt generating device, and a gas-liquid dual-fluid high-pressure nozzle for spraying foamed asphalt connected to the foamed asphalt foaming chamber. The foamed asphalt foaming chamber is equipped with a pressure sensor for detecting gas pressure and a temperature sensor for detecting foamed asphalt temperature. Both the pressure sensor and the temperature sensor are electrically connected to a central controller. The temperature sensor is linked to a heater for heating the heat transfer oil through the central controller. The temperature sensor detects the temperature of the foamed asphalt generated in the foamed asphalt foaming chamber in real time and feeds back the temperature of the generated foamed asphalt to the central controller. Based on the obtained temperature data, the central controller adjusts the heating temperature of the heater and further adjusts the temperature of the heat transfer oil, thereby maintaining a suitable temperature for the asphalt in the asphalt pipeline, ensuring that the generated foamed asphalt is at a suitable temperature, and ensuring the quality of the recycled mixture.

[0014] Specifically, when the pressure sensor detects an abnormal air pressure in the foaming chamber of the foamed asphalt, it is usually necessary to replace the backup air line to meet production needs. Scenarios involving abnormal air pressure include: When the pressure sensor detects that the air pressure in the foaming chamber of the foamed asphalt is too low (e.g., <0.3MPa), it leads to insufficient atomization by the gas-liquid dual-fluid high-pressure nozzle, resulting in increased foamed asphalt particle size (>100μm) and decreased uniformity of the recycled mixture. When the pressure sensor detects that the air pressure in the foamed asphalt cavity is too high (e.g., >0.8MPa), it may damage the gas-liquid dual-fluid high-pressure nozzle or cause pipeline leakage.

[0015] Specifically, the new aggregate feeding device includes a new aggregate silo, a new aggregate unloading device connected to the new aggregate silo, and a new aggregate weighing device connected to the new aggregate unloading device. The new aggregate weighing device is connected to the feed inlet of the twin-shaft forced mixer. Preferably, the new aggregate is a granular material added to the mixture to provide a skeleton and filler, including crushed stone, gravel, manufactured sand, stone chips, sand, etc.

[0016] Specifically, the water storage system includes a water storage tank, a second water pump connected to the water storage tank, and a water outlet connected to the second water pump. The water outlet is connected to the feed inlet of the twin-shaft forced mixer.

[0017] Specifically, the active material feeding device includes an active material silo, a screw conveyor connected to the active material silo, and an active material weighing device connected to the screw conveyor. The active material weighing device is connected to the feed inlet of a twin-shaft forced mixer. Preferably, the active material is cement.

[0018] Specifically, the twin-shaft forced mixer includes a mixing tank, two opposing synchronously rotating mixing blades driven by motors, and an arc-shaped discharge gate driven by a hydraulic cylinder; one end of the hydraulic cylinder is fixed to the mixing tank, and the other end is fixedly connected to the arc-shaped discharge gate.

[0019] Furthermore, the motor has a power of 55kW, the gear ratio of the hardened gear reducer is 25:1, and the rotation speed of the stirring blade is 25~30rpm; the stirring blade is arranged in a logarithmic spiral, the blade is at an angle of 45° to the shaft, the blade is made of NM400 wear-resistant steel (12mm thick), and the gap between the blade tip and the liner is ≤3mm. Furthermore, the opening and closing time of the arc-shaped discharge gate driven by the hydraulic cylinder is ≤5s. A position sensor (inductive or magnetic induction type) is also installed next to the arc-shaped discharge gate to provide feedback on the opening and closing status of the arc-shaped discharge gate. When the arc-shaped discharge gate moves to the fully open or fully closed position, the position sensor detects the position of the arc-shaped discharge gate. The proximity switch outputs a high-level (e.g., 24VDC) signal, indicating that "the arc-shaped discharge gate is in position". When the central controller receives the fully open signal, it allows the finished material to enter the temporary storage bin and initiates the material receiving prompt of the transport vehicle. When the central controller receives the fully closed signal, it unlocks the feeding permission of the weighing hopper and allows the next production cycle to start. If the arc-shaped discharge gate is not completely closed (no fully closed signal), the central controller prohibits the mixer from starting to prevent leakage of the recycled mixture. If the arc-shaped discharge gate is stuck (not in position within time limit), the central controller triggers an emergency stop and alarm.

[0020] The control process of the central controller is as follows: asphalt mixture recycled material is crushed and screened to obtain recycled aggregate → mixed with new aggregate for 10s → foamed asphalt is sprayed and mixed for 15s → cement is added → water is added and mixed for 35s → unloading, with a total time of ≥60s and an error of ±0.5s for each stage.

[0021] The central controller stores at least 50 sets of formula parameters (such as recycled aggregate content ≥70%, new aggregate content ≤30%, foamed asphalt 2.5%~3.5%, cement 1%~3%, water 2%~4%).

[0022] Compared with the prior art, the technical solution provided by this utility model has the following beneficial effects: This utility model innovatively addresses the limitations of existing road engineering material production equipment, and has significant advantages in optimizing the performance of recycled mixtures and improving production efficiency: Regarding the performance of recycled asphalt mixtures, this invention effectively solves the problem of uneven asphalt dispersion in traditional continuous equipment. Through improvements to the aggregate pretreatment unit, foamed asphalt generation unit, and intermittent mixing unit, the coefficient of variation for the uniformity of foamed asphalt dispersion is ≤10%. Compared to the large asphalt dispersion error inherent in continuous equipment, this invention allows for a full and uniform distribution of foamed asphalt in the recycled mixture, ensuring stable and consistent material properties across all components. This effectively enhances the overall performance of the recycled mixture, guarantees the load-bearing capacity and durability of the road after paving, and reduces problems such as road surface cracking and damage caused by insufficient material properties. In terms of production efficiency, this invention breaks through the limitations of traditional equipment. By controlling the single-cycle time to ≤80s, it significantly improves gradation stability by over 20% compared to continuous equipment. This not only accelerates the production pace but also ensures accurate and stable gradation in each batch of recycled mixtures, reducing quality problems and material waste caused by gradation fluctuations. This achieves efficient and high-quality production, effectively reducing production costs and improving enterprise economic benefits. Furthermore, compared to the limitation of intermittent cement-stabilized aggregate recycled mixture production equipment in producing foamed asphalt cold recycled mixtures, this invention expands the application scope of the equipment, meeting the diverse production needs of the road engineering field and providing more reliable technical equipment support for industry development. Attached Figure Description

[0023] The accompanying drawings are incorporated in and form part of this specification, and together with the description, serve to explain the principles of this invention.

[0024] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the foamed asphalt generating device of this utility model. Figure 3 This is a schematic diagram of the control logic of this utility model.

[0026] Among them, 1 is the asphalt mixture recycled material crushing and screening unit; 11 is the primary crusher; 12 is the recycled aggregate weighing device; 13 is the multi-stage screening device; 3 is the belt conveyor system; 4 is the asphalt conveying device; 41 is the asphalt storage tank; 42 is the asphalt pump; 43 is the asphalt outlet; 5 is the foamed asphalt spraying device; 51 is the foamed asphalt foaming chamber; 52 is the gas-liquid dual-fluid high-pressure nozzle; 6 is the foamed asphalt generating device; 61 is the gas-liquid mixing chamber; 62 is the compressed air outlet; 63 is the water pipe outlet; 64 is the high-pressure air storage tank; 65 is the air valve; 66 is the first water pump; 7 is the twin-shaft forced mixer; 71 is the mixing tank; 72 is the mixing blade; 73 is the arc-shaped discharge gate; 74 is the mixture temporary storage bin; 8 is the water storage system; 81 is the water storage tank; 82 is the water outlet; 83 is the second water pump; 9 is the new aggregate feeding device; 91 is the new aggregate bin; 92 is the new aggregate silo; 93 is a new aggregate unloading device; 10 is a new aggregate weighing device; 10 is an active material feeding device; 101 is an active material silo; 102 is a screw conveyor; 103 is an active material weighing device. Detailed Implementation

[0027] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. The embodiments described below do not represent all embodiments consistent with this invention. Rather, they are merely examples consistent with some aspects of this invention as detailed in the appended claims.

[0028] To enable those skilled in the art to better understand the technical solution of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. Example

[0029] See Figure 1-3 As shown, this embodiment provides an intermittent foamed asphalt plant-mixed cold recycled aggregate production system, including: The aggregate pretreatment unit includes an asphalt mixture recycled material crushing and screening unit 1 and a new aggregate feeding device 9; The foamed asphalt generation unit includes an interconnected asphalt conveying device 4, a foamed asphalt spraying device 5, and a foamed asphalt generation device 6. The intermittent mixing unit includes a twin-shaft forced mixer 7 for uniformly mixing the recycled aggregate obtained from the asphalt mixture recycling crushing and screening unit 1, the new aggregate in the new aggregate feeding device 9, the foamed asphalt sprayed by the foamed asphalt spraying device 5, the cement in the active material feeding device 10, and the water in the water storage system 8. The central controller is electrically connected to the control devices in the aggregate pretreatment unit, the foamed asphalt generation unit, the new aggregate feeding device 9, the active material feeding device 10, the water storage system 8, and the twin-shaft forced mixer 7.

[0030] Specifically, the asphalt mixture recycling crushing and screening unit 1 includes a primary crusher 11 for crushing large pieces of recycled material and a multi-stage screening device 13 for screening the crushed recycled material. The multi-stage screening device 13 includes multiple layers of screens with different apertures (such as 3 or 4 layers of screens with different apertures, such as 0~5mm, 5~10mm, 10~20mm, etc.). A belt conveyor system 3 is correspondingly set under the screen with the required aperture. A recycled aggregate weighing device 12 is provided between the feed end of the multi-stage screening device 13 and the belt conveyor system 3. Recycled aggregate is produced by selecting recycled aggregate with a suitable particle size. That is, the discharge end of the belt conveyor system 3 carrying recycled aggregate with the required particle size is connected to the feed inlet of the twin-shaft forced mixer 7. Recycled aggregate with other particle sizes is transported to the warehouse for use. The primary crusher 11 is a jaw crusher or an impact crusher, and the inclination angle of each layer of screen is adjustable, with an adjustment range of 15°~25°.

[0031] Furthermore, a mixed material storage bin 74 is provided between the discharge end of the belt conveyor system 3 and the twin-shaft forced mixer 7.

[0032] Furthermore, each of the belt conveyor systems 3 is equipped with an anti-deviation device and a tensioning mechanism. The anti-deviation device and the tensioning mechanism are both auxiliary machines commonly used in engineering. Although they are not explicitly stated in the text, they do not affect the understanding.

[0033] Specifically, the asphalt conveying device 4 includes an asphalt storage tank 41, which sequentially transports asphalt to the foamed asphalt generating device 6 via an asphalt pump 42 and an asphalt outlet 43; the asphalt in the asphalt storage tank 41 is high-temperature asphalt; the asphalt storage tank 41 includes a tank body and an insulation layer wrapped around the tank body; the asphalt pipeline from the asphalt conveying device 4 to the asphalt outlet 43 is fitted with a heat-conducting oil coil for insulating the asphalt to ensure the temperature of the asphalt entering the foamed asphalt generating device 6; the heat-conducting oil coil is equipped with a heater for heating the heat-conducting oil, and the heater is electrically connected to the central controller.

[0034] Specifically, the foamed asphalt generating device 6 includes a high-pressure air storage tank 64, an air valve 65 connected to the high-pressure air storage tank 64, a compressed air outlet 62 connected to the air valve 65, a first water pump 66 for pumping water, and a water pipe outlet 63 connected to the first water pump 66. The compressed air outlet 62, the water pipe outlet 63, and the asphalt conveying device 4 converge in the gas-liquid mixing chamber 61, which is connected to the foamed asphalt spraying device 5.

[0035] Specifically, the foamed asphalt spraying device 5 includes a foamed asphalt foaming chamber 51 connected to the foamed asphalt generating device 6, and a gas-liquid dual-fluid high-pressure nozzle 52 for spraying foamed asphalt, which is sequentially connected to the foamed asphalt foaming chamber 51. The foamed asphalt foaming chamber 51 is equipped with a pressure sensor for detecting gas pressure and a temperature sensor for detecting foamed asphalt temperature. Both the pressure sensor and the temperature sensor are electrically connected to the central controller. The temperature sensor is linked to the heater for heating the heat transfer oil through the central controller. The temperature sensor detects the temperature of the foamed asphalt generated in the foamed asphalt foaming chamber 51 in real time and feeds back the temperature of the generated foamed asphalt to the central controller. The central controller adjusts the heating temperature of the heater based on the obtained temperature data, and further adjusts the temperature of the heat transfer oil, thereby maintaining a suitable temperature for the asphalt in the asphalt pipeline, ensuring that the generated foamed asphalt is at a suitable temperature, and ensuring the quality of the recycled mixture.

[0036] Specifically, when the pressure sensor detects an abnormal air pressure in the foamed asphalt foaming chamber 51, it is usually necessary to replace the backup air line to meet production needs. Scenarios of abnormal air pressure include: When the pressure sensor detects that the air pressure in the foaming chamber 51 of the foamed asphalt is too low (e.g., <0.3MPa), it leads to insufficient atomization by the gas-liquid dual-fluid high-pressure nozzle 52, resulting in increased foamed asphalt particle size (>100μm) and decreased uniformity of the recycled mixture. When the pressure sensor detects that the air pressure in the foaming chamber 51 of the foamed asphalt is too high (e.g., >0.8MPa), it may damage the gas-liquid dual-fluid high-pressure nozzle 52 or cause pipeline leakage.

[0037] Specifically, the new aggregate feeding device 9 includes a new aggregate bin 91, a new aggregate unloading device 92 connected to the new aggregate bin 91, and a new aggregate weighing device 93 connected to the new aggregate unloading device 92. The new aggregate weighing device 93 is connected to the feed inlet of the twin-shaft forced mixer 7. Preferably, the aggregate is granular material that plays a skeleton and filling role in the mixture, including crushed stone, gravel, manufactured sand, stone chips, sand, etc. The recycled aggregate is the aggregate obtained after crushing and screening the recycled asphalt mixture, which is a mixture of asphalt and crushed stone, gravel, manufactured sand, stone chips, sand, etc.

[0038] Specifically, the water storage system 8 includes a water storage tank 81, a second water pump 83 connected to the water storage tank 81, and a water outlet 82 connected to the second water pump 83. The water outlet 82 is connected to the feed inlet of the twin-shaft forced mixer 7.

[0039] Specifically, the active material feeding device 10 includes an active material silo 101, a screw conveyor 102 connected to the active material silo 101, and an active material weighing device 103 connected to the screw conveyor 102. The active material weighing device 103 is connected to the feed inlet of the twin-shaft forced mixer 7. Preferably, the active material is cement.

[0040] Furthermore, the linkage logic of the foamed asphalt generation device is as follows: Asphalt demand → Central controller → Adjust asphalt pump speed, first water pump speed, and air valve opening; It should be noted that the central controller mainly adjusts the speed of the asphalt pump 42 according to actual needs, thereby adjusting the amount of foamed asphalt entering the foamed asphalt foaming chamber 51, and thus controlling the amount of foamed asphalt entering the twin-shaft forced mixer 7.

[0041] Specifically, the twin-shaft forced mixer 7 includes a mixing tank 71, two opposing synchronously rotating mixing blades 72 driven by motors, and an arc-shaped discharge gate 73 driven by a hydraulic cylinder; one end of the hydraulic cylinder is fixed to the mixing tank 71, and the other end is fixedly connected to the arc-shaped discharge gate 73.

[0042] Furthermore, the motor has a power of 55kW, and the stirring blade 72 rotates at a speed of 25~30rpm; the blades of the stirring blade 72 are arranged in a logarithmic spiral, the blades are at an angle of 45° to the shaft, the blades are made of NM400 wear-resistant steel (12mm thick), and the gap between the blade tip and the liner is ≤3mm. Furthermore, the opening and closing time of the hydraulic cylinder-driven arc-shaped unloading gate 73 is ≤5s. A position sensor (inductive or magnetic induction type) is also provided next to the arc-shaped unloading gate 73 to provide feedback on the opening and closing status of the arc-shaped unloading gate. When the arc-shaped unloading gate 73 moves to the fully open or fully closed position, the position sensor detects the position of the arc-shaped unloading gate 73. The proximity switch outputs a high-level (e.g., 24VDC) signal, indicating that "the arc-shaped unloading gate 73 is in position". When the central controller receives the fully open signal, it allows the finished material to enter the temporary storage bin and initiates the material receiving prompt of the transport vehicle. When the central controller receives the fully closed signal, it unlocks the feeding permission of the weighing hopper and allows the next production cycle to start. If the arc-shaped unloading gate 73 is not completely closed (no fully closed signal), the central controller prohibits the mixer from starting to prevent leakage of the recycled mixture. If the arc-shaped unloading gate 73 is stuck (not in position after timeout), the central controller triggers an emergency stop and alarm.

[0043] The control process of the central controller is as follows: asphalt mixture recycled material is milled, crushed and screened to obtain recycled aggregate → mixed with new aggregate for 10s → foamed asphalt is sprayed and mixed for 15s → cement is added → water is added and mixed for 35s → unloading, with a total time of ≥60s and an error of ±0.5s for each stage.

[0044] The central controller stores at least 50 sets of formula parameters (such as recycled aggregate content ≥70%, new aggregate content ≤30%, foamed asphalt 2.5%~3.5%, cement 1%~3%, water 2%~4%).

[0045] This embodiment provides an operation method for an intermittent foamed asphalt plant-mixed cold recycled aggregate production system, as detailed below: First, the asphalt-mixed recycled milled aggregate is fed into the primary crusher 11. Then, the recycled aggregate of different particle sizes is screened out by the multi-stage screening device 13 and weighed in the recycled aggregate weighing device 12. Then, it is conveyed to the twin-shaft forced mixer 7 through the belt conveyor system 3. Then, the new aggregate is discharged from the new aggregate silo 91 through the new aggregate unloading device 92 to the new aggregate weighing device 93. The new aggregate weighing device 93 weighs the new aggregate and then sends the weighed new aggregate into the twin-shaft forced mixer 7 through the belt conveyor system 3. It is mixed for 10 seconds. Before entering the twin-shaft forced mixer 7 from the belt conveyor system 3, the recycled aggregate and the new aggregate first enter the mixture temporary storage silo 74 and then enter the twin-shaft forced mixer 7 at the appropriate time according to the process. Simultaneously, valve 66 delivers compressed air from high-pressure storage tank 64 to gas-liquid mixing chamber 61; at the same time, first water pump 66 delivers water to gas-liquid mixing chamber 61; furthermore, the base asphalt is delivered from asphalt storage tank 41 to gas-liquid mixing chamber 61 via asphalt pump 42; high-pressure gas and water first come into contact and interact violently in a very short time, generating a large number of tiny mist-like water vapor mixtures. These mist-like water vapor mixtures are sprayed into the high-temperature asphalt flow under high pressure, and the three mix instantly, resulting in a violent physical reaction (mainly water flash evaporation). The violent flash evaporation and gas expansion generate enormous, explosive energy, which stretches and tears the high-temperature, low-viscosity asphalt, forming a thin film; newly generated steam bubbles and expanding air are wrapped and separated by these asphalt films. In a very short time (the timescale is in milliseconds), a large number of tiny, independent, closed bubbles wrapped by asphalt films are formed, and the overall volume expands rapidly several to ten times, forming a foam-like structure to form foamed asphalt, which then enters the foamed asphalt foaming chamber 51; High-pressure gas is used to send foamed asphalt from foamed asphalt foaming chamber 51 to gas-liquid dual-fluid high-pressure nozzle 52, and spray it in a fan-shaped mist onto the mixture in twin-shaft forced mixer 7. Twin-shaft forced mixer 7 is stirred for 15 seconds. At this time, cement in active material feeding device 10 is sent to active material weighing device 103 by screw conveyor 102. After being weighed by active material weighing device 103, cement and water in water storage system 8 are added to twin-shaft forced mixer 7 for mixing and stirring for 35 seconds. In the twin-shaft forced mixer 7, the mixture is first stirred until uniform by two opposing synchronously rotating mixing blades 72 to obtain a recycled mixture. Then, the arc-shaped discharge gate 73 is opened to send the recycled mixture into a temporary storage bin for subsequent use. Finally, the arc-shaped discharge gate 73 is closed before the next round of production begins.

[0046] It should also be noted that, see Figure 3 As shown, the central controller controls the new aggregate feeding device 9 to transport qualified new aggregate to the twin-shaft forced mixer 7; the central controller controls the primary crusher 11, the multi-stage screening device 13, and the belt conveyor system 3 to transport the crushed recycled aggregate required for production to the twin-shaft forced mixer 7; the central controller controls the foamed asphalt generating device 6 and the foamed asphalt spraying device 5 to atomize and spray the prepared foamed asphalt into the twin-shaft forced mixer 7, and then the central controller controls the entire production process to be less than or equal to 80 seconds, finally producing recycled mixture (finished material).

[0047] In addition, the recycled aggregate weighing device 12, the new aggregate weighing device 93, and the active material weighing device 103 mentioned in the text are all equipped with openable and closable unloading devices to facilitate weighing and unloading; the mixed material storage bin 74 is equipped with an openable and closable unloading device to facilitate the entry of recycled aggregate and new aggregate into the twin-shaft forced mixer 7.

[0048] The above description is merely a specific embodiment of this utility model, enabling those skilled in the art to understand or implement it. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this utility model.

[0049] It should be understood that this utility model is not limited to the content already described above, and various modifications and changes can be made without departing from its scope. The scope of this utility model is limited only by the appended claims.

Claims

1. An intermittent foamed asphalt plant-mixed cold recycled aggregate production system, characterized in that, include: The aggregate pretreatment unit includes an asphalt mixture recycled material crushing and screening unit and a new aggregate feeding device; The foamed asphalt generation unit includes an interconnected asphalt conveying device, a foamed asphalt spraying device, and a foamed asphalt generation device. Intermittent mixing unit includes a twin-shaft forced mixer for uniformly mixing the recycled aggregate obtained from the asphalt mixture recycling crushing and screening unit, the new aggregate in the new aggregate feeding device, the foamed asphalt sprayed by the foamed asphalt spraying device, the active material in the active material feeding device, and the water in the water storage system. The central controller is electrically connected to the aggregate pretreatment unit, the foamed asphalt generation unit, the active material feeding device, the water storage system, and the twin-shaft forced mixer.

2. The intermittent foamed asphalt plant-mixed cold recycled aggregate production system according to claim 1, characterized in that, The asphalt mixture recycling crushing and screening unit includes a primary crusher for crushing large pieces of recycled material and a multi-stage screening device for screening the crushed recycled material. The multi-stage screening device includes multiple layers of screens with different particle sizes. A belt conveyor system is correspondingly set under the screen with the required particle size. A recycled aggregate weighing device is provided between the feed end of the multi-stage screening device and the belt conveyor system. The discharge end of the belt conveyor system is connected to the feed port of a twin-shaft forced mixer.

3. The intermittent foamed asphalt plant-mixed cold recycled aggregate production system according to claim 2, characterized in that, A temporary storage bin for the mixed material is provided between the discharge end of the belt conveyor system and the twin-shaft forced mixer.

4. The intermittent foamed asphalt plant-mixed cold recycled aggregate production system according to claim 1, characterized in that, The asphalt conveying device includes an asphalt storage tank, which sequentially transports asphalt to the foamed asphalt generating device via an asphalt pump and an asphalt outlet.

5. The intermittent foamed asphalt plant-mixed cold recycled aggregate production system according to claim 1, characterized in that, The foamed asphalt generating device includes a high-pressure air storage tank, an air valve connected to the high-pressure air storage tank, a compressed air outlet connected to the air valve, a first water pump for pumping water, and a water pipe outlet connected to the first water pump. The compressed air outlet, the water pipe outlet, and the asphalt conveying device converge in a gas-liquid mixing chamber, which is connected to a foamed asphalt spraying device.

6. The intermittent foamed asphalt plant-mixed cold recycled aggregate production system according to claim 1, characterized in that, The foamed asphalt spraying device includes a foamed asphalt foaming chamber connected to a foamed asphalt generating device, and a gas-liquid dual-fluid high-pressure nozzle for spraying foamed asphalt connected to the foamed asphalt foaming chamber.

7. The intermittent foamed asphalt plant-mixed cold recycled aggregate production system according to claim 1, characterized in that, The new aggregate feeding device includes a new aggregate silo, a new aggregate unloading device connected to the new aggregate silo, and a new aggregate weighing device connected to the new aggregate unloading device. The new aggregate weighing device is connected to the feed inlet of the twin-shaft forced mixer.

8. The intermittent foamed asphalt plant-mixed cold recycled aggregate production system according to claim 1, characterized in that, The water storage system includes a water storage tank, a second water pump connected to the water storage tank, and a water outlet connected to the second water pump. The water outlet is connected to the feed inlet of the twin-shaft forced mixer.

9. The intermittent foamed asphalt plant-mixed cold recycled aggregate production system according to claim 1, characterized in that, The active material feeding device includes an active material silo, a screw conveyor connected to the active material silo, and an active material weighing device connected to the screw conveyor. The active material weighing device is connected to the feed inlet of a twin-shaft forced mixer.

10. The intermittent foamed asphalt plant-mixed cold recycled aggregate production system according to claim 1, characterized in that, The twin-shaft forced mixer includes a mixing tank, two opposing synchronously rotating mixing blades driven by motors, and an arc-shaped discharge gate driven by a hydraulic cylinder; one end of the hydraulic cylinder is fixed to the mixing tank, and the other end is fixedly connected to the arc-shaped discharge gate.

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