Waste heat utilization equipment for asphalt production

Abstract

The utility model provides a kind of waste heat utilization equipment for asphalt production, it is related to asphalt mixture production technical field, including: drying roller, circulation component, circulation component includes roller exhaust pipe, shell-and-tube heat exchanger, return air duct, hot air duct, regenerative material bin and circulating fan, one end of roller exhaust pipe is connected the exhaust port of drying roller, the other end is connected the flue gas inlet of shell-and-tube heat exchanger, the flue gas outlet of shell-and-tube heat exchanger is used to connect dust removal system, shell-and-tube heat exchanger is equipped with air inlet and air outlet, one end of hot air duct is connected the air outlet of shell-and-tube heat exchanger, the other end is connected the bottom of regenerative material bin, for sending heated air into regenerative material bin inside, solve the problem of lack of efficient regenerative material preheating means in prior art, regenerative material blending rate is low, mixing energy consumption is high and flue gas waste heat is not combined with regenerative material preheating, leading to energy waste.

Description

Technical Field

[0001] This utility model relates to the field of asphalt mixture production technology, and in particular to a waste heat utilization device for asphalt production. Background Technology

[0002] During asphalt production, the high-temperature flue gas discharged from the drying drum contains a large amount of waste heat. Traditional equipment usually cools the flue gas directly before discharging it, or uses it only for simple preheating of aggregates, failing to fully utilize the heat energy. Although some systems are equipped with waste heat recovery devices, they mostly use hydrothermal recovery or heat transfer oil heating methods, which are complex in structure, costly, and difficult to promote in small and medium-sized mixing plants.

[0003] However, existing technologies lack efficient preheating methods for recycled bitumen (RAP), resulting in low RAP blending rates and high mixing energy consumption. Furthermore, the waste heat from flue gas is not integrated with the RAP preheating process, leading to energy waste.

[0004] Therefore, it is necessary to provide a waste heat recovery device for asphalt production to solve the above problems. Utility Model Content

[0005] To solve the above-mentioned technical problems, this utility model provides a waste heat utilization device for asphalt production.

[0006] This utility model provides a waste heat recovery device for asphalt production, comprising: Drying drum; The circulation assembly includes a drum exhaust pipe, a shell-and-tube heat exchanger, a return air duct, a hot air duct, a recycled material silo, and a circulating fan; The shell-and-tube heat exchanger has a flue gas inlet and a flue gas outlet at both ends, and an air inlet and an air outlet at both ends of the circumferential surface of the shell-and-tube heat exchanger. One end of the drum exhaust pipe is connected to the exhaust port of the drying drum, and the other end is connected to the flue gas inlet; The tubular flue gas outlet is used to connect to the dust removal system; One end of the hot air duct is connected to an air outlet, and the other end is connected to the bottom of the recycled material silo, which is used to send heated air into the recycled material silo. One end of the return air duct is connected to the vent at the top of the side wall of the recycled material silo, and the other end is connected to the air intake of the circulating fan. The outlet of the circulating fan is connected to the air inlet, forming a closed hot air circulation loop; The bottom of the recycled material silo is equipped with an air distribution plate, through which hot air penetrates the recycled material layer from bottom to top, achieving uniform heating.

[0007] Preferably, the air distribution plate is provided with a plurality of evenly distributed through holes with a diameter of 5 to 20 mm, which are used to distribute hot air evenly and prevent recycled material from leaking down.

[0008] Preferably, the circulating fan is a high-temperature resistant centrifugal fan.

[0009] Preferably, both the hot air duct and the return air duct are made of metal, and both the hot air duct and the return air duct have an insulation layer on their circumferential surfaces to reduce heat loss.

[0010] Compared with related technologies, the waste heat recovery equipment for asphalt production provided by this utility model has the following beneficial effects: 1. This utility model introduces the high-temperature flue gas discharged from the drying drum into a shell-and-tube heat exchanger, and uses the residual heat to circulate and heat the waste asphalt material in the recycled material bin. This achieves efficient recovery and utilization of flue gas waste heat, avoiding the energy waste and increased costs caused by direct discharge of waste heat or the use of complex hydrothermal and heat transfer oil systems in traditional equipment. At the same time, the waste heat recovery is closely integrated with the preheating of recycled materials, which improves the heating efficiency and blending ratio of recycled materials, significantly reduces the overall energy consumption of mixed material production, and solves the technical problem of low utilization rate and high production cost of recycled materials due to the lack of efficient preheating methods in the background technology.

[0011] 2. This utility model adopts a closed-loop hot air circulation structure. The air is driven by a circulating fan to return from the top of the recycled material bin. After heat exchange and heating, the air is evenly sent into the bin from the bottom air distribution plate, forming a stable airflow from bottom to top. This allows the hot air to fully penetrate the material layer, ensuring uniform heating and avoiding local overheating or short circuits. This improves the preheating quality of the recycled material. At the same time, the system has a simple structure and stable operation, requiring no complex auxiliary equipment. It is particularly suitable for energy-saving renovation of small and medium-sized asphalt mixing plants and has good economic benefits and promotional value. Attached Figure Description

[0012] Figure 1 A first-view perspective perspective view provided for this utility model; Figure 2 A cross-sectional view provided for this utility model; Figure 3 This is a partial schematic diagram of the present invention.

[0013] The following are the labels in the diagram: 1. Drying drum; 2. Drum exhaust pipe; 301. Shell and tube heat exchanger; 302. Flue gas inlet; 303. Air inlet; 304. Air outlet; 305. Flue gas outlet; 4. Return air duct; 5. Hot air duct; 6. Recycled material silo; 7. Air distribution plate; 8. Circulating fan. Detailed Implementation

[0014] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0015] Please refer to the following: Figures 1 to 3 A waste heat recovery device for asphalt production, comprising: Drying drum 1; The circulation assembly includes a drum exhaust pipe 2, a shell-and-tube heat exchanger 301, a return air duct 4, a hot air duct 5, a recycled material bin 6, and a circulating fan 8. The shell-and-tube heat exchanger 301 has a flue gas inlet 302 and a flue gas outlet 305 at both ends, and an air inlet 303 and an air outlet 304 at both ends of the circumferential surface of the shell-and-tube heat exchanger 301. One end of the drum exhaust pipe 2 is connected to the exhaust port of the drying drum 1, and the other end is connected to the flue gas inlet 302; The shell-and-tube flue gas outlet 305 is used to connect to the dust removal system; One end of the hot air duct 5 is connected to the air outlet 304, and the other end is connected to the bottom of the recycled material bin 6, which is used to send heated air into the recycled material bin. One end of the return air duct 4 is connected to the vent at the top of the side wall of the recycled material silo 6, and the other end is connected to the air intake of the circulating fan 8. The outlet of the circulating fan 8 is connected to the air inlet 303 to form a closed hot air circulation loop; The bottom of the recycled material silo 6 is equipped with an air distribution plate 7. Hot air passes through the air distribution plate 7 from bottom to top through the recycled material layer to achieve uniform heating.

[0016] In the specific implementation process, the recycled material is firstly waste asphalt mixture (RAP) recovered from road milling. Before use, it is stored in the recycled material silo 6. The high-temperature flue gas generated when the drying drum 1 is working enters the flue gas inlet 302 of the shell-and-tube heat exchanger 301 through the drum exhaust pipe 2. The flue gas flows in the internal pipes of the shell-and-tube heat exchanger and transfers heat outward. At the same time, the hot and humid air in the recycled material silo 6 is drawn out from the top through the return air pipe 4 and then enters the circulating fan 8. The circulating fan 8 pressurizes the air and sends it into the air inlet 303 of the shell-and-tube heat exchanger 301. The air is heated into hot air by the flue gas in the heat exchanger 301 and then discharged from the air outlet 304. The hot air enters the bottom of the recycled material silo 6 through the hot air pipe 5 and is then evenly blown upward into the recycled material through the air distribution plate 7 for heating. The heated hot and humid air is discharged from the top of the silo again and enters the return air pipe 4, forming a closed loop. In this way, the waste heat of the flue gas can be continuously used to preheat the recycled material, reducing energy waste, improving heating uniformity, and reducing production costs.

[0017] refer to Figures 1 to 3 As shown, the air distribution plate 7 has multiple evenly distributed through holes with a diameter of 5 to 20 mm, which are used to distribute hot air evenly and prevent recycled material from leaking down.

[0018] In the above embodiment, the air distribution plate 7 has a number of uniform small holes. These holes are of moderate size, which can ensure that the hot air passes through smoothly and diffuses evenly throughout the material layer, while preventing recycled material particles from falling into the holes and causing blockage or material loss. During the process of hot air penetrating the recycled material from bottom to top, the problem of local overheating or insufficient heating is avoided, making the waste asphalt material more evenly heated, improving the preheating effect and subsequent mixing quality.

[0019] refer to Figures 1 to 3 As shown, circulating fan 8 is a high-temperature resistant centrifugal fan.

[0020] In the above embodiment, the circulating fan 8 is installed on the return air duct 4, located between the top of the recycled material silo 6 and the air inlet 303 of the shell-and-tube heat exchanger 301. The circulating fan 8 adopts a high-temperature resistant centrifugal structure, which can operate stably under long-term contact with humid and hot air of 60℃~80℃, and will not be damaged due to excessive temperature. This ensures the continuity and reliability of the entire hot air circulation system, reduces the number of downtime maintenance, and improves the service life of the equipment.

[0021] refer to Figures 1 to 3 As shown, both the hot air duct 5 and the return air duct 4 are made of metal, and both the hot air duct 5 and the return air duct 4 have an insulation layer on their circumferential surfaces to reduce heat loss.

[0022] In the above embodiments, both the hot air duct 5 and the return air duct 4 are made of metal and wrapped with a layer of insulation material on the outer wall. This can effectively reduce the heat loss of hot air during the transportation process, especially in winter or when the ambient temperature is low, so that the incoming air temperature can still be maintained at a high level. At the same time, the return air duct 4 can also prevent condensation on the surface and avoid water vapor condensation from affecting the operation of the circulating fan 8, thereby improving the overall thermal efficiency and operational stability of the system.

[0023] The working principle of the waste heat recovery equipment for asphalt production provided by this utility model is as follows: Firstly, the recycled material is waste asphalt mixture (RAP) recovered from road milling. Before use, it is stored in the recycled material silo 6. Then, the high-temperature flue gas discharged from the drying drum 1 enters the flue gas inlet 302 of the shell-and-tube heat exchanger 301 through the drum exhaust pipe 2. Inside the heat exchanger, heat is transferred to the outside air through the tube walls. The cooled flue gas is discharged from the flue gas outlet 305 to the dust removal system. Simultaneously, the humid and hot air inside the recycled material silo 6 is collected by the return air duct 4 from the top exhaust port, pressurized by the circulating fan 8, and sent to the air inlet 303 of the shell-and-tube heat exchanger 301. The air is then cooled by the flue gas... After being heated by waste heat, the air is discharged from air outlet 304 and transported to the bottom of the recycled material silo 6 through hot air duct 5. Then, it is evenly blown upwards into the recycled material through air distribution plate 7 for continuous preheating. The heated humid air is discharged from the top of the silo again, forming a closed hot air circulation. This structure makes full use of the waste heat of flue gas to directly heat the recycled material, avoiding the drawbacks of direct discharge of waste heat or the use of complex hydrothermal or heat transfer oil systems in traditional methods. It solves the problems of lack of efficient recycled material preheating methods, low recycled material blending rate, high mixing energy consumption, and energy waste caused by the failure to combine waste heat of flue gas with recycled material preheating in existing technologies.

[0024] The above are merely embodiments of this utility model and do not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the description and drawings of this utility model, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A waste heat recovery device for asphalt production, characterized in that, include: Drying drum (1); The circulation assembly includes a drum exhaust pipe (2), a shell-and-tube heat exchanger (301), a return air duct (4), a hot air duct (5), a recycled material bin (6), and a circulating fan (8). The shell-and-tube heat exchanger (301) has a flue gas inlet (302) and a flue gas outlet (305) at both ends, and an air inlet (303) and an air outlet (304) at both ends of the circumferential surface of the shell-and-tube heat exchanger (301). One end of the drum exhaust pipe (2) is connected to the exhaust port of the drying drum (1), and the other end is connected to the flue gas inlet (302). The flue gas outlet (305) is used to connect to the dust removal system; One end of the hot air duct (5) is connected to the air outlet (304), and the other end is connected to the bottom of the recycled material bin (6) for sending heated air into the recycled material bin; One end of the return air duct (4) is connected to the vent at the top of the side wall of the recycled material silo (6), and the other end is connected to the air intake of the circulating fan (8); The outlet of the circulating fan (8) is connected to the air inlet (303) to form a closed hot air circulation loop; The bottom of the recycled material silo (6) is provided with an air distribution plate (7), through which hot air penetrates the recycled material layer from bottom to top to achieve uniform heating.

2. The waste heat recovery equipment for asphalt production according to claim 1, characterized in that, The air distribution plate (7) is provided with multiple evenly distributed through holes with a diameter of 5 to 20 mm, which are used to distribute hot air evenly and prevent recycled material from leaking down.

3. The waste heat recovery equipment for asphalt production according to claim 1, characterized in that, The circulating fan (8) is a high-temperature resistant centrifugal fan.

4. The waste heat recovery equipment for asphalt production according to claim 2, characterized in that, Both the hot air duct (5) and the return air duct (4) are made of metal, and both the hot air duct (5) and the return air duct (4) have an insulation layer on their circumferential surfaces to reduce heat loss.

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